JP2805866B2 - Electrophotographic photoreceptor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photoreceptor, and more particularly, a novel titanyl phthalocyanine composition crystal is used as an active ingredient of a charge generating agent, and a predetermined compound is used as a charge transfer agent. The present invention relates to an electrophotographic photoreceptor as an active ingredient of

[Prior Art] Conventionally, phthalocyanines and metal phthalocyanines have been known to exhibit excellent photoconductivity, and some of them have been used for electrophotographic photoreceptors. In recent years, with the development of non-impact printer technology, electrophotographic optical printers that use laser light and LEDs as light sources and are capable of high image quality and high speed are becoming widespread, and photoconductors that can meet these demands are being actively developed. It is.

In particular, when a laser is used as a light source, semiconductor lasers are often used because of their small size, low cost, simplicity, and the like. However, the oscillation wavelength of the semiconductor lasers currently used in these lasers is relatively long in the near infrared region. Limited. Therefore, it is inappropriate to use a photoreceptor that has sensitivity in the visible region, which has been used in conventional electrophotographic copiers, for semiconductor lasers. It has become to.

As organic materials meeting this requirement, conventionally, methine squaric acid dyes, indoline dyes, cyanine dyes, pyrylium dyes, polyazo dyes, phthalocyanine dyes, naphthoquinone dyes and the like have been known. Of these, methine squaric acid dyes, indoline dyes, cyanine dyes, and pyrylium dyes can be made longer in wavelength, but lack practical stability (repeating characteristics), and polyazo dyes are difficult to make longer in wavelength. In addition, it is disadvantageous in terms of production and naphthoquinone dyes have difficulty in sensitivity at present.

In contrast, phthalocyanine dyes have a spectral sensitivity peak in the long wavelength region of 600 nm or more, and also have high sensitivity,
Since the spectral sensitivity varies depending on the type of the central metal and the crystal form, it is considered to be suitable as a dye for a semiconductor laser, and research and development are being vigorously conducted.

Among the phthalocyanine compounds studied so far,
Examples of the compound exhibiting high sensitivity in a long wavelength region of 780 nm or more include X-type metal-free phthalocyanine, ε-type copper phthalocyanine, and vanadyl phthalocyanine.

On the other hand, in order to increase the sensitivity, a stacked photoreceptor using a phthalocyanine deposited film as a charge generation layer has been studied.
Some phthalocyanines having a group Ia or group IV metal as a central metal having relatively high sensitivity have been obtained. References relating to such metal phthalocyanines include, for example, JP-A-57-211149 and JP-A-57-1487.
No. 45, No. 59-36254, No. 59-44054, No.
JP-A-59-30541, JP-A-59-31965, JP-A-59-166959 and the like. However, the production of the vapor-deposited film requires a high-vacuum evacuation apparatus, and the equipment cost is high. Therefore, the organic photoreceptor as described above must be expensive.

On the other hand, using phthalocyanine not as a vapor deposition film but as a resin dispersion layer and using this as a charge generation layer,
A composite photoreceptor having a charge transfer layer applied thereon has also been studied.

As a charge transfer agent, as disclosed in JP-A-54-59143, high sensitivity and low residual potential, and low light fatigue even when used repeatedly according to an electrophotographic process,
Hydrazone compounds with excellent durability have been developed. Also, as disclosed in JP-A-61-32850, a triphenylmethane compound having high sensitivity, low residual potential, low light fatigue even when repeatedly used according to an electrophotographic process, and excellent durability has been developed. Have been.

Further, as composite photoreceptors, there are those using metal-free phthalocyanine (Japanese Patent Application No. 57-66963) and indium phthalocyanine (Japanese Patent Application No. 59-220493), which are relatively high-sensitivity photoreceptors. However, the former has drawbacks such as a rapid decrease in sensitivity in the long wavelength region of 800 nm or more, and the latter has insufficient sensitivity for practical use when the charge generation layer is made of a resin dispersion. It has disadvantages such as

[Problems to be Solved by the Invention] Particularly in recent years, studies have been made on the use of titanyl phthalocyanine having relatively high sensitivity electrophotographic properties (JP-A-59-49544, JP-A-61-23928, same
It is known that there are differences in characteristics depending on various crystal forms. In order to form these various crystal forms, special purification and special solvent treatment are required. The treatment solvent is different from that used when forming the dispersion coating film. This is because various types of crystals obtained are easy to grow in a growth treatment solvent, and when this solvent is used as a coating solvent, it is difficult to control the crystal form and particle size, and the paint is not stable. This is because the electrical characteristics are deteriorated and are not suitable for practical use. For this reason, chlorine-based solvents such as chloroform, which do not easily promote crystal growth, are usually used when forming paint, but these solvents do not always have good dispersibility in titanyl phthalocyanine, and the dispersion stability of paint is not sufficient. Is a problem.

On the other hand, titanyl phthalocyanine generally has a large ionization potential, and when used together with a hydrazone compound having a small ionization potential, a large difference in ionization potential makes it easy to inject holes from the titanyl phthalocyanine to the hydrazone compound. Therefore, the chargeability is poor and the durability is poor. In the case of using a photoreceptor of a dispersion system containing a charge generating agent and a charge transfer agent in a single layer, it is difficult to include a large amount of the charge generating agent for improving the sensitivity while maintaining the chargeability. There is.

The present invention has been made to solve the conventional problems as described above, and in an electrophotographic photoreceptor containing a charge generating agent and a charge transfer agent, a titanyl phthalocyanine composition crystal having excellent photoconductivity. An object of the present invention is to provide an electrophotographic photoreceptor having high sensitivity and excellent charge retention and durability by using a charge generating agent and a specific compound as a charge transfer agent.

[Means for Solving the Problems] The present invention relates to an electrophotographic photoreceptor containing a charge generating agent and a charge transfer agent, wherein (a) the charge generating agent is a metal-free phthalocyanine nitrogen isoform, a metal phthalocyanine nitrogen isoform, Metal phthalocyanine, metal phthalocyanine, metal-free naphthalocyanine or metal naphthalocyanine (however, metal-free phthalocyanine nitrogen isoform, metal phthalocyanine nitrogen isoform, metal-free phthalocyanine and metal phthalocyanine may have a substituent on the benzene nucleus, A metal-free naphthalocyanine and a metal naphthalocyanine may have a substituent on a naphthyl nucleus), and a total of 50 parts by weight or less, and a titanyl phthalocyanine composition containing 100 parts by weight of titanyl phthalocyanine. Product crystal as an active ingredient, and the composition crystal has an infrared absorption spectrum. In the vector, 14
90 ± 2cm ^-1 , 1415 ± 2cm ^-1 , 1332 ± 2cm ^-1 , 1119 ± 2cm ^-1 ,
1072 ± 2cm- ¹ , 1060 ± 2cm- ¹ , 961 ± 2cm- ¹ , 893 ± 2cm- ¹ ,
It has strong absorption characteristic at 780 ± 2 cm ⁻¹ , 751 ± 2 cm ⁻¹ and 730 ± 2 cm ⁻¹ , and has a Bragg angle (2θ ± 0.2 degrees) of 27.3 in an X-ray diffraction spectrum using CuK as a source. Shows a maximum diffraction peak at 9.7 degrees and 24.1 degrees, or shows a Bragg angle (2θ ± 0.2 degrees) of 27.3 in an X-ray diffraction spectrum using CuK as a source.
Degree of maximum diffraction peak at 7.4 °, 22.3 °, 24.1 °
, 25.3 degrees, and 28.5 degrees, and (b) a charge transfer agent represented by the general formula [I]; (Wherein R ¹ is a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxyl group, a halogen,
A carbazono group may be formed together with a substituted or unsubstituted amino group, morphforno group, piperidino group or phenyl group, R ² represents a hydrogen atom, a substituted or unsubstituted alkyl group, and R ³ and R ⁴ represent a hydrogen atom A substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a ring such as a pyridyl group, a pyrrhodino group, a carbazono group, and the like; and a general formula [II]; (Where A is an electron donating group, R ⁵ is a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxyl group, R ⁶ and R ⁷ are the same or different and are each a hydrogen atom, substituted or unsubstituted A substituted alkyl group, a substituted or unsubstituted aralkyl group, or a substituted or unsubstituted aryl group) as an active ingredient.

According to the present invention, a difference in ionization potential from the titanyl phthalocyanine composition crystal can be compensated for by using the compounds represented by the general formulas [I] and [II] in combination as the charge transfer agent. It is possible to obtain an electrophotographic photoreceptor that has excellent sensitivity and chargeability, has little light fatigue even when used repeatedly according to an electrophotographic process, and has excellent durability.

 Hereinafter, the present invention will be described in detail.

The phthalocyanine compound used in the present invention, naphthalocyanine compound is a "phthalocyanine compound" of Moser and Thomas (Rheinhold, 1963),
Those obtained by a known method such as "phthalocyanine" (CRC Publishing, 1983) and other suitable methods are used.

For example, titanyl phthalocyanine can be easily synthesized from 1,2-dicyanobenzene (o-phthalodinitrile) or a derivative thereof and a metal or a metal compound according to a known method.

For example, in the case of titanyl phthalocyanines, they can be easily synthesized according to the following reaction formula (1) or (2).

(However, Pc represents a phthalocyanine residue.) As the organic solvent, nitrobenzene, quinoline, α-
High boiling organic solvents which are inert to the reaction of chloronaphthalene, β-chloronaphthalene, α-methylnaphthalene, methoxynaphthalene, diphenylether, diphenylmethane, diphenylethane, ethylene glycol dialkyl ether, diethylene glycol dialkyl ether, triethylene glycol dialkyl ether, etc. are preferred. The reaction temperature is usually from 150 to 300C, preferably from 200 to 250C.

In the present invention, the crude titanyl phthalocyanine compound thus obtained is used as it is or purified by the following method. In the case of purification, treatment with tetrahydrofuran is performed after non-crystallization treatment. At that time, after removing the organic solvent used for the condensation reaction using an appropriate organic solvent such as alcohols such as methanol, ethanol and isopropyl alcohol, and ethers such as tetrahydrofuran and 1,4-dioxane in advance, hot water Processing is preferred. In particular, the pH of the washing solution after hot water treatment is about 5
It is preferred to wash until it reaches ~ 7.

Subsequently, 2-ethoxyethanol, diglyme,
It is more preferable to treat with an electron-donating solvent such as dioxane, tetrahydrofuran, N, N-dimethylformamide, N-methylpyrrolidone, pyridine, morpholine and the like.

Next, as the phthalocyanine nitrogen isotope, there are various porphines, for example, tetrapyridinoporphyrazine in which one or more of the benzene nucleus of phthalocyanine is replaced with a quinoline nucleus, and the metal phthalocyanine includes
Examples include various substances such as copper, nickel, cobalt, zinc, tin, aluminum, and titanium.

In addition, examples of the substituent of phthalocyanines and naphthalocyanines include an amino group, a nitro group, an alkyl group, an alkoxy group, a cyano group, a mercapto group, and a halogen atom, and a sulfonic acid group, a carboxylic acid group, or a metal salt thereof. ,
Ammonium salts, amine salts and the like can be exemplified as relatively simple ones. Furthermore, various substituents can be introduced into the benzene nucleus via an alkylene group, a sulfonyl group, a carbonyl group, an imino group, etc., and these are conventionally known as an anti-aggregation agent or a crystal conversion inhibitor in the technical field of these conventional phthalocyanine pigments. (For example, see U.S. Pat. Nos. 3,973,981 and 4,088,507) or unknown. Known methods for introducing each substituent are omitted. In addition, those which are not publicly known are described as synthesis examples in Examples.

In the present invention, titanyl phthalocyanine and a metal-free and metal phthalocyanine nitrogen isoform which may have a substituent on a benzene nucleus, a metal-free and metal-free and metal naphthalocyanine which may have a substituent on a metal phthalocyanine or a naphthyl nucleus The composition ratio is preferably 100/50 (weight ratio) or more, but is desirably 100/20 to 0.1 (weight ratio).
And At 100 / 0.1 or more, the crystals contain many single crystals in addition to the mixed crystal composition, and the infrared absorption spectrum and X
In some cases, it is difficult to distinguish the novel material of the present invention from the line diffraction spectrum (hereinafter, these mixed compositions are referred to as titanyl phthalocyanine compositions).

The titanyl phthalocyanine composition of the present invention is obtained by mixing titanyl phthalocyanine and other phthalocyanines,
It can be produced by treating and crystallizing the non-crystalline composition of the mixture with tetrahydrofuran.

The amorphous titanyl phthalocyanine composition can be obtained by a single chemical method or mechanical method, but more preferably by a combination of various methods.

For example, non-crystalline particles can be obtained by weakening agglomeration between particles by a method such as an acid pasting method or an acid slurry method and then grinding by a mechanical treatment method. The equipment used during milling includes kneaders,
Banbury mixer, attritor, edge runner mill, roll mill, ball mill, sand mill, SPEX mill,
Examples include, but are not limited to, homomixers, dispersers, agitators, jaw crushers, stamp mills, cutter mills, micronizers, and the like. The acid pasting method, which is well known as a chemical treatment method, is a method in which a pigment is dissolved or sulfated in 95% or more sulfuric acid and poured into water or ice water to reprecipitate. Is desirably maintained at 5 ° C. or lower, and by slowly injecting sulfuric acid into water stirred at a high speed, amorphous particles can be obtained under even better conditions.

In addition, there are a method in which the crystalline particles are directly ground by a mechanical processing device for a very long time, a method in which the particles obtained by the acid pasting method are treated with the solvent or the like, and then ground.

Amorphous particles can also be obtained by sublimation. For example,
Each raw material obtained by various methods under vacuum is 500 ~ 6
It can be obtained by sublimation by heating to 00 ° C. and promptly co-evaporation deposition on a substrate.

The amorphous titanyl phthalocyanine composition obtained as described above is treated in tetrahydrofuran,
Obtain new stable crystals. As a treatment method of tetrahydrofuran, 5-300 parts by weight of tetrahydrofuran is added to 1 part by weight of the amorphous titanyl phthalocyanine composition in various stirring tanks, and the mixture is stirred. The temperature can be either heating or cooling, but if heated, the crystal growth will be faster,
Also, it becomes slow at low temperatures. As the stirring tank, in addition to a normal stirrer, an ultrasonic ball mill, a sand mill, a homomixer, a disperser, an agitator, a micronizer, or the like, which is used for dispersion, or a mixer such as a concal blender V-type mixer is appropriately used. Used, but not limited to.

After these stirring steps, filtration, washing and drying are usually performed to obtain stabilized titanyl phthalocyanine composition crystals. At this time, a resin or the like can be added to the dispersion liquid as required without filtering and drying, and the dispersion can be made into a coating. When used as a coating film of an electrophotographic photoreceptor or the like, the process is omitted and it is extremely effective.

FIG. 1 shows the infrared absorption spectrum of the titanyl phthalocyanine composition of the present invention thus obtained. The titanyl phthalocyanine composition has an absorption wave number (cm ⁻¹ , including an error of ± 2) of 1490, 1415, 1332,
It shows characteristic strong peaks at points 1119, 1060, 961, 893, 780, 751, and 730, and shows specific peaks at 1480, 1365, 1165, and 1003.

For reference, the infrared absorption spectrum of titanyl phthalocyanine treated with N-methylpyrrolidone is shown in FIG. 2 and the acid paste method [α described in “Phthalocyanine compound” by Moser and Thomas (published in 1963) ”
Processing Method for Obtaining Form Phthalocyanine] The infrared absorption spectrum of titanyl phthalocyanine
Shown in the figure. These infrared absorption spectra indicate that the titanyl phthalocyanine composition obtained by the above method is novel.

4 to 6 show X-ray diffraction diagrams using CuK rays. This titanyl phthalocyanine composition shows a diffraction peak having a maximum Bragg angle 2θ (including an error range of ± 0.2 degrees) at 27.3 degrees in an X-ray diffraction diagram,
Strong peaks at 9.7 degrees and 24.1 degrees, and maximum peaks at 27.3 degrees, 7.4 degrees, 22.3 degrees, 24.1 degrees, 25.3 degrees, 2
Some show a strong peak at 8.5 degrees. It is considered that these differences are generally attributable to the fact that the intensity of the diffraction line is substantially proportional to the size of each crystal face, so that the degree of growth of each crystal face of the same structure crystal is different.

The titanyl phthalocyanine composition of the present invention is a very stable and excellent crystal which does not show a large change in the infrared absorption spectrum even when the crystal growth is promoted by further heating and stirring in tetrahydrofuran.

One of the charge transfer agents used in the present invention is represented by the general formula [I], (In the formula, R ¹ , R ² , R ³ and R ⁴ have the same meanings as described above.) Particularly, the compound represented by the formula [III] is effective.

The compound represented by the general formula [I] can be easily synthesized by a conventional method. For example, J. Pacansky et al., (Radiation Physics and Chemistry (Radiat. Phy
s. Chem.), Vol. 29, No. 3, pp. 219-225, 1987).

In particular, (Wherein R ¹ , R ² , R ³ and R ⁴ have the same meaning as described above) in a molar ratio of 1: 1 to 2: 1 and a mineral acid such as hydrochloric acid is used as a catalyst, It can be easily synthesized in ethanol.

Specific examples of the compound represented by the general formula [II] include those shown in Table 1, but similar compounds are effective and are not necessarily limited thereto.

These can be synthesized by a conventional method. For example, Yoshino
Shino) et al., Tokyo Industrial Laboratory Report (Rep. Gov. Chem. Ind.
s. Inst. Tokyo), 37 , 95, 111 (1942), and U.S. Pat.

Specifically, the compound represented by the general formula [II] is represented by the general formula [IV]; (Wherein A and R ⁵ have the same meanings as described above), and a general formula [V]; R ⁶ R ⁷ C ＝ O... [V] (wherein R ⁶ and R ⁷ are Having the same meaning as described above) are added in a molar ratio of 4: 1 to 2: 1 respectively, and are easily synthesized by using a mineral acid such as hydrochloric acid or anhydrous zinc chloride as a catalyst. Can be.
Further, if necessary, a solvent such as methanol, ethanol, dioxane, chloroform, benzene, etc. may be used.

The electrophotographic photoreceptor of the present invention is preferably formed by laminating an undercoat layer, a charge generation layer and a charge transfer layer in this order on a conductive substrate, but in the order of an undercoat layer, a charge transfer layer and a charge generation layer. It may be a laminated product or a product in which a charge generating agent and a charge transfer agent are dispersed and coated with an appropriate resin on an undercoat layer. Further, these undercoat layers can be omitted as necessary.

Examples of the conductive substrate used in the present invention include a metal plate made of aluminum, nickel, chromium, etc., a metal drum or a metal foil, and a plastic film and a conductive material provided with a thin layer of aluminum, tin oxide, indium oxide, chromium, etc. A paper or a plastic film coated or impregnated with is used.

By coating a suitable binder on a substrate using the titanyl phthalocyanine composition according to the present invention as a charge generating agent, a charge generating layer having extremely good dispersibility and extremely high photoelectric conversion efficiency can be obtained.

Coating is performed using a spin coater, an applicator, a spray coater, a bar coater, an immersion coater, a doctor blade, a roller coater, a curtain coater, a bead coater device, and drying is desirably heated to 40 to 200 ° C. for 10 minutes. Perform under static or blast conditions for up to 6 hours. The film thickness after drying is 0.01 to 5 μm, preferably
Coating is performed so as to be 0.1 to 1 μm.

The binder that can be used when forming the charge generation layer by coating can be selected from a wide range of insulating resins, and can be selected from organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinylanthracene, and polyvinylpyrene. Preferably, polyvinyl butyral, polyarylate (such as a condensation polymer of bisphenol A and phthalic acid), polycarbonate, polyester, phenoxy resin, beer acetate, acrylic resin, polyacrylamide resin, polyamide, polyvinylpyridine, cellulose resin, and urethane resin , Epoxy resin, silicone resin,
Examples thereof include insulating resins such as polystyrene, polyketone, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetal, polyacrylonitrile, phenolic resin, melamine resin, casein, polyvinyl alcohol, and polyvinylpyrrolidone. The amount of the resin contained in the charge generation layer is 100% by weight or less, preferably 40% by weight or less. These resins may be used alone or in combination of two or more.

The solvent for dissolving these resins differs depending on the type of the resin, and is preferably selected from those which do not affect the later-described charge transfer layer or undercoat layer during coating. Specifically, aromatic hydrocarbons such as benzene, xylene, ligroin, monochlorobenzene, and dichlorobenzene; ketones such as acetone, methyl ethyl ketone and cyclohexanone; alcohols such as methanol, ethanol and isopropanol; ethyl acetate and methyl cellosolve; Esters, carbon tetrachloride, aliphatic halogenated hydrocarbons such as chloroform, dichloromethane, dichloroethane, trichloroethylene, ethers such as tetrahydrofuran, dioxane, ethylene glycol monomethyl ether, N, N-dimethylformamide, N, N
Amides such as dimethylacetamide and sulfoxides such as dimethylsulfoxide are used.

Further, the charge transfer layer can be formed by dissolving the compounds represented by the above general formulas [I] and [II] in a suitable binder and applying the same. The mixing ratio of the compound represented by the general formula [II] to the general formula [I] is preferably 0.05 to 90 wt%, particularly preferably 20 to 50 wt%. As the binder and the organic solvent used when forming the charge transfer layer by coating, those used when forming the charge generation layer as described above can be similarly used. The total amount of the compounds represented by the general formulas [I] and [II] contained in the charge transfer layer is 10 to 90% by weight, preferably 30 to 65% by weight. If necessary, a plasticizer or the like can be used together with the binder.

The charge transfer layer is electrically connected to the above-described charge generation layer, receives charge carriers injected from the charge generation layer in the presence of an electric field, and moves these charge carriers to the surface of the photoreceptor or the support. The charge transfer layer may be stacked on the charge generation layer, or may be stacked thereunder. However, it is desirable that the charge transfer layer be laminated on the charge generation layer. At this time, the thickness of the charge transfer layer is 3 to 50 μm, preferably 5 to 20 μm.

Further, 5 to 40% by weight of the titanyl phthalocyanine composition of the present invention and 10 to 70% by weight of the charge transfer agent are kneaded with respect to the binder resin usually used for the charge transfer layer,
It is also possible to produce a single layer photoreceptor of preferably 15 to 30 μm. As a result, a positively charged photoconductor having stable chargeability and sensitivity can be obtained.

Further, an undercoat layer having a barrier function and an adhesive function can be provided between the conductive support and the photosensitive member. The undercoat layer is made of casein, polyvinyl alcohol,
It can be formed of nitrocellulose, ethylene-acrylic acid copolymer, polyamide, polyurethane, gelatin, aluminum oxide, zinc oxide and the like. The film thickness of the undercoat layer is suitably from 0.1 to 5 μm, preferably about 0.5 to 3 μm.

The electrophotographic photoreceptor of the present invention has an absorption peak at a wavelength near 800 nm, as shown in the spectral sensitivity characteristic diagram of FIG.
The present invention can be applied not only to a copying machine and a printer as an electrophotographic photosensitive member but also to various other optical storage devices.

[Examples] Hereinafter, the present invention will be described in detail, but the present invention is not limited to the following examples unless it exceeds the gist.

 In addition, in an example, a part shows a weight part.

Production of Phthalocyanines Synthesis Example 1 After 20.4 parts of o-phthalodinitrile and 7.6 parts of titanium tetrachloride were heated and reacted in 50 parts of quinoline at 200 ° C. for 2 hours, the solvent was removed by steam distillation, followed by a 2% aqueous hydrochloric acid solution. The product was purified with a 2% aqueous sodium hydroxide solution, washed with methanol and N, N-dimethylformamide, and dried to obtain 21.3 parts of titanyl phthalocyanine (TIOPc).

Synthesis Example 2 14.5 parts of aminoiminoisoindolenine was heated in 50 parts of quinoline at 200 ° C. for 2 hours. After the reaction, the solvent was removed by steam distillation, and the mixture was purified with a 2% aqueous hydrochloric acid solution and subsequently with a 2% aqueous sodium hydroxide solution. After that, the resultant was sufficiently washed with methanol and N, N-dimethylformamide, and dried to obtain 8.8 parts of metal-free phthalocyanine (yield: 70%).

Synthesis Example 3 20 parts of o-naphthalodinitrile were added to 50 parts of quinoline in 200
After heating at 4 ° C. for 4 hours, the reaction mixture was purified with a 2% aqueous hydrochloric acid solution, washed with methanol and N, N-dimethylformamide, and dried to obtain 15 parts of a metal-free naphthalocyanine.

Synthesis Example 4 A mixture of 15 parts of a metal-free or metal phthalocyanine, 500 parts of dichlorotoluene, 25 parts of acetyl chloride and 70 parts of aluminum chloride was stirred at 60 to 80 ° C. for 8 hours, then poured into water, and the solid content was filtered. After washing with water and drying, a compound represented by the following formula was obtained.

MPc (COCH ₂ Cl) _1.3 (wherein, M represents H ₂ , Cu, TiO, Zn, etc., MPc represents a phthalocyanine residue, and the number outside parentheses represents the average number of substitutions by analysis; the same applies hereinafter) And various amines were reacted by a known method to obtain various phthalocyanine derivatives.

By reducing these various phthalocyanine derivatives by a known method, a general formula; (Wherein R ⁸ and R ⁹ are a hydrogen atom, an alkyl group, an aryl group,
And a hetero group or a nitrogen atom may form a hetero ring with R ⁸ and R ⁹ ).

For example, a phthalocyanine derivative represented by the following formula; Is reduced by dissolving 6 parts of potassium hydroxide in 80 parts of diethylene glycol, pulverizing the above phthalocyanine derivative 6 parts sufficiently finely, and further adding hydrazine hydrate.
Add 10 parts gradually and reflux for about 10 hours. The obtained deep blue slurry is poured into water, filtered, washed with water and dried.

 Table 2 shows the obtained phthalocyanine derivatives.

Synthesis Example 5 Metal-free phthalocyanine, copper phthalocyanine, nickel phthalocyanine, cobalt phthalocyanine, and titanyl phthalocyanine, which were chlorsulfonated by an ordinary method, were reacted with various amines to obtain phthalocyanine derivatives shown in Table-3.

Production of hydrazone compound represented by general formula [I] Synthesis Example 6 One drop of 1N hydrochloric acid was added as a catalyst to 2.02 g of diphenylhydrazine and 1.77 g of p-diethylaminobenzaldehyde, and the mixture was stirred at room temperature for about 1 hour in 5 cc of ethanol. Do
After filtration and washing with ethanol, 2.2 g of crystals were obtained after drying. Yield 76%.

Synthesis Example 7 One drop of 1N hydrochloric acid was added as a catalyst to 2.13 g of diphenylhydrazine and 2.80 g of p-diphenylaminobenzaldehyde, and the mixture was stirred for about 1 hour at room temperature in 5 cc of ethanol, followed by filtration and washing with ethanol. 1.9g after drying
Was obtained. Yield 53%.

Production of Compound Represented by General Formula [II] Synthesis Example 8 (Exemplary Compound No. 2 (see Table 1)) 16.4 g of N, N-diethylamino-m-toluidine and 4.8 g of benzaldehyde are heated and stirred at an internal temperature of 80 ° C. Then, as soon as a uniform solution is obtained, 10.0 g of concentrated hydrochloric acid is added dropwise. Thereafter, the internal temperature was raised to 120 ° C., and the mixture was heated and stirred at the same temperature for about 10 hours. The reaction is cooled to room temperature and then a 10% aqueous sodium bicarbonate solution is added until neutral. Further, the target substance is extracted with 150 cc of ethyl acetate. After dehydration with sodium sulfate, ethyl acetate is distilled off by an evaporator. Residual candy is ethanol
Recrystallization from 100 cc yields 9.2 g of a white powder. Its melting point was 110.0-111.5 ° C.

Synthesis Example 9 (Exemplified Compound No. 10) 16.4 g of N, N-diethylamino-m-toluidine was reacted with 6.4 g of 4-dimethylamino-2-methylbenzaldehyde in the same manner as in Synthesis Example 8 to give a white color having a melting point of 124 to 127 ° C. 9.2g powder
I got

Synthesis Example 10 (Exemplified Compound No. 20) 10.3 g of N, N-dimethylamino-m-toluidine and 4.8 g of p-methylbenzaldehyde were reacted in the same manner as in Synthesis Example 8 to obtain 7.7 g of a white powder having a melting point of 130 to 140 ° C. Obtained.

Production of Electrophotographic Photoreceptor Example 1 100 parts of titanyl phthalocyanine obtained in Synthesis Example 1 and 10 parts of the derivative shown in Table 2 obtained in Synthesis Part 4-a were dissolved in ice-cooled 98% sulfuric acid, and dissolved in water. , And filtered, washed with water and dried to obtain a uniform composition of both. 10 parts of this composition was stirred in 200 parts of tetrahydrofuran (THF) for about 5 hours, filtered, washed, and dried to obtain 9.5 parts of a titanyl phthalocyanine composition.

The infrared absorption spectrum of the composition thus obtained was new as shown in FIG. The X-ray diffraction pattern was as shown in FIG.

The titanyl phthalocyanine composition obtained in this manner was 0.1.
4 g was dispersed in a ball mill together with 0.3 g of polyvinyl butyral and 30 g of THF. This dispersion was applied on a polyester film having an aluminum vapor-deposited layer so as to have a dry film thickness of 0.2 μm using a film applicator, and dried at 100 ° C. for 1 hour to obtain a charge generation layer.

On the charge generation layer thus obtained, 70 parts of the hydrazone compound shown in the above Synthesis Example 6 and 30 parts of the triphenylmethane derivative of the exemplified compound (No. 2) as a charge transfer agent and a polycarbonate resin (Mitsubishi Gas Co., Ltd.) Chemical Z-200) 100
Part of the solution was dissolved in 500 parts of toluene / tetrahydrofuran (1/1) to form a charge transfer layer by applying a solution having a dry film thickness of 15 μm to obtain an electrophotographic photosensitive member having a laminated photosensitive layer. .

This photoreceptor is used in an electrostatic copying paper tester (Kawaguchi Electric Works E
Using PA-8100), the photoreceptor was first pre-exposed for 0.8 seconds, charged in a dark place by a corona discharge of -5.0 kV and left for 0.9 seconds, and then exposed to white light of 5 lux for 0.2 seconds,
The measurement of pausing for 0.8 seconds is repeated 2000 times, and the change in the initial charge potential (dV ₀ ) from the first time to the 2000th time, the potential holding ratio (V _0.9 / V ₀ ) for 0.9 seconds and the surface potential attenuate by half The required exposure amount E _1/2 (lux · sec) was determined and the results are shown in Table 4 (V ₀ is the initial charge position, V _0.9 is the charge position after 0.9 seconds).

Examples 2 to 6 Synthesis Example 8 using the synthesis method of Yoshino et al.
Compounds Nos. 2, 4, 10, 20, 30 (Table 1)
The photoreceptor was prepared in the same manner as in Example 1 using these compounds together with the hydrazone compound shown in Synthesis Example 6 as a charge transfer agent, and the potential characteristics thereof were examined. Table 4 shows the results.

Example 7 One part of the titanyl phthalocyanine obtained in Synthesis Example 1 and 0.05 part of the metal-free phthalocyanine obtained in Synthesis Example 2 were gradually dissolved in 30 parts of 98% sulfuric acid at 5 ° C., and the mixture was stirred for about 1 hour.
Stir while keeping the temperature below 5 ° C. Subsequently, the sulfuric acid solution is slowly poured into 500 parts of ice water with high-speed stirring, and the precipitated homogeneous composition is filtered. This is washed with distilled water until no acid remains, to obtain a wet cake. The cake was stirred in 100 parts of tetrahydrofuran (assuming that the amount of phthalocyanine contained was 1 part) for about 1 hour, filtered and washed with tetrahydrofuran, and a tetrahydrofuran dispersion of titanyl phthalocyanine composition crystals having a pigment content of 0.95 parts was obtained. I got After drying partially, the infrared absorption spectrum and the X-ray diffraction image were examined. As a result, the infrared absorption spectrum was the same as in FIG. 1, and the X-ray diffraction pattern was as shown in FIG.

Next, a coating material was prepared using an ultrasonic disperser so that the composition was 1.5 parts by dry weight, 1 part of butyral resin (BX-5 manufactured by Sekisui Chemical) and 80 parts of tetrahydrofuran. This dispersion was coated with a polyamide resin (CM-8000, manufactured by Toray Industries, Inc.) 0.5 μm.
The resultant was coated on a coated aluminum plate so that the dry film thickness became 0.2 μm to obtain a charge generation layer.

The subsequent steps were performed in the same manner as in Example 1 to prepare a photoreceptor, and its characteristics were evaluated. Table 4 shows the results.

Example 8 Synthesis Example 3 in place of metal-free phthalocyanine of Example 7
A sample was prepared in the same manner as in Example 7, except that 0.05 parts of the metal-free naphthalocyanine obtained in the above was used. The infrared absorption spectrum was the same as in FIG. 1, and the X-ray diffraction image was as shown in FIG. Then, a photoreceptor was manufactured in the same manner as in Example 1, and its characteristics were measured and evaluated. Table 4 shows the results.

Example 9 Copper tetrapyridinoporphyrazine was synthesized by a known method.

100 parts of titanyl phthalocyanine and 10 parts of the above copper tetrapyridinoporphyrazine were dissolved in concentrated sulfuric acid, poured into water, filtered, washed with water and dried to obtain uniform and fine crystals. As a result of washing with tetrahydrofuran in the same manner as in Example 7, the infrared absorption spectrum was as shown in FIG. Hereinafter, a photoreceptor was prepared in the same manner as in Example 1, and its characteristics were measured and evaluated. Table 4 shows the results.

Comparative Example 1 A photoconductor was prepared in the same manner as in Example 1 except that only the hydrazone compound shown in Synthesis Example 6 was used as the charge transfer agent, and the potential characteristics were measured and evaluated. Table 4 shows the results.

Comparative Example 2 A photoconductor was prepared in the same manner as in Example 1 except that only the hydrazone compound shown in Synthesis Example 7 was used as the charge transfer agent, and the potential characteristics were measured and evaluated. Table 4 shows the results.

[Effect of the Invention] As described above, the electrophotographic photoreceptor of the present invention uses a novel and stable composition crystal as a charge generating agent,
Since the composition crystal is stable to a solvent, when a coating material is used, a solvent can be easily selected, and a coating material having good dispersion and a long life can be obtained. It will be easier.

In particular, the electrophotographic photoreceptor obtained by combining the compounds of the general formulas [I] and [II] as a charge transfer agent has high photosensitivity particularly to a semiconductor laser wavelength region, and has excellent chargeability. It has excellent durability due to little light fatigue even when used repeatedly, and is particularly useful as a high-speed, high-quality photoconductor for a printer.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an infrared absorption spectrum diagram of a titanyl phthalocyanine composition used in one embodiment of the present invention, and FIGS. 2 and 3 are known red titanyl phthalocyanine obtained by a conventional example. FIGS. 4 to 6 are X-ray diffraction diagrams of the titanyl phthalocyanine composition used in one example of the present invention, and FIG. 7 is a spectral sensitivity characteristic diagram of one example of the present invention.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-1-123868 (JP, A) JP-A-1-144468 (JP, A) JP-A-2-70763 (JP, A) JP-A-1- 142659 (JP, A) JP-A-2-27267 (JP, A) JP-A-3-9962 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03G 5 / 00-5 / 16

Claims (4)

(57) [Claims] 1. An electrophotographic photoreceptor containing a charge generator and a charge transfer agent, wherein (a) the charge generator is a metal-free phthalocyanine nitrogen isoform, a metal phthalocyanine nitrogen isoform, a metal-free phthalocyanine, a metal phthalocyanine, a metal-free Naphthalocyanine or metal naphthalocyanine (however, metal-free phthalocyanine nitrogen isoform, metal phthalocyanine nitrogen isoform, metal-free phthalocyanine and metal phthalocyanine may have a substituent on the benzene nucleus, and metal-free naphthalocyanine and metal naphthalocyanine Phthalocyanine may have a substituent on the naphthyl nucleus), and a total of 50 parts by weight or less of a titanyl phthalocyanine composition crystal containing 100 parts by weight of titanyl phthalocyanine as an active ingredient; The composition crystal has an infrared absorption spectrum of 14
90 ± 2cm ^-1 , 1415 ± 2cm ^-1 , 1332 ± 2cm ^-1 , 1119 ± 2cm ^-1 ,
1072 ± 2cm- ¹ , 1060 ± 2cm- ¹ , 961 ± 2cm- ¹ , 893 ± 2cm- ¹ ,
It has strong absorption characteristic at 780 ± 2 cm ⁻¹ , 751 ± 2 cm ⁻¹ and 730 ± 2 cm ⁻¹ , and has a Bragg angle (2θ ± 0.2 degrees) of 27.3 in an X-ray diffraction spectrum using CuK as a source. Shows a maximum diffraction peak at 9.7 degrees and 24.1 degrees, or shows a Bragg angle (2θ ± 0.2 degrees) of 27.3 in an X-ray diffraction spectrum using CuK as a source.
Degree of maximum diffraction peak at 7.4 °, 22.3 °, 24.1 °
, 25.3 degrees, and 28.5 degrees, and (b) a charge transfer agent represented by the general formula [I]; (Wherein R ¹ is a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxyl group, a halogen,
A carbazono group may be formed together with a substituted or unsubstituted amino group, morphforno group, piperidino group or phenyl group, R ² represents a hydrogen atom, a substituted or unsubstituted alkyl group, and R ³ and R ⁴ represent a hydrogen atom A substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a ring such as a pyridyl group, a pyridino group, a carbazono group, etc.), and a general formula [II]; (Where A is an electron donating group, R ⁵ is a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxyl group, and R ⁶ and R ⁷ are the same or different and are each a hydrogen atom, substituted or unsubstituted A substituted alkyl group, a substituted or unsubstituted aralkyl group, or a substituted or unsubstituted aryl group) as the active ingredient. 2. The electrophotographic photoreceptor according to claim 1, wherein a hydrazone compound is represented by the formula [III] as the charge transfer agent. 3. The charge transfer agent of the formula [II]
The electrophotographic photoreceptor according to claim 1, wherein R ⁶ or R ⁷ contains a compound having a substituted or unsubstituted aryl group. 4. A charge-transfer agent according to the general formula [II]
4. The electrophotographic photoreceptor according to claim 1, wherein R ⁵ contains a compound wherein A is a methyl group and A is a dialkylamino group.