JP2001060009A - Coating fluid for producing electrophotographic photoreceptor and electrophotographic photoreceptor using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a coating fluid excellent in coating property and having good stability while retaining the crystal forms of a phthalocyanine composition by dispersing a phthalocyanine composition containing TiOPc and H2Pc in a solvent together with a styrene-butadiene copolymer resin. SOLUTION: The phthalocyanine composition containing TiOPc and H2Pc is dispersed in a solvent together with a styrene-butadiene copolymer resin to produce the objective coating fluid. The phthalocyanine composition may further contain a phthalocyanine other than TiOPc and H2Pc and has peaks at 7.0 deg., 9.0 deg., 14.1 deg., 18.0 deg., 23.7 deg. and 27.3 deg. Bragg angles (2θ±0.2 deg.) to CuKα X-rays of 1.541 Å.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating liquid for producing an electrophotographic photosensitive member having excellent coatability and good stability, and an electrophotographic photosensitive member using this coating liquid which has high sensitivity and excellent repetition characteristics. It is about.

[0002]

2. Description of the Related Art In recent years, the use of electrophotography is not limited to the field of copying machines, but has spread to fields in which photographic technology has been conventionally used, such as printing plates, slide films, and microfilms. Also, application to a high-speed printer using a CRT as a light source is being studied. Recently, the use of a photoconductive material other than an electrophotographic photosensitive member, for example, an application to an electrostatic recording element, a sensor material, an EL element, and the like has been studied. Accordingly, demands for photoconductive materials and electrophotographic photoreceptors using the same are becoming higher and wider. Heretofore, inorganic photoconductive materials such as selenium, cadmium sulfide, zinc oxide, and silicon have been known as electrophotographic photoconductors, and have been widely studied and put to practical use. While these inorganic materials have many advantages, they also have various disadvantages. For example, selenium has drawbacks in that the production conditions are difficult and it is easy to crystallize due to heat and mechanical shock, and cadmium sulfide and zinc oxide have poor moisture resistance and durability. It has been pointed out that silicon is insufficient in chargeability and difficult to manufacture. further,
Selenium and cadmium sulfide also have toxicity problems.

On the other hand, organic photoconductive materials have good film-forming properties, excellent flexibility, are lightweight, have good transparency, and are sensitive to a wide wavelength range by an appropriate sensitization method. Due to its advantages such as easy design of the body, its practical use has been gradually attracting attention.

Incidentally, a photoreceptor used in the electrophotographic technology is generally required to have the following basic properties. That is, (1) high chargeability against corona discharge in a dark place, (2) little leakage (dark decay) of the obtained charge in a dark place, and (3) charge charge by light irradiation. (4) The residual charge after light irradiation is small.

However, many studies have been made on photoconductive polymers such as polyvinyl carbazole as organic photoconductive substances to date, but these have not always had sufficient film-forming properties, flexibility and adhesiveness. Also, it is difficult to say that the above-mentioned basic properties of the photoreceptor are sufficiently provided.

On the other hand, as for the organic low-molecular-weight photoconductive compound, by selecting a binder or the like used for forming the photoreceptor, the photoreceptor having excellent mechanical strength such as film property, adhesiveness and flexibility can be obtained. Can be obtained, but it is difficult to find a compound suitable for maintaining high-sensitivity properties.

In order to improve such a point, an organic photoreceptor having a higher sensitivity characteristic has been developed in which the charge generation function and the charge transport function are shared by different substances. The feature of such a photoreceptor, which is called a function-separated type, is that a material suitable for each function can be selected from a wide range, and a photoreceptor having an arbitrary performance can be easily manufactured. Has been advanced.

[0008] Of these, the substances responsible for the charge generation function include phthalocyanine pigments, squarium dyes,
Various substances such as azo pigments and perylene pigments have been studied,
Among them, azo pigments can have various molecular structures,
Widely studied because high charge generation efficiency can be expected,
Practical use is also progressing. However, in this azo pigment, the relationship between the molecular structure and the charge generation efficiency has not been clarified yet. The fact is that we are searching for the optimal structure through extensive synthesis research, but it fully satisfies the basic properties and high durability requirements of the photoreceptors listed above. Things have not yet been obtained.

In recent years, laser beam printers and the like, which use laser light as a light source instead of conventional white light and have the advantages of high speed, high image quality and non-impact, have become widespread in conjunction with the progress of information processing systems. At the same time, there is a demand for the development of a material that can withstand the demand. In particular, among laser beams, semiconductor lasers that have recently been applied to compact discs, optical discs, etc., and have made remarkable technological progress,
It has been actively applied in the printer field as a compact and highly reliable light source material. In this case, since the wavelength of the light source is around 780 nm, development of a photoreceptor having high sensitivity to long wavelength light around 780 nm has been strongly desired. In particular, photoconductors using phthalocyanines having light absorption in the near infrared region have been actively developed.

Phthalocyanines not only have different absorption spectra and photoconductivity depending on the type of central metal, but also have different characteristics depending on the crystal form of the phthalocyanine having the same central metal. It has been reported that the photoreceptor has been selected.

The Bragg angle of the X-ray diffraction spectrum (2θ ±
(0.2 [deg.]) Is titanyloxyphthalocyanine (hereinafter abbreviated as "TiOPc") having a maximum peak at 27.2 [deg.], Since the crystal form is a metastable type, and therefore a dispersion for forming a photosensitive layer. When the compound is prepared, it tends to change to another more stable crystal form depending on the conditions such as mechanical grinding force and dispersion solvent. Therefore, the electrophotographic characteristics often deteriorate at the stage of preparing the dispersion. JP-A-62-2
The main reason that the electrophotographic properties required for TiOPc reported in JP-A-67094 and JP-A-64-17066 are not sufficiently satisfied is that the crystal form change during the preparation of the dispersion liquid is a major factor. .

An example of using a mixed crystal of two or more phthalocyanines or a simple mixture thereof as a charge generating material of an electrophotographic photoreceptor is disclosed in JP-A-1-142659.
Discloses an α-form TiOPc comprising α-form TiOPc and a metal-free phthalocyanine (hereinafter abbreviated as “H ₂ Pc”).
In JP-A-2-170166, the composition is a mixed crystal composed of two or more phthalocyanines having different central metals, and in JP-A-2-27267, TiOPc and H ₂ Pc are disclosed.
X-type H ₂ Pc composition comprising:
No. 3 discloses a mixed crystal of TiOPc and hydroxymetal phthalocyanine, and JP-A-8-67829 discloses a Bragg angle (2θ ± 0.2) in an X-ray diffraction spectrum.
°) is 6.8 °, 7.4 °, 15.0 °, 24.7 °,
T having main diffraction peaks at 26.2 ° and 27.2 °
A mixed crystal of iOPc and H ₂ Pc has been reported. However, they do not sufficiently satisfy the required high properties.

It is generally said that the more uniformly a phthalocyanine or other charge-generating substance is dispersed in a binder resin, the better the electrophotographic properties such as image characteristics are. Has been studied. For example, a method using a styrene-butadiene copolymer resin as a binder resin for a photosensitive layer containing a mixed pigment of phthalocyanine and trigonal selenium has been proposed in JP-A-3-225346. The dispersion stability of the coating liquid is insufficient, and the electrophotographic properties are hardly improved.

As described above, various improvements have been made in the production of electrophotographic photoreceptors, but the requirements for the basic properties and high durability required for the above-described photoreceptors are not sufficiently satisfied. At present, there is no satisfactory product yet.

[0015]

SUMMARY OF THE INVENTION The object of the present invention is to solve the problem of Ti
While maintaining the crystal form of the phthalocyanine composition containing OPc and H ₂ Pc, a coating liquid for producing an electrophotographic photoreceptor having excellent coating properties and good stability was produced. An object of the present invention is to provide an electrophotographic photosensitive member having excellent sensitivity and repetition characteristics.

[0016]

As a result of various studies to achieve the above object, the present inventors have found that a phthalocyanine composition containing TiOPc and H ₂ Pc is converted into styrene-
It has been found that it is effective to produce a coating liquid for producing an electrophotographic photosensitive member by dispersing in a solvent together with a butadiene copolymer resin, and the present invention has been accomplished.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The electrophotographic photoreceptor of the present invention can use any of them. For example, there is one in which a photosensitive layer made of a charge generating substance, a charge transporting substance, and a film-forming binder resin is provided on a conductive support. Further, a laminated photoreceptor in which a charge generation layer composed of a charge generation substance and a binder resin and a charge transport layer composed of a charge transport substance and a binder resin are provided on a conductive support is also known. . Either of the charge generation layer and the charge transport layer may be an upper layer. In addition, if necessary, an undercoat layer is provided between the conductive support and the photosensitive layer, an overcoat layer is provided on the surface of the photosensitive member, and in the case of a laminated photosensitive member, an intermediate layer is provided between the charge generation layer and the charge transport layer. Can also be provided.

Hereinafter, each component of the present invention will be described in detail.

As the conductive support according to the present invention, various supports such as those used in known electrophotographic photosensitive members can be used. Specifically, for example, gold, silver, platinum, titanium, aluminum, copper, zinc, iron, conductive metal oxides such as drums, sheets, belts, or laminates of these thin films, deposits and the like Can be

Further, a conductive material such as metal powder, metal oxide, carbon black, carbon fiber, copper iodide, charge transfer complex, inorganic salt, and ionic conductive polymer electrolyte is coated with a suitable binder to form a polymer matrix. Plastics and ceramics embedded inside and subjected to conductive treatment,
Drums, sheets, belts, and the like made of paper and the like, and drums, sheets, belts, and the like of plastics, ceramics, paper, and the like containing such a conductive substance and made conductive.

The phthalocyanines used in the present invention include:
Known production methods can be used. The production method is described in “Phthalocyanine Compou
nds "(1963) describes a production method, and according to this method, phthalocyanines can be easily obtained. TiOPc
For example, a production method by a condensation reaction of phthalodinitrile and titanium tetrachloride, or PB85172. FI
AT. FINAL REPORT 1313. Feb.
1.1948, JP-A-1-142658, and JP-A-1-221461, for example, a method of producing by a reaction between 1,3-diiminoisoindoline and tetraalkoxytitanium. Examples of the organic solvent used in the reaction include α-chloronaphthalene, β-chloronaphthalene, α-methylnaphthalene, methoxynaphthalene, diphenylnaphthalene, ethylene glycol dialkyl ether, quinoline, sulfolane, dichlorobenzene, and N-methyl-2-pyrrolidone. And a reaction-inactive high-boiling solvent such as dichlorotoluene.

The phthalocyanines obtained by the above-mentioned method are converted to acids, alkalis, acetone, methanol, ethanol, methyl ethyl ketone, tetrahydrofuran, pyridine, quinoline, sulfolane, α-chloronaphthalene, toluene, xylene, 1,4-dioxane, chloroform, By purifying with 1,2-dichloroethane, N, N-dimethylformamide, N-methyl-2-pyrrolidone, water or the like, high-purity phthalocyanines usable for electrophotography can be obtained. Examples of the purification method include a washing method, a recrystallization method, an extraction method such as Soxhlet, a hot suspension method, and a sublimation method. The purification method is not limited to these, and any method may be used as long as it removes unreacted substances and reaction by-products.

The phthalocyanine composition according to the present invention has T
It contains iOPc and H ₂ Pc, but TiOPc and H ₂
Phthalocyanines other than Pc may be further contained. The phthalocyanines which may be contained may be any of phthalocyanines and derivatives thereof known per se.
Derivatives include those having a substituent on the isoindole ring of phthalocyanine and those having a ligand on the central metal. Specific examples of phthalocyanines that may be contained are vanadyl phthalocyanines, copper phthalocyanines, aluminum phthalocyanines, gallium phthalocyanines, indium phthalocyanines,
Germanium phthalocyanines, lithium phthalocyanines, sodium phthalocyanines, potassium phthalocyanines, zirconium phthalocyanines, hafnium phthalocyanines, magnesium phthalocyanines, tin phthalocyanines, zinc phthalocyanines, cobalt phthalocyanines, nickel phthalocyanines, barium phthalocyanines, beryllium phthalocyanines , Cadmium phthalocyanines, cobalt phthalocyanines,
Examples include iron phthalocyanines, silicon phthalocyanines, lead phthalocyanines, silver phthalocyanines, gold phthalocyanines, platinum phthalocyanines, ruthenium phthalocyanines, palladium phthalocyanines, metal-free naphthalocyanines, titanyl naphthalocyanines, and the like. Of these, vanadyloxyphthalocyanine, chloroaluminum phthalocyanine, chlorogallium phthalocyanine, chloroindium phthalocyanine, dichlorogermanium phthalocyanine, hydroxyaluminum phthalocyanine, hydroxygallium phthalocyanine, hydroxyindium phthalocyanine, and dihydroxygermanium phthalocyanine are particularly preferred.

The ratio of TiOPc to phthalocyanines other than TiOPc in the phthalocyanine composition according to the present invention is based on 100 parts by weight of TiOPc and TiOPc.
Other phthalocyanines are preferably 0.1 to 50 parts by weight, more preferably 1 to 40 parts by weight. The phthalocyanines other than TiOPc may be H ₂ Pc alone or a mixture of the phthalocyanines and H ₂ Pc shown above.
The mixing ratio is preferably 100 parts by weight or less, more preferably 50 parts by weight or less, based on 100 parts by weight of H ₂ Pc.

The method for amorphizing the amorphous phthalocyanine composition, amorphous TiOPc or amorphous H ₂ Pc used in the present invention may be any method that can be made amorphous, such as mechanical grinding or acid pasting. Any one may be used. Examples of the mechanical grinding include a dry milling method using a ball mill, an automatic mortar, a paint conditioner, and the like. Milling aids include, but are not limited to, glass beads, zirconia beads, salt, and the like. The acid pasting method is a method in which phthalocyanines are dissolved in a strong acid such as sulfuric acid, and the solution is poured into a poor solvent such as water to form particles.
In addition, any phthalocyanine crystal form before being made amorphous may be used.

Specific examples of the aromatic compound required for the crystal transition to the phthalocyanine composition according to the present invention include aromatic hydrocarbon compounds such as benzene, toluene, naphthalene, m-terphenyl and cumene, and chlorobenzene. And bromobenzene and o-dichlorobenzene, and aromatic heterocyclic compounds such as benzothiophene, benzofuran and N-ethylcarbazole. These aromatic compounds may be in a liquid state or a solid state at room temperature, but have a melting point of 10
It is preferably 0 ° C. or lower. These can be used alone or as a mixture of two or more.

The aromatic compound can be combined with various organic solvents. Specific examples of the organic solvent that can be combined include alcohol solvents such as methanol, ethanol, and isopropyl alcohol; ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; ethyl formate, ethyl acetate, and n-butyl acetate. Ester solvents such as
Ether solvents such as diethyl ether, dimethoxyethane, tetrahydrofuran, 1,3-dioxolan or 1,4-dioxane, N, N-dimethylformamide, N, N-dimethylacetamide, and N-methyl-2-pyrrolidone; Amide solvents, dichloromethane, chloroform, bromoform, methyl iodide, 1,
Halogenated aliphatic hydrocarbon solvents such as 2-dichloroethane, trichloroethane, or trichloroethylene;
n-pentane, n-hexane, n-octane, 1,5-
Examples thereof include aliphatic hydrocarbon solvents such as hexadiene, cyclohexane, methylcyclohexane, cyclohexadiene and terpinolene. These can be used alone or as a mixed solvent of two or more.

The ratio of phthalocyanine to water at the time of crystal transition to the phthalocyanine composition is as follows.
Water is preferably 2 to 100 parts by weight with respect to parts by weight, but is not limited to this range as long as the phthalocyanines can be dispersed. Similarly, the ratio of the phthalocyanine to the aromatic compound is preferably 10 to 5,000 parts by weight of the aromatic compound with respect to 100 parts by weight of the phthalocyanine,
50 to 500 parts by weight is more preferred. When the crystal transition is carried out using an aromatic compound and an organic solvent in combination, the ratio of the aromatic compound to the organic solvent is preferably 1,000 parts by weight or less, more preferably 200 parts by weight or less with respect to 100 parts by weight of the aromatic compound. Is more preferred.

The transition temperature is preferably 80 ° C. or higher, and more preferably the stirring is performed. Examples of the method of stirring include a stirrer, a ball mill, a paint conditioner, a sand mill, an attritor, a disperser, and an ultrasonic dispersion. However, any method can be used as long as stirring can be performed, and the method is not limited thereto. The time required for the transfer is preferably 5 seconds to 120 hours, more preferably 10 seconds to 50 hours, and even more preferably 1 minute to 50 hours.

In some cases, a surfactant may be added. The surfactant may be any of a cationic type, a nonionic type and an anionic type. The amount of addition is 0.0 to 100 parts by weight of the phthalocyanine composition.
It is preferably from 0.01 to 50 parts by weight, more preferably from 0.5 to 5 parts by weight.

In the present invention, a styrene-butadiene copolymer resin is used as a film-forming binder resin which is a binder used to form a photosensitive layer. By using this resin, it is possible to obtain a dispersion having good stability while maintaining the crystal form of the phthalocyanine composition containing TiOPc and H ₂ Pc, and the coating property of the dispersion is also good. Become. Further, by preparing an electrophotographic photoreceptor using the dispersion, the chargeability, sensitivity and repetition characteristics are improved.

The styrene content of the styrene-butadiene copolymer resin used in the present invention is preferably 50 to 95% by weight, particularly preferably 70 to 95% by weight. Further, the glass transition point is preferably from 30 to 60 ° C, particularly preferably from 40 to 50 ° C.

Examples of commercially available styrene-butadiene copolymer resins used in the present invention include GOODYEAR's
Pliolite S-5 series. Pliolite S-5
The series has excellent chemical resistance, polar solvent resistance, and pigment binding properties, and is optimal as a binder for dispersing phthalocyanines.

The styrene-butadiene copolymer resin according to the present invention may be used in combination with other resins. Examples of the resin that may be used include a silicone resin, a phenoxy resin, a butyral resin, a phenol resin, an epoxy resin, a polycarbonate, a polyarylate, a polyester, a polyamide, a polyimide, a urethane resin, an acrylic resin, and a vinyl chloride resin. These resins can be used alone or in combination of two or more.

These resins contained in the photosensitive layer are 10 to 500 parts by weight based on 100 parts by weight of the phthalocyanine composition.
Part by weight is preferable, and 50 to 150 parts by weight is more preferable. If the ratio of the resin is too high, the charge generation efficiency is lowered, and if the ratio of the resin is too low, there is a problem in film formability.

In the present invention, when the photosensitive layer contains a charge transport material, the charge transport material used includes a hole transport material and an electron transport material. Examples of the hole transfer material include oxadiazoles disclosed in JP-B-34-5466, triphenylmethanes disclosed in JP-B-45-555, and JP-B-52-4188. Pyrazolines described in gazettes and the like, JP-B-55-423
Hydrazones disclosed in JP-A-80-80, etc .;
Oxadiazoles described in JP-A-123544, etc., triarylamines described in JP-B-58-32372, etc., stilbenes described in JP-A-58-198043, etc. Is mentioned. On the other hand, examples of electron transfer materials include chloranil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,4
7-trinitro-9-fluorenone, 2,4,5,7-
Tetranitro-9-fluorenone, 2,4,5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 1,3,7-trinitrodibenzothiophene, 1,3,7-trinitrodibenzothiophene- 5,
5-dioxide and the like. These charge transport materials can be used alone or in combination of two or more.

Among these charge transport materials, hydrazones and stilbenes are preferable because they have high charge (hole) mobility and provide excellent electrophotographic photosensitive members. Among the hydrazones, JP-A-1-100555, JP-A-2-10367, JP-A-2-51163, and JP-A-2-51163
JP-A-96767, JP-A-2-183260, and JP-A-2-183260
JP-A-184856, JP-A-2-184858, JP-A-2-184859, JP-A-2-226160,
The hydrazone compounds described in JP-A-5-188609 and JP-A-7-140686 are particularly preferred. Also, among the stilbenes, JP-A-2-51162, JP-A-2-184857, JP-A-3-75660, JP-A-4-177358, JP-A-6-1948551,
The stilbene compounds described in JP-A Nos. 7-120945, 7-140683, 10-78671, and 10-90923 are particularly preferable.

Further, a certain kind of electron-withdrawing compound can be added as a sensitizer for further enhancing the sensitizing effect. Examples of the electron-withdrawing compound include 2,3-
Dichloro-1,4-naphthoquinone, 1-nitroanthraquinone, 1-chloro-5-nitroanthraquinone, 2-
Chloroanthraquinone, quinones such as phenanthrenequinone, aldehydes such as 4-nitrobenzaldehyde,
9-benzoylanthracene, indandione, 3,5
-Dinitrobenzophenone, or 3,3 ', 5
Ketones such as 5'-tetranitrobenzophenone, acid anhydrides such as phthalic anhydride and 4-chloronaphthalic anhydride;
Cyano compounds such as terephthalalmalononitrile, 9-anthrylmethylidenemalononitrile, 4-nitrobenzalmalononitrile, or 4- (p-nitrobenzoyloxy) benzalmalononitrile, 3-benzalphthalide, 3- (α- Phthalides such as cyano-p-nitrobenzal) phthalide and 3- (α-cyano-p-nitrobenzal) -4,5,6,7-tetrachlorophthalide can be mentioned.

In the laminated type photoreceptor, the charge transport layer is constituted by at least a mixture of the charge transport material and the binder. As the binder used for the charge transport layer, polystyrene, an acrylic resin represented by polymethyl methacrylate, polycarbonate having a skeleton represented by bisphenol A or Z, polyarylate, polyester,
Polyphenylene ether, polyether sulfone, polyamide, polyimide, and the like can be used. These resins can be used alone or in combination of two or more.

The amount of the binder contained in the charge transporting layer is preferably from 0.1 part by weight to 2000 parts by weight, more preferably from 1 part by weight to 100 parts by weight of the charge transporting substance.
500 parts by weight or less is more preferable. If the ratio of the binder is too high, the sensitivity is lowered, and if the ratio of the binder is too low, the repetition characteristics may be deteriorated or the coating may be damaged.

The electrophotographic photoreceptor of the present invention contains 2,6-
It is preferable to add an antioxidant such as di-tert-butyl-p-cresol or DL-α-tocopherol to the photosensitive layer. By adding these antioxidants,
An electrophotographic photoreceptor having excellent repetition characteristics can be obtained.

The coating liquid for producing an electrophotographic photoreceptor of the present invention contains at least the phthalocyanine composition and a styrene-butadiene copolymer resin, and is prepared by dispersing the phthalocyanine composition together with a styrene-butadiene copolymer resin in a solvent. can get. An apparatus used for dispersing the phthalocyanine composition is a dispersing machine using a dispersing medium such as a ball mill, a paint conditioner, a dyno mill, and an attritor. As the material of the dispersion medium, soda glass, low alkali glass, and zirconia containing yttria are preferable, and beads having a diameter of several mm are often used. According to the production method of the present invention, a coating liquid for producing an electrophotographic photoreceptor having good dispersibility and excellent coatability can be obtained without changing the crystal form of the phthalocyanine composition.

The coating liquid thus prepared is spin-coated,
An electrophotographic photosensitive member is obtained by coating and drying on a conductive support by a known method such as blade coating, knife coating, reverse roll coating, rod bar coating, and spray coating.
In particular, when coating on a drum, a dipping (dip) coating method or the like is used.

In the electrophotographic photoreceptor of the present invention, the phthalocyanine composition is dispersed in a solvent, and the binder and the charge transporting substance are dissolved in the solvent before use. Examples of the solvent to be used include water and an organic solvent, and they are used alone or as a mixed solvent of two or more kinds. The water may be heavy water or a mixture of water and heavy water. As the organic solvent, methanol, ethanol, alcohol solvents such as isopropyl alcohol, acetone,
Ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, ester solvents such as ethyl formate, ethyl acetate and n-butyl acetate, diethyl ether, 1,2-dimethoxyethane, tetrahydrofuran, 1,3-dioxolan, 1,4-dioxane , Anisole and other ether solvents, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone and other amide solvents, dichloromethane, chloroform, bromoform, methyl iodide, dichloroethane, trichloroethane, trichloroethylene Chlorobenzene, o-dichlorobenzene, fluorobenzene, bromobenzene, iodobenzene, halogenated hydrocarbon solvents such as α-chloronaphthalene, n-pentane, n-hexane, n-octane, 1,5-hexadiene Down, cyclohexane, methylcyclohexane, cyclohexadiene, benzene, toluene, o- xylene, m- xylene, p- xylene, ethylbenzene, may be mentioned hydrocarbon solvents such as cumene. Particularly, among them, ketone solvents, ester solvents and ether solvents are preferable.

[0045]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Synthesis Example 1 20.0 g of phthalodinitrile was converted to α-chloronaphthalene 2
In a nitrogen atmosphere under a nitrogen atmosphere.
g was added dropwise. After completion of the dropwise addition, the mixture was heated and stirred at 240 ° C.
After 3 hours, the reaction was stopped, and the precipitated crystals were collected by filtration and washed well with α-chloronaphthalene and methanol to obtain dichlorotitanyl phthalocyanine. This dichlorotitanyl phthalocyanine was heated and refluxed with stirring with 150 ml of concentrated aqueous ammonia. After 1 hour, the reaction was stopped, and the crystals were collected by filtration to obtain 17.4 g of TiOPc.

Synthesis Example 2 7.0 g of TiOPc obtained in Synthesis Example 1 and 3.0 g of H ₂ Pc (manufactured by Dainichi Seika; MCP-80) were slowly added to 100 ml of concentrated sulfuric acid cooled to about 2 ° C. and dissolved. I let it. The solution was slowly poured into 1000 ml of cooled ice water to precipitate crystals. The crystals were collected by filtration and washed with water until neutral to obtain 9.4 g of crystals. This crystal was in an amorphous state with disordered crystal arrangement.

Synthesis Example 3 7.0 g of TiOPc obtained in Synthesis Example 1, H ₂ Pc3.
Acid pasting treatment was performed in the same manner as in Synthesis Example 2 except that 0 g was changed to only 10.0 g of TiOPc obtained in Synthesis Example 1. As a result, 9.3 g of crystals were obtained. This crystal was in an amorphous state with disordered crystal arrangement.

Synthesis Example 4 7.0 g of TiOPc obtained in Synthesis Example 1, H ₂ Pc3.
Acid pasting treatment was performed in the same manner as in Synthesis Example 2 except that 0 g was changed to only 10.0 g of H ₂ Pc. As a result, 9.5 g of crystals were obtained. This crystal was in an amorphous state with disordered crystal arrangement.

Synthesis Example 5 1.0 g of the amorphous phthalocyanine composition obtained in Synthesis Example 2 and 28.0 g of water were placed in a 100 ml flask.
The mixture was heated and stirred at 90 ° C. 10 minutes later, 2.0 g of naphthalene
Was added thereto, followed by heating and stirring at the same temperature. One hour later, the reaction was stopped, and the mixture was allowed to cool to room temperature. The crystals were collected by filtration and washed with methanol. As a result, 0.9 g of a crystal was obtained.
The obtained crystal form was confirmed by measuring an X-ray diffraction spectrum using CuKα ray (X-ray diffractometer RAD-C system manufactured by Rigaku Corporation). FIG. 1 shows the measurement results.

Measurement conditions X-ray tube: Cu Voltage: 40.0 KV Current: 100.0 mA Start angle: 3.0 deg. Stop angle: 40.0 deg. Step angle: 0.02 deg.

FIG. 1 shows that this crystal form has a Bragg angle (2θ
± 0.2 °) is 7.0 °, 9.0 °, 14.1 °, 1
It can be seen that there are peaks at 8.0 °, 23.7 °, and 27.3 °.

Synthesis Example 6 Crystal transition was carried out in the same manner as in Synthesis Example 5 except that 2.0 g of naphthalene was changed to 1.0 g of naphthalene and 1.0 g of ethylcyclohexane. As a result, 0.9 g of a crystal was obtained. The X-ray diffraction spectrum of this crystal was similar to that of FIG.

Synthesis Example 7 1.0 g of the amorphous phthalocyanine composition obtained in Synthesis Example 2 was replaced with the amorphous TiOPc obtained in Synthesis Example 3.
0.7 g of the amorphous H ₂ Pc0.
Crystal transition was carried out in the same manner as in Synthesis Example 5 except that the mixture was changed to 3 g of the mixture. As a result, 0.9 g of a crystal was obtained. The X-ray diffraction spectrum of this crystal was similar to that of FIG.

Synthesis Example 8 Crystal transition was carried out in the same manner as in Synthesis Example 5 except that 2.0 g of naphthalene was changed to 2.0 g of n-octane. As a result, 0.9 g of a crystal was obtained. The X-ray diffraction spectrum of this crystal is shown in FIG. FIG. 2 shows that this crystal form has peaks at Bragg angles (2θ ± 0.2 °) of 7.4 ° and 27.2 °, but the peak intensity is low as a whole.

Comparative Synthesis Example 1 7.0 g of TiOPc obtained in Synthesis Example 1 and H ₂ Pc3.
0 g of copper phthalocyanine (Tokyo Kasei; P-100
6) An acid pasting treatment was performed in the same manner as in Synthesis Example 2 except that the amount was changed to only 10.0 g. As a result, 9.4 g of crystals were obtained. This crystal was in an amorphous state with disordered crystal arrangement.

Comparative Synthetic Example 2 1.0 g of the amorphous phthalocyanine composition obtained in Synthetic Example 2 was replaced with the amorphous TiOPc obtained in Synthetic Example 3.
Crystal transition was carried out in the same manner as in Synthesis Example 5 except that the mixture was changed to a mixture of 0.7 g and 0.3 g of the amorphous copper phthalocyanine obtained in Comparative Synthesis Example 3. As a result, 0.9 g of a crystal was obtained. FIG. 3 shows the X-ray diffraction spectrum of this crystal. From FIG. 3, this crystal form has a Bragg angle (2θ ± 0.
2 °) is 7.0 °, 9.2 °, 14.3 °, 18.1
°, 18.5 °, 23.7 °, 24.0 °, 27.2 °
It can be seen that there is a peak at

Example 1 10 parts by weight of the phthalocyanine composition obtained in Synthesis Example 5, a styrene-butadiene copolymer resin (manufactured by GOODYEAR; Pl
10 parts by weight of iolite S-5D) was mixed with 1000 parts by weight of ethyl acetate, and dispersed for 1 hour together with glass beads having a diameter of 1 mm by a paint conditioner manufactured by Red Devil. The resulting dispersion was applied on an aluminum-evaporated polyester with an applicator and dried to a film thickness of about 0.2.
A μm charge generation layer was formed.

Next, 100 parts by weight of the stilbene compound represented by (1), 100 parts by weight of a polycarbonate resin (manufactured by Mitsubishi Gas Chemical; Z-400), and 1 part by weight of DL-α-tocopherol (E1000, manufactured by Riken Vitamin) were added. Was dissolved in 2000 parts by weight of tetrahydrofuran, and this solution was applied on the charge generation layer with an applicator and dried to form a charge transport layer having a dry film thickness of 25 μm.

[0060]

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The electrophotographic photoreceptor thus prepared is stored in a dark room at room temperature for 24 hours, then pasted on a drum-shaped aluminum tube, mounted on a commercial office copying machine, and formed with an image.
The image was investigated for any failures. The appearance of the obtained copied image is given in Table 1. Further, using an electrostatic recording tester (Kawaguchi Electric Works; EPA-8200), the photosensitive member was
After being charged at a charging voltage of 5.0 kV, the photosensitive member was irradiated with 2 lux of tungsten light to measure the half-life exposure amount E _1/2 of the photosensitive member. The results are given in Table 2.

Next, the electrophotographic photosensitive member was affixed to an aluminum drum base tube, and a process speed of 190 mm / sec and a charging voltage of -7. 0 kV, exposure light wavelength 7
Under the conditions of 80 nm and exposure light intensity of ² μW / cm ² ,
Exposure and static elimination were repeated 10,000 times, and before and after that, the charged potential and residual potential of the photoreceptor were measured. Table 2 shows the results.

Example 2 Styrene-butadiene copolymer resin (GOODYEAR)
Ex. Pliolite S-5D) was changed to a styrene-butadiene copolymer resin (manufactured by Nippon Synthetic Rubber; JSR0602), a photoconductor was produced in the same manner as in Example 1, and the same measurement as in Example 1 was performed. The results are shown in Tables 1 and 2.

Example 3 Styrene-butadiene copolymer resin (GOODYEAR)
10% by weight of a styrene-butadiene copolymer resin (manufactured by GOODYEAR; Pliolite S-5).
D) 8 parts by weight, acrylic resin (manufactured by Mitsubishi Rayon; BR-
52) A photoconductor was prepared in the same manner as in Example 1 except that the amount was changed to 2 parts by weight, and the same measurement as in Example 1 was performed. The results are shown in Tables 1 and 2.

Example 4 Styrene-butadiene copolymer resin (GOODYEAR)
10% by weight of a styrene-butadiene copolymer resin (manufactured by GOODYEAR; Pliolite S-5).
D) 8 parts by weight, butyral resin (manufactured by Sekisui Chemical; BM-
1) A photoconductor was prepared in the same manner as in Example 1 except that the amount was changed to 2 parts by weight, and the same measurement as in Example 1 was performed. The results are shown in Tables 1 and 2.

Comparative Examples 1 to 6 Styrene-butadiene copolymer resin (GOODYEAR)
Pliolite S-5D), a polycarbonate resin (manufactured by Teijin; TS-2020), a polyester resin (manufactured by Toyobo; V-220), a styrene resin (manufactured by Mitsubishi Monsanto; DL-HH-102), and styrene-maleic anhydride. Polymerized resin (manufactured by Seiko Chemical; X-220), styrene-acrylonitrile copolymer resin (manufactured by Asahi Dow; Tyryl 783)
A), vinyl toluene-butadiene copolymer resin (GOO
A photoreceptor was prepared in the same manner as in Example 1 except for changing to Pliolite VT (manufactured by DYEAR; Pliolite VT), and the same measurement as in Example 1 was performed. The results are shown in Tables 1 and 2.

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[Table 1]

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[Table 2]

In Comparative Examples 3 and 4, coating was not possible because the dispersibility of the dispersions prepared from the phthalocyanine compositions was very poor. In Comparative Examples 5 and 6, the dispersions prepared from the phthalocyanine compositions had poor dispersibility, and unevenness and streaks occurred on the application surface of the charge generation layer. Further, when the electrophotographic photosensitive member was mounted on a copying machine and an image was formed, an image failure such as a pinhole as well as density unevenness was observed. In Comparative Examples 1 and 2, both the dispersibility and the applicability of the dispersion prepared from the phthalocyanine composition were good, but the sensitivity of the electrophotographic photoreceptor was very poor.
When mounted on a copier to form an image, image failure such as fogging was observed. In contrast, in Examples 1 to 4, the dispersion prepared from the phthalocyanine composition had good dispersibility and applicability, the electrophotographic photoreceptor had high sensitivity, and had good repetition characteristics. No image failure was observed at the time of forming.

Example 5 Alcohol-soluble nylon (manufactured by Toray; CM-8000)
5 parts by weight are dissolved in 100 parts by weight of methanol, 5 parts by weight of titanium oxide (rutile type, manufactured by Sakai Chemical; R-310) are mixed, and the mixture is mixed with zirconia beads having a diameter of 1 mm by a paint conditioner manufactured by Red Devil for 5 hours. Dispersed. The titanium oxide dispersion thus obtained is applied to an aluminum sheet (JIS standard # 105) using an applicator.
0) Coating on top and drying to form an undercoat layer with a thickness of 0.5 μm.

Next, 1 part by weight of the phthalocyanine composition obtained in Synthesis Example 5 was mixed with a styrene-butadiene copolymer resin (GOO).
DYEAR; Pliolite S-5D) (1 part by weight) was mixed with methyl ethyl ketone (100 parts by weight) and dispersed for 1 hour together with glass beads having a diameter of 1 mm by a paint conditioner manufactured by Red Devil. The resulting dispersion was applied on the undercoat layer with an applicator and dried to form a charge generation layer having a thickness of about 0.4 μm.

Next, 100 parts by weight of a hydrazone compound represented by (2), 100 parts by weight of a polycarbonate resin (manufactured by Teijin Chemicals Ltd .; Panlite K-1300), 2,6-di-t
1 part by weight of tert-butyl-p-cresol was dissolved in 2000 parts by weight of dichloromethane, and this solution was applied on the charge generation layer with an applicator and dried to form a charge transport layer having a dry film thickness of 30 μm. .

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The electrophotographic photoreceptor thus produced was stored in a dark place at room temperature for 24 hours, and the same measurement as in Example 1 was performed. The results are shown in Tables 3 and 4.

Examples 6 to 8 Photoconductors were prepared in the same manner as in Example 5, except that the phthalocyanine compositions obtained in Synthesis Example 5 were changed to the phthalocyanine compositions obtained in Synthesis Examples 6, 7, and 8, respectively. Was prepared, and the same measurement as in Example 1 was performed. The results are shown in Tables 3 and 4.

Comparative Examples 7 to 10 The phthalocyanine composition obtained in Synthesis Example 5 was replaced with the phthalocyanine composition obtained in Comparative Synthesis Example 2,
No. 2659, a TiOPc composition disclosed in
H ₂ Pc composition described in JP-272067, JP 6
A photoconductor was prepared in the same manner as in Example 5 except that TiOPc described in JP-A-4-17066 was used, and the same measurement as in Example 1 was performed. The results are shown in Tables 3 and 4.

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[Table 3]

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[Table 4]

In Comparative Example 10, although the dispersion prepared from the phthalocyanine composition was excellent in both dispersibility and coatability, the sensitivity of the electrophotographic photosensitive member was extremely poor. At the time, image failure such as fogging was observed. In Comparative Examples 7 to 9, the dispersibility of the dispersions prepared from the phthalocyanine compositions was poor, and unevenness and streaks occurred on the application surface of the charge generation layer. Further, when the electrophotographic photosensitive member was mounted on a copying machine and an image was formed, image defects such as pinholes as well as density unevenness were observed. In contrast, in Examples 5 to 8, the dispersion prepared from the phthalocyanine composition had good dispersibility and applicability, the electrophotographic photoreceptor had high sensitivity, and had good repetition characteristics. Is formed, there is no problem at all, as little black spots can be seen. In particular, CuKα1.5
Bragg angle (2θ ± 0.41) for X-ray of 41 angstroms.
2 °) is 7.0 °, 9.0 °, 14.1 °, 18.0
In Examples 5 to 7 using the phthalocyanine compositions having peaks at 0 °, 23.7 ° and 27.3 °, the sensitivity and repetition characteristics of the electrophotographic photoreceptor are very excellent.
You can see from

[0080]

As is apparent from the above, according to the present invention, a coating liquid for producing an electrophotographic photosensitive member having good stability is produced while maintaining the crystal form of the phthalocyanine composition. Can be used to provide an electrophotographic photosensitive member having high sensitivity and excellent repetition characteristics.

[Brief description of the drawings]

FIG. 1 is an X-ray diffraction spectrum of the phthalocyanine composition obtained in Synthesis Example 5.

FIG. 2 is an X-ray diffraction spectrum of the phthalocyanine composition obtained in Synthesis Example 8.

FIG. 3 shows the X of the phthalocyanine composition obtained in Comparative Synthesis Example 2.
Line diffraction spectrum.

Claims (4)

[Claims] 1. A coating liquid for producing an electrophotographic photoreceptor obtained by dispersing a phthalocyanine composition containing titanyloxyphthalocyanine and a metal-free phthalocyanine in a solvent together with a styrene-butadiene copolymer resin. 2. The method according to claim 1, wherein the phthalocyanine composition is CuKα.
Bragg angle (2θ) for X-rays of 1.541 angstroms
The coating liquid for producing an electrophotographic photoreceptor according to claim 1, wherein (0.2 °) has a peak at 27.3 °. 3. The method according to claim 2, wherein the phthalocyanine composition is CuKα.
Bragg angle (2θ) for X-rays of 1.541 angstroms
± 0.2 °) is 7.0 °, 9.0 °, 14.1 °, 1
2. The coating liquid for producing an electrophotographic photosensitive member according to claim 1, wherein the coating liquid has peaks at 8.0, 23.7, and 27.3. 4. An electrophotographic photosensitive member having a photosensitive layer on a conductive support, wherein the photosensitive layer is at least one of claims 1 to 3.
An electrophotographic photosensitive member formed by using the coating liquid for producing an electrophotographic photosensitive member according to any one of the above.