JPH01230581A - Novel metal-free phtalocyanine compound, its production and electrophotographic photoreceptor using the same - Google Patents

Abstract

NEW MATERIAL:A nonmetal phtalocyanine having an X-ray diffraction pattern showing distinctive peaks at Bragg angle (2theta+ or -2 deg.), 6.7 deg., 7.3 deg., 13.5 deg., 14.9 deg., 15.9 deg., 16.7 deg., 24.7 deg. and 26.1 deg.. USE:Electrophotographic photoreceptor. It has excellent exposure sensitivity characteristics, wavelength characteristics, deterioration resistance in repetitive use for a long period of time, printing resistance and image stability. PREPARATION:A metal-free phtalocyanine which is prepared from a metal phtalocyanine by the acid pasting method is milled with mechanical stress at 30-220 deg.C, preferably at 60-130 deg.C to convert the crystal morphology.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention is a novel metal-free phthalocyanine compound.

The present invention relates to a manufacturing method thereof and an electrophotographic photoreceptor using the same.

(Conventional technology) Conventionally, selenium has been used as the photoreceptor for electrophotographic photoreceptors.

Inorganic photoconductors such as selenium alloys, zinc oxide, cadmium sulfide and tellurium have been used primarily. In recent years, the development of semiconductor lasers has been remarkable, and small and stable laser oscillators have become available at low cost and are beginning to be used as light sources for electrophotography. but,
Using semiconductor lasers that emit short-wavelength light in these devices has many problems in terms of lifespan, output, etc. Therefore, the conventionally used materials sensitive in the short wavelength region are unsuitable for use in semiconductor lasers, and the materials sensitive in the long wavelength region (
It has become necessary to research materials with high sensitivity to wavelengths of 780n+m or higher. Recently, organic materials, especially phthalocyanine, which is expected to have sensitivity in the long wavelength region, have been used.
Research into multilayer organic photoreceptors in which these materials are laminated is being actively conducted. For example, as a divalent phthalocyanine, ε
Type copper phthalocyanine (ε-CuPc), X-type metal-free phthalocyanine (X-H2Pc), and τ-type metal-free phthalocyanine (τ-H2Pc) have sensitivity in the long wavelength region. Trivalent and tetravalent metal phthalocyanines include chloroaluminum phthalocyanine (,6j2Pcc1), chloroaluminum phthalocyanine chloride (CIAIPcC
l), oxotitanium phthalocyanine (TiOPc)
or chloroindium phthalocyanine (InPcC1)
) is vapor-deposited and then brought into contact with the vapor of a soluble solvent to make it have a long wavelength and a high degree of anger (Japanese Unexamined Patent Publication No. 57-39484, JP-A No. 59-166959).
i.

A method of long-wavelength treatment of phthalocyanine containing Sn and Pb using various substituents, derivatives, or shifting agents such as crown ether (Japanese Patent Application No. 59-36254)
(Japanese Patent Application No. 59-204045), sensitivity is obtained in the long wavelength region.

However, until now, the current situation has been that satisfactory characteristics have not been obtained in electrophotographic photoreceptors at initial and repeated stages.

LEDs have also been put into practical use as digital light sources for printers. LEDs in the visible light range are also used, but those that are generally put into practical use have an oscillation wavelength of 650 r+m or more, typically 660 nm.

Azo compounds, perylene compounds, selenium, zinc oxide, etc.
Although it cannot be said that the phthalocyanine compound has sufficient photosensitivity at around 650 nm, it has an absorption peak around 650 nm, so it can be used as an effective material as a charge generating agent for LEDs.

(Problems to be Solved by the Invention) The purpose of the present invention is to provide excellent exposure sensitivity characteristics and wavelength characteristics, as well as deterioration resistance during repeated use over a long period of time.

The object of the present invention is to obtain an electrophotographic photoreceptor having rigidity resistance and image stability.

[Structure of the invention]

(Means and effects for solving the problems) The present invention has the following features:
Bragg angle (2θ±0.2') of 6.7° and 7.3°
, 13.5°, 14.9°, 15.9°, 16°7°,
It is a metal-free phthalocyanine compound with an X-ray diffraction diagram showing clear X-ray diffraction peaks at the positions of 24.7@ and 26.1°, and is produced by removing the metal from the metal phthalocyanine compound using the acid pasting method. of the metal-free phthalocyanine compound at 30 to 220°C, preferably 60 to 130°C.

In this method, the metal-free phthalocyanine compound is produced by milling with a mechanical strain force to convert the crystal, that is, milling with a mechanical strain force for a sufficient time and/or stirring to convert the crystal form. Furthermore, the present invention is an electrophotographic photoreceptor comprising a charge generating agent and a charge transfer agent on a conductive support, wherein the charge generating agent is the metal-free phthalocyanine compound described above.

In addition, 9 metal-free phthalocyanine compounds related to the present invention are:
It may have any substituent.

The metal-free phthalocyanine compound of the present invention is produced by the following method, but is not limited thereto.

Generally, phthalocyanine is produced using the phthalodinitrile method, which involves heating and melting phthalodinitrile and a metal chloride or by heating in the presence of an organic solvent, or by heating and melting phthalic anhydride with urea and a metal chloride or by heating in the presence of an organic solvent. Examples include, but are not limited to, the Weiler method, the method of reacting cyanobenzamide with a metal salt at high temperature, and the method of reacting dilithium phthalocyanine with a metal salt. Also as an organic solvent.

α-chloronaphthalene, β-chloronaphthalene, α-methylnaphthalene, methoxynaphthalene, diphenylethane, ethylene glycol, dialkyl ether, quinoline, sulfolane, dichlorobenzene.

Reaction-inert, high-boiling solvents such as dichlorotoluene are preferred. That is, in the above organic solvent, 150 to 300°C
It can be synthesized by heating and stirring in the temperature range of . Also, instead of phthalodinitrile, indoline compounds such as diiminoisoindoline, or 1-amino-3
- Indolenine compounds such as iminoisoindolenine can also be used.

The phthalocyanine used in the present invention is described in "Phthalocyanine Compound J" by Moser and Thomas.
nd Thomas″Phtha 1ocyanin
Compounds obtained by known methods such as "e Compounds") and the appropriate methods described above are treated with acids, alkalis,
Acetone, methyl ethyl ketone, tetrahydrofuran,
Pyridine, quinoline, sulfolane, α-chloronaphthalene, toluene, dioxane.

Xylene, chloroform, carbon tetrachloride, dichloromethane, dichloroethane, trichloropropane, N.

N-dimethylacetamide, N-methylpyrrolidone,
Obtained by purification with N,N''-dimethylformamide, etc. Purification methods include washing method and recrystallization method.

Examples include extraction methods such as Soxhlet, and thermal suspension methods.

It is also possible to purify by sublimation. Purification methods are not limited to these, and unreacted substances can be purified.

Any action that removes reaction by-products and impurities may be used.

Metal phthalocyanine compound produced by the above method,
Mainly dilithium phthalocyanine (LizPc),
Alkali metal phthalocyanines such as disodium phthalocyanine (NazPc) and dipotassium phthalocyanine (K□Pc) are demetallized by an acid pasting method to obtain a metal-free phthalocyanine compound.

The acid pasting method is a conventionally known pigmentation method using a strong acid such as sulfuric acid. crude pigment (crud)
The acid pasting method is a process in which E. pigment) is dissolved in a relatively large amount of concentrated sulfuric acid or the like.

The metal-free phthalocyanine compound demetallized by the acid pasting method has an α-type crystal form. α-type metal-free phthalocyanine compounds generally do not have sufficient electrophotographic properties such as photoconductivity and cannot be used as charge-generating materials. Therefore, by milling this α metal-free phthalocyanine compound and applying mechanical shearing force or strain force, it is possible to cause crystal transition to the metal-free phthalocyanine compound of the present invention and use it as a charge generating material for electrophotographic photoreceptors. made possible.

The equipment used for milling is Nigoo.

These include, but are not limited to, Banbury mixers, attritors, edge runner mills, roll mills, ball mills, sand mills, 5PEX mills, homomixers, dispersers, agitators, show crushers, stamp mills, cutter mills, micronizers, etc. .

Dispersion media that may be used include, but are not necessarily required to include, for example, glass beads, steel beads, zirconia beads, alumina balls, zirconia balls, steel balls, and flint stones.

Further, if necessary, it is also possible to use a grinding aid such as common salt or sulfur sulfate. For particle preparation, a dry method that applies strain force or shear force to the sample most efficiently, or a wet method that allows easy adjustment of particles uniformity is selected. The wet method uses a liquid solvent during milling. For example, alcohol-based solvents such as glycerin, ethylene glycol, diethylene glycol, polyethylene glycol, carpitol-based solvents,
Cellosolve solvent.

One or more types are selected from ketone solvents, ester ketone solvents, and the like.

The temperature during milling is 30-220℃, preferably 60-220℃
130°C is desirable.

The charge generation layer using the metal-free phthalocyanine compound obtained by the present invention is a uniform layer with high light absorption efficiency,
Between particles in the charge generation layer, between the charge generation layer and the charge transfer layer,
There are few voids between the charge generation layer and the undercoat layer or the conductive substrate, which provides characteristics as an electrophotographic photoreceptor such as potential stability and prevention of increase in bright area potential during repeated use, and reduced zero image defects. , stiffness resistance, etc.

An electrophotographic photoreceptor that satisfies many requirements can be obtained.

An n-type photoreceptor is fabricated by laminating an undercoat layer, a charge generation layer, and a charge transfer layer in this order on a conductive substrate. In addition, the p-type photomaterial is obtained by laminating a charge transfer layer and a charge generation layer in this order on an undercoat layer, or by dispersing and coating a charge generation agent and a charge transfer agent together with an appropriate resin on the undercoat layer. There is something created. If necessary, an overcoat layer may be provided on both photoreceptors for surface protection and prevention of toner filming.

Further, the undercoat layer can be removed if unnecessary.

The metal-free phthalocyanine compound of the present invention can be suitably used for all of the above-mentioned various photoreceptors. Also.

The charge generation layer can be obtained by dispersing and coating a metal-free phthalocyanine compound and a resin in a suitable solvent, but if necessary, it can also be used by dispersing and coating only a solvent without the resin.

The material obtained by the present invention can be deposited with extremely high efficiency (vapor deposition) because it is processed down to the minute primary particles and impurities existing between the particles are removed.

It is also effective as a material for vapor deposition.

For coating the photoreceptor, use a spin coater, applicator, spray coater, bar coater, titf4 coater,
This is done using a doctor blade, roller coater, curtain coater, or bead coater.

Drying is performed at 40 to 200° C. for 10 minutes to 6 hours under stationary or blowing air conditions. The film thickness after drying is 0. It is coated to a thickness of 5 microns from Ol, preferably 0.1 to 1 micron.

The binder that can be used when forming the charge generation layer by coating can be selected from a wide variety of insulating resins.

It can also be selected from organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinylanthracene and polyvinylpyrene. Preferably polyvinyl butyral,
Polyarylate (condensation polymer of bisphenol A and phthalic acid, etc.), polycarbonate, polyester, phenoxy resin, polyvinyl acetate, acrylic resin, polyacrylamide resin, polyamide resin, polyvinylpyridine, cellulose resin, urethane resin, epoxy resin, silicone Insulating resins such as resin, polystyrene, polyketone resin, polyvinyl chloride, vinyl chloride copolymer, polyvinyl acecool, polyvinyl formal, polyacrylonitrile, phenol resin, melamine resin, casein, polyvinyl alcohol, polyvinylpyrrolidone, etc. Can be done. The resin contained in the charge generation layer is 100% by weight.
Below, preferably 40 times % or less is suitable. Further, these resins may be used alone or in combination of two or more. The solvent for dissolving these resins varies depending on the type of resin, and it is preferable to select a solvent that does not affect the charge generation layer or undercoat layer described later during coating.Specifically, solvents such as benzene, xylene, ligroin, and monochloride are selected. Aromatic hydrocarbons such as benzene and dichlorobenzene, ketones such as acetone, methyl ethyl ketone, and cyclohexanone.

Alcohols such as methanol, ethanol, isopropanol, esters such as ethyl acetate, methyl cellosolve, carbon tetrachloride, chloroform, dichloromethane,
Aliphatic halogenated hydrocarbons such as dichloroethane and trichloroethylene, tetrahydrofuran, dioxane,
Ethers such as ethylene glycol monomethyl ether, amides such as N,N-dimethylformamide, N,N-dimethylacetamide, and sulfoxides such as dimethyl sulfoxide are used. The charge generation layer can also be formed by vapor deposition, and 10-'= l O
The film is deposited under a vacuum of about -bTorr, and the film thickness is from 0.01 to 5 microns, preferably from 0.05 to 0.5 microns.

The charge transfer layer is formed by dissolving and dispersing a charge transfer agent alone or in a binder resin. Charge transfer substances include electron transfer substances and hole transfer substances.

Any charge transfer agent may be used, but materials such as oxazole compounds, oxadiazole compounds, hydrazone compounds, pyrazoline compounds, stilbene compounds, triphenylamine compounds, and butadiene compounds are suitable.

The binder resin, solvent and coating method are selected from those described for the charge generating layer. The film thickness after drying is preferably 15 to 20 microns.

In addition to these layers, an undercoat layer can be provided on the conductive substrate for the purpose of preventing deterioration of chargeability, improving adhesion, and the like. As an undercoat layer, nylon 6, nylon 66, nylon 11. Polyamides such as nylon 61O2 copolymerized nylon and alkoxymethylated nylon, casein, polyvinyl alcohol, nitrocellulose, and ethylene-acrylic acid copolymer.

Gelatin, polyurethane, polyvinyl butyral and metal oxides such as aluminum oxide are used. Also, metal oxides such as zinc oxide and titanium oxide.

The resin can also be prepared by incorporating conductive and dielectric particles such as silicon nitride, silicon carbide, and carbon Bragg.

Hereinafter, one embodiment of the present invention will be specifically described.

In the examples, part means 1 part by weight.

Examples 1 to 3 3 parts of the metal compounds shown in Table 1 and 14.5 parts of aminoiminoisoindolenine were mixed in 50 parts of trichlorobenzene at 20%
After heating for 2 hours at 0°C and 9 reactions, the solvent was removed by steam distillation, and the metal phthalocyanine was purified by using a 2% aqueous hydrochloric acid solution, followed by a 2% aqueous sodium hydroxide solution, thoroughly washed with water, and dried. Obtained.

The metal phthalocyanine thus obtained has a β-type crystal form.

Table 1 The transition from β type to α type is produced by the following operation.

One part of β-type metal phthalocyanine is dissolved little by little in IO part of 98% sulfuric acid at below 10°C, and the mixture is stirred for about 2 hours while maintaining the temperature below 5°C. Subsequently, the sulfuric acid solution was poured into 200 parts of ice water.

Filter the precipitated crystals. The crystals are washed with distilled water until no acid remains and are dried to obtain 0.95 parts of α-type metal-free phthalocyanine.

The α-type metal-free phthalocyanine obtained by the above method has a Bragg angle (2θ±0.2°) of 6.7°, 7.2°,
13.5°, 14.8°, 15.3°, 16.2°, 2
It has clear X-ray diffraction peaks at 4, 1°, 24.8°, 26.6° and 27.3° (Cu
Kα radiation). The X-ray diffraction pattern of the α-type metal-free phthalocyanine of Example 1 is shown in FIG.

Next, 100 parts of this α-type metal-free phthalocyanine.

200 parts of common salt and 80 parts of polyethylene glycol were placed in a Nigu and milled at 60 to 130°C for 8 hours. After taking it out, it was purified with a 2% sulfuric acid solution.

A novel metal-free phthalocyanine compound of the present invention was obtained by filtration, washing with water, and drying.

The metal-free phthalocyanine compound obtained by the above method has a Bragg angle (2θ±0.2°) of 6.7'.

7.3°, 13.5°, 14.9°,
15.9°, 16.7'.

It had clear X-ray diffraction peaks at 24.7° and 26.1".
A line diffraction diagram is shown in FIG. For Bragg angles below 200, most have peaks at the same position as the α type, but
It is presumed that the peaks of 200 or more differ greatly and are reflected in a structure with excellent photoconductivity.

Next, a method for manufacturing an electrophotographic photoreceptor will be described.

Copolymerized nylon (Amiran CM-8000 manufactured by Toshi) 10
was mixed with 190 parts of ethanol in a ball mill for 3 hours, and the dissolved coating liquid was applied with a wire bar onto a sheet of polyethylene terephthalate (PET) film with aluminum vapor-deposited, and then dried at 100°C for 1 hour. A sheet having a subbing layer with a thickness of 0.5 microns was obtained.

Two parts of the metal-free phthalocyanine obtained in this example was dissolved in THF.
97 parts and 1 part of polyvinyl butyral resin (B
H-3) was dispersed in a ball mill for 6 hours together with the dissolved resin liquid.

After applying this dispersion onto the undercoat layer and drying it.

Form a charge generation layer of 0.2 microns 3. Next, use 1-phenyl-1,2,3,4-tetrahydroquinoline-6-carpoxyaldehyde 1',1'-diphenyl as a charge transfer agent. A solution prepared by dissolving 10 parts of polycarbonate resin (Kijin Kasei Panrye L-1300) in 100 parts by weight of methylene chloride was applied onto the charge generation layer and dried to form a charge transfer layer of 15 microns. We obtained the body and measured its properties.

Electrophotographic properties were measured by the following method.

Static mode 2. Corona charging is -5° 2KV with 1 surface potential (■0) and 51ux white light or lμ
The amount of charge is 1/2 when irradiated with 800 parts m of light adjusted to W.
The white light half-exposure sensitivity (El/2
) was investigated.

Table 2 Comparative Examples 1 to 3 Electrophotographic photoreceptors were prepared in the same manner as in Examples 1 to 3, except that the α-type metal-free phthalocyanine prepared in Examples 1 to 3 was used as a charge generating agent, respectively.

Its properties were measured. The results are shown in Table 3.

Table 3 From the above results, the metal-free phthalocyanine of the present invention.

Alpha-type metal-free phthalocyanine, which is the starting material for milling, has excellent photoconductivity and chargeability.

The charging property was −120 (V) or less, and the sensitivity was also significantly inferior. Therefore, the metal-free phthalocyanine of the present invention is 78
It can be effectively used as a charge-generating material for a photoreceptor for a semiconductor laser having an oscillation wavelength of 0na+.

[Brief explanation of the drawing]

Figures 1 and 2 show the α-type metal-free phthalocyanine prepared in Example 1 and the new metal-free phthalocyanine, respectively.
Line diffraction diagram.

Claims (1)

[Claims] 1. Bragg angle (2θ±0.2°) of 6.7°; 7.
3°, 13.5°, 14.9°, 15.9°, 16.7
A metal-free phthalocyanine compound with an X-ray diffraction diagram showing distinct X-ray diffraction peaks at positions 24.7°, 24.7° and 26.1°. 2. A metal-free phthalocyanine compound prepared by removing metal from a metal phthalocyanine compound by an acid pasting method is heated at 30 to 220°C, preferably 60 to
2. The method for producing a metal-free phthalocyanine compound according to claim 1, wherein the crystal conversion is carried out by milling at 130° C. with mechanical strain. 3. In an electrophotographic photoreceptor using a charge generating agent and a charge transfer agent on a conductive support, the charge generating agent is
An electrophotographic photoreceptor comprising the metal-free phthalocyanine compound according to claim 1.