JPH02178358A - Novel phthalocyanine compound and sensitive material for electrophotography using the compound - Google Patents

Abstract

NEW MATERIAL:The compound of formula I [M is V, Ti, Mo, Si, Ge or Sm; A and B are atoms selected from O, S, Se and Te which may be bonded with H; either A or B may be bonded to M through a double bond; R1-R4 are H, halogen, On, nitro, cyano, amino, carbonyl, alkoxy, (substituted) alkyl, allyl or aryl: a, b, c and d are 0-6]. EXAMPLE:Thiotitanium phthalocyanine. USE:A sensitive material for electrophotography. PREPARATION:The objective compound can be produced by stirring a phthalocyanine precursor such as phthalodinitrile of formula II and a metal chloride of formula MX4 (X is halogen) under heating in an inert solvent having high boiling point in nitrogen atmosphere to synthesize a dihalogeno-metal phthalocyanine of formula MCl2Pc (Pc is phthalocyanine), adding a reactive sulfur compound, selenium compound or tellurium compound to the synthesized phthalocyanine compound and stirring the mixture under heating.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a phthalocyanine compound, and further relates to a highly sensitive electrophotographic photoreceptor.

(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 to the short wavelength region are unsuitable for use in semiconductor lasers;
It has become necessary to research materials that have tube sensitivity at wavelengths of 780 nm and above. Recently, we have been using organic materials, especially phthalocyanine, which is expected to have sensitivity in the long wavelength region.

Research into multilayer organic photoreceptors in which these materials are laminated is being actively conducted. For example, as a divalent phthalocyanine, ε
Type 1 metal-free phthalocyanine (ε-CuPc), X-type metal-free phthalocyanine (X-H2Pc), and τ-type metal-free phthalocyanine (τ-t (2Pc)) are sensitive in the long wavelength region.Trivalent and tetravalent metal phthalocyanines Examples include chloroaluminum phthalocyanine (AfPcC6) and chloroaluminum phthalocyanine chloride (CnA7!).
PcCj, oxotitanium phthalocyanine (TiO
Pc) or chloroindium phthalocyanine N n
A method of laminating P c Cl and then contacting it with the vapor of a soluble solvent to achieve long wavelength and high sensitivity (Japanese Patent Application Laid-Open No. 57-39
No. 484, JP-A No. 59-166959), a method in which phthalocyanine containing TiSn and Pb as Group Ⅰ metals is subjected to long wavelength treatment using various substituents, derivatives, or shifting agents such as crown ethers ( Special request 1977
No. 9-36254 and Japanese Patent Application No. 59-204045), sensitivity is obtained in three long wavelength regions.

For example, oxotitanium phthalocyanine or indium chlorophthalocyanine is vapor-deposited on a substrate as described in JP-A-59-166959.

Next, in an electrophotographic photoreceptor provided with a charge generation layer formed by contacting with the vapor of a soluble solvent, the deposited layer crystallizes, resulting in nonuniform film thickness, resulting in deterioration of electrophotographic characteristics and image defects. cause. Also, JP-A-59-495
A charge generation layer was prepared using oxotitanium phthalocyanine described in Publication No. 44.

An electrophotographic photoreceptor in which a charge transfer layer mainly composed of polyester made from 2,6-simethoxy9,10-dihydroxyanthracene as a raw material is provided thereon has a high residual potential.
There are many restrictions on how to use it.

Conventionally known phthalocyanine compounds are often in the form of solidly agglomerated lumpy particles, and many impurities are contained between the agglomerated particles. Furthermore, because crystals inevitably grow during crystallization, and because pigment particles have large diameters, charge generation layers deposited and dispersed using these pigments lack uniformity and dispersion stability. As a result, it was difficult to obtain a homogeneous charge generation layer, and it was not possible to obtain a beautiful image or a stable photoreceptor.

In these cases, the light absorption efficiency is insufficient, resulting in a decrease in the carrier generation efficiency of the charge generation layer 1 A decrease in the injection efficiency of carriers into the charge transfer layer, and a decrease in deterioration resistance and stiffness resistance during repeated use over a long period of time 9 Image It had the drawback of not fully satisfying electrophotographic photoreceptors, such as stability.

(Problems to be Solved by the Invention) The object of the present invention is to provide a novel phthalocyanine compound,
Furthermore, by using the compound in the photosensitive layer, an electrophotographic photoreceptor having excellent exposure sensitivity characteristics (1) spectral sensitivity, as well as deterioration resistance, printing durability, and image stability during repeated use over a long period of time (JtJ) can be obtained. It's about getting.

[Structure of the invention]

(Means and effects for solving the problems) The present invention has the following features:
A compound represented by the following general formula [I] (wherein 1M is V,
Metal atoms selected from Ti, Mo, St, Ge, and Src; A and B may be the same or different; O, S, and Se may be bonded to H;

Represents an atom selected from Te, and only one of A and B may form a double bond with the metal atom M. R+, RzRs
=Ra is a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group,
A cyano group, an amino group, a carbonyl group, an alkoxy group, and an alkyl group that may have a substituent.

Represents an allyl group, an aryl group, a, b, c, d are O-6
represents an integer. ) Furthermore, it is an electrophotographic photoreceptor having a photosensitive layer on a conductive support, in which the photosensitive layer contains the compound of the above-mentioned removal allowance [I].

In addition, 5 the phthalocyanine compound of the present invention has the above-mentioned
Any X-ray diffraction pattern may be shown as long as it has the molecular structure of I).

The method for producing the phthalocyanine compound of the present invention is shown below.

Generally, phthalocyanine is produced by 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 fucuric acid anhydride with urea and a metal chloride, or by heating in the presence of an organic solvent. There are 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.

The phthalocyanine compound of the present invention may be synthesized by any method, but preferably, a phthalocyanine precursor selected from phthalodinitrile, diiminoisoindoline, and aminoiminoisoindolenine and a metal chloride are synthesized in an inert manner. Addition in a high boiling point solvent under nitrogen atmosphere 2! ′! By stirring, dihalogenometal phthalocyanine is synthesized, and a more reactive sulfur compound.

It is prepared by adding a compound selected from selenium compounds and tellurium compounds and then heating and stirring. A scheme for synthesis from phthalodinitrile is shown below.

(Here, 1M is V, Ti, Mo, Si, Ge, 3n metal atom, L is S, Se, 'l'e, X is halogen atom,
e is an integer of 1 or 2, and Pc represents a phthalocyanine molecule. ) The organic solvents used in the present invention include α-lihylonaphthalene, β-chloronaphthalene, α-methylnaphthalene,
Methoxynaphthalene, diphenylethane.

Ethylene glycol, dialkyl ether, quinoline,
Reactive, high-boiling solvents such as sulfolane and dichlorobenzene are desirable.

In addition, reactive sulfur, selenium, and tellurium compounds that substitute for halogen atoms in dihalogenometal phthalocyanine include hydrogen sulfide, tetraphosphorus heptasulfide, tetraphosphorus decasulfide, dithiophosphetane, 2,4-bis-(4methoxy phenyl)
-1,3-dithia-2,4-diphosphethane-2,4-
Disulfides include, but are not limited to, selenium pentasulfide, selenium disulfide, selenophenol, selenopurine, selenourea, tellurium, tellurium dioxide, tellurium chloride, and the like. The phthalocyanine compounds synthesized according to the present invention include acids, alkalis, acetone, methyl ethyl ketone, tetrahydrofuran, pyridine, quinoline, sulfolane, α-chloronaphthalene, toluene, dioxane, xylene 3 chloroporum, carbon tetrachloride 1 dichloromethane, dichloroethane, trichloropropane, N, N'-
Dimethylacetamide, N-methylpyrrolidone, N,N
' - Purify with dimethylformamide or the like. Purification methods include one or more solvent washing methods, recrystallization methods, extraction methods such as Soxhlet, and thermal suspension methods.

The phthalocyanine compound obtained by the above method can be further purified by sublimation to produce the desired phthalocyanine compound.

Sublimation purification is a purification method suitable for purifying molecular compound crystals such as phthalocyanine. The sublimation purification method will be briefly explained.

The substance to be purified is placed in a part of the glass-sealed tube, and the pressure is reduced using a vacuum pump. The glass sealed tube containing the substance to be purified is placed in a heating filter and heated. Impurities and decomposed products adhere to different locations from purified products, so they can be easily separated.

The optimum temperature for hot filtration varies depending on the substance to be purified, but in the case of the phthalocyanine compound of the present invention, a temperature of 200°C or higher is desirable.

Further, it is desirable that the pressure inside the sealed tube be reduced to 10-' Torr or less. The phthalocyanine compound obtained by the powder method can also be used after being made fine by a mechanical grinding method. If necessary, it is also possible to use a grinding aid such as common salt, sulfur salt, glass peas, or flint stone during grinding.

Equipment used during grinding includes a kneader, Banbury mixer, attritor, mill, Giranna Mill 1 roll mill, ball mill, sand mill, 5PEX mill, homo mixer, disperser, Ajita Jaw Crano Shear, stamp mill, cutter mill, Examples include micronizers, but are not limited to these.

The charge generation layer using the phthalocyanine compound obtained according to 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 gaps between the charge generation layer and the undercoat layer or conductive substrate, resulting in stable potential during repeated use.

Characteristics as an electrophotographic photoreceptor such as prevention of increase in bright area potential,
It is possible to obtain an electrophotographic photoreceptor that satisfies many requirements such as reduction in image defects and rigidity resistance.

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. P-type photoreceptors are made 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 a suitable resin on the undercoat layer. There are things that have been done. If necessary, an overcoat layer may be provided on both photoreceptors for surface protection and prevention of toner filming.

The phthalocyanine compound of the present invention can be suitably used for all of the above-mentioned various photoreceptors. Further, the charge generation layer can be obtained by dispersing and coating a phthalocyanine compound and a resin in an appropriate solvent, but if necessary, it can also be used by dispersing the phthalocyanine compound and the resin without the resin.

It is also known that a charge generation layer can be obtained by vapor deposition.
The material obtained by the present invention has been processed down to the minute primary particles.5 Furthermore, the crystals are extremely well-organized using an appropriate solvent, so impurities existing between particles can be removed, making it possible to deposit the material very efficiently. It is also effective as a material for vapor deposition.

Coating of the photoreceptor is carried out using a spin coater, Ab IJ catasbrake coater, bar coater, immersion 1 coke doctor blade, roller coater, curtain coater, bead coater device, and vapor deposition device, and drying is not necessary. If available, heat dry at 40 to 200℃ for 10 minutes to 6
Carry out under stationary or ventilated conditions for a range of hours. After drying, the film is coated to a thickness of 0.01 to 5 microns, preferably 0.05 to 1 micron.

The binder that can be used when forming the charge generation layer by coating can be selected from a wide range of insulating resins.
It can be selected from organic photoconductive polymers such as 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 resin, polystyrene, polyketone resin, polyvinyl chloride, vinyl chloride acid copolymer, polyvinyl acetal, polyacrylonitrile, phenolic resin, melamine resin, casein, Examples include insulating resins such as polyvinyl alcohol and polyvinylpyrrolidone. 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 transfer layer and undercoat layer described later during coating. M Physically, he's weird. xylene, ligroin.

Aromatic hydrocarbons such as monochlorobenzene and dichlorobenzene, ketones such as acetone, methyl ethyl ketone and cyclohexanone, alcohols such as methanol, ethanol and isopropanol, esters such as ethyl acetate and methyl cellosolve, carbon tetrachloride, chloroform, Aliphatic halogenated hydrocarbons such as dichloromethane, dichloroethane, trichloroethylene, ethers such as tetrahydrofuran and dioxane ethylene glycol monomethyl ether, amides such as N,N-dimethylformamide, N,N dimethylacetamide,
and sulfoxides such as dimethyl sulfoxide.

The charge transfer layer is formed by a charge transfer agent alone or by dissolving and dispersing the charge transfer agent in a binder resin. The charge transfer agents used in the present photoreceptor can be used alone or in combination of two or more. What resin is used for the charge transfer layer?

Silicone resin, ketone resin, polymethyl methacrylate, polyvinyl chloride, acrylic resin, polyarylate, polyester 9 polycarbonate, polystyrene, acrylonitrile-styrene copolymer, acrylonitrile-
Butadiene copolymer, polyvinyl butyral, polyvinyl formal, polysulfone, polyacrylamide,
Insulating resins such as polyamide and chlorinated rubber, poly-N-
Vinyl carbazole.

Polyvinylanthracene, polyvinylpyrene, polysilane, etc. are used.

The coating method is performed using a spin coater, applicator spray coater, bar coater, dip coater doctor blade, roller coater, curtain coater, or bead coater, and the film thickness after drying is 5 to 50 microns, preferably 10 to 20 microns. It is best to use a coating that looks like this.

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. Nylon 610. Polyamides such as copolymerized nylon and alkoxymethylated nylon, casein, polyvinyl alcohol, nitrocellulose, ethylene-acrylic acid copolymers, gelatin, polyurethane, polyvinyl butyral, and metal oxides such as aluminum oxide are used.

Further, it is also possible to adjust the resin by incorporating metal oxides such as zinc oxide and titanium oxide, and R-electric and dielectric particles such as silicon nitride, silicon carbide and carbon Bragg into the resin.

The material of the present invention has an absorption peak at a wavelength of 760 nm or more, and is suitable not only for use as an electrophotographic photoreceptor in copying machines and printers, but also as an absorption material for solar cells, photoelectric conversion elements, and optical disks.

(Example) Two embodiments of the present invention will be specifically described below.

In the examples, part means 1 part by weight.

Example 1 20.4 parts of phthalodinitrile and 7.6 parts of titanium tetrachloride were subjected to a heating reaction in 200 parts of quinoline at 220°C for 4 hours under a nitrogen atmosphere. Thereafter, hydrogen sulfide gas was injected instead of nitrogen gas, and the heating reaction was continued at 220'C for 10 hours. After the reaction is complete, remove the solvent by steam distillation.

Purified in the order of acetone and methanol, dried to 19°4
Part of a phthalocyanine compound was obtained. Mass spectrometry result M/
Z=592, and furthermore, from the results of elemental analysis, the compound obtained in this example was thiotitanium phthalocyanine (
TiSPc).

FIG. 1 shows the IR absorption spectrum (solid line) of thiotitanium phthalocyanine synthesized in Example 1.

The IR absorption spectrum of oxotitanium phthalocyanine is shown by a broken line. In the compound of Example 1, absorption at 972c+n-', which is characteristic of oxotitanium phthalocyanine, is not observed.

Example 2 20.2 parts of phthalodinitrile, 9.7 parts of vanadium trichloride
A phthalocyanine compound was prepared in the same manner as in Example 1 except that 18.3 parts of the phthalocyanine compound was obtained. As a result of mass spectrometry single element analysis, thiovanadium phthalocyanine (VSP
C).

Example 3 A phthalocyanine compound was prepared in the same manner as in Example 1 except that 20 parts of phthalodinitrile and 13.1 parts of molybdenum hexachloride were used to obtain 17.8 parts. As a result of mass spectrometry five-element analysis, thiogermanium phthalocyanine (MoS
Pc).

Example 4 A phthalocyanine compound was prepared in the same manner as in Example 1 except that 20 parts of phthalodinitrile and 10.1 parts of tin tetrachloride were used to obtain 18.3 parts. Mass spectrometry.

As a result of elemental analysis, thiostin phthalocyanine (S n 5
Pc).

Example 5 20 parts of aminoiminoisoindolenine, 7 parts of silicon tetrachloride
．． A phthalocyanine compound was prepared in the same manner as in Example 1 except that 0 part was used, and 20.1 parts were obtained.

As a result of mass spectrometry two-element analysis, it was found to be thiosilicon phthalocyanine (SiSPc).

Example 6 A phthalocyanine compound was prepared in the same manner as in Example 1 except that 19.8 parts of aminoiminoisoindolenine and 9.6 parts of germanium tetrachloride were used to obtain 17.3 parts. As a result of single element mass spectrometry analysis, it was found to be thiogermanium phthalocyanine (GeSPc).

Examples 7 to 24 Phthalocyanine compounds were produced in the same manner as Examples 1 to 6, except that the metal source and raw materials were changed and the metal coordination atoms and substituents of the phthalocyanine compounds were changed. The prepared compounds are shown in Table 1. The structures of the compounds shown in Table 1 were confirmed by mass spectrometry single element analysis and NMR analysis.

Next, a method for producing an electrophotographic photoreceptor using this phthalocyanine compound as a charge generating agent 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 to form a film with a thickness of 0. 5
A sheet with a micron subbing layer was obtained.

After thoroughly grinding 2 parts of the phthalocyanine obtained in this example with a sand mill, 1 part of vinyl chloride-vinyl acetate copolymer resin was added to 97 parts of THF.
(Union Carbide Co., Ltd. VMC) I) was dispersed in a ball mill for 6 hours together with the dissolved resin liquid.

After coating this dispersion on the undercoat layer and drying it,
A micron charge generation layer was formed.

Next, as a charge transfer agent, -1 part of the compound of Torido [11],
Polycarbonate resin (Kijin Kasei (Semi-turbid Panlight L)
-1250) was mixed and dissolved in 8 parts of methylene chloride.

This liquid was applied onto the charge generation layer and dried to form a charge transfer layer of 15 microns, and the electrophotographic properties were measured.

No. table The electrophotographic properties of the photoreceptor were measured by the following method.

Static mode 2. Corona charge is 1 at -5.2KV
Irradiate the surface type with 5 Lux of white light to increase the charge amount to 1.
White light half-reduced exposure sensitivity (El
/2) was investigated. Also, the evaluation of repeatability is -5,2
KV, charged at a corona linear velocity of 120 mm/sec,
The sample was left in a dark place for 2 seconds and then exposed to light at 5 Lux for 3 seconds, and the changes in surface pattern position and sensitivity were measured repeatedly.

The results of electrophotographic properties are shown in Table 2.

Based on the above results, the photoreceptors of Examples 1 to 24 are as follows.

It had a sufficient surface potential, and both sensitivity and residual potential were good. The compounds of the present invention had good properties regardless of the central metal or substituents.

Comparative example 1 Except for using ε-type copper phthalocyanine as the charge generating agent.

A photoreceptor was produced in the same manner as in Example 1, and its electrophotographic properties were measured. The results are shown in Table 3.

4゜[Effects of the Invention] According to the present invention, a novel phthalocyanine compound was obtained. Furthermore, by using the compound in the photosensitive layer, an electrophotographic photoreceptor having excellent sensitivity, chargeability, and image stability was obtained.

[Brief explanation of the drawing]

FIG. 1 shows the IR absorption spectrum (solid line) of thiotitanium phthalocyanine synthesized in Example 1. The IR absorption spectrum of oxotitanium phthalocyanine is shown by a broken line.

Claims (1)

[Claims] 1. A compound represented by the following general formula [I]. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [I] (In the formula, M is a metal atom selected from V, Ti, Mo, Si, Ge, Sn, A and B may be the same or different, and bond with H. Represents an atom selected from O, S, Se, and Te that may be
May be double bonded with. R_1, R_2, R_3, R_
4 represents a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a cyano group, an amino group, a carbonyl group, an alkoxy group, and an alkyl group, an allyl group, an aryl group that may have a substituent, and a, b, c, d represents an integer from 0 to 6. 2. An electrophotographic photoreceptor having a photosensitive layer on a conductive support, which contains the compound according to claim 1 in the photosensitive layer.