JPH01217362A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To enhance exposure sensitivity characteristics and wavelength characteristics, further deterioration resistance characteristics at the time of repeated uses for a long time, printing resistance, and image stability by using a vanadium phthalocyanine compound as an electric charge generating material. CONSTITUTION:The electrophotographic sensitive body is provided on a conductive substrate with a photosensitive layer containing as a charge transfer material and the charge generating material represented by formula I in which R1 is halogen, oxygen, hydroxy, nitro, or alkoxy; each of R2-R5 is H, halogen, alkyl, alkoxy, allyl, or aryl; (j) is 1 or 2; each of (k), (l), (m), and (n) is an integer of 0-4, thus permitting the obtained photosensitive body to have superior exposure sensitivity characteristics, wavelength characteristics, deterioration resistance characteristics at the time of repeated uses for a long period, printing resistance, and image stability.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to an electrophotographic photoreceptor using a phthalocyanine containing vanadium as a central metal, and more specifically, it relates to an electrophotographic photoreceptor that has excellent exposure sensitivity. The present invention relates to an electrophotographic photoreceptor having specific characteristics and wavelength characteristics.

(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 780 nm and above. Recently, research has been actively conducted on multilayer organic photoreceptors that use organic materials, especially phthalocyanin, which is expected to have sensitivity in the long wavelength region. For example, as a divalent metal 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. As trivalent and tetravalent metal phthalocyanine, chloroaluminum phthalocyanine (A#PcCjl
, chloroaluminum phthalocyanine chloride (Cj
iAj! PcC1), or titanyl phthalocyanine (
TiOPc), chloroindium phthalocyanine (In
A method of vapor depositing PcC1) and then contacting it with the vapor of a soluble solvent to achieve long wavelengths and high sensitivity (Japanese Patent Application Laid-open No. 5'1-394
No. 84, JP-A No. 59-166959), phthalocyanine containing Ti, Sn and Pb as Group Ⅰ metals can be converted to a longer wavelength by using various substituents, derivatives or crown ethers, etc. -3 = other agents. Processing method (Patent application 1986-36)
No. 254, special request from 1977! ]-'204045), sensitivity is obtained in the long wavelength region.

The use of vanadyl phthalocyanine (VOPC) as a charge generating agent for electrophotographic photoreceptors is disclosed in Japanese Patent Application Laid-Open No. 54-149.
No. 634, JP-A No. 57-1' 46255.

JP-A-57-147641, JP-A-57-14874
No. 7, JP-A No. 57-148748, etc., but the charge generating agent is limited to compounds having the chemical structural formula of VOPc. In addition, charge transfer agents are benzidine derivatives,
Oxadiazole derivatives, triphenylmethane derivatives,
Hydrazone derivatives and 2゜4.7-)dinitro-9-
The combination is limited to fluorenone (TNF'). However, the photoreceptors obtained by these methods have the disadvantage of not only low sensitivity but also high dark decay, which is an important and necessary electrophotographic property. Furthermore, benzidine derivatives,
Oxadiazole derivatives, triphenylmethane derivatives, and hydrazone derivatives are unstable to ultraviolet light, so they cannot be considered practical photoreceptors, and 'TNF cannot be used in practice due to its toxicity. . As described above, it has not been possible to obtain a practical photoreceptor using the combination of V'OPc and the charge transfer agent that has been used so far.

LEDs have also been put into practical use as digital light sources for printers. Although LEDs in the i-light range are also used, those that are generally put into practical use have an oscillation wavelength of 650 nm 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:
An electrophotographic photoreceptor comprising a charge generating agent and a charge transfer agent on a conductive support.

The present invention relates to an electrophotographic photoreceptor in which the charge generating agent is a vanadium phthalocyanine compound represented by -Noshiro CI).

(In the formula 5, R1 is a halogen atom, an oxygen atom, or a hydroxyl group.

R2-R6 represent a hydrogen atom, a halogen atom, an alkyl group, a 2-alkoxy group, an allyl group, an aryl group, an aryloxy group, a 4-nido group, a cyano group, a hydroxyl group, and a benzyloxy group. , has a substituent such as an amino group, but R2-R5 are not all hydrogen atoms.

j is an integer of 1 or 2; m and n are 0
Represents the number ~4. Furthermore, the above object has been achieved by an electrophotographic photoreceptor characterized in that the charge generation agent is the vanadium phthalocyanine compound and the charge transfer agent is a compound represented by the general formula Cl0).

(In the formula, R61R? is a hydrogen atom, an alkyl group, an alkoxy group, or an aryl group, R111R9+ R
1° represents a hydrogen atom or a -NR6(R?) group, and n is O or 1. ) The vanadium phthalocyanine compound of the present invention is a compound having a substituent on the central vanadium metal and/or the outer benzene ring, and the substituent may be any type as long as it is of the type of general formula (T), .

It may be a mixture of two or more types. Also, - Noshiro (1)
If it is a vanadium phthalocyanine compound.

It may have any crystal type and X-ray diffraction pattern. A method for producing the vanadium phthalocyanine compound of the present invention will be described.

Phthalocyanine can be produced using the phthalodinitrile method, in which phthalodinitrile and a metal compound are heated and melted or heated in the presence of an organic solvent, the Weiler method, in which phthalic anhydride is heated and melted with urea and a metal chloride, or heated in the presence of an organic solvent, and the cyanomethod. Methods include, but are not limited to, a method in which henzamide and a metal salt are reacted at a high temperature, and a method in which dilithium fucrocyanine and a metal salt are reacted. Examples of organic solvents include reaction-inactive high-boiling point solvents such as α-chloronaphthalene, β-chloronaphthalene, α-methylnaphthalene, methoxynaphthalene, diphenylethane, ethylene glycol, dialkyl ether, quinoline, sulfolane, and dichlorobenzene. desirable.

Also, by a method in which substituents are added to phthalocyanine raw materials such as phthalodinitrile, intrene compounds, indolenine compounds, phthalic anhydride, and cyanobenzamide, and then condensed with metal compounds.

Metal phthalocyanines having substituents can be synthesized. By the above method, the obtained compound is acidified.

=9- Alkali, acetone, methyl ethyl ketone, tetrahydrofuran, pyridine, quinoline, sulfolane.

α-chloronaphthalene, toluene, dioxane, xylene 5-chloroform, carbon tetrachloride, dichloromethane, dichloroethane, trichloropropane, N.

N''-dimethylacetamide, N~methylpyrrolidone,
Obtained by purification with N,N'-dimethylformamide or the like. Purification methods include solvent washing and recrystallization.

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.

The compound may have any X-ray diffraction peak.

The vanadium fucrocyanine compound synthesized and purified by the above method is further refined by chemical refining methods such as acid pasting method and acid slurry method, or mechanical grinding method, and used as a charge generating agent. Also,
If necessary during grinding, it is also possible to use grinding aids such as common salt and sulfur sulfate.

Equipment used during grinding includes a kneader, Banbury mixer, attritor, edge runner mill, roll mill, ball mill, and sand mill.

Examples include, but are not limited to, 5PEX mills, homo mixers, dispersers, agitators, show crushers, stamp mills, cutter mills, and micronizers.

The charge generation layer using a vanadium phthalocyanine compound of the present invention is a uniform layer with high light absorption efficiency, and is formed between particles in the charge generation layer, between the charge generation layer and the charge transfer layer, and between the charge generation layer and the undercoat layer. or with less air gap between the conductive substrates,
To obtain an electrophotographic photoreceptor that satisfies many requirements such as properties as an electrophotographic photoreceptor such as potential stability and prevention of rise in bright area potential during repeated use, reduction of two-image defects, and printing durability. be able to.

An n-type photoreceptor is produced 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 vanadium phthalocyanine compound of the present invention can be suitably used for all of the above-mentioned various photoreceptors. The charge generation layer can be obtained by dispersing and coating a vanadium phthalocyanine compound and a resin in an appropriate solvent, but if necessary,
It can also be used by dispersion coating 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, and the crystals have been extremely well-ordered using an appropriate solvent, so impurities that existed between particles can be removed, making it possible to deposit them extremely efficiently. It is also effective as a material for vapor deposition.

The photoreceptor is coated using a spin coater, applicator, spray coater, bar coater, dip coater, doctor blade, roller coater, curtain coater, or bead coater.

Drying is preferably carried out by heating at 40 to 200° C. for 10 minutes to 6 hours under stationary or blowing air conditions. After drying, the film is coated to a thickness of 0.01 to 5 microns, 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,
Polyarylates (condensation polymers of bisphenol A and phthalic acid, etc.), polycarbonate polyesters, phenoxy resins, polyvinyl acetate, acrylic resins, polyacrylamide resins, polyamide resins, polyvinylpyridine, cellulose resins, urethane resins, epoxy resins, silicone resins , polystyrene, polyketone resin, polyvinyl chloride, vinyl chloride copolymer, polyvinyl acetal, polyacrylonitrile, phenol resin, melamine resin, casein, polyvinyl alcohol, polyvinylpyrrolidone, and other insulating resins. The resin contained in the charge generation layer is suitably 100% by weight or less, preferably 40% by weight or less. 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 and undercoat layer, which will be described later, during coating.

Specifically, aromatic hydrocarbons such as benzene, xylene, ligroin, monochlorobenzene, dichlorobenzene,
Ketones such as acetone, methyl ethyl ketone, and cyclohexanone, methanol, and ethanol.

Alcohols such as isopropanol, ethyl acetate.

Esters such as methyl cellosolve, carbon tetrachloride.

Chloroform, dichloromethane, dichloroethane.

Aliphatic halogenated hydrocarbons such as trichlorethylene, ethers such as tetrahydrofuran, dioxane, and ethylene glycol monomethyl ether.

Amides such as N,N-dimethylformamide and N,N-dimethylacetamide, and sulfoxides such as dimethylsulfoxide are used.

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 agent used in the present photoreceptor is preferably a -Noshiro (II') compound, but is not limited to these compounds.

(In the formula, R6 and R7 are hydrogen atoms, alkyl groups, alkoxy groups, or aryl groups, Ra, Rq, and Rho are hydrogen atoms or -NR6 (R7) groups, and n is 0 or 1.) General formula [ As a particularly preferable example of 11), R4゜R5
are both edyl groups and 2 R6-R8 are hydrogen atoms, in other words, any one of R6 to R is NC2H3
(C21(S)).

Further, charge transfer substances can be used alone or in combination of two or more types. Resins used for the charge transfer layer include silicone resin, ketone resin, polymethyl methacrylate,
Polyvinyl chloride, acrylic resin, polyarylate, polyester, polycarbonate.

Polystyrene, acrylonitrile-styrene copolymer, acrylonitrile-butadiene copolymer.

Insulating resins such as polyvinyl butyral, polyvinyl formal, polysulfone, polyacrylamide, polyamide, chlorinated rubber, poly N-vinyl carhadur, polyvinyl anthracene, polyvinyl pyrene, etc. are used.

Coating methods include spin coater and applicator.

Spray coater, bar coater, dip coater.

The coating is carried out using a doctor blade, roller coater, curtain coater, or bead coater, and the film thickness after drying is preferably 5 to 50 microns, preferably 10 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. Nylon 610. Conductive and dielectric particles such as polyamides such as copolymerized nylons and alkoxymethylated nylons, casein, polyvinyl alcohol, nitrocellulose, ethylene-acrylic acid copolymers, geladine, polyurethanes, polyvinyl butyral and silicon, carbon+silicon and carbon Bragg. It can also be adjusted by incorporating it into the resin.

The material of the present invention has an absorption peak at a wavelength of 800 mm or more and 650 nm, and is used not only as an electrophotographic photoreceptor in copying machines and printers (but also in solar cells).

It is also suitable as an absorbing material for 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 10 parts of 3-chlorophthalodinyl I, 10 parts of phthalodinitrile, and 9.6 parts of vanadium pentoxide were added to 200 parts of quinoline.
After reacting at 220° C. for 4 hours, the solvent was removed by steam distillation. Then, it was purified with acetone.

The sample was dried to obtain 21.4 parts of vanadium phthalocyanine compound. The vanadium fucrocyanine compound obtained as a result of elemental analysis had a composition of VOP (, -CI 0.45).

Example 2 A vanadium phthalocyanine compound was prepared in the same manner as in Example 1, except that 10 parts of 3-methoxyphthalodinitrile was used instead of 3-chlorophthalodinitrile, and 20.8 parts were obtained. Results of elemental analysis.

The obtained vanadium phthalocyanine compound is ■OPC
It had a composition of (OCH3) 0.38.

-16= Example 3 Vanadium was prepared in the same manner as in Example 1, except that 10 parts of 2-methyl-1-amino-3-iminoisoindolenine was used instead of 3-chlorophthalodinitrile and phthalodinitrile. 20. Preparing a phthalocyanine compound.
I got 3 copies. As a result of elemental analysis, the obtained vanadium phthalocyanine compound had a composition of vopC(CH3) 0.82.

Next, a method for producing an electrophotographic photoreceptor using the vanadium phthalocyanine compounds produced in Examples 1 to 3 as a charge generating agent will be described.

Copolymerized nylon (Amiran CM-8000 manufactured by Toshi) 10
The coating liquid was mixed with 190 parts of ethanol in a ball mill for 3 hours to dissolve it, and the coating solution 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.
．． A sheet with a 5 micron subbing layer was obtained.

Two parts of the vanadium phthalocyanine compound obtained in this example were dispersed in a ball mill for 6 hours together with tree bile obtained by dissolving 1 part of a vinyl chloride-vinyl acetate copolymer resin (VMCH manufactured by Union Carbide) in 97 parts of THF.

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

A 0.2 micron charge generation layer was formed.

Next, as a charge transfer agent, 1 part of exemplified compound (II-a) of the compound of Noshiro (II), polycarbonate resin (
1 part of Panlite L-1250 (manufactured by Kijin Kasei) was mixed and dissolved with 8 parts of methylene chloride. After this liquid was applied onto the charge generation layer and dried, the electrophotographic properties of the 15 micron charge photoreceptor were measured by the following method.

Static mode 2. Corona zone, 1st province is -5.2K
White light of 5 Lux with a surface potential of 1 V and 1 μW of 8
White light half-reduction exposure sensitivity (El/2) from the time when the amount of charge decreases to 1/2 after irradiating light adjusted to 00r+m
I looked into it. In addition, the 2-spectral sensitivity is determined by corona charging the photoreceptor to -5.2 KV using an electrostatic charging test device.
The light source is a 500W xenon lamp.

It was irradiated with monochromatic light using a monochromator (manufactured by Jobin Yvon), and the light attenuation during charging exposure was measured.

The results of electrophotographic properties are shown in Table 1.

Table 1 Example 4 A vanadium phthalocyanine compound prepared under the same conditions as Example 1 was placed on F) ET film having a subbing layer.
0.15 under vacuum conditions of 10-'Torr. A charge generation layer having a film thickness of c+m was obtained. A charge transfer layer was formed thereon under the same conditions as in Example 1, and the electrophotographic properties were measured. The results are shown in Table 2.

Table 2 Electron = 19 using vanadium phthalocyanine of the present invention
= The photoreceptor with the primary layer had almost the same sensitivity in both the two-dispersion method and the vapor deposition method.

Comparative Examples 1 to 4 Electrophotographic photoreceptors were prepared in the same manner as in Example 1, except that vanadyl phthalocyanine (VOPC) was used as a charge generation agent and the compounds shown in Table 3 were used as charge transfer agents. compared.

Part 2 Table ・ The results of the electrophotographic properties of Comparative Examples 1 to 4 are shown in Table 4.

Table 4 From the results in Table 4, the electrophotographic photoreceptors of Comparative Examples 1 to 4 were as follows:
Compared to Examples 1 to 4, the sensitivity was significantly lower.

Furthermore, Examples 1 to 4. The photoreceptors prepared in Comparative Examples 1 to 4 were left under white light of 600 (lux) for 30 minutes.

The surface potential of the photoreceptor before and after being left standing was measured to compare the optical memory properties.

The results are shown in Table 5.

Table 5 The potential difference was determined using the following formula.

(Potential difference) - (Surface potential before standing) - (Surface potential after standing) From the results in Table 5, Examples 1 to 4 of the vanadium phthalocyanine compound and photoreceptor of the present invention are as follows.

The potential difference before and after the 600 (lux) irradiation was 15 (V) or less, whereas in Comparative Examples 1 to 4, the potential was significantly reduced. Based on the above results, the photoreceptor of the present invention is as follows.

It was confirmed that in addition to excellent 1-spectral sensitivity, it also had stability against light.

Furthermore, the following hathedium phthalocyanine compounds were prepared and their electrophotographic properties were measured (charge transfer agent).

Other conditions were the same as Examples 1 to 4). The results are shown in Table 6.

Table 6 [Effects of the invention] According to the present invention, in addition to excellent exposure sensitivity characteristics and wavelength characteristics,
Deterioration resistance properties during repeated use over long periods of time.

An electrophotographic photoreceptor having rigidity resistance of 1 and image stability could be obtained.

Claims (1)

[Claims] 1. In an electrophotographic photoreceptor comprising a charge generating agent and a charge transfer agent on a conductive support, the charge generating agent is
Vanadium phthalocyanine compounds having a substituent represented by the general formula [I] ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [ I ] (In the formula, R_1 represents a halogen atom, an oxygen atom, a hydroxyl group, a nitro group, and an alkoxy group. , R_2 to R_5 have a substituent such as a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an allyl group, an aryl group, an aryloxy group, a nitro group, a cyano group, a hydroxyl group, a benzyloxy group, an amino group, but R_2 to R_5 cannot all be hydrogen atoms. j is an integer of 1 or 2, and k, l, m and n are 0
Represents the number ~4. ) An electrophotographic photoreceptor characterized by: 2. An electrophotographic photoreceptor comprising a charge generation layer and a charge transfer layer laminated on a conductive support, wherein the charge generation agent is the vanadium phthalocyanine compound according to claim 1. . 3. In an electrophotographic photoreceptor comprising a charge generation layer and a charge transfer layer laminated on a conductive support, the charge generation agent is the vanadium phthalocyanine compound according to claim 1,
An electrophotographic photoreceptor, wherein the charge transfer agent is a compound represented by the general formula [II]. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [II] (In the formula, R_6 and R_7 are hydrogen atoms, alkyl groups, alkoxy groups, or aryl groups, R_8, R_9, R_1_
0 represents a hydrogen atom or -NR_6(R_7) group, n
is 0 or 1. 4. The electrophotographic photoreceptor according to claim 2 or 3, comprising an inorganic or organic subbing layer on the conductive support.