JPS61143765A - Photosensitive body - Google Patents

Abstract

PURPOSE:To improve solvent solubility of a pigment, to enhance electrostatic characteristics, such as photosensitivity and charge retentivity, and to improve red reproducibility by incorporating a specified perylene pigment in a photosensitive layer. CONSTITUTION:The photosensitive layer contains N,N'-bis(di-tert-butyl phenyl)-3,4,9,10-perylenedicarbox-yimi-de. The use of such a perylene pigment as the photoconductor of the photosensitive body or the use of it for the charge generating layer of a functionally separated photosensitive body by using its charge generating ability permit the obtained photosensitive body to be superior in electrophotographic characteristics, such as charge retentivity, sensitivity, residual potential resistance, and stabilized in characteristics at the time of repeated uses, superior also in red reproducibility, and solvent solubility of the pigment, and accordingly, a uniform good coating film to be easily obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a photoreceptor having a photosensitive layer containing a novel perylene pigment.

BACKGROUND OF THE INVENTION Inorganic photoconductive materials such as lyselene, cadmium sulfide, and zinc oxide have been known as materials constituting the photosensitive layer of a photoreceptor.

These photoconductive materials have many advantages, such as being able to be charged to an appropriate potential in the dark, having little charge dissipation in the dark, and being able to rapidly dissipate charge when irradiated with light. On the other hand, it has various drawbacks. For example, selenium-based photoreceptors require difficult manufacturing conditions, are expensive to manufacture, and are sensitive to heat and mechanical shock, so care must be taken when handling them. With cadmium sulfide photoreceptors and zinc oxide photoreceptors, stable sensitivity cannot be obtained in humid environments, and the dyes added as sensitizers cause charging deterioration due to corona charging and photobleaching due to exposure, so they cannot be used for long periods of time. It has the disadvantage that it cannot provide stable characteristics.

On the other hand, various organic photoconductive polymers including polyvinylcarbazole have been proposed. Although these polymers are superior to the aforementioned inorganic photoconductive materials in terms of film formability and light weight, However, they are still inferior to inorganic photoconductive materials in terms of sufficient sensitivity, durability, and stability against environmental changes.

In recent years, various research and developments have been carried out to solve the drawbacks and problems of these photoreceptors. Photoreceptors of functionally separated type or dispersion type have been proposed.

These functionally separated photoreceptors have a wide range of materials to choose from, and can be made into high-performance photoreceptors by combining the best materials in terms of electrophotographic properties such as charging characteristics, sensitivity, residual potential, repeatability, and printing durability. can be provided. Moreover, since it can be produced by coating, it is possible to provide a photoreceptor with extremely high productivity and at low cost, and furthermore, by appropriately selecting the charge generating material, the wavelength range to which it is sensitive can be freely controlled. For example, organic pigments and dyes such as phthalocyanine pigments, cyanine dyes, polycyclic quinone pigments, perylene pigments, indigo dyes, thioindigo dyes, and methine squaric acid dyes are known as charge-generating materials.

However, even with such photoreceptors, it is not easy to obtain one that satisfies all electrostatic properties, and in particular it is difficult to obtain one that has good sensitivity properties and red color reproducibility. There are few products with excellent properties, and there are drawbacks such as the inability to obtain high-quality photoconductive coatings.

Problems to be Solved by the Invention The present invention has been made in view of the above-mentioned facts, and its purpose is to have excellent overall electrostatic properties, particularly high photosensitivity, good red reproducibility, and high charge resistance. An object of the present invention is to provide a photoreceptor with excellent solvent solubility of a generated material.

The photoreceptor according to the present invention is characterized by having a photosensitive layer containing a perylene pigment represented by the following general formula CI).

That is, N,N/-bis(di-tert-butylphenyl)-3,4,! , 10-perylene dicarboximide.

In the present invention, by using the perylene pigment represented by the general formula [I] as a photoconductive substance of a photoreceptor, or by utilizing only the excellent charge generation ability of the perylene pigment of the present invention, By using the photoreceptor in the charge generation layer of a separate photoreceptor, it is possible to create a photoreceptor that has excellent electrophotographic properties such as charge retention ability, sensitivity, and residual potential, and that exhibits stable characteristics even when subjected to repeated use. I can do it.

The photoreceptor of the present invention has a photosensitive layer containing one or more perylene pigments represented by the above general formula. Various types of photoreceptors are known, and the photoreceptor of the present invention may be any of them. For example, there are single-layer photoreceptors in which a photosensitive layer consisting of a perylene pigment dispersed in a resin binder or a charge transport medium is provided on a support, and a charge generation layer containing a perylene pigment as a main component is provided on a support. The perylene pigment of the present invention, which has a so-called laminated photoreceptor having a charge transport layer thereon, acts as a photoconductive substance,
When light is absorbed, charge carriers are generated with extremely high efficiency, and the generated charge carriers can be transported using perylene pigment as a medium, but it is more effective to transport them using a charge transport material as a medium.

To prepare a single-layer type photoreceptor, fine particles of perylene pigment may be dispersed in a resin solution or a solution containing a charge transport compound and a resin, and this may be coated on a conductive support and dried. The thickness of the photosensitive layer at this time is preferably 3 to 30 microns, preferably 5 to 20 microns. If the amount of perylene pigment used is too small, the sensitivity will be poor, and if it is too large, the charging property will be poor.
The strength of the photosensitive layer may be weakened, and the proportion of pigment in the photosensitive layer may be 0.01 to 2 parts by weight, preferably 0.05 to 1 part by weight, based on 1 part by weight of resin. The proportion of the charge transport material to be added is 0.1 parts by weight of the resin.
The range is 2 parts by weight, preferably 0.2 to 12 parts by weight. Also, in the case of charge transport materials such as polyvinylcarbazole, which can themselves be used as binders,
The amount of perylene pigment added is preferably 0.01 to 0.05 parts by weight per 1 part by weight of the charge transport material.

To create a laminated photoreceptor, a perylene pigment is vacuum deposited on a conductive support, or it can be dissolved in a solvent such as an amine and coated, or the pigment can be coated with a suitable solvent or a binder resin if necessary. It is obtained by applying and drying a coating liquid prepared by dispersing it in a solution in which a charge transporting material and a binder are dissolved, and then applying and drying a solution containing a charge transporting material and a binder thereon. The thickness of the perylene pigment layer serving as the charge generation layer at this time is preferably 4 microns or less, preferably 2 microns or less, and the thickness of the charge transport layer is 3 to 30 microns, preferably 5 to 20 microns. The proportion of the charge transport material in the charge transport layer is 0.2 to 2 parts by weight, preferably 0.3 to 1.3 parts by weight, per 1 part by weight of the binder resin. For polymeric charge transport materials that can be used as binders themselves, no other binder is used (
But it's okay.

In addition to the binder resin, the photoreceptor of the present invention contains plasticizers such as halogenated halaffin, polychlorinated biphenyl, dimethylnaphthalene, dibutyl phthalate, 0-terphenyl, chloranil, tetracyanoethylene, 2,4.7-trinitro, 9- Electron-withdrawing sensitizers such as fluorenone, 5,6-dicyanopenzoquinone, tetracyanodimethane, tetrachlorophthalic anhydride, 3,5-dinitrobenzoic acid, methyl violet, rhodamine B1 cyanine dye, pyrylium salt, thiapyrylium salt, etc. A sensitizer may also be used. The perylene pigment of the present invention, unlike other perylene pigments, can be dissolved in l) MF and the like. Therefore, it does not require equipment such as vacuum evaporation, and it can be made into fine particles without being dispersed with a resin, making it possible to efficiently generate electric charges.

Examples of perylene pigments used in the present invention include 3,
By reacting 4,9.10-perylenetetracarboxylic acid with 2,5-di-tert-butylaniline, N-N'-bis(2,5-di-tert-butylphenyl)-3,4, 9,10-perylene dicarboximide is obtained. Such perylene pigments include other known perylene pigments (for example, CI Nα71330, Nα711
Unlike 40), it easily dissolves in dimethylformamide and amines. Therefore, a uniformly good coating film can be easily obtained, the overall characteristics of the photoreceptor are improved, and the manufacturing process is simpler than vapor deposition or the like.

As the electrically insulating binder resin used in the present invention, electrically insulating binders such as thermoplastic resins, thermosetting resins, photocurable resins, and photoconductive resins that are known per se can be used. Examples of suitable binder resins include, but are not limited to, saturated polyester resins, polyamide resins, acrylic resins, ethylene-vinyl acetate copolymers, ionically crosslinked olefin copolymers (ionomers).
Thermoplastic binders such as styrene-butadiene block copolymer, polycarbonate, vinyl chloride-vinyl acetate copolymer, cellulose ester, polyimide, styrene resin; epoxy resin, urethane resin, silicone resin, phenol resin, melamine resin, xylene Thermosetting binders such as resins, alkyd resins, and thermosetting acrylic resins; photocurable resins; photoconductive resins such as poly-N-vinylcarbazole, polyvinylpyrene, and polyvinylanthracene. These can be used alone or in combination. These electrically insulating resins were measured individually and
It is desirable to have a volume resistance of ×lOΩ·α or more.

Further, charge transport materials that can be used in the present invention include, for example, carbazole, N-ethylcarbazole, N-vinylcarbazole, N-isopropylcarbazole, N-phenylcarbazole, tetracene, chrysene, pyrene, perylene, 2-phenylnaphthalene, azapyrene. , 2.3-pentucrysene, 3.4-benzopyrene, fluorene, 12-benzofluorene, 2.3-benzofluorene, 4-(2-fluorenone-a-zo)resorcinol, 4-(2-fluorenylazo)m-cresol, 2-P-anisoleaminofluorene P-diethylamino-azobenzene, 1-(2-thiazolyl azo)
-2-naphthol, 4-anisoleami/azobenzene, cation, N,N-dimethyl-P-phenylazoaniline, .P-(dimethylamino)stilbene, 1.4-
Bis(2-methylstyryl)benzene, 9-(4-diethylaminostyryl)anthracene, 2.5-bis(4
-diethylaminophenol) -1,3,s-oxadiazole, l-phenyl-3-(P-diethylaminostyryl)-5-(p-diethylaminophenyl)hylasoline, 1-phenyl-3-methyl-5-pyrazolone and 2 Examples include -(m-naphthyl)-3-phenyloxazole and p-diethylaminobenzaldehyde (diphenylhydrazone).

Effects of the Invention The photoreceptor according to the present invention has excellent overall electrostatic properties such as photosensitivity and charge retention ability, good red reproducibility, and excellent solvent solubility of pigments.

Examples will be described below.

Example 1 1 part by weight of the perylene pigment of the above formula is dissolved in 20 parts by weight of dimethylformamide and deposited on an aluminum substrate at about 0.5 parts by weight.
A charge generation layer of 5μ was formed. Next, 10 parts by weight of polycarbonate resin C (manufactured by Banjin Kasei) and 3 parts by weight of polyester resin (manufactured by Toyobo) were mixed with 100 parts by weight of tetrahydrofuran and toluene solvent, the weight factor of the solvent being 9:1. Next, p-diethylaminobenzaldehyde (diphenylhydrazone)
9 parts were added along with 0.01'Lm part of silicone oil. This liquid was coated on the charge generation layer to a thickness of about 15 μm and dried at 80° C. to form a charge transport layer, thereby obtaining a laminated photoreceptor.

Example 2 Example. A charge generation layer was formed in the same manner as in . Next, 20 parts by weight of polycarbonate resin was dissolved in 150 parts by weight of tetracarbonate resin, and 1-phenyl-3-(p-'
/ethylaminostyryl)-5-(p-diethylaminophenyl)-2-pyrazoline was added together with 12 parts and 0.02 parts by weight of silicone oil. This liquid was applied to the charge generation layer 2 to a thickness of about 15 μm and dried at 80° C. to form a charge transport layer, thereby obtaining a laminated photoreceptor.

Example 3 A charge generation layer was formed in the same manner as in Example 1. Next, 10 parts by weight of polycarbonate resin and 150 parts by weight of polyester furan:toluene (9:1) were dissolved. 9 in this
12 parts of -(4-diethylaminostyryl)anthracene were added together with 0.02 parts by weight of silicone oil. This liquid was applied onto the charge generation layer to a thickness of about 15 μm to form a charge generation layer, thereby obtaining a laminated photoreceptor.

Example 4 2 parts by weight of the perylene pigment, 8 parts by weight of polyester resin (manufactured by Toyobo) and 5 parts by weight of N-phenylcarbazole-3-carbaldehyde-diphenylhydrazone in Example 1 were placed in a 500 d beaker with 50 parts by weight of dimethylformamide. A charge generation layer was formed by sonic application, and a single-layer photoreceptor was obtained.

Each photoreceptor was installed in a transfer type copying machine (Ep-310 manufactured by Minolta Camera Co., Ltd.), a DC voltage of -6.OKV (+6.OKV in Example 4) was applied, and the electrostatic characteristics were measured. The results are shown in Table 1, where Vo is the initial surface potential (V), DDR1 is the decay rate (%) of the potential after being left in the dark for 1 second after charging, and E[ is the initial surface potential force. This is the amount of exposure (ffux, 5ec) required to achieve this.

As is clear from this, the photoreceptor containing the perylene pigment according to the present invention has excellent photosensitivity and charge retention ability. Also, when a red image was copied using each photoreceptor, a clear copy was obtained.

Claims (1)

[Scope of Claims] 1. A photoreceptor characterized by having a photosensitive layer containing a perylene pigment represented by the following general formula [I]. ▲There are mathematical formulas, chemical formulas, tables, etc.▼〔I〕