JPS61228450A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To enable a sharp image to be formed by forming a photosensitive layer contg. a specified aromatic amino compd. as an effective component on a conductive substrate. CONSTITUTION:The photosensitive body is obtained by forming a photosensitive layer 2' prpared by dispersing an electrostatic charge generating material 3 into a charge generating medium 4 composed of the aromatic amino compd. represented by formula I and a binder on the conductive substrate 1, and said amino compd. has almost no absorption in the visible region and the charge generating material for generating charge carriers generally has absorption in the visible region and both of the absorption region do not overlap each other mainly in the visible region. When the amino compd. is combined with the charge generating material, it functions especially effectively as a charge transfer material.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to an electrophotographic photoreceptor, and more particularly to an electrophotographic photoreceptor containing a specific aromatic amino compound in its photosensitive layer.

Prior Art Conventionally, inorganic materials such as selenium, cadmium sulfide, and zinc oxide have been used as photoconductive materials for photoreceptors used in electrophotography. The "electrophotographic method" referred to here generally means that a photoconductive photoreceptor is first photographed in a dark place.
For example, it is charged by corona discharge, then imagewise exposed to selectively dissipate the charge only in the exposed area to obtain an electrostatic latent image. This is one of the image forming methods in which an image is formed by developing and visualizing electrostatic fine particles (toner) composed of a binder.

The basic characteristics required of a photoreceptor in such electrophotography are 1) ability to be charged to an appropriate potential in a dark place, 2) less charge dissipation in a dark place, and 3)
For example, the charge can be quickly dissipated by light irradiation.

Incidentally, it is a fact that each of the above-mentioned inorganic substances has many advantages, but also has various disadvantages. For example, selenium, which is currently widely used, fully satisfies conditions 1) to 3) above, but the manufacturing conditions are difficult, the manufacturing cost is high, and it is not flexible.
It also has drawbacks such as being difficult to process into a belt shape and requiring care in handling because it is sensitive to heat and mechanical shock.

Cadmium sulfide and zinc oxide are used as photoreceptors by being dispersed in a resin as a binder, but they cannot be used as is because of mechanical drawbacks such as smoothness, hardness, tensile strength, and abrasion resistance. cannot be used.

In recent years, electrophotographic photoreceptors using various organic materials have been proposed in order to eliminate the drawbacks of these inorganic materials, and some of them have been put into practical use. For example, poly-N-vinylcarbazole and 2,4,7-dolinitrofluorene-9
- photoreceptor (U.S. Pat. No. 3,484,237)
1), a photoreceptor made by sensitizing poly-N-vinylcarbazole with a biryllium base dye (Japanese Patent Publication No. 48
-25658), a photoreceptor whose main component is an organic pigment (described in JP-A-47-37543), a photoreceptor whose main component is a eutectic complex consisting of a dye and a resin (described in JP-A-47-37543), a photoreceptor whose main component is a eutectic complex consisting of a dye and a resin 47-10735). Although these photoreceptors have excellent properties and are considered to be of high practical value, considering the various requirements for photoreceptors in electrophotography, it is still difficult to fully meet these requirements. The reality is that we are not getting anything that satisfies us.

However, the photoreceptors mentioned above all differ depending on the purpose or manufacturing method, but generally speaking, good characteristics can be obtained by using an excellent photoconductive material.

Purpose An object of the present invention is to provide a photoreceptor that can overcome the various drawbacks of the conventional photoreceptors mentioned above and fully satisfy the conditions required in electrophotography. Another object of the present invention is to provide an electrophotographic photoreceptor that is easy to manufacture, relatively inexpensive, and has excellent durability.

As a result of research and consideration on many photoconductive substances, the present inventor found that the following general formula [wherein X is an oxygen atom or a sulfur atom, R1 and R2 are hydrogen or a lower alkyl group, Represents a lower alkoxy group or a halogen atom. It has been found that an aromatic amino compound represented by the following formula works effectively as a photoconductive substance for an electrophotographic photoreceptor.

Examples of the lower alkyl group in R1 and R2 include methyl, ethyl, propyl, and butyl; examples of the lower alkoxy group include methoxy, ethoxy, propoxy, and butoxy; and examples of the halogen atom include chlorine and bromine.

As will be clear from the description below, this aromatic amino compound is
They have also discovered that they can be combined with a variety of materials to create photoreceptors with unexpected effects.

The present invention was completed based on these findings.

That is, the present invention provides an electrophotographic photoreceptor in which a photosensitive layer is provided on a conductive support.
It is characterized by containing an aromatic amine compound represented by I).

° The aromatic amino compound represented by the general formula (I) used in the present invention has the following general formula % formula % () [where X is an oxygen atom or a sulfur atom, and R1 is hydrogen, a lower alkyl group, a lower Represents an alkoxy group or a halogen atom. ) and the following general formula (rV
) [In the formula, Y represents a halogen atom, and R2 represents hydrogen, a lower alkyl group, a lower alkoxy group, or a halogen atom. )
It can be obtained by reacting with a halobenzene derivative represented by

Aromatic amino derivative (I) of the present invention comprises amino compounds represented by general formulas (I) and (II) and general formula (IV
) with a basic catalyst in the presence of a copper catalyst at a temperature of about 100°C to 250°C. Examples of the basic catalyst include caustic soda, caustic potash, anhydrous sodium carbonate, anhydrous potassium carbonate, and the like.

Examples of the copper catalyst include copper powder, copper oxide, and copper halides such as copper bromide and copper iodide.

The reaction may be carried out without a solvent or with a solvent. The reaction solvents used include benzene solvents such as toluene, xylene, chlorobenzene, 0-dichlorobenzene, and nitrobenzene, N,N-dimethylbormamide, N
-Methylpyrrolidone, 1,3-dimethyl-2-imidazolidinone, dimethylsulfoxide, and the like. Among them, polar solvents such as nitrobenzene, 1,3
-dimethyl-2-imidazolidinone and dimethyl sulfoxide are preferred.

The reaction temperature is determined by 1) stability of the solvent used against basic catalysts, 2) general formulas (II), (III) and (
The compound can be selected from a wide range depending on the reactivity of the compound (TV) and 3) reactivity as a condensing agent in the basic catalyst. For example, when using a polar solvent, the temperature is actually 100°C to 250°C, preferably 150°C to 250°C.
It is ℃.

However, higher temperatures may be used if the reaction time is shortened or a less active condensing agent is used.

A specific example of production is as follows.

Production Example: In a 500 mj2 round bottom flask equipped with a stirrer,
4,4--diaminodiphenyl ether 20.0 (+
(0.1 mol), 4-iodo-1-luene 87.2 (0
, 4 mol), anhydrous potassium carbonate 55.3 g (0.4 mol), copper powder 1. Og and 200 tJ2 of nitrobenzene were charged. This mixture was heated and stirred at 200 to 210° C. for 8 hours while removing water by azeotropy.

After the reaction, remove anhydrous potassium carbonate and copper powder by filtration.
The nitrobenzene is then removed by steam distillation,
The residual oil was dissolved in toluene and the toluene solution was dried over anhydrous magnesium sulfate.

After distilling off the toluene, this brown mixture was separated by column chromatography using silica gel (Wako Gel C-200) 500Q and cyclohexane (eluent) to obtain pale yellow crystals 3G and 7Q (yield 65.5%). Obtained. Recrystallized from a mixed solvent of ethyl acetate and ethanol to obtain 4.4-
A pure product of -bis(N,N-diP-)-lylamino)diphenyl ether was obtained. Melting point 134.0~6.0℃
Met.

Specific examples of the naphthalene compound represented by the general formula (I) thus obtained are shown in Table 1 below.

The photoreceptor of the present invention comprises one of the above-mentioned aromatic amino compounds.
The photosensitive layer contains one or more aromatic amino compounds, and depending on how these aromatic amino compounds are applied,
It can be used as shown in FIG. 2 or 3.

The photoreceptor shown in FIG. 1 has a photoreceptor 1i12 comprising an aromatic amino compound, a sensitizing dye, and a binder (binder resin) on a conductive support 1. The photoreceptor shown in FIG. The aromatic amine compound here acts as a photoconductive substance, and the generation and transfer of charge carriers necessary for light attenuation take place via the aromatic amine compound. However, aromatic amine compounds have almost no absorption in the visible region of light, so in order to form images with visible light, it is necessary to sensitize them by adding a sensitizing dye that absorbs in the visible region. There is.

The photoreceptor shown in FIG. 2 has a photosensitive layer 2' on a conductive support 1 in which a charge generating substance 3 is dispersed in a charge transporting medium 4 made of an aromatic amine compound and a binder. It is something that was given.

The aromatic amine compound here forms the charge transport medium 4 together with the binder (or binder and plasticizer), while the charge generating substance 3 (such as an inorganic or organic pigment)
generates charge carriers. In this case, the charge transport medium 4 is mainly responsible for receiving charge carriers generated by the charge generating substance 3 and transporting them.

The basic condition for this photoreceptor is that the absorption wavelength regions of the charge generating substance and the aromatic amine compound do not overlap with each other, mainly in the visible region. This is because in order to efficiently generate charge carriers in the charge generation material 3, it is necessary to transmit light to the surface of the charge generation material. Are aromatic amino compounds represented by general formula (I) allowed? l! There is almost no absorption in the area, and is it generally OK? Its feature is that it works particularly effectively as a charge transport material when combined with a charge generation material 3 that absorbs light in the I region and generates charge carriers.

The photoreceptor in FIG. 3 is a photoreceptor W12 consisting of a conductive support 1, a charge generation layer 5 mainly composed of a charge generation substance 3, and a charge transport layer 4 containing an aromatic amino compound.
In this photoreceptor, light transmitted through the charge transport layer 4 reaches the charge generation layer 5, and charge carriers are generated in that region. The charge carriers required for light attenuation are generated by a charge generation substance 3, and the charge carriers are transported by a charge transport layer 4 (mainly composed of an aromatic amine compound). This mechanism is similar to that described for the photoreceptor shown in FIG.

In order to actually produce the photoreceptor of the present invention, in the case of the photoreceptor shown in Figure 1, one or more aromatic amino compounds are dissolved in a solution containing a binder, and then added to the solution. The photosensitive layer 2 may be formed by preparing a liquid containing an infectious agent, coating the liquid on the conductive support 1, and drying it.

The thickness of the photosensitive layer is 3 to 50 μm, preferably 5 to 2 μm.
0 μl is appropriate. The amount of the aromatic amino compound in the photosensitive layer 2 is 30 to 70% by weight, preferably about 50% by weight, and the amount of the sensitizing dye in the photosensitive layer 2 is 0.1 to 70% by weight.
b is preferably 0.5 to 3% by weight. Infectious agents include triarylmethane dyes such as Brilliant Green, Victoria Blue 81 Methyl Violet, Crystal Violet, Acid Violet 6B, Rhodamine B10-Damine 6G, Rhodamine G Extra, Eosin S1 Erythrosin, Rose Vecigal, and Fluorescein. xanthine dyes, thiazine dyes such as methylene blue, cyanine dyes such as cyanine, 2.6-
Diphenyl-4-(N,N-dimethylaminophenyl)
Thiapyrylium verchlorate, benzobyrylium salt (
Examples include biryllium dyes such as those described in Japanese Patent Publication No. 4G-25658. Note that these sensitizing agents may be used alone or in combination of two or more.

In addition, in order to produce the photoreceptor shown in FIG. The photosensitive layer 2' may be formed by coating it on the support 1 and drying it.

The thickness of the photosensitive layer 2- is 3 to 50 μm, preferably 5 to 20 μm.
μm is appropriate. The aromatic amino compound m in the photosensitive layer 2- is 10 to 95% by weight, preferably 30 to 90% by weight, and the photosensitive layer 2- is 10 to 95% by weight, preferably 30 to 90% by weight. The amount of the charge generating substance 3 in J2' is 0.1 to 50% by weight, preferably 1 to 20% by weight. As the charge generating substance 3, for example, selenium,
Ia-free pigments such as selenium-tellurium, cadmium sulfide, cadmium-selenium sulfide, and α-silicon; examples of organic pigments include CI Pigment Blue 25 (Color Index CI 21180), CI Pigment Red 41 (CI 21200), and CI Acid Red 52. (Cr 45100), CI Basic Red 3 (CI 45210), an azo pigment having a carbazole skeleton (described in JP-A No. 53-95033), an azo pigment having a disdyrylbenzene skeleton (described in JP-A-53-133445) ), an azo pigment having a triphenylamine skeleton (JP-A-53-132347)
M), an azo pigment having a dibenzothiophene skeleton (described in JP-A No. 54-21728), an azo pigment having an oxadiazole skeleton (described in JP-A No. 54-127)
42, an azo pigment having a fluorenone skeleton (described in JP-A No. 54-22834), an azo pigment having a bisstilbene skeleton (described in JP-A-54-17733),
Azo pigments having a distyryl oxadiazole skeleton (described in JP-A-54-2129), azo pigments having a distyrylcarbazole skeleton (described in JP-A-54-2129),
Azo pigments such as C.I. Pigment Blue 16 (CI-74100), indigo pigments such as C.I. Butt Brown 5 (CI 73410) and C.I. Butt Dye (CI 73030); Pigments, perylene pigments such as Argo Scarlet B (manufactured by Bayer) and Indus Thread Scarlet R (manufactured by Bayer). Note that these charge generating substances may be used alone or in combination of two or more types.

Furthermore, in order to produce the photoreceptor shown in FIG. 3, the charge generating substance 3 is vacuum-deposited on the conductive support 1, or fine particles of the charge generating substance 3 are deposited in a suitable solvent in which a binder is dissolved if necessary. Apply the dispersion liquid dispersed in it, dry it,
Furthermore, if necessary, surface finishing and film thickness adjustment were performed by methods such as puff polishing to form a charge generation layer 5, on which one or more aromatic amine compounds and a binder were dissolved. The charge transport layer 4 may be formed by applying a solution and drying it. The charge generating material 3 used to form the charge generating layer 5 here is the same as that used in the description of the photosensitive layer 2'.

The thickness of the charge generation layer 5 is preferably 5 μm or less, preferably 2 μm or less, and the thickness of the charge transport layer 4 is suitably 3 to 50 μm, preferably 5 to 20 μm. If the charge generation layer 5 is of a type in which fine particles of the charge generation substance 3 are dispersed in a binder, the proportion of the fine particles of the charge generation substance 3 in the charge generation layer 5 is preferably 10 to 95% by weight. It is about 50 to 90% by weight. Further, the amount of the aromatic amino compound in the charge transport layer 4 is preferably 10 to 95% by weight, preferably 30 to 90% by weight.
Weight%.

In the production of these photoreceptors, the conductive support 1 is made of a metal plate or metal foil such as aluminum, a plastic film on which metal such as aluminum is vapor-deposited, or
Paper that has been subjected to conductive treatment is used. In addition, as a binder, synthetic resins such as polyamide, polyurethane, polyester, epoxy resin, polyketone, polycarbonate, polyvinyl ketone, polystyrene, poly-N-
Vinyl polymers such as vinyl carbazole and polyacrylamide are used, but any insulating and adhesive resin can be used. If necessary, plasticizers are added to the binder; such plasticizers include halogenated paraffins, polychlorinated biphenyls, dimethylnaphthalene,
Examples include dibutyl phthalate.

Furthermore, in the photoreceptor obtained as described above, a contact WJi or barrier layer can be provided between the conductive support and the photosensitive layer, if necessary. Materials used for these layers include polyamide, nitrocellulose, aluminum oxide, etc., and the film thickness is preferably 1 μm or less.

To make a copy using the photoreceptor of the present invention, the photoreceptor surface is charged, exposed to light, developed, and, if necessary, transferred to paper or the like.

The photoreceptor of the present invention has excellent advantages such as high sensitivity and flexibility.

Examples are shown below. In the following examples, all parts are by weight.

Example 1 76 parts of Diane Blue (CI Pigment Blue 25, CI 21180) and 2 parts of polyester resin (Vylon 200, manufactured by Toyobo Co., Ltd.) were used as charge generating substances.
% tetrahydrone furan solution and 3,700 parts of tetrahydrofuran were pulverized and mixed in a ball mill, and the resulting dispersion was dofted onto the aluminum surface of a conductive support made of an aluminum-deposited polyester base.
It was applied using a blade and air-dried to form a charge generation layer with a thickness of about 1 μm.

On the other hand, as a charge transport substance, 2 parts of No. 2 aromatic amino compound, polycarbonate resin (Panlite K 130
0, manufactured by Konjin Co., Ltd.) 2 parts and tetrahydrofuran 1
After mixing and dissolving 6 parts to form a solution, this was applied onto the charge generation layer using a doctor blade, and dried at 80°C for 2 minutes and then at 105°C for 5 minutes to form a charge transport layer with a thickness of about 20 μm. Photoreceptor No. was formed by forming a layer.

1 was created.

Examples 2 to 18 Photoreceptors N002 to 18 were prepared in exactly the same manner as in Example 1, except that the charge generating substance and the charge transporting substance (aromatic amino compound) were replaced with those shown in Table 2.

Table 2 Example 19 On an aluminum plate having a thickness of about 300 μm, selenium was vacuum-deposited to a thickness of about 1 μm to form a charge generation layer. Next, 2 parts of No. 10 aromatic amine compound, polyester resin (Polyester Adhesive 4900 manufactured by DuPont)
0) Mix 3 parts and 45 parts of tetrahydrofuran,
Dissolve to create a charge transport layer forming liquid, apply this onto the charge generation layer (selenium vapor deposited layer) using a doctor blade, air dry, and then dry under reduced pressure to a thickness of about 10 cm.
The photoreceptor N of the present invention is formed by forming a charge transport layer of μm.
0019 was obtained.

Example 20 A charge generation layer (however, the thickness was approximately 0.3 μm) was formed using a perylene pigment instead of selenium, and an aromatic amino compound was used as No.
Photoconductor No. 0938 was used in exactly the same manner as in Example 19.

20 were created.

Example 21 A mixture of 1 part of Diane Blue (same as that used in Example 1) and 158 parts of tetrahydrofuran was ground and mixed in a ball mill, and to this was added 12 parts of No. 51 aromatic amino compound, A photosensitive layer forming solution obtained by adding 18 parts of polyester resin (Polyester Adhesive 49000 manufactured by DuPont) and further mixing was applied onto an aluminum vapor-deposited polyester film using a doctor blade, and dried at 100°C for 30 minutes. Approximately 16μ thick
photoreceptor No.2 of the present invention by forming a photoreceptor layer of
1 was created.

Photoreceptors No. 1 to 21 thus produced were tested using a commercially available electrostatic copying paper tester (3p4 manufactured by KK Kawaguchi Electric Seisakusho).
28 type), conduct a corona discharge of 16KV or +6KV for 20 seconds to cool down the charge, leave it in a dark place for 20 seconds, measure the surface potential Vpo (volt) at that time, and then expose it to tungsten lamp light. Irradiate the body surface so that the illuminance is 4.5 lux, and the surface potential is 1/1 of Vpo.
Find the time (seconds) it takes to reach 2, and calculate the exposure IE 1/2
(looks/seconds) was calculated. The results are shown in Table-3.

In addition, after each of the photoreceptors described above is charged using a commercially available electrophotographic copying machine, light is irradiated through the original image to form an electrostatic latent image, and the image is developed using a dry developer. When the image (toner image) was electrostatically transferred onto plain paper and fixed, a clear transferred image was obtained. A similarly clear transferred image was obtained when a wet developer was used as the developer.

Effects As described above, the photoreceptor of the present invention has the general formula (I)
By using the aromatic amino compound represented by the formula, the conditions required for a photoreceptor are fully satisfied and clear images are formed.

[Brief explanation of drawings]

1, 2, and 3 are cross-sectional views enlarged in the thickness direction of an electrophotographic photoreceptor according to the present invention. 1... Conductive support, 2.2-. 2"...photosensitive layer,
3... Charge generating substance, 4... Charge transporting medium or charge transporting layer, 5... Charge generating layer. Patent applicant Rico Co., Ltd. - Agent Patent attorney Hide Komatsu Agent Patent attorney Hiroshi Asahi Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] (1) An electrophotographic photoreceptor comprising, on a conductive support, a photosensitive layer containing at least one aromatic amino compound represented by the following general formula (I) as an active ingredient. ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(I) [In the formula, X represents an oxygen atom, a sulfur atom, and R_1 and R_2 represent hydrogen, a lower alkyl group, a lower alkoxy group, or a halogen atom. ]