JPH0833663B2 - Electrophotographic photoreceptor - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electrophotographic photoreceptor, and more particularly to an electrophotographic photoreceptor having a photosensitive layer containing a specific amino compound.

2. Description of the Related Art Conventionally, inorganic materials such as selenium, cadmium sulfide, and zinc oxide have been used as photoconductive materials for photoconductors used in electrophotography. The term "electrophotographic method" generally means that a photoconductive photoconductor is first charged in a dark place by, for example, corona discharge, and then imagewise exposed to selectively dissipate the charge only in the exposed portion. An electrostatic latent image is obtained, and this latent image portion is developed with electroscopic fine particles (toner) composed of a coloring material such as a dye or pigment and a binder such as a polymer substance to be visualized to form an image. This is one of the image forming methods.

The basic characteristics required for a photoconductor in such an electrophotographic method are (1) being capable of being charged to an appropriate potential in a dark place, (2) being less in dissipation of a charge in a dark place, (3) It is possible to rapidly dissipate the electric charge by light irradiation.

By the way, it is a fact that each of the above-mentioned inorganic substances has many advantages and, at the same time, has various drawbacks. For example, selenium, which is widely used at present, sufficiently satisfies the above conditions (1) to (3), but the manufacturing conditions are difficult, the manufacturing cost is high, the selenium is not flexible, and it is processed into a belt shape. It is difficult to handle, and it is sensitive to heat and mechanical shocks, so it requires careful handling. Cadmium sulfide and zinc oxide are used as photoconductors by dispersing them in a resin as a binder, but since they have mechanical defects such as smoothness, hardness, tensile strength and abrasion resistance, they can be repeated as they are. Can not be used.

In recent years, electrophotographic photoreceptors using various organic substances have been proposed to eliminate the drawbacks of these inorganic substances, and some of them have been put to practical use. For example, poly-N-vinylcarbazole and 2,4,7-trinitrofluorene-9-
And a photoconductor (described in US Pat. No. 3,484,237), a photoconductor obtained by sensitizing poly-N-vinylcarbazole with a pyrylium salt dye (described in JP-B-48-25658), organic Photoreceptor mainly containing pigment
-37543), and a photoconductor (described in JP-A-47-10735) containing a eutectic complex composed of a dye and a resin as a main component. These photoconductors have excellent properties and are considered to be of high value practically.However, in consideration of various demands on the photoconductor in the electrophotographic method, these demands are still insufficient. It is the actual situation that nothing satisfying the above is obtained.

However, all of the above-mentioned photoreceptors have good characteristics by using an excellent photoconductive substance, although there are differences depending on the purpose or the production method. .

The present inventors have studied many photoconductive materials,
As a result of examination, an amino compound represented by the following general formula (I) (Wherein R ¹ represents a hydrogen atom, an alkyl group, an alkoxy group, an aryloxy group or a halogen atom, R ^{2 a} hydrogen atom, an alkyl group containing a substituted alkyl group or a substituted or unsubstituted phenyl group, R ³ and R ⁴ Represents an alkyl group, an aralkyl group or an aryl group, and Ar represents an aromatic hydrocarbon.) It was found that the amino compound effectively acts as a photoconductive substance of an electrophotographic photoreceptor. Furthermore, it was also found that this amino compound can produce a photoreceptor having an unexpected effect by combining with various materials, as will be apparent from the following. The present invention has been completed based on these findings.

SUMMARY OF THE INVENTION It is, therefore, an object of the present invention to solve the various drawbacks of the above-mentioned conventional photoconductors and to provide a photoconductor that can sufficiently satisfy the conditions required in the electrophotographic method. Another object of the present invention is to provide an electrophotographic photosensitive member which is easy to manufacture, relatively inexpensive, and excellent in durability.

That is, the present invention provides an electrophotographic photosensitive member having a photosensitive layer provided on a conductive support, wherein the photosensitive layer contains an amino compound represented by the general formula (I) as an active ingredient. It is a feature.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings. 1 to 3 are cross-sectional views of three typical examples of the photosensitive member according to the present invention, in which the reference numerals 1 and 2 denote conductive supports and 2,2 'and 2 "photosensitive layers. Reference numeral 3 represents a charge generating substance, 4 represents a charge carrier medium or a charge carrier layer, and 5 represents a charge carrier layer.

The amino compound represented by the general formula (I) used in the present invention is described in JP-A-57-73076, JP-A-57-178799,
JP-A-57-205437, JP-A-57-207252, JP-A-58-
It can be obtained by catalytic hydrogenation of the stilbene compounds described in JP-A No. 24696 and JP-A No. 58-69202.

Specific examples of the amino compound represented by the general formula (I) thus obtained are shown below.

The photoconductor of the present invention contains one or more of the above-mentioned amino compounds in the photoconductor 2 (2 ′ or 2 ″). It can be used as shown in FIG. 2 or FIG.

The photosensitive member in FIG. 1 is one in which a photosensitive layer 2 made of an amino compound, a sensitizing dye and a binder (binder resin) is provided on a conductive support 1. The amino compound here acts as a photoconductive substance, and the generation and transfer of charge carriers necessary for light attenuation are performed via the amino compound. However, since the amino compound has almost no absorption in the visible region of light, it is necessary to add a sensitizing dye having absorption in the visible region for sensitization for the purpose of forming an image with visible light. is there.

The photosensitive member shown in FIG. 2 has a photosensitive layer 2'wherein a charge generating layer 3 is dispersed on a conductive support 1 in a charge carrier medium 4 composed of an amino compound and a binder. is there. The amino compound here forms the charge carrier medium together with the binder (or the binder and the plasticizer), while the charge generating substance 3 (charge generating substance such as an inorganic or organic pigment) generates charge carriers. In this case, the charge carrier medium 4 is mainly responsible for receiving the charge carriers generated by the charge generating substance 3 and carrying them. In this photoreceptor, the basic condition is that the charge generation layer and the amino compound do not overlap each other mainly in the visible wavelength range. This is because it is necessary to transmit light to the surface of the charge generating substance 3 in order to efficiently generate charge carriers in the charge generating substance 3. The amino compound represented by the general formula (I) has almost no absorption in the visible region, and when it is combined with the charge generation layer 3 that generally absorbs light in the visible region and generates charge carriers, it is particularly effective as a charge carrier substance. The feature is that it works.

The photosensitive member in FIG. 3 is provided with a photosensitive layer 2 ″, which is formed by stacking a charge generating layer 5 having a charge generating substance 3 as a main component and a charge carrying layer 4 containing an amino compound on a conductive support 1. In this photoreceptor, the light transmitted through the charge transport layer 4 reaches the charge generation layer 5 and the charge carriers are generated in the region, while the charge transport layer 4 receives the injection of the charge carriers. The generation of the charge carriers required for light attenuation is performed by the charge generating substance 3, and the charge carriers are transported by the charge transport layer 4 (mainly the amino compound works). The mechanism is the same as that described for the photoconductor shown in FIG.

In order to actually prepare the photoreceptor of the present invention, if the photoreceptor shown in FIG. 1 is used, one or two or more amino compounds are dissolved in a solution in which a binder is dissolved, and a sensitizing dye is further added thereto. , A liquid to which the photosensitive layer 2 may be formed by coating the liquid on the conductive support 1 and drying the liquid.

The thickness of the photosensitive layer 2 is 3 to 50 μm, preferably 5 to 20 μm
Is appropriate. The amount of amino compounds in the photosensitive layer 2 is 30
˜70 wt%, preferably about 50 wt%, and the amount of the sensitizing dye in the photosensitive layer 2 is 0.1 to 5 wt%, preferably 0.5 to 3 wt%. Sensitizing infections include Brilliant Green, Victoria Blue B, Methyl Violet, Crystal Violet, Acid Violet 6B
Triarylmethane dyes such as rhodamine B, rhodamine 6G, rhodamine G extra, eosin S, erythrosine, rose bengal, xanthene dyes such as fluorescein, thiazine dyes such as methylene blue,
Cyanine dyes such as cyanine, 2,6-diphenyl-4
-(N, N-Dimethylaminophenyl) thiapyrylium perchlorate, benzopyrylium salt (Japanese Patent Publication No.
Pyrylium dyes, etc.) and the like. In addition, these sensitizing charges may be used alone or in combination of two or more kinds.

In addition, in order to produce the photoreceptor shown in FIG. 2, fine particles of the charge generating substance 3 are dispersed in a solution in which one or more amino compounds and a binder are dissolved, and this is used as a conductive support. 1 and dried to form a photosensitive layer 2 '.

The thickness of the photosensitive layer 2'is 3 to 50 .mu.m, preferably 5 to 20 .mu.m.
m is suitable. The amount of the amino compound in the photosensitive layer 2'is 10 to 95 parts by weight, and the amount of the charge generating substance 3 in the photosensitive layer 2'is 0.1 to 50% by weight, preferably 1 to 20% by weight. As the charge generating substance 3, for example, selenium,
Examples of inorganic pigments such as selenium-tellurium, cadmium sulfide, and cadmium sulfide-selenium α-silicon, and organic pigments include CI Pigment Blue 25 (Color Index
CI21180), CI Pigment Red 41 (Color Index CI21200), CI Acid Red 52 (CI451
00), CI Basic Red 3 (CI45210), azo pigment having carbazole skeleton (described in JP-A-53-95033), azo pigment having distyrylbenzene skeleton (described in JP-A-53-133445). , An azo pigment having a triphenylamine skeleton (described in JP-A-53-132347), an azo pigment having a dibenzothiophene skeleton (described in JP-A-54-21728), an azo pigment having an oxadiazole skeleton (Described in JP-A-54-12742), azo pigment having a fluorenone skeleton (described in JP-A-54-22834), azo pigment having a bisstilbene skeleton (described in JP-A-54-17733). ), Azo pigments having a distyryloxadiazole skeleton (described in JP-A-54-2129), azo pigments having a distyrylcarbazole skeleton (described in JP-A-54-14967), and the like. For example, phthalocyanine pigments such as CI Pigment Blue 16 (CI74100), indigo pigments such as CI Eye Bat Brown 5 (CI73410) and CI Eye Bat Die (CI73030), Argos Scarlet B (manufactured by Bayer), Indence Scarlet R (Made by Bayer) and the like. These charge-generating substances may be used alone or in combination of two or more.

Further, in order to prepare the photoreceptor shown in FIG. 3, the charge generating substance is vacuum-deposited on the conductive support 1, or the fine particles 3 of the charge generating substance are dissolved in a binder, if necessary, in a suitable solvent. The dispersion liquid dispersed therein is applied and dried, and if necessary, surface finishing, film thickness adjustment and the like are performed by a method such as buffing to form the charge generation layer 5, on which one or more types are formed. The charge transport layer 4 may be formed by applying a solution in which two or more kinds of amino compounds and a binder are dissolved and drying the solution. The charge generating material used for forming the charge generating layer 5 is the same as that described in the above description of the photosensitive layer 2 '.

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

In any of these photoconductor manufacturing processes, as the conductive support 1, a metal plate or metal foil such as aluminum, a plastic film deposited with a metal such as aluminum, or a paper subjected to a conductive treatment is used. Further, as the binder, condensation resins such as polyamide, polyurethane, polyester, epoxy resin, polyketone, and polycarbonate, and vinyl polymers such as polyvinyl ketone, polystyrene, poly-N-vinylcarbazole, and polyacrylamide are used. All insulating and adhesive resins can be used. If necessary, a plasticizer is added to the binder, and examples of such a plasticizer include halogenated paraffin, polychlorinated biphenyl, dimethylnaphthalene, dibutyl phthalate and the like.

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

To perform copying using the photoreceptor of the present invention, the photosensitive surface is charged and exposed, and then developed, and if necessary,
Transfer to paper etc. The photoreceptor of the present invention has high sensitivity,
In addition, it has excellent advantages such as high flexibility.

Examples will be described below. In the following examples, all parts are parts by weight.

Production Example 10.42 g of 4-N, N-diphenylaminostilbene was dissolved in 100 ml of dioxane, and 5% palladium-carbon 1.0% was added thereto.
4 g was added, and hydrogenation was carried out at 25 ° C. under a hydrogen pressure of 1 atm with a shaking hydrogenation apparatus. After completion of hydrogenation, the reaction mixture was filtered with Celite and evaporated under reduced pressure of dioxane to obtain a colorless oily substance. This was subjected to column chromatography with silica gel-toluene to obtain 9.03 g (yield 86%) of 4-phenethyltriphenylamine (Compound No. 6) as a colorless viscous liquid.

Elemental analysis value (%) C H N measured value 89.27 6.61 4.02 C ₂₆ H ₂₃ N calculated value of 89.34 6.65 4.01 calculated value Infrared absorption spectrum (KBr tablet method) 951 cm ^-1 trans olefin C-H out-of-plane bending angle Dissipation of absorption due to vibration was observed.

Example 1 76 parts of Diane Blue (CI Pigment Blue 25, CI21180) as a charge generating substance, 1260 parts of a 2% tetrahydrofuran solution of a polyester resin (Vylon 200, manufactured by Toyobo Co., Ltd.) and 3700 parts of tetrahydrofuran were ground and mixed in a ball mill. Then, the obtained dispersion liquid was applied onto the aluminum surface of a conductive support made of aluminum-deposited polyester base using a doctor blade, and naturally dried to form a charge generation layer having a thickness of about 1 μm.

On the other hand, 2 parts of No.7 amino compound as a charge carrier substance,
After mixing and dissolving 2 parts of a polycarbonate resin (Panlite K1300, manufactured by Teijin Limited) and 16 parts of tetrahydrofuran to form a solution, this solution was applied onto the charge generation layer using a doctor blade, and then at 80 ° C. for 2 minutes. And then 5 at 105 ℃
Photoreceptor No. 1 was prepared by drying for a minute to form a charge transport layer having a thickness of about 20 μm.

Examples 2 to 27 Photoconductors Nos. 2 to 27 were produced in exactly the same manner as in Example 1 except that the charge generating substance and the charge transporting substance (amino compound) were changed to those shown in Table 1.

Example 28 Selenium was vacuum-deposited to a thickness of about 1 μm on an aluminum plate having a thickness of about 300 μm to form a charge generation layer. Next, 2 parts of the No. 7 amino compound, 3 parts of a polyester resin (Polyester Adhesive 49000 manufactured by DuPont) and 45 parts of tetrahydrofuran were mixed and dissolved to prepare a charge transport layer forming liquid, which was used as the charge generation layer ( A selenium vapor-deposited layer) was coated with a doctor blade, dried naturally, and then dried under reduced pressure to form a charge carrying layer having a thickness of about 10 μm to obtain a photoconductor No. 28 of the present invention.

Example 29 Perylene pigment instead of selenium To form a charge generation layer (thickness is about 0.3 μm) and an amino compound of No. 6 was used instead of No. 7 in the same manner as in Example 28. No.29 was created.

Example 30 A mixture of 1 part of Diane Blue (the same as that used in Example 1) and 158 parts of tetrahydrofuran was pulverized and mixed in a ball mill, and then the amino compound 12 of No. 7 was added thereto.
Parts, 18 parts of polyester resin (Polyester Adhesive 49000 manufactured by DuPont), and further mixed to obtain a photosensitive layer forming liquid, which is applied onto an aluminum vapor-deposited polyester film using a doctor blade, and at 30 ° C. at 30 ° C. After being dried for a minute, a photosensitive layer having a thickness of about 16 μm was formed to prepare a photoconductor No. 30 of the present invention.

Electrostatic copying paper tester (KK Kawaguchi Denki Seisakusho's SP428 type) on the photoconductor Nos. 1 to 30 manufactured in this way
After charging −6KV or + 6KV corona discharge for 20 seconds to charge it, leave it in the dark for 20 seconds, measure the surface potential Vpo (volt) at that time, and then measure the tungsten lamp light on the photoreceptor surface. Irradiation was performed so that the illuminance was 20 lux, and the time (seconds) until the surface potential became 1/2 of Vpo was calculated, and the exposure amount E1 / 2 (look sys. Second) was calculated. The results are shown in Table-2.

Also, after charging each of the above photoconductors using a commercially available electrophotographic copying machine, light irradiation was performed through the original drawing to form an electrostatic latent image, and the latent image was developed using a dry developer, and thus obtained. When the image (toner image) was electrostatically transferred and fixed on plain paper, a clear transferred image was obtained. Even when a wet type developer was used as the developer, a clear transfer image was similarly obtained.

Effects As can be seen from the above examples, the photoconductor of the present invention is excellent not only in the photosensitivity but also in the strength against heat and mechanical shock, and can be manufactured at low cost.

[Brief description of drawings]

1, 2 and 3 are sectional views of the electrophotographic photosensitive member according to the present invention enlarged in the thickness direction. DESCRIPTION OF SYMBOLS 1 ... Conductive support 2, 2 ', 2 "... Photosensitive layer 3 ... Charge generating substance 4 ... Charge carrying medium or charge carrying layer 5 ... Charge generating layer

Claims (1)

[Claims] 1. An amino compound represented by the following general formula (I) on a conductive support. (Wherein R ¹ represents a hydrogen atom, an alkyl group, an alkoxy group, an aryloxy group or a halogen atom, R ^{2 a} hydrogen atom, an alkyl group containing a substituted alkyl group or a substituted or unsubstituted phenyl group, R ³ and R ⁴ Represents an alkyl group, an aralkyl group or an aryl group, and Ar represents an aromatic hydrocarbon.) An electrophotographic photoconductor having a photosensitive layer containing at least one of the above as an active ingredient.