JPS61188543A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic sensitive body high in sensitivity to semiconductor laser beams by incorporating a combination of at least one of 2 kinds of specified positive hole transfer material and at least one of a group of a specified electron transfer materials in a photosensitive layer formed by dispersing an X-type metal phthalocyanine compd. into a binder resin. CONSTITUTION:The electrophotographic sensitive body is obtained by forming on a conductive substrate A the photosensitive layer B prepared by dispersing into the binder 4 made of a generally used synthetic resin, the X-type metal phthalocyanine 1, the electron transfer material, such as a disazo pigment or a cyanine dye deriv. 3, and the positive hole transfer material 2 represented by formula I, A1 being optionally substd. aromatic hydrocarbon or such a hetero ring, and R1, R2, R3 being each H, halogen, optionally substd. alkyl, aralkyl, or aryl, independent of each other, or the positive hole transfer layer B-1 contg. the materials 2, 4, and a charge generating layer B-2 contg. the materials 1, 3 may be formed to prepare a laminate type photosensitive layerphotosensitive layer B.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrophotographic photoreceptor, and more particularly to an electrophotographic photoreceptor suitably used in a radar beam printer using a semiconductor radar.

[Conventional technology]

In 1968, it was discovered that phthalocyanine compounds exhibited photoconductivity.
Since its discovery in 1999, a great deal of research has been conducted on it as a photoelectric conversion material. In recent years, with the development of non-input printing/printing technology, there has been active research and development into radar beam printers that use semiconductor radar for writing. In a radar beam printer used in electrophotography, a uniformly corona-charged photoreceptor is first irradiated with a radar beam modulated based on an input signal to form an image using toner particles. It is believed that this type of radar recording method will improve the image quality, and that it will have the advantage of simplifying, downsizing, and lowering the cost of the device, especially by using semiconductor radar. It will be done.

At present, most of the oscillation wavelengths of semiconductor radars that operate stably are in the near-infrared region (λ) of 780 nm). That is, the recording photoreceptor used therein has a wavelength of 780 nm to 850 nm.
It is necessary to have high sensitivity in the wavelength range. In this case, the half-decrease exposure amount E- of monochromatic infrared light irradiation required for practical sensitivity is 1 μJ/cm or less. Among the photoconductive materials that exhibit high sensitivity in such a long wavelength range, 7-talocyanine compounds are attracting particular attention.

Conventionally, electrophotographic photoreceptors are made of selenium and tellurium.

Inorganic compounds such as cadmium sulfide and zinc oxide, or organic compounds such as 4S-N-vinylcarbazole and bisazo pigments are used. But these are 780
However, in recent years, photoreceptors using an alloy of selenium, tellurium, and arsenic or photoreceptors using dye-sensitized cadmium sulfide have been developed to have sufficient photosensitivity in the long wavelength range of 800 nm to 900 nm. Although it has been reported that they have high sensitivity in the long wavelength region, they are all highly toxic and their environmental safety is being reconsidered as a social issue. In addition, it is thought that it is possible to extend the photosensitive region of photoreceptors using amorphous silicon to a long wavelength region by using a specific doping method and manufacturing method, but at present, the film formation speed is slow and there are problems with mass production, and the price is low. It is difficult to say that it is a photoreceptor.

Among the phthalocyanine compounds that have been studied so far, X-type metal-free phthalocyanine compounds can be cited as compounds that are sensitive in the long wavelength region of 78.0 nm or more.

However, the pigment-resin dispersion photoreceptor using the xM1 metal-free 7-talocyanine compound has relatively high sensitivity near 780 nm, but the sensitivity rapidly decreases in the long wavelength range of 800 nm or more, making it insufficient for practical use. It is.

On the other hand, a pigment-resin dispersion type photoreceptor is characterized by a phenomenon in which the photoresponse is delayed at the initial stage of light irradiation, which is called the Induet 1on effect, and therefore sensitivity tends to decrease significantly for light with weakly absorbed wavelengths.

[Problem that the invention seeks to solve]

An object of the present invention is to provide an electrophotographic photoreceptor that exhibits relatively high sensitivity within the line length range of 780 to 900 nmf.

Another aspect of the present invention. The purpose is to solve the problems of large dark decay and residual potential that occur when producing an electrophotographic photoreceptor by dispersing a phthalocyanine pigment in a charge transporting medium such as polyN-vinylcarazole. The purpose is to provide a photoreceptor. .

[Means for solving the problems] The present invention provides x
An electrophotographic photoreceptor having a photosensitive layer comprising a Wi metal-free 7-talocyanine compound dispersed in a binder, characterized in that the photosensitive layer contains a hole transporting substance and an electron transporting substance. The above object has been achieved with an electrophotographic photoreceptor.

Examples of the resin used as a binder in the present invention include resins generally used as binders for electrophotographic photoreceptors. Suitable examples are listed in Table 1.

Table 1 (Part 1) Table 1 (Part 2) Table 1 (Part 3) Table 1 (Part 4) Table 1 (Part 5) Table 1 (Part 6) 7Table 1 (Part 7) Table 1 (Part 8) Hole transporting substances that can be used in the present invention include, for example, quinoline compounds and derivatives thereof as shown in the general formula (1), and indoline compounds and derivatives as shown in the general formula (10). The variant is preferred. Examples of the variant are listed in Table 2.

Examples of the electron transport substance used in the present invention include disazo pigments, yrylene pigments, anzatron pigments, thiapyrylium salt derivatives, pyrylium salt derivatives, cyanine dye derivatives, and the like. Specific examples are shown in Table 3.

In addition to the X-type metal-free phthalocyanine, the hole-transporting substance, and the electron-transporting substance, an electron-accepting substance may be added to the binder of the photoreceptor of the present invention for the purpose of further increasing the sensitizing effect. Examples of such electron-accepting substances include, for example, benzoic acid, 3,5-dinitrobenzoic acid, halonaphthoquinone, picric acid, picramic acid, chloranylbenzoic acid, chloranylbenzoic acid, m-nitrobenzoic acid,
Examples include 2,6-cyclobenzoquinone and 2,4.5-trinitrofluorenone.

The electrophotographic photoreceptor of the present invention can be prepared by adding, for example, a resin solution in which a type X-type metal-free phthalocyanine, a hole transporting substance, an electron transporting substance, etc., as described above, are dissolved in an organic solvent and using a conventional dispersion machine. It can be produced by uniformly dispersing it using a f-lumineering, paint shaker, red devil, ultrasonic dispersion machine, etc., applying it onto a substrate, and drying it.

Application is usually done using a roll coater or wire)'? -1)
”) Use a lid blade, etc.

The electrophotographic photoreceptor of the present invention can have various structures. Examples are shown in FIGS. 1 to 6.

Figure 1 shows a method in which -X type metal-free phthalocyanine (1), a hole transport material (2) and an electron transport material (3) are dispersed in a binder (4) on a conductive substrate (transfer). Photosensitive layer (B) consisting of
It has been established.

Figure 2 shows one layer of gold-free maple phthalocyanine (1), a hole transport material (2), and an electron transport material (3) on a conductive substrate (4).
and a photosensitive layer (B) comprising an electron-accepting substance (5) dispersed in a binder (4).

The photoreceptors in FIGS. 3 and 4 are made of X-type metal-free phthalocyanine (1), an electron transport material (3), an electron acceptor material (5), and a binder (4) on a conductive substrate (4). A charge generating layer (B-1) consisting of a charge generating layer (B-1) and a photosensitive layer (B) consisting of a charge transporting layer (B-2) consisting of a hole transporting substance (2) and a binder (4) are provided. .

The photoreceptor shown in FIGS. 5 and 6 consists of a conductive substrate (4), a phthalocyanine (1), a hole transport material (2), an electron transport material (3), and an electron acceptor material (5). ) and binder (
4) a charge generation layer (B-1) consisting of a hole transport material (B-1);
2) and a charge transport layer (B-2) comprising a binder (4).

In the case of the photoreceptor shown in FIGS. 1 and 2, the thickness of the photosensitive layer is preferably 3 to 50 μm, more preferably 5 to 20 μm. In the case of the photoreceptor shown in FIGS. 3 to 6, the thickness of the charge generation layer is preferably 5A or less, more preferably 0.01μ.
The thickness of the charge transport layer is preferably 3 to 2μ.
It is 50μ, more preferably 5 to □20μ.

The proportion of anti-type metal-free phthalocyanine in the photosensitive layer of the electrophotographic photoreceptor of the present invention is 0.05 to 90% by weight, preferably 15 to 50% by weight, based on the photosensitive layer, and hole transport The ratio of substances is 0.0 to type X metal-free phthalocyanine
0.1 to 90% by weight, preferably 15 to 50% by weight, and the proportion of the electron-transporting substance to the X-type metal-free phthalocyanine is 0.1 to 90% by weight, preferably 10 to
The proportion of the electron-accepting substance is 30% by weight, and the proportion of the electron-accepting substance is 0,00 to 90% by weight, preferably 0.1 to 10% by weight, based on the X-type metal-free phthalocyanine. Note that a plasticizer can be used together with a binder in producing any of the photoreceptors shown in FIGS. 1 to 6.

As the conductive support of the photoreceptor of the present invention, for example, a metal plate or metal foil made of aluminum or the like, a glass film deposited with a metal such as aluminum, or paper subjected to conductive treatment is used.

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 for these layers include polyamide,
The film may be made of nitrocellulose, casein, polyvinyl alcohol, etc., and preferably has a film thickness of 1 μm or less.

Hereinafter, the present invention will be specifically explained using examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof.

The disazo pigments in the examples show the electron transport substances listed in Table 3 of the specification, and the hole transport substance A also shows the properties of the electron transport substances listed in Table 2 of the specification.
.

〔Example〕

After completely dissolving Example 1, it was coated and dried on an aluminum vapor-deposited Mylar film to form a charge transport layer of 10 types. Next, the mixture was uniformly dispersed for 185 hours using a paint shaker, and then dried on a KjII cloth so that the photoreceptor had a film thickness of about 15-15-10cm on the charge transport layer, and the product FfIIj!
A photoreceptor was prepared.

"E/4'-Analyzer 5p-428J (manufactured by Kawaguchi Electric Seisakusho Co., Ltd.)" was used to measure the electrophotographic characteristics of the photoreceptor.

(+) Surface potential V of the photoreceptor immediately after applying each voltage of 6 kV and (→6 kV to the surface of the photoreceptor. (V
).

Surface potential V of the photoreceptor 10 seconds after stopping voltage application,
. (to), and measure the charge retention capacity of the photoreceptor as v, O/v.

It was evaluated based on the value of

When the surface of the charged photoreceptor was exposed to light using a tungsten lung as a white light source, the sensitivity of the photoreceptor was measured.

When the exposure intensity is 5 Aug, the exposure amount required for the surface potential after exposure to decrease to the ring of the initial surface potential ~(j(1!)
sl@(+) and the surface potential after exposure is 1 of the initial surface potential.
Exposure amount required to reduce by 15K E (tux, 5e
e) and the surface potential vIs(
) was measured, and the sensitivity of the photoreceptor was evaluated based on these physical quantities.

The mixture of Comparative Example 1 was uniformly dispersed in the same manner as in Example 1, and then dispersed onto an aluminum vapor-deposited Mylar film provided with casein so that the film thickness was 15 mm.
It was dried and an electrophotographic photoreceptor was prepared.

Comparative Example 2 A photoreceptor having the same composition and structure as Example 1 was prepared except that disazo pigment P-13 was not added.

FIG. 7 shows the spectral sensitivities of the photoreceptors of Example 1 and Comparative Example 1. FIG. 8 shows optical attenuation characteristic curves of the photoreceptors of Example 1, Comparative Example 1, and Ratio Example 2.

From FIG. 7, it can be seen that the photoreceptor of Example 1 shows no decrease in sensitivity in the long wavelength region of 80011 m or more.

It can be seen from FIG. 8 that the residual potential is significantly reduced by adding the disazo pigment.

! J Example 2 After uniformly dispersing the 0 mixture using the same method as in Example 1 above, it was coated on an aluminum vapor-deposited Mylar film coated with casein to a thickness of 3 μm, and dried to generate a charge. Created a layer. This 1 busy hole transport agent Al1-13
5.0.9. rU, N Rimmer” (manufactured by Unitika @) Co., Ltd.)
, oII and Geochusan 45.0# solution to a film thickness of 1
It was coated and dried to a thickness of 2 μm to form a charge transport layer, and a laminated photoreceptor was prepared.

The mixture of Example 3 was uniformly dispersed in the same manner as in Example 1, and then coated on an aluminum vapor-deposited Mylar film coated with casein to a thickness of 0.5 μm and dried to generate a charge. layered. On top of this, a hole transport material Al-13s,
oy, rtys rimmer” (manufactured by Unitika Co., Ltd.) s, o
A solution of y and dioxane 45.0& was applied and dried to a film thickness of 12 μm to form a charge transport layer, and a laminated photoreceptor was prepared.

The mixture of Comparative Example 3 was uniformly dispersed in the same manner as in Example 1, and then coated on an aluminum vapor-deposited Mylar film coated with casein to a thickness of 0.5 μm and dried to generate a charge. layered. A charge transport layer similar to that in Example 3 was provided thereon to produce a laminated photoreceptor.

The electrophotographic characteristics of the photoreceptors of Examples 2 and 3 and Comparative Example 3 are summarized in Table 4K.

Table 4 Further, the spectral sensitivities of the photoreceptors of Examples 2 and 3 and Comparative Example 3 are shown in FIG.

Examples 4 to 11 In the photoreceptor of Example 1, various combinations of hole transport materials and electron transport materials were used to create various photoreceptors.The characteristics of each are summarized in Table 5.

〔Effect of the invention〕

The electrophotographic photoreceptor of the present invention contains a hole transporting substance and an electron transporting substance in the photosensitive layer of the electrophotographic photoreceptor, which has a photosensitive layer formed by dispersing a chi-free metal phthalocyanine compound in a binder. In particular, it has sufficient sensitivity in the long wavelength region of 780 to 900 am, and in addition, the residual potential is small. 750 ~ 750~ of semiconductor lasers, etc.
900 am light source t-1! ! It can also be applied to the other optical recording devices used.

[Brief explanation of drawings]

1 to 6 are enlarged partial cross-sectional views of an electrophotographic photoreceptor according to the present invention. (1) ... Ri-type gold-free maple phthalocyanine (2) ... Hole transport material (3) ... Electron transport material (4) ... Binder (5) ... Charge-accepting material (6) Conductive support (B) Photosensitive layer (B-1) Charge transport layer (B-2) Charge generation layer Figure 7 shows the photoreceptor of Example 1 and 3 is a diagram showing the relative spectral sensitivity of each photoreceptor of Comparative Example 1. FIG. FIG. 8 shows the photoconductor of Example 1, the photoconductor of Comparative Example 1, and Comparative Example 2.
9 is a diagram showing the light attenuation characteristic curves of the photoreceptors of Example 2, Example 3, and Comparative Example 2.
FIG. 3 is a diagram showing the relative spectral sensitivities of the respective photoreceptors. Agent Patent Attorney Masaru Takahashi Toshiyukicho (nm)

Claims (1)

[Claims] 1. An electrophotographic photoreceptor having a photosensitive layer formed by dispersing an x-type metal-free phthalocyanine compound in a binder, the photosensitive layer containing a hole transporting substance and an electron transporting substance. An electrophotographic photoreceptor characterized by: 2. The hole transport substance has a general formula ▲ Numerical formula, chemical formula, table, etc. ▼... (I) (In the formula, A_1 is an aromatic hydrocarbon group or an aromatic heterocyclic group that may have a substituent. , R_1, R_2 and R
Each of _3 independently represents a hydrogen atom, a halogen atom, or an alkyl group, an aralkyl group, or an aryl group which may have a substituent. ) The electrophotographic photoreceptor according to claim 1. 3. The hole transport substance has a general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼... (II) (In the formula, A_2 is an aromatic hydrocarbon group or an aromatic heterocyclic group that may have a substituent. and R_4 and R_5 each independently represent a hydrogen atom, a halogen atom, or an alkyl group, an aralkyl group, or an aryl group that may have a substituent. Photoreceptor. 4. Claim 1, wherein the electron transport substance is one or more compounds selected from the group consisting of disazo pigments, perylene pigments, anzanthrone pigments, thiapyrylium salt derivatives, pyrylium salt derivatives, and cyanine dye derivatives. The electrophotographic photoreceptor according to items 1 and 2.