JPH0829995A - Photoreceptor for electrophotography - Google Patents

Abstract

PURPOSE:To provide a photoreceptor, which has high spectral sensitivity over from the area of visible light to the area of near infrared ray and which is provided with a printer function using a semiconductor laser as a light source and a copying function using the white light as a light source. CONSTITUTION:A photosensitive layer of a photoreceptor for electrophotography contains oxytitaniumphthalocyanine and the disazo compound expressed with the chemical formula. In this chemical formula, K1, K2 mean the coupler residual group, which respectively include hydroxyl group, and the K1, K2 can be the same one or they can be different from each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photoconductor for electrophotography, which has a wide spectral sensitivity from visible light to near infrared region, high sensitivity and low residual potential. Is.

[0002]

2. Description of the Related Art As a photoconductor for electrophotography, a photoconductor using an inorganic photoconductive substance such as selenium, cadmium sulfide, or zinc oxide has been used, but recently, it is produced without pollution. An organic photoconductive substance (OPC) having many advantages such as easy handling, good image quality, and easy production of photoconductors of various shapes such as drums, sheets and belts. The so-called OPC photoconductor that uses
Moreover, the ratio is increasing year by year.

Polyvinylcarbazole (PVK) and an electron-withdrawing compound 2,4,7-trinitrofluorenone (TN) were first put into practical use as an OPC photoreceptor.
It utilized the sensitizing effect of the charge transfer complex formed by mixing with F). However, since then, many charge transfer complex type OPC photoconductors have been developed.
Those having a performance superior to that of the PVK-TNF type photoreceptor have not been put into practical use. Presently mainly used is a photoreceptor called a function-separated type, in which the functions of generating and moving charge carriers are separated and shared by different compounds. In the function-separated type photoreceptor, it is possible to combine a compound with high charge carrier generation efficiency and a compound with high transfer efficiency, and there is a wide selection of materials with excellent durability, high sensitivity and durability. It is a type that makes it possible to obtain a photoreceptor having excellent properties.

Such an electrophotographic photosensitive member is generally used in a copying machine,
Widely used in printers and the like. For example, in a copying machine, a photoconductor having a photosensitivity to a visible light source has been developed, while a printer having a semiconductor laser as a light source is used at the end of a computer. The electrophotographic photosensitive member incorporated in the printer must have high sensitivity in the near infrared region. Further, a printer using a semiconductor laser is being developed to have a copying function using white light as a light source. In this case, the photosensitive member must first have high sensitivity in the near infrared region to adapt to the printer function, and also have high sensitivity in the visible light region to adapt to the copying function. That is, there is a demand for the development of a function-combined electrophotographic photosensitive member which can be applied to an apparatus having both the printer function and the copying function using white light as the light source as described above.

Currently, as carrier-forming materials for copying machines, for example, JP-A-55-22834 and JP-A-56-11.
Many bisazo pigments have been studied and put into practical use as already known from No. 6040. Photoreceptors containing such bisazo pigments have relatively good sensitivity in the short to medium wavelength range, but have low sensitivity in the long wavelength range and should be used in printers that use a semiconductor laser beam as the light source. I couldn't.

On the other hand, gallium / aluminum / arsenic (Ga-Al), which is widely used as a light source for printers at present,
The oscillation wavelength of the -As) type light emitting device is 750 nm or more. Methine squalic acid-based dyes, cyanine-based dyes, pyrylium-based dyes, thiapyrylium-based dyes, polyazo-based dyes, phthalocyanine-based dyes, and the like are known as carrier-generating materials having sensitivity in such a long wavelength region.
Among these, methacrylic acid squalane, cyanine dyes, pyrylium dyes, and thiapyrylium dyes are relatively easy to increase the spectral sensitivity to a long wavelength, but lack the practical stability of repeated use. The system pigment is
It is difficult to increase the wavelength of absorption, and there are difficulties in manufacturing.
Phthalocyanine dyes are relatively easy to synthesize and
Since many of them have an absorption peak in a wavelength range of 0 nm or more and have an absorption wavelength extending to a relatively long wavelength range as compared with other dyes, they are expected as a charge generating agent for a long wavelength light source and have been widely studied. However, such an electrophotographic photosensitive member having a sensitivity in a long wavelength region does not have sufficient photosensitivity in a medium wavelength region to a short wavelength region and cannot be adapted to a copying function using a white light source or the like.

[0007]

As described above, the electrophotographic photosensitive member for visible light and the electrophotographic photosensitive member for semiconductor laser each have relatively good characteristics by themselves, but in the short wavelength region. There is a demand for a photoreceptor having a wide sensitivity over a long wavelength range. Furthermore, with the speeding up of electrophotographic copiers and printers and the reduction in diameter of photosensitive drums, the time required for the copying process is significantly shortened, and
If digitization progresses and the number of times of copying increases, it will be necessary to meet various requirements such as high sensitivity to photoconductors, stabilization of charging characteristics, high response of light attenuation, and physical and chemical durability. I won't.

An example of such a panchromatic photosensitive member whose sensitivity can be adjusted is, for example, Japanese Patent Laid-Open No. 63-2.
In JP-A-36048, a photoreceptor containing both N-methyldiphenylamine-type and anthraquinone-type bisazo pigments, and in JP-A-63-236049, a phenanthraquinone-type is used instead of the anthraquinone-type in the photoreceptor. Although photoconductors containing the bisazo pigment have been proposed, these photoconductors have insufficient photosensitivity in the long wavelength region and are not actually satisfactory. Further, JP-A-3-37667 discloses a photoconductor containing both titanyl phthalocyanine and a bisazo pigment having a specific structure, but this photoconductor is panchromatic but has an overall sensitivity. Was insufficient and did not satisfy the above-mentioned requirements for high sensitivity and high responsiveness.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to have a high spectral sensitivity from visible light to the near infrared region and to have both a printer function using a semiconductor laser as a light source and a copying function using a white light as a light source. It is to provide a high-performance electrophotographic photoconductor that can be applied to a device having both of the above.

[0010]

SUMMARY OF THE INVENTION The above objects of the present invention are as follows.
This is achieved by incorporating oxytitanium phthalocyanine and the disazo compound represented by the general formula [I] into the photosensitive layer for electrophotography.

[0011]

Embedded image

(In the formula, K ₁ and K ₂ each represent a coupler residue containing a hydroxyl group, and K ₁ and K ₂ may be the same or different.) The present invention will be described in detail below. The oxytitanium phthalocyanine used in the present invention includes, for example, the following general formula [II]

[0013]

Embedded image

(In the formula, X represents a halogen atom, and n is 0.
Represents a number from 1 to 1. ). In the general formula [II], X is a chlorine atom and n is 0.
It is preferably from 0.5 to 0.5. The oxytitanium phthalocyanine used in the present invention can be obtained by a known method such as 1,2-dicyanobenzene (orthophthalodinitrile).
It can be easily synthesized from the titanium compound.

Then, the obtained oxytitanium phthalocyanine is subjected to the hot water treatment disclosed in JP-A-62-67094 or the mechanical grinding treatment disclosed in JP-A-2-215866 to obtain the desired crystal. You can get the mold. Further, the crystalline oxytitanium phthalocyanine used in the present invention is not limited only to the crystalline oxytitanium phthalocyanine produced by the above production method, for example, other crystalline oxytitanium phthalocyanine is also suitable. It may be oxytitanium phthalocyanine which can be produced by treatment and produced by any production method. The Cu-Kα
In the X-ray diffraction spectrum by the X-ray, the Bragg angle (2
(θ ± 0.2 °) shows a clear diffraction peak at 27.3 ° and belongs to the crystal form which is crystallographically the same as the crystal form shown in the X-ray diffraction spectrum in FIG. Three
Other than °, it is preferable to show relatively clear diffraction peaks near 9.5 ° and 24.1 °. Further, as oxytitanium phthalocyanine, other crystal type, for example, amorphous oxytitanium phthalocyanine black angle (2θ ± 0.2 °) 9.3 °, 10.6
°, 13.2 °, 15.1 °. 15.7 °, 16.1
°, 20.8 °, 23.3 °, 26.3 °, 27.1 °
Crystalline oxytitanium phthalocyanine having a strong diffraction peak in the background. Among these, the intensity of the diffraction peak at the black angle of 26.3 ° is the strongest, and the intensity of the diffraction peak at the black angle of 4 to 8 ° is 5% or less with respect to the intensity of the diffraction peak at the black angle of 26.3 °. It is preferably strong. Black angle (2θ ± 0.2 °) 7.0 °, 15.6
Examples include crystalline oxytitanium phthalocyanine having strong diffraction peaks at °, 23.4 °, and 25.5 °. Hereinafter, oxytitanium phthalocyanine is referred to as "phthalocyanine".

In the disazo pigment represented by the general formula [I] according to the present invention, K ₁ and K ₂ are preferably

[0017]

[Chemical 4] Z ₁ and Z ₂ are represented by the formula [I ′]

[0018]

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(In the formula, A represents a heterocyclic divalent group which may have a substituent containing a nitrogen atom in the ring or a divalent group of an aromatic hydrocarbon which may have a substituent. Represents a divalent group. Examples of the divalent group of an aromatic hydrocarbon include a divalent group of a monocyclic aromatic hydrocarbon such as an o-phenylene group, an o-naphthylene group, a peri-naphthylene group, a 1,2-anthraquinonylene group, Examples thereof include divalent groups of condensed polycyclic aromatic hydrocarbons such as 9,10-phenanthrylene group.

Examples of the heterocyclic divalent group containing a nitrogen atom in the ring include, for example, 3,4-pyrazolediyl group and
5,3-pyridinediyl group, 4,5-pyrimidinediyl group, 6,7-indazolediyl group, 5,6-benzimidazolediyl group, 6,7-quinolinediyl group and the like
Examples thereof include a 10-membered ring nitrogen atom, and preferably a heterocyclic divalent group containing 2 or less nitrogen atoms in the ring. In consideration of sensitivity and durability, o-phenylene group, o-naphthylene group, peri-naphthylene group, 2,3-pyridinediyl group, 4,5-pyrimidinediyl group, especially o-phenylene group, o-naphthylene group Groups are preferred.

In the present invention, the divalent group of these aromatic hydrocarbons and the divalent group of the heterocycle containing a nitrogen atom in the ring may have a substituent. Examples of the substituent include an alkyl group such as a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, and an n-hexyl group; a methoxy group, an ethoxy group, and propoxy group. Group, alkoxy group such as butoxy group; amino group; alkylamino group such as methylamino group, ethylamino group, dialkylamino group such as dimethylamino group, diethylamino group; hydroxy group; nitro group; cyano group; fluorine atom, chlorine Atom, bromine atom, halogen atom such as iodine atom; carboxyl group; alkoxycarbonyl group such as ethoxycarbonyl group; carbamoyl group; aryloxy group such as phenoxy group; arylalkoxy group such as benzyloxy group;
Examples thereof include aryloxycarbonyl groups such as phenyloxycarbonyl group. Among them, alkyl group, alkoxy group, amino group, alkylamino group, dialkylamino group, nitro group, halogen atom, hydroxy group, carboxyl group, especially methyl group, methoxy group, nitro group, chlorine atom, hydroxy group, amino group Or a dimethylamino group is preferred.

The disazo compound of the present invention can be synthesized, for example, by the method described in JP-A-63-61258. That is, a coupling component represented by the following general formula [III-A] and / or [III-B]

[0023]

[Chemical 6]

(Wherein A has the same meaning as in the above general formula [I ']) and the following structural formula [IV]

[0025]

[Chemical 7]

It can be easily synthesized by a known coupling reaction with a tetrazonium salt of diaminodibenzalacetone represented by: General formulas [III-A] and [III-B]
The coupler component represented by the formula (3) is, for example, 3-hydroxynaphthalic anhydride [V] according to the following reaction formula (1).
And aromatic diamine [VI] are heated in a solvent such as acetic acid and dehydrated and condensed. (J. Che
m. Soc. , 1937 , 1764) Reaction formula (1)

[0027]

Embedded image

The coupler component obtained by the above synthesis method is obtained as a mixture of isomers of the general formulas [III-A] and [III-B], but any isomer can be used in the present invention. The aromatic diamine represented by the above formula [VI] is a primary diamine at the o- or peri-position, and examples thereof include o-phenylenediamine, 4-nitro-o-phenylenediamine, 4-methyl-o-phenylene. Diamine, 4-ethyl-o-phenylenediamine,
4-i-propyl-o-phenylenediamine, 4,5-
Dimethyl-o-phenylenediamine, 4-methoxy-o
-Phenylenediamine, 4,5-diethoxy-o-phenylenediamine, 4-nitro-o-phenylenediamine, 3,5-dinitro-o-phenylenediamine, 4-
Chloro-o-phenylenediamine, 4-bromo-o-phenylenediamine, 4-iodo-o-phenylenediamine, 4-chloro-o-phenylenediamine, 4-carboxy-o-phenylenediamine, 4-methoxycarbonyl-o- O-Phenylenediamines such as phenylenediamine; condensation of 1,2-naphthylenediamine, 2,3-naphthylenediamine, 1,8-naphthylenediamine, 1,2-diaminoanthraquinone, 9,10-diaminophenanthrene, etc. Polycyclic aromatic hydrocarbon diamines; 2,
3-diaminopyridine, 3,4-diaminopyridine,
Diamines of heteromonocyclic compounds such as 4,5-diaminopyrimidine and 3,4-diaminopyrazole; 5,6-diaminoindazole, 6,7-diaminoindazole,
Examples thereof include diamines of condensed heterocyclic compounds such as 5,6-diaminobenzimidazole and 5,6-diaminoquinoline, and substituted derivatives thereof.

In the present invention, as another method for obtaining the coupler component, 3-hydroxynaphthalic acid or its ester is used in place of 3-hydroxynaphthalic anhydride [V] in the above reaction formula (1). Examples of the method include a method of reductively condensing using a monoamino-mononitro derivative instead of an aromatic diamine, or a method of condensing with an aromatic diamine using 3-sulfonaphthalic anhydride and then hydrolyzing a sulfo group. To be The azo compound of the present invention is
It is obtained by the above-mentioned method, but when the mixture of the above-mentioned general formula [III-A] and general formula [III-B] is used as a coupler component, the following general formula [IA] and general formula [I]
-B] and the isomer represented by the general formula [IC].

[0030]

[Chemical 9]

[0031]

[Chemical 10]

[0032]

[Chemical 11]

In the present invention, these mixtures can be used as they are. Representative examples of the disazo compound used in the present invention include the disazo compounds shown in Table 1 below.

[0034]

[Table 1]

[0035]

[Table 2]

[0036]

[Table 3]

[0037]

[Table 4]

[0038]

[Table 5]

[0039]

[Table 6]

[0040]

[Table 7]

The disazo compound of the general formula [I] according to the present invention has a high sensitivity in the region of 450 nm to 600 nm, and complements the sensitivity of the phthalocyanine used in the present invention in the low-sensitivity spectral region. It has a wide sensitivity from a short wavelength region to a long wavelength region when used in combination with, and further, the sensitivity can be easily adjusted by changing the mixing ratio of the disazo compound and the phthalocyanine. Such combined use of different kinds of charge generating substances does not necessarily have a uniform selection means, and in the present invention, the combination of the phthalocyanine and the disazo compound is determined from a large number of compounds by experiments. Is.

The photoconductor of the present invention is suitable as a copying machine (for example, an image signal of a fluorescent lamp, a halogen lamp, a cannon lamp, or an analog signal) which requires a main spectral sensitivity in the visible region, and in the visible region. It is also suitable as a printer (for example, a light emitting diode, a gas laser such as a He—Ne laser, an image signal, that is, a digital signal) such as a semiconductor laser, which requires spectral sensitivity on the long wavelength side or in the near infrared region. In this sense, both analog and digital systems can be realized.

Next, as a method for producing a coating liquid for coating the photosensitive layer, the phthalocyanine and the disazo compound are mixed, dispersed in a dispersion medium, and finally exposed in a state of being mixed with a binder resin. It is prepared as a coating solution for coating a layer, or phthalocyanine and disazo compound are respectively dispersed in a dispersion medium, and then mixed with a binder resin to prepare a mixture, and the prepared solutions are mixed to form a photosensitive layer. It is used as a coating liquid for coating a layer.

Various solvents may be used as the dispersion medium. For example, ethers such as diethyl ether, dimethoxymethane, tetrahydrofuran and 1,2-dimethoxyethane; ketones such as acetone and methyl ethyl ketone;
Esters such as methyl acetate and ethyl acetate; methanol,
Alcohols such as ethanol and propanol can be used alone or in admixture of two or more.

As the binder resin, polyvinyl butyral, polyvinyl acetal, polyester, polycarbonate, polystyrene, polyester carbonate,
Vinyl polymers such as polysulfone, polyimide, polymethylmethacrylate and polyvinyl chloride, and their copolymers, phenoxy, epoxy, silicone resins and the like, or partially cross-linked cured products thereof can be used alone or in combination of two or more. As a method of dispersing the phthalocyanine and the bisazo compound, a known method such as a ball mill, a sand grind mill, a planetary mill or a roll mill can be used.

As a method of mixing the binder resin with the phthalocyanine and disazo compound particles, for example, a method of dispersing the binder resin in the form of powder or simultaneously adding a polymer solution of the binder resin during the dispersion treatment of the phthalocyanine and disazo compound particles, a dispersion liquid is used. Any method such as a method of mixing the binder resin in the polymer solution or a method of mixing the polymer solution in the dispersion liquid may be used.

The content ratio of the phthalocyanine and the disazo compound is from 0.05 part by weight to 10 parts by weight of the disazo compound with respect to 1 part by weight of the phthalocyanine. When the phthalocyanine and disazo compound pigments are separately dispersed in a dispersion medium and further adjusted to be mixed with a binder resin, and the adjusted liquids are mixed to prepare a coating liquid for coating the photosensitive layer. The mixing method of the adjusted liquids is to use a mechanical stirrer, a homomixer, a homogenizer, or the like. Alternatively, any known method such as application of ultrasonic waves and mixing may be used.

Next, the dispersion liquid obtained here may be diluted with various solvents in order to obtain liquid properties suitable for coating. As this solvent, for example, the solvents exemplified as the dispersion medium can be used. The ratio of the phthalocyanine or disazo compound to the binder resin is not particularly limited, but generally the total amount of the phthalocyanine and disazo compound is 5 parts by weight per 100 parts by weight of the resin.
It is used in the range of up to 500 parts by weight. Moreover, in this dispersion, the concentration of the phthalocyanine and the disazo compound is preferably used in the range of 0.1% by weight to 10% by weight.

If necessary, a charge transport material can be included. Examples of the charge transport material include 2,4,7-
Electron withdrawing substances such as trinitrofluorenone, tetracyanoxydimethane, carbazole, indole, imidazole, oxazole, oxadiazole, pyrazoline,
Examples thereof include heterocyclic compounds such as thiazole, aniline derivatives, hydrazone compounds, aromatic amine derivatives, stilbene derivatives, and electron-donating substances such as polymers having a group composed of these compounds in the main chain or side chain. The ratio of charge transport material to binder resin is binder resin 1
The charge transport material may be used in the range of 5 to 500 parts by weight based on 00 parts by weight.

Using the dispersion liquid thus prepared,
A charge generation layer is formed on a conductive support, and a charge transport layer is laminated thereon to form a photosensitive layer, or a charge transport layer is formed on a conductive support and the dispersion liquid is formed on the charge transport layer. To form a charge generating layer to form a photosensitive layer, or to form a charge generating layer from a conductive support to form a charge generating layer to form a photosensitive layer, thereby forming a photosensitive layer. be able to. Further, in the present invention, since two kinds of oxytitanium phthalocyanine and disazo compound are used as the charge generating substance, it is possible to take separate charge generating layers. For example, a layer structure in which a first charge generation layer containing a disazo compound, a second charge generation layer containing oxytitanium phthalocyanine are laminated on a conductive support, and a charge transport layer is further laminated thereon, A layer structure in which a charge transport layer is formed on a conductive support, and a first charge generation layer containing oxytitanium phthalocyanine and a second charge generation layer containing a disazo compound are further laminated thereon are preferable. The thickness of the charge generation layer is preferably in the range of 0.1 μm to 10 μm when the photosensitive layer is laminated with the charge transport layer, and the thickness of the charge transport layer is preferably 5 μm to 60 μm. When the photosensitive layer is formed with a single structure of only the charge generation layer, the thickness of the charge generation layer is preferably in the range of 5 μm to 60 μm. In the case of two charge generation layers, the first layer has a thickness of 0.01 to 10 μm,
More preferably, 0.05 to 1 μm, and the second layer is
0.01 to 10 μm, more preferably 0.5 to 5 μm
Is preferred.

When the charge transport layer is provided, as the charge transport substance used therein, the materials exemplified as the charge transport substance can be used. A binder resin is blended with these charge transport substances as needed. As the binder resin, for example, those exemplified as the binder resin can be used. In the photosensitive layer,
If necessary, various additives such as antioxidants and sensitizers may be included.

The photosensitive layer is provided on the conductive support, and examples of the conductive support include aluminum, stainless copper,
An insulating support such as a metal material such as nickel, a polyester film having a conductive layer such as aluminum, copper, palladium, tin oxide or indium oxide provided on the surface thereof, paper or glass is used. A well-known barrier layer which is commonly used may be provided between the conductive support and the photosensitive layer.

Examples of the barrier layer include an aluminum anodic oxide coating, an inorganic layer such as aluminum oxide and aluminum hydroxide, polyvinyl alcohol, casein, polyvinylpyrrolidone, polyacrylic acid, celluloses, gelatin, starch, polyurethane, polyimide, polyamide, Etc. are used. The thickness of the barrier layer is 0.
The range of 1 μm to 20 μm is preferable, and the range of 0.1 μm to 10 μm is most effective.

[0054]

The photoconductor of the present invention has a wide range of visible light to near-infrared light and high spectral sensitivity, and has a printer function using a semiconductor laser as a light source and a copying function using a white light as a light source. It is possible to provide a photoreceptor having excellent durability that can be applied to a device having both functions.

[0055]

EXAMPLES The present invention will be described in more detail with reference to Examples and Production Examples, but the invention is not limited thereto. Example 1 In the X-ray diffraction spectrum shown in FIG. 1, the black angle (2θ ±
0.2 °) 2 parts by weight of oxytitanium phthalocyanine showing a sharp peak at 27.3 °, No. 1 in Table-1. 200 parts by weight of n-propanol was added to 8 parts by weight of the disazo compound of 2, and the mixture was pulverized with a sand grind mill for 10 hours and subjected to atomization dispersion treatment. Next, polyvinyl butyral (produced by Denki Kagaku Kogyo KK, trade name Denka Butyral # 6000)
C) A dispersion was prepared by mixing with 5 parts by weight of a 10% methanol solution. Next, a charge generation layer was provided on the aluminum vapor-deposited surface obtained by vapor-depositing this dispersion on a polyester film by a bar coater so that the film thickness after drying was 0.4 μm. Next, 56 parts by weight of the following hydrazone compound was formed on the charge generation layer.

[0056]

[Chemical 12]

14 parts by weight of the following hydrazone compound,

[0058]

[Chemical 13]

And 1.5 parts by weight of the following cyano compound

[0060]

Embedded image

Also, a solution prepared by dissolving 100 parts by weight of a polycarbonate resin (trade name, Novalex 7030A, manufactured by Mitsubishi Kasei Co., Ltd.) in 1000 parts by weight of 1,4-dioxane was applied by a film applicator, and the film thickness after drying. Was set to 17 μm, the charge transport layer was provided. The photoconductor thus obtained is referred to as photoconductor A.

Example 2 The same as Example 1 except that the mixing ratio of the oxytitanium phthalocyanine and the disazo compound used in Example 1 was changed to 5 parts by weight of oxytitanium phthalocyanine and 5 parts by weight of the bisazo compound. A photoconductor was created.
The photoconductor thus obtained is referred to as photoconductor B.

Example 3 Similar to Example 1, except that the mixing ratio of the oxytitanium phthalocyanine and the disazo compound used in Example 1 was replaced by 8 parts by weight of oxytitanium phthalocyanine and 2 parts by weight of the bisazo compound. A photoconductor was created.
The photoconductor thus obtained is referred to as a photoconductor C.

Example 4 Instead of the disazo compound used in Example 1, Table-
No. 1 Except that 8 parts by weight of the disazo compound of 1 was used,
A photoconductor was prepared in the same manner as in Example 1. The photoconductor thus obtained is referred to as a photoconductor D.

Example 5 Instead of the disazo compound used in Example 1, Table-
No. 1 Except that 8 parts by weight of the disazo compound of 6 was used,
A photoconductor was prepared in the same manner as in Example 1. The photoconductor thus obtained is referred to as a photoconductor E.

Example 6 Instead of the disazo compound used in Example 1, Table-
No. 1 A photoconductor was prepared in the same manner as in Example 1 except that 8 parts by weight of 16 disazo compounds were used. The photoconductor thus obtained is referred to as a photoconductor F.

Example 7 In place of the disazo compound used in Example 1, Table-
No. 1 A photoconductor was prepared in the same manner as in Example 1 except that 8 parts by weight of the disazo compound of 18 was used. The photoconductor thus obtained is referred to as a photoconductor G.

Example 8 Instead of the disazo compound used in Example 1, Table-
No. 1 Except that 8 parts by weight of the disazo compound of 5 was used,
A photoconductor was prepared in the same manner as in Example 1. The photoconductor thus obtained is referred to as a photoconductor H.

Example 9 Instead of the disazo compound used in Example 1, Table-
No. 1 Except that 8 parts by weight of the disazo compound of 6 was used,
A photoconductor was prepared in the same manner as in Example 1. The photoreceptor thus obtained is referred to as a photoreceptor I.

[Evaluation] Obtained photoreceptors A, B, C, D,
E, F, G, H, and I were measured as a half-exposure sensitivity as an initial electrical characteristic by an electrostatic copying paper test apparatus (Kawaguchi Denki Seisakusho, Model EPA-8100). That is, the photoreceptor is negatively charged by corona discharge in the dark, and then 780
nm monochromatic light is continuously exposed, and the surface is from -700v-
The amount of exposure (E1 / 2) required to reduce to 350v and the residual potential (Vr) were measured. The results are shown in Table-2. From Table-2, the photoconductors A, B, C, D, E of the present invention,
It can be seen that F, G, H and I have high sensitivity to 780 nm monochromatic light and have low residual potential. Further, comparing the photoconductors A, B and C of the present invention, it is shown that the sensitivity can be freely controlled over a wide range by changing the mixing ratio of the phthalocyanine compound and the bisazo compound.

[0071]

[Table 8]

Further, the photoconductors A and F were mounted on a photoconductor spectral sensitivity measuring device, and the spectral sensitivity was measured. That is,
The amount of exposure required to reduce the surface from -700v to -350v (E1 / 2) by negatively charging the photoreceptor by corona discharge in the dark and then continuously exposing it to monochromatic light separated by a monochromator. Was measured. The results are shown in FIG. 2, where the reciprocal of the measured exposure dose is the sensitivity. From FIG. 2, it is found that the photoconductor A of Example 1 in which the disazo compound according to the present invention and the phthalocyanine compound are used in combination has a wide and high sensitivity spectrum from the visible light region to the near infrared light region. .

[Brief description of drawings]

FIG. 1 is an X-ray diffraction spectrum diagram of oxytitanium phthalocyanine used in Example 1.

FIG. 2 is a spectral sensitivity spectrum diagram of the photoconductor A of Example 1.

Claims (2)

[Claims] 1. An electrophotographic photosensitive member comprising a conductive support and a photosensitive layer containing at least a charge generating substance and a charge transporting substance in a binder resin, wherein the photosensitive layer comprises oxytitanium phthalocyanine and General formula [I]
And a disazo compound represented by the following. Embedded image (In the general formula [I], K ₁ and K ₂ each represent a coupler residue containing a hydroxyl group, and K ₁ and K ₂ may be the same or different.) 2. In the X-ray diffraction spectrum, the oxytitanium phthalocyanine has a black angle (2θ ± 0.
2. An oxytitanium phthalocyanine having a crystal form that gives a clear diffraction peak at 2 °) 27.3 °.
The electrophotographic photoconductor described.