JP3448966B2 - Electrophotographic photoreceptor - Google Patents

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 dyes, cyanine dyes, pyrylium dyes, thiapyrylium dyes, polyazo dyes, phthalocyanine 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]

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]

[Chemical 2]

(X represents -O-, -S- or -NR-, wherein R represents a hydrogen atom or an organic group which may be substituted, preferably an alkyl group, an aryl group or an aralkyl group. K ¹ and K ² represent a coupler residue containing a hydroxyl group having a coupling ability.
Represents a benzene ring which may have a substituent. ) The present invention will be described in detail below. As the oxytitanium phthalocyanine used in the present invention, for example, the following general formula [IV]

[0013]

[Chemical 3]

(In the formula, Z represents a halogen atom, and l is 0.
Represents a number from 1 to 1. ). In the general formula [IV], Z is a chlorine atom and l 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 thereof include crystalline oxytitanium phthalocyanine having strong diffraction peaks at °, 23.4 ° and 25.5 °. Hereinafter, oxytitanium phthalocyanine is referred to as "phthalocyanine".

It is represented by the above general formula [I] according to the present invention.
In disazo compounds, K¹, K ²Is the coupling ability
A coupler residue containing a hydroxyl group having, for example:
General formulas [II-a], [II-b], [III-a],
Examples of the groups [III-b], [IV], [V], and [VI]
At least one of the following formulas [II-a] and [II-
b], [III-a] or [III-b]
It is preferable to represent. In addition, hydroxy having coupling ability
A group is a diazodione such as an aromatic ring to which the hydroxyl group is bound.
The group that imparts the ability to couple with an um salt is shown.

[0017]

[Chemical 4]

General formulas [II-a, b], [III-a, b]
In the above, Y represents a divalent group of an aromatic hydrocarbon or a heterocyclic divalent group containing a nitrogen atom in the ring. 2 of aromatic hydrocarbons
Examples of the valent group include a monovalent aromatic hydrocarbon divalent group such as an o-phenylene group; an o-naphthylene group, and a peri- group.
Naphthylene group, 1,2-anthraquinonylene group, 9,1
Examples thereof include divalent groups of fused polycyclic aromatic hydrocarbons such as 0-phenanthrylene group.

Examples of the heterocyclic divalent group containing a nitrogen atom in the ring include, for example, 3,4-pyrazolediyl group and
5 such as 2,3-pyridinediyl group, 5,5-pyrimidinediyl group, 6,7-indazolediyl group, 5,6-benzimidazolediyl group and 6,7-quinolinediyl group
Examples thereof include a nitrogen atom of a 10-membered ring, preferably a heterocyclic divalent group containing 2 or less nitrogen atoms in the ring.

In consideration of sensitivity and durability, Y is o-phenylene group, o-naphthylene group, peri-naphthylene group, 2,3-pyridinediyl group, 4,5-pyrimidinediyl group, and particularly o- A phenylene group and an o-naphthylene group are preferred. The divalent group of these aromatic hydrocarbons used as Y 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, a propoxy group. Group, alkoxy group such as butoxy group; hydroxyl group; nitro group; cyano group; amino group; substituted amino group such as dimethylamino group, diethylamino group, dibenzylamino group;
Halogen atom such as fluorine atom, chlorine atom, bromine atom, iodine atom; carboxyl group; alkoxycarbonyl group such as ethoxycarbonyl group; carbamoyl group; aryloxy group such as phenoxy group; arylalkoxy group such as benzyloxy group; phenyloxycarbonyl Examples thereof include aryloxycarbonyl groups and the like. Of these, an alkyl group, an alkoxy group, a nitro group, a halogen atom, a hydroxyl group and a carboxyl group, particularly a methyl group, a methoxy group, a nitro group, a chlorine atom and a hydroxyl group are preferable.

Since the compound having the group of the formula [II-a] type usually exists as a mixture with the isomer having the group of the formula [II-b] type, in the present invention, the compound of the formula [II-a] is used. It is treated as the same group as the group of the type II-a] and the group of the formula [II-b] type. The same applies to the group of the formula [III-a] type [II
Treated as the same group as the I-b] type group. As the other coupler, the above-mentioned general formulas [II-a], [II-b], [II
In addition to I-a] and [III-b], the following general formulas [V] and [V
Examples thereof include those which can be used as couplers for disazo compounds such as I] and [VII].

[0022]

[Chemical 5]

In the general formula [V], P is condensed with a benzene ring to form a naphthalene ring, anthracene ring, carbazole ring,
Residues necessary for forming a polycyclic aromatic ring or a hetero ring such as a benzcarbazole ring, a dibenzofuran ring, a benzonaphthofuran ring, and a diphenylene sulfide ring are shown.
⁴ and R ⁵ are hydrogen atoms; an alkyl group which may have a substituent, such as a methyl group, an ethyl group, a propyl group and a butyl group; an aralkyl group such as a benzyl group, a phenethyl group and a naphthylmethyl group; a substituent group An aryl group such as a phenyl group, a diphenyl group or a naphthyl group, which may have a carbazole group, a dibenzofuran group, a benzimidazolone group,
A benzthiazole group; a hetero group such as a thiazole group or a pyridine group; or a group which forms a cyclic amino group together with the nitrogen atom to which R ⁴ and R ⁵ are bonded. R ⁴ and R ⁵ may be the same or different from each other, but from the viewpoint of sensitivity, it is preferable that one is a hydrogen atom and the other is a group other than a hydrogen atom.

[0024]

[Chemical 6]

In the general formulas [VI] and [VII], R ⁶
Represents an alkyl group, an aralkyl group or an aryl group which may have a substituent represented by the same examples as R ⁴ and R ⁵ . R ¹ and R ² in the general formula [I] are halogen atoms (eg, fluorine atom, chlorine atom, bromine atom) or optionally substituted alkyl group (eg,
Methyl, ethyl, propyl, iso-propyl, butyl, sec-butyl, t-butyl, hexyl, 2-ethylhexyl, t-octyl, octyl, benzyl, 2-phenylethyl Group, α-naphthylmethyl group, β-naphthylmethyl group, etc.) or an alkoxy group (eg, methoxy group, ethoxy group, butoxy group, 2-methoxyethoxy group, phenoxymethoxy group, etc.), and m and n are 0 to 0. It is an integer of 4.

Examples of X include --O--, --S-- and --NR--. R represents a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group, and an alkyl group, an aryl group,
The aralkyl group may be substituted. Ring A and ring B represent a benzene ring which may have a substituent, and examples of the substituent include a halogen atom or an optionally substituted alkyl group or alkoxy group. Good. These disazo compounds are represented by the following general formula [VIII]

[0027]

[Chemical 7]

(In the formula, X, A and B have the same meanings as those in the above-mentioned general formula [I].) The diamine is tetrazolated by a conventional method and then easily coupled by coupling with a corresponding coupler. You can At least one of the coupler residues K ¹ and K ² in the formula [I] represents a group represented by the above general formulas [II] and [III], but the coupler residues K ¹ and K ² are different from each other. When it is used as a base, two corresponding couplers may be mixed and used.

The coupling reaction may be carried out according to a known method, usually in water and / or an organic solvent such as dimethylformamide and dimethylsulfoxide at a reaction temperature of 30 ° C. or lower for about 1 to 10 hours. Next, the aromatic diamine represented by the general formula [VIII] is specifically produced, for example, by the following method, but the present invention is not limited thereto. The general formula [VII
The aromatic diamine represented by the formula [I] is prepared from the corresponding dinitro compound represented by the following general formula [IX].

[0030]

[Chemical 8]

(In the formula, X, A and B have the same meanings as in the above-mentioned general formula [I].) It is preferably produced under known reduction reaction conditions such as iron powder / hydrochloric acid and stannous chloride / hydrochloric acid. Next, the production examples of the above-mentioned general formula [IX] will be specifically explained, but this is not a limitation as long as it does not exceed the gist of the present invention. In the general formula [IX], the production method when X is —O— is as follows.

A nitrobenzhydrazide represented by the following general formula [Xa] and a nitrocinnamic acid chloride represented by [Xb] are reacted with an inert organic solvent such as toluene, xylene and dimethylformamide. And condensed to produce a diacyl hydrazide compound represented by the following general formula [XI].

[0033]

[Chemical 9]

Next, the diacyl hydrazide [XI] is cyclized by a known dehydration reaction using polyphosphoric acid, fuming sulfuric acid or the like to produce the dinitro compound represented by the above general formula [IX]. When X is -NR- in the general formula [IX], it is produced by reacting a diacyl hydrazide compound represented by the general formula [XI] with H ₂ NR in the presence of a catalyst such as zinc chloride. (Reference example: R. Stoll
e ', Ber. 32, 797 (1899)).

When X is --S-- in the above general formula [IX], it is produced by reacting the diacyl hydrazide represented by the above general formula [XI] with, for example, phosphorus pentasulfide (Reference example: R . Stole 'et al
Ber. 32, 797 (1899), R.I. Stoll
e'et al J. Prakt. Chem. ，
[2], 366 (1904)).

Typical examples of the disazo compound used in the present invention include bisazo compounds shown in Table 1 below. In Table 1, K ¹ -N = N-, K ² -N = N-, ring A in the general formula [I] is used.
And the bonding position of the substituent to the aromatic ring of ring B is shown by the following numbers. However, when there is no substituent, it is not particularly described.

[0037]

[Chemical 10]

For example, when the substituent of A is bonded to the carbon atoms of 2 and 4 by a chlorine atom, it is represented as R ¹ = -Cl, 2,4. In the case of the substituent of B, it is R ² . When the coupler residues K ¹ and K ² are the same group, K ¹ -N = N-
If pK ² -N = N- is attached to a carbon atom of 3 and 8, show a K ^1, K ² in K K-N = N-; expressed as 3,8.

Also, two corresponding different couplers,
For example, by selecting appropriate reaction conditions using k and k ′ and performing the coupling reaction, a mixture of the following two isomers can be obtained in high purity, and at the same time, the compound of K ¹ = K ² = k and the compound of K ¹ = K ² = k can be obtained. ¹
A compound of = K ² = k 'is also mixed.

[0040]

[Chemical 11]

Here, for example, k-N = N-, k'-N =
The case where N- is bonded to the carbon atoms of 3 and 8 respectively, and the case where k'-N = N- and k-N = N- are bonded to the carbon atoms of 8 and 3 respectively, K in the table below
Represented as ¹ , K ² -N = N-; 3,8.

[0042]

[Table 1]

[0043]

[Table 2]

[0044]

[Table 3]

[0045]

[Table 4]

[0046]

[Table 5]

[0047]

[Table 6]

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, that is, an analog signal of a fluorescent lamp, a halogen lamp, a cannon lamp, etc.) which requires a main spectral sensitivity in the visible range, and in the visible range. 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 in the long wavelength side or 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 and dispersed in a dispersion medium, and finally the photosensitive resin is mixed with the 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.

As the dispersion medium, various solvents may be used. 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 for mixing the binder resin with the phthalocyanine and disazo compound particles, for example, a method of dispersing the binder resin in a powder state or adding a polymer solution thereof at the same time during the dispersion treatment of the phthalocyanine and disazo compound particles, or 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 such that the phthalocyanine is used in an amount of 0.05 to 10 parts by weight per 1 part by weight of the disazo compound. 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 make the 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 ~ 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 may 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 a 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.

As the barrier layer, for example, 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.

[0061]

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.

[0062]

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 °, and the exemplified compounds (N
o. 200 parts by weight of n-propanol was added to 8 parts by weight of the disazo compound of 11), and the mixture was pulverized with a sand grind mill for 10 hours and subjected to atomization dispersion treatment. Next, a dispersion was prepared by mixing 5 parts by weight of polyvinyl butyral (Denka Butyral # 6000C, manufactured by Denki Kagaku Kogyo Co., Ltd.) with 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, on this charge generation layer,
56 parts by weight of the hydrazone compound shown below

[0063]

[Chemical 12]

14 parts by weight of a hydrazone compound shown below,

[0065]

[Chemical 13]

And 1.5 parts by weight of the following cyano compound

[0067]

[Chemical 14]

A solution prepared by dissolving 100 parts by weight of a polycarbonate resin (manufactured by Mitsubishi Kasei Co., Ltd., trade name Novarex 7030A) in 1000 parts by weight of 1,4-dioxane was applied by a film applicator, and the film thickness after drying was applied. 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 disazo 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 disazo compound. A photoconductor was created.
The photoconductor thus obtained is referred to as a photoconductor C.

Example 4 In place 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 4 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 15 disazo compounds were used. The photoconductor thus obtained is referred to as a photoconductor F.

Example 7 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 28 disazo compounds were 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 A photoconductor was prepared in the same manner as in Example 1 except that 8 parts by weight of 27 disazo compound was used. 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 3 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.

Comparative Example 1 Instead of the disazo compound used in Example 1, a disazo compound having the following structure

[0078]

[Chemical 15]

Except that 2 parts by weight of oxytitanium phthalocyanine and 8 parts by weight of the above-mentioned disazo compound were used.
A photoconductor was prepared in the same manner as in Example 1. The photoconductor thus obtained is referred to as a comparative photoconductor L.

Comparative Example 2 The same as Example 1 except that the mixing ratio of the oxytitanium phthalocyanine and the disazo compound used in Comparative Example 1 was replaced by 4 parts by weight of oxytitanium phthalocyanine and 6 parts by weight of the disazo compound. A photoconductor was created.
The photoconductor thus obtained is referred to as comparative photoconductor M.

[Evaluation] Obtained photoreceptors A, B, C, D,
E, F, G, H, I, L, and M were measured as half-exposure sensitivity as initial electric characteristics with an electrostatic copying paper tester (Kawaguchi Denki Seisakusho, Model EPA-8100). That is, the photoreceptor was negatively charged by corona discharge in a dark place, and then continuously exposed to monochromatic light of 780 nm, and the surface was -700.
exposure required to decrease from v to -350v (E1 /
2) and residual potential (Vr) were measured. The results are shown in Table-2. From Table-2, the photoconductors A, B, C of the present invention,
It can be seen that D, E, F, G, H, and I have high sensitivity to 780 nm monochromatic light and have lower residual potentials than the comparative photoconductors L and M. 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 disazo compound.

[0082]

[Table 7]

Further, the photoconductor A was attached to a photoconductor spectral sensitivity measuring device, and the spectral sensitivity was measured. That is, the photoreceptor is negatively charged by corona discharge in a dark place, and then monochromatic light dispersed by a monochromator is continuously exposed, and the surface is -7
The exposure amount required to decrease from 00v to -350v (E
1/2) was measured. The results are shown in FIG. 2, where the reciprocal of the measured exposure dose is the sensitivity. From FIG. 2, it can be seen 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 highly sensitive 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.

2 is a spectral sensitivity spectrum diagram of the photoconductor A of Example 1 and the comparative photoconductor K of Comparative Example 1. FIG.

─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-59-71059 (JP, A) JP-A-5-66595 (JP, A) JP-A-3-196049 (JP, A) JP-A-3- 37672 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 5/06 CA (STN) REGISTRY (STN)

Claims (5)

(57) [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 is oxytitanium phthalocyanine. An electrophotographic photosensitive member comprising a disazo compound represented by the following general formula [I]. (In general formula [I], X represents -O- or -S-.
K ¹ and K ² represent a coupler residue containing a hydroxyl group having a coupling ability, and at least one of K ¹ and K ²
Is selected from the group consisting of the following [II-a] to [III-b]
Is a coupled residue. Ring A and ring B represent a benzene ring which may have a substituent. In [II-a] to [III-b], Y is an aromatic hydrocarbon
Elementary divalent group or heterocyclic divalent group containing nitrogen atom in the ring
Represents ) 2. At least a charge-generating material on a conductive support.
Photosensitivity containing quality and charge transport material in binder resin
A photosensitive layer for electrophotography, the photosensitive layer comprising:
Is oxytitanium phthalocyanine and the following general formula
It is characterized by containing a disazo compound represented by [I]
Electrophotographic photoconductor to be considered. [In general formula [I], X represents -O- or -S-.
One of K ¹ and K ² is the following [II-a] to [III-b]
Represents a coupler residue selected from the group consisting of
A selected from the group consisting of [II-a] to [VII] below.
Represents a Plappler residue. Ring A and Ring B have a substituent
Represents a benzene ring which may be present. In [II-a] to [III-b], Y is an aromatic hydrocarbon
Elementary divalent group or heterocyclic divalent group containing nitrogen atom in the ring
Represents In [V], P is condensed with a benzene ring
Shows the residues necessary to form a polycyclic aromatic ring or heterocycle.
R ⁴ and R ⁵ are each independently a hydrogen atom or a substituent.
Optionally having an alkyl group: aralkyl group: substituted
An aryl group which may have a group: represents a hetero group,
Or R ⁴ and R ⁵ are cyclic together with the nitrogen atom to which they are bound
It constitutes an amino group. In [VI] and [VII]
R ⁶ is an alkyl group which may have a substituent, aralkyl
Represents an aryl group or an aryl group. ] 3. In [II-a] to [III-b], Y is
An o-phenylene group which may have a substituent, an o-naphtho
Tylene group, peri-naphthylene group, 2,3-pyridine
Diyl group and 4,5-pyrimidinediyl group
2. A divalent group selected from the group consisting of:
2. The electrophotographic photoreceptor according to 2. 4. R in [V] ^Four And R ^Five One side is hydrogen
Characterized by being atoms and the other being a non-hydrogen atom
The electrophotographic photosensitive material according to claim 1.
body. 5. The oxytitanium phthalocyanine has a black angle (2θ ± 0.2) in an X-ray diffraction spectrum.
5.) The crystalline form having a clear diffraction peak at 27.3.degree.
The electrophotographic photoreceptor according to any one of the above .