JPH0934149A - Electrophotographic photoreceptor, process cartridge with the same and electrophotographic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure high sensitivity, superior potential stability and superior photomemory characteristics by forming a photosensitive layer contg. oxytitanium phthalocyanine and a specified azo pigment. SOLUTION: In this electrophotographic photoreceptor with a photosensitive layer on the electrically conductive substrate, the photosensitive layer contains oxytitanium phthalocyanine and an azo pigment represented by formula I, wherein Ar is optionally substd. arom. cyclic hydrocarbon group which may bond through a bonding group or an optionally substd. heterocyclic group which may bond through a bonding group, Cp is a residue of a coupler having a phenolic hydroxyl group, at least one of Cp's is a residue of a coupler represented by formula II and (n) is an integer of 2-4. In the formula II, A is an optinally substd. divalent arom. cyclic hydrocarbon group or an optionally substd. divalent heterocyclic group contg. N in the ring.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member having a photosensitive layer containing a specific charge generating material, a process cartridge having the electrophotographic photosensitive member, and an electrophotographic apparatus.

[0002]

2. Description of the Related Art An electrophotographic photosensitive member using an organic photoconductor has been developed by developing a function-separated photosensitive member in which a charge generating layer containing a charge generating material and a charge transporting layer containing a charge transporting material are laminated. Significant improvements in durability have been made,
It has come into widespread practical use. Particularly in recent years, non-impact printers to which electrophotographic technology is applied have become widespread in place of conventional impact printers as terminal printers. These are laser beam printers that mainly use laser light as a light source, and a semiconductor laser is used as the light source in terms of cost, size of the device, and the like. Since the oscillation wavelength of the semiconductor laser mainly used at present is 790 ± 20 nm, which is a long wavelength, development of an electrophotographic photoreceptor having sufficient sensitivity in a long wavelength region has been advanced.

Metal-free phthalocyanines and metal phthalocyanines have been known as materials having sensitivity in such a long wavelength region, and have been put into practical use as charge generating materials. Among phthalocyanine compounds, oxytitanium phthalocyanine has extremely high sensitivity.

However, an electrophotographic photosensitive member using oxytitanium phthalocyanine is desired to have more excellent potential stability and more excellent photomemory (potential decay of a fluorescent lamp irradiation portion). Therefore, methods such as thinning the charge generating layer and reducing the proportion of oxytitanium phthalocyanine in the charge generating layer have been proposed, but such measures lead to a decrease in sensitivity.

Further, it has been proposed to use oxytitanium phthalocyanine and a bisazo pigment for the purpose of obtaining panchromatic sensitivity, but these bisazo pigments have not been found to have the effect of improving the above characteristics. I can't.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrophotographic photoreceptor having high sensitivity, excellent potential stability and excellent photomemory characteristics.

Another object of the present invention is to provide a process cartridge and an electrophotographic apparatus having the above electrophotographic photosensitive member.

[0008]

That is, the present invention provides an electrophotographic photosensitive member having a photosensitive layer on a conductive support, wherein the photosensitive layer is oxytitanium phthalocyanine and the following formula (1).

[0009]

[Outside 3] [In the formula, Ar is a substituted or unsubstituted aromatic hydrocarbon ring group which may be bonded via a bonding group or a substituted or unsubstituted heterocyclic group which may be bonded via a bonding group. Cp represents a coupler residue having a phenolic hydroxyl group, and at least one of the Cp is represented by the following formula (2)

[0010]

[Outside 4] (In the formula, A represents a divalent group of a substituted or unsubstituted aromatic hydrocarbon ring or a divalent group of a substituted or unsubstituted heterocyclic ring containing a nitrogen atom in the ring). Shows a group and n shows the integer of 2-4. ] It is an electrophotographic photosensitive member characterized by containing the azo pigment shown by these.

The present invention also provides a process cartridge and an electrophotographic apparatus having the above electrophotographic photosensitive member.

According to the present invention having the above-mentioned constitution, in addition to obtaining excellent potential stability and excellent photomemory characteristics, this particular azo pigment has a chemical property although it has no sensitivity in the vicinity of 800 nm. It is also possible to obtain an effect that the sensitivity of oxytitanium phthalocyanine near 800 nm is sensitized by the sensitizing action.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The oxytitanium phthalocyanine used in the present invention has the following structural formula.

[0014]

[Outside 5] (In the formula, X ₁ , X ₂ , X ₃ and X ₄ represent C1 or Br, and k, m, p and r are integers of 0 to _4. )

The crystal form of the oxytitanium phthalocyanine may be any type, but it is not disclosed in JP-A-62-67094.
A type described in Japanese Unexamined Patent Publication No. 61-239248, B type in Japanese Unexamined Patent Publication No. 61-239248, I type in Japanese Unexamined Patent Publication No. 3-128973, and Japanese Unexamined Patent Publication No. 64-17066. Y-type crystals are preferable, and I-type crystals are particularly preferable. The CuKα characteristic X-ray diffraction diagram of each crystal form is shown in FIG.
This is shown in FIGS. 3, 1 and 4. The synthesis of oxytitanium phthalocyanine and the production of the above crystal form can be carried out by a known method described in the above-mentioned patent application publication, etc.

On the other hand, specific examples of Ar in the formula (1) include benzene, naphthalene, fluorene, phenanthrene,
Aromatic hydrocarbon rings such as anthracene and pyrene; heterocycles such as furan, thiophene, pyridine, indole, benzothiazole, carbazole, acridone, dibenzothiophene, benzoxazole, oxadiazole and thiazole; and further aromatic hydrocarbon rings or Heterocycles bonded directly or through an aromatic or non-aromatic group, such as biphenyl, binaphthyl, diphenylamine, triphenylamine, N-methyldiphenylamine, fluorenone, phenanthrenequinone,
Anthraquinone, benzanthrone, terphenyl, diphenyloxadiazole, stilbene, distyrylbenzene, azobenzene, azoxybenzene, phenylbenzoxazole, diphenylmethane, diphenylsulfone, diphenyl ether, benzophenone, tetraphenyl-p-phenylenediamine, tetraphenylbenzidine, N-phenyl-2-pyridylamine and N, N
Groups such as -diphenyl-2-pyridylamine.

The substituent which Ar may have is an alkyl group such as methyl, ethyl, propyl and butyl;
Examples thereof include alkoxy groups such as methoxy, ethoxy and propoxy; halogen atoms such as fluorine, chlorine, iodine and bromine; alkylamino groups such as dimethylamino and diethylamino; hydroxyl group; nitro group; cyano group; and halomethyl group.

Specific examples of A in the formula (2) include o-phenylene, 2,3-naphthylene, 2,3-pyrazinediyl, 3,4-pyrazolediyl, 2,3-pyridinediyl and 4,5-. Groups such as pyridinediyl and 4,5-imidazolediyl are mentioned.

The substituent which A may have is an alkyl group such as methyl, ethyl, propyl and butyl; an alkoxy group such as methoxy, ethoxy and propoxy;
A halogen atom such as fluorine, chlorine, iodine and bromine; a nitro group; a cyano group; and a halomethyl group.

Of these, A is preferably unsubstituted o-phenylene.

In Cp in the formula (1), groups represented by the following formulas (3) to (8) are preferable examples of the coupler residue which may coexist in addition to the coupler residue represented by the formula (2). Is mentioned.

[0022]

[Outside 6]

[0023]

[Outside 7]

X in the formulas (3), (4), (5) and (6) is necessary for bonding with a benzene ring to form a substituted or unsubstituted aromatic ring or a substituted or unsubstituted heterocycle. Group of atoms, and specific examples of the aromatic ring and the heterocyclic ring include naphthalene ring, anthracene ring, carbazole ring,
Examples thereof include a benzcarbazole ring and a dibenzofuran ring. Y in the formula (8) represents a divalent group of a substituent or an unsubstituted aromatic hydrocarbon ring or a divalent group of a substituted or unsubstituted heterocycle containing a nitrogen atom in the ring, and specifically, o-phenylene, o-naphthylene, perinaphthylene,
1,2-anthrylene, 3,4-pyrazolediyl,
2,3-pyridinediyl, 4,5-pyridinediyl,
Examples thereof include groups such as 6,7-indazolediyl and 6,7-quinolinediyl, and R ₁ and R ₂ in formulas (3) and (4) are each a hydrogen atom, a substituted or unsubstituted alkyl group,
A substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group or a substituted or unsubstituted heterocyclic group, and R ₁ and R ₂ are bonded to each other to form a substituted or unsubstituted cyclic group via a nitrogen atom. R ₃ in formulas (5) and (6) may form an amino group, and R ₃ is a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group or a substituted group. Or an unsubstituted heterocyclic group represented by the formula (7)
R ₄ represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group or a substituted or unsubstituted heterocyclic group, and the alkyl group is methyl, Groups such as ethyl and propyl; groups such as phenyl, naphthyl and anthryl as aryl groups; groups such as benzyl and phenethyl as aralkyl groups; groups such as pyridyl, thienyl, carbazolyl, benzimidazoline and benzothiazolyl as heterocyclic groups; Examples of the cyclic amino group containing a nitrogen atom in the ring include groups such as pyrrole, pyrroline, pyrrolidine, pyrrolidone, indole, indoline, carbazole, imidazole, pyrazole, pyrazoline, oxazine and phenoxazine. Further, as the substituent, a halogen atom such as fluorine, chlorine, iodine and bromine; an alkyl group such as methyl, ethyl and propyl; an alkoxy group such as methoxy and ethoxy; an alkylamino group such as dimethylamino and diethylamino;
A phenylcarbamoyl group; a nitro group; a cyano group; and a halomethyl group such as trifluoromethyl.
Z in the formulas (3) and (5) represents an oxygen atom or a sulfur atom, and m represents 0 or 1.

In the formula (2), n represents an integer of 2 to 4, but it is preferably 2 or 3.

Next, preferred specific examples of the azo pigment represented by the formula (1) of the present invention will be given, but the azo pigment used in the present invention is not limited thereto. In addition, the exemplified pigment first shows a basic type, and only a changed portion is described to represent a specific structure.

Since the coupler having the coupler residue represented by the formula (2) is usually obtained as a mixture of isomers at the time of synthesis as described later, specific examples are also exemplified as the mixture. For example, in Pigment Example 1

[0028]

[Outside 8] Is used to indicate that the azo pigment of Pigment Example 1 is a mixture of the following compounds.

[0029]

[Outside 9]

[0030]

[Outside 10]

[0031]

[Outside 11]

[0032]

[Outside 12]

[0033]

[Outside 13]

[0034]

[Outside 14]

[0035]

[Outside 15]

[0036]

[Outside 16]

[0037]

[Outside 17]

[0038]

[Outside 18]

[0039]

[Outside 19]

[0040]

[Outside 20]

[0041]

[Outside 21]

[0042]

[Outside 22]

[0043]

[Outside 23]

[0044]

[Outside 24]

[0045]

[Outside 25]

[0046]

[Outside 26]

In the present invention, among these, it is particularly preferable that all Cp are coupler residues represented by the formula (2). Further, Pigment Examples 1, 3, 4, 5, 6, 28 and 29 are preferable.

The coupler having the coupler residue represented by the above formula (2) is synthesized by dehydration condensation of hydroxy-1,8-naphthalic anhydride and the corresponding aminoarylcarboxylic acid amide in a suitable solvent. it can. Solvents used include nitrobenzene, dichlorobenzene,
Examples thereof include trichlorobenzene and xylene, and phosphorus oxychloride or polyphosphoric acid may be added as a condensing agent. The synthesized coupler having a coupler residue represented by the formula (2) is obtained as a mixture of isomers represented by the following formulas (2-a) and (2-b), but in the present invention, The isomers of can also be used.

[0049]

[Outside 27]

Synthesis Example 1 (Synthesis of Coupler) 10.0 g of 3-hydroxy-1,8-naphthalic anhydride
And o-aminobenzamide (7.0 g) were added to 130 ml of nitrobenzene, and the mixture was heated under reflux for 12 hours. After allowing to cool, the precipitate was filtered, dispersed and washed with toluene and then with methanol, and reprecipitation with an N, N-dimethylformamide-methanol-based solvent was repeated twice, followed by dispersion and washing with methanol again, and then drying. The above formulas (2-a) and (2-b)
A mixture of couplers of 3.5 was obtained. mp310
˜315 ° C., mass spectrum: m / z = 314

The azo pigment represented by the above formula (1) is
(A) Diazotization of the corresponding amine by a conventional method, and coupling with a coupler having a coupler residue represented by the formula (2) in the presence of an alkali in an aqueous system, or (b) diazonium salt with a borofluoride salt or After conversion to a zinc chloride double salt, etc., it can be easily carried out by coupling with the coupler in the presence of a base such as sodium acetate, triethylamine and N-methylmorpholine in an organic solvent such as N, N-dimethylformamide and dimethylsulfoxide. Can be synthesized. When synthesizing a disazo pigment in which a coupler residue other than the coupler residue represented by the above formula (2) coexists in the molecule, it is first represented by the above formula (2) with respect to 1 mol of the tetraazonium salt (a). Synthesized by coupling 1 mol of a coupler having a coupler residue and then coupling 1 mol of another coupler, or protecting one amino group of (b) or diamine with an acetyl group or the like, Diazotizing this, coupling the coupler having the coupler residue represented by the above formula (2), hydrolyzing the protecting group with hydrochloric acid, etc., diazotizing this again, and coupling the other coupler. Can be synthesized by. A trisazo pigment or a tetrakisazo pigment in which a coupler residue other than the coupler residue represented by the formula (2) coexists in the molecule can be similarly synthesized.

Synthesis Example 2 (Synthesis of Pigment 1) 150 ml of water in a 300 ml beaker,
20 ml (0.23 mol) of concentrated hydrochloric acid and 7.3 g (0.032 mol) of the following diamine compound

[0053]

[Outside 28] And cooled to 0 ° C., 4.6 g of sodium nitrite (0.
067 mol) in 10 ml of water,
The solution was added dropwise over 10 minutes while maintaining the liquid temperature at 2 ° C or lower. Fifteen
After stirring for 1 minute, carbon filtration was performed, and a solution prepared by dissolving 10.5 g (0.096 mol) of sodium borofluoride in 90 ml of water was added dropwise to this solution, and the precipitated borofluoride salt was collected by filtration and washed with cold water. After that, it was washed with acetonitrile and dried under reduced pressure at room temperature. The yield was 12.8 g, and the yield was 94%.

Next, 3 liters of DMF was placed in a 5 liter beaker, 13.2 g (0.042 mol) of the mixture of couplers represented by the formulas 2-a and 2-b was dissolved by heating and the liquid temperature was 5 ° C. After cooling to 8.5, 8.5 g (0.020 mol) of the borofluoride salt obtained above was dissolved, and then 5.1 g (0.050 mol) of triethylamine was added dropwise over 5 minutes. After stirring for 2 hours, the precipitated pigment was collected by filtration and DMF was added.
, And then freeze-dried. Yield 1
The amount was 4.2 g, and the yield was 81%.

The electrophotographic photosensitive member of the present invention has a photosensitive layer containing oxytitanium phthalocyanine and the azo pigment represented by the formula (1) on a conductive support. The form of the photosensitive layer may be any known form, but a layer containing oxytitanium phthalocyanine and the azo pigment represented by the formula (1) is used as a charge generating layer, and a charge transporting layer containing a charge transporting substance thereon. A function-separated type photosensitive layer in which is laminated is particularly preferable.

The charge generation layer of the present invention may be a layer containing both oxytitanium phthalocyanine and the azo pigment represented by the general formula (1), or may be a layer in which layers containing each of them are laminated. .

When the oxytitanium phthalocyanine and the azo pigment are mixed, the oxytitanium phthalocyanine / azo pigment (weight ratio) is preferably 95/5 to 70/30. If the mixing ratio is greater than 95/5, the desired improvement effect may be insufficient, and conversely, if the mixing ratio is less than 70/30, the sensitivity on the long wavelength side may decrease.

When the charge generation layer containing oxytitanium phthalocyanine and the charge generation layer containing azo pigment are laminated, oxytitanium phthalocyanine is contained even if the layer containing azo pigment is in contact with the charge transport layer. The layer may be in contact with the charge transport layer, but the latter mode is preferable because the effect of the present invention is greater. The film thickness of the layer containing oxytitanium phthalocyanine is preferably 0.1 to 0.5 μm, but the film thickness of the layer containing the azo pigment does not need to be too thick.
A sufficient effect can be obtained at about 0.2 μm.

For the charge generation layer, oxytitanium phthalocyanine and the azo pigment of the present invention are vapor-deposited on a conductive support, or a solution prepared by dispersing them together with a binder resin in a suitable solvent is known on the conductive support. It can be formed by coating by the method, and its film thickness is 5μ.
It is preferably m or less, and particularly preferably 0.1 to 1 μm. At this time, the binder resin used is selected from a wide range of insulating resins or organic photoconductive polymers, but polyvinyl butyral, polyvinyl benzal, polyarylate, polycarbonate, polyester, phenoxy resin, cellulosic resin, acrylic resin and Polyurethane or the like is preferable, and the amount thereof used is preferably 80% by weight or less, and particularly preferably 40% by weight or less, based on the total weight of the charge generation layer. The solvent used also dissolves the above resin,
It is preferable to select a charge transport layer or an undercoat layer described later from those which do not dissolve. Specifically, ethers such as tetrahydrofuran and 1,4-dioxane; ketones such as cyclohexanone and methyl ethyl ketone; N, N
Amides such as dimethylformamide; esters such as methyl acetate and ethyl acetate; aromatics such as toluene, xylene and chlorobenzene; alcohols such as methanol, ethanol and 2-propanol; and chloroform, methylene chloride, dichloroethylene. And aliphatic halogenated hydrocarbons such as carbon tetrachloride and trichloroethylene.

The charge transport layer is laminated on or under the charge generation layer, and is formed by applying a solution in which a charge transport material is dissolved in a solvent together with a suitable binder resin as necessary. The film thickness is preferably 5 to 40 μm, and particularly preferably 15 to 30 μm.

The charge transport material is roughly classified into an electron transport material and a hole transport material. Examples of the electron transporting substance include 2,4,7-trinitrofluorenone, 2,4,5,7
-Electron withdrawing substances such as tetranitrofluorenone, chloranil, and tetracyanoquinodimethane, and those obtained by polymerizing these electron withdrawing substances. As the hole-transporting substance, polycyclic aromatic compounds such as pyrene and anthracene; carbazole, indole, imidazole, oxazole, thiazole, oxadiazole, pyrazole, pyrazoline, thiadiazole and triazole compounds A heterocyclic compound such as p-
Hydrazone compounds such as diethylaminobenzaldehyde-N, N-diphenylhydrazone and N, N-diphenylhydrazino-3-methylidene-9-ethylcarbazole; tri-p-tolylamine, 4- (di-p-tolylamino) -biphenyl, 2- (di-p-tolyl) -amino-9,9'-dimethylfluorene and 1-di-p-
Triarylamine compounds such as tolyl-aminopyrene; α-phenyl-4′-N, N-diphenylaminostilbene and 5- [4-di-p-tolylamino) benzylidene] -5H-dibenzo [a, d] cycloheptene Styryl compounds; benzidine compounds; triarylmethane compounds; triphenylamine compounds; or polymers having groups of these compounds in the main chain or side chains (eg poly-N-vinylcarbazole, polyvinylanthracene, etc.) ) Is mentioned. In addition to these organic charge transport materials, selenium, selenium-tellurium,
Inorganic materials such as amorphous silicon and cadmium sulfide can also be used. These charge transport materials can be used alone or in combination of two or more. When the charge transport material does not have a film forming property, a suitable binder resin can be used. Specifically, insulating resin such as acrylic resin, polyarylate, polyester, polycarbonate, polystyrene, acrylonitrile-styrene copolymer, polyacrylamide, polyamide, chlorinated rubber or organic photoconductive material such as poly-N-vinylcarbazole and polyvinylanthracene. And the like.

As the conductive support used in the present invention, for example, aluminum, aluminum alloy, copper, zinc, stainless steel, vanadium, molybdenum, chromium, titanium, nickel, indium, gold and platinum are used. In addition, plastics (eg polyethylene,
Support such as polypropylene, polyvinyl chloride, polyethylene terephthalate and acrylic resin) or conductive particles (such as carbon black and silver particles) coated on the above plastic, metal or alloy with a suitable binder resin. Alternatively, a support in which plastic or paper is impregnated with conductive particles can be used. Examples of the shape include a drum shape, a sheet shape, and a belt shape, but it is preferable that the shape is most suitable for the electrophotographic apparatus to which it is applied.

In the present invention, an undercoat layer having a barrier function and an adhesive function may be provided between the conductive support and the photosensitive layer. The subbing layer can be formed of casein, polyvinyl alcohol, nitrocellulose, polyamide (nylon 6, nylon 66, nylon 610, copolymerized nylon and alkoxymethylated nylon, etc.), polyurethane, aluminum oxide and the like. The thickness of the undercoat layer is preferably 5 μm or less, particularly preferably 0.1 μm.
1 to 3 μm is preferable.

Another specific example of the present invention is an electrophotographic photosensitive member having a photosensitive layer containing oxytitanium phthalocyanine, the azo pigment of the present invention and the above-mentioned charge transport material in the same layer. At this time, a charge transfer complex composed of poly-N-vinylcarbazole and trinitrofluorenone can be used as the charge transport material. The electrophotographic photoreceptor of this example has a solution obtained by dispersing and dissolving oxytitanium phthalocyanine, the azo pigment of the present invention, and the above-described charge transport material or charge transfer complex in a suitable resin solution on a conductive support. It can be formed by applying the composition on a substrate and drying.

In any of the electrophotographic photoreceptors, the crystal form of the azo pigment represented by the formula (1) may be amorphous or crystalline, and if necessary, it may be represented by the formula (1). It is also possible to use two or more kinds of the azo pigments shown in combination or to use in combination with a known charge generating material.

Further, in the present invention, a layer containing a resin and, if necessary, a conductive substance, a charge transport material and the like can be further provided as a protective layer on the photosensitive layer.

The electrophotographic photoreceptor of the present invention can be used not only in electrophotographic copying machines but also in laser beam printers, C
RT printer, LED printer, LCD printer,
It can be widely used in electrophotographic applications such as laser plate making and facsimile.

FIG. 5 shows a schematic structure of an electrophotographic apparatus having a process cartridge having the electrophotographic photosensitive member of the present invention.

In FIG. 1, reference numeral 1 denotes a drum-shaped electrophotographic photosensitive member of the present invention, which is driven to rotate around a shaft 2 at a predetermined peripheral speed in a direction indicated by an arrow. The photoreceptor 1 rotates during the rotation process.
The peripheral surface of the primary charging means 3 is uniformly charged with a positive or negative predetermined potential, and then image exposure light 4 from an image exposure means (not shown) such as slit exposure or laser beam scanning exposure is received. Thus, an electrostatic latent image is sequentially formed on the peripheral surface of the photoconductor 1.

The formed electrostatic latent image is then developed.
The toner-developed image is developed by the toner, and the developed toner-developed image is transferred to the transfer material 7 which is fed between the photosensitive member 1 and the transfer unit 6 in synchronization with the rotation of the photosensitive member 1 from a sheet feeding unit (not shown). The images are sequentially transferred by the transfer means 6.

The transfer material 7 which has undergone the image transfer is separated from the photoreceptor surface, introduced into the image fixing means 8 and subjected to image fixing, thereby being printed out of the apparatus as a copy.

After the transfer of the image, the surface of the photoreceptor 1 is cleaned by removing the untransferred toner by the cleaning means 9, and is further cleaned by a pre-exposure light 10 from a pre-exposure means (not shown).
Is used for image formation repeatedly after the charge removal processing. When the primary charging unit 3 is a contact charging unit using a charging roller or the like, pre-exposure is not necessarily required.

In the present invention, among the constituent elements such as the electrophotographic photosensitive member 1, the primary charging means 3, the developing means 5 and the cleaning means 9, a plurality of components are integrally combined as a process cartridge, The process cartridge may be detachably attached to the main body of the electrophotographic apparatus such as a copying machine or a laser beam printer. For example, at least one of the primary charging unit 3, the developing unit 5, and the cleaning unit 9 is supported together with the photosensitive member 1 into a cartridge, and the process cartridge 11 which can be attached to and detached from the apparatus main body by using a guide unit such as a rail 12 of the apparatus main body. Can be

When the electrophotographic apparatus is a copying machine or a printer, the image exposure light 4 is reflected or transmitted from the original, or the original is read by a sensor and converted into a signal. Laser beam scanning,
Light emitted by driving the LED array, driving the liquid crystal shutter array, and the like.

[0075]

【Example】

Example 1 50 parts of titanium oxide powder coated with tin oxide containing 10% antimony oxide (parts by weight, the same applies hereinafter), 25 parts of resol type phenol resin, 20 parts of methyl cellosolve, 5 parts of methanol and silicone oil (polyester). Dimethyl siloxane polyoxyalkylene copolymer, weight average molecular weight 3000) 0.002 part was dispersed for 2 hours by a sand mill using 1 mmφ glass beads. This solution was applied onto an aluminum cylinder (80 mmφ × 360 mm) by dip coating and dried at 140 ° C. for 30 minutes to form a conductive layer having a film thickness of 20 μm.

On this conductive layer, 6-66-610-12
A solution prepared by dissolving 5 parts of a quaternary polyamide copolymer in a mixed solvent of 70 parts of methanol and 25 parts of butanol was applied by dip coating and dried to form an undercoat layer having a film thickness of 1 μm.

CuKα characteristic X-ray diffraction flag angles (2θ ± 0.2 °) of 9.0 °, 14.2 °, and 23.9.
7 parts of I-type oxytitanium phthalocyanine (diffraction pattern is shown in FIG. 1) having characteristic peaks at 2 ° and 27.1 ° and 3 parts of the azo pigment of Pigment Example 1 are polyvinyl butyral (trade name S-REC BX-1, Sekisui). (Chemical Co., Ltd.)
10 parts was added to a solution prepared by dissolving 400 parts of cyclohexanone. This solution was dispersed for 3 hours by a sand mill using 1 mmφ glass beads, and further diluted with 400 parts of ethyl acetate. The obtained solution was applied onto the undercoat layer by dip coating and dried at 80 ° C. for 10 minutes to form a charge generation layer having a film thickness of 0.25 μm.

Next, the charge transport material 1 having the following structural formula
0 copy

[0079]

[Outside 29] 10 parts of bisphenol Z type polycarbonate (weight average molecular weight 49000) was dissolved in 60 parts of chlorobenzene. This solution was applied onto the charge generation layer by dip coating and dried at 110 ° C. for 1 hour to form a charge transport layer having a film thickness of 20 μm, thereby preparing an electrophotographic photoreceptor.

Comparative Example 1 An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the amount of I-type oxytitanium phthalocyanine was 10 parts and no azo pigment was used.

Comparative Example 2 An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the azo pigment was not used.

Comparative Example 3 An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the azo pigment represented by the following structural formula was used instead of the azo pigment.

[0083]

[Outside 30]

The electrophotographic photosensitive members prepared in Example 1 and Comparative Examples 1, 2 and 3 were mounted on a laser beam printer (trade name: LBP-SX, manufactured by Canon Inc.) to evaluate the characteristics. First, the dark potential is set to -700V, and
The amount of laser light at which the bright portion potential was -150 V, that is, the sensitivity was measured by irradiating with a laser light of 2 nm. Also, A4
The amount of change in the dark potential (ΔV _D ) and the amount of change in the bright potential (ΔV _L ) when 5,000 sheets were continuously printed were measured. A negative value of the amount of change indicates that the absolute value of the electric charge has decreased after printing, and a positive value indicates that it has increased.

Further, the photo memory characteristics were evaluated. Specifically, first, a fluorescent lamp (trade name: FV) was added to the electrophotographic photosensitive members prepared in Example 1 and Comparative Examples 1, 2 and 3.
Using an L18 type white lamp, manufactured by Matsushita Electric Co., Ltd., light was partially irradiated for 5 minutes at an illuminance of 1500 lux (a non-light-irradiated portion was shielded from light). After irradiation with light, the mixture was left at room temperature for 5 minutes and then mounted on the above laser beam printer to measure the potential difference between the light portion potential of the non-light irradiation portion and the light portion of the light irradiation portion (photo memory = | potential of non-light irradiation portion-light Irradiation potential |).

The above results are shown in Table 1.

[0087]

[Table 1]

As can be seen from these results, in Example 1, as compared with Comparative Example 1, although the content of oxytitanium phthalocyanine was small, the same sensitivity was obtained, and the repeating characteristics and the photomemory characteristics were improved. . On the other hand, in Comparative Example 2, since the content of oxytitanium phthalocyanine is small and the azo pigment is not used, the sensitivity is considerably lowered, and the repetitive characteristics and the photomemory characteristics are not improved so much. Further, the effect of the present invention is not obtained in Comparative Example 3 using the conventional bisazo pigment.

Example 2 A solution for a charge generation layer was obtained in the same manner as in Example 1 except that the dispersion liquid of oxytitanium phthalocyanine and the dispersion liquid of azo pigment were separately prepared. At this time, the ratio (weight ratio) of pigment / binder resin in each solution was set to 10/10.

A conductive layer and an undercoat layer were formed in the same manner as in Example 1, the azo pigment dispersion was applied onto the undercoat layer to a film thickness of 0.1 μm, dried, and further coated. A dispersion of oxytitanium phthalocyanine to a film thickness of 0.2
Two charge generation layers were formed by coating so as to have a thickness of 5 μm and drying. The charge transport layer was formed in the same manner as in Example 1 to prepare an electrophotographic photoreceptor.

Example 3 Example 2 was repeated except that the order of formation of the charge generating layer of azo pigment and the charge generating layer of oxytitanium phthalocyanine was reversed.
An electrophotographic photoreceptor was prepared in exactly the same manner as described above.

The electrophotographic photosensitive members prepared in Examples 2 and 3 were evaluated in the same manner as in Example 1. Table 2 shows the results.
For comparison, the results of the electrophotographic photosensitive member prepared in Comparative Example 1 in which the azo pigment is not contained in the charge generation layer are also shown.

[0093]

[Table 2]

As can be seen from these results, in the present invention, the repeating characteristics and the photomemory characteristics are improved, but it is better to provide the charge generating layer containing the azo pigment on the side of the conductive support in view of sensitivity and the like. More preferable.

Examples 4, 5 and 6 In place of type I oxytitanium phthalocyanine, X-ray diffraction patterns are shown in FIGS. 2, 3 and 4, respectively.
Electrophotographic photoreceptors corresponding to Examples 4, 5 and 6 were prepared in the same manner as in Example 1 except that the oxytitanium phthalocyanine of the B-type, B-type and Y-type was used.

Comparative Examples 4, 5 and 6 I type oxytitanium phthalocyanine was added to the above A type and B type.
Electrophotographic photoreceptors corresponding to Comparative Examples 4, 5 and 6 were prepared in the same manner as in Comparative Example 1 except that the type and Y type oxytitanium phthalocyanines were used.

The electrophotographic photosensitive members prepared in Examples 4, 5, and 6, Comparative Example 4, Comparative Example 5, and Comparative Example 6 were evaluated in the same manner as in Example 1. The results are shown in Table 3.

[0098]

[Table 3]

From these results, it can be seen that the present invention has an effect regardless of the crystal form of oxytitanium phthalocyanine.

Examples 7 to 16 The azo pigments of Pigment Example 1 were converted into Pigment Examples 4, 29, 3 and 2, respectively.
Electrophotographic photoreceptors corresponding to Examples 7 to 16 were prepared and evaluated in the same manner as in Example 1 except that the azo pigments of 8, 5, 20, 24, 26, 34 and 37 were used. Table 4 shows the results
Shown in The results of Example 1 and Comparative Example 1 are also shown for comparison.

[0101]

[Table 4]

Examples 17 to 20 Electrophotographic photoreceptors corresponding to Examples 17 to 20 were prepared in the same manner as in Example 1 except that the compounds having the following structural formulas were used instead of the charge transport materials. Charge transport material used in Example 17

[0103]

[Outside 31] Charge transport material used in Example 18

[0104]

[Outside 32] Charge transport material used in Example 19

[0105]

[Outside 33] Charge transport material used in Example 20

[0106]

[Outside 34]

Comparative Examples 7 to 10 Comparative Example 7 was carried out in the same manner as Comparative Example 1 except that the charge transporting material was replaced with the charge transporting material used in Examples 17 to 20, respectively.
Electrophotographic photoreceptors corresponding to Nos. 10 to 10 were prepared.

The electrophotographic photosensitive members prepared in Examples 17 to 20 and Comparative Examples 7 to 10 were evaluated in the same manner as in Example 1. Table 5 shows the results.

[0109]

[Table 5]

From these results, it can be seen that the present invention has an effect regardless of the charge transport material used.

[0111]

As described above, according to the present invention, it is possible to provide a process cartridge and an electrophotographic apparatus having an electrophotographic photosensitive member having high sensitivity, excellent potential stability and excellent photomemory characteristics. It was

[Brief description of drawings]

FIG. 1: CuK of type I oxytitanium phthalocyanine
It is an α characteristic X-ray diffraction diagram.

FIG. 2 CuK of A-type oxytitanium phthalocyanine
It is an α characteristic X-ray diffraction diagram.

FIG. 3: CuK of B-type oxytitanium phthalocyanine
It is an α characteristic X-ray diffraction diagram.

FIG. 4 CuK of Y-type oxytitanium phthalocyanine
It is an α characteristic X-ray diffraction diagram.

FIG. 5 is a diagram showing a schematic configuration of an electrophotographic apparatus having a process cartridge having the electrophotographic photosensitive member of the present invention.

Claims (7)

[Claims] 1. An electrophotographic photoreceptor having a photosensitive layer on a conductive support, the photosensitive layer comprising oxytitanium phthalocyanine and the following formula (1): [In the formula, Ar is a substituted or unsubstituted aromatic hydrocarbon ring group which may be bonded via a bonding group or a substituted or unsubstituted heterocyclic group which may be bonded via a bonding group. Cp represents a coupler residue having a phenolic hydroxyl group, and at least one of the Cp is represented by the following formula (2): (In the formula, A represents a divalent group of a substituted or unsubstituted aromatic hydrocarbon ring or a divalent group of a substituted or unsubstituted heterocyclic ring containing a nitrogen atom in the ring). Shows a group and n shows the integer of 2-4. ] An electrophotographic photoreceptor comprising an azo pigment represented by 2. The electrophotographic photosensitive member according to claim 1, wherein all Cp are represented by the formula (2). 3. The electrophotographic photosensitive member according to claim 1, wherein A is an unsubstituted o-phenylene. 4. The electrophotographic photosensitive member according to claim 1, wherein n is 2 or 3. 5. The oxytitanium phthalocyanine is Cu
Bragg angle (2θ ± 0.2 in Kα characteristic X-ray diffraction
°) 9.0 °, 14.2 °, 23.9 ° and 27.1
The electrophotographic photoreceptor according to claim 1, which has a characteristic peak at °. 6. An electrophotographic apparatus integrally supporting at least one unit selected from the group consisting of the electrophotographic photosensitive member according to claim 1 and a charging unit, a developing unit and a cleaning unit. A process cartridge characterized by being removable from the main body. 7. An electrophotographic apparatus comprising the electrophotographic photosensitive member according to claim 1, a charging unit, an exposing unit, a developing unit and a transferring unit.