JP4322345B2 - Mixed crystal composition, electrophotographic photosensitive member, electrophotographic method and electrophotographic apparatus using the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a novel organic pigment composition and a production method thereof, a photoconductor using the same, an electrophotographic method and an electrophotographic apparatus, and more particularly, a novel mixed crystal composition comprising titanyl phthalocyanine and an azo pigment and The present invention relates to a production method, a photoconductor using a novel mixed crystal composition, an electrophotographic method, and an electrophotographic apparatus.
[0002]
[Prior art]
In recent years, there has been a remarkable development of information processing system machines using electrophotography. In particular, an optical printer that converts information into a digital signal and records information by light is markedly improved in print quality and reliability. This digital recording technique is applied not only to printers but also to ordinary copying machines, and so-called digital copying machines have been developed. In addition, since a variety of information processing functions are added to a conventional copying machine equipped with this digital recording technology for analog copying, it is expected that its demand will increase further in the future.
[0003]
As a light source for an optical printer, a small-sized, inexpensive and highly reliable semiconductor laser (LD) or light emitting diode (LED) is currently used. The light emission wavelength of the LED that is often used at present is 660 nm, and the light emission wavelength region of the LD is in the near infrared light region. Therefore, development of an electrophotographic photoreceptor having high sensitivity from the visible light region to the near infrared light region is desired.
[0004]
The photosensitive wavelength region of the electrophotographic photosensitive member is almost determined by the photosensitive wavelength region of the charge generating material used in the photosensitive member. Therefore, many charge generating materials such as various azo pigments, polycyclic quinone pigments, trigonal selenium and various phthalocyanine pigments have been developed. Among them, titanyl phthalocyanine (abbreviated as TiOPc) exhibits high sensitivity to light having a long wavelength of 600 to 800 nm, and therefore, a photoconductor material for an electrophotographic printer or digital copying machine whose light source is LED or LD. As extremely important and useful.
[0005]
The photosensitive wavelength region of the function-separated electrophotographic photosensitive member varies depending on the charge generating substance. Known charge generation materials having a high sensitivity around 800 nm include phthalocyanine compounds such as metal-free phthalocyanine, copper phthalocyanine, aluminum chlorophthalocyanine, chloroindium phthalocyanine, magnesium phthalocyanine, zinc phthalocyanine, titanyl phthalocyanine, and vanadyl phthalocyanine. In particular, as phthalocyanine compounds having a high sensitivity at a long wavelength, τ-type and η-type metal-free phthalocyanines disclosed in JP-A No. 58-18239, JP-A-61-109056, JP-A-62-134651, JP-A-64- No. 17066, titanyl phthalocyanine shown in JP-A-1-17259, JP-A-2-289658, 3-128973, etc., JP-A-1-268663, JP-A-3-26963, etc. There is vanadyl phthalocyanine.
[0006]
In addition, with higher performance of laser printers and copiers, electrophotographic photoreceptors are required to have higher sensitivity, and various improvements have been attempted based on the phthalocyanine compounds. For example, a photoreceptor in which a phthalocyanine compound, a perylene compound, and a hole transport material disclosed in JP-A-62-54266 are dispersed in a binder resin, a phthalocyanine compound disclosed in JP-A-63-313165 and a specific disazo. A photoreceptor having a mixture of compounds as a charge generation layer, a photoreceptor having a specific perylene compound and titanyl phthalocyanine disclosed in JP-A-3-1150 as a charge generation material, and a specific diamine derivative as a charge transport material; A photoconductor provided with a layer obtained by separately or mixing titanyl phthalocyanine and polycyclic quinone compound disclosed in JP-A-37661, and a mixture of titanyl phthalocyanine and specific phthalocyanine compound disclosed in JP-A-3-157666 as a charge generation material, Photoconductor using a specific hydrazone compound as a charge transport material, 3-1. Specific disazo compound and titanyl phthalocyanine shown in 6049 discloses a charge generating material, a photosensitive body or the like has been disclosed that certain stilbene compounds and the charge transport material.
[0007]
On the other hand, as the conditions of the electrophotographic photosensitive member repeatedly used in the Carlson process and similar processes, the electrostatic characteristics represented by sensitivity, receptive potential, potential retention, potential stability, residual potential, and spectral characteristics are excellent. Is required. In particular, for high-sensitivity photoreceptors, it has been empirically known in many photoreceptors that a decrease in chargeability and an increase in residual potential due to repeated use dominate the life characteristics of the photoreceptor. It is not an exception. Therefore, stability due to repeated use of a photoreceptor using titanyl phthalocyanine has not been sufficient yet, and the completion of the technique has been eagerly desired.
In addition, although the cause is not clear due to long-term use, there is a problem that abnormal images such as white spots and background stains occur on the image. For this reason, the material of the intermediate layer between the support and the photosensitive layer is restricted, or two laminated intermediate layers are required.
[0008]
[Problems to be solved by the invention]
An object of the present invention is to provide a novel titanyl phthalocyanine-azo pigment mixed crystal and a method for producing the same. Another object of the present invention is to provide an electrophotographic photoreceptor using the novel mixed crystal, having high sensitivity and excellent potential stability in repeated use. Still another object of the present invention is to provide an electrophotographic method using the novel mixed crystal, having high sensitivity and excellent potential stability in repeated use. Still another object of the present invention is to provide an electrophotographic apparatus using the novel mixed crystal, having high sensitivity and excellent potential stability in repeated use.
[0009]
[Means for Solving the Problems]
Examples of documents using a mixture of phthalocyanine and an azo pigment for an electrophotographic photoreceptor include, for example, JP-A-3-37666 and JP-A-7-239561. However, there has been no study on the production of a novel mixed crystal compound using titanyl phthalocyanine and an azo pigment, its production method, and the relationship with the electroconductivity of the electrophotographic photosensitive member using the mixed crystal material, that is, the electrophotographic characteristics. .
[0010]
In order to solve the above-mentioned problems, the present inventors have intensively studied a new material from the viewpoint of a mixed crystal compound, and have completed the present invention. That is, according to the present invention, first, After mixing an azo pigment dispersion / suspension containing at least one bisazo pigment represented by the following general formula (1) and amorphous titanyl phthalocyanine, which is a mixture of water, the mixture is mixed in an organic solvent. Produced by stirring, the X-ray diffraction spectrum of CuKα peaks at least at 5.8 ° ± 0.2 °, 7.5 ° ± 0.2 ° and 27.2 ° ± 0.2 ° at a Bragg angle 2θ. And no peaks at 14.2 ° ± 0.2 °, 17.8 ° ± 0.2 °, 21.3 ° ± 0.2 °, 26.5 ° ± 0.2 ° Mixed crystal composition characterized by Is provided.
[Chemical formula 2]
(Wherein R ₁ , R ₂ Represents a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a nitro group, a cyano group, a hydroxyl group, or a substituted or unsubstituted amino group, and p and q are 0-3. Represents an integer. Cp represents a coupler residue and may be the same or different. )
[0011]
Secondly, An electrophotographic photoreceptor comprising a conductive support and a photosensitive layer containing at least the mixed crystal composition described in the first aspect above. Is provided.
[0012]
Third, in an electrophotographic method in which at least charging, image exposure, development, transfer, cleaning, and static elimination are repeated on an electrophotographic photosensitive member, the electrophotographic photosensitive member is two Described in Electrophotographic photoreceptor An electrophotographic method is provided.
[0013]
Fourth, an electrophotographic apparatus comprising at least a charging means, an image exposing means, a developing means, a transferring means, a cleaning means, a charge eliminating means, and an electrophotographic photosensitive member, wherein the electrophotographic photosensitive member is the above-described first. two Described in Electrophotographic photoreceptor An electrophotographic apparatus is provided.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail.
In the present invention, the basic structure of a titanyl phthalocyanine pigment (TiOPc) used for obtaining a mixed crystal compound is represented by the following general formula (2).
[Chemical formula 5]
(Where X ₁ , X ₂ , X _Three , X _Four Each independently represents various halogen atoms, and n, m, l, and k each independently represents a number of 0 to 4)
[0015]
Various crystal forms of TiOPc are known. JP-A-59-49544, JP-A-59-166959, JP-A-61-239248, JP-A-62-67094, JP-A 63-366, JP-A 63-116158, JP-A 63-196067, and JP-A 64-17066 disclose TiOPc having different crystal forms.
[0016]
As the titanyl phthalocyanine used in the present invention, any known crystal form (including amorphous) can be used, and can be prepared by a known synthesis method or washing / purification method.
[0017]
In the present invention, a bisazo pigment represented by the following general formula (1) is used to obtain a mixed crystal compound.
[Chemical 6]
(Wherein R ₁ , R ₂ Represents a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a nitro group, a cyano group, a hydroxyl group, or a substituted or unsubstituted amino group, and p and q are 0-3. Represents an integer. Cp represents a coupler residue and may be the same or different. )
[0018]
Examples of Cp in the general formula (1) include coupler residues represented by the following general formulas (K1) to (K10).
[Chemical 7]
(R ₁ And R ₂ Represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group; ₁ , R ₂ May form a ring together with the nitrogen atom bonded to them. R _Three Represents a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a nitro group, a cyano group, a hydroxyl group, or a substituted or unsubstituted amino group, and n represents an integer of 0 to 5. )
[0019]
[Chemical 8]
(R ₁ And R ₂ Represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted styryl group, or a substituted or unsubstituted heterocyclic group; ₁ , R ₂ May form a ring together with carbon atoms bonded to them. R _Three Represents a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a nitro group, a cyano group, a hydroxyl group, or a substituted or unsubstituted amino group, and n represents an integer of 0 to 5. )
[0020]
[Chemical 9]
(R ₁ And R ₂ Represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group, and R ₁ , R ₂ May form a ring together with the nitrogen atom bonded to them. R _Three Represents a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a nitro group, a cyano group, a hydroxyl group, or a substituted or unsubstituted amino group, and R _Three May form a ring. n represents an integer of 0 to 4. )
[0021]
Embedded image
(R ₁ And R ₂ Represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted styryl group, or a substituted or unsubstituted heterocyclic group; ₁ , R ₂ May form a ring together with carbon atoms bonded to them. R _Three Represents a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a nitro group, a cyano group, a hydroxyl group, or a substituted or unsubstituted amino group, and R _Three May form a ring. n represents an integer of 0 to 4. )
[0022]
Embedded image
(R ₁ And R ₂ Represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group, and R ₁ , R ₂ May form a ring together with the nitrogen atom bonded to them. R _Three Represents a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a nitro group, a cyano group, a hydroxyl group, or a substituted or unsubstituted amino group, and n represents an integer of 0 to 6. )
[0023]
Embedded image
(R ₁ And R ₂ Represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group, and R ₁ , R ₂ May form a ring together with the nitrogen atom bonded to them. X represents a heterocyclic ring or a substituted product thereof. )
[0024]
Embedded image
(R ₁ Represents a substituted or unsubstituted alkyl group, carbamoyl group, carboxyl group, or ester thereof, Ar ₁ Represents a hydrocarbon ring group or a substituted product thereof. )
[0025]
Embedded image
(R ₁ Represents a substituted or unsubstituted hydrocarbon group. )
[0026]
Embedded image
(Y represents an aromatic hydrocarbon divalent group or a heterocyclic divalent group containing a nitrogen atom in the ring.)
[0027]
Embedded image
(R ₁ And R ₂ Represents a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a nitro group, a cyano group, a hydroxyl group, or a substituted or unsubstituted amino group, and m and n are integers of 0 to 5 Represents. )
[0028]
Next, a novel mixed crystal compound produced by using these titanyl phthalocyanines and azo pigments will be described.
The novel composition of the present invention is a composition comprising titanyl phthalocyanine and one of the bisazo pigments of the general formula (1), and the CuKα X-ray diffraction spectrum of the composition is at least at a Bragg angle 2θ. It is characterized by having peaks at 5.8 ° ± 0.2 ° and 27.2 ° ± 0.2 °. Specifically, the composition is a composition comprising titanyl phthalocyanine and one of the bisazo pigments of the general formula (1), and the CuKα X-ray diffraction spectrum of the composition is at least 5 at a Bragg angle 2θ. It is characterized by having peaks at 8 ° ± 0.2 °, 7.5 ° ± 0.2 ° and 27.2 ° ± 0.2 °. More specifically, the composition is a composition comprising titanyl phthalocyanine and one of the bisazo pigments of the general formula (1), and the CuKα X-ray diffraction spectrum of the composition has at least a Bragg angle 2θ. It is characterized by having peaks at 5.8 ° ± 0.2 ° and 27.2 ° ± 0.2 ° and no peaks at 26.5 ° ± 0.2 °. More specifically, the composition is a composition comprising titanyl phthalocyanine and one of the bisazo pigments of the general formula (1), and the CuKα X-ray diffraction spectrum of the composition has at least a Bragg angle 2θ. It has peaks at 5.8 ° ± 0.2 °, 7.5 ° ± 0.2 ° and 27.2 ° ± 0.2 °, and 14.2 ° ± 0.2 °, 17.8 ° It is characterized by having no peaks at ± 0.2 °, 21.3 ° ± 0.2 °, and 26.5 ° ± 0.2 °.
[0029]
Next, a method for producing a novel mixed crystal compound produced using these titanyl phthalocyanines and azo pigments will be described.
First, known organic solvents for dispersing / suspending azo pigments can be widely used. In particular, isopropanol, acetone, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, dioxane, ethyl cellosolve, ethyl acetate, methyl acetate, dichloromethane, dichloroethane, monochlorobenzene, cyclohexane, toluene, xylene, ligroin and the like can be preferably used. These solvents are used alone or in combination. Examples of the method for dispersing / suspending the azo pigment in an organic solvent include known methods such as ultrasonic dispersion, ball mill, attritor, sand mill, vibration mill, disk vibration mill, paint shaker, and jet mill. You may just stir both.
[0030]
The azo pigment dispersion / suspension produced in this manner is mixed with titanyl phthalocyanine. At this time, the titanyl phthalocyanine may be in any state of powder, cake, slurry, and dispersion / suspension. However, the use of the wet cake and aqueous slurry obtained in the titanyl phthalocyanine synthesis / generation process leads to simplification of the process, which is economical, and the economical use of TiOPc used in the present invention and the azo pigment of the general formula (1). The ratio of TiOPc to 1 is 0.01 to 100, preferably 0.1 to 90 for the azo pigment of the general formula (1).
When mixing the azo pigment dispersion / suspension and titanyl phthalocyanine, the latter may be added to the former, conversely, the former may be added to the latter, and the former may be added to another container. May be added simultaneously.
[0031]
After mixing the bisazo pigment of the general formula (1) and titanyl phthalocyanine as described above, the mixed solution may be stirred and mixed, and after this operation, known methods such as filtration, centrifugation, freeze-drying, drying, etc. The desired mixed crystal composition can be separated from the liquid component through the separation step.
[0032]
Hereinafter, the present invention will be described with reference to the drawings.
FIG. 1 is a schematic cross-sectional view showing an organic photoconductive layer used in the present invention. A single-layer photosensitive layer 33 mainly composed of a charge generation material and a charge transport material is provided on a conductive support 31. Yes. 2 and 3 are schematic cross-sectional views showing other examples of the structure of the organic photoconductive layer used in the present invention. The charge generation layer 35 mainly includes a charge generation material and the charge transport material as a main component. The charge transport layer 37 has a laminated structure. The organic photoconductive layer having such a structure can be used as it is as an organic photoconductor for electrophotography, and a counter electrode (not shown) is provided on the conductive support 31 to provide a photosensor, a photocell, etc. It can also be used.
[0033]
The conductive support 31 has a volume resistance of 10 ^Ten Films having conductivity of Ω · cm or less, for example, metals such as aluminum, nickel, chromium, nichrome, copper, gold, silver, platinum, metal oxides such as tin oxide, indium oxide, etc. are deposited or sputtered. Or plastic coated paper or paper, or a plate made of aluminum, aluminum alloy, nickel, stainless steel, etc., and the surface after cutting, superfinishing, polishing, etc. Treated tubes and the like can be used. Further, an endless nickel belt or an endless stainless steel belt disclosed in Japanese Patent Application Laid-Open No. 52-36016 can also be used as the conductive support 31.
[0034]
In addition, the conductive support 31 of the present invention can be used by dispersing conductive powder in an appropriate binder resin and coating the support. Examples of the conductive powder include carbon black, acetylene black, metal powder such as aluminum, nickel, iron, nichrome, copper, zinc, and silver, or metal oxide powder such as conductive tin oxide and ITO. It is done. The binder resin used at the same time is polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer. , Polyvinyl acetate, polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, acrylic resin, silicone resin, epoxy resin, Examples thereof include thermoplastic resins such as melamine resin, urethane resin, phenol resin, and alkyd resin, thermosetting resin, and photocurable resin. Such a conductive layer can be provided by dispersing and coating these conductive powder and binder resin in a suitable solvent such as tetrahydrofuran, dichloromethane, methyl ethyl ketone, and toluene.
[0035]
Furthermore, a conductive layer is provided on a suitable cylindrical substrate by a heat-shrinkable tube containing the conductive powder in a material such as polyvinyl chloride, polypropylene, polyester, polystyrene, polyvinylidene chloride, polyethylene, chlorinated rubber, and Teflon. Can be used favorably as the conductive support 31 of the present invention.
[0036]
Next, the photosensitive layer will be described. The photosensitive layer may be a single layer or a laminate, but for convenience of explanation, the case where it is composed of the charge generation layer 35 and the charge transport layer 37 will be described first.
[0037]
The charge generation layer 35 is a layer mainly composed of a mixed crystal composition composed of the above-described TiOPc as a charge generation material and the azo pigment of the general formula (1).
The charge generation layer 35 is formed by dispersing the charge generation material together with a binder resin in a suitable solvent as necessary, coating the conductive material on a conductive support, and drying.
[0038]
A well-known thing can be widely used for the non-aqueous solvent as a dispersion medium for disperse | distributing a mixed crystal composition. Specifically, isopropanol, acetone, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, dioxane, ethyl cellosolve, ethyl acetate, methyl acetate, dichloromethane, dichloroethane, monochlorobenzene, cyclohexane, toluene, xylene, ligroin and the like can be preferably used. These solvents are used alone or in combination. These solvents may be used by mixing them from the beginning, or after diluting TiOPc and / or the azo pigment of the general formula (1) using these solvents, a diluting solvent may be mixed.
[0039]
Examples of the binder resin that may be used as appropriate include polyamide, polyurethane, polyester, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, and polyacrylamide.
[0040]
The ratio (weight ratio) between the binder resin and the pigment is preferably 0/3 to 3/1, and more preferably 0/2 to 2/1. The binder resin may be added before the dispersion, or may be added after the mixed crystal composition is dispersed only with the solvent. It is also possible to add during the dispersion.
[0041]
Examples of the material of the media during wet dispersion include zirconia, glass, alumina, non-oxide, and metal.
Examples of the dispersing means for obtaining a dispersion by wet dispersion include known methods such as a ball mill, an attritor, a sand mill, a vibration mill, a disk vibration mill, a paint shaker, and a jet mill.
As a coating method of the coating solution, methods such as dip coating, spray coating, beat coating, nozzle coating, spinner coating, ring coating, and the like can be used.
[0042]
In addition to the TiOPc and the azo pigment of the general formula (1), other charge generation materials can be used in combination in the charge generation layer 35. Representative examples thereof include azo pigments, perylene pigments, and perinone. Pigments, quinacridone pigments, quinone condensed polycyclic compounds, squalic acid dyes, other phthalocyanine pigments, naphthalocyanine pigments, azulenium salt dyes, and the like.
The thickness of the charge generation layer 35 is suitably about 0.01 to 5 μm, preferably 0.1 to 2 μm.
[0043]
The charge transport layer 37 can be formed by dissolving or dispersing a charge transport material and a binder resin in a suitable solvent, and applying and drying the solution on the charge generation layer. Moreover, a plasticizer, a leveling agent, antioxidant, etc. can also be added as needed.
[0044]
Charge transport materials include hole transport materials and electron transport materials. Examples of the electron transport material include chloranil, bromoanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone and 2,4. , 5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1,2-b] thiophen-4-one, 1,3,7-tri Examples thereof include electron-accepting substances such as nitrodibenzothiophene-5,5-dioxide and benzoquinone derivatives.
[0045]
Examples of hole transport materials include poly-N-vinylcarbazole and derivatives thereof, poly-γ-galvazolylethyl glutamate and derivatives thereof, pyrene-formaldehyde condensates and derivatives thereof, polyvinylpyrene, polyvinylphenanthrene, polysilane, oxazole derivatives, Oxadiazole derivatives, imidazole derivatives, monoarylamine derivatives, diarylamine derivatives, triarylamine derivatives, stilbene derivatives, α-phenylstilbene derivatives, benzidine derivatives, diarylmethane derivatives, triarylmethane derivatives, 9-styrylanthracene derivatives, pyrazolines Derivatives, divinylbenzene derivatives, hydrazine derivatives, indene derivatives, butadiene derivatives, pyrene derivatives, etc., bis-stilbene derivatives, enamine derivatives, etc. Knowledge materials are mentioned. These charge transport materials may be used alone or in combination of two or more.
[0046]
The binder resin is polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, poly Vinylidene chloride, polyarate, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin And thermoplastic or thermosetting resins such as alkyd resins.
[0047]
The amount of the charge transport material is appropriately 20 to 300 parts by weight, preferably 40 to 150 parts by weight, based on 100 parts by weight of the binder resin. The thickness of the charge transport layer is preferably about 5 to 100 μm. As the solvent used here, tetrahydrofuran, dioxane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, methyl ethyl ketone, acetone and the like are used.
[0048]
In the present invention, a plasticizer or a leveling agent may be added to the charge transport layer 37. As the plasticizer, those used as plasticizers for general resins such as dibutyl phthalate and dioctyl phthalate can be used as they are, and the amount used is suitably about 0 to 30% by weight with respect to the binder resin. As the leveling agent, silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, and polymers or oligomers having a perfluoroalkyl group in the side chain are used, and the amount used is 0 to 1 weight relative to the binder resin. % Is appropriate.
[0049]
Next, the case where the photosensitive layer has a single layer structure 33 will be described. A photoreceptor in which the above-described TiOPc and the azo pigment of the general formula (1) are dispersed in a binder resin can be used. The single-layer photosensitive layer can be formed by dissolving or dispersing a charge generating substance, a charge transporting substance and a binder resin in a suitable solvent, and applying and drying them. Further, the photosensitive layer may be a function separation type to which the above-described charge transport material is added, and can be used satisfactorily. Moreover, a plasticizer, a leveling agent, antioxidant, etc. can also be added as needed.
[0050]
As the binder resin, the binder resin previously mentioned in the charge transport layer 37 may be used as it is, or the binder resin mentioned in the charge generation layer 35 may be mixed and used. The amount of the charge generation material with respect to 100 parts by weight of the binder resin is preferably 5 to 40 parts by weight, and the amount of the charge transport material is preferably 0 to 190 parts by weight, and more preferably 50 to 150 parts by weight. A single-layer photosensitive layer is formed by dip coating or spraying with a coating solution dispersed with a disperser using a solvent such as tetrahydrofuran, dioxane, dichloroethane, or cyclohexane together with a charge transport material, if necessary, with a charge generating material and a binder resin. It can be formed by coating with a coat or bead coat. The thickness of the single photosensitive layer is suitably about 5 to 100 μm.
[0051]
In the electrophotographic photosensitive member of the present invention, an undercoat layer can be provided between the conductive support 31 and the photosensitive layer. In general, the undercoat layer is mainly composed of a resin. However, considering that the photosensitive layer is coated with a solvent on these resins, the resin may be a resin having high solvent resistance with respect to a general organic solvent. desirable. Examples of such resins include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon, polyurethane, melamine resin, phenol resin, alkyd-melamine resin, and epoxy. Examples thereof include a curable resin that forms a three-dimensional network structure such as a resin. Further, a metal oxide fine powder pigment exemplified by titanium oxide, silica, alumina, zirconium oxide, tin oxide, indium oxide and the like may be added to the undercoat layer in order to prevent moire and reduce residual potential.
[0052]
These undercoat layers can be formed using an appropriate solvent and coating method as in the above-mentioned photosensitive layer. Furthermore, a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like can be used as the undercoat layer of the present invention. In addition, the undercoat layer of the present invention includes A1. ₂ O _Three Anodic oxidation, organic materials such as polyparaxylylene (parylene), and SiO ₂ , SnO ₂ , TiO ₂ , ITO, CeO ₂ A material provided with an inorganic material such as a vacuum thin film can be used well. In addition, known ones can be used. The thickness of the undercoat layer is suitably from 0 to 5 μm.
[0053]
In the electrophotographic photoreceptor of the present invention, a protective layer may be provided on the photosensitive layer for the purpose of protecting the photosensitive layer. Materials used for the protective layer include ABS resin, ACS resin, olefin-vinyl monomer copolymer, chlorinated polyether, allyl resin, phenol resin, polyacetal, polyamide, polyamideimide, polyacrylate, polyallylsulfone, polybutylene. , Polybutylene terephthalate, polycarbonate, polyethersulfone, polyethylene, polyethylene terephthalate, polyimide, acrylic resin, polymethylpentene, polypropylene, polyphenylene oxide, polysulfone, polystyrene, AS resin, butadiene-styrene copolymer, polyurethane, polyvinyl chloride, Examples of the resin include polyvinylidene chloride and epoxy resin. In addition to the protective layer, fluorine resins such as polytetrafluoroethylene, silicone resins, and those resins dispersed with inorganic materials such as titanium oxide, tin oxide, potassium titanate, etc. for the purpose of improving wear resistance, etc. Can be added. As a method for forming the protective layer, a normal coating method is employed. In addition, about 0.1-10 micrometers is suitable for the thickness of a protective layer. In addition to the above, a known material such as a-C or a-SiC formed by a vacuum thin film forming method can be used as the protective layer.
[0054]
In the present invention, an intermediate layer can be provided between the photosensitive layer and the protective layer. In the intermediate layer, a binder resin is generally used as a main component. Examples of these resins include polyamide, alcohol-soluble nylon, water-soluble polyvinyl butyral, polyvinyl butyral, and polyvinyl alcohol. As a method for forming the intermediate layer, a normal coating method is employed as described above. The thickness of the intermediate layer is suitably about 0.05 to 2 μm.
[0055]
Next, the electrophotographic method and the electrophotographic apparatus of the present invention will be described in detail with reference to the drawings.
[0056]
FIG. 4 is a schematic diagram for explaining the electrophotographic process and the electrophotographic apparatus of the present invention, and the following modifications also belong to the category of the present invention.
[0057]
In FIG. 4, this electrophotographic apparatus is close to the upper surface of the drum-shaped photosensitive member 1 and counterclockwise along the circumference, in a static elimination exposure unit 2, a charging charger 3, an eraser 4, an image exposure unit 5, A developing unit 6, a pre-transfer charger 7, a transfer charger 10, a separation charger 11, a separation claw 12, a pre-cleaning charger 13, a fur brush 14, and a cleaning blade 15 are sequentially provided. Further, a registration roller 8 for feeding the transfer paper 9 between the photosensitive member 1 and the transfer charger 10 and the separation charger 11 is provided. The photoreceptor 1 is composed of a drum-like conductive support and a photosensitive layer in close contact with the upper surface thereof, and rotates counterclockwise.
[0058]
In the electrophotographic method using the above-described electrophotographic apparatus, the photoreceptor 1 rotates counterclockwise, is negatively (or positively) charged by the charging charger 3, and is electrostatically charged by the image exposure unit 5 by exposure. A latent image is formed on the photoreceptor 1.
As the transfer means, the above charger can be generally used. However, as shown in the figure, a combination of a transfer charger and a separation charger is effective.
[0059]
In addition, light sources such as the image exposure unit 5 and the charge removal lamp 2 emit light such as a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED), a semiconductor laser (LD), and an electroluminescence (EL). Things can be used. Various types of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range. Such a light source or the like irradiates the photosensitive member with light by providing a transfer process, a static elimination process, a cleaning process, or a pre-exposure process using light irradiation in addition to the process shown in FIG.
[0060]
In the developing unit 6, the electrostatic latent image is developed by attaching toner on the photoreceptor 1, the charged state of the toner image is adjusted by the pre-transfer charger 7, and then the toner image is transferred onto the transfer paper 9 by the transfer charger 10. The transfer and separation charger 11 eliminates the electrostatic adhesion between the photoreceptor 1 and the transfer paper 9, and the separation paper 12 is separated from the photoreceptor 1 by the separation claw 12. After the transfer paper 9 is separated, the surface of the photoreceptor 1 is cleaned by the pre-cleaning charger 13, the fur brush 14 and the cleaning blade 15. This cleaning can also be performed by removing the remaining toner with the cleaning blade 15 alone.
[0061]
When the electrophotographic photosensitive member is positively (negatively) charged and image exposure is performed, a positive (negative) electrostatic latent image is formed on the surface of the photosensitive member.
If this is developed with negative (positive) toner, a positive image can be obtained, and if developed with positive (negative) toner, a negative image can be obtained.
A known method is applied to the developing unit, and a known method is also used for the charge eliminating unit.
[0062]
In this example, the conductive support is shown as a drum, but a sheet or endless belt can be used. As the pre-cleaning charger, known charging means such as a corotron, a scorotron, a solid state charger, a charging roller and the like can be used. In addition, although the above charging means can be used for the transfer charger and the separation charger, a charger in which the transfer charger and the separation charger are integrated as shown in FIG. 4 is efficient and preferable. As the cleaning member, a known member such as a blade, a fur brush, a mag fur brush or the like can be used.
[0063]
FIG. 5 shows a schematic diagram illustrating another example of the electrophotographic process of the present invention. In this example, the belt-shaped photosensitive member 21 has a photosensitive layer containing a mixed crystal composition, and is driven by a driving roller 22a or 22b, charged by a charging charger 23, image exposure by an image exposure source 24, A series of image formation including development (not shown), transfer by the transfer charger 25, pre-cleaning exposure by the pre-cleaning exposure unit 26, cleaning by the cleaning brush 27, and static elimination by the static elimination light source 28 are repeatedly performed. In this case, the pre-cleaning exposure part is exposed from the conductive support side of the photosensitive member 21. Of course, in this case, the conductive support is translucent.
[0064]
The above illustrated electrophotographic process is illustrative of an embodiment of the present invention, and of course other embodiments are possible. For example, in FIG. 5, the pre-cleaning exposure is performed from the support side, but this may be performed from the photosensitive layer side, or image exposure and discharge exposure may be performed from the support side.
[0065]
On the other hand, in the light irradiation process, image exposure, pre-cleaning exposure, and static elimination exposure are illustrated, but other pre-exposure exposure, pre-exposure of image exposure, and other known light irradiation processes are provided to light the photosensitive member. Irradiation can also be performed.
[0066]
The image forming means as described above may be fixedly incorporated in a copying apparatus, a facsimile, or a printer, but may be incorporated in these apparatuses in the form of a process cartridge. A process cartridge is a single device (part) that contains a photosensitive member and includes a charging unit, an exposure unit, a developing unit, a transfer unit, a cleaning unit, and a charge eliminating unit. There are many shapes and the like of the process cartridge, but a general example is shown in FIG. The process cartridge shown in FIG. 6 has a compact structure including a charging charger 17, a cleaning brush 18, an image exposure unit 19, a developing roller 20 and the like disposed around the photoconductor 16.
[0067]
【Example】
EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated, this invention is not restrict | limited by these Examples. All parts are parts by weight.
[0068]
First, a specific synthesis example of a titanyl phthalocyanine pigment used in Examples will be described.
Synthesis example 1
52.5 parts of phthalodinitrile and 400 parts of 1-chloronaphthalene are stirred and mixed, and 19 parts of titanium tetrachloride are added dropwise under a nitrogen stream. After completion of the dropwise addition, the temperature was gradually raised to 200 ° C., and the reaction was carried out by stirring for 5 hours while maintaining the reaction temperature between 190 ° C. and 210 ° C. After completion of the reaction, the mixture was allowed to cool and filtered when hot at 130 ° C., then washed with 1-chloronaphthalene until the powder turned blue, then washed several times with methanol, and further with hot water at 80 ° C. After washing twice, it was dried to obtain 42.2 parts of crude titanyl phthalocyanine pigment. Six parts of the obtained crude titanyl phthalocyanine pigment washed with hot water were stirred and dissolved in 100 g of 96% sulfuric acid at 3 to 5 ° C. and filtered. The obtained sulfuric acid solution was added dropwise with stirring in 3.5 liters of ice water, the precipitated crystals were filtered, and then washed with water until the washing solution became neutral to obtain a titanyl phthalocyanine pigment wet cake (solid content concentration 10 weight%).
The wet cake was vacuum-dried and the X-ray diffraction spectrum described below was measured, and as a result, it was found to be amorphous (amorphous).
[0069]
Example 1
3 parts of the azo pigment of the general formula (1) represented by the following structural formula (A) was put into 200 parts of 2-butanone, applied to an ultrasonic disperser, dispersed for 5 hours, and then well stirred with a stirrer. Into this, 50 parts of a titanyl phthalocyanine pigment wet cake (solid content concentration 10% by weight) produced in Synthesis Example 1 was added and stirred well for 8 hours. Next, 800 parts of methanol was added and stirred for 2 hours. This liquid substance was filtered using a 1 μm fluoropore filter, and the separated solid substance was dried at 70 ° C. for 20 hours. A solid was obtained.
[0070]
Embedded image
[0071]
A ball mill pot with an internal volume of 0.3 liters was filled with zirconia balls, and the titanyl phthalocyanine-azo pigment obtained above and each of the following materials were added, followed by rolling and dispersing at room temperature for 48 hours to obtain a dispersion. .
2 parts of TiOPc / azo pigment powder
Polyvinyl butyral 1 part
Tetrahydrofuran 100 parts
[0072]
Example 2
A dispersion was obtained in the same manner as in Example 1 except that a zirconia ball was filled in a 0.3 liter ball mill pot and cyclohexanone was used instead of tetrahydrofuran used in Example 1.
[0073]
Comparative Example 1
To 200 parts of 2-butanone, 50 parts of a titanyl phthalocyanine face wet cake (solid content concentration 10% by weight) prepared in Synthesis Example 1 was added and stirred well for 8 hours. Next, 800 parts of methanol was added and stirred for 2 hours. This liquid was filtered using a 1 μm fluoropore filter, and the separated solid was dried at 70 ° C. for 20 hours to obtain 4.9 parts of a dried solid.
[0074]
A ball mill pot with an internal volume of 0.3 liters was filled with zirconia balls, and after the titanyl phthalocyanine pigment powder obtained above and each of the following materials were added, it was tumbled and dispersed at room temperature for 48 hours to obtain a dispersion.
2 parts of TiOPc pigment powder
Polyvinyl butyral 1 part
Tetrahydrofuran 100 parts
[0075]
Comparative Example 2
A dispersion was obtained in the same manner as in Comparative Example 1 except that a zirconia ball was filled in a 0.3 liter ball mill pot and cyclohexanone was used instead of tetrahydrofuran used in Comparative Example 1.
[0076]
Comparative Example 3
A ball mill pot with an internal volume of 0.3 liters was filled with zirconia balls, and the following materials were charged, followed by rolling and dispersing at room temperature for 48 hours to obtain a dispersion.
2 parts of the azo pigment of the general formula (1) used in Example 1
Polyvinyl butyral 1 part
Tetrahydrofuran 100 parts
[0077]
Example 3
4 parts of the azo pigment of the general formula (1) represented by the following structural formula (B) was put into 200 parts of 2-butanone, applied to an ultrasonic disperser, dispersed for 5 hours, and then thoroughly stirred with a stirrer. Into this, 40 parts of a titanyl phthalocyanine pigment wet cake (solid content concentration 10% by weight) produced in Synthesis Example 1 was added and stirred well for 8 hours. Next, 800 parts of methanol was added and stirred for 2 hours. This liquid substance was filtered using a 1 μm fluoropore filter, and the separated solid substance was dried at 70 ° C. for 20 hours. A solid was obtained.
[0078]
Embedded image
[0079]
A ball mill pot with an internal volume of 0.3 liters was filled with zirconia pole, the titanyl phthalocyanine-azo pigment obtained above and each of the following materials were added, and then tumbled and dispersed at room temperature for 48 hours to obtain a dispersion. .
2 parts of TiOPc / azo pigment powder
Polyvinyl butyral 1 part
Tetrahydrofuran 100 parts
[0080]
Example 4
A dispersion was obtained in the same manner as in Example 3, except that zirconia balls were filled in a 0.3 liter ball mill pot and cyclohexanone was used instead of tetrahydrofuran used in Example 3.
[0081]
Part of each of the dispersions of Examples 1 to 4 and Comparative Examples 1 to 3 prepared as described above was dried at room temperature and in the air to obtain pigment powder. About the obtained pigment powder, the X-ray powder diffraction spectrum was measured on the conditions shown below. FIGS. 7 to 11 show pigment X-ray diffraction spectra of the dispersions of Example 1, Example 2, and Comparative Examples 1 to 3, respectively.
X-ray tube Cu
Voltage 40kV
Current 20mA
Scanning speed 1 ° / min
Scanning range 3 ° ~ 40 °
Time constant 2 seconds
[0082]
When Example 1 and Comparative Example 1 and Example 2 and Comparative Example 2 are respectively compared, it can be seen that peaks are observed at different diffraction angles and the crystal types are different. Furthermore, when Example 1 and Example 2 are compared with Comparative Example 3, Examples 1 and 2 observed 17.8 ° ± 0.2 °, 21.3 ° ± 0.2 ° observed in Comparative Example 3, It can be seen that the peak at 26.5 ° ± 0.2 ° has disappeared. On the other hand, Examples 1 and 2 have peaks at 5.8 ± 0.2 ° and 27.2 ° ± 0.2 ° which are not observed in Comparative Examples 1 and 2. From the above results, it is clear that the titanyl phthalocyanine-azo pigments of Examples 1 and 2 form a mixed crystal composition.
Moreover, since the measurement result of Example 3 shows the same diffraction peak angle as Example 1 and the measurement result of Example 4 shows Example 2, the titanyl phthalocyanine-azo pigment of Examples 3 and 4 is also the same. It can be seen that a mixed crystal composition is formed.
[0083]
Next, an undercoat layer coating solution having the following composition on the aluminum cylinder, the pigment dispersions of the above Examples 1 to 4 and Comparative Examples 1 to 3, and the charge transport coating solution having the following composition were sequentially applied. A dried photoreceptor was provided with an undercoat layer having a dry film thickness of 2.5 μm, a charge generation layer having a thickness of 0.3 μm, and a charge transport layer having a thickness of 22 μm. These are referred to as the photoreceptors of Examples 1 to 4 and Comparative Examples 1 to 3 described above.
[0084]
<Undercoat layer coating solution>
Titanium dioxide powder 15 parts
Polyvinyl butyral 2 parts
Epoxy resin 2 parts
2-butanone 130 parts
<Charge transport layer coating solution>
10 parts of polycarbonate
6 parts of charge transport material of the following structural formula
Embedded image
75 parts of methylene chloride
[0085]
Each of the above photoreceptors was subjected to the following measurement using an evaluation apparatus disclosed in JP-A-60-1000016. Electric potential Vm [V] after 20 seconds charging with corona discharge voltage -5.7 [kV], potential Vo [V] after dark decay 20 seconds, 500 nm and 780 nm monochromatic light with an intensity of 0.5 μw / cm ² Exposure dose E required to attenuate the potential Vo to 1/5. _1/5 [Lx · s] was measured. The potential holding ratio is defined as follows.
Potential holding ratio = Vo / Vm
Further, each of the above electrophotographic photosensitive members is mounted on the electrophotographic process shown in FIG. 4 (however, the image exposure light source is an LD having a light emission at 780 nm), and 5,000 sheets are continuously printed. The printed image was evaluated.
[0086]
The results are shown in Table 1. As is apparent from the results in Table 1, the electrophotographic photosensitive member of the present invention maintains good image quality even with a large number of printings.
[0087]
[Table 1]
[0088]
【The invention's effect】
According to the present invention, a novel organic pigment mixed crystal comprising titanyl phthalocyanine and an azo pigment having a specific chemical structure and a method for producing the same are provided. Further, according to the present invention, by using the organic pigment mixed crystal, high sensitivity is exhibited from the visible region to the near infrared region, and in particular, the sensitivity in the near infrared region is higher than that in the case where no mixed crystal is formed. The illustrated photoconductor, especially an electrophotographic photoreceptor, can be formed. Furthermore, according to the present invention, an electrophotographic method and an electrophotographic apparatus including an electrophotographic photosensitive member having a photoconductive layer made of titanyl phthalocyanine and an azo pigment having a specific chemical structure are provided. A quality printing system is provided.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of an electrophotographic photosensitive member used in the present invention.
FIG. 2 is a schematic cross-sectional view of another electrophotographic photosensitive member used in the present invention.
FIG. 3 is a schematic cross-sectional view of still another electrophotographic photosensitive member used in the present invention.
FIG. 4 is a schematic view for explaining an electrophotographic apparatus of the present invention.
FIG. 5 is a schematic view for explaining an electrophotographic apparatus of the present invention.
FIG. 6 is a schematic view for explaining a representative electrophotographic apparatus of the present invention.
7 is a pigment X-ray diffraction spectrum diagram of the dispersion liquid obtained in Example 1. FIG.
8 is a pigment X-ray diffraction spectrum diagram of the dispersion liquid obtained in Example 2. FIG.
9 is a pigment X-ray diffraction spectrum diagram of the dispersion obtained in Comparative Example 1. FIG.
10 is a pigment X-ray diffraction spectrum diagram of the dispersion liquid obtained in Comparative Example 2. FIG.
11 is a pigment X-ray diffraction spectrum diagram of the dispersion liquid obtained in Comparative Example 3. FIG.

Claims (4)

After mixing an azo pigment dispersion / suspension containing at least one bisazo pigment represented by the following general formula (1) and amorphous titanyl phthalocyanine, which is a mixture of water, the mixture is mixed in an organic solvent. Produced by stirring, the X-ray diffraction spectrum of CuKα peaks at least at 5.8 ° ± 0.2 °, 7.5 ° ± 0.2 ° and 27.2 ° ± 0.2 ° at a Bragg angle 2θ. And no peaks at 14.2 ° ± 0.2 °, 17.8 ° ± 0.2 °, 21.3 ° ± 0.2 °, 26.5 ° ± 0.2 ° A mixed crystal composition characterized by the above.
(Wherein R ₁ and R ₂ represent a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a nitro group, a cyano group, a hydroxyl group, or a substituted or unsubstituted amino group, p and q represent an integer of 0 to 3. Cp represents a coupler residue and may be the same or different. An electrophotographic photosensitive member comprising a conductive support and a photosensitive layer containing at least the mixed crystal composition according to claim 1. The electrophotographic photosensitive member, at least charging, image exposure, development, transfer, cleaning, in an electrophotographic method repeating the neutralization, and wherein the electrophotographic photoreceptor is an electrophotographic photosensitive member according to claim 2 Electrophotographic method. At least charging means, image exposure means, developing means, transfer means, cleaning means, an electrophotographic apparatus comprising comprises a discharging means and an electrophotographic photosensitive member, the electrophotographic of the electrophotographic photosensitive member according to claim 2 An electrophotographic apparatus which is a photoconductor .