JP2000129155A - Crystal type oxotitanyl phthalocyanine and electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a crystal type oxotitanyl phthalocyanine having high photosensitivity characteristics sufficient for higher performances of an optical printer, a digital copier, etc., using a semiconductor laser or a light-emitting diode(LED) array as a light source and providing an electrophotographic photoreceptor having high durability and to provide the electrophotographic photoreceptor using the crystal type oxotitanyl phthalocyanine. SOLUTION: This phthalocyanine is a crystal type oxotitanyl phthalocyanine having main peaks at 7.3 deg., 9.4 deg., 9.6 deg., 11.6 deg., 13.3 deg., 17.9 deg., 24.1 deg. and 27.2 deg. expressed in terms of Bragg angles (2θ±0.2 deg.) in an X-ray diffraction spectrum. The overlapped peak flux of 9.4 deg. and 9.6 deg. manifests the maximum peak and the peak at 27.2 deg. has the second maximum peak. The electrophotographic photoreceptor is obtained by using the crystal oxotitanyl phthalocyanine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a specific crystalline oxotitanyl phthalocyanine and an electrophotographic photoreceptor using a composition containing the crystalline oxotitanyl phthalocyanine for a charge generating layer.

[0002]

2. Description of the Related Art F. In recent years, the electrophotographic technology according to Carlson's invention has been widely used not only in the field of copiers but also in the fields of various printers and facsimile machines because of the ability to obtain images with immediacy, high quality and high storability. The technical field is expanding greatly.

[0003] This electrophotographic process basically comprises the steps of uniformly charging a photoreceptor, forming a latent image by exposing the image, developing the latent image with toner, and transferring the toner image to paper (in the case of passing through a transfer member in the middle). And an image forming process by fixing.

[0004] As a photoreceptor at the core of electrophotographic technology,
Electrophotographic photoconductors currently in practical use are classified into inorganic photoconductors using inorganic materials and organic photoconductors using organic materials. Conventionally, inorganic photoconductors have been used as electrophotographic photoconductors in terms of sensitivity and durability.

Representative examples of inorganic photoreceptors include selenium-based ones made of amorphous selenium (a-Se) or amorphous selenium arsenide (a-AsSe), dye-sensitized zinc oxide (ZnO) or cadmium sulfide (C
dS) dispersed in a binder resin, and amorphous silicon (a-Si). However, among the inorganic photoreceptors, selenium-based photoreceptors and photoreceptors using CdS have problems in heat resistance and storage stability, and furthermore have toxicity, so that disposal thereof becomes a problem.
Causes pollution. ZnO resin-dispersed photoconductors are hardly used at present because they have low sensitivity and low durability. The a-Si photoreceptor, which is attracting attention as a non-polluting inorganic photoreceptor, has advantages such as high sensitivity and high durability, but has disadvantages such as image defects caused by a manufacturing process using a plasma CVD method. There is a problem that costs are increased due to low productivity.

On the other hand, since there are many kinds of organic materials themselves, an organic material itself can be produced without preservation stability and toxicity by appropriately selecting the organic materials, and a thin film can be easily formed by coating, and the cost is low. Various investigations have been made because they can be manufactured by using the method described above. In recent years, sensitivity and durability have been sharply improved, and especially in bisazo compounds,
Practical use has been made, and at present, an organic material is used as an electrophotographic photosensitive member except for a special case.

In recent years, laser beam printers that use laser light as a light source in place of conventional white light and have the advantages of high speed, high image quality, and low impact have become widespread.
Therefore, development of a photoreceptor capable of meeting the demand is desired. In particular, among laser beams, a small and highly reliable semiconductor laser is used as a light source, and since the wavelength of the light source is around 800 nm, a photoreceptor that is highly sensitive to long wavelength light around 800 nm is strongly used. Is desired.

[0008] However, known bisazo compounds which have been put into practical use conventionally have good sensitivity in a short wavelength or middle wavelength range, but have relatively low sensitivity in a long wavelength range. Was difficult to put into practical use. In addition, methine squaric acid dyes as organic materials with relatively good sensitivity in the long wavelength region,
Indoline-based dyes, cyanine-based dyes, pyrylium-based dyes, and the like are known, but all of them lack practical stability (repeating characteristics) and have been difficult to put into practical use.

On the other hand, phthalocyanine-based compounds are also known to have good sensitivity in the long wavelength region, and are relatively widely studied in recent years because they have relatively better stability than the above-mentioned organic materials. It is known that phthalocyanines not only have different sensitivity peaks and physical properties depending on the presence or absence or type of a central metal, but also have significantly different physical properties depending on the crystal type. (See Manabu Sawada: Dyes and Pharmaceuticals Vol. 24, No. 6, p. 122 (1979)) Therefore, research on photoreceptors is being carried out including the study of crystal types. For example, as an electrophotographic photoreceptor, a photoreceptor using a metal-free phthalocyanine (for example, JP-A-60-86551) and a photoreceptor using an aluminum-containing phthalocyanine (for example, JP-A-63-133462) Gazette),
In addition, titanium as a central metal (for example,
9-49544), many central metals such as indium and gallium are known and most select a particular crystal form.

In recent years, only oxotitanyl phthalocyanine, which has been energetically studied as a phthalocyanine having high sensitivity characteristics, is disclosed in the Journal of the Electrophotographic Society, Vol. 32, No. 3,
Pp. 289, the crystal is classified into a number of crystal types based on the difference in the diffraction angle of the X-ray diffraction spectrum. Specifically, a characteristic crystal is described in JP-A-61-217050.
JP-A-61-239248, α-type, JP-A-62-67094-A, and JP-A-63-3.
No. 66 and JP-A-63-198067 disclose C.
Mold, JP-A-63-20365, JP-A-2-825
No. 6, JP-A-1-17066, JP-A-7-2
JP-A-71073 discloses a Y-type, JP-A-3-54265 discloses an M-type, and JP-A-3-54264 discloses an M-α.
The type I crystal is described in Japanese Patent Application Laid-Open No. 3-128973. Further, Japanese Patent Application Laid-Open No. Sho 62-67094 describes type I and II crystals.

By the way, crystals of oxotitanyl phthalocyanine whose lattice constants are known from the structural analysis are C-type, Phase I-type and Phase II-type. Phase II type is triclinic, Phase I type,
Form C belongs to the monoclinic system. When the crystal forms described in the above patent specification are analyzed from these known crystal lattice constants, type A and type I belong to Phase I type, α type and B type belong to Phase II type, and M type Belongs to the C type. Do the same with J. of Imaging Science and Technolog
y Vol. 37, No. 6, 1993, pp. 605-609.

[0012]

However, phthalocyanine-based compounds, particularly oxotitanyl phthalocyanine, are also preferred as a charge generation material, and the photosensitivity characteristics,
There is still no sufficient property in terms of repeated use characteristics and solvent stability.

Accordingly, an object of the present invention is to provide a novel crystalline oxotitanyl phthalocyanine having excellent photosensitivity characteristics, repeated use characteristics and solvent stability, and an electrophotographic photoreceptor using the same.

[0014]

The crystalline oxotitanyl phthalocyanine of the present invention has a Bragg angle (2θ ± 0.2 °) of 7.3 ° or 9.4 in the X-ray diffraction spectrum.
゜, 9.6 ゜, 11.6 ゜, 13.3 ゜, 17.9 ゜,
A crystalline oxotitanyl phthalocyanine having a main peak at 24.1 ° and 27.2 °, and an overlapping peak bundle of 9.4 ° and 9.6 ° at its Bragg angle (2θ ± 0.2 °). It is the maximum peak, and the peak at 27.2 ° is the second maximum peak.

The crystalline oxotitanyl phthalocyanine of the present invention is characterized in that the peak intensity at 27.2 ° is not more than 80% of the peak intensity of the overlapping peak bundle of 9.4 ° and 9.6 °. I do.

Further, in the X-ray diffraction spectrum,
The Bragg angle (2θ ± 0.2 °) from 14.1 ° to 1
At 4.9 °, a trapezoidal peak bundle is shown.

Further, the electrophotographic photoreceptor according to the present invention has a Bragg angle (2θ) in the X-ray diffraction spectrum.
At ± 0.2 °) and 9.0 °, the 9.4 ° and 9.
It is characterized by having a shoulder peak of about half the intensity of the 6 ° overlapping peak bundle.

Further, the electrophotographic photoreceptor of the present invention is characterized in that the crystalline oxotitanyl phthalocyanine according to any one of claims 1 to 4 is used as a charge generating material.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The basic structure of the oxotitanyl phthalocyanine of the present invention is
The following general formula [1]

[0020]

Embedded image

(Wherein X represents a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group, and k, l,
m and n represent an integer of 0 to 4. ).

The method for synthesizing oxotitanyl phthalocyanine is described in Moser and Thomas, "Phthalocyanine Compounds".
(MOSER and Thomas. "Phthalocianine Compounds").
For example, dichlorotitanium phthalocyanine can be obtained in a high yield by a method in which o-phthalonitrile and titanium tetrachloride are heated and melted or heated in the presence of an organic solvent such as α-chloronaphthalene. Further, oxotitanyl phthalocyanine is obtained by hydrolyzing the dichlorotitanium phthalocyanine with a base or water. Alternatively, 1,3-diiminoisoindoline and tetrabutoxytitanium can be synthesized by a method of heating with an organic solvent such as N-methylpyrrolidone. The obtained oxotitanyl phthalocyanine may contain a phthalocyanine derivative in which a hydrogen atom of a benzene ring is substituted with a substituent such as chlorine, fluorine, nitro, cyano or sulfone.

The oxotitanyl phthalocyanine composition is treated with a water-immiscible organic solvent such as dichloroethane in the presence of water to obtain the crystalline form of the present invention.

A method for treating oxotitanyl phthalocyanine with a water-immiscible organic solvent in the presence of water includes:
A method in which oxotitanyl phthalocyanine is swollen with water and treated with an organic solvent, or without performing the swelling treatment, water is added to the organic solvent, and a method in which oxotitanyl phthalocyanine powder is poured thereinto, and the like. However, the present invention is not limited to this.

As a method of swelling oxotitanyl phthalocyanine with water, for example, a method of dissolving oxotitanyl phthalocyanine in sulfuric acid and precipitating it in water to form a wet paste, or a homomixer, paint mixer, ball mill, or sand mill And the like, using an agitation / dispersion device such as swelling oxotitanyl phthalocyanine with water to form a wet paste. However, the method is not limited to these methods.

The oxotitanyl phthalocyanine composition obtained by hydrolysis is stirred for a sufficient time in a solution or a solution in which a binder resin is dissolved, or milled with a mechanical strain to obtain the present invention. Is obtained.

As a device used for this treatment, a homomixer, a paint mixer, a disperser, an agitator, a ball mill, a sand mill, an attritor, an ultrasonic dispersing device, etc. can be used in addition to a general stirring device. . After the treatment, the solution may be filtered, washed and isolated using methanol, ethanol, water, or the like, or may be used as it is as a coating liquid by adding a binder resin after the treatment. Further, a binder resin is added in advance at the time of processing, and can be used as it is as a coating liquid.

It should be noted that the phthalocyanine composition of the present invention is not limited to those produced by the above-mentioned production method, but includes any production method as long as it shows the specific peak of the present invention. Things.

The oxotitanyl phthalocyanine thus obtained exhibits excellent properties as a charge generating material for an electrophotographic photosensitive member. In the present invention, other charge generating materials may be used in addition to oxotitanyl phthalocyanine. Examples of such a charge generating material include an α-form different in crystal form from the oxotitanyl phthalocyanine of the present invention,
β-type, Y-type, amorphous oxotitanyl phthalocyanine, or other phthalocyanines, and further, azo pigments, anthraquinone pigments, perylene pigments, polycyclic quinone pigments, squarium pigments, and the like.

The constitution of the electrophotographic photosensitive member of the present invention includes:
As shown in FIG. 1, a photosensitive layer 4 is laminated on a conductive support 1, and the photosensitive layer 4 is composed of two layers, a charge generation layer 5 containing a charge generation substance 2 and a charge transport layer 6 containing a charge transport substance 3. The structure may be either a function-separated type photoreceptor or a single-layer type photosensitive layer 4 'in which the charge generating substance 5 is dispersed in the charge transporting layer 6 containing the charge transporting substance 3 as shown in FIG. As shown in FIG. 4, it is preferable in terms of manufacturing to provide a known intermediate layer 7 which is usually used between the conductive support 1 and the photosensitive layer 4. The dispersion for forming a charge generation layer containing crystalline oxotitanyl phthalocyanine as a main component is easily affected by the heat capacity of the support used, because the latent heat of evaporation of the dispersion solvent is used when the photosensitive layer is prepared by the dip coating method. By using the intermediate layer, the influence is reduced.

As the conductive support used in the present invention, those having a substrate itself having conductivity, for example, aluminum, aluminum alloy, copper, zinc, stainless steel, nickel, titanium and the like can be used. It is possible to use plastic or paper on which gold, silver, copper, zinc, nickel, titanium, indium oxide, tin oxide, or the like is deposited, plastic or paper containing conductive particles, plastic containing a conductive polymer, or the like. As the shape thereof, a drum shape, a sheet shape, a seamless belt shape and the like can be used.

In the case of a function-separated type photoreceptor, the oxotitanyl phthalocyanine of the present invention is used as the charge generation material in the charge generation layer, and may contain other charge generation materials described above.

The charge generating layer may be formed by a vacuum deposition method, a vapor deposition method such as sputtering or CVD, or by adding a binder resin and a solvent to oxotitanyl phthalocyanine as a charge generating material, if necessary, using a ball mill, sand grinder, or the like. Use a coating liquid obtained by grinding and dispersing with a paint shaker, ultrasonic disperser, etc., for a sheet, a baker applicator, bar coater, casting, spin coating, etc., for a drum, a spray method, a vertical ring It is produced by a method and a dip coating method.

As the binder resin, stability of the coating solution,
From the stability of the crystal type, a butyralized polymer or a polymer having a hydroxyl group is preferable, but polyester resin, polyvinyl acetate, polyacrylate, polymethacrylate polyester, polycarbonate, polyvinyl chloride, and polyacetic acid are preferable. Vinyl, polyvinyl acetoacetal, polyvinyl propional,
Polyvinyl butyral, phenoxy resin, epoxy resin, urethane resin, cellulose ester, cellulose ether or the like or a copolymer thereof may be used alone or as a mixture of two or more.

As the solvent, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone are preferable from the viewpoint of the stability of the coating solution and the stability of the crystal type. Esters such as ethyl acetate and butyl acetate, tetrahydrofuran, Ethers such as dioxane, benzene,
It can also be used as a mixture with aromatic hydrocarbons such as toluene and xylene, and aprotic polar solvents such as N, N-dimethylformamide and dimethylsulfoxide.

The thickness of the charge generation layer to be formed is 0.0
It is 5-5 μm, preferably 0.08-1 μm.

Examples of the charge transport material in the charge transport layer include polymer compounds such as polyvinyl carbazole and polysilane, hydrazone compounds, pyrazoline compounds, oxadiazole compounds, stilbene compounds, triphenylmethane compounds, triphenylamine compounds, enamine compounds and the like. Are used.

As a method for forming the charge transport layer, a charge transport material is dissolved in a solvent, a binder resin is added, and in the case of a sheet, a baker applicator, a bar coater, casting, spin coating, or the like. It is manufactured by a mold ring method and a dip coating method.

Examples of the binder resin include vinyl polymers such as polymethyl methacrylate, polystyrene, and polyvinyl chloride, and copolymers thereof, polycarbonate, polyester, polyester carbonate, polysulfone, phenoxy, epoxy, and silicone resins.
These may be used singly or as a mixture of two or more kinds, and a copolymer of a monomer necessary for constituting the resin or a partially crosslinked thermosetting resin may also be used.

Examples of the solvent include halogen solvents such as dichloromethane and 1,2-dichloroethane, ketones such as acetone, methyl ethyl ketone and cyclohexanone, esters such as ethyl acetate and butyl acetate, tetrahydrofuran,
Ethers such as dioxane, aromatic hydrocarbons such as benzene, toluene and xylene, aprotic polar solvents such as N, N-dimethylformamide and dimethylsulfoxide can be used.

The thickness of the charge transport layer to be formed is 5 to 6
0 μm, preferably 10 to 40 μm.

The charge generation layer or the charge transport layer may contain various additives such as a leveling agent, an antioxidant, and a sensitizer as needed. As the antioxidant, vitamin E, hydroquinone, hindered amine, hindered phenol, paraphenylenediamine, arylalkane and derivatives thereof, organic sulfur compounds, organic phosphorus compounds and the like are used.

As the intermediate layer provided between the conductive support and the photosensitive layer, an aluminum anodic oxide film, aluminum oxide,
In addition to inorganic layers such as aluminum hydroxide and titanium oxide, polyvinyl alcohol, polyvinyl butyral, polyvinyl pyrrolidone, polyacrylic acid, celluloses, gelatin, starch, polyurethane, polyimide, polyamide, casein, N-methoxymethylated nylon and the like are used. . Further, particles such as titanium oxide, tin oxide, and aluminum oxide may be dispersed therein, but an intermediate layer containing rutile-type titanium oxide and a polyamide resin as main components is particularly preferable.

Further, an overcoat layer mainly composed of a conventionally known thermoplastic or thermosetting polymer may be provided as the outermost surface layer. Usually, the charge transport layer is formed on the charge generation layer, but the reverse is also possible. As a method for forming each layer, a known method such as sequentially applying a coating solution obtained by dissolving or dispersing a substance to be contained in a layer in a solvent can be applied.

In the case of a single layer type in which a charge generating material is dispersed in a charge transporting layer,
The oxotitanyl phthalocyanine compound of the present invention is dispersed. The particle size in that case must be small enough,
Preferably, it is used at 1 μm or less. If the amount of the charge generating substance dispersed in the photosensitive layer is too small, the sensitivity is insufficient, and if the amount is too large, there are adverse effects such as lowering the chargeability and lowering the sensitivity.
It is used at 5 to 50% by weight, preferably 1 to 20% by weight. The thickness of the photosensitive layer is 5 to 50 μm, preferably 10 to 4 μm.
Used at 0 μm. Also in this case, a known plasticizer for improving film formability, flexibility, mechanical strength, etc., an additive for suppressing residual potential, a dispersion auxiliary for improving dispersion stability, and a coating property. Leveling agents, surfactants such as silicone oils, fluorinated oils,
Other additives may be added.

In the following, the oxotitanyl phthalocyanine of the present invention is compared with a known crystal form of oxo titanyl phthalocyanine. Among the known crystal types, crystal types having relatively good photosensitivity characteristics are Y type and M-α type (in addition, there are I type and M type, which are described in Journal of the Electrophotographic Society, Vol. 32, No. 3) ,
This is a crystal obtained by treating the M-α type as described in p. 232, and has a similar crystal system and characteristics to the M type.
-Included in α-type). However, the new crystal form of the present invention does not coincide with either of these, and is a new crystal form showing good characteristics. That is, the main peak positions of the M-α type are 7.2 °, 14.2 °, and 2 ° at Bragg angles (2θ ± 0.2 °).
The main peaks of the present invention are 7.3 °, 9.4 °, 9.6 °, 11.6 °, 14.0 ° and 27.1 °.
3.3 °, 17.9 °, 24.1 °, 27.2 °, which is another crystal type. The main peak of Y type is 9.6.
°, 11.7 °, 15.0 °, 24.1 °, and 27.1 are similar to the peak positions of the present invention, but the relationship between the relative intensities of the spectra is different. That is, the position of the Y-type maximum peak intensity is 27.3 ° in Bragg angle, whereas the maximum peak position of the present invention is a peak bundle where 9.4 ° and 9.6 ° overlap. (The maximum peak position of the M-α type is 27.3 °.) Further, in the case of the Y type, as shown in FIG. 1 of JP-A-7-27073, the Bragg angle (2θ ± 0.2 °), there are two distinct peaks around 18 ° and 24 °, but in the present invention, the Bragg angle (2θ ± 0.2 °) is 17.9 ° and 24.1 ° is 1 °.
The difference is that only one peak is seen.

Japanese Unexamined Patent Publication (Kokai) No. 8-209023 discloses an oxotitanyl phthalocyanine having a maximum peak at 9.6 ° at a Bragg angle (2θ ± 0.2 °). This oxotitanyl phthalocyanine is a novel crystal form not reported in the Journal of the Electrographic Society of Japan, Vol. 32, No. 3, p. 282. The present inventors have tried to produce this novel oxotitanyl phthalocyanine of the crystalline form, but could not synthesize it and could not compare the photosensitivity and the like, but described in JP-A-8-209923. The main peak position of the Bragg angle of oxotitanyl phthalocyanine is
7.22 °, 9.60 °, 11.60 °, 13.40
°, 14.88 °, 18.34 °, 23.62 °, 2
4.14 ° and 27.32 °, whereas in the crystal form of the present invention 18.34 ° ± 0.2 and 23.62 ° ± 0.2.
There is no peak at 2 °. Therefore, the crystal type is different from the novel crystal type in the present invention.

Since the oxotitanyl phthalocyanine exhibits high sensitivity even in a long wavelength range, it is possible to obtain a photoreceptor having light in a long wavelength range, particularly a photosensitive wavelength optimal for a semiconductor laser and an LED. Further, this oxotitanyl phthalocyanine is characterized in that its crystal form is stable, its crystal stability against solvents and heat is excellent, and its photosensitivity as a photoreceptor and its repeated use characteristics are excellent. These things are
This is a great advantage not only in the production and properties of the above-described oxotitanyl phthalocyanine of the present invention, but also in the production and use of an electrophotographic photosensitive member.

(Examples) The present invention will be specifically described below with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof.

(Production Example 1) 40 g of o-phthalodinitrile
And titanium tetrachloride 18g, α-chloronaphthalene 500m
1 under a nitrogen atmosphere at 200 to 250 ° C. for 3 hours to react and stir. After cooling to 100 to 130 ° C., the mixture is filtered while hot,
Washing with 200 ml of α-chloronaphthalene heated to 100 ° C. gives a crude product of dichlorotitanium phthalocyanine. This crude product is treated with α-chloronaphthalene 2 at room temperature.
After washing with 00 ml and then with 200 ml of methanol, hot washing with 500 ml of methanol is further performed for 1 hour. The crude product obtained after filtration is mixed with 500 ml of water at a pH of 6-7.
, And dried to obtain oxotitanyl phthalocyanine crystals.

This crystal shows an X-ray diffraction spectrum as shown in FIG. CuKα characteristic X-ray (wavelength: 1.541
In the X-ray diffraction spectrum for 8 °), it has a maximum peak at 27.3 ° at its Bragg angle (2θ ± 0.2 °) and at 7.4 °, 9.6 ° and 27.3 °. JP-A-2-8256 and JP-A-7-27 having peaks
It can be seen that it is a crystalline oxotitanyl phthalocyanine called the Y type described in Japanese Patent No. 1073.

The measurement conditions of the X-ray diffraction spectrum were as follows: X-ray source CuKα = 1.54050 ° Voltage 30-40 kV Current 50 mA Start angle 5.0 ° Stop angle 30.0 ° Step angle 0.01-0.02 ° Measurement time 2.0-0.5 ゜ / min. The measurement conditions are the measurement method θ / 2θ scan method. Hereinafter, the measurement conditions of the X-ray spectrum are the same.

The crystals are mixed with methyl ethyl ketone,
Milling with a 2 mm diameter glass bead using a paint conditioner (manufactured by Red Level)
After washing with methanol, the crystals were dried to obtain the crystals of the present invention.

This crystal shows an X-ray diffraction spectrum as shown in FIG. CuKα characteristic X-ray (wavelength: 1.541
In the X-ray diffraction spectrum for 8 °), at the Bragg angle (2θ ± 0.2 °), it has the maximum peak in the overlapping peak bundle of 9.4 ° and 9.6 °, and 7.3.
°, 9.4 °, 9.6 °, 11.6 °, 13.3 °. 1
It can be seen that this is the crystalline oxotitanyl phthalocyanine of the present invention having peaks at 7.9 °, 24.1 °, and 27.2 °.

(Production Example 2) Y obtained in the middle of Production Example 1
Type oxotitanyl phthalocyanine intermediate crystal, polybutyral (Eslek BL-1 manufactured by Sekisui Chemical Co., Ltd.) and vinyl chloride vinyl acetate copolymer resin are mixed with methyl ethyl ketone, and the diameter is adjusted to 2 by a paint conditioner.
Milling treatment was performed together with the glass beads having a diameter of 2 mm, followed by drying to obtain a crystal of the present invention.

This crystal shows an X-ray diffraction spectrum as shown in FIG. In the X-ray diffraction spectrum, at the Bragg angle (2θ ± 0.2 °), there is a maximum peak in the overlapping peak bundle of 9.4 ° and 9.6 °, and 7.3.
°, 9.4 °, 9.6 °, 11.6 °, 13.3 °. 1
Peaks having peaks at 7.9 °, 24.1 °, and 27.2 °, and a peak having a trapezoidal shape from 14.1 ° to 14.9 ° having a plurality of peaks having the same peak intensity. It can be seen that the crystalline oxotitanyl phthalocyanine of the present invention shows an aggregate of peaks that are difficult to separate.

(Production Example 3) Y obtained in the middle of Production Example 1
Type oxotitanyl phthalocyanine intermediate crystal, polybutyral (Eslec BL-1 manufactured by Sekisui Chemical Co., Ltd.) and vinyl chloride vinyl acetate copolymer resin (Eslec M-1 manufactured by Sekisui Chemical Co., Ltd.) are mixed with methyl ethyl ketone, and a paint conditioner is used. Milling treatment was performed with glass beads having a diameter of 2 mm, followed by drying to obtain a crystal of the present invention.

This crystal shows an X-ray diffraction spectrum as shown in FIG. In the X-ray diffraction spectrum, at the Bragg angle (2θ ± 0.2 °), there is a maximum peak in the overlapping peak bundle of 9.4 ° and 9.6 °, and 7.3.
°, 9.4 °, 9.6 °, 11.6 °, 13.3 °. 1
Peaks having peaks at 7.9 °, 24.1 °, and 27.2 °, and a peak having a trapezoidal shape from 14.1 ° to 14.9 ° having a plurality of peaks having the same peak intensity. This shows a group of peaks that are difficult to separate, and a peak having an intensity of about half of the overlapping peak bundle of 9.4 ° and 9.6 ° at the 9.0 ° position as a shoulder peak. It can be seen that this is the crystalline oxotitanyl phthalocyanine of the invention.

(Example 1) An aluminum-evaporated polyester film was used as a conductive support, and titanium oxide and copolymerized nylon (CM8000, manufactured by Toray Industries, Ltd.) were dissolved in a mixed solvent of methyl alcohol and dichloroethane on the support. A coating liquid for forming a layer was prepared, applied and dried to form an intermediate layer having a thickness of 1 μm.

1 part by weight of the crystalline oxotitanyl phthalocyanine of the present invention obtained in Production Example 1 and 1 part by weight of a polybutyral resin (ESREC BL-1 manufactured by Sekisui Chemical Co., Ltd.) were mixed with 70 parts by weight of methyl ethyl ketone. Dispersion treatment was performed using a paint conditioner device (manufactured by Red Level Co., Ltd.) together with glass beads having a diameter of 2 mm, and the obtained solution for forming a charge generation layer was applied onto the intermediate layer and dried to generate a charge having a thickness of 0.4 μm A layer was formed.

Next, the following structural formula [2]

[0062]

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An enamine compound represented by the following formula was mixed with a polycarbonate resin (PCZ-200 manufactured by Mitsubishi Gas Chemical Company) and
1 by weight, and using tetrahydrofuran as a solvent.
A 5 wt% solution was prepared, and then dip coated and dried in the same manner on the charge generation layer to form a charge transfer layer having a thickness of 20 μm. The charge generation layer and the charge transport layer are configured as described above.
A function-separated type photoreceptor sample 1 was obtained.

Example 2 A coating film for forming a charge generation layer prepared in Example 1 was directly applied on an aluminum-evaporated polyester film as a conductive support, and dried to form a film having a thickness of 0.1. A 4 μm charge generation layer was formed.

Next, the following structural formula [3]

[0066]

Embedded image

A function-separated type photoreceptor sample 2 was obtained by dip coating and drying on the charge generation layer using a butadiene compound represented by
I got

(Example 3) A vinyl chloride-vinyl acetate copolymer resin (Slec M-1 manufactured by Sekisui Chemical Co., Ltd.) was used as the resin for the charge generation layer, and the following structural formula [4] was used as the material for the charge transport layer.

[0069]

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A function-separated type photoreceptor sample 3 was obtained in the same manner as in Example 1 except that hydrazone represented by the following formula was used.

Example 4 An aluminum-evaporated polyester film was used as a conductive support, and titanium oxide and copolymerized nylon (CM8000, manufactured by Toray Industries Co., Ltd.) were dissolved in a mixed solvent of methyl alcohol and dichloroethane on the support. A coating liquid for forming a layer was prepared, applied and dried to form an intermediate layer having a thickness of 1 μm.

The solution for forming a charge generation layer containing the crystalline oxotitanyl phthalocyanine of the present invention obtained in Production Example 2 was applied onto the above-mentioned intermediate layer and dried to form a film having a thickness of 0.4 μm.
Was formed.

Next, the enamine compound represented by the above structural formula [2] was converted to a polycarbonate resin (manufactured by Mitsubishi Gas Chemical Company, Ltd.).
PCZ-200) at a weight ratio of 1: 1 to prepare a 15 wt% solution using dichloromethane as a solvent, and dip-coating and drying on the charge generation layer in the same manner to form a charge transfer layer having a thickness of 25 μm. As described above, a function-separated type photoconductor sample 4 composed of the charge generation layer and the charge transport layer was obtained.

Example 5 A butadiene compound represented by the above structural formula [3] was used as a material for the charge transport layer.
A function-separated type photoreceptor sample 5 similar to that of Example 4 was obtained.

Example 6 An aluminum-evaporated polyester film was used as a conductive support, and titanium oxide and copolymerized nylon (CM8000, manufactured by Toray Industries, Ltd.) were dissolved in a mixed solvent of methyl alcohol and dichloroethane on the support. A coating liquid for forming a layer was prepared, applied and dried to form an intermediate layer having a thickness of 1 μm.

The solution for forming a charge generation layer containing the crystalline oxotitanyl phthalocyanine of the present invention obtained in Production Example 3 was applied on the above-mentioned intermediate layer and dried to form a film having a thickness of 0.4 μm.
Was formed.

Next, the enamine compound represented by the above structural formula [2] was converted to a polycarbonate resin (manufactured by Mitsubishi Gas Chemical Company, Ltd.).
PCZ-200) at a weight ratio of 1: 1 to prepare a 15 wt% solution using dichloromethane as a solvent, and dip-coating and drying were similarly performed on the charge generation layer to form a charge transfer layer having a thickness of 25 μm. As described above, a function-separated type photoreceptor sample 6 comprising a charge generation layer and a charge transport layer was obtained.

Example 7 A hydrazone-based compound represented by the above structural formula [4] was used as a material for the charge transport layer.
A function-separated type photoreceptor sample 7 similar to that of Example 6 was produced.

Example 8 An aluminum-evaporated polyester film was used as a conductive support, and titanium oxide and copolymerized nylon (CM8000, manufactured by Toray Industries, Ltd.) were dissolved in a mixed solvent of methyl alcohol and dichloroethane on the support. A coating liquid for forming a layer was prepared, applied and dried to form an intermediate layer having a thickness of 1 μm.

1 part by weight of the crystalline oxotitanyl phthalocyanine of the present invention obtained in Production Example 1 and 10 parts by weight of the enamine compound represented by the above structural formula [2] were mixed with a polycarbonate resin (PCZ-200, manufactured by Mitsubishi Gas Chemical Company).
The mixture was mixed with 0 parts by weight to prepare a 15 wt% solution, which was subjected to a dispersion treatment together with glass beads having a diameter of 2 mm using a paint conditioner. The solution subjected to the dispersion treatment was applied onto the intermediate layer and dried to form a photoreceptor layer having a thickness of 25 μm. As described above, a single-layer photosensitive member sample 8 in which the charge transport material was dispersed in the charge generation layer was obtained.

Comparative Example 1 A function-separated type photoreceptor sample was prepared in the same manner as in Example 1 except that the oxotitanyl phthalocyanine crystal having the X-ray diffraction pattern shown in FIG. 8 obtained in Comparative Production Example 1 was used. 9 was obtained.

Comparative Example 2 A function-separated type photoreceptor sample was prepared in the same manner as in Example 2 except that the oxotitanyl phthalocyanine crystal having the X-ray diffraction pattern shown in FIG. 8 obtained in Comparative Production Example 2 was used. 10 was obtained.

Table 1 summarizes the photoreceptor samples produced in the above Examples and Comparative Examples.

[0084]

[Table 1]

(Evaluation) The electrophotographic photoreceptor thus prepared was an electrostatic recording paper tester (made by Kawaguchi Electric; EPA-8).
200), the electrophotographic properties were evaluated. The measurement conditions are
Applied voltage: -6 kV, Static: No. 3 and monochromatic light of 780 nm (irradiation light:
2MyuW / by cm ^2), were measured exposure E _1/2 necessary for attenuating from -500V to -250V (μJ / cm ²⁾ and the initial potential V ₀ (-V). In addition, a single-layer electrophotographic photoreceptor also uses an electrostatic recording paper tester to measure measurement conditions,
Applied voltage: +6 kV, Static: No. 3, 780 nm monochromatic light (irradiation light: 1
0μW / cm exposure required to attenuate from + 250V to by _{^{+ 500V 2) E 1/2 (μJ}} / cm 2) and was measured the initial potential V ₀ (+ V).

A commercially available digital copying machine (AR5130 manufactured by Sharp Corporation) was modified to set each photoconductor sample, and a continuous blank copy (Non Copy Agine) was performed.
g) was performed 30,000 times, and before and after the measurement, the charging potential and E _1/2 were measured using the electrostatic recording paper test apparatus. Furthermore, continuous blank copy was performed 30,000 times in a high-temperature and high-humidity environment (35 ° C., 85%), and the residual potential was measured before and after that. Table 2 shows the results.

[0087]

[Table 2]

As shown in Table 2, in each of Examples 1 to 8, the deterioration of the potential after the endurance test (30,000 times) of the charging potential of all the samples was smaller than that of Comparative Examples 1 and 2 which were the conventional samples. And the initial sensitivity (half-exposure amount) is sufficiently higher than the comparative example, and the residual potential rise after the durability test (30,000 times) is higher than that of the comparative examples 1 and 2. The feature that it is small enough was confirmed. Further, it can be seen that the residual potential rise after the durability test (30,000 times) under high temperature and high humidity is sufficiently small as compared with Comparative Examples 1 and 2, which are conventional samples.

Next, the evaluation for confirming the solvent stability will be described. The solutions obtained by dispersing the five types of oxotitanyl phthalocyanines described in Examples 1, 3, 4, 6 and Comparative Example 1 were stored at room temperature and refrigerated (5 ° C.), and the change in crystal form was observed. did. The results are shown in Table 3 below.

[0090]

[Table 3]

As shown in Table 3, Examples 1, 3, 4, and 6
The solution obtained by dispersing the oxotitanyl phthalocyanine of
No change in crystal form was observed. However, in Comparative Example 1, which is a conventional sample, in the case of storage at room temperature, A which shows a maximum peak at a Bragg angle of 26.3 ° after one month.
It can be seen that the crystal is dislocated to the type crystal and completely becomes the A type two months later. In addition, in the case of refrigerated storage, it was found that no change was observed after one month, but a change in crystal form to A-type was observed after two months.

[0092]

As described above, according to the present invention, a crystalline oxotitanyl phthalocyanine and an electrophotographic photoreceptor having extremely high sensitivity in a long wavelength region and high durability can be produced. Further, the photoreceptor using the crystalline oxotitanyl phthalocyanine of the present invention, compared with the conventional photoreceptor,
It has a stable crystal form, excellent crystal stability against solvents and heat, that is, excellent solution storage characteristics, excellent photosensitivity characteristics, and excellent repeated use characteristics.

Accordingly, the present invention can provide a photosensitive member which is most suitable for improving the performance of an optical printer or a digital copying machine using a semiconductor laser or an LED array as a light source, which has been remarkably developed recently.

[Brief description of the drawings]

FIG. 1 is a diagram showing a function-separated type photoconductor comprising two layers, a charge generation layer and a charge transport layer.

FIG. 2 is a diagram showing a function-separated type photoconductor comprising an intermediate layer and three layers of a charge generation layer and a charge transport layer.

FIG. 3 is a diagram illustrating a single-layer type photoconductor in which a charge generating substance is dispersed in a charge transport layer.

FIG. 4 is a diagram showing a single-layer type photoreceptor in which a charge generating substance is dispersed in an intermediate layer and a charge transport layer.

FIG. 5 is an X-ray diffraction spectrum of oxophthalocyanine obtained in Production Example 1 of the present invention.

FIG. 6 is an X-ray diffraction spectrum of oxophthalocyanine obtained in Production Example 2 of the present invention.

FIG. 7 is an X-ray diffraction spectrum of oxophthalocyanine obtained in Production Example 3 of the present invention.

FIG. 8 is an X-ray diffraction spectrum of an oxophthalocyanine intermediate crystal obtained during the production of Production Example 1 of the present invention.

FIG. 9 is an X-ray diffraction spectrum of a solution obtained by a dispersion treatment of an oxophthalocyanine intermediate crystal obtained during the production in Production Example 1 of the present invention one month after storage at room temperature.

FIG. 10 is an X-ray diffraction spectrum of a solution obtained by a dispersion treatment of an oxophthalocyanine intermediate crystal obtained during the production in Production Example 1 of the present invention two months after storage at room temperature.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 conductive support 2 charge generating material 3 charge transporting material 4, 4 ′ photosensitive layer 5 charge generating layer 6 charge transporting layer 7 intermediate layer

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Takahiro Teramoto Inventor 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka F-term (in reference) 2H068 AA19 AA21 AA28 BA39 FB07

Claims (5)

[Claims] In an X-ray diffraction spectrum, a Bragg angle (2θ ± 0.2 °) is 7.3 °, 9.4 °, 9.6.
゜, 11.6 ゜, 13.3 ゜, 17.9 ゜, 24.1
A crystalline oxotitanyl phthalocyanine having a main peak at {27.2}, wherein the overlapping peak bundle of 9.4 ° and 9.6 ° is the maximum peak, and the peak at 27.2 ° is Crystalline oxotitanyl phthalocyanine, which is the second maximum peak. 2. The peak intensity at 27.2 ° is 9.
80 of peak intensity of 4 ° and 9.6 ° overlapping peak bundles
% Or less, crystalline oxotitanyl phthalocyanine according to claim 1, wherein 3. In the X-ray diffraction spectrum, its Bragg angle (2θ ± 0.2 °) is from 14.1 ° to 14.3 °.
The crystalline oxotitanyl phthalocyanine according to claim 1 or 2, wherein the crystalline oxotitanyl phthalocyanine exhibits a trapezoidal peak bundle at 9 °. 4. In the X-ray diffraction spectrum, at a Bragg angle (2θ ± 0.2 °) of 9.0 °, an intensity of about half of the overlapping peak bundle of 9.4 ° and 9.6 °. The crystalline oxotitanyl phthalocyanine according to any one of claims 1 to 3, which has a shoulder peak of the following. 5. An electrophotographic photoreceptor using the crystalline oxotitanyl phthalocyanine according to claim 1 as a charge generation material.