JP3230176B2 - Image forming method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming method by reversal development employed in an image forming apparatus such as a laser printer using a specific organic photoreceptor.

[0002]

2. Description of the Related Art In recent years, digitalization techniques have been developed, and image forming apparatuses such as digital copiers and laser beam printers have been actively developed. Reversal development has been performed using a photoreceptor.

In the reversal developing method, generally, after charging the surface of the electrophotographic photosensitive member to a predetermined polarity voltage by corona discharge or the like using a charger, the uniformly charged electrophotographic photosensitive member is removed. Exposure is performed by an exposure device, and the surface potential of the electrophotographic photosensitive member at the exposed portion is reduced.
Next, a toner charged to the same polarity as the charged polarity of the electrophotographic photosensitive member is supplied from the developing device to the surface of the electrophotographic photosensitive member, and the toner is applied to the exposed portion of the electrophotographic photosensitive member having a reduced surface potential. And forming a visualized toner image on the surface of the electrophotographic photosensitive member.

At this time, in the case of the image forming method by the reversal development, unnecessary irradiation time of the laser beam can be cut, so that the temperature inside the image reading section can be kept low, and the life of the laser light source can be maintained long. Further, it is also possible to prevent the "sludge" of the scanning caused by the exposure irradiation of the non-image portion.

However, as described above, this reversal development causes toner to adhere to the image portion having a low potential, so that if the photosensitive layer itself has a defect, the charged non-image portion is not originally used. Although the potential is high, the potential remains locally low, and the toner adheres to a locally defective portion due to reversal development, which causes a so-called "black spot" on a white background.

On the other hand, in recent years, various electrophotographic photosensitive members have been used as electrophotographic photosensitive members used in the above-described image forming apparatuses.

The photoconductive materials used in these photoconductors tend to shift from inorganic to organic photoconductors (OPC) using organic photoconductive materials (PCM), and furthermore, photoconductive materials for carrier generation and carrier transport. The sexual function is separated into a carrier generating substance (CGM) and a carrier transporting substance (CTM), respectively. In addition to the single layer structure in which CGM and CTM are mixed and dispersed,
A photoreceptor having a structure in which a carrier generation layer (CGL) containing CGM and a carrier transport layer (CTL) containing CTM are stacked is also used.

[0008] Among the CGMs used for these, those having absorption in a long wavelength region of 600 nm or more are advantageous for a semiconductor laser beam printer due to the light source. One of them is a perylene compound, particularly a perylene derivative (BIP) into which imidazolopyridone has been introduced (Japanese Patent Publication Nos. 61-8423, 59-59686, 63-180956, and 63-180956;
63-291061).

However, although the perylene derivative has relatively good sensitivity, when an image is formed by a reversal development method, fog and black spots are liable to be generated on a solid white portion, and the density is reduced by repeating the process many times. Fog rises and black spots increase.

[0010] Further, these various performances depend on environmental conditions (temperature and humidity).
In some cases, it is worse than normal temperature and normal humidity.

The imidazole perylene compound of the general formula [1] or [2] constituting the present invention is disclosed in JP-B-61-8423.
No. (US Pat. No. 3,972,717) discloses a technique for use as a carrier-generating substance. Thereafter, many electrophotographic photoreceptors using this compound as a carrier-generating substance have been studied. JP-A-59-59686 discloses a technique for preparing a photoreceptor by mainly dispersing and coating the present compound.
848 (U.S. Pat.No. 4,587,189), JP-A-63-180956,
JP-A-63-291061, JP-A-4-186363, JP-A-4-18636
No. 4 discloses a technique using the present compound in combination with a specific carrier transporting substance. In addition, Japanese Patent Laid-Open No.
JP-A-4-204850 discloses a technique for atomizing the present compound by acid paste treatment.
-41054 discloses a technique of using a perylene-based compound containing the present compound by sublimation purification.

However, in these prior arts, no study has been made on the crystal state of the present compound, so that sufficient sensitivity characteristics cannot be brought out, and it has not been possible to respond to the recent demand for higher sensitivity. .

Regarding the crystal form of the compound of the general formula [1] or [2], several X-ray diffraction spectra are disclosed in J. Imag. Sci., Vol. 33, P151-159 (1989). . However, these are related to powder crystals, and in the study of the present inventors, when a photoreceptor coating solution was prepared using these powders, the photoreceptor coating solution depends on the conditions of preparation of the coating solution and the chemical purity. The X-ray diffraction spectrum of the product changes,
At the same time, it was found that the characteristics of the photoreceptor also changed significantly.

From this point of view, Japanese Patent Application Laid-Open Nos. H5-249719 and H5-281769 disclose a technique for controlling the crystal state of the compound. These techniques adjust the crystal state by a dry grinding method.However, since such a dry grinding involves a strong local shearing force, there is a problem in homogenization of the grinding, and black spots appear on the electrophotographic image. There is a disadvantage that it is easy to occur. Further, in the dry pulverization, a crystal defect is easily introduced due to a large mechanical impact on the crystal powder, and as a result, the charge potential holding ability is reduced. Thus, the crystal control technology is still insufficient for this compound,
Its performance has not been exploited.

[0015]

The object of the present invention is to provide (1)
It has high spectral sensitivity up to the long wavelength range, has no image defects, has high image quality, (2) does not cause image defects and image quality deterioration due to repeated use, and (3) has an environmentally stable image obtained by a reactive development method. It is to provide a forming method.

[0016]

That is, an object of the present invention is to provide at least one of the following general formula [1] or general formula [2] on a conductive support, and an X-ray diffraction spectrum for Cu-Kα ray. Bragg angle 2θ is 6.3 ± 0.2 °, 12.4 ± 0.2 °, 25.
With peaks at 3 ± 0.2 ° and 27.1 ± 0.2 °, 12.4 ± 0.2 °
Up has a peak intensity, and a half value of the peak of 0.65 or more and 11.5 have a crystal form which does not have a clear peak in the ± 0.2 °, and after the purification by sublimation, acid paste punished
After the physical perylene pigment imparted a uniform charge on the photosensitive member comprising a photosensitive layer provided comprising as a carrier generating substance, to form an electrostatic latent image by exposure, then the unit performs a reversal development This is achieved by the following image forming method.

[0017]

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In the general formula [1] or [2] representing the perylene pigment having the specific structure, preferred examples of the divalent aromatic ring represented by Z include, for example, a benzene ring, a naphthalene ring, an anthracene ring, and a phenanthrene ring. Ring, pyridine ring, pyrimidine ring, pyrazole ring, anthraquinone ring and the like, and particularly preferably a benzene ring or a naphthalene ring. The aromatic ring represented by Z may be substituted. Examples of the substituent include an alkyl group, an alkoxy group, an aryl group, an aryloxy group, an ashile group, an acyloxy group, an amino group, a carbamoyl group, and a halogen group. , A nitro group, a cyano group and the like.

Hereinafter, specific examples of the perylene compound preferably used in the present invention will be shown, but the present invention is not limited by these.

[0020]

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These exemplified compounds are described, for example, in
It is synthesized by the methods described in JP-A-49-128734 and JP-A-59-569686.

In general, in order to obtain highly sensitive photoreceptor characteristics, first, it is necessary to obtain a uniform coating film in which a carrier generating substance is atomized. That is, the first important thing in the dispersion atomization step is to atomize the carrier generating substance. However, as a result of investigations by the present inventors, the perylene pigment of the general formula [1] or [2] of the present invention has a strong sensitizing effect due to atomization, and depending on the manner of atomization, strong permeation added for particle crushing. The shear force may cause physical damage to the inside or surface of the crystal, resulting in a desensitizing effect, and as a result, the sensitivity characteristic may rather show a remarkable tendency to decrease. Therefore, it is preferable that the atomization of the pigment proceeds with as little shearing force as possible. In the present invention, the acid paste treatment is performed, the particle size is small,
It is preferable to use pigments having the same size.

The crystal form of the imidazole perylene compound used in the present invention is described in J. Imag. Sci., Vol.
159 (1989) discloses four types of X-ray diffraction spectra called α, γ, ε, and ρ. Basically, α-type and ε-type have similar crystal structures, but it is clear that ρ-type is a completely different crystal. The crystal state of the present invention is based on this ρ-type crystal. The change in state that occurs in the step of dispersing and pulverizing the ρ-type crystal in an organic solvent has a significant effect on the sensitivity characteristics.

When the crystallite size becomes smaller than a certain size by dispersing and atomizing, broadening of the diffraction peak and reduction of the peak intensity occur in the X-ray diffraction spectrum. The ρ-type crystal of the imidazole perylene compound is Cu
6.3 ± 0.2 in X-ray diffraction spectrum against -Kα ray
The peaks at °, 12.4 ± 0.2 °, 25.3 ± 0.2 °, and 27.1 ± 0.2 ° are characteristic, but there is also a unique peak at 11.5 ± 0.2 °. When the ρ-type crystal is dispersed and refined, broadening of the entire peak can be seen, but what is particularly important in the present invention is that the half width of the peak at 12.4 ± 0.2 ° becomes 0.65 ° or more. . In order to show good characteristics as a carrier generating substance of the photoconductor, the peak of 12.4 ± 0.2 ° broadened in this way is 11.5 ± 0.2 °
Is buried, and it is necessary that the peak is not recognized in the region of 11.5 ± 0.2 °. However, 12.4 ± 0.2
If the half width of the peak at 1.5 ° exceeds 1.5 °, it cannot be said that the crystal is in the ρ-type crystal state, and the characteristics are deteriorated.

The photoreceptor characteristics of the imidazole perylene compound of the present invention depend on the crystalline state characterized by the relative intensity of the peak in the X-ray diffraction spectrum. The imidazole perylene compound is 6.3 at the stage of synthesis.
The peak intensity around ° is often the maximum, and the sublimated peak intensity at 25-28 °
The peak intensity at 12.4 ° may be maximum. However, when these are dispersed and atomized in an organic solvent, the relative intensity of each peak changes, and thus the photoconductor characteristics change.
The crystal of the present invention can obtain particularly excellent sensitivity characteristics by maximizing the peak intensity at 12.4 ± 0.2 ° of the X-ray diffraction spectrum.

That is, in the present invention, 12.4 ± 0.2
The peak half-value width of ° is 0.65 ° or more, and 11.5 ± 0.
After pulverization to a state where no clear peak is shown at 2 °, a state where the peak intensity at 12.4 ± 0.2 ° is maximum is used.

The method for obtaining such a crystalline state of the carrier-generating substance is not particularly limited, but the most excellent method for preventing defects in an electrophotographic image as seen in a dry grinding method is sublimation purification. The perylene compound is subjected to acid paste treatment (amorphization or low crystallization) using sulfuric acid, and this is gently dispersed in a high-affinity organic solvent with a polymer binder interposed between the perylene compound and the target crystal while growing the crystal. State. In this method, uniform atomization is achieved, and a reduction in characteristics due to the introduction of crystal defects can be avoided due to a small mechanical impact.

The imidazole perylene compound represented by the general formula [1] or [2] can be synthesized by a dehydration condensation reaction between perylene-3,4,9,10-tetracarboxylic dianhydride and o-phenylenediamine.

The synthesized imidazole perylene compound is subjected to sublimation purification to remove impurities. The sublimation operation is repeated once to about 5 to 6 times, but it is preferable to repeat the sublimation operation two or more times. When a coating solution is prepared without performing sublimation purification, it is difficult to obtain the crystalline state of the present invention. The imidazole perylene compound obtained by sublimation shows a sharp peak pattern in the X-ray diffraction spectrum, confirming that the compound has a high crystallinity.

The high crystallinity imidazole perylene compound obtained by sublimation purification is converted to a low crystallinity state by performing acid paste treatment using sulfuric acid. That is, after dissolving in concentrated sulfuric acid, the solution is poured into a poor solvent such as water or methanol to cause precipitation, and this is filtered and dried to obtain fine particles of low crystalline fine particles.

The low crystalline powder after the acid paste treatment is subjected to a dispersion treatment in a solvent having a high affinity for the imidazole perylene compound using a suitable disperser. Examples of the solvent having a high affinity include a ketone solvent having 4 to 8 carbon atoms, a cyclic ether solvent having 4 to 7 carbon atoms, or a solvent having 2 carbon atoms.
Use of from 4 to 4 halogenated hydrocarbon solvents is useful. Among them, particularly preferred solvents include methyl ethyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, cyclohexanone, tetrahydrofuran, dichloroethane, and trichloroethane. In this dispersion treatment, good results can be obtained by the presence of an appropriate binder polymer.

Particularly preferred binder polymers include polyvinyl acetal resins such as polyvinyl butyral and polyvinyl formal, vinyl chloride-vinyl acetate resins, polyester resins, polycarbonate resins, acrylic resins and methacrylic resins, acrylic and methacrylic copolymer resins, silicone resins, and the like. Examples include silicone copolymer resin, polystyrene, styrene copolymer resin, phenoxy resin, phenol resin, urethane resin, epoxy resin and the like.

The specific crystalline state of the present invention is realized in the dispersion coating solution obtained by such a method. In this method, high purification by sublimation purification is important for adjusting the crystal state during dispersion, and this is further made amorphous by acid paste treatment with sulfuric acid. In the process of dispersion treatment, the amorphous state (or low crystalline state) is obtained. )
Thus, the crystal is grown by a specific solvent effect, whereby the specific crystal state of the present invention can be stably obtained from a completely different viewpoint.

A photoreceptor is prepared using the obtained dispersion coating solution. Whether or not the crystalline state of the present invention is realized in the photoconductor is determined by the X of the perylene compound peeled from the photoconductor.
It can be confirmed by measuring a line diffraction spectrum. Since no change in the crystal state occurs in the process of coating the photoreceptor, it can be confirmed by removing the solvent from the dispersion coating solution and measuring the X-ray diffraction spectrum.

These samples are measured by a powder X-ray diffractometer using Cu-Kα radiation as an X-ray source, and a diffraction line intensity distribution is obtained as a function of the Bragg angle 2θ. At this time, when the sample amount is sufficient, the relative intensity ratio between the peak intensities does not change depending on the sample amount, but as the sample amount decreases, the peak intensity on the low angle side relatively increases. Therefore, in the measurement, a sufficient amount of the sample must be used so that the peak intensity ratio does not change with the sample amount.

As a method for adjusting crystals having an X-ray spectrum peculiar to the above-mentioned perylene pigment, a desired crystal form can be obtained by selecting a dispersion solvent and a dispersion method such as strength of dispersion.

The crystal type used in the present invention has few carrier recombination and traps and has good dispersion suitability.
It has few image defects and high sensitivity and high image quality.

The average particle size of the crystals of the compound used in the present invention is 0.5 μm or less, preferably 0.01 to 0.3 μm, more preferably 0.05 to 0.
2 μm.

Various configurations of the photosensitive member are known.

Although the present invention can take any of these forms of the photoreceptor, it is desirable to use a laminated type or a dispersed type function-separated type photoreceptor. In this case, usually, FIG.
The configuration is as shown in FIG. The layer configuration shown in FIG. 3A is obtained by forming a carrier generation layer 2 on a conductive support 1 and laminating a carrier transport layer 3 thereon to form a photosensitive layer 4. 4) shows a photosensitive layer 4 'in which the carrier generation layer 2 and the carrier transport layer 3 are reversed. FIG. 3C shows that an intermediate layer 5 is provided between the photosensitive layer 4 having the layer configuration of FIG. 4A and the conductive support 1, and FIG. Intermediate layer 5 between porous support 1
Is provided. The layer structure shown in FIG. 4E is obtained by forming a photosensitive layer 4 ″ containing a carrier generating substance 6 and a carrier transporting substance 7, and FIG. 4F shows such a photosensitive layer 4 ″ and a conductive support. 1 is provided with an intermediate layer 5. 3A to 3F, a protective layer can be further provided on the outermost layer.

The protective layer may contain CTM, and may have a so-called two-layer CTL structure.

The solvent or dispersion medium used for forming the carrier generating layer 2 includes n-butylamine, diethylamine, ethylenediamine, isopropanolamine, triethanolamine, triethylenediamine, N, N-dimethylformamide, acetone, methylethylketone, methyl Isobutyl ketone, cyclohexanone, benzene,
Toluene, xylene, chloroform, 1,2-dichloroethane, 1,2-dichloropropane, 1,1,2-trichloroethane,
1,1,1-trichloroethane, trichloroethylene, tetrachloroethane, dichloromethane, tetrahydrofuran,
Dioxane, methanol, ethanol, isopropanol, ethyl acetate, butyl acetate, dimethyl sulfoxide,
Methyl cellosolve and the like are mentioned, and are selected so as to have the above-mentioned crystal structure.

The carrier transporting layer 3 containing at least a carrier transporting substance can be formed in the same manner as the carrier generating layer 2.

As the binder resin used for forming the carrier generating layer 2 or the carrier transporting layer 3, any one can be used, but it is preferable to use a hydrophobic, electrically insulating film-forming polymer. . Examples of such a high molecular polymer include the following, but are not limited thereto.

P-1) Polycarbonate P-2) Polyester P-3) Methacrylic acid P-4) Acrylic resin P-5) Polyvinyl chloride P-6) Polyvinylidene chloride P-7) Polystyrene P-8) Polyvinyl acetate P-9) Styrene-butadiene copolymer P-10) Vinylidene chloride-acrylonitrile copolymer P-11) Vinyl chloride-vinyl acetate copolymer P-12) Vinyl chloride-vinyl acetate-maleic anhydride copolymer P -13) Silicon resin P-14) Silicon-alkyd resin P-15) Phenol-formaldehyde resin P-16) Styrene-alkyd resin P-17) Poly-N-vinylcarbazole P-18) Polyvinyl butyral These binder resins are used alone. Or a mixture of two or more.

In the carrier generation layer 2 formed as described above, the mixing ratio of the pigment and the binder resin is as follows:
The weight ratio of the pigment to the binder resin is set to 100: 0 to 1000. If the content of the perylene pigment is less than this, the photosensitivity is low and the residual potential is increased. descend.

When the carrier generating layer 2 contains a carrier transporting substance, the ratio of the carrier generating substance to the carrier transporting substance is preferably from 10: 0 to 10: 1000 by weight, and particularly preferably. Is from 10: 0 to 10: 100.

The thickness of the carrier generating layer 2 to be formed is preferably 0.01 to 10 μm.

In the carrier transporting layer 3 formed as described above, the carrier transporting material is preferably 20 to 200 parts by weight, particularly preferably 30 to 150 parts by weight, per 100 parts by weight of the binder resin in the carrier transporting layer 3. Department.

The thickness of the carrier transport layer 3 to be formed is preferably 5 to 60 μm, particularly preferably 10 to 40 μm.

The carrier transporting substance used in the present invention is not particularly limited.
Oxadiazole derivative, thiazole derivative, thiadiazole derivative, triazole derivative, imidazole derivative, imidazolone derivative, imidazolidine derivative, bisimidazolidine derivative, styryl derivative, hydrazone compound, pyrazoline derivative, amine derivative, oxazolone derivative, benzothiazole derivative, benzimidazole Derivatives, quinazoline derivatives, benzofuran derivatives, acridine derivatives, phenazine derivatives, aminostilbenzene derivatives, poly-N-vinylcarbazole, poly-1-vinylpyrene, poly-9-vinylanthracene, and the like.

The carrier transporting substance contained in the carrier transporting layer 3 includes, in addition to the ability to transport holes generated upon light irradiation to the surface of the photoreceptor, a carrier generating substance comprising the unique perylene pigment according to the present invention. The combination is preferably selected in consideration of the combination. Examples of such a carrier transporting substance include JP-A-58-65440 and JP-A-58-65440.
Styryl compounds described in JP-A-198043, JP-A-58-1346
No. 42 and JP-A-59-166354, and cyclic hydrazone compounds described in JP-A-57-67940 and JP-A-57-67940.
A chain hydrazone compound described in JP-A-101844, a carbazole compound described in JP-A-57-148750, or a distyryl-based compound described in JP-A-64-32265.

The conductive support 1 used in the photoreceptor according to the present invention may be a metal plate, a metal drum or a conductive polymer containing an alloy, a conductive compound such as indium oxide, or aluminum, palladium containing an alloy. Paper, plastic film, etc., which are made conductive by applying, depositing or laminating a thin metal layer such as gold. As the intermediate layer 5 such as an adhesive layer or a barrier layer, an organic polymer substance such as polyvinyl alcohol, ethylcellulose, carboxymethylcellulose, or polyamide, or aluminum oxide is used in addition to the polymer used as the binder resin.

In the photoreceptor according to the present invention, for the purpose of improving the carrier generating function of the carrier generating substance, an organic amine described in, for example, JP-A-60-172044 is incorporated in the photosensitive layer 4 into the photosensitive layer. It can be contained at 1 time or less, preferably 0.2 to 0.005 times. Also improved sensitivity,
For the purpose of reducing residual potential or fatigue during repeated use, 0.01 to 200 parts by weight, preferably 0.1 to 100 parts by weight, of the electron-accepting substance described in the above publication in 100 parts by weight of the carrier generating substance is contained in the carrier generating layer 2. It can be contained.

Next, a preferred embodiment of the present invention will be described.

FIG. 4 is a schematic diagram showing an example of a recording apparatus for performing the method of the present invention, and FIG. 5 is a schematic diagram showing an example of a developing device.

In the apparatus shown in FIG. 4, reference numeral 10 denotes a drum-shaped image bearing member having a photosensitive layer of the above-mentioned organic photoconductive substance and rotating in the direction of the arrow, and chargers 11, 12 for uniformly charging the surface of the drum. Denotes an image exposure, and 13 denotes a developing device. Reference numeral 14 denotes a pre-transfer exposure lamp provided as necessary to facilitate the transfer of an image having a toner image formed on the image carrier 10 onto the recording paper P, 15 denotes a transfer device, 16 denotes a corona discharge device for separation, A fixing device 19 fixes the toner image transferred to the recording paper P. Reference numeral 17 denotes a static eliminator comprising one or a combination of a static elimination lamp and a corona discharger for static elimination, and 18 includes a cleaning blade and a fur brush for removing residual toner on the surface of the image carrier 10 after transferring the image. It is a cleaning device.

As the developing unit 13, one having a structure as shown in FIG. 5 is preferably used. In FIG. 5, the developer D is conveyed in the direction of arrow G by rotating the magnetic roll 21 in the direction of arrow F and the developing sleeve 20 in the direction of arrow G. The thickness of the developer D is controlled by the layer thickness regulating blade 22 during conveyance.
Is regulated. The layer thickness regulating blade 22 is made of an elastic metal plate and presses the surface of the developing sleeve 20 to control the thickness of the conveyed developer. A stirring screw 23 is provided in the developer reservoir 25 so that the developer D is sufficiently stirred. When the developer D in the developer reservoir 25 is consumed, the toner supply roller 24 rotates. Thus, the toner T is supplied from the toner hopper 26. A bias power supply 27 for applying a developing bias to the developing sleeve 20 and a protective resistor 28 are connected in series. Further, the developing sleeve 20 and the image carrier
10, the developer is in contact with the image carrier 10 in the developing area E, and t> d.

FIG. 5 shows that the developing sleeve 20 and the magnetic roll 21 rotate in the directions of arrows G and F, respectively. However, even if the developing sleeve 20 is fixed, the magnetic roll 21 is not fixed. Alternatively, the developing sleeve 20 and the magnetic roll 21 may rotate in the same direction. When the magnetic roll 21 is fixed, usually, the image carrier
In order to make the magnetic flux density of the magnetic pole facing 10 larger than the magnetic flux density of the other magnetic poles, it is necessary to strengthen the magnetization or to place two magnetic poles in close proximity to the same or different pole. Will be

Then, the recording paper P is guided to the image carrier 10 in which the latent image on the photoconductor surface has been visualized by development, and the toner image formed on the surface of the image carrier 10 is transferred by the transfer unit 15 to the recording paper P. Transfer onto P. The recording paper P on which the toner image has been transferred as described above is guided to a fixing device 19, and the fixing device 19 fixes the toner on the recording paper P, while removing the toner remaining on the surface of the electrophotographic photosensitive member after the transfer. It is removed by the cleaning device 18.

The image formation of the present invention is performed by light exposure using a light source such as a halogen lamp, a tungsten lamp, an LED (light emitting diode), a laser beam, or a liquid crystal array.

[0062]

EXAMPLES The present invention will be described below in more detail with reference to Examples, but the embodiments of the present invention are not limited thereto.

(Synthesis Example) 39.2 g of perylene-3,4,9,10-tetracarboxylic dianhydride, 32.4 g of o-phenylenediamine,
800 ml of α-chloronaphthalene was mixed and reacted at 260 ° C. for 6 hours. After cooling, the precipitated crystals were collected by filtration and washed repeatedly with methanol. By heating and drying, Exemplified Compound A-1 was synthesized.

(Sublimation Example) The exemplified compound A-1 obtained in the above synthesis example was subjected to sublimation purification under a heating condition of 500 ° C. under a pressure of 5 × 10 ^{−4 to} 5 × 10 ⁻³ torr. Volatile impurities were removed using a shutter. The obtained purified crystals were again subjected to the same sublimation treatment to further purify the crystals. A product that has been subjected to two sublimation operations in this manner is referred to as a sublimated product (SUB product) of Exemplified Compound A-1.

(Example of Acid Paste Treatment) A solution prepared by dissolving 20 g of the sublimation product of Exemplified Compound A-1 in 600 ml of concentrated sulfuric acid was filtered through a glass filter, and then dropped into 1200 ml of pure water to precipitate. This was collected by filtration, washed thoroughly with pure water, and dried. The compound thus obtained was used as an exemplary compound A
-1 Acid paste treated product (AP product).

(Preparation of Photoconductor 1) Polyamide resin “CM
30 g of "-8000" (manufactured by Toray Industries, Inc.) was placed in a mixed solvent of 900 ml of methanol and 100 ml of 1-butanol, and dissolved by heating at 50 ° C. After cooling to room temperature, using this liquid, outer diameter 80 mm,
An intermediate layer having a thickness of 0.5 μm was formed by dip coating on an aluminum drum having a length of 355.5 mm. Next, polyvinyl butyral resin "S-LEC BLS" (Sekisui Chemical Co., Ltd.)
6 g of methyl ethylene ketone (manufactured by Kanto Chemical Co., Ltd.) 1000 ml
AP-1 of Exemplified Compound A-1 obtained by the above-described method as a carrier generating substance (CGM).
g, and then dispersed with a sand mill (SG) for 15 hours together with 2000 g of glass beads having a diameter of 1 mm to obtain a dispersion liquid 1. Using this solution, the carrier generation layer (CGL) having a thickness of 0.3 μm was formed by dip coating on the intermediate layer.

The dispersion obtained at this time was applied on a glass plate a plurality of times and dried to produce a dried film having a thickness of about 200 μm, and the X-ray diffraction spectrum was measured using Cu-Kα rays. When the black angle 2θ was 6.3 ± 0.2 °, 1
It has peaks at 2.4 ± 0.2 °, 25.3 ± 0.2 °, and 27.1 ± 0.2 °, has a maximum peak intensity at 12.4 ± 0.2 °, and has a half width of 0.86 ° and a clear peak at 11.5 ± 0.2 °. It was found that no significant peak was shown. The dried film was peeled off, and the average particle size was measured by an electron microscope photograph to find that it was 0.15 μm. Then the carrier transport material (CT
M) A compound T-1 having the following structure; 200 g of a polymer resin B having the following structure as a binder, and 200 g of a polymer resin having the following structure dissolved in 1000 ml of cyclomethane were dip-coated on the CGL to form a 20 μm-thick carrier transport layer ( CTL). Then heat and dry at 100 ° C for 1 hour,
And the photoreceptor 1 of Table 1 (for Example 1) having CTL.

The X-ray diffraction spectrum (XRD) of the dispersion 1 is shown in FIG.

[0069]

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(Preparation of Photoreceptor 2) Dispersion liquid 2 was obtained by using 1,2 dichloroethane in place of the solvent methyl ethyl ketone for the dispersion liquid 1 and dispersing the glass beads in a sand mill for dispersion to 2500 g for 20 hours. Photoconductor 2 (for Example 2) in Table 1 was obtained in the same manner as photoconductor 1, except that CGL was prepared using dispersion 2.

When the X-ray diffraction spectrum of the dispersion 2 was measured in the same manner as in the case of the photoreceptor 1, as shown in Table 1, the dispersion 2 had the maximum peak intensity at 12.4 ± 0.2 ° and the half width of the peak. Was 0.94 °, showing no clear peak at 11.5 ± 0.2 °. When the average particle size of the pigment was measured in the same manner as in the case of Photoconductor 1, it was 0.06 μm.

(Preparation of Photoreceptor 3)
2 While using tetrahydrofuran instead of dichloroethane, the amount of glass beads
g, and dispersed for 10 hours to obtain Dispersion 3. Photoconductor 3 (for Example 3) in Table 2 was obtained in the same manner as Photoconductor 2 except that Dispersion 3 was used.

When the X-ray diffraction spectrum of the dispersion 3 was measured in the same manner as in the case of the photoreceptor 1, as shown in Table 1, the dispersion 3 had the maximum peak intensity at 12.4 ± 0.2 ° and the half width of the peak was 0.68 °, indicating no clear peak at 11.5 ± 0.2 °. When the average particle size of the pigment was measured in the same manner as in the case of the photoreceptor 1, it was 0.30 μm.

(Preparation of Photoconductor 4) CTL of Photoconductor 1
Is a compound T- having the following structure in place of the compound T-1
2 in the same manner as photoconductor 1 except that photoconductor 4 in Table 2 was replaced.
(For Example 4) was obtained.

[0075]

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(Preparation of Photoreceptor 5) A dispersion 4 was obtained in the same manner as the dispersion 1 except that the dispersion 1 was dispersed for 5 hours by using an ultrasonic disperser instead of a sand mill as a dispersing means.
Photoreceptor 5 in Table 2 (for Comparative Example 1) was obtained in the same manner as for photoreceptor 1, except that this dispersion was used.

When the X-ray diffraction spectrum of the dispersion 4 was measured in the same manner as in the case of the photoreceptor 1, the peak intensity at 12.4 ± 0.2 ° was the maximum as shown in Table 1, and the half width of the peak was Was found to be 0.60 ° and a clear peak at 11.5 ± 0.2 °. When the average particle size of the pigment was measured in the same manner as in the case of Photoreceptor 1, it was 0.60 μm.

(Preparation of Photoreceptor 6) The same procedure as in Dispersion 1 was performed, except that the sublimation product (SUB product) of Exemplified Compound A-1 was used instead of the AP product of Exemplified Compound A-1 of Dispersion 1. Dispersion 5 was obtained. Photoconductor 6 in Table 2 (for Comparative Example 2) was obtained in the same manner as photoconductor 2, except that dispersion 5 was used.

When the X-ray diffraction spectrum of the dispersion 5 was measured in the same manner as in the case of the photoreceptor 1, as shown in Table 1, it did not have the maximum peak intensity at 12.4 ± 0.2 °,
It was found that it had the maximum peak intensity at ± 0.2 °, the half-width at half maximum of the peak at 12.4 ± 0.2 ° was 0.68 °, and no clear peak at 11.5 ± 0.2 ° (see FIG. 2). .
The average particle size of the pigment was measured in the same manner as in the case of Photoconductor 1, and it was 0.55 μm.

[0080]

[Table 1]

[0081]

[Table 2]

Examples 1 to 4 and Comparative Examples 1 and 2 Each of the photoconductors of the present invention and the comparative example was named "KONICA U-BIX 1550MR".
(Remodeled with Konica's LED light source with a wavelength of 660 nm), and adjusted the grid voltage so that _VH (photoconductor charging voltage) became -600 ± 10 (V).
Reverse development with 0 (V) + AC2000 (V) (1 kHz), 10,000 copies at high temperature and high humidity (30 ° C., 80 RH%), black spots on the white background and black background (the original The image density _Dmax of the portion corresponding to the white background portion) was evaluated.

[0083] The evaluation of the black spots is determined by measuring the particle size and the number of black spots with an image analyzer "Omunikon 3000 form" (manufactured by Shimadzu Corporation), 1 cm ² is black spots more than the diameter 0.05mm
Judgment was made based on how many pieces per hit.

The criteria for determining the black spots are as shown in Table 3.

[0085]

[Table 3]

If the result of the black spot determination is ◎ or ○, it is practical, but if it is △ or ×, it is not suitable for practical use.

Table 4 below shows the results of the evaluation of black spots on each photosensitive member.

[0088]

[Table 4]

From the results shown in Table 4, it can be seen that when a copy image is formed in accordance with the present invention, black spots are remarkably reduced in reversal development, and a high-quality image with high image density and no fog can be formed. .

[0090]

According to the structure of the present invention, it is possible to obtain a photosensitive member for a printer, a digital copying machine, and a facsimile machine, which has high sensitivity and has no image defects such as black spots and high durability and high image quality.

[Brief description of the drawings]

FIG. 1 is an X-ray diffraction spectrum of an imidazole perylene compound photosensitive member 1.

FIG. 2 is an X-ray diffraction spectrum of an imidazole perylene compound photosensitive member 6.

FIG. 3 is a diagram showing a layer structure of a photoreceptor according to the present invention.

FIG. 4 is a schematic configuration diagram of a recording apparatus that performs a method of the present invention.

FIG. 5 is a schematic diagram of a configuration of a developing device that performs the method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Conductive support 2 Carrier generating layer 3 Carrier transporting layer 4, 4 ', 4 "photosensitive layer 5 Intermediate layer 6 Carrier generating substance 7 Carrier transporting substance 10 Image carrier 11 Charger 13 Developing device 14 Exposure lamp before transfer 15 Transfer 16 Corona discharger for separation 17 Static eliminator 18 Cleaning device 19 Fixer 20 Developing sleeve 21 Magnetic roll 22 Thickness regulating blade 27 Bias power supply 28 Protection resistance

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-281769 (JP, A) JP-A-5-249719 (JP, A) JP-A-5-107789 (JP, A) JP-A-5-107789 119496 (JP, A) JP-A-4-276761 (JP, A) JP-A-5-6015 (JP, A) JP-A-54-145141 (JP, A) JP-A-62-127843 (JP, A) JP-A-49-76933 (JP, A) JP-A-4-204850 (JP, A) JP-A-5-80564 (JP, A) JP-A-5-281770 (JP, A) JP-A-5-257297 (JP, A) JP-A-2-124577 (JP, A) JP-A-2-97964 (JP, A) JP-A-4-264448 (JP, A) (58) Fields investigated (Int. Cl. ⁷⁾ , DB name) G03G 5/06

Claims (3)

(57) [Claims] 1. A conductive support having at least the following general formula [1] or general formula [2], and having a Bragg angle 2θ of 6.3 ± 0.2 ° in an X-ray diffraction spectrum with respect to Cu-Kα radiation,
It has peaks at 12.4 ± 0.2 °, 25.3 ± 0.2 ° and 27.1 ± 0.2 °, has the maximum peak intensity at 12.4 ± 0.2 °, and the half value of the peak is 0.65 or more, and is clear at 11.5 ± 0.2 ° have a crystalline form which has no such peak, and after sublimation purification,
After imparting a uniform charge on the photoreceptor provided with a photosensitive layer containing a perylene pigment that has been subjected to acid paste processing as a carrier generating substance, an electrostatic latent image is formed by exposure,
Subsequently, reversal development is performed. Embedded image 2. The carrier-generating substance has an average particle size of 0.5.
2. The image forming method according to claim 1, wherein the thickness is not more than μm. 3. The image forming apparatus according to claim 1, wherein the photosensitive layer is laminated on a support in the order of a carrier generating layer containing at least a carrier generating substance and a carrier transporting layer containing a carrier transporting substance. Method.