JPH0511470A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To provide the photosensitive body having the high sensitivity and stable light attenuation characteristics at the time of the repetitive use of the high-gamma photosensitive body and the good stationary characteristic of VH/VL between the surface potential VH of exposed parts and the surface potential VL of non-exposed parts, hence reproducibility of the fine lines of images. CONSTITUTION:A crystal mixture composed of titanyl phthalocyanine and vanadyl phthalocyanine is incorporated into the photoconductive layer of the photosensitive body having the max. value in the absolute value of the potential differentiation coefft. relating to a light quantity in the light attenuation (exposing) region of the potential fluctuation in the electrostatic charge-dark attenuation-light attenuation (exposing) of the electrophotographic sensitive body.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an electrophotographic photoreceptor,
In particular, the present invention relates to a photoconductor containing a mixed crystal of titanyl phthalocyanine and vanadyl phthalocyanine, having a high γ light attenuation property and suitable for digital image formation.

[0002]

2. Description of the Related Art Conventionally, as photoconductors used in electrophotography, so-called low γ photoconductors, in which light decay is slow in a light decay region of potential fluctuations from charging-dark decay-light decay (exposure), There is known a so-called high γ photoconductor in which there is a slow induction period in the early stage of image exposure and steep attenuation in the middle period and the latter period.

The reason why the high-γ photoconductor exhibits the above-mentioned characteristics has not been fully clarified, but
Carriers generated on the surface of the photosensitive substance (particularly photoconductive organic pigment) in the early stage of image exposure are temporarily trapped on the surface of the pigment to suppress light attenuation, and carrier trapping occurs in the middle and late stages of exposure. It becomes saturated, and as a result,
It is presumed that the surface potential shows an optical attenuation characteristic that drops almost linearly.

FIG. 1 shows the fluctuation of the surface potential over the regions of charging, dark decay and light decay of the photoconductor. The horizontal axis provided in common to the above three regions has different action contents in each region. The variable quantities are unified for convenience and are connected in a permutation by the action time quantity. FIG. 1A shows the characteristics of a low γ photoconductor, and FIG. 1B shows the characteristics of a high γ photoconductor.

In the high-γ photo-attenuating photoconductor, when the photo-attenuation curve in the photo-attenuation region is differentiated with the amount of light as an action variable (the intensity is constant and time is substituted), in the case of the photoconductor of positive charge as shown in FIG. In the initial stage, the differential coefficient shows a relatively small predetermined value including 0, then rapidly increases the negative value, reaches the minimum value, recovers again, and converges to 0. Therefore, when the absolute value of the differential coefficient is taken, a relatively small predetermined positive value including 0 passes through the maximum value and then converges to 0 again. The differential coefficient with respect to this curve is the gradient of the tangent line of the light attenuation curve a in FIG. Approximately, the absolute value of the difference coefficient when the surface potential of the photoconductor changes from V to V + ΔV when the light amount increases from a certain light amount I by ΔI; the value of | ΔV / ΔI | From a practical point of view, the absolute value of the above differential coefficient is substituted for | dV / dI | (Fig. 1
Then, ΔV takes a negative value). FIG. 2 shows the differential coefficient-light amount characteristics of the light attenuation curve obtained by using the above-mentioned approximate method. The curve A having the maximum value corresponds to the curve a in FIG. 1 (b). The curve A'corresponds to the light attenuation curve a'of FIG.

In recent years, in the field of electrophotography and the like, research and development of an image forming method employing a digital system, which enables easy image quality improvement, conversion, editing, and the like and enables high-quality image formation, has been actively conducted. In this image forming method, a high γ photoconductor is extremely useful. For example, laser, LED
Beams of an array, a liquid crystal shutter, and preferably a semiconductor laser are modulated by a digital image signal from a computer or a copy original, and dot-exposed on a uniformly charged photoreceptor to form a dot-shaped electrostatic latent image. When this is subjected to preferably reverse development with toner to form a dot-shaped image, dot exposure is usually performed with a very narrow pulse width of 50 to 100 μm at a brightness of 1 to 5 mW. With respect to the exposure with such a pulse width, the high-γ photoconductor has a short hem and is sharp in the potential distribution of the dot-shaped electrostatic latent image and the dot-shaped image density distribution, which is convenient for forming a digital image. (Japanese Patent Laid-Open Nos. 1-172853, 2-176768, etc.).

However, the photoreceptor having the characteristics of curve A in FIG. 2 (a), as shown in FIG. 2 (b) in the use of repetition, the laser beam exposure unit potential; V _L and the non-exposed portion potential; V _H
Are decreasing together. That is, the high γ photoconductor has a characteristic that the light attenuation is steep in the latter half of the exposure and has a high γ characteristic, but the light attenuation curve fluctuates in the process of repeated use, so that its effectiveness is impaired. . For example, there is a drawback in that the V _H greatly decreases after about 1000 cycles and the initial V _L is high, so that the developability becomes unstable such as fogging of image quality, skipped characters, and thickening of lines.

On the other hand, a mixed crystal of phthalocyanine has been reported in which not only a single phthalocyanine but also a plurality of phthalocyanines are used as a photoconductive substance to form a specific crystal arrangement. This mixed crystal has an advantage that it is possible to obtain characteristics different from those of a single phthalocyanine by forming the mixed crystal, unlike the mere mixing of a plurality of phthalocyanines. As an example of this mixed crystal of phthalocyanine, for example, JP-A-2-84661 discloses formation of a mixed crystal by co-evaporation of phthalocyanine in which two or more kinds of phthalocyanine are re-aggregated on a substrate through a gas phase state. However, the crystal-type mixed crystal of copper phthalocyanine and metal-free phthalocyanine and the mixed crystal of titanyl phthalocyanine and metal-free phthalocyanine disclosed therein have a problem of low sensitivity. The mixed crystal of titanyl phthalocyanine and vanadyl phthalocyanine by vapor deposition described in JP-A-2-70763 shows crystal forms corresponding to A-type and B-type of titanyl phthalocyanine. However, these crystal types are insufficient in terms of sensitivity. As described above, in order to satisfy the required characteristics in the mixed crystal as well, it is important to select the type and crystal form of the phthalocyanine constituting the mixed crystal. For that purpose, not only the material selection but also the crystal control technology for obtaining a specific crystal type is important, and the development of crystal conversion technology other than the currently known method of forming a mixed crystal is desired.

[0009]

OBJECT OF THE INVENTION The object of the present invention is to achieve high sensitivity and high γ
The photo-damping property of the photoconductor is stable during repeated use, and the ratio V _H / of the surface potential V _H of the exposed portion and the surface potential V _L of the non-exposed portion is
The object of the present invention is to provide a photoreceptor having good steadiness of V _L and thus reproducibility of fine image lines.

[0010]

The object of the present invention is to obtain the absolute value of the potential differential coefficient relating to the amount of light in the light attenuation (exposure) region of the potential fluctuation of electrification-dark decay-light decay (exposure) of the electrophotographic photosensitive member. It is achieved by an electrophotographic photosensitive member characterized by containing a mixed crystal of titanyl phthalocyanine and vanadyl phthalocyanine in a photoconductive layer having a maximum value.

Further, in an embodiment of the present invention, the mixed crystal of the titanyl phthalocyanine and vanadyl phthalocyanine is C.
Bragg angle 2 for uKα characteristic X-ray (wavelength 1.541Å)
It has a peak at 27.2 ± 0.2 ° of θ and an exothermic peak at 150 ° C to 400 ° C in a differential thermal analysis, or a Bragg angle 2θ of 9.5 ± 0.2 ° for CuKα characteristic X-ray (wavelength 1.541Å), It preferably has a peak at 27.2 ± 0.2 °.

Further, the object of the present invention is to maximize the absolute value of the potential differential coefficient with respect to the amount of light in the light attenuation (exposure) region of the potential fluctuation of electrification-dark decay-light decay (exposure) of the electrophotographic photosensitive member. The value of the Bragg angle 2θ for CuKα characteristic X-ray (wavelength 1.541Å) is 9.1 ±
It is also achieved by an electrophotographic photoreceptor characterized by containing a mixed crystal of titanyl phthalocyanine and vanadyl phthalocyanine having peaks at 0.2 ° and 27.2 ± 0.2 °.

In the present invention, a mixed crystal generally refers to a crystal when two or more kinds of substances are mixed to form a crystal in a uniform solution phase, which is as found in alums. It is known that mixed crystals are formed between metals having the same shape or similar crystal lattices, or metals having similar atomic radii. A similar tendency was observed for the mixed crystal of phthalocyanine having the crystal form of the present invention, and a mixed crystal having a structure relatively similar to that of titanyl phthalocyanine was apt to form a mixed crystal. Titanyl phthalocyanine is a W. H
iller et al. have performed crystal structure analysis (Z. Kr.
istallogr. , 159, 173 (1982)) whose structure is Ti = O
Has a structure protruding above the conjugate plane of the phthalocyanine ring. For this titanyl phthalocyanine, for example, it is difficult to obtain a mixed crystal of the crystal form of the present invention having a high crystal purity between a metal-free phthalocyanine having a planar structure and other crystals are mixed in the crystal form of the present invention. It is easy to cause performance deterioration. on the other hand,
The crystal structure of vanadyl phthalocyanine has also been analyzed (R. Ziolo et al., J. Chem. Soc. Da.
lton, 2300 (1980)) and T is what is titanyl phthalocyanine.
It has been reported that the i = O bond and the V = O bond have very similar steric structures, although there are slight differences. Therefore, vanadyl phthalocyanine is considered to have a favorable three-dimensional structure for forming a mixed crystal with titanyl phthalocyanine, and in fact, unlike some other phthalocyanines in vanadyl phthalocyanine, it has a mixed crystal form of the present invention. The crystals could be obtained.

The titanyl phthalocyanine used in the present invention is represented by the following general formula [I], and vanadyl phthalocyanine is represented by the general formula [II].

[0015]

[Chemical 1]

However, in the general formulas [I] and [II], X ¹ , X ² , X ³ and X ⁴ represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group or an aryloxy group, and k and l , M and n represent an integer of 0 to 4.

The X-ray diffraction spectrum is measured under the following conditions, and the peak here is a protrusion having a distinct acute angle different from noise.

X-ray tube Cu voltage 40.0 KV current 100 mA start angle 6.0 deg. Stop angle 35.0 deg. Step angle 0.02 deg. Measurement time 0.50 sec. The differential thermal analysis was carried out at a sample amount of 10 to 50 mg per measurement, and the temperature rising rate was 30 (° K / min).
As the state of the measurement sample, the powder crystal of the synthesized crystalline titanyl phthalocyanine-vanadyl phthalocyanine mixed crystal of the present invention was used. However, the same measurement was performed for the titanyl phthalocyanine-vanadyl phthalocyanine mixed crystal peeled from the photosensitive drum produced using this powder sample, and the same result was obtained when the comparison with the powder crystal was performed.

Further, the exothermic peaks observed at 150 to 400 ° C. by differential thermal analysis are unique to the crystalline phthalocyanine of the present invention among the various crystalline forms of phthalocyanine, and it is usually observed only by observing this exothermic peak. It is possible to determine whether or not the crystal type of the invention is a titanyl phthalocyanine-vanadyl phthalocyanine mixed crystal.

Further, the exothermic peak in the differential thermal analysis refers to a clear peak on the thermal differential curve, and the exothermic peak temperature indicates the temperature corresponding to the maximum point of the peak.

This exothermic peak found in the mixed crystal of the crystalline form of titanyl phthalocyanine and vanadyl phthalocyanine of the present invention represents a crystal transition point at which the crystalline form of the present invention is transformed into a thermally stable crystal. . Therefore, this value is a physical property value showing the thermal stability of phthalocyanine, and is closely related to the crystal arrangement. That is, it is shown that the crystals having different crystal transition points have different thermal behaviors. For example, as shown in the examples, the crystal transition point of the mixed crystal of titanyl phthalocyanine and vanadyl phthalocyanine of the present invention varies depending on the composition ratio of titanyl phthalocyanine and vanadyl phthalocyanine, but a mixed crystal having a plurality of different composition ratios is mixed. When the differential thermal analysis is performed by using the differential thermal analysis, the crystal transition point of the mixed crystal of each composition ratio is independently observed. What is observed when any crystalline vanadyl phthalocyanine is mixed with the crystalline titanyl phthalocyanine of the present invention is the crystal transition point of titanyl phthalocyanine, which is different from the mixed crystal with vanadyl phthalocyanine. This is because the components of titanyl phthalocyanine and vanadyl phthalocyanine in the mixed crystal form a uniform liquid phase in the solid state, which is essentially different from mixing.

The infrared absorption spectrum was measured under the following conditions.

Apparatus: Nicolet FT-IR 60SX Resolution: 0.25 cm ^-1 Measurement method: Diffuse reflection, KBr powder Various methods can be used to synthesize the titanyl phthalocyanine used in the present invention, but typically Can be synthesized according to the following reaction formula (1) or (2).

[0024]

[Chemical 2]

In the formula, R _{1 to} R ₄ represent a leaving group.

The vanadyl phthalocyanine used in the present invention is, like titanyl phthalocyanine, o-phthalonitrile, 1,3-diiminoisoindoline, vanadium pentoxide, and vanadium reagents typified by vanadium acetylacetone, 1-chloronaphthalene, etc. It can be obtained by reacting in an inert solvent.

The formation of a mixed crystal of titanyl phthalocyanine and vanadyl phthalocyanine obtained as described above was known only by the co-evaporation method as the prior art, but the detailed study by the present inventors was made. As a result, other than that, it is possible to form a mixed crystal by a method of uniformly precipitating in a solvent and then precipitating, or a method of applying a shearing force such as milling after mixing in a solid state. understood.

Specific examples include recrystallization, reprecipitation, acid paste treatment, and dry or wet milling. The crystal form of the present invention is obtained by establishing such a mixed crystal formation method. Came to. However, the method of forming a mixed crystal is not limited to these methods.

Next, a method for obtaining the crystalline titanyl phthalocyanine-vanadyl phthalocyanine mixed crystal used in the present invention will be exemplified. For example, a method of dissolving titanyl phthalocyanine and vanadyl phthalocyanine of any crystal form by ordinary acid paste treatment in concentrated sulfuric acid, pouring the sulfuric acid solution into water and collecting the precipitated crystals by filtration, or titanyl phthalocyanine of any crystal form. And vanadyl phthalocyanine are mixed, and the mixture is pulverized by mechanical force such as milling.
Amorphous crystals composed of vanadyl phthalocyanine are obtained. Here, when amorphization is performed by acid paste treatment, it is achieved under general conditions, and the weight ratio of concentrated sulfuric acid to phthalocyanine is not particularly limited, but is preferably about 5 to 200 times. Also, the amount of water used for draining concentrated sulfuric acid is usually 5 times by weight.
About 100 times is desirable. Further, the temperature at which phthalocyanine is dissolved in concentrated sulfuric acid is 5 ° C or lower, and the watering temperature is usually 0 ° C or higher.
50 ° C or less is desirable.

Next, the crystal form used in the present invention can be obtained by treating the amorphous crystal with a specific organic solvent. Examples of the organic solvent used include hydrocarbon solvents, aromatic solvents, halogen solvents, alcohols, ether solvents, ester solvents, organic acids, organic amines, heterocyclic compounds and the like, but if necessary. An acid such as sulfonic acid or trichloroacetic acid may be added. On the other hand, as the state of the amorphous crystal, either a wet paste state containing water or a dry state containing no water can be used, and this can be selected depending on the type and purpose of the organic solvent to be treated. . Further, in this solvent treatment, an operation such as heating or milling treatment can be performed as necessary. Further, as shown in Synthesis Example 6, the crystal once converted into the crystal form of the present invention by these methods can be further subjected to a crystal treatment as necessary such as a treatment with the above-mentioned organic solvent. However, the crystal conversion method is not necessarily limited to such a method.

The composition ratio of titanyl phthalocyanine and vanadyl phthalocyanine in the mixed crystal of titanyl phthalocyanine and vanadyl phthalocyanine of the present invention is not particularly limited as long as both phthalocyanines are present, but the abundance ratio of titanyl phthalocyanine is preferably 50% or more. More preferably, the abundance ratio of titanyl phthalocyanine is 80% or more. Furthermore, the abundance ratio of titanyl phthalocyanine is 90.
% Or more is most desirable. The abundance ratio as used herein refers to the weight ratio of contained titanyl phthalocyanine to the total weight.

In the electrophotographic photoreceptor of the present invention, a photoconductive substance may be used in combination with the above mixed crystal of titanyl phthalocyanine and vanadyl phthalocyanine. Other photoconductive materials include A, B, C, amorphous, and other types of crystal such as titanyl phthalocyanine and vanadyl phthalocyanine having a peak at 27.2 ° of Bragg angle 2θ represented by Y-type, and metal-free phthalocyanine. Various metal phthalocyanines typified by copper phthalocyanine, naphthalocyanines, other porphyrin derivatives, azo compounds, polycyclic quinone compounds typified by dibromoanthanthrone, eutectic complexes of pyrylium compounds and pyrylium compounds, squarylium compounds, etc. To be

Thus, it is possible to obtain a photoconductive layer containing a mixed crystal of titanyl phthalocyanine and vanadyl phthalocyanine (hereinafter referred to as mixed crystal phthalocyanine) which gives a light decay curve convenient for the high-sensitivity and high-γ photoreceptor of the present invention. .

The mixed crystal phthalocyanine itself according to the present invention should occupy 5 to 200 wt%, preferably 10 to 100 wt% of the resin in the photoconductive layer.

As the photoconductive layer of the photoconductor of the present invention, a coating in which a mixed crystal phthalocyanine and various other components for property adjustment are dispersed or dissolved in a binder resin is applied to the conductive support. As the binder resin, a resin that does not impair the high γ characteristic is selected. Specifically, in repeated use, the reduction of the induction period of the light decay curve is not caused, and the V
It is a resin that is convenient for maintaining the stability of _H / _VL , and a curable resin is selected in the present invention.

The curable resin is a resin which is cured by heat or light such as ultraviolet rays, and a practically suitable resin is a thermosetting resin, which includes melamine resin, polyester resin, silicone resin and urea. Resin, phenolic resin,
There are epoxy resin, alkyd resin, polyimide resin, urethane resin and the like. These may be used alone or as a mixture, or as a copolymer. Examples of preferable combinations (combined use) include silicone-melamine type,
Polyester-melamine type, methacrylic acid-melamine type,
Examples thereof include epoxy-melamine type or polyester-urea type, methacrylic acid-urea type, epoxy-urea and the like. Such a thermosetting resin is stable and has a strong binding force, and is advantageous in maintaining the durability of the conductive layer.

Next, the electrophotographic photoreceptor obtained by containing the mixed crystal phthalocyanine may be used in combination with a carrier transporting substance. Although various substances can be used as the carrier-transporting substance, typical examples include oxazole, oxadiazole, thiazole, thiadiazole,
Compounds having a nitrogen-containing heterocyclic nucleus represented by imidazole and the like, and condensed ring nuclei thereof, polyarylalkane compounds, pyrazoline compounds, hydrazone compounds, triarylamine compounds, styryl compounds, poly (bis) styryl Compounds, styryltriphenylamine compounds, β-phenylstyryltriphenylamine compounds, butadiene compounds, hexatriene compounds,
Examples thereof include carbazole compounds and condensed polycyclic compounds. Specific examples of these carrier-transporting substances include the carrier-transporting substances described in JP-A-61-107356. The ratio of the carrier transport material to the binder is preferably 10 to 200 wt%.

In forming the photoconductive layer, it is effective to apply a solution prepared by dispersing or dissolving the carrier-generating substance or the carrier-transporting substance alone or in a mixture with the binder and the additives. However, since the solubility of the carrier-generating substance is generally low, in such a case the carrier-generating substance is coated with a liquid in which fine particles are dispersed in a suitable dispersion medium using a dispersing device such as an ultrasonic disperser, a ball mill, a sand mill, or a homomixer. The method of doing is effective. In this case, the binder and additives are usually used by adding them to the dispersion liquid.

A wide variety of solvents or dispersion media can be used for forming the photoconductive layer. For example, butylamine, ethylenediamine, N, N-dimethylformamide, acetone, methyl ethyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, cyclohexanone, 4-methoxy-4-methyl-2-pentanone, tetrahydrofuran, dioxane, ethyl acetate, butyl acetate,
Examples thereof include -t-butyl acetate, methyl cellosolve, ethyl cellosolve, butyl cellosolve, ethylene glycol dimethyl ether, toluene, xylene, acetophenone, chloroform, dichloromethane, dichloroethane, trichloroethane, methanol, ethanol, propanol and butanol.

In addition to the above-mentioned curable resin, an arbitrary binder may be used in combination with the curable resin in the formation of the carrier transport layer of the laminated type photoreceptor. Further, an arbitrary binder can be used together as a binder for the sea part and the island part of the sea-island structure of the multi-layer type photoreceptor. Examples of such a binder include the following, but are not limited to these.

Polycarbonate resin Acrylic resin Methacrylic resin Polyvinyl chloride Polyvinylidene chloride Polystyrene Styrene-butadiene copolymer Polyvinyl acetate Polyvinyl formal Polyvinyl butyral Polyvinyl acetal Polyvinylcarbazole Styrene-alkyd resin Silicone resin Silicone-alkyd resin Silicone-butyral resin Polyester polyurethane Polyamide Epoxy resin Phenolic resin Vinylidene chloride-acrylonitrile copolymer Vinyl chloride-vinyl acetate copolymer Vinyl chloride-vinyl acetate-maleic anhydride copolymer Ratio of carrier transport material to binder is 10 ~ 500wt
%, Preferably 10 to 300 wt%.

The photoconductive layer may contain an electron accepting substance for the purpose of improving sensitivity, reducing residual potential, or reducing fatigue during repeated use. Examples of such an electron accepting substance include 9-fluorenone, 2,4,7-trinitro-9-fluorenone, 2,7-dinitrofluorenone,
2,6-dinitrofluorenone, 2,5-dinitrofluorenone, 2,4,5,7-tetranitrofluorenone, succinic anhydride,
Maleic anhydride, dibrom succinic anhydride, phthalic anhydride,
Tetrachlorophthalic anhydride, tetrabromophthalic anhydride, 3-nitrophthalic anhydride, 4-nitrophthalic anhydride, pyromellitic anhydride, meritic anhydride, tetracyanoethylene, tetracyanoquinodimethane, o-dinitrobenzene, m- Dinitrobenzene, 1,3,5-trinitrobenzene,
p-nitrobenzonitrile, picryl chloride, quinone chlorimide, chloranil, bromanil, dichlorodicyano-p-benzoquinone, anthraquinone, dinitroanthraquinone, 9-fluorenylidene malononitrile, polynitro-9-fluorenylidene malononitrile, picrin Acid, o-nitrobenzoic acid, p-nitrobenzoic acid, 3,5-dinitrobenzoic acid, pentafluorobenzoic acid, 5-nitrosalicylic acid, 3,5-dinitrosalicylic acid, phthalic acid, melitic acid and other electron affinity Large compounds can be mentioned. The addition ratio of the electron-accepting substance is preferably 0.01 to 200 with respect to 100 by weight of the carrier generating substance, and more preferably 0.1 to 200.
~ 100 is preferred.

The photoconductive layer may contain a deterioration inhibitor such as an antioxidant or a light stabilizer for the purpose of improving storage stability, durability and environmental resistance. Examples of the compound used for such purpose include chromanol derivatives such as tocopherol and etherified or esterified compounds thereof, polyarylalkane compounds, hydroquinone derivatives and mono- and dietherified compounds thereof, benzophenone derivatives, benzotriazole derivatives, thioether compounds. , Phosphonates, phosphites, phenylenediamine derivatives, phenol compounds, hindered phenol compounds, linear amine compounds, cyclic amine compounds, hindered amine compounds and the like are effective. Specific examples of particularly effective compounds include "IRGA
"NOX 1010", "IRGANOX 565" (manufactured by Ciba Geigy),
Examples include hindered phenolic compounds such as "Sumilyzer BHT" and "Sumilyzer MDP" (manufactured by Sumitomo Chemical Co., Ltd.), and hindered amine compounds such as "Sanol LS-2626" and "Sanol LS-622LD" (manufactured by Sankyo Co.). . Further, silicone oil may be present as a surface modifier. Further, an ammonium compound may be contained as a durability improver.

An intermediate layer may be provided between the photosensitive layer and the conductive support, and a surface protective layer may be provided on the surface of the photosensitive member.

As the binder used for the intermediate layer, the protective layer and the like, the above-mentioned curable resins, those mentioned for the carrier generating layer and the carrier transporting layer can be used, but in addition to them, nylon resin and ethylene-vinyl acetate Polymer, ethylene-vinyl acetate-maleic anhydride copolymer, ethylene
-Ethylene resins such as vinyl acetate-methacrylic acid copolymer, polyvinyl alcohol, and cellulose derivatives are effective. Further, a curable binder utilizing heat curing or chemical curing of melamine, epoxy, isocyanate or the like can be used.

A metal plate or a metal drum is used as the conductive support, and a conductive polymer, a conductive compound such as indium oxide, or a thin layer of a metal such as aluminum or palladium is applied, vapor-deposited, laminated or the like. Therefore, the one provided on a substrate such as paper or plastic film can be used.

Various forms of the layer structure of the photoconductor are known. The photoconductor of the present invention may take any of these forms, but it is preferable to use a laminated type or a single layer type function separation type photoconductor. In this case, normally, the configuration shown in FIG. 3A to FIG.

FIG. 3 shows an example of the photoconductor according to the present invention, in which 41 is a conductive support, 42 is an intermediate layer provided as necessary, and 43 is a photoconductive layer.

The photoconductive layer 43 is a coating solution prepared by mixing and dispersing the above-mentioned mixed crystal phthalocyanine, a binder resin, and if necessary, an antioxidant and an electron accepting substance in the form of fine particles using a solvent for the binder resin. Is prepared, and the coating solution is applied onto the intermediate layer 42, dried, and heat-cured to form.

The intermediate layer 42 functions as an adhesive layer or a barrier layer.

In the photoconductor of FIG. 3A, the photoconductive layer 43
No carrier transport material (CTM) needs to be contained in this case, but in this case, the photoconductor has a high γ optical attenuation characteristic as shown in FIGS. 1 (b) and 2 (a). CTM may be contained, but the upper limit is 2 with respect to 100 parts by weight of the binder resin.
It is recommended to use 0 part by weight.

The thickness of the photoconductive layer 43 is preferably about 5 to 100 μm, more preferably 5 to 50 μm.
If the film thickness of the photoconductive layer is too small, it is difficult to obtain high chargeability, and it is difficult to obtain high γ characteristics due to the avalanche phenomenon. On the other hand, if it is too large, high chargeability is imparted, but it has a light-attenuating property with a long hem, and it is difficult to obtain a dot-shaped image with high sharpness.

3 (b) and 3 (c) show another embodiment of the photoconductor, in which FIG. 3 (b) shows the charge transport layer 53 on the support 41 and the charge transport layer 53 as the upper layer. A photoconductive layer 43 having a laminated structure with the generating layer 52 as a lower layer is provided, and FIG.
And 52 are shown upside down (however, 55 is a mixed crystal phthalocyanine as a charge generating substance, and 56 is a carrier transporting substance).

In the case of this laminated structure, the thickness of the charge generation layer 52 is preferably 1 to 20 μm, particularly preferably 2 to 10 μm. If this thickness is too large, a residual potential is generated, and if it is too thin, on / off characteristics tend not to be exhibited.

A protective layer may be provided on the surface of the photoconductive layer shown in FIGS. 3 (a) and 3 (b).

Next, an example of an apparatus for carrying out the image forming method using the photoconductor of the present invention will be described with reference to FIGS. 4 (a) and 4 (b).

In FIG. 4A, 11 is a photoreceptor of the present invention which rotates in the direction of the arrow, 21 is a corona charger, and L
Is a dot-shaped image exposure light emitted from an optical system 26 such as a semiconductor laser, 15 is a developing device, 30 is a pre-transfer exposure lamp, 31
Is a fixing device, 32 is a pre-charge exposure lamp, 33 is a transfer electrode, 34 is a separation electrode, P is a transfer paper, 36 is a cleaning device (36a is a fur brush, 36b is a toner collecting roller, and 36c is a scraper). The developing device 15 may be of a monochrome or mono-color type, but in order to obtain a multicolor image, a developing device having yellow, magenta, cyan and black toners is provided.

Photoreceptor 11 is shown in FIG. 1 (b) and FIG. 2 (a) as A,
It has the high γ light attenuation characteristics shown in FIG. 2B, the surface is uniformly charged by the corona charger 21 composed of a scorotron band electrode, and then the laser optical system 26 forms dots according to the recording data. The image exposure light L is irradiated onto the photoconductor 11. After the latent image is formed in this manner, the latent image is developed by the developing device 15 containing the toner.

The photoreceptor 11 on which the toner image is formed is uniformly irradiated by the pre-transfer exposure lamp 30 if necessary, and then,
It is transferred onto the transfer paper P by the transfer pole 33. The transfer paper P is separated from the photoconductor 11 by the separation electrode 34 and fixed by the fixing device 31. The pre-transfer exposure lamp 30 may be omitted, and AC charge removal may be applied instead. On the other hand, the photoconductor 11 is cleaned by the cleaning device 36. Cleaning device 36
The fur brush 36a is kept in non-contact with the photoconductor 11 during image formation. When a toner image is formed on the photoconductor 11, the fur brush 36a comes into contact with the photoconductor 11 after the transfer and rotates in the direction of the arrow. The transfer residual toner is scraped off.

When the cleaning is completed, the fur brush 36a is separated from the photoconductor 11 again. An appropriate bias is applied to the toner collecting roller 36b while rotating in the direction of the arrow to collect toner and the like from the fur brush 36a. It is further scraped by the scraper 36c.

The laser optical system 26 described above is shown in FIG. In the figure, 37 is a semiconductor laser diode, 38 is a rotating polygon mirror, and 39 is an fθ lens.

In the above method, it is preferable to use a semiconductor laser such as GaAlAs as a dot exposure beam. That is, since the semiconductor laser can form a laser beam having an extremely narrow pulse width, it is possible to form a dot-shaped electrostatic latent image with high sharpness. Besides, a gas laser of He-Ne, He-Cd, Ar, or the like is used.

In the developing step, the dot-shaped electrostatic latent image formed on the photosensitive member by dot exposure with an exposure beam is subjected to one-component or two-component development containing fine particle toner having an average particle size of 1 to 20 μm. Develop with agent.

The contact reversal developing method may be adopted as the developing method, or the toner images of respective colors may be formed on the photoconductor in a superposed manner, and the toner images may be collectively transferred onto a transfer material and fixed to color the image. In the color image forming method for forming an image,
A method in which a high frequency AC bias is applied to the developing area to cause the toner to fly and non-contact reversal development may be employed (see Japanese Patent Application Laid-Open No. 58-184381).

In the above, even when the contact reversal development system is adopted, it is preferable to apply an AC bias to the developing area for development, and the action of the AC bias causes the toner to reach the latent image surface of the photoconductor. There is an advantage that the latent image surface is uniformly and sharply developed by being pressed and developed from the vertical direction.

[0066]

【Example】

: Synthesis of titanyl phthalocyanine: 2,3-diiminoisoindoline (29.2 g), o-dichlorobenzene (200 ml) and titanium tetrabutoxide side (20.4 g) were mixed and refluxed under a nitrogen stream for 3 hours. After allowing to cool and returning to room temperature, the precipitated crystals were collected by filtration, washed with o-dichlorobenzene and further washed with methanol. Further, the obtained crystals were washed with stirring in a 2% hydrochloric acid aqueous solution at room temperature several times, and further washed with deionized water several times. Then, it was washed with methanol and dried to obtain 24.2 g of blue-violet titanyl phthalocyanine crystal.

Synthesis of vanadyl phthalocyanine: 29.2 g of 1,3-diiminoisoindoline and 200 ml of o-dichlorobenzene
And 8 g of vanadyl acetylacetonate were mixed and refluxed under a nitrogen stream for 5 hours. Then, the mixture was allowed to cool to room temperature and then the precipitated crystals were collected by filtration, washed with o-dichlorobenzene, and further washed with methanol. Further, the obtained crystals were washed with stirring in a 2% hydrochloric acid aqueous solution at room temperature several times, and further washed with deionized water several times. After drying, this crystal was recrystallized from 1-chloronaphthalene to obtain 18.9 g of purple vanadyl phthalocyanine crystal.

Synthesis of Mixed Crystals: Synthesis Example 1 4 g of titanyl phthalocyanine and 1 g of vanadyl phthalocyanine were dissolved in 250 g of 96% sulfuric acid under ice cooling, and this sulfuric acid solution was poured into 5 l of water to form an amorphous wet paste. It was collected by filtration.

Further, 50 g of this wet paste and o-dichlorobenzene were mixed and stirred at a temperature of 50 ° C. for 2 hours. The reaction solution was diluted with methanol and filtered, and the obtained crystals were washed with methanol several times to obtain blue crystals. This crystal has a Bragg angle of 2θ of 9.5 ° and 27.2 as shown in Fig. 5.
It was found to be the mixed crystal phthalocyanine of the present invention having a peak at ° and an exothermic peak at 237 ° C by differential thermal analysis. Furthermore, this crystal has an infrared absorption spectrum shown in FIG.
In particular, the crystal of the present invention exhibits a characteristic absorption in the region of 950 to 1050 cm ^-1 . FIG. 20 particularly shows the absorption spectrum in this region. Unlike the comparative synthesis example (1), absorption characteristic of the crystal of the present invention is observed at 994 cm ⁻¹ , which is considered to be absorption derived from the V═O bond of vanadyl phthalocyanine. It also shows absorption at 961 cm ^-1 , which is similar to that of Comparative Synthesis Example (3) in that Ti =
Considered O absorption. As described above, the mixed crystal phthalocyanine of the present invention shows absorption in which two kinds of phthalocyanines are independently derived from the crystal form of the present invention, and supports the existence of these two kinds of phthalocyanines.

Synthesis Example 2 Blue crystals were obtained in the same manner as in Synthesis Example 1 except that 2.5 g of titanyl phthalocyanine and 2.5 g of vanadyl phthalocyanine were used in Synthesis Example 1. As shown in FIG. 6, this crystal had peaks at Bragg angles 2θ of 9.5 ° and 27.2 °, and also showed an exothermic peak at 228 ° C. in differential thermal analysis. Furthermore, in the infrared absorption spectrum, as shown in Fig. 21, it is 994 cm.
Absorption at ^-1 and 961 cm ^-1 .

Synthesis Example 3 Blue crystals were obtained in the same manner as in Synthesis Example 1, except that 1 g of titanyl phthalocyanine and 4 g of vanadyl phthalocyanine were used in Synthesis Example 1. As shown in FIG. 7, this crystal had peaks at Bragg angles 2θ of 9.5 ° and 27.2 °, and also showed an exothermic peak at 219 ° C. in differential thermal analysis. Furthermore, in the infrared absorption spectrum, as shown in Fig. 22, 995 cm ^-1
And showed absorption at 961 cm ^-1 .

Synthesis Example 4 Blue crystals were obtained in the same manner as in Synthesis Example 1 except that 0.5 g of titanyl phthalocyanine and 4.5 g of vanadyl phthalocyanine were used in Synthesis Example 1. As shown in FIG. 8, this crystal had peaks at Bragg angles 2θ of 9.5 ° and 27.2 °, and also showed an exothermic peak at 216 ° C. in differential thermal analysis. Furthermore, in the infrared absorption spectrum, as shown in Fig. 23, 1003 cm ^-1
And absorption at 965 cm ^-1 and 961 cm ^-1 .

Synthesis Example 5 Blue crystals were obtained in the same manner as in Synthesis Example 1 except that 4.75 g of titanyl phthalocyanine and 0.25 g of vanadyl phthalocyanine were used in Synthesis Example 1. As shown in FIG. 9, this crystal had peaks at Bragg angles 2θ of 9.5 ° and 27.2 °, and also showed an exothermic peak at 247 ° C in differential thermal analysis.

Synthesis Example 6 The mixed crystal phthalocyanine of FIG. 6 obtained in Synthesis Example 2 was milled in THF and further washed with methanol to obtain Bragg angles 2θ of 9.1 ° and 27.2 ° as shown in FIG. A titanyl phthalocyanine having a peak was obtained. An exothermic peak of this titanyl phthalocyanine was observed at 300 ° C. in the differential thermal analysis. Further, in the infrared absorption spectrum, as shown in FIG. 21, absorption was shown at 994 cm ⁻¹ and 961 cm ⁻¹ .

Synthesis Example 7 The mixed crystal phthalocyanine of FIG. 7 obtained in Synthesis Example 3 was milled in THF and further washed with methanol to obtain Bragg angles 2θ of 9.1 ° and 27.2 ° as shown in FIG. A titanyl phthalocyanine having a peak was obtained. An exothermic peak of this titanyl phthalocyanine was observed at 248 ° C. in the differential thermal analysis.

Synthesis Example 8 A mixed crystal of titanyl phthalocyanine and vanadyl phthalocyanine was prepared in the same manner as in Synthesis Example 1 except that 0.5 g of tetra-t-butyl titanyl phthalocyanine was added in addition to 4 g of titanyl phthalocyanine and 1 g of vanadyl phthalocyanine in Synthesis Example 1. Obtained. This crystal has a Bragg angle of 2 as shown in FIG.
There were peaks at 9.5 ° and 27.2 ° in θ, but the peaks were broad and no clear exothermic peak was observed in the differential thermal analysis.

Synthesis Example 9 The mixed crystal phthalocyanine obtained in Synthesis Example 8 was converted to a mixed crystal phthalocyanine having peaks at 9.1 ° and 27.2 ° of Bragg angles 2θ by milling. No clear exothermic peak was observed in the mixed crystal in the differential thermal analysis.

Synthetic Example 10 4 g of titanyl phthalocyanine and 1 g of vanadyl phthalocyanine were mixed and thoroughly mixed in a mortar, and then pulverized in an automatic mortar until no clear peak was observed in X-ray diffraction to give amorphous titanyl phthalocyanine. A composition consisting of vanadyl phthalocyanine was obtained. After washing this with methanol, it was thoroughly stirred in 50 l of water. Then add 50 g of o-dichlorobenzene and add 2 at 50 ℃.
Stir for hours. This solution was diluted with methanol and filtered,
Further, the obtained crystals were washed with methanol several times to obtain blue crystals. This crystal had peaks at Bragg angles 2θ of 9.5 ° and 27.2 °, and an exothermic peak was observed at 237 ° C in the differential thermal analysis.

Comparative Synthesis Example (1) As the vanadyl phthalocyanine, unrecrystallized crude crystal obtained by the reaction of 1,3-diiminoisoindoline and vanadyl acetylacetonate was used, and 5 g of this crude crystal was used.
Was dissolved in 250 g of 96% sulfuric acid under ice cooling in the same manner as in Synthesis Example 1, the sulfuric acid solution was poured into 5 l of water, and the wet paste in an amorphous state deposited was collected by filtration.

Further, this wet paste was mixed with 50 g of o-dichlorobenzene and stirred at a temperature of 50 ° C. for 2 hours. The reaction solution was diluted with methanol and filtered, and the obtained crystals were washed with methanol several times to obtain blue crystals. This crystal has a Bragg angle 2θ of 7.5 °, 9.5 °, as shown in FIG.
Although it had peaks at 27.2 ° and 28.6 °, no distinct exothermic peak was observed in the differential thermal analysis. Further, in the infrared absorption spectrum, absorption was shown at 1003 cm ⁻¹ as shown in FIG.

Comparative Synthesis Example (2) A blue crystal was obtained in the same manner as in Synthesis Example 1 except that vanadyl phthalocyanine recrystallized and refined with 1-chloronaphthalene was used as vanadyl phthalocyanine in Comparative Synthesis Example (1). This crystal has a Bragg angle of 2θ as shown in Fig. 14.
It had peaks at 7.5 ° and 28.6 °, and no distinct exothermic peak was observed in differential thermal analysis. In addition, the infrared absorption spectrum showed absorption at 1003 cm ^-1 .

Comparative Synthesis Example (3) Blue crystals were obtained in the same manner as in Comparative Synthesis Example (1) except that the titanyl phthalocyanine obtained in the above Synthesis Example was used instead of vanadyl phthalocyanine in Comparative Synthesis Example (1). This crystal has a Bragg angle of 2θ as shown in Fig. 15.
It has peaks at 9.5 ° and 27.2 ° and is 2 in differential thermal analysis.
It was titanyl phthalocyanine having an exothermic peak at 55 ° C. Furthermore, this crystal shows
As shown in 25, absorption was exhibited at 961 cm ^-1 .

Comparative Synthesis Example (4) The titanyl phthalocyanine obtained in Comparative Synthesis Example (3) was milled in THF and further washed with methanol to obtain blue crystals. As shown in FIG. 16, this crystal was titanyl phthalocyanine having peaks at Bragg angles 2θ of 9.0 ° and 27.2 ° and having an exothermic peak at 361 ° C. in differential thermal analysis.

Comparative Synthesis Example (5) The powder obtained by sufficiently drying the wet paste obtained in Synthesis Example 1 was recrystallized with 1-chloronaphthalene. The obtained crystal has a Bragg angle of 2θ as shown in FIG.
It is an A-type crystal with peaks at 9.2 °, 10.5 °, 13.1 °, 15.0 °, 26.2 °, and 27.1 °.
No exothermic peak was shown in the region below 00 ° C.

Comparative Synthesis Example (6) 2 g of powder obtained by sufficiently drying the wet paste obtained in Synthesis Example 2 was heated to reflux in 150 ml of 1,1,2,2-tetrachloroethane, and as shown in FIG. With a Bragg angle of 2θ
A B-type crystal having peaks at 7.5 ° and 28.6 ° was obtained. When a differential thermal analysis of this crystal was performed, no clear exothermic peak was observed in the region of 150 ° C to 400 ° C.

Comparative Synthetic Example (7) 2.5 g of the titanyl phthalocyanine obtained in Comparative Synthetic Example (3) and 2.5 g of vanadyl phthalocyanine obtained in Comparative Synthetic Example 1 were sufficiently homogeneous using a mortar under the condition that crystal transition did not occur. Mixed in. When a differential thermal analysis of this mixture was carried out, an exothermic peak was observed at 255 ° C., which was in agreement with the value of titanyl phthalocyanine of Comparative Synthesis Example (3). In the infrared absorption spectrum, 961 cm ^-1 and 100
A peak was shown at 3 cm ^-1 , which was in agreement with the values of titanyl phthalocyanine of Comparative Synthesis Example (3) and vanadyl phthalocyanine of Comparative Synthesis Example (1). However, the peak at 994 cm ^-1 as seen in Synthesis Example 2 was not observed.

Comparative Synthetic Example (8) 2.5 g of the titanyl phthalocyanine obtained in Comparative Synthetic Example (3) and vanadyl phthalocyanine which was made amorphous by acid paste treatment were mixed sufficiently uniformly using a mortar under the condition that crystal transition does not occur. did.
When differential thermal analysis of this mixture was carried out, exothermic peaks were observed at 255 ° C. and 240 ° C., and these values were respectively in agreement with those of the titanyl phthalocyanine of Comparative Synthesis Example (3) and vanadyl phthalocyanine amorphized. In the infrared absorption spectrum showed a peak at 961cm ^-1 and 998 ^-1 as shown in FIG. 26, it matches the value of the titanyl phthalocyanine and amorphized vanadyl phthalocyanine, respectively Comparative Synthesis Example (3). However, the peak at 994 cm ^-1 as seen in Synthesis Example 2 was not observed.

Example 1 4 parts of the mixed crystal phthalocyanine of the present invention obtained in Synthesis Example 1,
8 parts of polyester resin (“ALMATEX P-645” manufactured by Mitsui Toatsu Chemical Co., Ltd.) as a binder resin, melamine resin (“Kobanma 1R” manufactured by Mitsui Toatsu Chemical Co., Ltd.) 2
Parts, and 90 parts of cyclohexane as a dispersion medium were dispersed by a sand grinder to obtain a dispersion liquid.

This dispersion was dip-coated on a direct aluminum drum of 150 mm and heat-dried at 120 ° C. for 1 hour to give a film thickness of 1
A photoconductive layer having a thickness of 5 μm is formed to obtain a photoreceptor of the present invention, which will be referred to as Sample 1.

Example 2 A photoreceptor was prepared in the same manner as in Example 1 except that the mixed crystal phthalocyanine obtained in Synthesis Example 1 was used instead of the mixed crystal phthalocyanine obtained in Synthesis Example 1. It was created. This is sample 2.

Example 3 A photoreceptor was prepared in the same manner as in Example 1 except that the mixed crystal phthalocyanine obtained in Synthesis Example 1 was used instead of the mixed crystal phthalocyanine obtained in Synthesis Example 1. It was created. This is sample 3.

Example 4 A photoreceptor was prepared in the same manner as in Example 1 except that the mixed crystal phthalocyanine obtained in Synthesis Example 1 was used instead of the mixed crystal phthalocyanine obtained in Synthesis Example 1. It was created. This is sample 4.

Example 5 A photoreceptor was prepared in the same manner as in Example 1 except that the mixed crystal phthalocyanine obtained in Synthesis Example 1 was used instead of the mixed crystal phthalocyanine obtained in Synthesis Example 1. It was created. This is sample 5.

Example 6 A photoreceptor was prepared in the same manner as in Example 1 except that the mixed crystal phthalocyanine obtained in Synthesis Example 1 was used instead of the mixed crystal phthalocyanine obtained in Synthesis Example 1. It was created. This is sample 6.

Example 7 A photoreceptor was prepared in the same manner as in Example 1 except that the mixed crystal phthalocyanine obtained in Synthesis Example 1 was used instead of the mixed crystal phthalocyanine obtained in Synthesis Example 1. It was created. This is sample 7.

Example 8 A photoreceptor was prepared in the same manner as in Example 1 except that the mixed crystal phthalocyanine obtained in Synthesis Example 1 was used instead of the mixed crystal phthalocyanine obtained in Synthesis Example 1. It was created. This is sample 8.

Example 9 A photoreceptor was prepared in the same manner as in Example 1 except that the mixed crystal phthalocyanine obtained in Synthesis Example 1 was used instead of the mixed crystal phthalocyanine obtained in Synthesis Example 1. It was created. This is sample 9.

Example 10 A photoreceptor was prepared in the same manner as in Example 1 except that the mixed crystal phthalocyanine obtained in Synthesis Example 1 was used instead of the mixed crystal phthalocyanine obtained in Synthesis Example 1. It was created. This is sample 10.

Comparative Example (1) In the same manner as in Example 1 except that the vanadyl phthalocyanine obtained in Comparative Synthesis Example (1) was used in place of the mixed crystal phthalocyanine obtained in Synthesis Example 1 in Example 1. A photoconductor was created. This is designated as Comparative Sample (1).

Comparative Example (2) In the same manner as in Example 1 except that the mixed crystal phthalocyanine obtained in Synthesis Example 1 in Example 1 was replaced by the vanadyl phthalocyanine obtained in Comparative Synthesis Example (2). A photoconductor was created. This is designated as Comparative Sample (2).

Comparative Example (3) In the same manner as in Example 1 except that the mixed crystal phthalocyanine obtained in Synthesis Example 1 in Example 1 was replaced by the titanyl phthalocyanine obtained in Comparative Synthesis Example (3). A photoconductor was created. This is designated as Comparative Sample (3).

Comparative Example (4) In the same manner as in Example 10 except that the mixed crystal phthalocyanine obtained in Synthesis Example 1 in Example 10 was replaced by the titanyl phthalocyanine obtained in Comparative Synthesis Example (4). A photoconductor was created. This is designated as Comparative Sample (4).

Comparative Example (5) Instead of using the mixed crystal phthalocyanine obtained in Synthesis Example 1 in Example 1, the mixed crystal A-type crystal of titanyl phthalocyanine and vanadyl phthalocyanine obtained in Comparative Synthesis Example (5) was used. A photoconductor was prepared in the same manner as in Example 1 except that it was used. This is designated as Comparative Sample (5).

Comparative Example (6) Instead of using the mixed crystal phthalocyanine obtained in Synthesis Example 1 in Example 1, the B-type crystal of the mixed crystal of titanyl phthalocyanine and vanadyl phthalocyanine obtained in Comparative Synthesis Example (6) was used. A photoconductor was prepared in the same manner as in Example 1 except that it was used. This is designated as Comparative Sample (6).

Comparative Example (7) Example except that the mixed crystal phthalocyanine obtained in Synthesis Example 1 in Example 1 was used instead of the mixture of titanyl phthalocyanine and vanadyl phthalocyanine obtained in Comparative Synthesis Example (7). A photoconductor was prepared in the same manner as in 1. This is designated as Comparative Sample (7).

Comparative Example (8) Example except that the mixed crystal phthalocyanine obtained in Synthesis Example 1 in Example 1 was replaced by the mixture of titanyl phthalocyanine and vanadyl phthalocyanine obtained in Comparative Synthesis Example (8). A photoconductor was prepared in the same manner as in 1. This is designated as Comparative Sample (8).

(Evaluation) “Konica 8010” was used for each photoreceptor described above.
Attached to (Konica Co., Ltd.) modified machine red developing device laser on the potential V _L at position start the first cycle measured laser-off potential V _H and the 10,000 cycle at each surface potentiometer (AA-2404 (Manufactured by Ando Electric Co., Ltd.). In addition, a 2-dot thin line was imaged in black, and this was measured with a microdensitometer (manufactured by Konica Corp.) to determine the peak density.
The line width of 1/2 was obtained and the image quality was evaluated.

The results are shown in Tables 1 and 2.

Table 1: Potential change: Sample No. Start potential 10,000 cycle potential △ V1 / 10,000 _VH / _VL (V) _VH / _VL (V) △ _VH / △ _VL (V) Implementation Example 1 600/50 590/45 -10 / -5 〃 2 600/55 590/50 -10 / -5 〃 3 600/55 595/52 -5 / -3 〃 4 600/60 590/55 -10 / -5 〃 5 600/50 590/45 -10 / -5 〃 6 600/50 590/45 -10 / -5 〃 7 600/65 595/62 -5 / -3 〃 8 600/55 590 / 50- 10 / -5 〃 9 600/55 590/50 -10 / -5 〃 10 600/50 590/45 -10 / -5 Comparative example (1) 600/150 450/100 −150 / −50 〃 (2) 600/200 570/180 −30 / −20 〃 (3) 600/50 500/20 −100 / −30 〃 (4) 600/70 470/30 −130 / −40 〃 (5) 600/100 470 / 60 −130 / −40〃 (6) 600/90 430/30 −170 / −60〃 (7) 600/100 500/70 −100 / −30〃 (8) 600/100 500/70 −100 / − 30 Table 2: 2-dot thin line width: Trial No Start time 10,000 cycles 10,000 cycles (μm) (μm) Variation range (μm) Example-1 240 250 10 〃 2 230 240 10 〃 3 230 240 10 〃 4 220 230 10 〃 5 240 250 10 〃 6 240 250 10 〃 7 210 220 10 〃 8 230 240 10 〃 9 230 240 10 〃 10 240 250 10 Comparative Example (1) 170 320 150 〃 (2) 150 220 70 〃 (3) 240 350 110 〃 (4 ) 220 350 130 〃 (5) 200 330 130 〃 (6) 210 370 160 〃 (7) 200 310 110 〃 (8) 200 310 110 As is clear from Tables 1 and 2, in this example, the initial sensitivity was V _L is good, and V _H , V _L, and the line width are stable during repetition, but the fluctuations are large in the comparative example.

[0110]

EFFECT OF THE INVENTION A photosensitive member having a high sensitivity and a high γ, and a stable surface potential repetitively and fine line reproducibility can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing surface potential fluctuations in a region of charging-dark decay-light decay of a photoconductor.

FIG. 2 is a diagram showing a differential coefficient of an optical attenuation curve and a potential drop during repeated use.

FIG. 3 is a cross-sectional view of a layer configuration example of a photoconductor according to the present invention.

FIG. 4 is an explanatory diagram of an example of an image forming apparatus using the photoconductor of the present invention.

5 is an X-ray diffraction pattern of the mixed crystal phthalocyanine obtained in Synthesis Example 1. FIG.

FIG. 6 is an X-ray diffraction diagram of the mixed crystal phthalocyanine obtained in Synthesis Example 2.

7 is an X-ray diffraction pattern of the mixed crystal phthalocyanine obtained in Synthesis Example 3. FIG.

FIG. 8 is an X-ray diffraction diagram of the mixed crystal phthalocyanine obtained in Synthesis Example 4.

FIG. 9 is an X-ray diffraction diagram of the mixed crystal phthalocyanine obtained in Synthesis Example 5.

FIG. 10: X of the mixed crystal phthalocyanine obtained in Synthesis Example 6
Line diffraction diagram.

FIG. 11: X of the mixed crystal phthalocyanine obtained in Synthesis Example 7.
Line diffraction diagram.

FIG. 12: X of mixed crystal phthalocyanine obtained in Synthesis Example 8
Line diffraction diagram.

FIG. 13 is an X-ray diffraction diagram of the mixed crystal phthalocyanine obtained in Comparative Synthesis Example (1).

FIG. 14 is an X-ray diffraction diagram of the mixed crystal phthalocyanine obtained in Comparative Synthesis Example (2).

FIG. 15 is an X-ray diffraction diagram of the mixed crystal phthalocyanine obtained in Comparative Synthesis Example (3).

FIG. 16 is an X-ray diffraction diagram of the mixed crystal phthalocyanine obtained in Comparative Synthesis Example (4).

FIG. 17 is an X-ray diffraction diagram of A-type mixed crystal phthalocyanine obtained in Comparative Synthesis Example (5).

FIG. 18 is an X-ray diffraction diagram of B-type mixed crystal phthalocyanine obtained in Comparative Synthesis Example (6).

FIG. 19 is an infrared absorption spectrum of the mixed crystal phthalocyanine obtained in Synthesis Example 1.

20 is a partial cutaway view of an infrared absorption spectrum of the mixed crystal phthalocyanine obtained in Synthesis Example 1. FIG.

FIG. 21 is an infrared absorption spectrum of the mixed crystal phthalocyanine obtained in Synthesis Example 2.

22 is an infrared absorption spectrum of the mixed crystal phthalocyanine obtained in Synthesis Example 3. FIG.

23 is an infrared absorption spectrum of the mixed crystal phthalocyanine obtained in Synthesis Example 4. FIG.

FIG. 24 is an infrared absorption spectrum of the mixed crystal phthalocyanine obtained in Comparative Example (1).

FIG. 25 is an infrared absorption spectrum of the mixed crystal phthalocyanine obtained in Comparative Example (2).

FIG. 26 is an infrared absorption spectrum of the mixture of titanyl phthalocyanine and amorphous vanadyl phthalocyanine obtained in Comparative Example (8).

[Explanation of symbols]

a high γ light attenuation curve a ′ low γ light attenuation curve A a derivative curve A ′ a ′ derivative curve _VL laser-on potential V _H laser-off potential 41 conductive support 42 intermediate layer 43 photoconductive layer

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kazumasa Watanabe             Konica Stock Market, 1 Sakura-cho, Hino City, Tokyo             Company (72) Inventor Akihiko Itami             Konica Stock Market, 1 Sakura-cho, Hino City, Tokyo             Company

Claims (4)

[Claims] 1. A photoreceptor light having a maximum absolute value of a potential differential coefficient with respect to the amount of light in the light decay (exposure) region of the potential fluctuation of electrification-dark decay-light decay (exposure) of the electrophotographic photoreceptor. An electrophotographic photoreceptor comprising a conductive layer containing a mixed crystal of titanyl phthalocyanine and vanadyl phthalocyanine. 2. A mixed crystal of titanyl phthalocyanine and vanadyl phthalocyanine is CuKα characteristic X-ray (wavelength 1.541Å).
2. The electrophotographic photosensitive member according to claim 1, having a peak at 27.2 ± 0.2 ° of Bragg angle 2θ with respect to, and having an exothermic peak at 150 ° C. to 400 ° C. in the differential thermal analysis. 3. A mixed crystal of titanyl phthalocyanine and vanadyl phthalocyanine is CuKα characteristic X-ray (wavelength 1.541Å).
2. The electrophotographic photosensitive member according to claim 1, having peaks at 9.5 ± 0.2 ° and 27.2 ± 0.2 ° of the Bragg angle 2θ with respect to. 4. A photoreceptor light having a maximum absolute value of a potential differential coefficient with respect to a light quantity in the light decay (exposure) region of the potential fluctuation over charging-dark decay-light decay (exposure) of the electrophotographic photoreceptor. CuKα characteristic X-ray (wavelength 1.541
Å) Bragg angle 2θ of 9.1 ± 0.2 °, 27.2 ± 0.2
An electrophotographic photosensitive member comprising a mixed crystal of titanyl phthalocyanine and vanadyl phthalocyanine having a peak at °.