JPH04159557A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain sufficient sensitivity even in a long wavelength by incorporating a specified fluorene compound in a photosensitive layer. CONSTITUTION:The photosensitive layer contains monocrystalline oxytitanium- phthalocyanine having intense peaks in the Bragg angle 2theta + or - 0.2 deg.; 9.0 deg., 14.2 deg., 23.9 deg. and 27.1 deg. in the X-ray diffraction using CuKalpha, and the fluorene compound represented by formula I in which each of R<1> and R<2> is H, alkyl, aralkyl, or aryl; each of R<3> - R<6> is aryl, thus permitting the obtained electrophotographic sensitive body to be high in sensitivity in the long wavelength region like laser diode beams, to exhibit stable image characteristics and superior potential stability.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an electrophotographic photoreceptor having improved characteristics, and more particularly, the present invention relates to an electrophotographic photoreceptor having improved characteristics, and more particularly, to The present invention relates to an electrophotographic photoreceptor having:

[Conventional technology]

Conventionally, inorganic photoreceptors having a photosensitive layer containing selenium, cadmium sulfide, zinc oxide, etc. as main components have been widely used as electrophotographic photoreceptors. These are not necessarily satisfactory in terms of thermal stability, moisture resistance, durability, etc.
In particular, selenium and cadmium sulfide have limitations in production and handling due to their toxicity. On the other hand, organic photoreceptors having a photosensitive layer containing an organic photoconductive compound as a main component have attracted attention in recent years because they have many advantages such as overcoming the above-mentioned drawbacks of inorganic photoreceptors.

Such organic photoreceptors include photoconductive polymers typified by poly-N-vinylcarbazole and 2.
Electrophotographic photoreceptors having a photosensitive layer mainly composed of a charge transfer complex formed from a Lewis acid such as 4,7-dolinitro-9-fluorenone have already been put to practical use. However, this photoreceptor is not necessarily satisfactory in sensitivity and durability.

On the other hand, a so-called functionally separated electrophotographic photoreceptor, in which the charge generation function and the charge transport function are divided into separate substances, is
This resulted in significant improvements in sensitivity and durability, which were considered to be shortcomings of conventional organic photoreceptors. This functionally separated photoreceptor has a wide range of materials to choose from for charge-generating substances and charge-transporting substances.
This method has the advantage that an electrophotographic photoreceptor having arbitrary characteristics can be produced relatively easily.

In recent years, electrophotographic photoreceptors have been rapidly used not only in copying machines but also in non-impact printers that apply electrophotographic technology. These are laser beam printers that mainly use laser light as a light source.
A semiconductor laser is used as the light source due to cost and device size considerations.

Currently, the semiconductor lasers mainly used have a long oscillation wavelength of 790±20 nm, and efforts have been made to develop electrophotographic photoreceptors that have sufficient sensitivity to light at these long wavelengths.

Sensitivity on the long wavelength side varies depending on the type of charge-generating material, and many charge-generating materials are being studied.

Typical charge generating materials include phthalocyanine pigments, azo pigments, cyanine dyes, azulene dyes, and squarylium dyes.

On the other hand, as charge-generating materials sensitive to long-wavelength light, research has recently been conducted on metal phthalocyanines or metal-free phthalocyanines such as aluminum lophthalocyanine, chloroindium phthalocyanine, oxyvanadyl phthalocyanine, chlorogallium phthalocyanine, magnesium phthalocyanine, and oxytitanium phthalocyanine. Many things have been done.

Among these, many phthalocyanine compounds are known to have polymorphisms; for example, metal-free phthalocyanine has an α-type,
There are β-type, γ-type, δ-type, ε-type, X-type, τ-type, etc., and α-type, β-type, γ-type, δ-type, ε-type, X-type, etc. are generally known for copper phthalocyanine.

It is also generally known that differences in crystal form greatly affect electrophotographic properties (sensitivity, potential stability during durability, etc.) and coating properties when made into a coating.

Oxytitanium phthalocyanine, which is particularly sensitive to long-wavelength light, has polymorphisms as well as other phthalocyanines, such as metal-free phthalocyanine and copper phthalocyanine, as described above. For example, JP-A-59-495
Publication No. 44 (USP 4,444,861), JP-A-59
-166959, JP 61-239248 (USP 4,728,592), JP 62-670
Publication No. 94 (USP 4,664,997), JP-A-63
-366, JP 63-116158, JP 63-198067, and JP 64-17
No. 066 reports oxytitanium phthalocyanine having different crystal forms.

However, these oxytitanyl phthalocyanines have problems in actual use, such as insufficient sensitivity, poor potential stability during repeated use, poor charging ability, and image deterioration due to changes in the usage environment. There are a few things that I'm disappointed in, and I still haven't found anything that I'm fully satisfied with.

By the way, in general, in photoreceptors, a charge transporting substance that is effective for a certain charge-generating substance is not necessarily effective for other charge-generating substances, and conversely, a charge-transporting substance that is effective for a certain charge-generating substance is not necessarily effective for other charge-generating substances. Certain charge generating materials are not necessarily effective against other charge transporting materials. That is, there is always a preferable combination of charge generating substances and charge transporting substances that receive and transfer charges.

An inappropriate combination will cause many problems such as a decrease in sensitivity and an increase in residual potential, deterioration in potential stability during repeated use, and a decrease in charging ability.

Therefore, the combination of a charge-generating substance and a charge-transporting substance is extremely important, but there are no general rules and it is extremely difficult to find a carrier-transporting substance that is compatible with a specific charge-generating substance. Therefore, as a result of intensive research, we have arrived at the present invention.

[Problem that the invention seeks to solve]

An object of the present invention is to provide an electrophotographic photoreceptor having sufficiently high sensitivity even in a long wavelength range.

An object of the present invention is to provide an electrophotographic photoreceptor that maintains a stable potential during repeated use and exhibits stable potential characteristics and image characteristics regardless of the usage environment (temperature, humidity).

[Means to solve the problem]

That is, the present invention provides an electrophotographic photoreceptor having a photosensitive layer on a conductive support, in which the photosensitive layer has a black angle 2θ±0.2° of CuKα in X-ray diffraction of 9.0°, 14.2°, Crystalline oxytitanium phthalocyanine having strong peaks at 23.9° and 27.1°, and the following general formula [I] (wherein R and R are a hydrogen atom that may have a substituent, a substituent R, R represents an alkyl group that may have a substituent, an aralkyl group that may have a substituent, or an aryl group that may have a substituent.

R and R represent an aryl group which may have a substituent.

) This is an electrophotographic photoreceptor characterized by containing a fluorene compound represented by the following.

The X-ray diffraction pattern of oxytitanium phthalocyanine in the present invention is as shown in FIGS. 1, 2, and 3 at Bragg angles (2θ±0.2°) of 9.0°, 14.
Strong peaks are shown at positions 2°, 23.9° and 27.1°. The above peaks are obtained by taking the top four points with the highest peak intensities, and are the main peaks.

What is characteristic about the X-ray diffraction diagrams in Figures 1, 2, and 3 is that among the four peaks mentioned above, the peak at 27.1° is the strongest, and the peak at 90° is the second. strong. Further, there is a peak weaker than the above four points at a position of 17.9° and an even weaker peak at a position of 13.3°.

Also 10.5° ~ 13.0°, 14.8° ~ 17.4°
And there is substantially no peak in the range of 18.2° to 232°.

In addition, in the present invention, the peak shape of X-ray diffraction may vary due to differences in manufacturing conditions, measurement conditions, etc.
There may be a slight difference, for example, the tip of each peak may be split. In the case of Figure 1, 8.9
The peak at 14.2 degrees has another split peak near 14.1 degrees.

Here, the structure of oxytitanium phthalocyanine is It is expressed as

However, XI, X2. X3. X4 is CZ or B
It represents r, and n, m, and E are integers of O to 4.

Aryl groups in the fluorene compound represented by general formula (1) used in the present invention include phenyl, naphthyl, and pyridyl; alkyl groups include methyl, ethyl, and propyl; and aralkyl groups include benzyl and Examples include fenithyl. In addition, the substituents that may be included include alkyl groups, alkoxy groups such as methoxy and ethoxy, aryl groups,
Examples include halogen atoms such as fluorine, chlorine and bromine, and hydroxyl groups.

Representative examples of the fluorene compound represented by the general formula CI] used in the present invention are shown below.

The reason why the combination of the crystalline oxytitanium phthalocyanine of the present invention and the fluorene compound of the present invention is preferable is not clear, but it is probably due to the compatibility of the ionization potential or the interface between the oxytitanium phthalocyanine, which is a charge generating substance, and the fluorene compound, which is a charge transporting substance. Due to its good three-dimensional shape, charge injection from the charge generating substance to the charge transporting substance is performed well, resulting in good sensitivity, low residual potential, and excellent potential stability during repeated use. It seems that there are.

An example of the method for producing oxytitanium phthalocyanine used in the present invention will be described below.

First, for example, titanium tetrachloride and orthophthalodinitrile are reacted in α-chlornaphthalene to obtain dichlorotitanium phthalocyanine. This is washed with a solvent such as α-chloronaphthalene, trichlorobenzene, dichlorobenzene, N-methylpyrrolidone, N,N-dimethylformamide, etc., then washed with a solvent such as methanol or ethanol, and then hydrolyzed with hot water. Oxytitanium phthalocyanine crystals are obtained. The crystals thus obtained are often a mixture of various polymorphs, and it is usually difficult to obtain the crystalline form of oxytitanium phthalocyanine of the present invention even if this mixture is processed. Therefore, in the present invention, it is first converted into amorphous oxytitanium phthalocyanine by processing using the acitrate ink method.

The obtained amorphous oxytitanium phthalocyanine is treated with methanol at room temperature under heating or boiling for 30 minutes or more, preferably 1 hour or more, then dried under reduced pressure, and further treated with n-propyl ether, n-butyl ether, 1SO
- Ether solvents such as butyl ether, 5eC-butyl ether, n-amyl ether, n-butyl methyl ether, n-butyl ethyl ether, ethylene glycol n-butyl ether, monoterpene hydrocarbon solvents such as terpinolene and pinene, and liquid paraffin. The crystalline oxytitanium phthalocyanine of the present invention can be obtained by milling for 5 hours or more, preferably 10 hours or more using a solvent as a dispersion medium.

Note that the methanol treatment here refers to, for example, a suspension stirring treatment of oxytitanium phthalonanine in methanol. Moreover, the milling process refers to a process performed using a milling process such as a Santo mill or a whole mill with dispersion media such as glass beads, steel beads, and alumina balls.

An electrophotographic photoreceptor using an oxytitanium phthalocyanine crystal and a fluorene compound of the present invention will be described below.

First, a typical layer structure of an electrophotographic photoreceptor is shown in FIGS. 10 and 11.

In FIG. 10, the photosensitive layer 1 consists of a single layer, and the photosensitive layer 1 simultaneously contains a charge generating substance 2 and a charge transporting substance (not shown).

Note that 3 is a conductive support.

In FIG. 11, the photosensitive layer 1 has a laminated structure of a charge generation layer 4 and a charge transport layer 5, and the charge generation layer 4 has a charge generation substance 2.
The charge transport layer 5 contains a charge transport material (not shown).

Note that the stacking relationship between the charge generation layer 4 and the charge transport layer 5 in FIG. 11 may be reversed.

When manufacturing an electrophotographic photoreceptor, the conductive support 3 may be any material as long as it has conductivity, such as metals such as aluminum and stainless steel, metals with conductive layers, plastics, and paper. Examples include a cylindrical shape or a film shape.

Furthermore, a subbing layer having barrier and adhesive functions may be provided between the conductive support 3 and the photosensitive layer 1.

As the material for the undercoat layer, polyvinyl alcohol, polyethylene oxide, ethyl cellulose, methyl cellulose, casein, polyamide, glue, seratin, etc. are used.

These are dissolved in a suitable solvent and applied onto a conductive support. The film thickness is 0.2 to 3.0 μm.

When forming a photosensitive layer consisting of a single layer as shown in FIG. 10, it can be obtained by mixing the charge-generating substance and charge-transporting substance of the oxytitanium phthalocyanine crystal of the present invention in a suitable binder resin solution, and coating and drying the mixture. .

The charge generating layer of the photosensitive layer having a laminated structure as shown in FIG. 10 can be formed by dispersing the oxytitanium phthalocyanine charge generating material of the present invention together with a suitable binder resin solution, coating and drying. In this case, the binder resin may also be used.

Examples of the binder resin used here include polyester resin, acrylic resin, polyvinyl carbazole resin, phenoxy resin, polycarbonate resin, polyvinyl butyral resin, polystyrene resin, polyvinyl acetate resin, polysulfone resin, polyarylate resin, vinylidene chloride resin, etc. Acrylonitrile copolymer resin etc. are mainly used.

The charge transport layer is mainly formed by applying and drying a paint in which a charge transport material and a binder resin are dissolved in a solvent.

Moreover, as the binder resin, those mentioned above can be used.

Coating methods for these photosensitive layers include dipping,
Spray coating method, spinner coating method,
A bead coating method, a plate coating method, a beam coating method, etc. can be used.

When the photosensitive layer is a single layer, the appropriate film thickness is 5 to 40 μm, preferably 10 to 30 μm.

Further, when the photosensitive layer has a laminated structure, the thickness of the charge generation layer is 0.
The thickness of the charge transport layer is 5 to 40 μm, preferably 10 μm to 10 μm, preferably 0.05 to 58 μm.
It is in the range of ~30 μm.

Furthermore, in order to protect these photosensitive layers from external impacts, a thin resin layer or a resin layer in which conductive particles are dispersed may be provided as a protective layer on the surface of the photosensitive layer.

When the oxytitanium phthalocyanine crystal of the present invention is used as a charge-generating substance, it can be mixed with other charge-generating substances depending on the purpose.

Such electrophotographic photoreceptors can be widely applied not only to printers such as racer beam printers, LED printers, and CRT printers, but also to ordinary electrophotographic copying machines and other electrophotographic application fields.

Next, an example of manufacturing the oxytitanium phthalocyanine crystal of the present invention will be shown.

[Production Example 1] In 100 g of α-chlornaphthalene, 5.0 g of 0-phthalodinitrile, 2.0 g of titanium tetrachloride. 3 Og at 200°C
After heating and stirring for an hour, the mixture was cooled to 50° C., and the precipitated crystals were filtered off to obtain a paste of dichlorotitanium phthalocyanine. Next, this was heated to 100°C in N,N'-dimethylformamide Loom I! The mixture was washed with stirring, then washed twice with 100 mE of methanol at 60°C, and then filtered. Further, the resulting paste was stirred in 100 ml of deionized water at 80° C. for 1 hour and filtered to obtain blue oxytitanium phthalocyanine crystals. Yield 4.
3g0 The elemental analysis values of this compound were as follows.

Elemental analysis value (C32H+5NsTiO)HNCn Calculated value (%) 66.68 2.8019.44 0
．． 00 Actual value (%) 66.50 2.9919.4
2 0.47 Next, the crystals were dissolved in 30 ml of concentrated sulfuric acid, and added dropwise to 300 ml of deionized water at 20°C under stirring to cause reprecipitation. After filtration and thorough washing with water, the amorphous crystals were dissolved. Oxytitanium phthalocyanine was obtained. Amorphous oxytitanium phthalocyanine 4 thus obtained
．． 0g to 100ml of methanol I! The suspension was stirred at medium room temperature (22° C.) for 8 hours, filtered, and dried under reduced pressure to obtain low crystalline oxytitanium phthalocyanine.

Next, 40 ml of n-butyl ether was added to 2.0 g of this oxytitanium phthalocyanine, and the mixture was milled with 1 mm diameter glass beads for 20 minutes at room temperature (22°C).
Time went.

The solid content was taken out from this dispersion, thoroughly washed with methanol and then water, and dried to obtain the novel crystalline oxytitanium phthalocyanine of the present invention. Collection fi 1.8g0
The X-ray diffraction pattern of this oxytitanium phthalocyanine is shown in FIG. Further, a KBr pellet was prepared and the infrared absorption spectrum of this crystal was measured, and the results are shown in FIG.

FIG. 8 shows the results of the U.sup.2 absorption spectrum measured using a dispersion of this crystal in n-butyl ether.

[Production Example 2] 2.0 g of methanol-treated oxytitanium phthalocyanine obtained in the same manner as Production Example 1 and 50 m of pinene
1 was added thereto, and milling was performed at room temperature (22° C.) for 20 hours with glass beads of 1 mm diameter.

The solid content was taken out from this dispersion, thoroughly washed with methanol and then water, and dried to obtain the novel oxytitanium phthalocyanine of the present invention. Yield: 1.8 g The X-ray diffraction pattern of this oxytitanium phthalocyanine is shown in FIG.

[Production Example 3] 100 mβ of methanol was added to 4.0 g of amorphous oxytitanium phthalocyanine obtained by the same method as Production Example 1, and the mixture was boiled for 30 hours under suspension stirring, and then filtered and dried under reduced pressure. Oxytitanium phthalocyanine crystals were obtained. Yield: 3.6 go Next, 60 ml of ethylene glycol n-butyl ether was added to 2.0 g of this oxytitanium phthalocyanine, and milling was performed at room temperature (22°C) for 15 hours with glass beads of 1 mm diameter. The solid content was taken out from this dispersion, thoroughly washed with methanol and then water, and dried to obtain the novel oxytitanium phthalocyanine of the present invention. Yield: 1.8 g The X-ray diffraction pattern of this oxytitanium phthalocyanine is shown in FIG.

[Comparative Production Example 1] JP-A No. 61-239248 (USP 4,728,
592), the so-called α
A crystalline form of oxytitanium phthalocyanine, which is called a type, was obtained.

This X-ray diffraction diagram is shown in FIG.

[Comparative Production Example 2] Japanese Patent Application Laid-Open No. 62-67094 (USP 4,664,9
According to the production example disclosed in 97), a crystalline oxytitanium phthalocyanine, so-called type A, was obtained.

This X-ray diffraction diagram is shown in FIG.

[Comparative Production Example 3] According to the production example disclosed in JP-A-64-17066, oxytitanium phthalocyanine having the same crystal form as JP-A-64-17066 was obtained.

This X-ray diffraction diagram is shown in FIG.

In addition, the measurement of the X-ray diffraction pattern in the present invention was carried out using CuKa rays under the following conditions.

Measuring device used: Rigaku Denki X-ray diffraction device RAD-A system X-ray tube: Cu Tube voltage: 50kV Tube current: 40mA Scan method: 2θ/θ scan Scan speed: 2deg/min.

Sampling interval: 0.020deg.

Start angle (2θ): 3deg.

Stop angle (2θ): 40deg.

Divergence slit: 0.5deg Scatter link slit: 0.5d+4 receiving slit: 0.3mm Using a curved monochromator The present invention will be explained below by way of examples. Note that parts indicate parts by weight.

[Example 1] 0.8 μm of vinyl chloride-maleic anhydride on an aluminum plate
An undercoat layer made of vinyl acetate copolymer resin was provided.

Next, 4 parts of crystalline oxytitanium phthalocyanine obtained in Production Example 1 of the present invention and 2 parts of polyvinyl butyral resin were added to 90 parts of cyclohexanone, dispersed in a sand mill for 20 hours, and diluted by adding 100 parts of methyl ethyl ketone. A charge generation layer having a thickness of 0.2 μm after drying was formed on the undercoat layer.

Next, 5 g of the above-exemplified fluorene compound (18) and 5 g of hisphenol Z type polycarbonate resin (viscosity average molecular weight 50.000) were dissolved in 35 g of chlorobenzene, and this was placed on the charge generation layer so that the film thickness after drying would be 18 μm. A charge transport layer was formed by coating with a Mayer bar to prepare photoreceptor No. 1.

[Comparative Example 1] An electrophotographic photoreceptor (comparative photoreceptor No. 1) was produced in the same manner as in Example 1, except that the α-type oxytitanium phthalocyanine obtained in Comparative Production Example 1 was used.

[Comparative Example 2] An electrophotographic photoreceptor (comparative photoreceptor No. 2) was produced in the same manner as in Example 1, except that type A oxytitanium phthalocyanine obtained in Comparative Production Example 2 was used.

[Comparative Example 3] An electrophotographic photoreceptor (comparative photoreceptor No. , 3) were manufactured.

The electrophotographic photoreceptors of Example 1 and Comparative Examples 1, 2, and 3 were used in a laser beam printer (product name: LBP-3X).
: Paste it on the cylinder of a modified Canon machine and set it to charge so that the dark potential becomes -700 (V), and irradiate it with a laser beam with a wavelength of 802 nm to achieve -700 (V).
The amount of light required to lower the potential to -100 (V) was measured and defined as the sensitivity. Furthermore, the potential when irradiated with a light amount of 20 μJ/crn' was measured as the residual potential Vr. The results are shown in Table 1.

Table 1 In addition, Example 1 was prepared using the crystalline oxytitanium phthalocyanine obtained in Production Example 2 and Production Example 3, respectively.
An electrophotographic photoreceptor was manufactured in the same manner as in Example 1, and the sensitivity was measured. As a result, high sensitivity characteristics were obtained as in Example 1.

Next, these four types of photoreceptors were heated at a humidity of 10% and a temperature of 50C1.
Humidity 50%, temperature 18°C1 Humidity 80%, temperature 35°C
A continuous 3,000-sheet paper passing durability test was conducted under the following three environments, with the dark potential potential set at -700 (V) and the bright potential potential -100 (V), respectively, and the potentials of the dark and light areas after the durability test were measured and the images were evaluated. was evaluated.

In Example 1, good images equivalent to those in the initial stage were obtained in any environment after durability, but in Comparative Examples 1.2.
In No. 3, the white background part had sagging in all three environments, and Comparative Example No. 3 was particularly weak under conditions of humidity of 80% and temperature of 35°C.

In addition, in Comparative Examples 1, 2, and 3, when the density was adjusted using the density adjustment lever to remove soil blur, the density of the black background portion was insufficient.

Incidentally, FIG. 9 shows the distribution of spectral sensitivity in the case where the maximum value of spectral sensitivity is 100 in the electrophotographic photoreceptor of Example 1.

In this way, the electrophotographic photoreceptor of the present invention has a molecular weight of 770 to 810.
It exhibits stable high sensitivity characteristics in the long wavelength region around nm.

[Examples 2 to 10] Example 1 Combining the oxytitanium phthalocyanine produced in Production Example 1 and several types of fluorene compounds listed above
A photoreceptor was prepared in the same manner as described above. These photoreceptors were printed using a racer beam printer (product name: LB) in the same manner as in Example 1.
P-3X (manufactured by Canon) was pasted on the cylinder of a modified machine and charged so that the dark potential was -700 (V), and irradiated with 802 nm laser light to -700 (V).
The amount of light EΔsoo required to lower the potential of V) to -100 (V) was measured. Further, the potential when a light amount of 20 μJ/cm' was irradiated was measured as the residual potential Vr.

After resetting these photoreceptors so that the dark area potential is -700 (V) and the bright area potential is -200 (V), continuous
The sheets were subjected to paper feeding durability, and the fluctuation amounts ΔVD and ΔVL in the dark area potential and bright area potential were measured at the initial stage and after 3000 sheets.

These results are shown in Table 2.

[Comparative Examples 4 to 21] Photoreceptors were prepared in the same manner as in Examples 2 to 1O, except that the oxytitanium phthalocyanine produced in Comparative Production Examples 1 to 3 and the fluorene compounds of Examples 2 to 10 were combined, and evaluated in the same manner. did.

・'2〉 (hereinafter referred to as pot-sniff 1) "-1-7' [Comparative Examples 22 to 27] Compounds H-1, H-2, and 8-3 with the following structures instead of the fluorene compounds of Examples 2 to 10 ,H-4,H-5,H-
Comparative photoreceptors 1-13 were prepared in the same manner as in Examples 2-10 except that 6 was used as the charge transport material.As is clear from the results in Tables 2-4, the photoreceptors of the present invention It can be seen that the sensitivity, residual potential, and repeatability are extremely excellent.

[Example 11] A subbing layer similar to that in Example 1 was formed using a bar code on an aluminum sheet substrate having a thickness of 50 μm, and a charge transport layer similar to that in Example 1 was further formed thereon to a thickness of 20 μm.

Next, 5 parts of bisphenol Z type recarbonate were dissolved in 68 parts of cyclohexanone, 3 parts of oxytitanium phthalocyanine showing the X-ray diffraction pattern obtained in Production Example 1 was mixed with this solution, and the mixture was heated in a sand mill for 1 hour. After dispersion, 5 parts of bisphenol Z-type child recarbonate and 10 parts of the charge transport material used in Example 1 were dissolved, and 40 parts of tetrahydrofuran and 40 parts of dichloromethane were added for dilution to obtain a dispersed paint. This paint was applied onto the charge transport layer by a spray coating method and dried to form a charge generation layer with a thickness of 6 μm, thereby producing an electrophotographic photoreceptor.

[Comparative Example 28] An electrophotographic photoreceptor was produced in the same manner as in Example 11, except that α-type okine titanium phthalocyanine obtained in Comparative Production Example 1 was used as the charge-generating material.

[Comparative Example 29] An electrophotographic photoreceptor was produced in the same manner as in Example 11, except that type A oxytitanium phthalocyanine obtained in Comparative Production Example 2 was used as the charge generating material.

[Comparative Example 30] JP-A-64 obtained in Comparative Production Example 3 as a charge generating material
An electrophotographic photoreceptor was produced in the same manner as in Example 11, except that the same crystal form of oxytitanium phthalocyanine as in Publication No. 17066 was used.

Example 11 and Comparative Example 28.29゜3 thus obtained
0 electrophotographic photoreceptor was tested using an electrostatic tester (EPA-810
0: manufactured by Kawaguchi Electric).

The evaluation begins with a surface potential of 700 due to positive corona charging.
(V), and then exposed to monochromatic light of 802 nm separated by a monochromator, and the amount of light when the surface potential decreased to 200 (V) was measured, and the sensitivity was determined. The results are shown in Table 5.

Table 5 [Example 12] On an aluminum substrate, 5 g of N-methquine methylated 6 nylon resin (weight average molecular weight 45,000) and alcohol-soluble copolymerized nylon resin (weight average molecular weight 50°000) were placed on an aluminum substrate.
) A solution obtained by dissolving Log in 95 g of methanol was applied using a Meyer bar to provide an undercoat layer having a dry film thickness of 1 μm.

Next, 10 g of oxytitanium phthalocyanine showing the X-ray diffraction pattern obtained in Production Example 1, polyhinyl butyral resin (butyral conversion rate 65%, weight average molecular weight 45,
000) and 200 g of cyclohexane were dispersed for 24 hours using a hole mill disperser. This dispersion was applied onto the previously produced undercoat layer by a flute coach ink method to form a charge generation layer having a thickness of 0.2 μm after drying.

Next, 10 g of the fluorene compound No. 29 and bisphenol Z type polycarbonate resin (weight average molecular weight 45,000) were dissolved in 70 g of monochlorobenzene, and a plate coach ink was applied onto the previously formed charge generation layer. A charge transport layer having a thickness of 18 .mu.m after drying was formed by coating by the method.

A corona discharge of 15 KV was applied to the photoreceptor thus prepared. The surface potential (initial potential Vo) at this time was measured. Furthermore, the surface potential of this photoreceptor was measured after it was treated in a dark place for 1 second. Sensitivity is the exposure amount required to attenuate the potential V1 after dark decay to 1/6 (El/6: μJ
/crn'). At this time, an indium/potassium/aluminum/phosphorus quaternary semiconductor laser (power output: 5 mW; oscillation wavelength: 680 nm) was used as a light source. These results were as follows.

Vo: -690 (V) V+: -685
(V) E1/6・0.41 (μJ/c) Next, the above photoreceptor was placed in a laser beam printer (LBP-3X manufactured by Canon), which is a reversal development type electrophotographic printer equipped with the same semiconductor laser. I installed it and did an actual image forming test. The conditions are as follows.

-Surface potential knee 700V after second electric resistance, surface potential knee 150V after image exposure (exposure amount 2.0 pJ/cm'
) Transfer potential +700■, development polarity; negative polarity, process speed; 50 mm/sec, development conditions (development bias); -450V, scan method after image exposure; image scan, -second charge pre-exposure; 501 ux sec red Full-surface exposure and image formation were performed by line scanning a laser beam according to the character and image signals, but the characters and
Good prints were obtained for both images.

Furthermore, when 5,000 images were printed continuously, stable prints were obtained from the initial stage up to 5,000 sheets.

〔Effect of the invention〕

By combining the crystalline oxytitanium phthalocyanine and fluorene compound of the present invention, (1) it has high sensitivity in a long wavelength range such as the oscillation wavelength of a laser diode, and (2) it has stable image characteristics in the electrophotographic process. (3) It is possible to provide an electrophotographic photoreceptor with excellent potential stability.

[Brief explanation of drawings]

Figures 1, 2, and 3 are X-ray diffraction diagrams of crystalline oxytitanium phthalocyanine of the present invention obtained in production examples, and Figures 4, 5, and 6 are comparative production examples. An X-ray diffraction diagram of the obtained oxytitanium phthalocyanine, FIG. 7 is an infrared absorption spectrum diagram (KBr tablet method) of the crystalline oxytitanium phthalocyanine of the present invention, and FIG. 8 is an infrared absorption spectrum diagram of the crystalline oxytitanium phthalocyanine of the present invention. FIG. 9 is a diagram showing the spectral sensitivity of the electrophotographic photoreceptor of Example 1, and FIGS. 10 and 11 are schematic cross-sectional views of the layer structure of the electrophotographic photoreceptor. Wave I length 7777'1

Claims (2)

[Claims] (1) In an electrophotographic photoreceptor having a photosensitive layer on a conductive support, the photosensitive layer has a Bragg angle 2θ±0.2° of CuKα in X-ray diffraction of 9.0°, 14.2°, 23.
Crystalline oxytitanium phthalocyanine having strong peaks at 9° and 27.1°, and the following general formula [
I 〕 ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [ I 〕 (In the formula, R^1 and R^2 are hydrogen atoms, alkyl groups that may have a substituent, and Indicates an aralkyl group or an aryl group that may have a substituent, and R^3, R^4, R^5 and R^
6 represents an aryl group which may have a substituent. ) An electrophotographic photoreceptor comprising a fluorene compound represented by the following. (2) R^1 and R^2 in the above general formula [I]
is an alkyl group that may have a substituent, R^3, R
The electrophotographic photoreceptor according to claim (1), wherein ^4, R^5 and R^6 are phenyl groups which may have a substituent.