JP2879370B2 - Electrophotographic photoreceptor, electrophotographic apparatus provided with the electrophotographic photoreceptor, and facsimile - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member, an electrophotographic apparatus provided with the electrophotographic photosensitive member, and a facsimile, and more particularly, to a specific charge generating substance and a specific charge transporting substance. TECHNICAL FIELD The present invention relates to an electrophotographic photosensitive member having a photosensitive layer containing, an electrophotographic apparatus provided with the electrophotographic photosensitive member, and a facsimile.

[Prior Art] Conventionally, as an electrophotographic photoreceptor, an inorganic photoreceptor having a photosensitive layer mainly composed of an inorganic photoconductive substance such as selenium, cadmium sulfide, and zinc oxide has been widely used. These are not always satisfactory in heat stability, moisture resistance, durability, and the like. In particular, selenium and cadmium sulfide are restricted in production and handling due to toxicity.

On the other hand, an organic photoreceptor having a photosensitive layer containing an organic photoconductive compound as a main component has many advantages such as compensating for the above-mentioned disadvantages of the inorganic photoreceptor, and has been receiving attention in recent years.

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

On the other hand, a function-separated type electrophotographic photoreceptor in which a charge generation function and a charge transport function are respectively assigned to different substances has brought remarkable improvements in sensitivity and durability, which have been regarded as disadvantages of conventional organic photoreceptors.

Such a function-separated type electrophotographic photoreceptor has an advantage that a material selection range of each of a charge generation material and a charge transport material is wide, and an electrophotographic photoreceptor having arbitrary characteristics can be relatively easily prepared. I have.

In recent years, the use of electrophotographic photosensitive members not only in copiers but also in non-impact printers to which electrophotographic technology is applied has been rapidly increasing. These are mainly laser beam printers using laser light as a light source, and a semiconductor laser is used as the light source from the viewpoint of cost and size of the apparatus.

Currently, mainly used semiconductor lasers have an oscillation wavelength of 790 ± 20 nm, which is a long wavelength. Therefore, development of an electrophotographic photoreceptor having sufficient sensitivity to such long-wavelength light has been advanced.

The sensitivity on the long wavelength side varies depending on the type of charge generation material, and many charge generation materials have been studied.

Representative charge generation materials include phthalocyanine pigments,
Examples include azo pigments, cyanine pigments, azulene pigments, and squarylium dyes.

On the other hand, as a charge generation material having sensitivity to long wavelength light, in recent years, aluminum chlorophthalocyanine, chloroindium phthalocyanine, oxyvanadium phthalocyanine, chlorogallium phthalocyanine, magnesium phthalocyanine, metal phthalocyanine such as oxytitanium phthalocyanine or metal-free phthalocyanine Research is increasing.

Among them, many phthalocyanine compounds are known to have polymorphs.
Type, β type, γ type, δ type, ε type, τ type, χ type, etc.
As copper phthalocyanine, α-type, β-type, γ-type, δ-type, and χ-type are known.

It is also known that the difference in crystal form greatly affects the electrophotographic characteristics (sensitivity, potential stability during durability, etc.) and the characteristics of the paint when it is made into a paint.

In particular, oxytitanium phthalocyanine, which has high sensitivity to long-wavelength light, also has polymorphism like other phthalocyanines such as the above-mentioned metal-free phthalocyanine and copper phthalocyanine.

For example, JP-A-59-49544 (USP 4,444,861), JP-A-59-166959, JP-A-61-239248 (USP
4,728,592) and JP-A-62-67094 (USP 4,664,99).
7), JP-A-63-366, JP-A-63-116158,
JP-A-63-198067 and JP-A-64-17066 each report oxytitanium phthalocyanine which is a crystal child.

However, these oxytitanium phthalocyanines have some problems in actual use such as insufficient sensitivity, poor potential stability during repeated use, poor chargeability, and image deterioration due to changes in the use environment. Yes,
There are still no satisfactory ones.

In general, in an electrophotographic photoreceptor, a charge transport material effective for a specific charge generating material is not always effective for another charge generating material, and conversely, a specific charge transport material is not effective. A charge-generating substance that is effective for a particular charge-transporting substance is not always effective. That is,
There is always an appropriate combination of these charge generating materials and charge transporting materials that transfer charges.

An improper combination causes many problems such as a reduction in sensitivity and an increase in residual potential, a deterioration in potential stability and a reduction in charging ability when repeatedly used.

Therefore, the combination of the charge generating material and the charge transporting material is extremely important, but there is no general rule, and it is not easy to find a charge transporting material suitable for a specific charge generating material.

[Problems to be Solved by the Invention] An object of the present invention is to provide an electrophotographic photoreceptor having a sufficiently high sensitivity in a laser diode oscillation wavelength region, to stably maintain a potential during repeated use, and to provide a use environment. An object of the present invention is to provide an electrophotographic photosensitive member exhibiting stable potential characteristics and image characteristics irrespective of (temperature, humidity), and to provide an electrophotographic device and a facsimile provided with the electrophotographic photosensitive member.

[Means for Solving the Problems and Action] The present invention provides a Bragg angle 2θ ± in X-ray diffraction of CuKα.
Strong peaks at 9.0 ゜, 14.2 ゜, 23.9 ゜ and 27.1 ゜ of 0.2 ゜, 10.5 ゜ -13.0 ゜, 14.8 ゜ -17.4 ゜ and 18.2
An electrophotographic photoreceptor comprising a crystalline form of oxytitanium phthalocyanine having no strong peak in the range of {23.2} and a compound represented by the following general formula (1): You.

General formula In the formula, X represents an oxygen atom or a sulfur atom, and R ₁ ,
R ₂ , R ₃ and R ₄ represent an alkyl group, an aralkyl group or an aryl group which may have a substituent.

Specifically, alkyl groups include groups such as methyl, ethyl and propyl; aralkyl groups include groups such as benzyl and phenethyl; and aryl groups include groups such as phenyl and naphthyl.

Examples of the substituent which the alkyl group, the aralkyl group and the aryl group may have include an alkyl group such as methyl, ethyl, and propyl; an alkoxy group such as methoxy and ethoxy; a halogen atom such as a fluorine atom, a chlorine atom and a bromine atom; And aryl groups such as phenyl.

X of the oxytitanium phthalocyanine in the present invention
As shown in FIGS. 1, 2 and 3, the line diffraction patterns were 9.0 °, 14.2 ° and 23.9 of Bragg angles (2θ ± 0.2 °).
Strong peaks are shown at 2 and 27.1 ゜. The above-mentioned peaks are the top four points having the highest peak intensities, and are the main peaks.

The characteristic features of the X-ray diffraction diagrams of FIGS. 1, 2 and 3 are that the peak at 27.1 ° is the strongest and the peak at 9.0 ° is the second strongest among the above four peaks.

Further, a peak weaker than the above four points and a weaker peak are located at 13.3 ° at 17.9 °.

10.5 to 13.0, 14.8 to 17.4, and 18.2 to
There is substantially no peak in the range of 23.2 ゜.

In the present invention, the peak shape of the X-ray diffraction is slightly different depending on a difference in manufacturing conditions and a measuring condition. For example, the tip of each peak may be split.

In the case of Fig. 1, the peak of 8.9 ゜ peaks around 9.4 ゜,
The peak of 14.2 ゜ has another split peak near 14.1 ゜.

The structure of oxytitanium phthalocyanine is represented by the following formula.

In the formula, X ₁ , X ₂ , X ₃ and X ₄ represent Cl or Br, and n,
m, l and k are integers from 0 to 4.

Further, the present invention comprises an electrophotographic apparatus provided with the electrophotographic photoreceptor of the present invention.

Further, the present invention comprises an electrophotographic apparatus having the electrophotographic photoreceptor of the present invention and a facsimile having a receiving means for receiving image information from a remote terminal.

Hereinafter, typical specific examples of the compound represented by the general formula (1) will be listed.

 However, it is not limited to these compounds.

The description of the compound examples is by showing only the variable parts R ₁ , R ₂ , R ₃ and R ₄ in the basic form.

The combination of the particular crystalline form of oxytitanium phthalocyanine with the particular compound in the present invention may be due to, for example, better ionization potential or better steric overlap at the interface between the charge generating material and the charge transport material.
Since the charge injection from the charge generating substance to the charge transporting substance is performed well, it is considered that the sensitivity is good, the residual potential is small, and the potential stability upon repeated use is excellent.

The method for producing the crystalline form of oxytitanium phthalocyanine used in the present invention will be exemplified. For example, titanium tetrachloride and orthophthalodinitrile are reacted in α-chloronaphthalene to obtain dichlorotitanium phthalocyanine.

This is called α-chloronaphthalene, trichlorobenzene,
After washing with a solvent such as dichlorobenzene, N-methylpyrrolidone, N, N-dimethylformamide and the like, and then washing with a solvent such as methanol and ethanol, hydrolysis with hot water is performed to obtain oxytitanium phthalocyanine crystals.

The crystals thus obtained are often mixtures of various polymorphs, and it is usually difficult to obtain the crystalline form of oxytitanium phthalocyanine used in the present invention even by treating this mixture.

Therefore, in order to be suitable for use in the present invention, it is converted into amorphous oxytitanium phthalocyanine by a treatment by an acid pacing method.

The obtained amorphous oxytitanium phthalocyanine is treated with methanol at room temperature, under heating or boiling, preferably for 1 hour or more, and then dried under reduced pressure, and further n-propyl ether, n-butyl ether, iso-butyl ether, sec. -Butyl ether, n-amyl ether, n
-Butyl methyl ether, n-butyl ethyl ether,
Milling for 5 hours or more, preferably 10 hours or more using an ether solvent such as ethylene glycol-n-butyl ether or a monoterpene hydrocarbon solvent such as terpinolene or pinene or a solvent such as liquid paraffin as a dispersion medium. Thus, the crystalline form of oxytitanium phthalocyanine used in the present invention is obtained.

Here, the methanol treatment means, for example, a suspension and stirring treatment of oxytitanium phthalocyanine in methanol.

The milling process refers to a process performed using a milling device such as a sand mill and a ball mill together with a dispersion medium such as glass beads, steel beads, and alumina balls.

The electrophotographic photoreceptor using the crystalline oxytitanium phthalocyanine of the present invention and the compound represented by the general formula (1) will be described. First, a typical layer constitution of the electrophotographic photoreceptor is that the photosensitive layer is composed of a single layer. The photosensitive layer contains a charge generating material and a charge transport material simultaneously and is formed on a conductive support.

Further, there is a laminate type in which a photosensitive layer has a structure in which a charge generation layer containing a charge generation material and a charge transport layer containing a charge transport material are sequentially laminated on a conductive support. The stacking relationship of the charge transport layers may be reversed.

As the conductive support, any material having conductivity may be used, and metals and alloys such as aluminum and stainless steel, metals, alloys, plastics and papers provided with a conductive layer are used, and the shape is cylindrical or film-like. There is.

An undercoat layer having a barrier function and an adhesive function can be formed between the conductive support and the photosensitive layer.

As a material for the undercoat layer, polyvinyl alcohol, polyethylene oxide, ethyl cellulose, methyl cellulose, casein, polyamide, glue, gelatin and the like are used.

The material is dissolved in a suitable solvent and applied on a conductive support. The thickness is 0.2 to 3.0 μm.

The photosensitive layer composed of a single layer is formed by mixing the charge generating material of the oxytitanium phthalocyanine crystal used in the present invention and the charge transporting material of the compound represented by the general formula (1) in an appropriate binder resin solution, coating and drying. Is done.

The photosensitive layer having a laminated structure, the charge generation layer is formed by dispersing the charge generation material of the oxytitanium phthalocyanine crystal used in the present invention together with a suitable binder resin solution, and coating and drying. Is also good.

As the binder resin, for example, polyester, acrylic resin, polyvinyl carbazole, phenoxy resin,
Polycarbonate, polyvinyl butyral, polystyrene, polyvinyl acetate, polysulfone, polyarylate, vinylidene chloride / acrylonitrile copolymer and the like are mainly used.

The charge transport layer is formed by applying and drying a coating material in which a charge transport material of the compound represented by the general formula (1) and a binder resin are dissolved in a solvent.

As the binder resin, those similar to the above-mentioned binder resins can be used.

Examples of the method for applying the photosensitive layer include a dip coating method, a spray coating method, a spinner coating method, a bead coating method, a blade coating method, and a beam coating method.

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

When the photosensitive layer has a laminated structure, the thickness of the charge generation layer is
The thickness is 0.01 to 10 μm, preferably 0.05 to 5 μm, and the thickness of the charge transport layer is 5 to 40 μm, preferably 10 to 30 μm.

Further, a thin protective layer may be provided on the surface of the photosensitive layer in order to protect the photosensitive layer from external impact.

When the oxytitanium phthalocyanine crystal of the present invention is used as a charge generation material, it can be used in combination with another charge generation material depending on the purpose.

The electrophotographic photoreceptor of the present invention can be widely applied not only to printers such as laser beam printers, LED printers, and CRT printers, but also to general electrophotographic copying machines, facsimile machines, and other electrophotographic applications.

Next, an electrophotographic apparatus and a facsimile provided with the electrophotographic photosensitive member of the present invention will be described.

FIG. 10 shows a schematic configuration of a general transfer type electrophotographic apparatus using the drum type photoreceptor of the present invention.

In FIG. 1, reference numeral 1 denotes a drum-type photosensitive member as an image carrier, which is driven to rotate at a predetermined peripheral speed in the direction of an arrow around a shaft 1a. The photoreceptor 1 is uniformly charged at a predetermined positive or negative potential on its peripheral surface by a charging means 2 during the rotation process, and then exposed at a light exposure section 3 by an image exposure means (not shown) at an exposure section 3.
(Slit exposure, laser beam scanning exposure, etc.).

As a result, an electrostatic latent image corresponding to the exposure image is sequentially formed on the peripheral surface of the photoconductor.

The electrostatic latent image is then developed with toner by a developing unit 4, and the developed toner image is transferred by a transfer unit 5 between a photosensitive unit 1 and a transfer unit 5 from a paper supply unit (not shown) in synchronization with the rotation of the photosensitive unit 1. It is sequentially transferred onto the surface of the transfer material P taken and fed.

The transfer material P having undergone the image transfer is separated from the photoreceptor surface, introduced into the image fixing means 8 and subjected to image fixing, and is printed out as a copy (copy) outside the machine.

The surface of the photoreceptor 1 after the image transfer is cleaned and cleaned by removing the untransferred toner by the cleaning means 6, subjected to a charge removal treatment by the pre-exposure means 7, and used repeatedly for image formation.

As the uniform charging means 2 for the photoreceptor 1, a corona charging device is generally widely used.

Also, the corona transfer means is generally widely used for the transfer device 5.

As an electrophotographic apparatus, a plurality of components such as the above-described photoreceptor, developing means, and cleaning means are integrally connected as an apparatus unit, and this unit is configured to be detachable from the apparatus body. May be. For example,
The photoreceptor 1 and the cleaning means 6 may be integrated into one apparatus unit, and may be configured to be detachable using guide means such as rails of the apparatus body. At this time, the above-described device unit may be provided with a charging unit and / or a developing unit.

In the case where the electrophotographic apparatus is used as a copier or a printer, the light image exposure L is performed by reflecting or transmitting light from the original, or by reading the original and converting it into a signal. This is performed by driving an array or driving a liquid crystal shutter array.

When used as a facsimile printer, the light image exposure L is an exposure for printing received data.

FIG. 11 is a block diagram showing an example of this case.

The controller 10 controls the image reading unit 9 and the printer 18.

The whole of the controller 10 is controlled by the CPU 16.

The read data from the image reading unit is transmitted to the partner station through the transmission circuit 12. Data received from the partner station is sent to the printer 18 through the receiving circuit 11. Predetermined image data is stored in the image memory. The printer controller 17 controls the printer 18. 13 is a telephone.

An image received from the line 14 (image information from a remote terminal connected via the line) is demodulated by the receiving circuit 11, and then the CPU 16 performs signal processing of the image information and is sequentially stored in the image memory 15. . When at least one page of the image is stored in the memory 16, the image of the page is stored.

The CPU 16 reads out one page of image information from the memory 15 and sends out one page of image information signaled to the printer controller 17.

When receiving the image information of one page from the CPU 16, the printer controller 17 controls the printer 18 to record the image information of the page.

Note that the CPU 16 is receiving the next page during recording by the printer 18.

 As described above, image reception and recording are performed.

Next, a production example of the oxytitanium phthalocyanine crystal used in the present invention will be described.

Production Example 1 o-phthalodinitrile in 100 g of α-chloronaphthalene
5.0 g and 2.0 g of titanium tetrachloride were heated and stirred at 200 ° C. for 3 hours, and then cooled to 50 ° C., and the precipitated crystals were separated by filtration to obtain a paste of dichlorotitanium phthalocyanine.

Next, this was washed under stirring with 100 ml of N, N-dimethylformamide heated to 100 ° C., and then 100 ml of methanol at 60 ° C.
The washing was repeated twice with and filtered. Further, the obtained paste was stirred in 100 ml of deionized water at 80 ° C. for 1 hour and filtered to obtain blue oxytitanium phthalocyanine crystal. Yield 4.3 g Elemental analysis (C ₃₂ H ₁₆ N ₈ TiO) Calculated (%) Observed (%) C 66.68 66.50 H 2.80 2.99 N 19.44 19.42 Cl 0.00 0.47 Next, the crystals were dissolved in 30 ml of concentrated sulfuric acid. After re-precipitation by dropping into 300 ml of deionized water at 300 ° C. with stirring, the solution was filtered and sufficiently washed with water to obtain amorphous oxytitanium phthalocyanine.

4.0 g of the amorphous oxytitanium phthalocyanine thus obtained was suspended and stirred in 100 ml of methanol at room temperature (22 ° C.) for 8 hours, filtered and dried under reduced pressure to obtain oxytitanium phthalocyanine of low crystallinity.

To 2.0 g of this oxytitanium phthalocyanine, 40 ml of n-butyl ether was added, and milling was performed at room temperature (22 ° C.) for 20 hours together with 1 mmφ glass beads.

The solid content was taken out of the dispersion, washed thoroughly with methanol and then with water, and dried to obtain a crystalline oxytitanium phthalocyanine used in the present invention. FIG. 1 shows an X-ray diffraction diagram of the obtained crystal form of oxytitanium phthalocyanine in a yield of 1.8 g.

FIG. 7 shows the results of preparing KBr pellets and measuring the infrared absorption spectrum of the crystals.

FIG. 8 shows the result of an ultraviolet absorption spectrum measured for a dispersion obtained by dispersing the crystals in n-butyl ether.

Production Example 2 50 ml of pinene was added to 2.0 g of methanol-treated oxytitanium phthalocyanine obtained in the same manner as in Production Example 1, and milling treatment was carried out together with 1 mmφ glass beads at room temperature (22 ° C.) for 20 hours. The solid content was taken out of the dispersion, washed thoroughly with methanol and then with water, and dried to obtain a crystalline oxytitanium phthalocyanine used in the present invention. FIG. 2 shows an X-ray diffraction pattern of the obtained crystal form of oxytitanium phthalocyanine in a yield of 1.8 g.

Production Example 3 To 4.0 g of amorphous oxytitanium phthalocyanine obtained in the same manner as in Production Example 1, 100 ml of methanol was added.
After the suspension was boiled for 30 hours under stirring, filtration and drying under reduced pressure were performed to obtain oxytitanium phthalocyanine crystals. yield
3.6 g Next, 60 ml of ethylene glycol-n-butyl ether was added to 2.0 g of this oxytitanium phthalocyanine, and 1 m
Milling treatment with mφ glass beads at room temperature (22
C) for 15 hours. The solid content was taken out of the dispersion, washed thoroughly with methanol and then with water, and dried to obtain a crystalline oxytitanium phthalocyanine used in the present invention. FIG. 3 shows an X-ray diffraction pattern of the obtained crystal form of oxytitanium phthalocyanine in a yield of 1.8 g.

Comparative Production Example 1 According to a production example disclosed in JP-A-61-239248 (US Pat. No. 4,728,592), a crystalline form of oxytitanium phthalocyanine, so-called α-form, was obtained.

 The X-ray diffraction pattern is shown in FIG.

Comparative Production Example 2 According to a production example disclosed in Japanese Patent Application Laid-Open No. 62-67094 (US Pat. No. 4,6649972), a crystalline form of oxytitanium phthalocyanine, so-called A type, was obtained.

 The X-ray diffraction pattern 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 that disclosed in JP-A-64-17066 was obtained.

 The X-ray diffraction pattern is shown in FIG.

The measurement of X-ray diffraction was carried out using CuKα rays under the following conditions.

 Measuring machine: Rigaku Denki Co., Ltd. X-ray diffractometer RAD-A system X-ray tube: Cu Tube voltage: 50KV Tube current: 40mA Scanning method: 2θ / θ scanning Scanning speed: 2deg./min. Sampling interval: 0.020 deg. Start angle (2θ): 3 deg. Stop angle (2θ): 40 deg. Divergence slit: 0.5 deg. Skuttering slit: 0.5 deg. Receiving slit: 0.3 mm Curved monochromator Example Parts in the examples are parts by weight.

Example 1 An undercoat layer of 1.0 μm vinyl chloride-maleic anhydride-vinyl acetate copolymer was formed on an aluminum plate.

Next, 5 parts of the crystalline oxytitanium phthalocyanine obtained in Production Example 1 and 2 parts of polyvinyl butyral were added to 90 parts of cyclohexanone, dispersed by a sand mill for 10 hours, and diluted with 100 parts of methyl ethyl ketone. The thickness of this dispersion after drying on the undercoat layer is 0.2 μm.
Was formed.

Next, 5 parts of the compound of Compound Example (10) and 5 parts of bisphenol Z-type polycarbonate (viscosity average molecular weight: 35,000) were dissolved in 40 parts of chlorobenzene, and this was dried on the charge generation layer to a film thickness of 18 μm. Apply with a Meyer bar to form a charge transport layer, create an electrophotographic photoreceptor,
This is designated as Photoconductor 1.

Comparative Example 1 An electrophotographic photosensitive member was prepared 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 photosensitive member was prepared in the same manner as in Example 1, except that the A-type oxytitanium phthalocyanine obtained in Comparative Production Example 2 was used.

Comparative Example 3 An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that oxytitanium phthalocyanine having the same crystal form as disclosed in JP-A-64-17066 obtained in Comparative Production Example 3 was used.
This is designated as Comparative Photoconductor 3.

The electrophotographic photoconductors of photoconductor 1, comparative photoconductors 1, 2, and 3 were attached to the cylinder of a remodeled laser beam printer (trade name: LBP-SX, manufactured by Canon Inc.).
Set the charging so that the dark area potential is -700 V, and set the wavelength
Irradiation of 802 nm laser light was _performed to measure the light amount E _Δ600 required to lower the potential of −700 V to −100 _V.

Was further measured quantity of 20 .mu.J / cm ² the potential of the case of irradiation as a residual potential V _r.

Further, an electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that the crystalline oxytitanium phthalocyanine obtained in Production Examples 2 and 3 was used as a charge generation material, and this was used as Photoreceptor 2 and The photoconductor 3 is referred to as a photoconductor 3.

When the sensitivity was measured in the same manner as in Example 1, high sensitivity characteristics similar to those of the photoreceptor 1 were obtained.

Next, for photoconductor 1, comparative photoconductors 1, 2 and 3, humidity 10%, temperature 5 ° C, humidity 50%, temperature 18 ° C, humidity 80
%, And in each environment of 35 ° C., with each photoreceptor set to a dark potential of −700 V and a bright potential of −100 V, continuous 3
A durability test was performed on 1,000 sheets to measure the potential of the dark part and the potential of the bright part after the durability test, and evaluated the image.

Photoreceptor 1 provided a good image equivalent to the initial one after endurance in any environment, but comparative photoreceptors 1, 2 and 3 had fog on a white background in any environment and had a humidity of 80 %, More remarkable at an air temperature of 35 ° C., and particularly remarkable for the comparative photoreceptor 3.

When the comparative photoreceptors 1, 2 and 3 were adjusted with a density adjusting lever to remove background fog, the density of the black background became insufficient.

FIG. 9 shows the distribution of the spectral sensitivity when the maximum value of the spectral sensitivity of the photoreceptor 1 is 100.

As described above, the electrophotographic photoreceptor of the present invention exhibits stable high sensitivity characteristics in a long wavelength region around 770 to 810 nm.

Examples 2 to 10 Electrophotographic photoreceptors were prepared in the same manner as in Example 1 except that the oxytitanium phthalocyanine crystal obtained in Production Example 1 was combined with several types of compound examples, and photoreceptors 2 to 10 were obtained.

Each photoconductor was attached to a cylinder of a remodeled machine of a laser beam printer (trade name: LBP-SX, manufactured by Canon Inc.) in the same manner as in Example 1, and the charge was set so that the dark area potential became -700 V. Is required to irradiate a laser beam with a wavelength of 802 nm to lower the potential of -700V to -100V.
_Δ600 was measured.

Was further measured quantity of 20 .mu.J / cm ² the potential of the case of irradiation as a residual potential V _r.

Further, with each photoreceptor being reset to a dark area potential of -700 V and a light area potential of -100 V, a continuous paper passing durability test of 3,000 sheets was performed. Variation ΔV _D
And ΔV ₁ were measured. The results are shown.

Comparative Examples 4 to 21 Examples 2, 5, 6, 7, 8 except that the oxytitanium phthalocyanine produced in Comparative Production Examples 1 to 3 was used in combination with the compound as the charge transporting material used in the above Examples.
An electrophotographic photoreceptor was prepared in the same manner as in Examples 9 and 9, and evaluated in the same manner.

Comparative Examples 22 to 27 Compounds of the following structural formulas H-1, H-2, H-3, H-4, H-5, H in place of compound example (2) in Example 2
An electrophotographic photoreceptor was prepared in the same manner as in Example 2 except that -6 was used as a charge transporting material, and this was compared with comparative photoreceptors 22 to
27, and similarly evaluated.

From the above results, it can be seen that the electrophotographic photoreceptor of the present invention is extremely excellent in sensitivity, residual potential and repetition characteristics.

Example 11 An undercoat layer similar to that of Example 1 was formed on an aluminum sheet substrate having a thickness of 50 μm by bar coating, and a charge transport layer similar to that of Example 1 was formed thereon to a thickness of 20 μm.

Next, 5 parts of bisphenol Z-type polycarbonate was dissolved in 68 parts of cyclohexanone, and 3 parts of oxytitanium phthalocyanine exhibiting the X-ray diffraction pattern obtained in Production Example 1 was mixed with the solution, and dispersed in a sand mill for 1 hour. Thereafter, 5 parts of bisphenol Z-type polycarbonate and 10 parts of the charge transporting material used in Example 1 were dissolved, and further diluted with 40 parts of tetrahydrofuran and 40 parts of dichloromethane to prepare a dispersion paint. This paint was applied on the charge transport layer by a spray coating method and dried to form a 6 μm-thick charge generation layer, thereby producing an electrophotographic photoreceptor.
And

Comparative Example 28 An electrophotographic photosensitive member was prepared in the same manner as in Example 11 except that the α-type oxytitanium phthalocyanine produced in Comparative Production Example 1 was used as the charge generating material.
And

Comparative Example 29 An electrophotographic photosensitive member was prepared in the same manner as in Example 11 except that the A-type oxytitanium phthalocyanine produced in Comparative Production Example 2 was used as the charge generating material.
And

Comparative Example 30 JP-A-64-64 produced in Comparative Production Example 3 as a charge generating material
An electrophotographic photoreceptor was prepared in the same manner as in Example 11 except that oxytitanium phthalocyanine having the same crystal form as that disclosed in JP-A-17066 was used.

Photoconductor 11 and comparative photoconductors 28, 29 and 30 were evaluated using an electrostatic tester (EPA-8100, manufactured by Kawaguchi Electric Co., Ltd.).

First, the surface potential was +700 V due to positive corona charging
Then, exposure was performed with monochromatic light of 802 nm separated by a monochromator, and the light quantity when the surface potential was lowered to +200 V was measured and defined as sensitivity. The results are shown. E _Δ600 (μJ / cm ² ) Example 11 0.32 Comparative Example 28 1.10 Comparative Example 29 1.08 Comparative Example 30 0.78 [Effect of the Invention] The electrophotographic photoreceptor of the present invention uses oxytitanium phthalocyanine of a specific crystal form as a charge generation material. By having a photosensitive layer using a specific compound as a charge transport material, (1) having high sensitivity at the laser diode oscillation wavelength,
(2) It has a remarkable effect of exhibiting stable image characteristics in an electrophotographic process and (3) being excellent in potential stability.

The same effect can be obtained in an electrophotographic apparatus and a facsimile equipped with the electrophotographic photosensitive member.

[Brief description of the drawings]

FIG. 1 is an X-ray diffraction pattern of the crystalline form of oxytitanium phthalocyanine obtained in Production Example 1, FIG. 2 is an X-ray diffraction pattern of the crystalline form of oxytitanium phthalocyanine obtained in Production Example 2, and FIG. 6 is an X-ray diffraction diagram of the crystalline form of oxytitanium phthalocyanine obtained in Production Example 3. FIG. 4 is an X-ray diffraction pattern of oxytitanium phthalocyanine obtained in Comparative Production Example 1, FIG. 5 is an X-ray diffraction pattern of oxytitanium phthalocyanine obtained in Comparative Production Example 2, and FIG. 6 is Comparative Production Example 3. FIG. 3 is an X-ray diffraction diagram of the oxytitanium phthalocyanine obtained in the above. FIG. 7 is an infrared absorption spectrum of the crystalline form of oxytitanium phthalocyanine obtained in Production Example 1 (KBr method), and FIG. 8 is an ultraviolet absorption spectrum of the crystalline form of oxytitanium phthalocyanine obtained in Production Example 1. It is. FIG. 9 is a spectral sensitivity distribution diagram of the electrophotographic photosensitive member (photosensitive member 1) prepared in Example 1. FIG. 10 is a schematic configuration diagram of a general transfer type electrophotographic apparatus using the drum type photoreceptor of the present invention. Reference numeral 1 denotes a drum-type photoconductor as an image carrier (electrophotographic photoconductor of the present invention), 2 denotes a corona charging device, 3 denotes an exposure unit,
Is a developing means, 5 is a transferring means, 6 is a cleaning means, 7
Denotes a pre-exposure unit, 8 denotes an image fixing unit, L denotes a light image exposure, and P denotes a transfer material that has undergone image transfer. FIG. 11 is a block diagram of a facsimile using the electrophotographic apparatus as a printer. Reference numeral 9 denotes an image reading unit, 10 denotes a controller, 11 denotes a receiving circuit, 12 denotes a transmitting circuit, 13 denotes a telephone, 14 denotes a line, 15 denotes an image memory, 16 denotes a CPU, 17 denotes a printer controller, and 18 denotes a printer.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-62-280850 (JP, A) JP-A-2-267563 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03G 5/06 570 G03G 5/06 315

Claims (4)

(57) [Claims] 1. Bragg angle 2θ in X-ray diffraction of CuKα
Has strong peaks at 9.0, 14.2, 23.9, and 27.1 at ± 0.2, 10.5 to 13.0, 14.8 to 17.4, and 1
An electrophotographic photoreceptor comprising a crystalline form of oxytitanium phthalocyanine having no strong peak in the range of 8.2 ° to 23.2 ° and a compound represented by the following general formula (1). General formula In the formula, X represents an oxygen atom or a sulfur atom, and R ₁ , R ₂ , R ₃
And R ₄ represent an alkyl group, an aralkyl group or an aryl group which may have a substituent. 2. The method according to claim ₁ , wherein at least two or more of R ₁ , R ₂ , R ₃ and R ₄ are phenyl groups which may have a substituent.
The electrophotographic photosensitive member according to the above. 3. An electrophotographic apparatus comprising the electrophotographic photosensitive member according to claim 1. 4. A facsimile having an electrophotographic apparatus provided with the electrophotographic photosensitive member according to claim 1 and a receiving means for receiving image information from a remote terminal.