JP2000194154A - Electrophotographic photoreceptor, process cartridge and electrophotographic apparatus using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor small in resion embossing impression and high in scratch resistance on the surface in long repeated uses and capable of obtaining defectless images for a long period by incorporating an elasticizing filler or compound in the binder resin of the surface layer of the photoreceptor. SOLUTION: The electrophotographic photoreceptor is provided on a support with the photosensitive layer and the binder resin of its surface layer contains the elasticizing filler or compound, and resin granule obtained, for example, by polymerization of a monomer in an aqueous dispersion or nondispersion medium and pulverization and spray drying or the like processes may be used as the filler. The resin may be a homopolymer or copolymer, and elastic optionally cross-linked fine particles of acrylic, polyester, urethane, polyethylene, polypropylene, butadiene, styrene/butadiene, silicone, and the like exemplified as resin, are used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photoreceptor, and more particularly, to a photoreceptor containing an organic conductive compound.
An electrophotographic photoreceptor having a surface layer for protecting its surface,
The present invention relates to a process cartridge having the electrophotographic photosensitive member and an electrophotographic apparatus.

[0002]

2. Description of the Related Art An electrophotographic method is disclosed in U.S. Pat.
As shown in the specification, a photoconductive material is used in which the electric resistance changes according to the irradiation amount received during image exposure and which is made of a support coated with an insulating substance in a dark place. The basic characteristics required for electrophotography using this photoconductive material include (1) charging to an appropriate potential in a dark place, (2) little dissipation of potential in a dark place, and (3) light Immediately dissipating the charge by irradiation may be mentioned.

[0003] Conventionally, selenium,
Inorganic photoreceptors having a photosensitive layer mainly containing an inorganic photoconductive compound such as zinc oxide and cadmium sulfide have been widely used. However, they satisfy the above conditions (1) to (3), but are not necessarily satisfactory in heat stability, moisture resistance, durability, and productivity.

In order to overcome the disadvantages of inorganic photoconductors, electrophotographic photoconductors containing various organic photoconductive compounds as main components have been actively developed in recent years. For example, US Pat.
No. 851 discloses a photoreceptor having a charge transport layer containing triallylpyrazolin, and US Pat. No. 3,871,880 discloses a charge generating layer comprising a derivative of perylene pigment and
Photoreceptors comprising a charge transport layer comprising a condensate of propylene and formaldehyde are known.

Further, the photosensitive wavelength range of the electrophotographic photosensitive member can be freely selected according to the kind of the organic photoconductive compound.
As for the substances disclosed in JP-A 1-227754 and JP-A 56-167759, those exhibiting high sensitivity in the visible region are disclosed. In addition, JP-A 57-19567 and JP-A 61-228453 are disclosed. It has been shown that the compounds described in the publication have sensitivity up to the infrared region.

Of these materials, those exhibiting sensitivity in the infrared region are used in laser beam printers (hereinafter abbreviated as LBPs) and LED printers, which have been making remarkable progress in recent years.
The demand frequency is increasing.

Electrophotographic photoreceptors using these organic photoconductive compounds are used as function-separated type photoreceptors in which a charge transport layer and a charge generation layer are laminated in order to satisfy both electrical and mechanical properties. Often done. On the other hand, it is needless to say that the electrophotographic photoreceptor is required to have sensitivity, electrical characteristics, and even optical characteristics according to the electrophotographic process applied.

In particular, in the case of an electrophotographic photosensitive member that is repeatedly used, an external electrical or mechanical force such as corona or direct charging, image exposure, toner development, a transfer process, and surface cleaning is directly applied to the surface of the electrophotographic photosensitive member. Therefore, durability for them is also required.

More specifically, electrical deterioration due to ozone and nitrogen oxides during charging, discharge during charging, mechanical deterioration in which the surface is worn or scratched due to rubbing of a cleaning member, Durability against mechanical deterioration is required.

[0010] The electrical deterioration is particularly problematic in that carriers stay in portions irradiated with light and a potential difference is generated between the portions not irradiated with light and a photo memory.

The mechanical deterioration is different from the inorganic photoreceptor, and the organic photoreceptor, which has many soft materials, is inferior in durability against mechanical deterioration, and it is particularly desired to improve the durability.

Various attempts have been made in the past to satisfy the durability characteristics required for the photosensitive member as described above.

As a resin often used for the surface layer and having good abrasion and electrical properties, attention has been paid to a polycarbonate resin having bisphenol A as a skeleton. However, not all of the above-mentioned problems can be solved. It has the following problems. (1) It has poor solubility and shows good solubility only in a part of halogenated aliphatic hydrocarbons such as dichloromethane and 1.2-dichloroethane. In addition, since these solvents have a low boiling point, these solvents cannot be used. When a photoreceptor is manufactured using the prepared coating solution, the coated surface tends to be whitened. It takes time to control the solid content of the coating liquid. (2) It is partially soluble in solvents other than halogenated aliphatic hydrocarbons in tetrahydrafuran, dioxane, cyclohexanenone or a mixed solvent thereof, but the solution gels in a few days, such as gelation. It is not suitable for photoreceptor production because of poor properties. (3) Even if the above (1) and (2) are improved, solvent cracks are likely to occur in the polycarbonate resin having bisphenol A as a skeleton. (4) In addition, in a conventional polycarbonate resin, a coating formed of the resin does not have lubricity, so that the photosensitive member is easily damaged, and an image defect may occur in a cleaning setting that reduces the abrasion amount of the electrophotographic photosensitive member. In addition, poor cleaning, toner fusion, and the like may occur due to early deterioration of the cleaning blade.

Regarding the solution stability mentioned in the above (1) and (2), a polycarbonate Z resin having a bulky cyclohexylene group as a polymer structural unit is used or copolymerized with bisphenol Z, bisphenol C or the like. It has been solved by

[0015] Solvent cracks are also disclosed in
As disclosed in JP-A-51544 and JP-A-6-75415, silicone-modified polycarbonate,
This can be solved by using an ether-modified polycarbonate. However, compared to conventional polycarbonate resins, these modified polycarbonates have a structure that gives flexibility to internal stress in the polymer in order to prevent solvent cracks,
As a result, there is a disadvantage that the mechanical strength of the polymer body is reduced.

In order to improve the strength, Japanese Patent Application Laid-Open No.
As disclosed in Japanese Patent No. 23630, a polycarbonate resin having an allyl group is crosslinked by heat or energy. However, even in this case, since the charge transporting material is in a low molecular state, a strength surface and cracks are not generated. There was still room for improvement.

Further, in recent years, a direct charging system in which a voltage is applied directly to a charging member and a charge is applied to an electrophotographic photosensitive member as disclosed in JP-A-57-17826 and JP-A-58-40566. Is becoming mainstream.

This is a method in which a roller-shaped charging member made of conductive rubber or the like is brought into direct contact with an electrophotographic photosensitive member to apply an electric charge, and the amount of generated ozone is significantly smaller than that of a scorotron or the like. While the scorotron is wasted because about 80% of the current flowing through the charger flows through the shield, direct charging has the advantage that it is very economical without this waste.

However, direct charging has a drawback that charging stability is very poor because of charging by discharge according to Paschen's rule. As a countermeasure, a so-called AC / DC charging system in which an AC voltage is superimposed on a DC voltage has been devised (JP-A-63-149668).

[0020]

Although the stability during charging is improved by this charging method, the amount of discharge on the surface of the electrophotographic photosensitive member is greatly increased due to the superposition of AC. There is a new disadvantage that the amount of scraping increases, and not only mechanical strength but also electrical strength has been required.

An object of the present invention is to solve the problems of the conventional surface layer, to have a high mechanical strength, a good electric resistance to discharge by direct charging, and a small surface roughness due to durability. An object of the present invention is to provide an electrophotographic photoreceptor which is hardly damaged and from which an image free from image defects can be obtained for a long period of time, a process cartridge having the electrophotographic photoreceptor, and an electrophotographic apparatus.

[0022]

That is, the present invention relates to an electrophotographic photoreceptor having a photosensitive layer on a support, wherein a binder resin for a surface layer of the electrophotographic photoreceptor contains a filler or a compound for imparting elasticity. An electrophotographic photosensitive member characterized by containing the same, a process cartridge having the electrophotographic photosensitive member, and an electrophotographic apparatus.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the Young's modulus of the surface layer of an electrophotographic photosensitive member before adding a filler or a compound for imparting elasticity is 3.0 GPa or more, and the rate of change of the Young's modulus by the addition is 10 GPa. % Is preferable.

In the present invention, as the filler for imparting elasticity, for example, resin particles obtained by a method such as polymerization, pulverization, spray drying or the like in an aqueous or non-dispersed system can be used. The resin may be a homopolymer or a copolymer, and examples of the resin include crosslinked or non-crosslinked resins such as acrylic, polyester, urethane, polyethylene, polypropylene, butadiene, acrylonitrile / butadiene, styrene / butadiene, and silicone having elasticity. Examples include, but are not limited to, crosslinked fine particles. Core-shell type fine particles having an elastic component at the center and a hard component at the outer periphery may be used.

As the compound imparting elasticity, for example, a polymer such as liquid rubber can be used. The polymer may be a homopolymer or a copolymer.Examples of the polymer include liquid polybutadiene, liquid polyacrylonitrile butadiene, liquid polyisoprene, liquid polybutylene, liquid polysulfide, polybutene, polycaprolactone, liquid silicone rubber, and the like. And liquid polyacrylonitrile butadiene. Below, the structural example of the compound is shown,
It is not limited to these.

[0026]

Embedded image (R represents an alkyl group, an aryl group, a hydroxyl group, a carboxyl group, a vinyl group, a glycidyl group, or an amino group which may be substituted.) The binder resin of the surface layer of the electrophotographic photoreceptor has, for example, a straight main chain. Resins consisting of a single bond of chain or cyclic carbon, resins having an ester bond in the main chain, resins having a carbonate bond in the main chain, resins having an ether bond in the main chain, resins having a siloxane bond in the main chain, and the like. Can be Further, it may have a functional group which can be crosslinked by heat or the like. Specific examples of the resin include an acrylic resin, a polyester resin, an epoxy resin, a phenol resin, a polycarbonate resin, a polyarylate resin, a melamine resin, a urethane resin, a fluororesin, a silicone resin, and the like, but are not limited thereto. Absent. These may be used alone or in combination of two or more kinds of repeating units.

The electrophotographic photoreceptor according to the present invention has such characteristics that it has high mechanical strength, good electric resistance against electric discharge caused by direct charging, small surface roughness due to durability and scars. .

In the electrophotographic photoreceptor according to the present invention, by adding a specific filler or compound to the binder resin of the surface layer of the electrophotographic photoreceptor, elasticity is imparted to the surface layer of the electrophotographic photoreceptor, As a result, the external force applied to the electrophotographic photoreceptor in the electrophotographic process is reduced, so that it is considered that the electrophotographic photoreceptor has excellent mechanical strength, has small surface roughness due to durability, and is hardly damaged.

As a result, the durability of the electrophotographic photosensitive member is improved, and a defect-free image can be obtained for a long period of time.

In the electrophotographic photoreceptor of the present invention, the specific filler or compound according to the present invention may be one kind or two or more kinds.

Hereinafter, the structure of the electrophotographic photosensitive member used in the present invention will be described.

The electrophotographic photoreceptor of the present invention may be either a single-layer type in which the photosensitive layer contains a charge transporting material and a charge generating material in the same layer, or a laminated type in which the photosensitive layer is separated into a charge transporting layer and a charge generating layer. Although good, the laminated type is preferable in terms of electrophotographic characteristics.

The conductive substrate to be used only needs to have conductivity, such as metals such as aluminum and stainless steel.
Alternatively, metal, paper, plastic, or the like provided with a conductive layer may be used, and the shape may be a sheet, a cylinder, or the like.

When the image input is a laser beam such as LBP, a conductive layer may be provided for the purpose of preventing interference fringes due to scattering or covering a scratch on the substrate. This can be formed by dispersing conductive powder such as carbon black and metal particles in a binder resin. The thickness of the conductive layer is 5
40 μm, preferably 10 to 30 μm is suitable.

An intermediate layer having an adhesive function is provided thereon. As the material of the intermediate layer, polyamide, polyvinyl alcohol, polyethylene oxide, ethyl cellulose,
Casein, polyurethane, polyether urethane, and the like. These are applied by dissolving in an appropriate solvent. The thickness of the intermediate layer is 0.05 to 5 μm, preferably 0.1 to 5 μm.
3 to 1 μm is appropriate.

The charge generation layer is formed on the intermediate layer.
Examples of the charge generating material used in the present invention include selenium-tellurium, pyrylium, thiapyrylium dyes, phthalocyanine, anthantrone, dibenzpyrenequinone, trisazo, cyanine, disazo, monoazo, indigo, quinacridone, and asymmetric quinocyanine pigments. No. In the case of the function-separated type, the charge generation layer comprises a homogenizer, an ultrasonic dispersion, a ball mill, a vibration ball mill, a sand mill, an attritor, a roll mill, and a liquid collision with the charge generation material together with a binder resin and a solvent in an amount of 0.3 to 4 times. It is formed by dispersing well by a method such as a mold high-speed disperser, applying a dispersion, and drying. The thickness of the charge generation layer is 5 μm
Hereinafter, preferably, 0.1 to 2 μm is appropriate.

The charge transport layer is formed by coating and drying a binder resin containing a filler or compound imparting elasticity according to the present invention and a charge transport material dissolved in a solvent.

The charge transporting materials used include triarylamine compounds, hydrazone compounds, stilbene compounds, pyrazoline compounds, oxazole compounds,
Triarylmethane-based compounds, thiazole-based compounds and the like can be mentioned. The thickness of the charge transport layer is 5 to 40 μm, preferably 15 to 30 μm.

When a protective layer is further provided, it is formed by applying and drying a coating material in which a binder resin mainly containing a filler or a compound for imparting elasticity, a resistance controlling agent, additives and the like are dissolved in a solvent. . In this case, the charge transport layer may not contain the filler or compound imparting elasticity according to the present invention.

FIG. 1 shows a schematic configuration of an electrophotographic apparatus using a process cartridge having the electrophotographic photosensitive member of the present invention.

In FIG. 1, reference numeral 1 denotes a drum-shaped electrophotographic photosensitive member of the present invention, which is driven to rotate around a shaft 2 in a direction of an arrow at a predetermined peripheral speed. The photoreceptor 1 rotates during the rotation process.
The peripheral surface is uniformly charged at a predetermined positive or negative potential by the primary charging means 3, and then, the time-series electricity of target image information output from exposure means (not shown) such as slit exposure or laser beam scanning exposure. The exposure light 4 which has been enhanced and modulated according to the digital image signal is received. Thus, an electrostatic latent image corresponding to the target image information is sequentially formed on the peripheral surface of the photoconductor 1.

The formed electrostatic latent image is then transferred to developing means 5
The toner image thus developed is transferred from a paper supply unit (not shown) between the photoconductor 1 and the transfer unit 6 in synchronization with the rotation of the photoconductor 1 to a transfer material 7 fed and fed. Then, the toner image formed and carried on the surface of the photoconductor 1 is sequentially transferred by the transfer unit 6.

The transfer material 7 to which the toner image has been transferred is separated from the surface of the photoreceptor, introduced into the image fixing means 8 and subjected to image fixing to be printed out as an image formed product (print, copy) outside the apparatus. You.

The surface of the photoreceptor 1 after image transfer is cleaned and cleaned by removing the untransferred toner by the cleaning means 9, and is further subjected to a pre-exposure light 10 from a pre-exposure means (not shown).
Is used for image formation repeatedly after the charge removal processing. When the primary charging unit 3 is a contact charging unit using a charging roller or the like, the pre-exposure is not necessarily required.

In the present invention, of the above-mentioned components such as the electrophotographic photosensitive member 1, the primary charging means 3, the developing means 5, and the cleaning means 9, a plurality of components are integrally connected as a process cartridge. The process cartridge may be configured to be detachable from a main body of an electrophotographic apparatus such as a copying machine or a laser beam printer. For example, at least one of the primary charging unit 3, the developing unit 5, and the cleaning unit 9 is integrally supported together with the photoreceptor 1 to form a cartridge, and is detachably attached to the apparatus main body using a guide unit such as a rail 12 of the apparatus main body. Process cartridge 1
It can be 1.

When the electrophotographic apparatus is a copying machine or a printer, the exposure light 4 is reflected light or transmitted light from the original, or the original is read by a sensor, converted into a signal, and a laser beam is emitted in accordance with the signal. Beam scanning, LED
Light emitted by driving the array, driving the liquid crystal shutter array, and the like.

The electrophotographic photosensitive member of the present invention can be used not only for an electrophotographic copying machine but also for a laser beam printer,
It can be widely used in electrophotographic applications such as CRT printers, LED printers, liquid crystal printers, and laser plate making.

[0048]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The following is a description of embodiments.

(Example 1) An aluminum cylinder having a diameter of 30 mm and a diameter of 254 mm was used as a support, and a coating composed of the following materials was applied to the support by dipping and heat-cured at 140 ° C for 30 minutes to form a 15 μm conductive layer. Was formed.

Conductive pigment: 10 parts of barium sulfate treated with SnO ₂ coating Pigment for resistance control: 2 parts of titanium oxide Binder resin: 6 parts of phenol resin Leveling material: 0.001 part of silicone oil Solvent: methanol, methoxypropanol 0.2 / 0.8 20 parts Next, 3 parts of N-methoxymethylated nylon and 3 parts of copolymerized nylon were added thereto with 65 parts of methanol and 3 parts of n-butanol.
The solution dissolved in 0 parts of the mixed solvent was applied by dipping.
An intermediate layer of 5 μm was formed.

Next, the diffraction angles 2θ ± 0.2 ° in the X-ray diffraction spectrum of CuKα are 9.0 °, 14.2 °, 2
4 parts of oxytitanium phthalocyanine having strong peaks at 3.9 ° and 27.1 °, 2 parts of polyvinyl butyral (trade name: Eslec BM2, manufactured by Sekisui Chemical) and 60 parts of cyclohexanone were mixed with a sand mill using φ1 mm glass beads. Ethyl acetate 1 after time dispersion
By adding 00 parts, a dispersion for a charge generation layer was prepared. This was applied by dipping to form a 0.2 μm charge generation layer.

Next, 7 parts of an example compound having the following structure

[0053]

Embedded image And 1 part of a charge transport material compound having the following structure

[0054]

Embedded image And 9 parts of polycarbonate Z resin (manufactured by Mitsubishi Gas Chemical Co., viscosity average molecular weight: 40,000) and 1 part of acrylic rubber particles (Staphyroid IM, manufactured by Takeda Pharmaceutical Co., Ltd.) were dissolved in a mixed solvent of 30 parts of monochlorobenzene and 30 parts of dichloromethane.

This paint was applied by dipping and dried at 120 ° C. for 2 hours to form a 25 μm charge transport layer.

Next, the evaluation will be described.

First, using a Fisher Scope H-100V manufactured by Fisher Instruments Co., Ltd.
The Young's modulus of the coating film was measured.

The measurement conditions at this time were room temperature and normal humidity [22.5
C., 50%], the maximum load was 100 mN, and the load time was 20 seconds.

The device is a Hewlett-Packard LBP
"Laser jet 4plus" (process speed 7
1 mm / sec). In the remodeling, primary charging was controlled by constant current control and constant voltage control. The produced electrophotographic photosensitive member was subjected to paper passing durability at 23 ° C. and 80% RH with this apparatus. The sequence was an intermittent mode in which the printing was stopped once for each print. When the toner ran out, it was replenished. When 7,000 sheets were durable, the shaved film thickness and the maximum scratch depth were measured.

Table 1 shows the results.

Example 2 A liquid polymer (Hiker VTB) was used instead of the acrylic rubber particles in the charge transport layer of Example 1.
NX, manufactured by Ube Industries, Ltd.), and an electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1.

(Example 3) Acrylic rubber particles of the charge transport layer of Example 1 (Staphyroid IM, manufactured by Takeda Pharmaceutical Co., Ltd.)
An electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 1, except that acrylic rubber particles (Staphyroid AC, manufactured by Takeda Pharmaceutical Co., Ltd.) were used in place of the above.

Example 4 Acrylic rubber particles of the charge transport layer of Example 1 (Staphyroid IM, manufactured by Takeda Pharmaceutical Co., Ltd.)
An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 except that a liquid polymer (Poly-bd, manufactured by Idemitsu Petrochemical) was used instead of

Example 5 A polyarylate resin (U) was used instead of the polycarbonate Z resin of the charge transport layer of Example 1.
An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 except that a polymer (manufactured by Unitika) was used.

Example 6 Instead of the polycarbonate Z resin of the charge transport layer of Example 2, a polyarylate resin (U
An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 2 except that a polymer (manufactured by Unitika) was used.

Example 7 In the charge transport layer of Example 1, 7 parts of an example compound of a charge transport material having the following structure

[0067]

Embedded image And 1 part of a charge transport material compound having the following structure

[0068]

Embedded image And 8 parts of polycarbonate Z resin (manufactured by Mitsubishi Gas Chemical Co., viscosity average molecular weight: 40,000) and 2 parts of acrylic rubber particles (staphyloid IM, manufactured by Takeda Pharmaceutical) dissolved in a mixed solvent of 30 parts of monochlorobenzene and 30 parts of dichloromethane An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 except for using the same.

Example 8 Instead of the polycarbonate Z resin of the charge transport layer of Example 7, a polyarylate resin (U
An electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 7, except that a liquid polymer (Hiker VTBNX, manufactured by Ube Industries) was used instead of the acrylic rubber particles. Table 1 shows the above results.

Example 9 Disazo pigment 4 having the following structural formula
Parts, 2 parts of polyvinyl butyral (butyral conversion ratio: 68%, weight average molecular weight: 24000) and 34 parts of cyclohexanone were dispersed by a sand mill using Φ1 mm glass beads for 12 hours, and then 60 parts of tetrahydrofuran was added thereto to coat the charge generating layer. The liquid was adjusted.

[0071]

Embedded image This is applied by a dipping method and dried at 80 ° C. for 20 minutes to form a film having a thickness of 0.1 mm.
An electrophotographic photosensitive member was prepared in the same manner as in Example 1, except that the charge generation layer was 15 μm.

This photoreceptor is used with a Canon copier NP60
The film was mounted on a 35-model remodeling machine (remodeling the cleaning blade pressure to 1.2 times), and the film thickness, maximum scratch depth and image evaluation after 30,000-sheet durability were evaluated. Table 2 shows the results.

Example 10 A liquid polymer (Hiker VT) was used instead of the acrylic rubber particles in the charge transport layer of Example 9.
An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 9 except that BNX (manufactured by Ube Industries) was used.

Example 11 Instead of the acrylic rubber particles (Staphyloid IM, manufactured by Takeda Pharmaceutical Co., Ltd.) of the charge transport layer of Example 9, acrylic rubber particles (Staphyloid A)
C, manufactured by Takeda Pharmaceutical Co., Ltd.), and an electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 9.

Example 12 Example 12 was repeated except that a liquid polymer (Poly-bd, manufactured by Idemitsu Petrochemical) was used instead of the acrylic rubber particles (Staphyroid IM, manufactured by Takeda Chemical Industries) of the charge transport layer of Example 9. An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 9.

Example 13 An electrophotographic photosensitive member was produced in the same manner as in Example 9 except that a polyarylate resin (U polymer, manufactured by Unitika) was used in place of the polycarbonate Z resin of the charge transport layer of Example 9. evaluated.

(Example 14) Example 10 was repeated except that a polyarylate resin (U polymer, manufactured by Unitika) was used in place of the polycarbonate Z resin of the charge transport layer of Example 10.
An electrophotographic photoreceptor was prepared and evaluated in the same manner as described above.

(Example 15) The charge transport layer of Example 9
Example of charge transport material having the following structure: 7 parts

[0079]

Embedded image And 1 part of a charge transport material compound having the following structure

[0080]

Embedded image And 8 parts of polycarbonate Z resin (manufactured by Mitsubishi Gas Chemical Co., viscosity average molecular weight: 40,000) and 2 parts of acrylic rubber particles (staphyloid IM, manufactured by Takeda Pharmaceutical) dissolved in a mixed solvent of 30 parts of monochlorobenzene and 30 parts of dichloromethane An electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 9 except for using the same.

Example 16 A polyarylate resin (U polymer, manufactured by Unitika) was used instead of the polycarbonate Z resin of the charge transport layer of Example 15, and a liquid polymer (Hiker VTBNX, manufactured by Ube Industries) was used instead of the acrylic rubber particles. An electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 15 except for using. Table 2 shows the above results.

[0082] (Comparative Example 1) An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1, except that the charge transport layer was formed by the following procedure.

<Procedure for Producing a Charge Transporting Layer> 7 parts of a compound of a charge transporting material having the following structure

[0084]

Embedded image And 1 part of a charge transport material compound having the following structure

[0085]

Embedded image And 10 parts of a polycarbonate Z resin (manufactured by Mitsubishi Gas Chemical, viscosity average molecular weight: 40,000) were dissolved in a mixed solvent of 30 parts of monochlorobenzene and 30 parts of dichloromethane.

This paint was applied by a dipping method and dried at 120 ° C. for 2 hours to form a 25 μm charge transport layer.

(Comparative Example 2) Instead of the polycarbonate Z resin of the charge transport layer of Comparative Example 1, a polyarylate resin (U
An electrophotographic photoreceptor was prepared and evaluated in the same manner as in Comparative Example 1 except that a polymer (manufactured by Unitika) was used.

Comparative Example 3 An electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 9 except that the charge transport layer was formed in the same manner as in Comparative Example 1.

Comparative Example 4 An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Comparative Example 3 except that the charge transport layer was formed in the same manner as in Comparative Example 2.

Table 3 shows the results of evaluation of the electrophotographic photosensitive members of Comparative Examples 1 and 2, and Table 4 shows the results of evaluation of the electrophotographic photosensitive members of Comparative Examples 3 and 4.

[0091]

[0092]

According to the present invention, it is possible to provide an electrophotographic photoreceptor having high mechanical strength, good electric resistance against electric discharge caused by direct charging, and being hardly damaged by durability.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a schematic configuration of an electrophotographic apparatus using a process cartridge having an electrophotographic photosensitive member of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoreceptor 2 axis 3 Charging means 4 Exposure light 5 Developing means 6 Transfer means 7 Transfer material 8 Fixing means 9 Cleaning means 10 Pre-exposure light 11 Process cartridge 12 Rail

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Takakazu Tanaka 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 2H068 AA04 AA08 AA14 AA28 AA35 AA37 BB09 BB19 BB20 BB33 BB65 FA27

Claims (9)

[Claims] 1. An electrophotographic photosensitive member having a photosensitive layer on a support, characterized in that the binder resin of the surface layer of the electrophotographic photosensitive member contains a filler or a compound which imparts elasticity by being added. Electrophotographic photoreceptor. 2. The Young's modulus of a surface layer of an electrophotographic photosensitive member before adding a filler or a compound for imparting elasticity is 3.
0 GPa or more, the rate of change of Young's modulus by addition is 10
%. 3. The electrophotographic photoreceptor according to claim 1, wherein the filler contained in the binder resin of the surface layer is resin fine particles. 4. The electrophotographic photosensitive member according to claim 1, wherein the compound contained in the binder resin of the surface layer is a liquid rubber. 5. The electrophotographic photoconductor according to claim 1, wherein the compound imparting elasticity to be contained in the binder resin of the surface layer is a silicone compound. 6. The fine resin particles contained in the binder resin of the surface layer are elastic acrylic resin fine particles.
2. The electrophotographic photoreceptor of claim 1. 7. The electrophotographic photoreceptor according to claim 5, wherein the resin fine particles contained in the binder resin of the surface layer are elastic acrylic fine particles having a core-shell double structure. 8. An electrophotographic photosensitive member according to claim 1, a charging unit, a developing unit, and a cleaning unit, wherein at least one unit selected from the group is integrally supported and detachably attached to an electrophotographic apparatus main body. A process cartridge. 9. An electrophotographic apparatus comprising the electrophotographic photosensitive member according to claim 1, a charging unit, an image exposing unit, a developing unit, and a transferring unit.