JP2001201880A - Electrophotographic photosensitive member, and process cartridge and electrophotographic apparatus provided with the electrophotographic photosensitive member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor which has high mechanical strength while having solvent crack resistance, has good electric resistance by direct charging, and is easy to manufacture. SOLUTION: In an electrophotographic photosensitive member having a conductive support and a photosensitive layer, the surface layer of the electrophotographic photosensitive member has a polyarylate resin having a structural unit represented by the following formula (1) and a polyarylate resin represented by the following formula (2): An electrophotographic photosensitive member comprising a hydrazone compound represented by the formula: Embedded image (Wherein, X is —CR ³ R ⁴ — (where R ³ and R ⁴ are each independently a hydrogen atom, an alkyl group, etc.), a cycloalkylidene group, etc.), and R ¹ and R ² are each independently A and b each independently represent 0,
-4. ) (In the formula, Y ¹ and Y ² are each independently an optionally substituted alkyl group or the like. Y ³ and Y ⁴ are each independently a hydrogen atom or an alkyl group.)

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member, a process cartridge having the electrophotographic photosensitive member, and an electrophotographic apparatus, and more particularly, to an electrophotographic photosensitive member having a surface layer containing a specific resin and a charge transport material. And a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member.

[0002]

2. Description of the Related Art As described in U.S. Pat. No. 2,976,691, an electrophotographic method changes electric resistance according to the amount of light received during image exposure, and has an insulating property in a dark place. This is performed using a photoconductive material comprising a support coated with a substance. The basic characteristics required of an electrophotographic photoreceptor using this photoconductive material include (1)
That it can be charged to an appropriate potential in a dark place, (2) there is little dissipation of electric charge in a dark place, and (3) that the charge can be quickly dissipated by light irradiation.

Hitherto, as an electrophotographic photosensitive member, an inorganic photosensitive member having a photosensitive layer mainly composed of an inorganic photoconductive material such as selenium, zinc oxide and cadmium sulfide has been widely used. However, they satisfy the above conditions (1) to (3), but are not always satisfactory in heat stability, moisture resistance, durability, productivity, and the like.

In order to overcome the disadvantages of inorganic photoreceptors, electrophotographic photoreceptors containing various organic photoconductive compounds as main components have been actively developed in recent years. For example, US Patent 38
Japanese Patent No. 37851 discloses a photoreceptor having a charge transport layer containing triallyl pyrazoline, and US Pat. No. 3,871,880 discloses a photoreceptor having a charge generation layer comprising a derivative of a perylene pigment.
And a photoreceptor comprising a charge transport layer comprising a condensate of propylene and formaldehyde.

Further, the photosensitive wavelength range of the electrophotographic photosensitive member can be freely selected depending on the kind of the organic photoconductive compound.
The substances disclosed in JP-A-61-272754 and JP-A-56-167759 exhibit high sensitivity in the visible region. JP-A-57-195
It is described that the compounds disclosed in JP-B-76 and JP-A-61-228453 have sensitivity up to the infrared region.

[0006] Among these materials, those which show sensitivity in the infrared region are laser beam printers, which have made remarkable progress in recent years.
(Hereinafter abbreviated as LBP) and LED printers, and the demand frequency is increasing.

The electrophotographic photoreceptor using these organic photoconductive compounds is a function-separated type photoreceptor having a charge transport layer and a charge generation layer laminated in order to satisfy both electrical and mechanical properties. Often used as. On the other hand, as a matter of course, the electrophotographic photoreceptor is required to have sensitivity, electrical characteristics, and optical characteristics according to the applied electrophotographic process.

In particular, in the case of an electrophotographic photoreceptor that is repeatedly used, external electric and mechanical forces such as corona or direct charging, image exposure, toner development, a transfer process, and surface cleaning are directly applied to the surface of the electrophotographic photoreceptor. Since they are added, their durability is also required.

Specifically, the surface is worn or scratched due to electrical deterioration due to ozone and nitrogen oxide during charging, electrical deterioration due to discharging during charging, and rubbing of the cleaning member. There is a demand for durability against mechanical deterioration.

[0010] Regarding the electrical deterioration, a phenomenon that a carrier stays in a portion irradiated with light and a potential difference is generated between a portion not irradiated with light is a particularly problematic phenomenon, which occurs as a photo memory.

Regarding mechanical deterioration, organic photoreceptors, which are often materially soft unlike inorganic photoreceptors, are inferior in durability against mechanical deterioration. Therefore, improvement in durability is particularly desired.

Various attempts have been made to satisfy the durability characteristics required for the photoreceptor as described above.

As a resin often used for the surface layer and having good abrasion resistance and electric characteristics, 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. Has the following problems.

(1) Poor solubility, showing good solubility only in a part of halogenated aliphatic hydrocarbons such as dichloromethane and 1,2-dichloroethane, and since these solvents have a low boiling point, When a photoreceptor is manufactured using a coating solution prepared with these solvents, the coated surface tends to be whitened.
It takes time to control the solid content of the coating liquid.

(2) Solvents other than halogenated aliphatic hydrocarbons are partially soluble in tetrahydrafuran, dioxane, cyclohexanone or a mixed solvent thereof, but the solution can be prepared within a few days. It is not suitable for photoreceptor production due to poor aging properties such as gelation.

(3) Even if the above (1) and (2) are further improved, solvent cracks are liable to occur in the polycarbonate resin having bisphenol A as a skeleton.

(4) In addition, in the case of the conventional polycarbonate resin, since the film formed of the resin has no lubricity,
The photoreceptor is easily damaged, and cleaning settings that reduce the abrasion loss of the electrophotographic photoreceptor may cause image defects, cleaning failure due to early deterioration of the cleaning blade, toner fusion, etc. There is.

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

[0019] Solvent cracks can also be solved by using a silicon-modified polycarbonate and an ether-modified polycarbonate as disclosed in JP-A-6-51544 and JP-A-6-75415. is there. However, these modified polycarbonates have a structure that has flexibility against internal stress in the polymer as a measure against solvent cracks compared to conventional polycarbonate resins,
There is a disadvantage that the mechanical strength of the polymer body is reduced.

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 a conductive rubber or the like is brought into direct contact with an electrophotographic photosensitive member to apply a charge, and (a) compared with a scorotron or the like,
The amount of generated ozone is extremely small. (B) Scorotron is wasted because about 80% of the current flowing to the charger is wasted because it flows to the shield, whereas direct charging has no waste and is very economical. There are advantages.

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).

Although the charging system improved the stability during charging, the amount of discharge on the surface of the electrophotographic photosensitive member was greatly increased due to the superposition of AC, and the shaving amount of the electrophotographic photosensitive member was reduced. There is a new drawback that the electrophotographic photosensitive member is increased in electric strength as well as mechanical strength.

In order to improve the mechanical strength, see JP-A-57-3
In JP 0841, a polyarylate resin is used in place of the polycarbonate resin. By using a polyarylate resin, a product excellent in mechanical strength can be obtained, but it is found that solvent cracking and electric strength alone are not practically satisfactory.

JP-A-2-226160 discloses a photoreceptor having a charge transport layer containing a hydrazone compound. The hydrazone compound has good compatibility with the binder, and the photoreceptor using the same has high sensitivity. However, it is found that the hydrazone compound alone is not satisfactory in practical use in solvent cracks, mechanical strength and electric strength.

[0026]

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of a conventional electrophotographic photoreceptor having a polycarbonate or polyarylate resin as a surface layer, and to achieve solvent crack resistance. An object of the present invention is to provide an electrophotographic photoreceptor having high mechanical strength, good electrical resistance due to direct charging (AC superimposed charging), and easy to manufacture. It is a further object of the present invention to provide a process cartridge and an electrophotographic apparatus provided with the electrophotographic photosensitive member.

[0027]

Means for Solving the Problems The present inventors have found that the above object can be achieved by combining a specific resin and a specific charge transporting material, and have completed the present invention.

That is, the present invention provides an electrophotographic photoreceptor having a conductive support and a photosensitive layer, wherein the surface layer of the electrophotographic photoreceptor has a polymer having a structural unit represented by the following formula (1): An electrophotographic photoreceptor characterized by containing a charge transport material represented by the formula (2).

[0029]

Embedded image (Wherein X is —CR ³ R ⁴ — (wherein R ³ and R ⁴ are each independently a hydrogen atom, a trifluoromethyl group, an alkyl group, or an aryl group), or an optionally substituted cycloalkylidene group , Α, ω-alkylene group, single bond,-
O -, - S -, - SO-, or -SO ₂ - is. R ¹ and R ² are each independently a hydrogen atom, a halogen atom, an alkyl group or an aryl group which may be substituted, and a and b are each independently an integer of 0 to 4. )

[0030]

Embedded image (Wherein Y ¹ and Y ² each independently represent an alkyl group, alkenyl group, aralkyl group, aryl group,
Or a heterocyclic group. Y ³ and Y ⁴ are each independently a hydrogen atom, an alkyl group, an alkoxy group, or a halogen atom. )

In the electrophotographic photosensitive member of the present invention, the structural unit represented by the above formula (1) is preferably one represented by the following formula (3).

[0032]

Embedded image

Further, the present invention provides a process cartridge and an electrophotographic apparatus having the above electrophotographic photosensitive member. That is, the above-mentioned electrophotographic photoreceptor, a process cartridge which integrally supports at least one means selected from the group consisting of a charging means, a developing means and a cleaning means, and is detachable from an electrophotographic apparatus main body, and Provided is an electrophotographic apparatus including a photographic photosensitive member, a charging unit, an image exposure unit, a developing unit, and a transfer unit.

In the process cartridge and the electrophotographic apparatus of the present invention, the charging means is preferably a contact charging means.

The electrophotographic photoreceptor according to the present invention has a particularly excellent solvent cracking resistance by selecting a combination of the above-mentioned specific resin and charge transporting material as the resin forming the surface layer and the charge transporting material. It has both good mechanical strength and electrical resistance in direct charging (especially AC superimposed charging), and has good electrophotographic characteristics.

[0036]

BEST MODE FOR CARRYING OUT THE INVENTION The surface layer of the electrophotographic photoreceptor of the present invention comprises a polymer having a structural unit represented by the above formula (1) (hereinafter also referred to as a polyarylate resin used in the present invention).
It contains.

In the formula (1), X represents —CR ³ R ⁴ —
(Wherein R ³ and R ⁴ are each independently a hydrogen atom, a trifluoromethyl group, an alkyl group, or an aryl group), an optionally substituted cycloalkylidene group,
ω-alkylene group, single bond, -O-, -S-, -SO
— Or —SO ₂ —. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group. As the aryl group, a phenyl group, a naphthyl group,
Examples include an anthryl group and a phenanthryl group. As the cycloalkylidene group, a cyclohexylidene group,
And a cyclopentylidene group. Examples of the substituent which the cycloalkylidene group may have include a methyl group and an ethyl group. Substitution of a cycloalkylidene group also includes forming a fused ring with one or more benzenes. Examples of the group forming such a condensed ring include a 9-fluorenylidene group. α, ω
-Examples of the alkylene group include an ethylene group and a propylene group.

In the formula (1), R ¹ and R ² are each independently a hydrogen atom, a halogen atom, an alkyl group or an aryl group which may be substituted, and a and b are each independently 0 to 4 It is an integer. Examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group. Examples of the aryl group include a phenyl group and a naphthyl group. Examples of the substituent which the alkyl group may have include the above-described halogen atoms and aryl groups. Examples of the substituent which the aryl group may have include the halogen atoms described above. When a is 2 or more, each R ¹ may be the same or different. When b is 2 or more, each R ² may be the same or different.

In the formula (1), the positions of the two carboxyl groups sandwiching the benzene ring are preferably a mixture of the 1- and 4-positions and the 1- and 2-positions. The ratio to the structural units at the 1-position and 2-position is usually from 7: 3 to 3: 7, preferably about 1: 1.

Specific examples of the structural unit represented by the formula (1) are shown in Tables 1 to 3, but are not limited thereto.

[0041]

[Table 1]

[0042]

[Table 2]

[0043]

[Table 3]

The polyarylate resin used in the present invention may be a polymer in which the structural units represented by the formula (1) are the same, or a polymer composed of two or more different structural units represented by the formula (1). May be used.

Preferred examples of the structural unit include structural unit examples 1, 2 and 7, and in the case of a polymer having the same structural unit, the polymer comprising structural unit example 1 is particularly preferable. In the case of a copolymer composed of two or more different types of structural units represented by the formula (1), structural unit example 1
And a copolymer comprising Structural Unit Example 2 is particularly preferable.

The weight average molecular weight of the polyarylate resin used in the present invention is usually 20,000 to 60,000, preferably 35,000 to 50,000.

The polyarylate resin used in the present invention is in a range that does not reduce the effects obtained in the present invention (improvement in solvent crack resistance, mechanical strength, electric resistance and the like of a photoreceptor having a surface layer containing the same). If present, it may have a structural unit other than the structural unit represented by the formula (1). Normally, the constitutional unit represented by the formula (1) is 50 mol% or more of all constitutional units (in the case of a plurality of kinds of the constitutional units represented by the formula (1), in total).

The polyarylate resin used in the present invention may be used alone or as a mixture of two or more.

The polymer having a constitutional unit represented by the formula (1) used in the present invention is obtained by converting a bisphenol represented by the following formula (4) into terephthalic acid chloride and isophthalic acid chloride in order to increase the solubility. Can be obtained by interfacial polymerization performed by stirring in a solvent / water system under an alkali with a mixture of the products.

[0050]

Embedded image (Wherein X is —CR ³ R ⁴ — (wherein R ³ and R ⁴ are each independently a hydrogen atom, a trifluoromethyl group, an alkyl group, or an aryl group), or an optionally substituted cycloalkylidene group , Α, ω-alkylene group, single bond,-
O -, - S -, - SO-, or -SO ₂ - is. R ¹ and R ² are each independently a hydrogen atom, a halogen atom, an alkyl group or an aryl group which may be substituted, and a and b are each independently an integer of 0 to 4. )

The molar ratio of the sum of terephthalic acid chloride and isophthalic acid chloride to bisphenol is usually about 1: 1. The ratio between terephthalic acid chloride and isophthalic acid chloride is determined in consideration of the solubility of the polymer to be synthesized. It should be noted that if any of the chlorides is 30 mol% or less, the solubility of the synthesized polymer is extremely reduced, so it is necessary to pay attention to the solubility. Usually, the synthesis is preferably performed at a ratio of 1/1.

The polyarylate resin used in the present invention can be obtained as a commercially available polyarylate resin.

The surface layer of the electrophotographic photoreceptor of the present invention also contains a charge transporting material represented by the above formula (2) (hereinafter also referred to as a hydrazone compound used in the present invention).

In the formula (2), Y ¹ and Y ² are each independently an optionally substituted alkyl group, alkenyl group, aralkyl group, aryl group or heterocyclic group. Examples of the alkyl group include a methyl group, an ethyl group, and a propyl group. Examples of the alkenyl group include a propenyl group and a butenyl group. Examples of the aralkyl group include a benzyl group and a phenethyl group. Examples of the aryl group include a phenyl group and a naphthyl group.
Examples of the heterocyclic group include a 6-membered or 5-membered ring group having N, O or S, more specifically, a pyridyl group, a furyl group, a thienyl group and the like. Examples of the substituent include an alkyl group, an alkoxy group such as a methoxy group and an ethoxy group, and a halogen atom such as a fluorine atom, a chlorine atom, and a bromine atom.

In the formula (2), Y ³ and Y ⁴ are each independently a hydrogen atom, an alkyl group, an alkoxy group, or a halogen atom. Examples of the alkyl group include a methyl group, an ethyl group, and a propyl group. Examples of the alkoxy group include a methoxy group and an ethoxy group. Examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom.

The two hydrazone structure-containing moieties bonded to the nitrogen atom bonded to Y ¹ may be the same or different.

Hereinafter, specific examples of the charge transporting material represented by the formula (2) will be shown, but the invention is not limited thereto.

[0058]

Embedded image

[0059]

Embedded image

[0060]

Embedded image

The hydrazone compounds used in the present invention may be used alone or as a mixture of two or more.

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

The electrophotographic photoreceptor of the present invention may be 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 charge transporting layer and the charge generating layer are separated. Although good, the lamination type is preferable in terms of electrophotographic characteristics. The surface layer of the electrophotographic photoreceptor of the present invention is a layer which receives an electric and mechanical external force by charging and cleaning.
Therefore, in the case of a single layer type, the surface layer becomes a layer containing a charge transporting material and a charge generating material, and in the case of a multilayer type, it usually becomes a charge transporting layer.

The surface layer usually contains a binder resin effective amount of the polyarylate resin used in the present invention and a charge transport effective amount of the hydrazone compound used in the present invention. Specifically, the surface layer usually contains 30 to 70% by mass of the polyarylate resin used in the present invention, and 30 to 70% by mass.
Contains 70% by mass of a hydrazone compound used in the present invention. The polyarylate resin and the hydrazone compound may be used as long as the effects obtained in the present invention (improvements in the solvent crack resistance, mechanical strength, and electrical resistance of a photoreceptor having a surface layer containing the same) are not reduced. It is also possible to use a mixture with other known binder resins and other known charge transport substances, respectively.

The structure other than the surface layer of the electrophotographic photosensitive member of the present invention can be the same as that of the conventional electrophotographic photosensitive member.

The conductive support to be used may be any one having conductivity, such as metal such as aluminum or stainless steel, or metal provided with a conductive layer, paper, plastic, or the like. And 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 damage on the substrate. The conductive layer 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 usually 5 to 40 μm, preferably 10 to 30 μm.
μm is appropriate.

An intermediate layer having an adhesive function may be provided on the conductive layer. Examples of the material of the intermediate layer include polyamide, polyvinyl alcohol, polyethylene oxide, ethyl cellulose, casein, polyurethane, and polyether urethane. These are applied by dissolving in an appropriate solvent. The thickness of the intermediate layer is usually 0.05 to 5 μm.
m, preferably 0.3 to 1 μm.

In the case of the lamination type (function separation type), a charge generation layer is formed on a conductive support (in some cases, a conductive layer or an intermediate layer). As the charge generating substance used in the present invention, selenium-tellurium, pyrylium, thiapyrylium-based dye, phthalocyanine, anthantrone, dibenzpyrenequinone, trisazo, cyanine, disazo, monoazo, indigo, quinacridone, asymmetric quinocyanine-based pigments. No. The charge generating layer is a homogenizer, an ultrasonic dispersion, a ball mill, a vibration ball mill, and the charge generating substance together with a binder resin and a solvent in an amount of 0.3 to 4 times.
It is well dispersed by a method such as a sand mill, an attritor, a roll mill, and a liquid collision type high-speed disperser, and is formed by applying and drying the dispersion. The thickness of the charge generation layer is usually 5 μm
Hereinafter, preferably, 0.1 to 2 μm is appropriate.

The charge transporting layer is formed by applying and drying a coating material in which a polyarylate resin used in the present invention and a hydrazone compound used in the present invention are dissolved in a solvent.
The solvent used, the conditions for coating and drying, and the like may be the same as those in the conventional case of forming a charge transport layer using a polyarylate resin as a binder resin. The hydrazone compound is usually combined with 0.5 to 2 times the amount of the polyarylate resin. The thickness of the charge transport layer is usually 5 to 4
0 μm, preferably 15 to 30 μm is suitable.

In the case of a single layer type, a photosensitive layer containing a charge generating material and a charge transporting material is formed on a conductive support (in some cases, a conductive layer or an intermediate layer). This photosensitive layer
Hydrazone compound used in the present invention as a charge transport material,
It can be formed in the same manner as a conventional single-layer type photosensitive layer except that the polyarylate resin used in the present invention is used as a binder resin. The thickness of the photosensitive layer is usually 10 to 50 μm.
m, preferably 15 to 30 μm.

Known additives such as an antioxidant, an ultraviolet absorber and a plasticizer can be further added to the surface layer, if necessary.

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 T printers, LED printers, liquid crystal printers, and laser plate making.

The configuration of the process cartridge and the electrophotographic apparatus of the present invention may be the same as the configuration of the conventional process cartridge and the electrophotographic apparatus except that the electrophotographic photoconductor of the present invention is used as the electrophotographic photoconductor.

The electrophotographic apparatus of the present invention comprises at least an electrophotographic photosensitive member, a charging means for uniformly charging the surface of the photosensitive member, and a method for partially irradiating the charged photosensitive member surface with light. Image exposure means for removing an electrostatic charge to form an electrostatic latent image, developing means for attaching toner to the latent image to form a toner image, and transfer means for transferring the toner image to a transfer material such as recording paper Is provided. The electrophotographic apparatus of the present invention further includes a charge removing means for removing charge on the surface of the photoreceptor, a cleaning means for removing toner and the like adhering to the surface of the photosensitive member, and a fixing means for fixing the transferred toner image to the transfer material. You may. These components are combined so that an electrophotographic process is performed.

The process cartridge of the present invention integrally supports the electrophotographic photosensitive member of the present invention and at least one means selected from the group consisting of a charging means, a developing means and a cleaning means, and is attached to and detached from the main body of the electrophotographic apparatus. It is configured as possible. The electrophotographic main body includes other means not included in the process cartridge and necessary for performing the electrophotographic process.

Since the electrophotographic photosensitive member of the present invention has excellent electric resistance against direct charging, the charging means is preferably a contact charging means such as a charging roller.

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

In FIG. 1, reference numeral 1 denotes a cylindrical (drum) -shaped electrophotographic photosensitive member of the present invention, which is rotated around an axis 2 in a direction indicated by an arrow at a predetermined peripheral speed. In the rotation process, the photosensitive member 1 is uniformly charged with a predetermined positive or negative potential on its peripheral surface by the charging means 3, and then the image from an image exposure means (not shown) such as a slit exposure or a laser beam scanning exposure. The exposure light 4 is received. Thus, an electrostatic latent image 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-developed image developed by the above-described process is transferred to a transfer material 7 fed out of a feeding unit (not shown) between the photoconductor 1 and the transfer unit 6 in synchronization with the rotation of the photoconductor 1 and fed. The image is sequentially transferred by the transfer unit 6.

The transfer material 7 having received the image transfer is separated from the photoreceptor surface, introduced into the image fixing means 8 and subjected to image fixing, and is discharged out of the apparatus as a copy.

The surface of the photoreceptor 1 after the image transfer is cleaned and cleaned by removing the untransferred toner by the cleaning means 9, and further neutralized by the pre-exposure light 10 from the pre-exposure (static elimination) means (not shown). After being processed, it is used repeatedly for imaging. When the 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, the above-described electrophotographic photosensitive member 1 and at least one of the components such as the charging means 3, the developing means 5 and the cleaning means 9 are integrally connected as a process cartridge. This process cartridge may be configured to be detachable from an electrophotographic main body such as a copying machine or a laser beam printer.
For example, the charging unit 3, the developing unit 5 and the cleaning unit 9 are integrally supported together with the photoreceptor 1 to form a cartridge, and the process cartridge 11 is detachable from the apparatus main body using a guide unit such as a rail 12 of the apparatus main body. be able to.

[0084]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The following is a description of embodiments. In the examples, “parts” are parts by mass unless otherwise specified.

[0085]

Examples 1 to 18 An Al cylinder having a diameter of 30 mm and a width of 254 mm was used as a support, and a coating composed of the following materials was applied to the support by a dipping method. A 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 (v / v) = 0.2 / 0.8) 20 copies

Next, a solution prepared by dissolving 3 parts of N-methoxymethylated nylon and 3 parts of copolymerized nylon in a mixed solvent of 65 parts of methanol and 30 parts of n-butanol was applied onto the conductive layer by dipping. A 0.5 μm intermediate layer was formed.

Next, in the X-ray diffraction spectrum of CuKα, the diffraction angle 2θ soil 0.2 ° was 9.0 °, 14.2 °, 2 °
4 parts of titanyl phthalocyanine (TiOPc) having strong peaks at 3.9 ° and 27.1 °, polyvinyl butyral (trade name: Eslec BM2, manufactured by Sekisui Chemical) 2
And 60 parts of cyclohexanone were dispersed in a sand mill using φ1 mm glass beads for 4 hours, and then 100 parts of ethyl acetate was added to prepare a dispersion for a charge generation layer. This is applied by dipping method, and the thickness is 0.3μm
Was formed.

Next, 10 parts of the charge transport material shown in Table 4 and 10 parts of the polymer shown in Table 5 were dissolved in a mixed solvent of 30 parts of monochlorobenzene and 70 parts of dichloromethane. This paint is applied by a dipping method and dried at 120 ° C. for 3 hours.
A charge transport layer having a thickness of 25 μm was formed.

Various polymers (polymers) shown in Table 5 were produced as follows. Biphenol having the structure of the biphenol-derived part in the structural unit ((in the case of plural, total)
0.01 mol), sodium hydroxide (0.8 g) and tetramethylammonium chloride (1 g) in water 100
It was put into a 1 L mixer together with the one dissolved in ml. To this, a solution of terephthalic acid chloride (0.005 mol) and isophthalic acid chloride (0.005 mol) dissolved in 1,2-dichloroethane (30 ml) was added with stirring, and the mixture was stirred at high speed for 10 minutes. After standing for 2 hours, a 1,2-dichloroethane solution was recovered, and a large amount of hexane was added thereto to recover a polymer. After recovery, a purification step was performed by washing with water, dissolving in chloroform, and adding methanol dropwise. Table 5 shows the molar fraction and the weight average molecular weight of the constituent units of the produced polymer. The mixing ratio between terephthalic acid chloride and isophthalic acid chloride was 1: 1 in molar ratio.

[0091]

[Table 4]

[0092]

[Table 5]

Next, the evaluation will be described. The apparatus used was a modified Hewlett Packard LBP "Laser Jet 4plus" (process speed: 71 mm / sec) equipped with a charging roller to which a voltage obtained by superimposing an AC voltage on a DC voltage was applied as a primary charging means. The remodeling is
The control of the primary charging was a constant voltage control. The prepared electrophotographic photoreceptor is used at 28 ° C. and 90% RH using this apparatus.
A paper passing durability test was performed under the following conditions. The sequence is
An intermittent mode in which the printing is stopped once for each print is set. When the toner ran out, replenished and continued until the image had a problem.

Further, abrasion was performed for 15 minutes using a Taber abrasion tester using a polishing tape, and the weight loss at that time was measured.

Further, a part of the electrophotographic photoreceptor
After illuminating with a white fluorescent lamp for 10 minutes in lux, the light-area potential was measured after standing for 10 minutes, and how much the light-area potential had dropped before the light was applied was determined as a photo memory value.

Further, the solvent cracking resistance was evaluated by observing the presence of solvent cracking by microscopic observation after leaving sebum adhered to the surface for 48 hours. The case where no solvent crack was observed was evaluated as ○, and the case where solvent crack was observed was evaluated as ×.

Table 6 shows the above results.

[0098]

[Table 6]

[0099]

Comparative Examples 1 to 4 Comparative Example 1 was a compound represented by the following formula (29) as a charge transport material for the charge transport layer.
And 4 were electrophotographic photoreceptors in the same manner as in Example 1 except that the hydrazone-based compound represented by the formula (5) was used, and the binder resins of the conditions 1 to 4 in Table 7 were used in Comparative Examples 1 to 4, respectively. Was created and evaluated. Table 8 shows the results.

[0100]

Embedded image

[0101]

[Table 7]

[0102]

[Table 8]

As is clear from the results in Tables 6 and 8, the electrophotographic photosensitive member obtained by combining the specific polyarylate resin and the specific hydrazone compound has a large H / H durability limit value (mechanical Excellent mechanical strength and electrical resistance to direct charging), a small Taber reduction value (excellent in mechanical strength), a small photo memory value (excellent in electrophotographic properties), and excellent solvent crack resistance.

[0104]

According to the present invention, excellent solvent crack resistance without impairing mechanical strength, high mechanical strength, good electric resistance against discharge by direct charging, and excellent electronic properties are obtained. It is possible to provide an electrophotographic photosensitive member having good photographic characteristics and suitable for direct charging, which is easy to manufacture, and a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member.

[Brief description of the drawings]

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electrophotographic photoreceptor of this invention 2 axis 3 Charging means 4 Image exposure light 5 Developing means 6 Transfer means 7 Transfer material 8 Image fixing means 9 Cleaning means 10 Pre-exposure light 11 Process cartridge 12 Rail

Claims (6)

[Claims] 1. An electrophotographic photosensitive member having a conductive support and a photosensitive layer, wherein the surface layer of the electrophotographic photosensitive member has a polymer having a structural unit represented by the following formula (1) and a polymer having the following formula (2): An electrophotographic photoreceptor comprising a charge transport material represented by the formula: Embedded image (Wherein X is —CR ³ R ⁴ — (wherein R ³ and R ⁴ are each independently a hydrogen atom, a trifluoromethyl group, an alkyl group, or an aryl group), or an optionally substituted cycloalkylidene group , Α, ω-alkylene group, single bond,-
O -, - S -, - SO-, or -SO ₂ - is. R ¹ and R ² are each independently a hydrogen atom, a halogen atom, an alkyl group or an aryl group which may be substituted, and a and b are each independently an integer of 0 to 4. ) (Wherein Y ¹ and Y ² each independently represent an alkyl group, alkenyl group, aralkyl group, aryl group,
Or a heterocyclic group. Y ³ and Y ⁴ are each independently a hydrogen atom, an alkyl group, an alkoxy group, or a halogen atom. ) 2. The electrophotographic photoreceptor according to claim 1, wherein the structural unit represented by the formula (1) is represented by the following formula (3). Embedded image 3. The electrophotographic photoreceptor according to claim 1, and at least one means selected from the group consisting of a charging means, a developing means and a cleaning means are integrally supported, and are detachably mountable to an electrophotographic apparatus main body. A process cartridge. 4. The process cartridge according to claim 3, wherein said charging means is a contact charging means. 5. An electrophotographic apparatus comprising the electrophotographic photoreceptor according to claim 1, a charging unit, an image exposing unit, a developing unit, and a transferring unit. 6. The electrophotographic apparatus according to claim 5, wherein said charging means is a contact charging means.