JP4250487B2 - Electrophotographic apparatus, process cartridge and facsimile apparatus - Google Patents

Description

  The present invention relates to an electrophotographic photosensitive member having a photosensitive layer containing a polymerizable functional group, an electrophotographic apparatus, a process cartridge, and a facsimile apparatus.

  2. Description of the Related Art Conventionally, in an electrophotographic apparatus employed in, for example, a copying machine, a printer, a facsimile, etc., an image bearing member (charged body) such as an electrophotographic photosensitive member or an electrostatic recording dielectric is uniformly set to a desired polarity and potential. A corona charger (corona discharger) is often used as a charging device that performs a charging process (including a charge removal process).

  In recent years, however, many contact charging devices have been proposed and put to practical use because of their advantages such as low ozone and low power compared to corona chargers.

  In the contact charging device, a charged member such as an image carrier is contacted with a conductive charging member (contact charging member / contact charger) such as a roller type, a fur brush type, a magnetic brush type, or a blade type. A system is used in which a predetermined charging bias is applied to the contact charging member to charge the surface of the object to be charged to a predetermined polarity and potential. In particular, a roller charging method using a conductive roller (charging roller) as a charging member is preferable and widely used in terms of charging stability. The charging roller is generally made of a conductive or medium resistance rubber material or foam. Furthermore, there are some obtained by laminating these to obtain desired characteristics.

  The charging roller as a contact charging member uses the above-mentioned foam as a constituent material to give a certain contact state with a member to be charged (hereinafter referred to as a photosensitive member) and has elasticity. The resistance is large, and in many cases, it is driven by a photoreceptor. Therefore, even if direct charging is attempted, a decrease in absolute charging capability, insufficient contact, roller-shaped unevenness, and charging unevenness due to adhering substances on the photosensitive member cannot be avoided. Dominant. That is, the roller charging charges the surface of the member to be charged by a discharge phenomenon that occurs in a minute gap with the member to be charged near the contact portion.

A conventional general electrophotographic apparatus using a charging roller will be described below.
6 is a front view showing a roller charging device and a photosensitive drum as an object to be charged, FIG. 7 is a sectional view taken along line AA in FIG. 6, and FIG. 8 is a charging roller of the roller charging device in FIG. FIG. 3 is a plan view of the photosensitive drum as viewed from above.

The photosensitive drum 101 is rotatably disposed and is driven to rotate in the direction indicated by the arrow K in FIG. The charging roller (roller contact charging member) 102 of the roller charging device is arranged in substantially parallel to abut on the surface of the photosensitive drum 101.

  The charging roller 102 includes, for example, a conductive metal core 102a such as iron or stainless steel, a conductive elastic body layer 102b provided by coating the outer periphery thereof in a roller shape, and a surface coating layer 102c further covering the outer periphery. . A conductive material such as carbon is dispersed in the conductive elastic layer 102b, and the conductive elastic layer 102b is adjusted to have a predetermined electric resistance by adjusting the amount and layer thickness of the conductive material. .

The charging roller 102 is accommodated in an opening of the housing 103, and the housing 103 is fixedly supported by a non-illustrated immovable member with a certain distance from the photosensitive drum 101. Inside the both ends of the housing 103, there are provided spring-bearing / bearing guides 104 in the vertical direction facing the photosensitive drum 101, and the conductive bearings 105 move up and down in the spring-bearing / bearing guides 104 at both ends. Installed as possible. The cored bar 102a of the charging roller 102 is rotatably supported by bearings 105 at both ends.

  As shown in FIG. 8, the bearing 105 is disposed so that the rotation shaft of the photosensitive drum 101 and the rotation shaft of the charging roller 102 are parallel to each other. The charging roller 102 includes the bearing 105 and the ceiling surface of the housing 103. Is pressed toward the rotation axis of the photosensitive drum 101 by the pressure of the conductive pressure spring 106 contracted between them (indicated by reference numerals G and H in FIG. 7), and is applied to the surface of the photosensitive drum 101. The contact state is maintained. Therefore, when the photosensitive drum 101 is rotated in the arrow K direction, the charging roller 102 is driven to rotate in the arrow J direction.

  An electrode plate 107 that is in contact with the pressure spring 106 is disposed on the ceiling surface portion of the housing 103 corresponding to one upper end of the pressure spring 106 at both ends. A charging power source 108 is connected to one end of the electrode plate 107 outside the housing 103, and a charging bias is applied to the charging roller 102 via a conductive pressure spring 106, a bearing 105 and a charging roller core metal 102a. As a result, the peripheral surface of the photosensitive drum 101 is charged to a desired potential and polarity.

  FIG. 9 is a graph showing an example of charging efficiency in contact charging. The horizontal axis represents the bias applied to the contact charging member, and the vertical axis represents the photosensitive member charging potential corresponding to the applied bias. As shown in FIG. 9, in the case of roller charging, charging starts after the discharge threshold of about −500V. Therefore, when charging to -500V, a DC voltage of -1000V is applied.

  More specifically, when the charging roller is brought into pressure contact with an organic photoreceptor having a thickness of 25 μm, if a voltage of about 640 V or more is applied, the surface potential of the photoreceptor starts to rise. Thereafter, the photoreceptor surface potential increases linearly with a slope of 1 with respect to the applied voltage. This threshold voltage is defined as the charging start voltage Vth. That is, in order to obtain the photoreceptor surface potential Vd required for electrophotography, the charging roller needs a direct current (DC) voltage of Vd + Vth or more. A method of charging by applying only the DC voltage to the contact charging member in this way is referred to as a “DC charging method”.

  However, in DC charging, the resistance value of the contact charging member fluctuates due to environmental fluctuations, etc., and the charging start voltage Vth fluctuates when the film thickness changes due to the photoconductor being scraped. It was difficult to make value. For this reason, as a technique for further uniformizing the charging, a voltage obtained by superimposing an alternating current (AC) component having a peak-to-peak voltage of 2 × Vth or more on a DC voltage corresponding to a desired Vd is applied to the contact charging member. An “AC charging method” is known (for example, Patent Document 1). This technique aims at the potential smoothing effect by AC. By using this technique, the potential of the member to be charged converges to Vd, which is the center of the peak of the AC voltage, and is not affected by disturbances such as the environment.

  More specifically, for example, in addition to the above-mentioned -500 V DC charging voltage, an AC voltage with a peak-to-peak voltage of 12.00 V is applied so as to always have a potential difference equal to or greater than the discharge threshold, thereby converging the photoreceptor potential to the charging potential. The method is common. Naturally, this method is also a charging method using a discharge phenomenon from the contact charging member to the photosensitive member. In this method, since there is an AC component in the voltage applied to the charging member, a voltage value equal to or higher than the discharge threshold is always applied between the photosensitive member surface potential, and the discharge is more positive than the method of charging only by DC charging. The charging method used in

Comparing the roller charging method with the corona charging method, the roller charging method uses the discharge phenomenon in the minute space, so the discharge current flows into the minute space between the photoreceptor surface and the charging roller surface. High-energy particles such as electrons and ions repeatedly collide with the surface of the photoreceptor. In addition, the total amount of discharge products is much smaller than that of a corona charger, but it is unavoidable in principle. Rather, the roller is charged only in a very narrow space near the nip formed between the photoreceptor surface and the charging roller, so the concentration of active ions such as ozone, which is a discharge product, is reduced. However, this is synonymous with a state in which the surface of the photoreceptor is exposed to a very high environment. In other words, the roller charging method is suitable as a charging method for bringing the photosensitive member to a desired charging potential with good controllability, but the oxidation reaction deterioration of the photosensitive member surface due to active ions such as ozone becomes more remarkable. The above-mentioned extremely high energy particles such as electrons and ions repeatedly collide with the surface of the photosensitive member, and as a result, the photosensitive member is likely to be scraped and easily damaged, resulting in a problem that the durability is significantly reduced. It was. Further, there have been problems such as deterioration of the cleaning property due to a decrease in the slipperiness of the surface of the photoreceptor.

  As described above, in the roller charging, the AC charging method positively uses the discharge rather than the DC charging method, and therefore the damage to the surface of the photoreceptor in the AC charging method is larger.

  In order to increase the durability of the photosensitive member against such problems, several techniques using a curable resin for the surface layer have been disclosed (for example, Patent Documents 2, 3, 4, 5, and 6). . With these technologies, it has become possible to reduce the problem of the photoconductor being scraped or scratched when the roller charging method is adopted (the problem of the durability of the photoconductor).

However, the AC current value flowing through the charging roller is large, and it is 40 mA / m (= total AC current value flowing from the high-voltage power source of the electrophotographic apparatus main body to the charging roller during image formation / the length of the charging roller).
According to the present inventors, the following problems arise as a result of conducting an endurance test on a photoreceptor having a surface layer made of a curable resin using an electrophotographic apparatus capable of high-speed printing as described above. It became clear.

  That is, the photoconductor scraping speed is very low, but during a durability test, suddenly deep scratches occur and grow, resulting in a difference in capacitance between the scratched portion and the non-scratched portion. In addition, toner accumulates in a scratched part that cannot be cleaned and the exposure is interrupted, resulting in a problem that an image defect due to the scratch appears and the endurance life is reached. That is, when a curable resin is used for the surface layer of the photoconductor, the life of the photoconductor is not a wear life but a scratch life. Generally, when a curable resin is used for the surface layer, it is strengthened with respect to scratches as well as shaving, so the durability life is longer than other thermoplastic resins by using a curable resin. It has become. However, the normal endurance life calculated by the amount of scraping, that is, the surface layer is shaved and thinned, the capacity as the photoreceptor increases, the chargeability deteriorates before the end of the life, and the suddenness is deep. In the case of scratches, in particular, when the surface layer is a thin protective layer, this occurs at an extremely early stage of durable use and has a problem of reaching the end of its life.

JP-A 63-149669 Japanese Patent Laid-Open No. 02-127652 JP 05-216249 A Japanese Patent Laid-Open No. 07-72640 Japanese Patent Laid-Open No. 11-265085 JP 2000-66425 A

  An object of the present invention is to suppress the occurrence of sudden scratches associated with the durable use of an electrophotographic photosensitive member, and to realize high durability of the electrophotographic photosensitive member.

The occurrence of sudden scratches due to the durable use of the electrophotographic photosensitive member is significant when the AC current value from the roller charging member to the conductive support of the electrophotographic photosensitive member is a large value of 40 mA / m or more. Become.

Therefore, the present invention provides an electrophotographic photosensitive member having a conductive support and a photosensitive layer formed on the conductive support, and a compound having a surface layer having at least one polymerizable functional group. An electrophotographic apparatus comprising: an electrophotographic photosensitive member, and a roller charging member that is disposed in contact with the electrophotographic photosensitive member and charges the electrophotographic photosensitive member when a voltage is applied thereto, wherein the roller charging member The AC current from the electrophotographic photosensitive member to the conductive support is 40 mA /
There is provided an electrophotographic apparatus that is equal to or greater than m and that has a rotation axis of the roller charging member and a rotation axis of the electrophotographic photosensitive member intersecting each other.

An electrophotographic photoreceptor comprising a conductive support and a photosensitive layer formed on the conductive support, wherein the surface layer has a compound having at least one polymerizable functional group. A photosensitive member, and a roller charging member that is placed in contact with the electrophotographic photosensitive member and charges the electrophotographic photosensitive member when a voltage is applied thereto, and is provided in a single and detachable manner on the main body of the electrophotographic apparatus. An AC current from the roller charging member to the conductive support of the electrophotographic photosensitive member is 40 mA / m or more, and the rotating shaft of the roller charging member and the electrophotographic photosensitive member Provided is a process cartridge in which a rotation axis intersects each other.

An electrophotographic photoreceptor comprising a conductive support and a photosensitive layer formed on the conductive support, wherein the surface layer has a compound having at least one polymerizable functional group. An electrophotographic apparatus comprising: a photosensitive member; and a roller charging member that is disposed in contact with the electrophotographic photosensitive member and charges the electrophotographic photosensitive member by applying a voltage. An electrophotographic apparatus in which an AC current to a conductive support of a photographic photosensitive member is 40 mA / m or more, and a rotating shaft of the roller charging member and a rotating shaft of the electrophotographic photosensitive member intersect each other; and a remote terminal And a means for receiving image information from the facsimile apparatus.

Further, the present invention provides an electrophotographic apparatus, a process cartridge, or a facsimile apparatus in which both ends of the roller charging member are pressed against the electrophotographic photosensitive member with a pressure of 5 kg / m or more.

  Further, as a result of intensive studies by the inventors, it has been found that a more remarkable effect can be obtained according to an electrophotographic apparatus having the following configuration.

Therefore, another invention is an electrophotographic photosensitive member having a conductive support and a photosensitive layer formed on the conductive support, and the surface layer thereof contains the above-mentioned compound and is elastic. Deformation rate 46% to 65%, HU (universal hardness value) 1.5 × 10 ⁸ N / m ^{2 to} 2.2 × 1
An electrophotographic photosensitive member of 0 ⁸ N / m ² or less, and a roller charging member that is disposed in contact with the electrophotographic photosensitive member and charges the electrophotographic photosensitive member with a discharge when a voltage is applied thereto. Provided is an electrophotographic apparatus, wherein an axis of rotation of the roller charging member and an axis of rotation of the electrophotographic photosensitive member intersect each other at an intersection angle of 0.4 degrees or more.

An electrophotographic photosensitive member having a conductive support and a photosensitive layer formed on the conductive support, the surface layer of which has an elastic deformation ratio of 46% to 65%, HU (universal). (Hardness value) 1.5 × 10 ⁸ N / m ² or more and 2.2 × 10 ⁸ N / m ² or less, an electrophotographic photosensitive member that is placed in contact with the electrophotographic photosensitive member, and a voltage is applied. And a roller charging member that charges the electrophotographic photosensitive member with discharge, and is a process cartridge that is integrally and detachably provided on the main body of the electrophotographic apparatus, the rotating cartridge of the roller charging member and the electronic Provided is a process cartridge in which a rotation axis of a photographic photoreceptor intersects each other at an intersection angle of 0.4 degrees or more.

An electrophotographic photosensitive member having a conductive support and a photosensitive layer formed on the conductive support, the surface layer of which contains the above-mentioned compound, and has an elastic deformation rate of 46%. An electrophotographic photosensitive member having a hardness of 65% or less and a HU (universal hardness value) of 1.5 × 10 ⁸ N / m ² or more and 2.2 × 10 ⁸ N / m ² or less; An electrophotographic apparatus having a roller charging member that is disposed in contact and charges the electrophotographic photosensitive member with discharge when a voltage is applied thereto, the rotating shaft of the roller charging member and the electrophotographic photosensitive member There is provided a facsimile apparatus comprising an electrophotographic apparatus in which rotation axes intersect each other at an intersection angle of 0.4 degrees or more and means for receiving image information from a remote terminal.

  Further, in each of the above configurations, the roller charging member is provided with an electrophotographic apparatus, a process cartridge, or a facsimile apparatus having a shape in which the outer peripheral diameter of the central portion is larger than the outer peripheral diameter of each end portion along the longitudinal direction. To do.

  According to the present invention, the surface of the photoconductor surface due to endurance use is reduced, and it is difficult to cause a sudden deep scratch.

(Embodiment 1)
Details of the present invention will be described below.

The electrophotographic apparatus of the present invention is an electrophotographic photosensitive member having a conductive support and a photosensitive layer formed on the conductive support, and the surface layer has at least one polymerizable functional group. An electrophotographic photosensitive member containing a compound obtained by curing a hole transporting compound, and a roller charging member that is placed in contact with the electrophotographic photosensitive member and charges the electrophotographic photosensitive member by applying a voltage. Have.

  The conductive support is not particularly limited as long as it has conductivity and can support the photosensitive layer.

  The photosensitive layer may be provided directly on the surface of the conductive support, or the conductive support through an appropriate other layer for improving the electrical characteristics and mechanical characteristics of the electrophotographic photosensitive member. It may be provided above.

  Further, the surface layer of the electrophotographic photosensitive member may be a part of the photosensitive layer, or may be another layer separated from the photosensitive layer.

The AC current from the roller charging member to the conductive support of the electrophotographic photosensitive member is 4 mA / m or more. The rotation axis of the roller charging member and the rotation axis of the electrophotographic photosensitive member intersect each other at the center of the roller charging member.

Further, the roller charging member is preferably in a state where the linear pressure at both ends of the roller is pressed against the electrophotographic photosensitive member with a pressing force of 5 kg / m or more. The polymerizable functional group is preferably an unsaturated polymerizable functional group represented by the following general formula (7).

｛式中、Ｅは水素原子、ハロゲン原子、置換基を有しても良いアルキル基、置換基を有しても良いアリール基、シアノ基、ニトロ基、アルコキシ基、−ＣＯＯＲ１（Ｒ１は水素原子、ハロゲン原子、置換基を有しても良いアルキル基、置換基を有しても良いアラルキル基および置換基を有しても良いアリール基）、ＣＯＮＲ２Ｒ８（Ｒ２、Ｒ８は水素原子、ハロゲン原子、置換基を有しても良いアルキル基、置換基を有しても良いアラルキル基および置換基を有しても良いアリール基を示し、互いに同一であっても異なっていてもよい）を示し、Ｗは置換基を有しても良い二価のアリーレン基または置換基を有しても良い二価のアルキレン基、−ＣＯＯ−、−Ｃ−、−Ｏ−、−ＯＯ−、−Ｓ−、−ＣＯＮＲ４−（Ｒ４は水素原子、ハロゲン原子、置換基を有しても良いアルキル基、置換基を有しても良いアラルキル基または置換基を有しても良いアリール基）を示す。ｆは０または１を示す。｝

{Wherein E is a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, a cyano group, a nitro group, an alkoxy group, -COOR1 (R1 is a hydrogen atom) , A halogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent and an aryl group which may have a substituent, CONR2R8 (R2 and R8 are a hydrogen atom, a halogen atom, An alkyl group that may have a substituent, an aralkyl group that may have a substituent, and an aryl group that may have a substituent, which may be the same or different from each other), W is a divalent arylene group which may have a substituent or a divalent alkylene group which may have a substituent, -COO-, -C-, -O-, -OO-, -S-, -CONR4- (R4 is a hydrogen atom or halogen atom) Indicates an alkyl group which may have a substituent, an aryl group) which may have a substituted or unsubstituted aralkyl group or a substituted group. f represents 0 or 1; }

  The compound having a polymerizable functional group represented by the general formula (7) is preferably a chain polymerizable compound having two or more polymerizable functional groups of the general formula (7) in one molecule.

  The polymerizable functional group is preferably any one of the general formulas (8) to (12).

  Moreover, it is particularly preferable that the polymerizable functional group is any one of the general formulas (8), (9) and (12).

  In the polymerizable functional group represented by the general formula (1), W is an arylene group obtained by removing two hydrogens from an aromatic hydrocarbon such as benzene or naphthalene, anthracene, pyrene, etc., which may have a substituent. Preferably there is.

The compound obtained by curing the hole transporting compound having a polymerizable functional group is preferably one that is polymerized and cured by heat or radiation.

Moreover, it is preferable that the compound which hardened the hole transportable compound which has the said polymeric functional group was hardened | cured with the electron beam.

  The acceleration voltage of the electron beam used for curing the compound is preferably 250 KV or less.

The irradiation dose of the electron beam is preferably 10 ⁴ to 10 ⁶ Gy.

  The electrophotographic photosensitive member is preferably formed by laminating a charge generation layer and a charge transport layer in this order.

  The photosensitive layer of the electrophotographic photosensitive member is preferably formed by laminating a charge generation layer, a charge transport layer, and a protective layer in this order.

The surface layer of the electrophotographic photosensitive member, tetrafluoroethylene resin, trifluorochloroethylene resin, hexafluoro ethylene propylene resin, vinyl fluoride resin, vinylidene fluoride resin, difluoride ethylene dichloride resin and It is preferable to contain one or more of fluorine atom-containing resin particles containing these copolymers.

  The surface layer of the electrophotographic photoreceptor preferably contains conductive particles.

  The conductive particles contained in the surface layer of the electrophotographic photoreceptor are preferably metal oxides.

  In the present invention, when an electrophotographic apparatus (image forming apparatus), a process cartridge, a facsimile apparatus, or the like capable of high-speed printing whose AC current value flowing through the charging roller is 4.0 mA / m or more is used, that is, the discharge current value is When image formation is performed in a large state of a certain value or more, it is intended to suppress deep scratches caused by durable use of the apparatus on the surface of the photoreceptor having the curable resin surface layer. The cause of the occurrence of such deep scratches in the conventional apparatus configuration is considered as follows.

The method of charging the surface of the photosensitive member with a charging roller uses a discharge phenomenon based on Paschen's law from the charging roller to the photosensitive member. Due to this discharge, active ions such as ozone and particles such as very high energy electrons and ions repeatedly collide with the surface of the photoconductor, thereby adsorbing discharge products on the surface of the photoconductor and oxidizing the surface of the photoconductor. Deterioration occurs. As a result, the surface of the photoconductor becomes very slippery and an increase in frictional force occurs between the surface of the photoconductor and a cleaning blade, which is a contact member with the photoconductor in the electrophotographic apparatus. In this state, under the more imaging engineering, on the photosensitive member, cleaning blur having rubber elasticity - movement of de, the stick on the photosensitive member, such as that leaves repeats the operation. Naturally, even during this movement, the developer is set between the photosensitive member and the cleaning blade so that there is no cleaning failure. As a result, there is a high probability that foreign matter is sandwiched between the photosensitive member and the cleaning blade. The foreign matter is, for example, paper dust or yarn waste mixed in the electrophotographic apparatus from the outside, and this is sandwiched between the cleaning blade and the photoconductor to damage the photoconductor surface, and the photoconductor surface is deeply scratched. I think it will be formed.

  In view of the above mechanism, the frictional force between the cleaning member and the surface of the photosensitive member is reduced by using an electrophotographic apparatus in which the rotating shaft of the roller charging member and the rotating shaft of the electrophotographic photosensitive member intersect each other. It becomes possible to make it.

An electrophotographic apparatus in which the rotating shaft of the roller charging member and the rotating shaft of the electrophotographic photosensitive member intersect each other is described in Japanese Patent Application Laid-Open Nos. 2001-117318 and 8-179787. In particular, in the present invention, the photoreceptor surface layer has at least one polymerizable functional group, and the AC current from the roller charging member to the conductive support of the electrophotographic photoreceptor is 4.0 mA / m. This is devised with respect to the flaw life of the photosensitive member, which becomes a problem in the above case. According to the present invention, the photoconductor can be prevented from being scraped or scratched, and the life of the photoconductor can be greatly extended. That is, a highly reliable electrophotographic apparatus can be provided.

  The mechanism that can reduce the increase in frictional force associated with the durable use of the surface of the photosensitive member by using an electrophotographic apparatus in which the rotating shaft of the roller charging member and the rotating shaft of the electrophotographic photosensitive member intersect each other is considered as follows. It is done.

When the rotating shafts of the photoconductor and the charging roller are twisted, a slight peripheral speed difference is generated between the photoconductor surface and the charging roller, and the photoconductor surface is rubbed. At this time, the charging roller itself rubs against the surface of the photosensitive member, and the charging roller rubs fine metal oxide particles added in the developer interposed between the surface of the photosensitive member and the charging roller. The effect is considered to remove the discharge product adsorbed on the surface of the photoreceptor and / or the discharge deterioration product on the outermost surface of the photoreceptor surface. As a result, the surface of the photoconductor can be refreshed while being discharged during image formation, and an increase in frictional force on the surface of the photoconductor due to discharge can be suppressed. As a result, the cleaning blade and the photoconductor It is considered that the probability of foreign object pinching in between decreases and deep scratches do not occur.

  However, on the other hand, as in the configuration of the present invention, the photosensitive material formed of a curable resin by rubbing due to frictional force (not so great) that causes twisting of the rubber material used for the charging roller. The reason why the deposits and deteriorated substances in the body surface discharge can be removed is considered as follows. The discharge product adsorbed on the surface of the photoconductor or the structure on the surface of the photoconductor deteriorated by the discharge can be removed by weak mechanical rubbing at the initial stage of generation on the surface of the photoconductor, but it takes time. It is expected that removal will be difficult. Therefore, it is considered that the rubbing simultaneously with the discharge works effectively for the removal of the discharge products on the surface of the photoreceptor as in the apparatus configuration of the present invention.

  The photoreceptor according to the present invention will be described below.

  The surface layer of the photoconductor of the present invention is an electrophotographic photoconductor containing a compound obtained by polymerizing or cross-linking at least one polymerizable functional group and curing, and the curing means is heat or visible light. In addition, light such as ultraviolet rays and radiation can be used. Therefore, the procedure for forming the surface layer in the present invention is a dip coating method, a spray coating method, a curtain coating method using a coating solution for dissolving or containing a compound that can be polymerized or crosslinked and cured for the surface layer. The coating is performed by a spin coating method or the like, and this is cured by the curing means. The dip coating method is the best for efficient mass production of the photoreceptor, and the dip coating method is also possible in the present invention.

The structure of the photoconductor of the present invention is a single layer type in which a layer containing both a charge generation material and a charge transport material (in the same layer) is formed on a conductive substrate, or charge generation containing a charge generation material. The layer and the charge transport layer containing the charge transport material are either of the stacked type in which the layers are stacked in this order or in the reverse order. Furthermore, a surface protective layer can be formed on the photosensitive layer. Incidentally, the photoreceptor 1 shown in FIG. 2 has a layer 1b containing both a charge generation material and a charge transport material formed on a conductive substrate 1a, and further a surface protective layer 1c formed thereon (the latter). is there. In the present invention, at least the surface layer of the photoreceptor only needs to contain a compound that can be polymerized or crosslinked and cured by heat, light such as visible light or ultraviolet light, and radiation. However, from the viewpoint of characteristics as a photoreceptor, particularly electrical characteristics such as residual potential and durability, a function-separated photoreceptor structure in which a charge generation layer / charge transport layer are laminated in this order, or laminated in this configuration. A structure in which a surface protective layer is formed on the photosensitive layer formed is preferable.

In the present invention, it is preferable to use radiation in the method of curing the compound for crosslinking or crosslinking the surface layer, since the residual potential does not increase without deterioration of the photoreceptor characteristics, and sufficient hardness can be exhibited. .

At this time, the radiation used is an electron beam and a γ-ray. In the case of electron beam irradiation, any type of accelerator such as a scanning type, an electro curtain type, a broad beam type, a pulse type, and a laminar type can be used. In the case of irradiating an electron beam, the acceleration voltage is preferably 250 kV or less, and optimally 150 kV or less, in order to develop the electrical characteristics and durability of the photoreceptor of the present invention. The irradiation dose is preferably in the range of 10 ⁴ Gy to 10 ⁶ Gy, more preferably in the range of 3 × 10 ⁴ Gy to 5 × 10 ⁵ Gy. If the accelerating voltage exceeds the above, the electron beam irradiation damage tends to increase on the characteristics of the photoreceptor. In addition, when the irradiation dose is less than the above range, the curing tends to be insufficient, and when the dose is high, the photoreceptor characteristics are likely to be deteriorated.

  Surface layer compounds that can be polymerized or crosslinked and cured include unsaturated polymerizable functional groups in the molecule from the standpoints of high reactivity, high reaction rate, and high hardness achieved after curing. Those having a group are preferred, and among them, compounds having an acrylic group, a methacryl group, and a styrene group are particularly preferred.

In the present invention, the compound having an unsaturated polymerizable functional group is roughly classified into a monomer and an oligomer by repeating the structural unit. Monomer means a compound having a relatively small molecular weight without repeating a structural unit having an unsaturated polymerizable functional group, and an oligomer has 2 to 2 structural units having an unsaturated polymerizable functional group. It is a polymer of about 0.0. Further, polymer - or oligomer - macromonomer having an unsaturated polymerizable functional groups only at the terminal - can be used as curable compound for the surface layer of the present invention.

  In addition, the compound having an unsaturated polymerizable functional group in the present invention is preferably a charge transport compound in order to satisfy the charge transport function necessary for the surface layer. Among these, an unsaturated polymerizable compound having a hole transport function is more preferable.

Examples thereof are No. 1 to No. 1 in Tables 1 and 2. 44, no. 48, no. 49,
The compounds that can be used in the present invention are not limited to these.

  Next, the photosensitive layer of the electrophotographic photoreceptor according to the present invention will be described.

The support for the electrophotographic photosensitive member may have any conductivity, for example, aluminum, copper, chromium, nickel, zinc, stainless steel, or other metal or alloy formed into a drum or sheet, aluminum, copper, etc. Metal foil laminated with plastic film, aluminum, indium oxide and tin oxide deposited on plastic film, metal with conductive layer applied alone or with binder resin, or plastic film And paper. In the present invention, an undercoat layer having a barrier function and an adhesive function can be provided on the conductive support. The undercoat layer is used to improve the adhesion of the photosensitive layer, improve the coatability, protect the support, cover defects on the support, improve the charge injection from the support, and protect against electrical breakdown of the photosensitive layer. Formed. As the material for the undercoat layer, polyvinyl alcohol, poly-N-vinylimidazole, polyethylene oxide, ethyl cellulose, ethylene-acrylic acid copolymer, casein, polyamide, N-methoxymethylated 6 nylon, copolymer nylon and gelatin are used. Is possible. These are dissolved in a solvent suitable for each and coated on a support. The film thickness at that time is preferably 0.1 to 2 μm.

  When the photoreceptor of the present invention is a function separation type photoreceptor, a charge generation layer and a charge transport layer are laminated. Examples of the charge generation material used in the charge generation layer include selenium-tellurium, pyrylium, thiapyrylium dyes, various central metals and crystal systems, specifically, crystal types such as α, β, γ, ε, and X types. Phthalocyanine-based compounds, anthanthrone pigments, dibenzpyrenequinone pigments, pyranthrone pigments, trisazo pigments, disazo pigments, monoazo pigments, indigo pigments, quinacridone pigments, asymmetric quinocyanine pigments, quinocyanines, and JP-A No. 54-143645 Examples thereof include amorphous silicone.

  In the case of a functionally separated type photoreceptor, the charge generation layer is formed of the charge generation material, such as a homogenizer, an ultrasonic dispersion, a ball mill, a vibration ball mill, a sand mill, an attritor, a roll mill, etc. It is well dispersed by the method, and is formed by applying a dispersion and drying, or formed as a single composition film such as a vapor deposition film of the charge generation material. The film thickness is preferably 5 μm or less, and particularly preferably in the range of 0.1 to 2 μm.

  What can be used as the binder resin is a polymer or copolymer of vinyl compounds such as styrene, vinyl acetate, vinyl chloride, acrylic acid ester, methacrylic acid ester, vinylidene fluoride, trifluoroethylene, polyvinyl alcohol, Examples include polyvinyl acetal, polycarbonate, polyester, polysulfone, polyphenylene oxide, polyurethane, cellulose resin, phenol resin, melamine resin, silicon resin, and epoxy resin.

  In the present invention, the hole transporting compound having an unsaturated polymerizable functional group has a charge transport layer formed on the charge generation layer or a charge transport layer composed of a charge transport material and a binder resin on the charge generation layer. After forming, it can also be used as a surface protective layer.

When used as a surface protective layer, the charge transport layer corresponding to the lower layer is a suitable charge transport material such as a polymer compound having a heterocyclic ring or condensed polycyclic aromatic compound such as poly-N-vinylcarbazole or polystyrylanthracene, or pyrazoline. , Heterocyclic compounds such as imidazole, oxazole, triazole, carbazole, triarylalkane derivatives such as triphenylmethane, triarylamine derivatives such as triphenylamine, phenylenediamine derivatives, N-phenylcarbazole derivatives, stilbene derivatives, hydrazone derivatives, etc. low molecular compounds such as a suitable binder resin applied by a known method of solution dispersed / dissolved with a solvent before predicate (can be selected from the above-mentioned charge-generating layer resin), it is formed by dry it can. In this case, the ratio of the charge transport material to the binder resin is preferably selected in the range of 30 to 100, preferably 50 to 100, when the total weight of both is 100. When the amount of the charge transport material is less than that, the charge transport ability is lowered, and problems such as a decrease in sensitivity and an increase in residual potential occur. Also in this case, the film thickness of the photosensitive layer is in the range of 5 to 30 μm, and the film thickness of the photosensitive layer at this time is the total thickness of the charge generation layer, the charge transport layer, and the surface protective layer. is there.

In any case, the surface layer is formed by applying the solution containing the hole transporting compound,
The polymerization / curing reaction is generally carried out, but the surface containing the hole transporting compound previously reacted with the solution containing the hole transporting compound to obtain a cured product and then again dispersed or dissolved in the solvent is used. It is also possible to form layers. As a method for applying these solutions, for example, a dip coating method, a spray coating method, a curtain coating method, a spin coating method and the like are known, but the dip coating method is preferable from the viewpoint of efficiency / productivity. Also, vapor deposition, plasma and other known film forming methods can be appropriately selected.

  Conductive particles may be mixed in the surface protective layer in the present invention. Examples of the conductive particles include metals, metal oxides, and carbon black. Examples of the metal include aluminum, zinc, copper, chromium, nickel, stainless steel, and silver, or those obtained by depositing these metals on the surface of plastic particles. Examples of the metal oxide include zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, bismuth oxide, tin-doped indium oxide, antimony-doped tin oxide, and antimony-doped zirconium oxide. These can be used alone or in combination of two or more. When two or more types are used in combination, they may be simply mixed, or may be in the form of a solid solution or fusion. The average particle size of the conductive particles used in the present invention is preferably 0.3 μm or less, and particularly preferably 0.1 μm or less, from the viewpoint of the transparency of the protective layer. In the present invention, among the conductive particles as described above, it is particularly preferable to use a metal oxide in terms of transparency.

The ratio of the conductive metal oxide particles in the surface protective layer is one of the factors that directly determine the resistance of the surface protective layer, and the resistance of the protective layer is in the range of 10 ¹⁰ to 10 ¹⁵ ohm · cm. It is preferable.

  The surface layer in the present invention can contain fluorine atom-containing resin particles. Fluorine atom-containing resin particles include tetrafluoroethylene resin, trifluoroethylene chloride resin, hexafluoroethylene propylene resin, vinyl fluoride resin, vinylidene fluoride resin, ethylene difluoride dichloride resin, and their co-polymers. One or two or more types are preferably selected from the combination, but tetrafluoroethylene resin and vinylidene fluoride resin are particularly preferable. The molecular weight of the resin particles and the particle size of the particles can be appropriately selected and are not particularly limited. The proportion of fluorine atom-containing resin particles in the surface layer is preferably 5 to 70% by weight, more preferably 10 to 60% by weight, based on the total weight of the surface layer. If the proportion of fluorine atom-containing resin particles is more than 70% by weight, the mechanical strength of the surface layer tends to decrease, and if the proportion of fluorine atom-containing resin particles is less than 5% by weight, the surface layer surface releasability, surface layer In some cases, the wear resistance and scratch resistance are not sufficient.

  In the present invention, additives such as radical scavengers and antioxidants may be added to the surface layer for the purpose of further improving dispersibility, binding properties and weather resistance.

The film thickness of the surface protective layer used in the present invention is preferably in the range of 0.2 to 10 μm, more preferably in the range of 0.5 to 6 μm.

An electrophotographic apparatus that forms an image using the photoconductor prepared as described above will be described below.

  FIG. 1 is a front view showing a roller charging device and a photosensitive drum of an object to be charged according to the present invention, FIG. 2 is a cross-sectional view taken along line AA of FIG. 1, and FIG. It is the top view which looked at the photosensitive drum from the upper part.

As shown in FIG. 2, the charging roller 2 of the roller charging device 10 includes, for example, a conductive metal core 2a such as iron or stainless steel, and a conductive elastic body layer 2b provided with a roller-like outer periphery. Furthermore, it is comprised from the surface coating layer 2c which coat | covered the outer periphery. A conductive material such as carbon is dispersed in the conductive elastic layer 2b, and the conductive elastic layer 2b is adjusted to have a predetermined electric resistance by adjusting the amount and thickness of the conductive material. .

  As shown in FIG. 1, the charging roller 2 is accommodated in an opening of a housing 3, and the housing 3 is fixedly supported by a non-illustrated immovable member with a certain distance from the photosensitive drum 1. Inside the both ends of the housing 3, there are provided spring bearing / bearing guides 4 in the vertical direction facing the photosensitive drum 1, and the bearings 5 are mounted in the spring bearings / bearing guides 4 at both ends so as to be movable up and down. It has been. A cored bar 2 a of the charging roller 2 is rotatably supported by a bearing 5.

  The charging roller 2 is formed on the surface of the photosensitive drum 1 by applying pressure of a conductive pressure spring 6 that is contracted between the bearings 5 and the ceiling surface of the housing 3 (indicated by reference numerals G and H in FIG. 1). It is pressed toward the rotating shaft and kept in contact with the surface of the photosensitive drum 1. Therefore, when the photosensitive drum 1 is rotated in the arrow K direction in FIG. 2, the charging roller 2 is driven to rotate in the arrow J direction.

  An electrode plate 7 that is in contact with the pressure spring 6 is disposed on the ceiling surface portion of the housing 3 corresponding to one upper end of the pressure spring 6 at both ends, and the charging power source 8 is connected to the electrode plate 7. Is done. A charging bias voltage obtained by superimposing an AC voltage and a DC voltage from the charging power source 8 is applied to the charging roller 2 via the conductive pressure spring 6, the bearing 5, and the charging roller core 2a. The peripheral surface is charged to a desired potential and polarity.

  In the apparatus configuration of the present invention, the spring bearing / bearing guide 4 and the bearing 5 are installed at an angle (crossing angle) θ with respect to the rotational axis of the photosensitive drum 1, as shown in FIG. 2 is brought into contact with the rotational axis of the photosensitive drum 1 so as to intersect with the central portion at an angle θ. The pressing is preferably performed at a linear pressure of 5 kg / m or more. Further, the crossing angle θ is preferably 0.4 ° or more. Below 0.4 °, the sliding of the charging roller 2 is weak and the effect of providing an intersection angle is small. On the other hand, the upper limit of the crossing angle θ is determined by the nip formation state (determined by the diameter, elastic modulus, and pressure) between the curvature of the photoreceptor and the charging roller. If θ is too large, the nip width between the photosensitive member and the charging roller changes greatly in the longitudinal direction on the photosensitive member, the discharge state is disturbed, and the charging potential of the photosensitive member becomes non-uniform, resulting in image defects. Arise. In the present invention, θ can be increased up to the upper limit where the charging potential becomes non-uniform, and the larger the surface rubbing force of the photoreceptor can be obtained.

  As described above, when the charging roller 2 is brought into contact with the central axis of the charging roller 2 so as to intersect the rotational axis of the photosensitive drum 1, pressure is applied to both ends of the core metal 2a of the charging roller 2 toward the rotational axis of the photosensitive drum 1. Since the peripheral surfaces of the charging roller 2 and the photosensitive drum 1 are curved surfaces, as shown in FIG. 3, the charging roller 2 has both ends and the vicinity of the intersection F between the central portion of the charging roller 2 and the photosensitive drum 1. As shown in FIG. 2, the charging roller contacts the photosensitive drum in such a way that the amount of penetration δ in the normal direction of the charging roller 2 with respect to the outer peripheral surface of the photosensitive drum 1 becomes the largest.

  The present invention can be applied not only to electrophotographic apparatuses such as copying machines, laser printers, LED printers, and liquid crystal shutter printers, but also to images from displays, recording, light printing, plate making, or remote terminals using electrophotographic technology. The present invention can be widely applied to apparatuses such as facsimiles having a function of receiving information.

  Hereinafter, the present invention will be described in more detail with reference to examples.

Example 1
[Example 1-1]
(Photoconductor manufacturing method)
Hereinafter, “part” in Example 1 means “part by mass”.

  The photosensitive drum of the present invention was prepared as follows.

  First, the coating material for conductive layers was prepared by the following procedure. 50 parts of conductive titanium oxide powder coated with tin oxide containing 10% antimony oxide, 25 parts of phenol resin, 2.0 parts of methyl cellosolve, 5 parts of methanol and silicone oil (polydimethylsiloxane polyoxyalkylene copolymer) , 0.002 part of an average molecular weight of 3000) was prepared by dispersing for 2 hours in a sand mill apparatus using φ1 mm glass beads. This paint was applied onto an aluminum cylinder having a diameter of 30 mm × 357.5 mm by a dip coating method and dried at 140 ° C. for 30 minutes to form a conductive layer having a film thickness of 16 μm.

  Next, 5 parts of N-methoxymethylated nylon was dissolved in 95 parts of methanol to prepare an intermediate layer coating solution. This coating solution was applied onto the conductive layer by a dip coating method and dried at 100 ° C. for 2.0 minutes to form an intermediate layer having a thickness of 0.6 μm.

  Next, 3 parts of oxytitanium phthalocyanine having strong peaks at 9.0 °, 14.2 °, 23.9 ° and 27.1 ° of the Bragg angle (2θ ± 0.2 °) in CuKα characteristic X-ray diffraction , 2 parts of polyvinyl butyral (trade name: Esletk BM2, manufactured by Sekisui Chemical Co., Ltd.) and 35 parts of cyclohexanone are dispersed for 2 hours in a sand mill using φ1 mm glass beads, and then 60 parts of ethyl acetate is added to generate charge. A layer coating solution was prepared. This coating solution was applied onto the intermediate layer by a dip coating method and dried at 100 ° C. for 1.5 minutes to form a charge generation layer having a thickness of 0.2 μm.

Next, Compound Example Nos. 11 parts was dissolved in a mixed solvent of 1.5 parts of dichloromethane and 40 parts of toluene to prepare a coating material for charge transport. This paint is applied on the charge generation layer by dip coating, dried at 50 ° C. for 1.5 minutes, and then irradiated with an electron beam under conditions of an acceleration voltage of 1.50 kV and an irradiation dose of 3 × 10 ⁵ Gy. By curing the resin, a charge transport layer having a thickness of 18 μm was formed, and an electrophotographic photosensitive member was produced.

<Configuration of electrophotographic apparatus>
FIG. 4 is a cross-sectional view showing the configuration of an electrophotographic printer which is an electrophotographic apparatus according to an embodiment of the present invention. 4 shows a photosensitive drum 1 that is an image carrier for transferring a toner image onto a transfer material, a charging roller 2 that is a charging member that uniformly charges the photosensitive drum 1, and a process speed of the photosensitive drum 1. And a control means (control device) 13 for controlling the level of the voltage applied to the charging roller 2.

  4 also contains a laser scanner 23 for forming an electrostatic latent image on the photosensitive drum 1, a developing device 24 for developing the formed electrostatic latent image, and a transfer material for transferring the developed toner image. A cassette 25 that feeds the transfer material from the cassette 25, and a timing roller 27 that transfers the transfer material fed by the paper feed roller 26 to the photosensitive drum 1 in a timely manner.

  Further, FIG. 4 shows a transfer roller 28 that presses the transfer material against the photosensitive drum 1 to transfer the toner image onto the transfer material, a fixing device 29 that fixes the transfer material onto which the toner image has been transferred, and the toner image. A discharge roller 30 that discharges the fixed transfer material to the outside of the electrophotographic apparatus, a discharge tray 31 that receives the transferred transfer material, and a cleaner 12 that cleans the remaining transfer toner are provided.

  The cleaning blade constituting the cleaner 12 is made of polyurethane rubber that is integrally held at the front end of the sheet metal, and is in contact with the photosensitive drum 1 under conditions of a predetermined penetration amount and a set angle.

  As will be described later, the electrophotographic apparatus of FIG. 4 has a structure in which a process cartridge that supports the photosensitive drum 1, the charging roller 2, and the cleaner 12 can be attached and detached.

  The laser scanner 23 performs raster scanning based on the image signal for exposure. The laser scanner 23 scans the flashing of the semiconductor laser with a polygon scanner and irradiates the photosensitive drum 1 with an optical system.

  The developing device 24 performs jumping development, two-component development, FEED development, and the like, and is used in combination with reversal development in which a laser is turned on to attach toner to the lower potential of the latent image. .

  Further, the transfer roller 28 is an elastic body having low conductivity, and is electrostatically transferred by a bias electric field at a nip formed by the photosensitive drum 1 and the transfer roller 28.

  The process cartridge that can be attached to and detached from the electrophotographic apparatus main body supports the photosensitive drum 1, the charging roller 2, and the cleaner 12 by a process cartridge frame. The cleaner 12 includes a blade that scrapes off the transfer residual toner from the photosensitive drum 1 and a screw that transports the scraped toner to a waste toner container (not shown).

<Operation of electrophotographic apparatus>
Next, the operation of the electrophotographic apparatus shown in FIG. 4 will be described. First, a voltage controlled to the photosensitive drum 1 by the control means 13 is applied to the charging roller 2. Then, uniform charging is performed on the photosensitive drum 1 by the charging roller 2.

  Next, the laser scanner 23 performs raster scanning based on the image signal and performs exposure. The laser scanner 23 scans the flashing of the semiconductor laser with a polygon scanner and irradiates the photosensitive drum with an optical system. Thus, an electrostatic latent image is formed on the photosensitive drum 1.

  Then, the electrostatic latent image is developed by the developing device 24. For the development, jumping development or the like is used, and recording is performed in combination with reversal development in which a laser is turned on to attach toner to the lower potential of the latent image. In this state, when a print signal is sent from the host computer, the transfer material stored in the cassette 25 is fed one by one by the paper feed roller 26.

  At this time, the photosensitive drum 1 is controlled to operate at a process speed (PS) of 210 mm / sec. Then, the transfer material is transferred to the photosensitive drum side by the timing roller 27. Thus, the toner image is transferred onto the transfer material by the transfer roller 28 in synchronization with the image signal. The transfer material onto which the toner image has been transferred is fixed by the fixing device 29, sent to the outside of the apparatus by the paper discharge roller 30, and discharged to the paper discharge tray 31.

  On the other hand, the toner remaining after transfer is removed by the cleaning blade of the cleaner 12 and is transported by the screw without being scattered outside the cleaning device by the waste toner collecting sheet, and stored in the waste toner collecting container.

<Configuration of charging roller>
The charging roller 2 has a conductive EPDM rubber formed on a stainless steel core and a surface layer formed on the surface.

In this embodiment, the width of the charging roller 2 in pressure contact with the photosensitive drum 1 is 32 cm, and the AC current to the photosensitive drum 1 is about 5.8 mA / m (= the main body of the electrophotographic apparatus during image formation). AC current value flowing from the high voltage power supply to the charging roller: 1850 μA / charging roller length: 32c
m).

  Further, the pressure contact pressure of the roller charging device 2 to the photosensitive drum 1 is 700 gf as the pressure springs at both ends. Further, the weight of the charging roller 2 was about 150 g. At this time, a pressure sensor was installed so as to replace the outer peripheral surface of the photosensitive drum 1 and the total pressure applied by the charging roller 2 to the photosensitive drum 1 was measured. The value was about 1550 g, which was converted into linear pressure. And was about 4.84 kg / m.

  The linear pressure described here is the total pressure (unit: g) of the contact pressure of the charging roller 2 with respect to the photosensitive drum 1, as shown in FIG. cm). Even if the charging roller 2 is pressed using a pressure spring similar to the pressure spring 6, the total pressure of the contact pressure of the charging roller 2 with respect to the photosensitive drum 1 depends on the pressure of the charging roller 2 depending on the pressing direction. Since the influence is different, it is necessary to perform measurement in a state in which a pressure spring or the like is actually incorporated in the charging device 10 or in a state in which the charging device 10 is incorporated in an electrophotographic apparatus or the like.

  The electrophotographic apparatus was installed in a normal temperature and humidity environment (20 ° C., 50% RH), and an endurance test was conducted to examine the scratches generated on the surface of the photosensitive layer. The results are shown in Table 3.

  As shown in Table 3, image defects due to scratches on the surface of the photosensitive member where the charging roller is in contact do not occur even when 150K sheets are used for endurance. High durability of the photoreceptor was achieved.

Further, when the depth of the deepest scratch was measured on the surface of the photoconductor at the time when 150 K sheets were used, it was 1.8 μm in the average of eight points measured in the circumferential direction of the photoconductor.

[Example 1-2]
The charge transport layer of the photoconductor of Example 1-1 was changed as follows . 10 parts of the charge transport material is a scan styryl compound and polycarbonate (weight average molecular weight = 46000) and 10 parts of the solution prepared was dissolved in a mixed solvent of 30 parts / monochlorobenzene 60 parts of dichloromethane, the charge generating layer and the solution The surface was dip coated and dried at 120 ° C. for 60 minutes to form a charge transport layer having a thickness of 10 μm.

Next, Compound Example Nos. 11 parts of the compound shown in 11 is 50 parts of butyl alcohol /
It was dissolved in a mixed solvent of 50 parts of ethyl alcohol to prepare a coating material for the surface protective layer. This paint is applied onto the charge transport layer by dip coating, dried at 50 ° C. for 1.5 minutes, and then irradiated with an electron beam under conditions of an acceleration voltage of 150 kV and an irradiation dose of 3 × 10 ⁵ Gy. Was cured to form a surface protective layer having a thickness of 5 μm, and an electrophotographic photosensitive member was produced.

  This photoreceptor was evaluated in the same manner as in Example 1-1 using the electrophotographic apparatus shown in Example 1-1. The results are shown in Table 3. As shown in Table 3, image defects due to scratches on the surface of the photosensitive member where the charging roller is in contact do not occur even when 150K sheets are used for endurance. High durability of the photoreceptor was achieved.

  Further, when the depth of the deepest scratch was measured on the surface of the photosensitive member at the time when 150 K sheets were used, the average of eight points measured in the circumferential direction of the photosensitive member was 1.7 μm.

[Example 1-3]
A photoconductor was prepared by the same configuration and method as in Example 1-2 except that the surface protective layer in Example 1-2 was changed as follows.

No. in Table 2 10 parts of a compound containing 46 acryloyloxy groups were dissolved in a mixed solvent of 60 parts of dichloromethane / 12.0 parts of toluene together with 10 parts of a styryl compound contained in the charge transport layer shown in Example 1-2 to protect the surface. A layer coating was prepared. The paint is applied onto the charge transport layer by spray coating, dried at 120 ° C. for 60 minutes, and then cured with an electron beam under conditions of an acceleration voltage of 150 kV and an irradiation dose of 3 × 10 ⁵ Gy. Thus, a surface protective layer having a thickness of 5 μm was formed to prepare a photoconductor.

  This photoreceptor was evaluated in the same manner as in Example 1-1 using the electrophotographic apparatus shown in Example 1-1. The results are shown in Table 3. As shown in Table 3, image defects due to scratches on the surface of the photosensitive member where the charging roller is in contact do not occur even when 150K sheets are used for endurance. High durability of the photoreceptor was achieved.

  Further, when the depth of the deepest scratch was measured on the surface of the photosensitive member at the time when 150 K sheets were used for durability, the average of eight points in the circumferential direction of the photosensitive member was 2.6 μm.

[Example 1-4]
The compounds of Table 1 or Table 2 used in the surface protective layer of Example 1-2 were prepared as Example No. A surface protective layer and a photosensitive layer were prepared by the same configuration and method as in Example 1-2 except that the composition was changed to 43 (Table 2) to prepare a photoreceptor. This photoreceptor was evaluated in the same manner as in Example 1-1 using the electrophotographic apparatus shown in Example 1-1. The results are shown in Table 3. As shown in Table 3, image defects due to scratches on the surface of the photosensitive member where the charging roller is in contact do not occur even when 150K sheets are used for endurance. High durability of the photoreceptor was achieved.

  Further, when the depth of the deepest scratch was measured on the surface of the photosensitive member at the time when 150 K sheets were used, the average of eight measurement points in the circumferential direction of the photosensitive member was 2.0 μm.

[Example 1-5]
5 parts of polytetrafluoroethylene fine particles (particle size: 0.18 μm) were added to the coating material for the surface protective layer of Example 1-2, and compound example No. 1 in Table 1 was added. 20 parts of the compound shown in 20 was dissolved in a mixed solvent of 50 parts of butyl alcohol / 50 parts of ethyl alcohol to prepare a coating material for the surface protective layer. This paint is applied on the charge transport layer by dip coating, dried at 50 ° C. for 15 minutes, and then irradiated with an electron beam under conditions of an acceleration voltage of 150 kV and an irradiation dose of 3 × 10 ⁵ Gy to cure the resin. Thus, a surface protective layer having a film thickness of 5 μm was formed to produce an electrophotographic photosensitive member.

  This photoreceptor was evaluated in the same manner as in Example 1-1 using the electrophotographic apparatus shown in Example 1-1. The results are shown in Table 3. As shown in Table 3, image defects due to scratches on the surface of the photosensitive member where the charging roller is in contact do not occur even when 150K sheets are used for endurance. High durability of the photoreceptor was achieved.

  Further, when the depth of the deepest scratch was measured on the surface of the photosensitive member at the time of durable use of 150K sheets, the average of eight measurement points in the circumferential direction of the photosensitive member was 1.3 μm.

[Example 1-6]
When the charge transport layer of Example 1-1 was cured, the photosensitive layer was formed by the same configuration and method as in Example 1-1 except that the electron transport was not used and the resin was dried and cured at 140 ° C. for 60 minutes. A photoreceptor was prepared.

  This photoreceptor was evaluated in the same manner as in Example 1-1 using the electrophotographic apparatus shown in Example 1-1. The results are shown in Table 3. As shown in Table 3, image defects due to scratches on the surface of the photosensitive member where the charging roller is in contact do not occur even when 150K sheets are used for endurance. High durability of the photoreceptor was achieved.

  Further, when the depth of the deepest scratch was measured on the surface of the photosensitive member at the time when 150 K sheets were used, it was 3.1 μm on an average of eight points in the circumferential direction of the photosensitive member.

[Example 1-7]
The compounds of Table 1 or Table 2 used for the surface protective layer of Example 1-2 were prepared as Example No. A surface protective layer and a photosensitive layer were prepared by the same configuration and method as in Example 1-2 except that the composition was changed to 49 (Table 2) to prepare a photoreceptor. This photoreceptor was evaluated in the same manner as in Example 1-1 using the electrophotographic apparatus shown in Example 1-1. The results are shown in Table 3. As shown in Table 3, image defects due to scratches on the surface of the photosensitive member where the charging roller is in contact do not occur even when 150K sheets are used for endurance. High durability of the photoreceptor was achieved.

  Further, when the depth of the deepest scratch was measured on the surface of the photosensitive member at the time when 150 K sheets were used, it was 3.0 μm in an average of eight points in the circumferential direction of the photosensitive member.

[Example 1-8]
The same evaluation as in Example 1-2 was performed using the electrophotographic apparatus shown in Example 1-2, except that the AC current to the photosensitive drum 1 of the electrophotographic apparatus in Example 1-2 was 40 mA / m. Went. The results are shown in Table 3. As shown in Table 3, the image defect due to the scratch on the surface of the photosensitive member where the charging roller is in contact does not occur even if the durability of 150K sheets is performed. In the above-described electrophotographic apparatus using the AC current value, High durability of the photoconductor was achieved.

  Further, when the depth of the deepest scratch was measured on the surface of the photosensitive member at the time when 150 K sheets were used for durability, the average of eight measurement points in the circumferential direction of the photosensitive member was 1.4 μm.

[Example 1-9]
The electrophotographic apparatus shown in Example 1-2 was used except that the charging roller pressed against the photosensitive drum 1 of the electrophotographic apparatus of Example 1-2 was 4.2 kg / m. The same evaluation was performed. The results are shown in Table 3. As shown in Table 3, the image defect due to the scratch on the surface of the photosensitive member where the charging roller is in contact does not occur even if the durability of 150K sheets is performed. In the above-described electrophotographic apparatus using the AC current value, High durability of the photoconductor was achieved.

  Further, when the depth of the deepest scratch was measured on the surface of the photosensitive member at the time when 150 K sheets were used, the average of eight measurement points in the circumferential direction of the photosensitive member was 2.0 μm.

[Example 1-10]
The electrophotographic apparatus shown in Example 1-2 was used except that the charging roller pressed against the photosensitive drum 1 of the electrophotographic apparatus of Example 1-2 was 5.5 kg / m. The same evaluation was performed. The results are shown in Table 3. As shown in Table 3, the image defect due to the scratch on the surface of the photosensitive member where the charging roller is in contact does not occur even if the durability of 150K sheets is performed. In the above-described electrophotographic apparatus using the AC current value, High durability of the photoconductor was achieved.

  Further, when the depth of the deepest scratch was measured on the surface of the photosensitive member at the time when 150 K sheets were used, the average of eight measurement points in the circumferential direction of the photosensitive member was 1.5 μm.

[Example 1-11]
The electrophotographic apparatus shown in Example 1-2 was used except that the charging roller pressed against the photosensitive drum 1 of the electrophotographic apparatus of Example 1-2 was 6.0 kg / m. The same evaluation was performed. The results are shown in Table 3. As shown in Table 3, the image defect due to the scratch on the surface of the photosensitive member where the charging roller is in contact does not occur even if the durability of 150K sheets is performed. In the above-described electrophotographic apparatus using the AC current value, High durability of the photoconductor was achieved.

  Further, when the depth of the deepest scratch was measured on the surface of the photosensitive member at the time when 150 K sheets were used for durability, the average of eight measurement points in the circumferential direction of the photosensitive member was 1.4 μm.

Example 1-12 The electrophotographic apparatus shown in Example 1-2 was used except that the crossing angle of the charging roller to the photosensitive drum 1 of the electrophotographic apparatus of Example 1-2 was 0.2 degrees. The same evaluation as in Example 1-2 was performed. The results are shown in Table 3. As shown in Table 3, image defects in actual use due to scratches on the surface of the photosensitive member where the charging roller is in contact do not occur even when the 150K sheet is used. In the photographic apparatus, high durability of the photoconductor was achieved.

  Further, when the depth of the deepest scratch was measured on the surface of the photosensitive member at the time of endurance use of 150K sheets, the average of eight measurement points in the circumferential direction of the photosensitive member was 3.2 μm.

[Example 1-13]
The electrophotographic apparatus shown in Example 1-2 was used except that the crossing angle of the charging roller to the photosensitive drum 1 of the electrophotographic apparatus of Example 1-2 was 0.7 degrees. The same evaluation was performed. The results are shown in Table 3. As shown in Table 3, image defects in actual use due to scratches on the surface of the photosensitive member where the charging roller is in contact do not occur even when the 150K sheet is used. In the photographic apparatus, high durability of the photoconductor was achieved.

  Further, when the depth of the deepest scratch was measured on the surface of the photosensitive member at the time when 150 K sheets were used, the average of eight measurement points in the circumferential direction of the photosensitive member was 1.5 μm.

[Comparative Example 1-1]
Example 1-2 except that the AC current of the charging roller to the photosensitive drum 1 of the electrophotographic apparatus of Example 1-2 is 3.0 mA / m, and the charging roller has no crossing angle of 0 degrees. Evaluation similar to Example 1-2 was performed using the electrophotographic apparatus shown in FIG. The results are shown in Table 3. As shown in Table 3, image defects due to scratches on the surface of the photosensitive member where the charging roller is in contact do not occur even after 200K sheets are endured. In an electrophotographic apparatus using the above-described AC current value, The photoconductor could be used with high durability.

  Further, when the depth of the deepest scratch was measured on the surface of the photosensitive member at the time when 150 K sheets were used, the average of eight measurement points in the circumferential direction of the photosensitive member was 2.0 μm.

[Comparative Example 1-2]
The same evaluation as in Example 1-1 was performed using the same electrophotographic apparatus as in Comparative Example 1-1 except that the AC current value of the charging roller was set to 4.0 mA / m in Comparative Example 1-1. . The results are shown in Table 3. As shown in Table 3, image defects due to scratches on the surface of the photosensitive member where the charging roller is in contact occurred with the durability of 120K sheets.

  At this time, when the depth of the deepest scratch was measured on the surface of the photoconductor, the average of 8 points measured in the circumferential direction of the photoconductor was 6.1 μm.

[Comparative Example 1-3]
Using the electrophotographic apparatus shown in Example 1-1 using the photoconductor in which the surface protective layer of Example 1-2 was not provided and the charge transport layer was formed with a thickness of 28 (μm), Example 1- Evaluation similar to 1 was performed. The results are shown in Table 3. As shown in Table 3, image defects due to scratches on the surface of the photosensitive member where the charging roller is in contact occurred with the durability of 70K sheets.

  At this time, when the depth of the deepest scratch was measured on the surface of the photoconductor, the average of 8 points measured in the circumferential direction of the photoconductor was 8.6 μm.

(Embodiment 2)
Details of other inventions will be described below.

  The electrophotographic apparatus of the present invention includes an electrophotographic photosensitive member having a conductive support and a photosensitive layer formed on the conductive support.

  The conductive support is not particularly limited as long as it has conductivity and can support the photosensitive layer.

  The photosensitive layer may be provided directly on the surface of the conductive support, or the conductive support through an appropriate other layer for improving the electrical characteristics and mechanical characteristics of the electrophotographic photosensitive member. It may be provided above.

  Further, the surface layer of the electrophotographic photosensitive member may be a part of the photosensitive layer, or may be another layer separated from the photosensitive layer.

The surface layer of the electrophotographic photosensitive member includes a compound obtained by curing a hole transporting compound having at least one polymerizable functional group, and the elastic deformation rate of the surface layer is 46% or more and 65% or less. -A monkey hardness value of 1.5 x 10 ⁸ N / m ² or more and 2.2 x 10 ⁸ N / m ² or less.

In addition, the electrophotographic apparatus of the present invention includes a roller charging member that is disposed in contact with the electrophotographic photosensitive member and charges the electrophotographic photosensitive member with discharge when a voltage is applied thereto.

Further, at the central portion of the roller charging member, the rotation axis of the roller charging member and the rotation axis of the electrophotographic photosensitive member intersect each other at an intersection angle of 0.4 degrees or more.

  The roller charging member preferably has a shape in which the outer peripheral diameter of the central portion is larger than the outer peripheral diameter of each end portion along the longitudinal direction.

  The polymerizable functional group is preferably an unsaturated polymerizable functional group represented by the following general formula (13).

｛式中、Ｅは水素原子、ハロゲン原子、置換基を有しても良いアルキル基、置換基を有しても良いアリール基、シアノ基、ニトロ基、アルコキシ基、−ＣＯＯＲ１（Ｒ１は水素原子、ハロゲン原子、置換基を有しても良いアルキル基、置換基を有しても良いアラルキル基および置換基を有しても良いアリール基）、ＣＯＮＲ２Ｒ８（Ｒ２、Ｒ８は水素原子、ハロゲン原子、置換基を有しても良いアルキル基、置換基を有しても良いアラルキル基および置換基を有しても良いアリール基を示し、互いに同一であっても異なっていてもよい）を示し、Ｗは置換基を有しても良い二価のアリーレン基または置換基を有しても良い二価のアルキレン基、−ＣＯＯ−、−Ｃ−、−Ｏ−、−ＯＯ−、−Ｓ−、−ＣＯＮＲ４−（Ｒ４は水素原子、ハロゲン原子、置換基を有しても良いアルキル基、置換基を有しても良いアラルキル基または置換基を有しても良いアリール基）を示す。ｆは０または１を示す。｝

{Wherein E is a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, a cyano group, a nitro group, an alkoxy group, -COOR1 (R1 is a hydrogen atom) , A halogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent and an aryl group which may have a substituent, CONR2R8 (R2 and R8 are a hydrogen atom, a halogen atom, An alkyl group that may have a substituent, an aralkyl group that may have a substituent, and an aryl group that may have a substituent, which may be the same or different from each other), W is a divalent arylene group which may have a substituent or a divalent alkylene group which may have a substituent, -COO-, -C-, -O-, -OO-, -S-, -CONR4- (R4 is a hydrogen atom or halogen atom) Indicates an alkyl group which may have a substituent, an aryl group) which may have a substituted or unsubstituted aralkyl group or a substituted group. f represents 0 or 1; }

 The compound having a polymerizable functional group represented by the general formula (13) is preferably a chain polymerizable compound having two or more polymerizable functional groups of the general formula (13) in one molecule.

  The polymerizable functional group is preferably any one of the general formulas (14) to (18).

  The polymerizable functional group is particularly preferably any one of the general formulas (14), (15) and (18).

  Moreover, W in the polymerizable functional group represented by the general formula (13) is an arylene group obtained by removing two hydrogens from an aromatic hydrocarbon such as benzene or naphthalene, anthracene, or pyrene, which may have a substituent. Preferably there is.

The compound obtained by curing the hole transporting compound having a polymerizable functional group is preferably one that is polymerized and cured by heat or radiation.

Moreover, it is preferable that the compound which hardened the hole transportable compound which has the said polymeric functional group was hardened | cured with the electron beam.

  The acceleration voltage of the electron beam used for curing the compound is preferably 250 KV or less.

The irradiation dose of the electron beam is preferably 1 × 10 ⁴ to 1 × 10 ⁶ Gy.

  The electrophotographic photosensitive member is preferably formed by laminating a charge generation layer and a charge transport layer in this order.

  The photosensitive layer of the electrophotographic photosensitive member is preferably formed by laminating a charge generation layer, a charge transport layer, and a protective layer in this order.

The surface layer of the electrophotographic photosensitive member, tetrafluoroethylene resin, trifluorochloroethylene resin, hexafluoro ethylene propylene resin, vinyl fluoride resin, vinylidene fluoride resin, difluoride ethylene dichloride resin and It is preferable to contain one or more of fluorine atom-containing resin particles containing these copolymers.

  The surface layer of the electrophotographic photoreceptor preferably contains conductive particles.

  The conductive particles contained in the surface layer of the electrophotographic photoreceptor are preferably metal oxides.

The elastic deformation rate of the surface layer of the photoreceptor and the HU (universal hardness value) in the present invention are obtained by applying a continuous load to the indenter and directly reading the indentation depth under the load. Measurement was performed using the required microhardness measuring device Fischerscope H100V (Fisher). The indenter used was a Vickers square pyramid diamond indenter with a face angle of 136 °. The load conditions were measured stepwise up to a final load of 6 mN (273 points with a holding time of 0.1 s for each point).

FIG. 5A shows a general relationship between the indentation depth and the load. FIG. 5B shows the result of measuring the relationship between the indentation depth and the load for the electrophotographic photosensitive member of the present invention. In both figures, the vertical axis is the load (mN) and the horizontal axis is the indentation depth h (μm). The result of increasing the load stepwise to 6 mN and then decreasing the load stepwise in the same way It is.

  The meaning of each parameter displayed in FIG. 5B is as follows.

(1) HU: Universal hardness [N / mm ² ] (2) Wt: Total work [nJ]
(3) We ... Work of elastic deformation [nJ]
(4) Wr: Work of plastic deformation [nJ]
(5) E / (1-ν2) ≈E ... Young's modulus [GPa] ν ... Poisson's ratio
(7) H plast: Hardness value of plastic deformation [N / mm ² ]
(8) hr ′: intersection of the tangent to the curve BC and the X axis [μm]

  Here, point A (FIG. 5A) is a measurement start point. A → B is a curve corresponding to indentation of the indenter. Point B is the point when the maximum set indentation depth is reached, and the value obtained by dividing the load at point B by the surface area of the indentation generated at that time is the universal hardness value (hereinafter referred to as HU). A curve of B → C is a curve corresponding to “return” after the indenter is pushed. That is, this curve corresponds to the elasticity of the measurement sample. In the curve BC, when a straight line passing through two points corresponding to 95% and 60% of the maximum load is drawn, the slope becomes the Young's modulus E empirically. If the intersection of the straight line and the x-axis is hr ′, the plastic deformation hardness value H plast is obtained as the hardness value at the indentation depth hr ′. Further, the elastic deformation work We in the measurement is represented by an area surrounded by C-B-D-C, and the plastic deformation work Wr is represented by an area enclosed by A-B-C-A. The total work Wt is We + Wr and is represented by the area surrounded by A-B-D-A.

  Here, HU is defined by the following formula (1) from the indentation depth under the same load when indented at 6 mN.

HU (N / m ² ) = Test load (N) / Vickers indenter surface area at test load (m ² )
= 6 × 10 ³ /26.43×h ² (1)
However, h: Indentation depth under test load (mm)

  The elastic deformation rate is obtained from the work (energy) performed by the indenter on the membrane, that is, the change in energy due to the increase or decrease of the load of the indenter on the membrane, and the value can be obtained from the following equation (2). The total work Wt (nW) is represented by an area surrounded by A-B-D-A in FIG. 5A, and the elastic deformation work We (nW) is surrounded by C-B-D-C. Expressed in area.

  Elastic deformation rate (%) = (We / Wt) × 100 (2)

  Generally, the hardness is expressed by the amount of deformation with respect to external stress. The smaller the amount of deformation, the higher the hardness, and the higher the HU, pencil hardness, and Vickers hardness of the surface layer of the photoreceptor, It was considered high and improved durability.

  However, the inventors of the present invention have not used all hard curable resins, such as HU, which have a fairly large value, and have not necessarily become highly durable photoconductors. In the electrophotographic apparatus, it was confirmed that durability was determined by another problem of scratches caused by durable use.

The present invention has been devised to solve the above-mentioned problems. The surface layer of an electrophotographic photosensitive member having a conductive support and a photosensitive layer formed on the support has an elastic deformation rate of 46%. 65% or less, HU (universal hardness value) 1.5 × 10 ⁸ N / m ² or more and 2.2 × 10 ⁸ N / m ² or less, arranged in contact with the electrophotographic photosensitive member, and voltage In the electrophotographic apparatus having a roller charging member that charges the electrophotographic photosensitive member by applying a voltage, a rotation axis of the roller charging member and a rotation axis of the electrophotographic photosensitive member intersect each other, and an intersection angle thereof This is achieved by using an electrophotographic apparatus having an angle of 0.4 degrees or more.

  The present inventors consider the mechanism that has solved the above-described problems by the present invention as follows.

  Endurance scratches in an electrophotographic apparatus using a roller charging method are formed by the physical properties of the surface of the photoconductor being related to each other in terms of elastic modulus, plastic deformation amount, and slipperiness, and the present invention can control each physical property. We believe that the above problems have been solved.

That is, the HU of the surface layer of the photoreceptor is less than 1.5 × 10 ⁸ N / m ² or the elastic deformation rate is 6
In the case of 5% or more, the amount of plastic deformation is large and the elastic force is large, so that paper dust, toner, or other foreign matter sandwiched between the contact member such as a cleaning blade and the photoreceptor surface It is easy to be pushed into the surface of the photosensitive member and damages the surface.

When the HU is greater than 2.2 × 10 ⁸ N / m ² or less, or the elastic deformation rate is less than 46%, it is assumed that the plastic deformation amount is conversely reduced. Paper dust, toner, or other foreign matter sandwiched between the member and the surface of the photoconductor cannot absorb the pressure caused by the powder or foreign matter on the surface of the photoconductor. Will cause scratches.

On the other hand, the present inventors use a system in which the rotating shaft of the roller charging member of the present invention and the rotating shaft of the photoreceptor intersect each other, and the intersecting angle is 0.4 degrees or more, so that the cleaning member It is considered that the frictional force between the photoreceptor surfaces can be reduced. In other words, in the present invention, the slipperiness of the drum surface works effectively within the physical property range of the drum surface, and paper dust or toner sandwiched between a contact member such as a cleaning blade and the surface of the photosensitive member. Or other foreign substances are considered to be a system that does not easily accumulate therein, or a force that is locally applied to the surface of the photoreceptor is dispersed. As a result, the HU upper limit is 2.2 × 10. We believe that we have established a system that is effective against scratches within a range of ⁸ N / m ² or less and a lower elastic deformation rate of 46%.

  That is, according to the present invention, the elastic deformation rate range, the HU value range of the photosensitive member surface layer, the rotation axis of the roller charging member and the rotation axis of the photosensitive member intersect each other, and the intersection angle is 0.4 degrees or more. By combining the systems, the synergistic effect makes it possible to find a tremendous effect with respect to the durable scratches on the photoreceptor, leading to the provision of an unprecedented highly durable photoreceptor.

  By using an electrophotographic apparatus in which the rotating shaft of the roller charging member and the rotating shaft of the electrophotographic photosensitive member intersect each other, the present inventors have developed a mechanism that can reduce the frictional force increase in the durability of the surface of the photosensitive member. I think as follows.

When the rotating shafts of the photoconductor and the charging roller are twisted, a slight peripheral speed difference is generated between the photoconductor surface and the charging roller, and the photoconductor surface is rubbed. At this time, the charging roller itself rubs against the surface of the photosensitive member and the charging roller rubs fine metal oxide particles added in the developer interposed between the surface of the photosensitive member and the charging roller. It is considered that the discharge product adsorbed on the surface of the photoconductor and / or the discharge deterioration product on the outermost surface of the photoconductor surface is removed by the action. Accordingly, it is considered that the surface of the photoreceptor can be refreshed while being discharged during image formation, and an increase in frictional force on the surface of the photoreceptor due to discharge can be suppressed.

  However, on the other hand, as shown in the present invention, deposits or deteriorated products due to discharge on the surface of the photosensitive member are caused by rubbing with a frictional force that is not so large that the rubber material used in the charging roller is twisted. As a result of further intensive studies, the present inventors considered the mechanism as follows.

  The composition of the photoreceptor surface deteriorated by discharge or the discharge product adsorbed on the surface that is inherently difficult to be scratched and scratched, satisfying the elastic deformation rate and HU which are physical property conditions of the photoreceptor surface layer, At the initial stage generated on the surface of the photoconductor, it was adsorbed with a very weak force, and the phenomenon that the force became stronger with time was confirmed. Therefore, it is considered that the discharge product on the surface of the photosensitive member can be effectively removed with a small rubbing force by performing the simultaneous discharge rubbing which is the apparatus configuration of the present invention.

In the present invention, the surface layer of the electrophotographic photosensitive member has an elastic deformation ratio of 46% to 65%, HU (universal hardness value) 1.5 × 10 ⁸ N / m ^{2 to} 2.2 × 10. ⁸ N / m ² or less is acceptable, but in particular, a hole transporting compound having one or more chain polymerizable functional groups in the same molecule and / or a product obtained by polymerizing and curing the hole transporting compound. It is effective to use. “A hole transporting compound having one or more chain polymerizable functional groups in the same molecule” refers to a compound in which a chain polymerizable functional group is chemically bonded to a part of a known hole transporting compound. . A compound having two or more polymerizable functional groups in the same molecule is preferable. Details are described in JP-A-2000-66424.

  The photosensitive layer of the present invention may be a so-called single layer type containing a charge generation material and a charge transport material, or a so-called laminated layer which is functionally separated into a charge generation layer containing a charge generation material and a charge transport layer containing a charge transport material. A mold may be used, but a stacked mold is preferred.

  The photoreceptor according to the present invention will be described below.

  The surface layer of the photoconductor of the present invention is an electrophotographic photoconductor containing a compound obtained by polymerizing or cross-linking at least one polymerizable functional group and curing, and the curing means is heat or visible light. In addition, light such as ultraviolet rays and radiation can be used. Therefore, the procedure for forming the surface layer in the present invention is a dip coating method, a spray coating method, a curtain coating method using a coating solution for dissolving or containing a compound that can be polymerized or crosslinked and cured for the surface layer. The coating is performed by a spin coating method or the like, and this is cured by the above-described curing means. The dip coating method is the best for efficient mass production of the photoreceptor, and the dip coating method is also possible in the present invention.

The structure of the photoconductor of the present invention includes a single layer type having a layer structure containing both a charge generation material and a charge transport material, or a charge generation layer containing a charge generation material and a charge transport material on a conductive substrate. The charge transport layer is either of the stacked type in which the charge transport layers are stacked in this order or in the reverse order. Furthermore, a surface protective layer can be formed on the photosensitive layer. In the present invention, at least the surface layer of the photoreceptor only needs to contain a compound that can be polymerized or crosslinked and cured by heat, light such as visible light or ultraviolet light, and radiation. However, from the viewpoint of characteristics as a photoreceptor, especially electrical characteristics such as residual potential and durability, a charge generation layer / charge transport layer is laminated in this order, or a functional separation type photoreceptor structure is laminated. A structure in which a surface protective layer is formed on the photosensitive layer is preferable.

  In the present invention, it is preferable to use radiation in the method of curing the compound for crosslinking or crosslinking the surface layer, since the residual potential does not increase without deterioration of the photoreceptor characteristics, and sufficient hardness can be exhibited. .

At this time, the radiation used is an electron beam and a γ-ray. In the case of electron beam irradiation, any type of accelerator such as a scanning type, an electro curtain type, a broad beam type, a pulse type, and a laminar type can be used. In the case of irradiating an electron beam, the acceleration voltage is preferably 250 kV or less, and optimally 150 kV or less, in order to develop the electrical characteristics and durability of the photoreceptor of the present invention. The irradiation dose is preferably in the range of 1 × 10 ⁴ to 1 × 10 ⁶ Gy, more preferably in the range of 3 × 10 ^{4 to} 5 × 10 ⁵ Gy. If the accelerating voltage exceeds the above, the electron beam irradiation damage tends to increase on the characteristics of the photoreceptor. In addition, when the irradiation dose is less than the above range, the curing tends to be insufficient, and when the dose is high, the photoreceptor characteristics are likely to be deteriorated.

  Surface layer compounds that can be polymerized or crosslinked and cured include unsaturated polymerizable functional groups in the molecule from the standpoints of high reactivity, high reaction rate, and high hardness achieved after curing. Those having a group are preferred, and among them, compounds having an acrylic group, a methacryl group, and a styrene group are particularly preferred.

In the present invention, the compound having an unsaturated polymerizable functional group is roughly classified into a monomer and an oligomer by repeating the structural unit. The monomer means that the structural unit having an unsaturated polymerizable functional group is not repeated, and indicates a relatively small molecular weight, and the oligomer is a structural unit having an unsaturated polymerizable functional group having about 2 to 20 repeating units. It is a polymer. Also, a macromonomer having an unsaturated polymerizable functional group only at the terminal of the polymer or oligomer can be used as the curable compound for the surface layer of the present invention.

  In addition, the compound having an unsaturated polymerizable functional group in the present invention is preferably a charge transport compound in order to satisfy the charge transport function necessary for the surface layer. Among these, an unsaturated polymerizable compound having a hole transport function is more preferable.

  Next, the photosensitive layer of the electrophotographic photoreceptor according to the present invention will be described.

  The support for the electrophotographic photosensitive member may be any material having conductivity, for example, a metal or alloy such as aluminum, copper, chromium, nickel, zinc and stainless steel formed into a drum or sheet, aluminum and copper. Metal foil such as laminated on plastic film, aluminum, indium oxide, tin oxide, etc. deposited on plastic film, metal with conductive layer applied alone or with binder resin, or plastic Examples include films and paper.

  In the present invention, an undercoat layer having a barrier function and an adhesive function can be provided on the conductive support.

  The undercoat layer is used for improving the adhesion of the photosensitive layer, improving the coatability, protecting the support, covering defects on the support, improving the charge injection from the support, and protecting the photosensitive layer from electrical breakdown. Formed for. Materials for the undercoat layer include polyvinyl alcohol, poly-N-vinylimidazole, polyethylene oxide, ethyl cellulose, ethylene-acrylic acid copolymer, casein, polyamide, N-methoxymethylated 6 nylon, copolymer nylon, glue and gelatin Can be used. These are dissolved in a solvent suitable for each and coated on a support. The film thickness at that time is preferably 0.1 to 2 μm.

When the photoreceptor of the present invention is a function separation type photoreceptor, a charge generation layer and a charge transport layer are laminated. Examples of the charge generation material used in the charge generation layer include selenium-tellurium, pyrylium, thiapyrylium dyes, various central metals and crystal systems, specifically, crystal types such as α, β, γ, ε, and X types. Phthalocyanine compounds, anthanthrone pigments, dibenzpyrenequinone pigments, pyranthrone pigments, trisazo pigments, disazo pigments, monoazo pigments, indigo pigments, quinacridone pigments, asymmetrical quinocyanine pigments, quinocyanines and JP-A No. 54-143645 Examples thereof include amorphous silicone.

  In the case of a functionally separated type photoreceptor, the charge generation layer is formed of the charge generation material, such as a homogenizer, an ultrasonic dispersion, a ball mill, a vibration ball mill, a sand mill, an attritor, a roll mill, etc. It is well dispersed by the method, and is formed by applying a dispersion and drying, or formed as a single composition film such as a vapor deposition film of the charge generation material. The film thickness is preferably 5 μm or less, and particularly preferably in the range of 0.1 to 2 μm.

  What can be used as the binder resin is a polymer or copolymer of vinyl compounds such as styrene, vinyl acetate, vinyl chloride, acrylic acid ester, methacrylic acid ester, vinylidene fluoride, trifluoroethylene, polyvinyl alcohol, Examples include polyvinyl acetal, polycarbonate, polyester, polysulfone, polyphenylene oxide, polyurethane, cellulose resin, phenol resin, melamine resin, silicon resin, and epoxy resin.

  As the surface layer in the present invention, the above-described charge transport layer on the charge generation layer or the protective layer after forming the charge transport layer made of the charge transport material and the binder resin on the charge generation layer is applied thereto.

As the surface layer, one containing a compound having at least one polymerizable functional group or one containing a hole transporting compound having an unsaturated polymerizable functional group can be used, which is polymerized, It can be cured and used. However, in the present invention, the mechanical properties of the surface layer are elastic deformation ratios of 46% or more and 65% or less, HU (universal hardness value) 1.5 × 10 ⁸ N / m ² or more and 2.2 × 10 ⁸ N / m ² or less is acceptable, and the material is not limited to these materials.

Among the compounds shown in Table 4 and Table 5 , No. 1 to No. 33, and no. Indicated by 40
Are exemplified as compounds having at least one polymerizable functional group that can be used in the surface layer of the photoreceptor of the present invention.

When the protective layer is used as a surface layer, the charge transport layer corresponding to the lower layer is a suitable charge transport material, for example, a polymer compound having a heterocyclic ring such as poly-N-vinylcarbazole or polystyrylanthracene, or a condensed polycyclic aromatic compound. , Heterocyclic compounds such as pyrazoline, imidazole, oxazole, triazole, carbazole, triarylalkane derivatives such as triphenylmethane, triarylamine derivatives such as triphenylamine, phenylenediamine derivatives, N-phenylcarbazole derivatives, stilbene derivatives, hydrazones A solution in which a low molecular weight compound such as a derivative is dispersed / dissolved in a solvent together with a suitable binder resin (can be selected from the above-mentioned resins for charge generation layers) is applied and dried by the above-mentioned known methods. Can do. In this case, the ratio of the charge transport material to the binder resin is preferably selected in the range of 30 to 100, preferably 50 to 100, when the total weight of both is 100.
When the amount of the charge transport material is less than that, the charge transport ability is lowered, and problems such as a decrease in sensitivity and an increase in residual potential occur. Also in this case, the film thickness of the photosensitive layer is in the range of 5 to 30 μm, and the film thickness of the photosensitive layer at this time is the total thickness of the charge generation layer, the charge transport layer, and the surface protective layer. is there.

  In any case, the surface layer is generally formed by a polymerization / curing reaction after applying the solution containing the hole transporting compound, but the solution containing the hole transporting compound is prepared in advance. It is also possible to form a surface layer using a material obtained by reacting to obtain a cured product and then again dispersing or dissolving in a solvent. As a method for applying these solutions, for example, a dip coating method, a spray coating method, a curtain coating method, a spin coating method and the like are known, but the dip coating method is preferable from the viewpoint of efficiency / productivity.

  The surface layer in the present invention can contain fluorine atom-containing resin particles.

  Fluorine atom-containing resin particles include tetrafluoroethylene resin, trifluoroethylene chloride resin, hexafluoroethylene propylene resin, vinyl fluoride resin, vinylidene fluoride resin, ethylene difluoride dichloride resin, and their co-polymers. One or two or more types are preferably selected from the combination, but tetrafluoroethylene resin and vinylidene fluoride resin are particularly preferable. The molecular weight of the resin particles and the particle size of the particles can be appropriately selected and are not particularly limited.

  The proportion of fluorine atom-containing resin particles in the surface layer is preferably 5 to 70% by weight, more preferably 10 to 60% by weight, based on the total weight of the surface layer. If the proportion of fluorine atom-containing resin particles is more than 70% by weight, the mechanical strength of the surface layer tends to decrease, and if the proportion of fluorine atom-containing resin particles is less than 5% by weight, the surface layer surface releasability, surface layer In some cases, the wear resistance and scratch resistance are not sufficient.

  In the present invention, additives such as radical scavengers and antioxidants may be added to the surface layer for the purpose of further improving dispersibility, binding properties and weather resistance.

  The film thickness of the surface protective layer used in the present invention is preferably in the range of 0.2 to 10 μm, more preferably in the range of 0.5 to 6 μm.

  An electrophotographic apparatus that forms an image using the photoconductor prepared as described above will be described below.

  Hereinafter, the present invention will be described in more detail with reference to examples.

  In addition, with respect to the roller charging device employed in the second embodiment (Example 2), the photosensitive drum of the member to be charged, and the hardware configuration of the electrophotographic apparatus including these, an overview and basics shown in FIGS. The functions are almost the same as those employed in the first embodiment (Example 1). For this reason, in Embodiment 2 (Example 2), about the structural member which has the structure and function equivalent to Embodiment 1 (Example 1), while using the same member number, the overlapping description about the member is the same. Omitted.

(Example 2)
[Example 2-1]
(Photoconductor manufacturing method)
Hereinafter, “part” in Example 2 means “part by mass”.

  The photosensitive drum 1 shown in FIGS. 1 to 4 of the present invention was prepared as follows.

  First, the coating material for conductive layers was prepared by the following procedure. 50 parts of conductive titanium oxide powder coated with tin oxide containing 10% antimony oxide, 25 parts of phenol resin, 20 parts of methyl cellosolve, 5 parts of methanol and silicone oil (polydimethylsiloxane polyoxyalkylene copolymer, average 0.002 part of molecular weight 3000) was prepared by dispersing for 2 hours in a sand mill using φ1 mm glass beads. This paint was applied onto an aluminum cylinder having a diameter of 30 mm × 357.5 mm by a dip coating method and dried at 140 ° C. for 30 minutes to form a conductive layer having a film thickness of 16 μm.

  Next, 5 parts of N-methoxymethylated nylon was dissolved in 95 parts of methanol to prepare an intermediate layer coating solution. This coating solution was applied onto the conductive layer by a dip coating method and dried at 100 ° C. for 20 minutes to form an intermediate layer having a thickness of 0.6 μm.

  Next, the Bragg angles (2θ ± 0.2 °) in CuKα characteristic X-ray diffraction are 7.5 °, 9.9 °, 16.3 °, 18.6 °, 25.1 °, and 28.3 °. Disperse 10 parts of crystalline hydroxygallium phthalocyanine having a strong peak, 5 parts of polyvinyl butyral (trade name: Esletk BX-1, manufactured by Sekisui Chemical Co., Ltd.) and 250 parts of cyclohexanone for 3 hours in a sand mill using φ1 mm glass beads. Thereafter, 250 parts of ethyl acetate was added to prepare a charge generation layer coating solution. This coating solution was applied onto the intermediate layer by a dip coating method and dried at 100 ° C. for 15 minutes to form a charge generation layer having a thickness of 0.2 μm.

Next , 7 parts of a charge transport material which is a styryl compound and 10 parts of polycarbonate (weight average molecular weight = 46000) are dissolved in a mixed solvent of 28 parts of methylal / 65 parts of monochlorobenzene to prepare a solution. Was dip coated on the surface of the charge generation layer and dried at 120 ° C. for 60 minutes to form a charge transport layer having a thickness of 10 μm.

Next, Compound Example Nos. 40 parts of the compound shown in No. 12 were dissolved in a mixed solvent of 60 parts of n-propanol to prepare a coating material for the surface protective layer. This paint is applied on the above charge transport layer by dip coating, dried at 50 ° C. for 15 minutes, and then an electron beam with an oxygen concentration of 10 ppm or less under the conditions of an acceleration voltage of 150 kV and an absorbed electron dose of 5 × 10 ⁴ Gy. The film was irradiated with a nitrogen atmosphere and heated and dried at 100 ° C. for 10 minutes in the same atmosphere to cure the compound, thereby forming a surface protective layer having a thickness of 5 μm, and an electrophotographic photosensitive member was produced.

  A photoconductor produced under the same conditions as this photoconductor was allowed to stand in an environment of a temperature of 25 ° C. and a humidity of 50% for 24 hours, and then elastically deformed using the above-described hardness measuring device Fischerscope H100V (Fischer). Rates and HU were determined. The values are shown in Table 6.

<Configuration of charging roller>
The charging roller 2 has a conductive EPDM rubber formed on a stainless steel core and a surface layer formed on the surface.

In this embodiment, the width of the charging roller 2 in pressure contact with the photosensitive drum 1 is 32 cm, and the AC current to the photosensitive drum 1 is about 5.8 mA / m ² (= electrophotographic apparatus during image formation). Total AC current value flowing from the main body high-voltage power supply to the charging roller: 1850 μA / charging roller length: 3
2 cm).

  The pressure contact pressure of the roller charging device 2 to the photosensitive drum 1 was 0.7 kgf as the pressure springs at both ends. Further, the own weight of the charging roller 2 was about 0.15 kg. At this time, a pressure sensor was installed so as to replace the outer peripheral surface of the photosensitive drum 1 and the total pressure applied by the charging roller 2 to the photosensitive drum 1 was measured. The value was about 1.55 kg, The pressure was about 4.84 kg / m.

  The linear pressure described here is the total pressure (unit: g) of the contact pressure of the charging roller 2 with respect to the photosensitive drum 1, as shown in FIG. mm). Since the total pressure of the contact pressure of the charging roller 2 against the photosensitive drum 1 is affected by the weight of the charging roller 2 depending on the pressing direction even if the charging roller 2 is pressed using a pressure spring, It is necessary to perform measurement in a state where a pressure spring or the like is actually incorporated in the charging device 10 or in a state where the charging device 10 is incorporated in an electrophotographic apparatus or the like.

  In this embodiment, the crossing angle between the charging roller and the photosensitive drum was set to 0.4 °.

  The electrophotographic apparatus was installed in a normal temperature and humidity environment (20 ° C., 50% RH), and an endurance test was conducted to examine the scratches generated on the surface of the photosensitive layer. The results are shown in Table 6. As shown in Table 6, image defects caused by scratches on the surface of the photosensitive member where the charging roller is in contact do not occur even after 200K sheets are endured. In addition, it was possible to achieve a long-life photoconductor with both scratches.

  Further, when the depth of the deepest scratch was measured on the surface of the photosensitive member at the time when 200 K sheets were used, the average of eight points in the circumferential direction of the photosensitive member was 1.3 μm.

[Example 2-2]
The charge transport layer in Example 2-1 was changed, and a photoreceptor without a protective layer was produced as follows.

Compound example NO. 11 was dissolved in a mixed solvent of 15 parts of dichloromethane and 40 parts of toluene to prepare a coating material for charge transport. This paint is applied onto the charge generation layer by dip coating, dried at 50 ° C. for 15 minutes, and then subjected to an electron beam in a nitrogen atmosphere under conditions of an acceleration voltage of 150 kV and an absorbed electron dose of 5 × 10 ⁴ Gy. Irradiate, heat dry at 100 ° C. for 10 minutes under the same atmosphere, and further dry at 100 ° C. for 60 minutes to cure the compound, thereby forming a charge transport layer having a film thickness of 18 μm, and producing an electrophotographic photosensitive member did.

  A photoconductor produced under the same conditions as this photoconductor was allowed to stand in an environment of a temperature of 25 ° C. and a humidity of 50% for 24 hours, and then elastically deformed using the above-described hardness measuring apparatus Fischerscope H100V (Fischer). Rates and HU were determined. The values are shown in Table 6.

  The photoconductor produced in this way was evaluated in the same manner as in Example 2-1, using the electrophotographic apparatus shown in Example 2-1. The results are shown in Table 6. As shown in Table 6, the image defect due to the scratch on the surface of the photosensitive member where the charging roller is in contact does not occur even when the 200K sheet is endured. In the above-described electrophotographic apparatus using the AC current value, High durability of the photoreceptor was achieved.

  Further, when the depth of the deepest scratch was measured on the surface of the photosensitive member at the time when 200K sheets were used for durability, the average of eight measurement points in the circumferential direction of the photosensitive member was 1.4 μm.

[ Reference Example 1 ]
A photoconductor was prepared by the same configuration and method as in Example 2-1, except that the surface protective layer in Example 2-1 was changed as follows.

No. in Table 6 10 parts of the compound containing 34 acryloyloxy groups were dissolved in a mixed solvent of 60 parts of dichloromethane / 120 parts of toluene together with 10 parts of the styryl compound contained in the charge transport layer shown in Example 2-2, and used for the surface protective layer. A paint was prepared. This paint was applied on the charge transport layer by spray coating, dried at 120 ° C. for 60 minutes, and then irradiated with an electron beam under a nitrogen atmosphere under an acceleration voltage of 150 kV absorbed electron dose of 5 × 10 ⁴ Gy. Under the same atmosphere, it was heated and dried at 100 ° C. for 10 minutes, further dried at 100 ° C. for 60 minutes, and the compound was cured to form a surface protective layer having a film thickness of 5 μm, thereby producing a photoreceptor.

  A photoconductor produced under the same conditions as this photoconductor was allowed to stand in an environment of a temperature of 25 ° C. and a humidity of 50% for 24 hours, and then elastically deformed using the above-described hardness measuring apparatus Fischerscope H100V (Fischer). Rates and HU were determined. The values are shown in Table 6.

  This photoreceptor was evaluated in the same manner as in Example 2-1, using the electrophotographic apparatus shown in Example 2-1. The results are shown in Table 6. As shown in Table 6, image defects caused by scratches on the surface of the photosensitive member where the charging roller is in contact do not occur even after 200K sheets are endured. In the electrophotographic apparatus using the above-described AC current value, High durability of the photoconductor was achieved.

  Further, when the depth of the deepest scratch was measured on the surface of the photosensitive member when 200K sheets were used for durability, the average of eight points in the circumferential direction of the photosensitive member was 2.6 μm.

[Example 2-4]
The compound of Table 4 or Table 5 used in the surface protective layer of Example 2-1 was prepared as Example No. A surface protective layer and a photosensitive layer were prepared by the same configuration and method as in Example 2-1, except that 14 (Table 4) was used.

  A photoconductor produced under the same conditions as this photoconductor was allowed to stand in an environment of a temperature of 25 ° C. and a humidity of 50% for 24 hours, and then elastically deformed using the above-described hardness measuring apparatus Fischerscope H100V (Fischer). Rates and HU were determined. The values are shown in Table 6.

  This photoreceptor was evaluated in the same manner as in Example 2-1, using the electrophotographic apparatus shown in Example 2-1. The results are shown in Table 6. As shown in Table 6, image defects caused by scratches on the surface of the photosensitive member where the charging roller is in contact do not occur even after 200K sheets are endured. In the electrophotographic apparatus using the above-described AC current value, High durability of the photoconductor was achieved.

  Further, when the depth of the deepest scratch was measured on the surface of the photosensitive member at the time when 200 K sheets were used, the average of eight points measured in the circumferential direction of the photosensitive member was 1.9 μm.

[Example 2-5]
4 parts of polytetrafluoroethylene fine particles (particle size: 0.18 μm) were added to the coating material for the surface protective layer of Example 2-1, and compound example No. 12 was dissolved together with 36 parts of the compound shown in 12 in a solvent of 60 parts of n-propanol to prepare a coating material for the surface protective layer. This paint was applied onto the charge transport layer by a dip coating method, dried at 50 ° C. for 15 minutes, and then irradiated with an electron beam under a nitrogen atmosphere under an acceleration voltage of 150 kV absorbed electron dose of 5 × 10 ⁴ Gy. 100 ° C in the same atmosphere
And dried at 100 ° C. for 60 minutes to cure the compound, thereby forming a surface protective layer having a thickness of 5 μm, and an electrophotographic photosensitive member was produced.

  A photoconductor produced under the same conditions as this photoconductor was allowed to stand in an environment of a temperature of 25 ° C. and a humidity of 50% for 24 hours, and then elastically deformed using the above-described hardness measuring apparatus Fischerscope H100V (Fischer). Rates and HU were determined. The values are shown in Table 6.

  This photoreceptor was evaluated in the same manner as in Example 2-1, using the electrophotographic apparatus shown in Example 2-1. The results are shown in Table 6. As shown in Table 6, image defects caused by scratches on the surface of the photosensitive member where the charging roller is in contact do not occur even after 200K sheets are endured. In the electrophotographic apparatus using the above-described AC current value, High durability of the photoconductor was achieved.

  Further, when the depth of the deepest scratch was measured on the surface of the photosensitive member at the time when 200K sheets were used for durability, the average of eight measurement points in the circumferential direction of the photosensitive member was 1.1 μm.

[Example 2-6]
Surface protection with the same configuration and method as in Example 2-1 except that the absorbed electron dose in Example 2-1 was changed to 4 × 10 ⁵ Gy and changed to post-heat treatment in the air after electron beam irradiation. A photosensitive member was prepared by preparing a layer and a photosensitive layer.

  A photoconductor produced under the same conditions as this photoconductor was allowed to stand in an environment of a temperature of 25 ° C. and a humidity of 50% for 24 hours, and then elastically deformed using the above-described hardness measuring device Fischerscope H100V (Fischer). Rates and HU were determined. The values are shown in Table 6.

  This photoreceptor was evaluated in the same manner as in Example 2-1, using the electrophotographic apparatus shown in Example 2-1. The results are shown in Table 6. As shown in Table 6, image defects caused by scratches on the surface of the photosensitive member where the charging roller is in contact do not occur even after 200K sheets are endured. In the electrophotographic apparatus using the above-described AC current value, High durability of the photoconductor was achieved.

Further, when the depth of the deepest scratch was measured on the surface of the photosensitive member at the time when 200K sheets were used, it was 3.0 μm in the average of eight measurement points in the circumferential direction of the photosensitive member. [Example 2-7]
A photosensitive member having the same photosensitive layer and surface protective layer as in Example 2-1 was prepared.

This photoreceptor was evaluated in the same manner as in Example 2-1, with the AC current value of the charging roller of the electrophotographic apparatus in Example 2-1 set to 6.2 mA / m. The results are shown in Table 6. As shown in Table 6, image defects caused by scratches on the surface of the photosensitive member where the charging roller is in contact do not occur even after 200K sheets are endured. In the electrophotographic apparatus using the above-described AC current value, High durability of the photoconductor was achieved.

  Further, when the depth of the deepest scratch was measured on the surface of the photoconductor when 200K sheets were used for durability, the average of eight points in the circumferential direction of the photoconductor was 1.5 μm.

[Example 2-8]
A surface protective layer and a photosensitive layer were prepared by the same configuration and method as in Example 2-1, except that the pressure of the charging roller of the electrophotographic apparatus in Example 2-1 was about 5 kg / m, and a photoconductor was prepared. did.

  A photoconductor produced under the same conditions as this photoconductor was allowed to stand in an environment of a temperature of 25 ° C. and a humidity of 50% for 24 hours, and then elastically deformed using the above-described hardness measuring device Fischerscope H100V (Fischer). Rates and HU were determined. The values are shown in Table 6.

This photoreceptor was evaluated in the same manner as in Example 2-1, using the electrophotographic apparatus shown in Example 2-1. The results are shown in Table 6. As shown in Table 6, image defects caused by scratches on the surface of the photosensitive member where the charging roller is in contact do not occur even after 200K sheets are endured. In the electrophotographic apparatus using the above-described AC current value, High durability of the photoconductor was achieved.

  Further, when the depth of the deepest scratch was measured on the surface of the photosensitive member at the time when 200K sheets were used for durability, the average of eight measurement points in the circumferential direction of the photosensitive member was 1.1 μm.

[Example 2-9]
The compound of Table 4 or Table 5 used in the surface protective layer of Example 2-1 was prepared as Example No. Instead of 40 (Table 5), a surface protective layer and a photosensitive layer were prepared by the same configuration and method as in Example 2-1 except that the absorbed electron dose was changed to 4 × 10 ⁵ Gy to prepare a photoreceptor.

  A photoconductor produced under the same conditions as this photoconductor was allowed to stand in an environment of a temperature of 25 ° C. and a humidity of 50% for 24 hours, and then elastically deformed using the above-described hardness measuring apparatus Fischerscope H100V (Fischer). Rates and HU were determined. The values are shown in Table 6.

  This photoreceptor was evaluated in the same manner as in Example 2-1, using the electrophotographic apparatus shown in Example 2-1. The results are shown in Table 6. As shown in Table 6, image defects caused by scratches on the surface of the photosensitive member where the charging roller is in contact do not occur even after 200K sheets are endured. In the electrophotographic apparatus using the above-described AC current value, High durability of the photoconductor was achieved.

  Further, when the depth of the deepest scratch was measured on the surface of the photoreceptor when 200K sheets were used for durability, the average of 8 points measured in the circumferential direction of the photoreceptor was 1.2 μm.

[Comparative Example 2-1]
A surface protective layer and a photosensitive layer were prepared by the same configuration and method as in Example 2-1 except that there was no crossing angle between the charging roller and the photosensitive drum of the electrophotographic apparatus in Example 2-1, and a photoconductor was prepared. Created.

  Table 6 shows the results of evaluation of the photoconductor as in Example 2-1. As shown in Table 6, an image defect due to scratches on the portion of the photoreceptor surface where the charging roller is in contact occurred with the durability of 130K sheets.

  At this time, when the depth of the deepest scratch was measured on the surface of the photoreceptor, the average of 8 points measured in the circumferential direction of the photoreceptor was 6.0 μm.

[Comparative Example 2-2]
The surface protective layer and the photosensitive layer were formed by the same configuration and method as in Example 2-1, except that the crossing angle between the charging roller and the photosensitive drum of the electrophotographic apparatus in Example 2-1 was changed to 0.3 °. A photoreceptor was prepared.

  Table 6 shows the results of evaluation of the photoconductor as in Example 2-1. As shown in Table 6, an image defect due to scratches on the portion of the photoreceptor surface where the charging roller is in contact occurred with the durability of 190K sheets.

  At this time, when the depth of the deepest scratch on the surface of the photoconductor was measured, an average of 8 points measured in the circumferential direction of the photoconductor was 4.2 μm.

[Comparative Example 2-3]
Using the electrophotographic apparatus shown in Example 2-1, using the photoconductor of Example 2-1 having no surface protective layer and having a charge transport layer formed with a thickness of 28 (μm), Example 2- Evaluation similar to 1 was performed. The results are shown in Table 6. As shown in Table 6, image defects due to scratches on the portion of the photoreceptor surface where the charging roller is in contact occurred with the durability of 70K sheets.

  At this time, when the depth of the deepest scratch was measured on the surface of the photoconductor, the average of 8 points measured in the circumferential direction of the photoconductor was 8.6 μm.

[Comparative Example 2-4]
Example 2-1 except that the absorbed electron dose in Example 2-6 was changed to 1 × 10 ⁵ Gy
A surface protective layer and a photosensitive layer were prepared by the same configuration and method as described above to prepare a photoreceptor.

  The photoreceptor was allowed to stand in an environment of a temperature of 25 ° C. and a humidity of 50% for 24 hours, and then the elastic deformation rate and HU were determined using the above-described hardness measuring apparatus Fischerscope H100V (Fischer). The values are shown in Table 6.

  Table 6 shows the results of evaluation of the photoconductor as in Example 2-1. As shown in Table 6, an image defect due to scratches on the portion of the photoreceptor surface where the charging roller is in contact occurred with the durability of 170K sheets.

  At this time, when the depth of the deepest scratch on the surface of the photoconductor was measured, an average of 8 points measured in the circumferential direction of the photoconductor was 9.2 μm.

[Comparative Example 2-5]
The compound of Table 4 or Table 5 used in the surface protective layer of Example 2-1 was prepared as Example No. The surface protective layer and the photosensitive layer were prepared by the same configuration and method as Example 2-1 except that the film thickness was changed to 36 (Table 5) and a film having a film thickness of 1 μm was formed to prepare a photoreceptor.

  A photoconductor produced under the same conditions as this photoconductor was allowed to stand in an environment of a temperature of 25 ° C. and a humidity of 50% for 24 hours, and then elastically deformed using the above-described hardness measuring apparatus Fischerscope H100V (Fischer). Rates and HU were determined. The values are shown in Table 6.

Table 6 shows the results of evaluation of the photoconductor as in Example 2-1. As shown in Table 6, image defects due to scratches on the surface of the photosensitive member where the charging roller is in contact occurred with the durability of 180K sheets.

  At this time, when the depth of the deepest scratch on the surface of the photoconductor was measured, the average of 8 points measured in the circumferential direction of the photoconductor was 4.1 μm.

[Comparative Example 2-6]
After forming the charge transport layer in Comparative Example 2-3, 1 part by weight of hydrophobic silica particles in a solution prepared by dissolving 10 parts of the polycarbonate resin used in the charge transport layer in a mixed solvent of 100 parts of monochlorobenzene and 60 parts of dichloromethane. A coating solution obtained by mixing and dispersing the above was applied onto the CTL with a spray coater to form a protective layer having a thickness of 1.0 μm after drying to produce a photoreceptor. The photoreceptor was allowed to stand in an environment of a temperature of 25 ° C. and a humidity of 50% for 24 hours, and then the elastic deformation rate and HU were determined using the above-described hardness measuring apparatus Fischerscope H100V (Fischer). The values are shown in Table 6.

  Table 6 shows the results of evaluation of the photoconductor as in Example 2-1. As shown in Table 6, image defects due to scratches on the surface of the photosensitive member where the charging roller is in contact occurred with the durability of 160K sheets.

At this time, when the depth of the deepest scratch was measured on the surface of the photoconductor, the average of 8 points measured in the circumferential direction of the photoconductor was 5.1 μm.

[Comparative Example 2-7]
The same surface protective layer and photosensitive layer as those in Comparative Example 2-1 were prepared to prepare a photoconductor, and the AC current value of the charging roller of the electrophotographic apparatus in Comparative Example 2-1 was changed to 4.8 mA / m ^2. The photoreceptor was evaluated by the same configuration and method as in Example 2-1. The results are shown in Table 6. As shown in Table 6, the image defect due to the scratch on the surface of the photosensitive member where the charging roller is in contact with the surface was not damaged.

  At this time, when the depth of the deepest scratch was measured on the surface of the photoreceptor, the average of 8 points measured in the circumferential direction of the photoreceptor was 2.8 μm.

1 is a front view showing a roller charging device according to an embodiment of the present invention and a photosensitive drum of a member to be charged. FIG. 2 is a sectional view taken along line AA in FIG. 1. The plane which looked at the charging roller and photosensitive drum of the roller charging device of FIG. Schematic which shows the electrophotographic apparatus concerning the embodiment. The graph which shows the relationship between indentation depth and a load. The front view which shows the conventional drum charging device and the photosensitive drum of a to-be-charged body. AA line sectional view of Drawing 6. The top view which looked at the charging roller and photosensitive drum of the roller charging device of FIG. The graph showing the charging efficiency example in contact charging.

Explanation of symbols

1 Photoconductor (Photosensitive drum)
DESCRIPTION OF SYMBOLS 1a Conductive base | substrate 1b Layer containing both a charge generation material and a charge transport material 1c Surface protective layer 2 Contact charging member (charging roller)
2a conductive core 2b conductive elastic layer (conductive rubber)
2c Surface coating layer 10 Roller charging device 12 Cleaner 13 Control means (control device)
23 Laser Scanner 24 Developer 25 Cassette 26 Paper Feed Roller 27 Timing Roller 28 Transfer Roller 29 Fixing Device 30 Paper Discharge Roller 31 Paper Discharge Tray

Claims (16)

Curing the hole-transporting compound conductive support and and the surface layer comprising an electrophotographic photosensitive member having a photosensitive layer formed on the conductive substrate has at least one polymerizable functional group An electrophotographic photoreceptor containing the compound,
The electrophotographic photosensitive member disposed in contact, an electrophotographic apparatus having a roller charging member for charging said electrophotographic photosensitive member, at least by a voltage being applied to,
AC current from the roller charging member to the conductive support of the electrophotographic photosensitive member is not less 4mA / m or more and the roller at the central portion of the charging member, the rotation shaft and the electrophotographic photosensitive of the roller charging member An electrophotographic apparatus in which the rotation axis of the body intersects each other.   The electrophotographic apparatus according to claim 1, wherein both ends of the roller charging member are pressed against the electrophotographic photosensitive member with a pressurizing force of 5 kg / m or more. Curing the hole-transporting compound conductive support and and the surface layer comprising an electrophotographic photosensitive member having a photosensitive layer formed on the conductive substrate has at least one polymerizable functional group The elastic deformation rate of the surface layer is 46% or more and 65% or less, and the universal hardness value is 1.5 × 10 ⁸ N / m ² or more and 2.2 × 10 ⁸ N / m ² or less. An electrophotographic photoreceptor,
The electrophotographic disposed in contact with the photosensitive member, and at least with an electrophotographic apparatus and a roller charging member, the charging the said electrophotographic photosensitive member with a discharge when a voltage is applied,
The roller in the central portion of the charging member, and the rotation axis of the rotary shaft and the electrophotographic photosensitive member of the roller charging member, an electrophotographic apparatus which intersect each other at an intersection angle of at least 0.4 degrees.   The electrophotographic apparatus according to claim 1, wherein the roller charging member has a shape in which an outer peripheral diameter of a central portion is larger than an outer peripheral diameter of each end portion along a longitudinal direction. The electrophotographic apparatus according to claim 1, wherein the polymerizable functional group is an unsaturated polymerizable functional group represented by the following general formula (1).

{Wherein E is a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, a cyano group, a nitro group, an alkoxy group, -COOR1 (R1 is a hydrogen atom) , A halogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent and an aryl group which may have a substituent, CONR2R8 (R2 and R8 are a hydrogen atom, a halogen atom, An alkyl group that may have a substituent, an aralkyl group that may have a substituent, and an aryl group that may have a substituent, which may be the same or different from each other), W is a divalent arylene group which may have a substituent or a divalent alkylene group which may have a substituent, -COO-, -C-, -O-, -OO-, -S-, -CONR4- (R4 is a hydrogen atom or halogen atom) Indicates an alkyl group which may have a substituent, an aryl group) which may have a substituted or unsubstituted aralkyl group or a substituted group. f represents 0 or 1; } 6. The electrophotography according to claim 5 , wherein the compound having a polymerizable functional group represented by the general formula (1) is a chain polymerizable compound having two or more polymerizable functional groups of the general formula (1) in one molecule. apparatus. The electrophotographic apparatus according to claim 5, wherein the polymerizable functional group is any one of general formulas (2) to (6).

  The electrophotographic apparatus according to claim 7, wherein the polymerizable functional group is any one of general formulas (2), (3), and (6). W in the polymerizable functional group represented by formula (1) is, is an arylene group obtained by removing two hydrogen also benzene or naphthalene, anthracene, aromatic hydrocarbons pyrene substituted The electrophotographic apparatus according to claim 5 or 6 . Said electrophotographic photosensitive member, a charge generation layer and a charge transport layer, the electrophotographic apparatus according to any one of claims 1 to 9 which has been formed by laminating in this order. The electrophotographic apparatus according to claim 10, wherein the photosensitive layer of the electrophotographic photoreceptor is configured by laminating a charge generation layer, a charge transport layer, and a protective layer in this order. The surface layer of the electrophotographic photoreceptor is composed of tetrafluoroethylene resin, trifluorinated ethylene chloride resin, hexafluoroethylene propylene resin, vinyl fluoride resin, vinylidene fluoride resin, ethylene difluoride dichloride resin, and these the electrophotographic apparatus according to any one of claims 1 to 11, containing one or two or more fluorine-containing resin particles containing the copolymer. The electrophotographic apparatus according to any one of claims 1 to 12 surface layer of the electrophotographic photosensitive member containing conductive particles. The electrophotographic apparatus according to claim 13 , wherein the conductive particles contained in the surface layer of the electrophotographic photosensitive member are metal oxides. Curing the hole-transporting compound conductive support and and the surface layer comprising an electrophotographic photosensitive member having a photosensitive layer formed on the conductive substrate has at least one polymerizable functional group An electrophotographic photoreceptor containing the compound,
The electrophotographic disposed in contact with the photosensitive member, by being applied a voltage having at least a roller charging member for charging said electrophotographic photosensitive member, the,
A process cartridge provided integrally and detachably in the electrophotographic apparatus main body,
AC current from the roller charging member to the conductive support of the electrophotographic photosensitive member is not less 4mA / m or more and the roller at the central portion of the charging member, the rotation shaft and the electrophotographic photosensitive of the roller charging member A process cartridge that intersects with the rotation axis of the body. Curing the hole-transporting compound conductive support and and the surface layer comprising an electrophotographic photosensitive member having a photosensitive layer formed on the conductive substrate has at least one polymerizable functional group The elastic deformation rate of the surface layer is 46% or more and 65% or less, and the universal hardness value is 1.5 × 10 ⁸ N / m ² or more and 2.2 × 10 ⁸ N / m ² or less. An electrophotographic photoreceptor,
The electrophotographic disposed in contact with the photosensitive member has a roller charging member for charging said electrophotographic photosensitive member with a discharge when a voltage is applied, at least,
A process cartridge provided integrally and detachably in the electrophotographic apparatus main body,
The in the center of the roller charging member, a process cartridge and rotation axis of the rotary shaft and the electrophotographic photosensitive member of the roller charging member intersect each other at an intersection angle of at least 0.4 degrees.

Images