JP2011028052A - Conductive member, process cartridge having the same, and image forming apparatus having the process cartridge - Google Patents

Abstract

An object of the present invention is to improve the conductivity and impact resistance of a conductive member and to reduce environmental fluctuations in a minute gap between the conductive member and a photosensitive drum, and has excellent durability. A conductive member is provided.
An electrically conductive support, an electric resistance adjustment layer formed on the conductive support, and the electric resistance adjustment layer and an image carrier hold a certain minute gap G. The gap holding member 3 made of a material different from the material of the electrical resistance adjusting layer 4 formed on both ends of the electrical resistance adjusting layer 4 in contact with the image carrier 61 as described above. In member 101, the electric resistance adjusting layer 4 is composed of a resin composition containing an aliphatic polyketone resin (A), a polyetheresteramide resin (B), and an electrolyte salt (C). And
[Selection] Figure 1

Description

  The present invention relates to a conductive member used in an image forming apparatus such as an electrophotographic copying machine, a laser printer, and a facsimile, a process cartridge having the conductive member, and an image forming apparatus having the process cartridge.

  In an electrophotographic image forming apparatus such as a conventional electrophotographic copying machine, laser printer, or facsimile, a charging roller is generally used as a charging member that performs a charging process on an image carrier (photosensitive member). ing. FIG. 6 is a schematic explanatory diagram of a conventional electrophotographic image forming apparatus.

  In FIG. 6, reference numeral 400 denotes a conventional electrophotographic image forming apparatus. A conventional electrophotographic image forming apparatus 400 includes an image carrier 311 on which an electrostatic latent image is formed, a charging roller 312 that performs charging processing in contact with the image carrier 311, an exposure unit 313 such as a laser beam, an image, and the like. The developing roller 314 for attaching toner to the electrostatic latent image on the carrier 311, the transfer roller 316 for transferring the toner image on the image carrier 311 to the recording paper 317, and the image carrier 311 after the transfer processing are cleaned. A cleaning device 318 for the purpose. In FIG. 6, functional units normally required in other electrophotographic processes are omitted because they are not required in this specification.

  Next, a basic image forming operation in charging of the conventional electrophotographic image forming apparatus 400 will be described.

  When a DC voltage is supplied from a power pack (not shown) to the charging roller 312 in contact with the image carrier 311, the surface of the image carrier 311 is uniformly charged at a high potential. Immediately after that, when the image light is irradiated from the exposure means 313 to the surface of the image carrier 311, the potential of the portion of the image carrier 311 irradiated with the image light is lowered. It is known that such a charging mechanism to the surface of the image carrier 311 by the charging roller 312 is a discharge according to Paschen's law in a minute space between the charging roller 312 and the image carrier 311.

  Since the image light has a light amount distribution corresponding to white / black of the image, when the image light is irradiated onto the surface of the image carrier 311, the potential distribution corresponding to the recorded image on the surface of the image carrier 311, that is, An electrostatic latent image is formed. When the portion of the image carrier 311 on which the electrostatic latent image is formed in this way passes through the developing roller 314, toner adheres according to the level of the potential, and a toner image that visualizes the electrostatic image is formed. Is done. The recording paper 317 is conveyed to a portion of the image carrier 311 where the toner image is formed by a registration roller (not shown) at a predetermined timing, and overlaps the toner image. Then, after the toner image is transferred onto the recording paper by the transfer roller 316, the recording paper 317 is separated from the image carrier 311. The separated recording paper 317 is conveyed through a conveyance path, heated and fixed by a fixing unit (not shown), and then discharged outside the apparatus. When the transfer is completed in this manner, the surface of the image carrier 311 is cleaned by the cleaning device 318. Further, residual charges are removed by a quenching lamp (not shown), and the next image forming process is performed. Prepared for.

As a charging method using a charging roller, a contact charging method in which a roller is brought into contact with an image carrier is generally used.
(1) The substance constituting the charging roller oozes out from the charging roller, and this adheres to the surface of the object to be charged and leaves a charging roller mark.
(2) When an AC voltage is applied to the charging roller, the charging roller that is in contact with the member to be charged vibrates, so that a charging noise is generated.
(3) Since the toner on the image carrier adheres to the charging roller (particularly, the above-mentioned oozing out makes toner adhesion more likely), so that the charging performance of the charging roller is reduced.
(4) the substance constituting the charging roller adheres to the image carrier, and
(5) The charging roller is permanently deformed when the image carrier is stopped for a long time.
There was a problem.

  As a technique for solving such a problem, a technique based on a proximity charging system in which a charging roller is brought close to an image carrier (see Patent Documents 1 to 3) has been proposed. In this proximity charging technique, the image bearing member is charged by applying a voltage to the charging roller with the charging roller facing the image bearing member at a closest distance (50 to 300 μm). This is due to the charging method. In this proximity charging technique, since the charging roller and the image carrier are not in contact, there has been a problem in the conventional contact charging technique. (A) The substance constituting the charging roller is an image carrier. The problems of adhering to the body and (b) permanent deformation when the image carrier is stopped for a long time are eliminated. Further, in this proximity charging technique, the amount of toner that adheres to the charging roller is reduced, so that the toner on the image carrier is less likely to adhere to the charging roller, and the charging performance of the charging roller is therefore reduced. There is no.

  The required characteristics of the charging roller used in the proximity charging technique are different from the required characteristics of the charging roller used in the conventional contact charging technique. In the technology using the contact charging method, a charging roller in which an elastic body such as a vulcanized rubber is coated around the core metal has been generally used, and the image carrier is uniformly charged using such a charging roller. In this case, it is necessary to bring the charging roller into uniform contact with the image carrier.

When using a charging roller made of an elastic material such as vulcanized rubber in the proximity charging method,
(1) Since a minute gap is formed between the image carrier and the charging roller, it is necessary to interpose a minute gap holding member such as a spacer in the non-image area at both ends of the charging roller. In the charging roller, since it is difficult to make the minute gap uniform due to deformation of the elastic body, fluctuations in the charging potential and image unevenness due to the fluctuation occur, and
(2) Since the vulcanized rubber material constituting the elastic body is likely to sag and deform over time, the minute gap also varies over time.
There was a problem.

In order to solve such a problem, it is conceivable to use a thermoplastic resin which is an inelastic body. This makes it possible to make the minute gap between the image carrier and the charging roller uniform. The charging mechanism on the surface of the image carrier drum by the charging roller is known to be a discharge according to Paschen's law in the minute discharge between the charging roller and the image carrier drum. In order to obtain the function of maintaining the charged potential, it is necessary to control the electric resistance value of the thermoplastic resin to a semiconductive region (about 10 ⁶ to 10 ⁹ Ωcm).

  As a method of controlling the electrical resistance value, there is a method of dispersing a conductive pigment such as carbon black in a thermoplastic resin. However, when an attempt is made to set the electrical resistance adjustment layer in the semiconductive region using a conductive pigment, since the variation in electrical resistance value increases, partial charging failure occurs, and as a result, image defects occur. There was a problem.

  On the other hand, as another means for controlling the electric resistance value in the electric resistance adjusting layer, there is an electric resistance adjusting layer containing an ion conductive material, that is, an electrolyte salt such as Li salt. Since such ionic conductive materials are dispersed at the molecular level in the matrix resin, there is less variation in resistance compared to the above-mentioned ones in which conductive pigments are dispersed. Is not a problem. However, since electrolyte salts such as Li salts have a low molecular weight, they tend to bleed out on the surface of the matrix resin, which causes toner sticking when the electrolyte salt bleeds out to the surface of the charging roller. As a result, there is a problem that an image defect occurs.

  In order to avoid bleeding out of the electrolyte salt, it is conceivable to use a high molecular weight ion conductive material. In this case, the high molecular weight ion conductive material is dispersed and fixed in the matrix resin. Therefore, bleeding out of the high molecular weight ion conductive material hardly occurs.

  As the polymer type ion conductive material, a polyamide-based elastomer or the like is used. However, since only the polymer type ion conductive material has a high electric resistance value in the electric resistance adjusting layer, The conductive region cannot be controlled. For this reason, the electrical resistance adjusting layer is imparted with conductivity by a resin composition in which a polymer type ion conductive material and an electrolyte salt are combined. Examples of the conductive material include a resin composition in which a polyether ester amide and a perchlorate such as sodium perchlorate and lithium perchlorate are combined, a polyether ester amide and an organic phosphonium salt, and lithium trifluoromethanesulfonate. A resin composition in combination with a fluorine-containing organic anion salt such as is used.

  However, in the charging roller in the image forming apparatus using the proximity charging method, it is necessary to maintain a minute gap between the charging roller and the photosensitive drum, and thus it is necessary that the shape of the charging roller be highly accurate. If the electrical resistance adjustment layer is formed of a resin composition that combines a polymer type ion conductive material and an electrolyte salt, the electrical resistance adjustment layer becomes soft, and the electrical resistance adjustment layer cannot be processed with high accuracy. There was a problem.

  Therefore, in order to solve such problems, a charging member (charging roller) in which an electric resistance adjusting layer is formed of a resin composition containing 30 to 70% by weight of a polycarbonate resin and a polymer type ion conductive material 70 to 30. (See Patent Document 4), but in order to obtain the necessary conductivity for the charging roller in the image forming apparatus using the proximity charging method, the blending ratio of the polymer type ion conductive material in the electric resistance adjusting layer is changed. Must be high. Since the polymer ion conductive material has high hygroscopicity, the volume expansion coefficient (swellability) due to moisture absorption is high. Therefore, when the blending ratio of the polymer type ion conductive material in the electric resistance adjusting layer is increased, the environmental fluctuation of the minute gap between the charging roller and the photosensitive drum is increased. ) Charging performance is greatly affected by the environment. Specifically, in a high-temperature and high-humidity environment, the charging roller expands, so the minute gap between the charging roller and the photosensitive drum decreases, and in an extreme case, the charging roller and the photosensitive drum come into contact with each other. End up. In this case, over time, discharge products and the like on the photosensitive drum adhere to the charging roller side, so that the conductivity in that portion is lowered, and therefore, there is a problem that an image defect occurs. It was. In a low-temperature and low-humidity environment, the minute gap between the charging roller and the photosensitive drum becomes large, so that the discharge from the charging roller to the photosensitive drum becomes non-uniform, which causes a problem of image defects. .

  The present invention aims to solve this problem.

  That is, the present invention can increase the conductivity and impact resistance of the conductive member, and can reduce the environmental fluctuation of the minute gap between the conductive member and the photosensitive drum. It is an object of the present invention to provide an excellent conductive member, a process cartridge having the conductive member, and an image forming apparatus having the process cartridge.

  In order to achieve the above object, the invention described in claim 1 is a conductive support, an electrical resistance adjustment layer formed on the conductive support, the electrical resistance adjustment layer, and an image carrier. A minute gap holding member made of a material different from the material of the electric resistance adjustment layer formed on both ends of the electric resistance adjustment layer in contact with the image carrier so as to hold a certain fine gap; The electrical resistance adjusting layer is composed of a resin composition containing an aliphatic polyketone resin (A), a polyetheresteramide resin (B), and an electrolyte salt (C). It is the electroconductive member characterized by having.

  The invention described in claim 2 is the invention described in claim 1, wherein the ratio of the polyether ester amide resin (B) to the aliphatic polyketone resin (A) in the resin composition: (A) / (B) is 60/40 to 40/60% by weight.

  The invention described in claim 3 is the invention described in claim 1, wherein the electrolyte salt in the resin composition is at least selected from perchlorates, fluorine-containing organic anion salts, and organic phosphonium salts. It is one type of electrolyte salt.

  The invention described in claim 4 is the invention described in claim 1 or 2, wherein a blending ratio of the electrolyte salt (C) to the polyether ester amide resin (B) in the resin composition is 0.00. It is characterized by being 01 to 20% by weight.

  The invention described in claim 5 is the invention described in claim 1, wherein the resin composition further comprises a polycarbonate resin in the main chain and an acrylonitrile-styrene-glycidyl methacrylate copolymer in the side chain. The graft copolymer (D) is contained.

  The invention described in claim 6 is the main chain according to the invention described in claim 2, with respect to the total of the aliphatic polyketone resin (A) and the polyether ester amide resin (B) in the resin composition. The blending ratio of the graft copolymer (D) having a polycarbonate resin in the side chain and an acrylonitrile-styrene-glycidyl methacrylate copolymer in the side chain: (D) / (A) + (B) is 1 to 15% by weight. It is characterized by being.

  The invention described in claim 7 is characterized in that, in the invention described in any one of claims 1 to 6, the resin composition is a resin composition obtained by melt-kneading. Is.

  The invention described in claim 8 is the invention described in any one of claims 1 to 7, wherein the conductive member is provided so as to be disposed close to the image carrier. It is what.

  According to a ninth aspect of the present invention, there is provided a process cartridge in which the conductive member according to the eighth aspect is provided so as to be disposed close to the image carrier.

  According to a tenth aspect of the present invention, there is provided an image forming apparatus including the process cartridge according to the ninth aspect.

  According to the first aspect of the present invention, the conductive support, the electrical resistance adjustment layer formed on the conductive support, and the electrical resistance adjustment layer and the image carrier have a certain minute gap. A conductive member having a minute gap holding member made of a material different from the material of the electric resistance adjusting layer formed on both ends of the electric resistance adjusting layer in contact with the image carrier so as to hold In the above, the electrical resistance adjusting layer is composed of a resin composition containing an aliphatic polyketone resin (A), a polyetheresteramide resin (B), and an electrolyte salt (C). Provided is a highly durable conductive member that can increase the conductivity and impact resistance of the member and can reduce environmental fluctuations in the minute gap between the conductive member and the photosensitive drum. can do.

  According to the invention described in claim 2, the ratio of the polyetheresteramide resin (B) to the aliphatic polyketone resin (A) in the resin composition: (A) / (B) is 60 / 40-40 / 60% by weight, the conductivity and impact resistance of the conductive member can be further increased, and environmental fluctuations in the minute gap between the conductive member and the photosensitive drum can be reduced. It can be made even smaller.

  According to the invention described in claim 3, the electrolyte salt in the resin composition is at least one electrolyte salt selected from perchlorates, fluorine-containing organic anion salts, and organic phosphonium salts. The conductivity can be improved while reducing the hygroscopicity of the electrical resistance adjusting layer.

  According to the invention described in claim 4, since the blending ratio of the electrolyte salt (C) with respect to the polyetheresteramide resin (B) in the resin composition is 0.01 to 20% by weight. The conductivity can be increased while further reducing the hygroscopicity of the electrical resistance adjusting layer.

  According to the invention described in claim 5, the resin composition further contains a graft copolymer (D) having a polycarbonate resin in the main chain and an acrylonitrile-styrene-glycidyl methacrylate copolymer in the side chain. Therefore, the compatibility of the aliphatic polyketone resin (A) and the polyetheresteramide resin (B) is improved, and therefore, impact resistance can be improved without lowering the conductivity. In addition, the processing stability can be improved.

  According to the invention described in claim 6, the main chain has a polycarbonate resin with respect to the total of the aliphatic polyketone resin (A) and the polyether ester amide resin (B) in the resin composition, and the side chain. The blending ratio of the graft copolymer (D) having an acrylonitrile-styrene-glycidyl methacrylate copolymer to (D) / (A) + (B) is 1 to 15% by weight. The compatibility of (A) and the polyether ester amide resin (B) can be further improved. Therefore, the impact resistance can be improved without lowering the conductivity, and the processing stability can be further improved. Can be made.

  According to the invention described in claim 7, since the resin composition is a resin composition obtained by melt-kneading, the aliphatic polyketone resin (A) and the polyether ester amide resin (B) The compatibility can be further improved, and therefore the impact resistance can be improved without lowering the conductivity, and the processing stability can be further improved.

  According to the eighth aspect of the invention, since the conductive member is a charging member provided so as to be disposed close to the image carrier, the surface of the image carrier can be charged in a non-contact manner. For this reason, the charging member can be prevented from being soiled and the like, and the charging member can be made of a hard material, so that the accuracy can be increased. Therefore, uneven charging can be prevented.

  According to the ninth aspect of the present invention, since the conductive member according to the eighth aspect is the process cartridge provided so as to be disposed close to the image carrier, the image quality can be stabilized over a long period of time. In addition, user maintenance is possible and simplified for replacement.

  According to the tenth aspect of the present invention, since the image forming apparatus has the process cartridge according to the ninth aspect, the proximity charging type image capable of obtaining an excellent image quality over a long period of time. It can be a forming device.

It is sectional drawing of the electroconductive member (charging roller) which shows one embodiment of this invention. FIG. 3 is a schematic view showing a state where a conductive member (charging roller) showing an embodiment of the present invention is arranged on an image carrier. It is a schematic explanatory drawing of the process cartridge which has the electroconductive member (charging roller) which shows one embodiment of this invention. 1 is a schematic explanatory diagram of an image forming apparatus (image MP MP6000 manufactured by Ricoh) having a process cartridge according to an embodiment of the present invention. It is a schematic explanatory diagram of a conventional electrophotographic image forming apparatus.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  The present inventors pay attention to the fact that the impact resistance of a polymer alloy of an aliphatic polyketone resin and a polyamide resin is remarkably improved by moisture absorption, and constitutes an electric resistance adjusting layer in a conductive member (charging roller). In the process of examining the resin composition, the resin composition is composed of an aliphatic polyketone resin (A), a polyetheresteramide resin (B), and an electrolyte salt (C). And without impairing the impact resistance, the volume expansion coefficient due to moisture absorption can be lowered, and the environmental fluctuation of the minute gap between the conductive member and the photosensitive drum can be reduced. The present invention has been completed by finding that a conductive member can be provided.

  That is, as shown in FIG. 1, the conductive member (charging roller) 101 of the present invention includes a conductive support 6, an electrical resistance adjusting layer 4 formed on the conductive support 6, The electrical resistance adjustment layer formed on both ends of the electrical resistance adjustment layer 4 in contact with the image carrier 61 so that the electrical resistance adjustment layer 4 and the image carrier 61 maintain a certain minute gap G. 4 and a minute gap holding member 3 made of a material different from the material 4. And the said electrical resistance adjustment layer 4 is comprised with the resin composition containing aliphatic polyketone resin (A), polyetheresteramide resin (B), and electrolyte salt (C). In FIG. 1, 5 is a surface layer, 7 is a bearing, and 8 is a pressure spring (pressure member).

  As described above, the conductive support 6, the electric resistance adjustment layer 4 formed on the conductive support 6, and the electric resistance adjustment layer 4 and the image carrier 61 maintain a certain minute gap G. The gap holding member 3 made of a material different from the material of the electrical resistance adjusting layer 4 formed on both ends of the electrical resistance adjusting layer 4 in contact with the image carrier 61 as described above. In the member 101, the electric resistance adjusting layer 4 is composed of a resin composition containing an aliphatic polyketone resin (A), a polyetheresteramide resin (B), and an electrolyte salt (C). In addition, it is possible to increase the conductivity and impact resistance of the conductive member 101 and to reduce the environmental fluctuation of the minute gap between the conductive member 101 and the photosensitive drum (image carrier) 61. Providing conductive members with excellent durability Rukoto can.

  In the present invention, the ratio of the polyether ester amide resin (B) to the aliphatic polyketone resin (A) in the resin composition: (A) / (B) is preferably 60/40 to 40 / 60% by weight. Thus, the blending ratio of the polyetheresteramide resin (B) to the aliphatic polyketone resin (A) in the resin composition: (A) / (B) is 60/40 to 40/60% by weight. As a result, the conductivity and impact resistance of the conductive member 101 can be further increased, and the environmental fluctuation of the minute gap G between the conductive member 101 and the image carrier 61 can be further reduced. Can do.

  In the present invention, the electrolyte salt in the resin composition is preferably at least one electrolyte salt selected from perchlorates, fluorine-containing organic anion salts, and organic phosphonium salts. Thus, when the electrolyte salt in the resin composition is at least one electrolyte salt selected from perchlorates, fluorine-containing organic anion salts, and organic phosphonium salts, moisture absorption of the electrical resistance adjusting layer The conductivity can be improved while reducing the property.

  In general, when an electron conductive conductive agent such as carbon black is used, the electric charge is discharged to the image carrier through the carbon black, so that minute discharge unevenness due to the dispersion state of the carbon black is likely to occur. Therefore, it becomes difficult to obtain an image with high image quality. In particular, this phenomenon becomes significant when a high voltage is applied. Examples of the ion conductive material include low molecular weight salts such as alkali metal salts and ammonium salts. Since these low molecular weight salts are energized, they easily polarize and bleed out. Therefore, a thermoplastic resin containing an ether group is used as the polymer type ion conductive material. If the polymer constituting the polymer ion conductive material has an ether group, the salt is stabilized by oxygen atoms contained in the ether bond, and a low electric resistance value can be obtained. Since the polymer containing the ether group is uniformly dispersed and fixed at the molecular level in the matrix polymer, there is a variation in resistance value due to poor dispersion as seen in a composition in which a conductive pigment is dispersed. Absent. In addition, since the polymer ion conductive material is a polymer material, bleeding out hardly occurs. Examples of the polymer containing an ether group include polyether ester amide and polyether / polyolefin block polymer. The thermoplastic resin composed of a polymer containing an ether group is generally roughly classified into a grade hydrophilic grade and a hydrophobic grade based on the ratio of the ether group, and the characteristics greatly differ depending on the grade. Therefore, it is possible to blend multiple grades in order to obtain the desired properties.

  However, it is not possible to obtain conductivity for use as the charging member 101 only with the thermoplastic resin material composed of the polymer containing the ether group, but the thermoplastic material composed of the polymer containing the ether group. When the resin material and the electrolyte salt are used in combination, an improvement in conductivity can be achieved. Examples of the electrolyte salt include perchlorates, fluorine-containing organic anion salts, and organic phosphonium salts. The perchlorate can be used as long as it is generally used. However, in consideration of conductivity, the perchlorate is a salt selected from an alkali metal salt and an alkaline earth metal salt. Preferably there is. Among them, the lithium perchlorate and the sodium perchlorate have a high degree of dissociation of their salts and an increased amount of dissociated ions, so that the conductivity is improved. is there. As said fluorine-containing organic anion salt, the salt provided with the anion which has a fluoro group and a sulfonyl group is preferable. The anion-containing salt is high in a polymer composition in which the anion is stable because the charge is delocalized by the strong electron withdrawing effect of the fluoro group (-F) and the sulfonyl group (-SO2-). It shows the degree of dissociation, and therefore high ionic conductivity can be realized.

  Among them, alkali metal salts of bis (fluoroalkylsulfonyl) imide, alkali metal salts of tris (fluoroalkylsulfonyl) methide and alkali metal salts of fluoroalkylsulfonic acid are preferable because it is possible to easily achieve a decrease in electric resistance value. . Specifically, bis (trifluoromethanesulfonyl) imide lithium (Li (CF3SO2) 2N), bis (trifluoromethanesulfonyl) imide potassium (K (CF3SO2) 2N), bis (trifluoromethanesulfonyl) imide sodium (Na (CF3SO2) 2N), tris (trifluoromethanesulfonyl) methidolithium (Li (CF3SO2) 3C), tris (trifluoromethanesulfonyl) methidepotassium (K (CF3SO2) 3C), sodium tris (trifluoromethanesulfonyl) methide (Na (CF3SO2) 3C), Lithium trifluoromethanesulfonate (Li (CF3SO3)), potassium trifluoromethanesulfonate (K (CF3SO3)), sodium trifluoromethanesulfonate (Na ( F3SO3)), and the like. In particular, lithium trifluoromethanesulfonate, lithium bis (trifluoromethanesulfonyl) imide lithium, and lithium salt of tris (trifluoromethanesulfonyl) methide lithium have a very high ion mobility because the ionic radius of the lithium ion that is the cation is small. The conductivity is most improved and is particularly preferable. Examples of the organic phosphonium salts include quaternary phosphonium salts such as ethyltriphenylphosphonium tetrafluoroborate and tetraphenylphosphonium bromide.

  The electrolyte salt can be added to a polymer type ion conductive material and kneaded to be blended in a predetermined ratio, or a plurality of electrolyte salts can be blended and added. As the polyether ester amide containing perchlorate, for example, “IRGASTAT P18” (manufactured by Ciba Specialty Chemicals) is available, and a polymer ion conductive material containing a fluorine-containing organic anion salt For example, “Sanconol” (manufactured by Sanko Chemical Co., Ltd.) is available.

  In the present invention, the blending ratio of the electrolyte salt (C) with respect to the polyetheresteramide resin (B) in the resin composition is preferably 0.01 to 20% by weight. When the blending amount of the electrolyte salt (C) with respect to the polyetheresteramide resin (B) in the resin composition is less than 0.01% by weight, the conductivity is insufficient, and when it exceeds 20% by weight. It becomes difficult to disperse uniformly in the resin composition. Therefore, when the blending ratio of the electrolyte salt (C) to the polyether ester amide resin (B) in the resin composition is 0.01 to 20% by weight, the hygroscopicity of the electric resistance adjusting layer is further increased. The conductivity can be increased while decreasing.

The volume resistivity of the electric resistance adjusting layer 4 is preferably 10 ⁶ to 10 ⁹ Ωcm. When the volume resistivity of the electric resistance adjusting layer exceeds 10 ⁹ Ωcm, charging ability and transfer ability are insufficient, and when it is less than 10 ⁶ Ωcm, leakage due to voltage concentration on the entire photoreceptor occurs. End up. About the compounding quantity of the said electrolyte salt (C), if it is a range which does not impair the electroconductivity of the said electrical resistance adjustment layer 4, according to the target machinability within the range of the compounding rate of the said electrolyte salt (C). Can be set.

で示されるエチレン−プロピレン−一酸化炭素共重合体であって、一酸化炭素から誘導される単位とオレフィンから誘導される単位とが交互に配列されている交互共重合体ユニットを含むものである。共重合比率としては、ｙ／ｘ＝０．０５〜０．１０が特に好ましく、この範囲では、機械特性、衝撃強度が一層良好となる。ポリケトン樹脂の分子量に特に制限は無いが、標準細管粘度測定で測定したポリマーの極限粘度（ＬＶＮ）で、ｍ−クレゾール中、６０℃で１．０〜２．０程度のものが、成形性と耐衝撃性が良好で好ましい。 The aliphatic polyketone resin has the following formula:

And an alternating copolymer unit in which units derived from carbon monoxide and units derived from olefin are alternately arranged. The copolymerization ratio is particularly preferably y / x = 0.05 to 0.10, and mechanical properties and impact strength are further improved in this range. The molecular weight of the polyketone resin is not particularly limited, but the intrinsic viscosity (LVN) of the polymer measured by standard capillary viscosity measurement is about 1.0 to 2.0 at 60 ° C. in m-cresol. Good impact resistance is preferable.

  As a method for producing the aliphatic polyketone resin, a known polymerization method can be employed. For example, a hydrohalic acid having a pKa of 6 or less measured in an aqueous solution of carbon monoxide and olefin in a palladium compound and 18 ° C. Non-acidic and phosphorous bidentate ligand compounds may be used in the presence of a catalyst compound. It can also be obtained as “Carillon” (manufactured by Shells Chemicals).

  In the present invention, the resin composition containing the aliphatic polyketone resin (A), the polyether ester amide resin (B), and the electrolyte salt (C) preferably has a polycarbonate resin in the main chain. A graft copolymer (D) having an acrylonitrile-styrene-glycidyl methacrylate copolymer in the side chain is contained. Thus, when the resin composition further contains a graft copolymer (D) having a polycarbonate resin in the main chain and an acrylonitrile-styrene-glycidyl methacrylate copolymer in the side chain, the aliphatic polyketone Improving the compatibility of the resin (A) and the polyether ester amide resin (B), thereby improving the impact resistance without lowering the electrical conductivity and improving the processing stability. be able to.

  The main chain polycarbonate resin in the graft copolymer (D) having a polycarbonate resin in the main chain and an acrylonitrile-styrene-glycidyl methacrylate copolymer in the side chain has a molecular structure having a chain of a polar group and a dioxy group. Therefore, the attractive force between molecules is very strong. The acrylonitrile-styrene-glycidyl methacrylate copolymer contained in the side chain is composed of an acrylonitrile component and a glycidyl methacrylate component that is a reactive group with the styrene component. In the glycidyl methacrylate of the reactive group, the epoxy group reacts with the ester group or amide group of the resin (B) by heating when the components are melted and kneaded to form a strong chemical bond. The graft copolymer (D) having a polycarbonate resin in the main chain and an acrylonitrile-styrene-glycidyl methacrylate copolymer in the side chain is a phase between the resin (A) and the resin (B) which originally have low affinity. Since it functions as a solubilizer and the dispersed state of the resin (A) and the resin (B) is uniform and densified, it is possible to obtain higher impact resistance.

  It has a polycarbonate resin in the main chain and an acrylonitrile-styrene-glycidyl methacrylate copolymer in the side chain with respect to the total of the aliphatic polyketone resin (A) and the polyether ester amide resin (B) in the resin composition. The blending ratio of the graft copolymer (D): (D) / (A) + (B) is 1 to 15% by weight. Thus, the total of the aliphatic polyketone resin (A) and the polyetheresteramide resin (B) in the resin composition has a polycarbonate resin in the main chain and an acrylonitrile-styrene-glycidyl methacrylate copolymer in the side chain. When the blending ratio of the graft copolymer (D) having a polymer: (D) / (A) + (B) is 1 to 15% by weight, the aliphatic polyketone resin (A) and the polyether ester The compatibility of the amide resin (B) can be further improved. Therefore, the impact resistance can be improved without lowering the conductivity, and the processing stability can be further improved.

  In the present invention, the resin composition is a resin composition obtained by melt-kneading. Thus, when the resin composition is a resin composition obtained by melt-kneading, the compatibility of the aliphatic polyketone resin (A) and the polyether ester amide resin (B) is further improved. In addition, the impact resistance can be improved without lowering the electrical conductivity, and the processing stability can be further improved.

  Although there is no restriction | limiting in particular regarding the manufacturing method of the said resin composition, It can manufacture easily by melt-kneading the mixture of each material with a biaxial kneader, a kneader, etc. The electric resistance adjusting layer 4 is easily formed on the conductive support by covering the conductive support 6 with the semiconductive resin composition by a molding means such as extrusion molding or injection molding. be able to.

If only the electric resistance adjusting layer 4 is formed on the conductive support 6 to form the conductive member 101, toner, toner additive, etc. may adhere to the electric resistance adjusting layer and the performance may deteriorate. Such a problem can be prevented by forming the surface layer 5 on the electric resistance adjusting layer 4. The electric resistance value of the surface layer 5 is formed so as to be larger than that of the electric resistance adjusting layer 4, thereby avoiding voltage concentration and abnormal discharge (leakage) on the photosensitive member defect portion. However, if the electric resistance value of the surface layer 5 is too high, the charging ability and the transfer ability are insufficient, so that the difference in electric resistance value between the surface layer 5 and the electric resistance adjusting layer 4 is 10 ³ Ωcm or less. It is preferable to do. As a material for forming the surface layer 5, fluorine resin, silicone resin, polyamide resin, polyester resin and the like are excellent in non-adhesiveness and are preferable in terms of preventing toner sticking.

  The surface layer 5 is formed on the electric resistance adjusting layer 4 by preparing the paint by dissolving the constituent material of the surface layer 5 in an organic solvent, and various coatings such as spray coating, dipping, roll coating, etc. By the way. About a film thickness, about 10-30 micrometers is preferable. The material constituting the surface layer 5 can be either one-component or two-component, but it is environmentally resistant, non-adhesive, and releasable by making it a two-component paint that uses a curing agent in combination. Can be increased. In the case of a two-component paint, a method of crosslinking and curing the resin by heating the coating film is common. However, since the electrical resistance adjusting layer 4 is made of a thermoplastic resin, it cannot be heated at a high temperature. As the two-component paint, it is effective to use a main component having a hydroxyl group in the molecule and an isocyanate resin that causes a crosslinking reaction with the hydroxyl group. By using an isocyanate resin, a crosslinking / curing reaction occurs at a relatively low temperature of 100 ° C. or lower. As a result of investigations from the non-adhesiveness of the toner, it was confirmed that the resin is a silicone-based resin having a high non-adhesiveness of the toner, and an acrylic silicone resin having an acrylic skeleton in the molecule is particularly good.

  Since the electrical characteristics (electrical resistance value) of the conductive member 101 are important, it is necessary to make the surface layer 5 conductive. In order to make the surface layer 5 conductive, a conductive agent is dispersed in the resin material constituting the surface layer 5. The conductivity-imparting agent is not particularly limited, but for example, conductive carbon such as ketjen black EC and acetylene black, and rubbers such as SAF, ISAF, HAF, FEF, GPF, SRF, FT, and MT. Carbon, carbon for color with oxidation treatment, pyrolytic carbon, indium-doped tin oxide (ITO), tin oxide, titanium oxide, zinc oxide, copper, silver, germanium and other metals, and metal oxides, polyaniline, Examples thereof include conductive polymers such as polypyrrole and polyacetylene. In addition, there are ionic conductive materials as conductivity imparting materials, inorganic ionic conductive materials such as sodium perchlorate, lithium perchlorate, calcium perchlorate, lithium chloride, and further ethyltriphenylphosphonium tetrafluoroborate And organic ionic conductive substances such as quaternary phosphonium salts such as tetraphenylphosphonium bromide, modified fatty acid dimethylammonium ethosulphate, ammonium stearate acetate, and laurylammonium acetate.

  As shown in FIG. 1, the conductive member 101 is a charging member provided so as to be disposed close to the image carrier 61. As described above, the charging member provided so that the conductive member 101 is disposed close to the image carrier 61 and the surface of the image carrier 61 can be charged in a non-contact manner. In addition, the charging member can be made of a hard material, so that the accuracy can be improved. Therefore, uneven charging can be prevented.

  As shown in FIG. 2, the charging device 100 is opposite to the image carrier 61 and is provided with a conductive member (charging member) 101 provided with a minute gap (see G in FIG. 1). A cleaning member 102 that cleans the charging member, a power source (not shown) that applies a voltage to the charging member 101, and a pressure spring (not shown) that presses and contacts the charging member 101 to the image carrier 61. And at least.

  As shown in FIG. 1, the conductive member (charging member) 101 is disposed facing the image carrier 61 with a minute gap G therebetween. The minute gap G between the charging member 101 and the image carrier 61 is formed by bringing the gap holding member 103 into contact with the non-image forming area of the charging member 101. By bringing the gap holding member 3 into contact with the photosensitive layer region of the image carrier 61, even if the coating thickness of the photosensitive layer varies, it is possible to prevent the variation in the minute gap G. In the charging member 101, the gap holding member 3 is disposed on both ends of the electric resistance adjusting layer 4 formed on the conductive support 6. Further, a surface layer 5 is formed on the surface of the electric resistance adjusting layer 4 so that the toner and the toner additive are difficult to adhere. The shape of the charging member 1 is not particularly limited. For example, the charging member 1 may be fixed in a belt shape, a blade (plate) shape, or a semi-cylindrical shape.

  The charging member 101 may have a cylindrical shape, and both ends may be rotatably supported by gears or bearings. As described above, when the charging member 1 is formed with a curved surface that gradually separates from the closest part to the image carrier 61 in the moving direction of the image carrier 61, the image carrier 61 is made more uniform. Can be charged. If there is a sharp portion on the charging member 1 facing the image carrier 61, the potential at that portion becomes high, so that discharge is preferentially started, and therefore it is difficult to uniformly charge the image carrier 61. . Therefore, when the charging member 1 has a cylindrical shape and has a curved surface, the image carrier 61 can be uniformly charged. Further, the discharging surface of the charging member 1 is subjected to strong stress. Since the discharge always occurs on the same surface, its deterioration is promoted and may be scraped off. Therefore, if the entire surface of the charging member 1 can be used as a discharging surface, the charging member 1 can be rotated to prevent early deterioration of the charging member 1 and used for a long period of time. it can.

  The minute gap G between the charging member 1 and the image carrier 61 is preferably set to 100 μm or less, more preferably in the range of about 5 to 70 μm, by the gap holding member 3. Thereby, formation of an abnormal image at the time of operation of charging device 100 can be suppressed. When the minute gap G is 100 μm or more, the distance to reach the image carrier 61 becomes longer, so the discharge start voltage according to Paschen's law increases. Further, since the discharge space to the image carrier 61 becomes large, in order to charge the image carrier 61 to a predetermined charge, a large amount of discharge products are required due to the discharge. For this reason, the discharge products remain after the image formation. A large amount remains in the discharge space, adheres to the image carrier 61, and causes deterioration of the image carrier 61 over time. Further, when the minute gap G is small, the reach distance to the image carrier 61 is shortened, so that the image carrier 61 can be charged even if the discharge energy is small. However, since the space formed by the charging member 1 and the image carrier 61 is narrowed and the air flow is deteriorated, the discharge product formed in the discharge space stays in this space. As in the case where the minute gap G is large, a large amount of discharge products remain in the discharge space after image formation and adhere to the image carrier 61, which causes deterioration of the image carrier 61 over time. Therefore, it is preferable to reduce the discharge energy to reduce the generation of discharge products and to form a space that does not retain air. From such a viewpoint, the minute gap G is preferably 100 μm or less, and more preferably 5 to 70 μm. Thus, when the minute gap G is set to 100 μm or less, the generation of streamer discharge is prevented, the generation of discharge products is reduced, the amount deposited on the image carrier 61 is reduced, and the spot-like image spots / Image flow can be prevented.

  The toner remaining on the image carrier 61 after development is cleaned by a cleaning device 64 provided opposite to the image carrier 61, but it is difficult to completely remove the toner, and a very small amount of toner passes through the cleaning device. Passes and is conveyed to the charging device 100. At this time, if the particle diameter of the toner is larger than the minute gap G, the toner may be rubbed by the rotating image carrier 61 or the charging member 101 to be heated and fused to the charging member 101. The portion where the toner is fused is close to the image carrier 61 and thus causes abnormal discharge that preferentially causes discharge. Therefore, the minute gap G is preferably larger than the maximum particle diameter of the toner used in the image forming apparatus 300.

  As shown in FIGS. 1 and 2, the charging member 1 is fitted to a bearing 7 provided on a side plate of a housing (not shown) of the charging device 100, and the bearing 7 is made of a resin having a low friction coefficient and not driven by the bearing 7. The compression spring 8 is pressed against the surface of the image carrier 61. Thereby, a certain minute gap G can be formed even if there is mechanical vibration and displacement of the conductive support (core metal) 6. The pressing load is preferably 4 to 25N, and more preferably 6 to 15N. Even if the charging member 1 is fixed by the bearing 7, the size of the minute gap G varies due to vibration when rotating, eccentricity of the charging member, and irregularities on the surface thereof. For this reason, the deterioration of the image carrier 61 is promoted over time. Here, the load means all loads applied to the image carrier 61 through the gap holding member 103. The load can be adjusted by the force of the compression springs 108 provided at both ends of the charging member 101, the weight of the charging member 101 and the cleaning member 102, and the like. When the load is small, fluctuation due to rotation of the charging member 101 and jumping up due to impact force of a driving gear or the like cannot be suppressed. When the load is large, the friction between the charging member 101 and the bearing 107 to be fitted increases, and the amount of wear over time is increased to promote fluctuation. Therefore, the load is preferably in the range of 4 to 25 N, more preferably in the range of 6 to 15 N, and the minute gap G is set to an appropriate range, so that the generation of discharge products is reduced and the image carrier 61 can be reduced. The amount deposited can be reduced. Therefore, the life of the image carrier 61 can be extended, and spotted abnormal images / image flows can be prevented.

  A part of the gap holding member 3 has a difference in height from the electric resistance adjusting layer 4. As a method of forming the minute gap G, the electrical resistance adjusting layer 4 and the gap holding member 3 can be formed by performing removal processing such as cutting and grinding and simultaneously processing. When the gap holding member 3 and the electrical resistance adjusting layer 4 are processed simultaneously, the minute gap G can be formed with high accuracy. If the height of the portion of the gap holding member 3 adjacent to the electric resistance adjusting layer 4 is the same as or lower than the height of the electric resistance adjusting layer 4, the contact width between the gap holding member 3 and the image carrier 61 is reduced. Therefore, the minute gap G between the conductive member (charging member) 101 and the image carrier 61 can be made highly accurate. In this way, it is possible to prevent the outer surface of the side end portion of the electrical resistance adjusting layer 4 of the gap holding member 3 from coming into contact with the image carrier 61. It can be prevented that the layer 4 comes into contact with the image carrier 61 and a leak current is generated. Moreover, the edge part by the side of the electrical resistance adjustment layer 4 of the gap | interval holding | maintenance part 3 can be processed low, and this part can be made into relief allowances (escape process), such as a cutting blade at the time of removal processing. The shape of the clearance allowance (relief processing) may be any shape as long as the outer surface of the end portion of the gap holding portion 3 is not in contact with the image carrier 61.

  Further, it is difficult to perform masking at the boundary between the electric resistance adjusting layer 4 and the gap holding member 3 when coating the surface layer 5 in consideration of variations. Therefore, when forming a step, the electric resistance adjusting layer 4 is formed. If the surface layer 5 is formed up to the gap holding portion 3 that is the same as or lower than that, the surface layer 5 can be reliably formed on the electric resistance adjusting layer 4. A necessary characteristic of the gap holding member 3 is that the minute gap G between the image holding body 61 and the image carrier 61 is stably formed over the environment and for a long time (time). The material to be used is preferably a material having low hygroscopicity and wear resistance. Further, since the gap holding member 3 slides in contact with the image carrier 61, the material constituting the gap holding member 3 is such that the toner and the toner additive are less likely to adhere to the image carrier 61, It is important that the image carrier 61 is not worn. Therefore, the material constituting the gap holding member 3 is appropriately selected according to various conditions.

Specifically, the material constituting the gap retaining member 3 is polyethylene (PE), polypropylene (PP), polyacetal (POM), polymethyl methacrylate (PMMA), polystyrene (PS) and a copolymer (AS). , ABS) and the like, polycarbonate (PC), urethane, fluorine (PTFE) and the like. In order to securely fix the gap holding member 3, an adhesive may be applied and bonded. The gap holding member 3 is preferably made of an insulating material, and its volume resistivity is preferably 10 ¹³ Ωcm or more. The reason why electrical insulation is necessary is to eliminate the occurrence of leakage current with the image carrier 61. The gap holding member 3 is formed by a molding process.

  As shown in FIG. 2, the conductive member (charging member) 101 of the present invention is preferably a process cartridge 200 provided so as to be disposed close to the image carrier 61. Thus, when the process cartridge 200 is provided so that the conductive member 101 is disposed close to the image carrier 61, stable image quality can be obtained over a long period of time, and replacement can be performed by the user. Maintenance is possible and simplified.

  In the process cartridge 200, the surface of the image carrier 61 is uniformly charged by a charging member in which an image forming area is arranged in a non-contact manner, and is visualized by development after an image (latent image) is formed. Transferred to a recording medium. The toner remaining on the image carrier 61 without being transferred to the recording medium is collected by the auxiliary cleaning member 64d. In order to prevent toner and toner constituent materials from adhering to the surface of the image carrier 61, a solid lubricant 64a is uniformly applied on the image carrier 61 by the application member 64b to form a lubricant layer. . The toner that could not be collected by the auxiliary cleaning member 64d by the cleaning member 64c is collected and conveyed to the waste toner collecting unit. The auxiliary cleaning member 64d includes a roller shape and a brush shape, and the solid lubricant reduces the friction coefficient on the image carrier such as fatty acid metal salts such as zinc stearate and polytetrafluoroethylene. That can impart non-tackiness. Examples of the cleaning device 64 include a blade made of rubber such as silicon and urethane, and a fur brush made of fiber such as polyester.

  The charging device 100 includes a cleaning member 102 for removing contamination of the conductive member (charging member) 101. The shape of the cleaning member 102 may be a roller shape or a pad shape, but in the present invention, it is a roller shape. The cleaning member 102 is fitted into a bearing provided in a housing (not shown) of the charging device 100 and is rotatably supported. The cleaning member 102 contacts the charging member 101 and cleans the outer peripheral surface. If foreign matter such as toner, paper dust, or a damaged member adheres to the surface of the charging member 101, abnormal electric discharge that preferentially generates discharge occurs because the electric field concentrates on the foreign matter portion. On the contrary, when an electrically insulating foreign material adheres to a wide range, since no discharge occurs in that portion, charging spots are generated on the image carrier 61. Therefore, the surface of the charging member 101 is cleaned in the charging device 100. A cleaning member 102 is preferably provided. As the cleaning member 102, a brush such as a polyester fiber or a porous material (sponge) such as a melamine resin can be used. The cleaning member 102 may be rotated with the charging member 101, rotated with a linear velocity difference, and separated and intermittently rotated. The charging device 100 includes a power source that applies a voltage to the charging member 101.

  The voltage may be only a DC voltage, but a voltage obtained by superimposing a DC voltage and an AC voltage is preferable. When there is a portion where the layer configuration of the charging member 101 is non-uniform, the surface potential of the image carrier 61 may become non-uniform when only a DC voltage is applied. With the superimposed voltage, the surface of the charging member 101 becomes equipotential, so that the discharge is stable and the image carrier 61 can be charged uniformly. The alternating voltage in the superimposed voltage preferably has a peak-to-peak voltage that is at least twice the charging start voltage of the image carrier 61. The charging start voltage is an absolute value of a voltage when the image carrier 61 starts to be charged when only a direct current is applied to the charging member 101. Accordingly, reverse discharge from the image carrier 61 to the charging member 101 occurs, and the leveling effect enables the image carrier 61 to be uniformly charged in a more stable state. The frequency of the AC voltage is preferably 7 times or more the peripheral speed (process speed) of the image carrier 61. By setting the frequency to 7 times or more, the moire image cannot be recognized (visually).

  As shown in FIG. 2, in the present invention, the auxiliary cleaning member 64d is a brush roller, and the lubricant is formed of zinc stearate in a block shape. By applying pressure, the solid lubricant scraped off from the solid lubricant block 64a by the application roller 64b is applied to the image carrier 61. The cleaning member 64d is a counter type using a urethane blade. Further, the cleaning member 64c of the charging member 101 can be cleaned well with the surface of the charging member 101 by using a melamine resin sponge roller and rotating together with the charging member 101. In FIG. 2, 64 is a cleaning device.

  As shown in FIGS. 3 and 4, an image forming apparatus 300 of the present invention has the process cartridge according to the ninth aspect. Thus, with the image forming apparatus 300 having the process cartridge according to the ninth aspect, it is possible to obtain an image with high reliability and high image quality.

  The image forming apparatus 300 of the present invention has a drum shape having a photosensitive layer on the surface, and corresponds to the number corresponding to four colors of yellow (Y), magenta (M), cyan (C), and black (K). An image carrier 61, a charging device 100 for charging each image carrier 61 almost uniformly, an exposure device 70 for exposing the charged image carrier 61 with a laser beam to form an electrostatic latent image, A developing device 63 that contains developer of four colors, yellow, magenta, cyan, and black, forms a toner image corresponding to the electrostatic latent image on the image carrier 61, and transfers the toner image on the image carrier 61 A primary transfer device 62, a belt-like intermediate transfer member 50 to which a toner image on the image carrier 61 is transferred, a secondary transfer device 51 for transferring the toner image of the intermediate transfer member 50, and the intermediate transfer member 50. The toner image on the recording medium to which the toner image is transferred is fixed. A fixing device 80, further includes a cleaning device 64 for removing the toner remaining after transfer on the image carrier 61. The recording medium is conveyed from one of the paper feeding devices 21 and 22 that store the recording medium one by one to the registration roller 23 through the conveyance path by the conveyance roller. Here, the recording medium is synchronized with the toner image on the image carrier 61. Measured and transferred to the transfer position.

  As shown in FIGS. 3 and 4, the exposure device 70 in the image forming apparatus 300 irradiates the image carrier 61 charged by the charging device 100 with light, and electrostatically charges the image carrier 61 having photoconductivity. A latent image is formed. The light L may be a lamp such as a fluorescent lamp or a halogen lamp, or a laser beam by a semiconductor element such as an LED or LD. Here, an LD element is used when irradiation is performed in synchronization with the rotation speed of the image carrier 61 by a signal from an image processing unit (not shown). The developing device 63 has a developer carrying member, and the toner stored in the developing device 63 is conveyed to a stirring unit by a supply roller, mixed and stirred with a developer containing a carrier, and faces the image carrying member 61. To the developing area. At this time, the positively or negatively charged toner is transferred to the electrostatic latent image on the image carrier 61 and developed. The developer may be a magnetic or non-magnetic one-component developer or a combination thereof, or a wet developer.

  The primary transfer device 62 transfers the developed toner image on the image carrier 61 to the intermediate transfer member 50 by forming an electric field having a polarity opposite to the polarity of the toner from the back side of the intermediate transfer member 50. The primary transfer device 62 may be any one of a corotron, a scorotron corona transfer device, a transfer roller, and a transfer brush. Thereafter, the toner image is transferred onto the recording medium again by the transfer by the secondary transfer device 51 in synchronization with the recording medium conveyed from the paper feeding device 22. Here, the first transfer may be performed directly on the recording medium instead of the intermediate transfer member 50.

  The fixing device 80 heats and / or pressurizes the toner image on the recording medium to fix and fix the toner image on the recording medium. Here, the toner is passed through a pair of pressure and fixing rollers, and heat and pressure are applied at this time to fix the toner while melting the binder resin. The fixing device 80 may be in the form of a belt instead of a roller, or may be fixed by heat irradiation with a halogen lamp or the like. The cleaning device 64 for the image carrier 61 cleans and removes the toner remaining on the image carrier 61 without being transferred, thereby enabling the next image formation. The cleaning device 64 may be any system such as a blade made of rubber such as urethane or a fur brush made of fiber such as polyester.

  Hereinafter, the operation of the image forming apparatus 300 of the present invention will be described. The reading unit 30 sets a document on the document table of the document transport unit 36, or opens the document transport unit 36 to set a document on the contact glass 31, closes the document transport unit 36, and presses the document. When a start switch (not shown) is pressed, the original is conveyed onto the contact glass 31 when the original is set on the original conveying section 36, and immediately after the original is set on the other contact glass 31, the first The first reading traveling body and the second reading traveling body 32, 33 travel. Then, light is emitted from the light source by the first reading traveling body 32 and reflected light from the document surface is further reflected toward the second reading traveling body 33 and reflected by the mirror of the second reading traveling body 33 to form an image. The image information is read through the lens 34 into the CCD 35 which is a reading sensor. The read image information is sent to this control unit. Based on the image information received from the reading unit 30, the control unit controls an LD (not shown) or an LED (not shown) disposed in the exposure device 70 of the image forming unit 60, and writes the laser toward the image carrier 61. Light L is irradiated. By this irradiation, an electrostatic latent image is formed on the surface of the image carrier 61.

  The paper feeding unit 20 feeds a recording medium from a multi-stage paper feeding cassette 21 by a paper feeding roller, separates the fed recording medium by a separation roller, sends it to a paper feeding path, and records it on the paper feeding path of the image forming unit 60. The medium is transported by a transport roller. In addition to the paper feeding unit 20, manual paper feeding is also possible, and a manual feed tray for manual feeding and a separation roller for separating the recording medium on the manual tray one by one toward the manual paper feed path are also provided on the side of the apparatus. I have. Each of the registration rollers 23 discharges only one recording medium placed on the paper feed cassette 21 and sends it to a secondary transfer unit positioned between the intermediate transfer member 50 and the secondary transfer device 51. When the image forming unit 60 receives image information from the reading unit 30, the image forming unit 60 forms a latent image on the image carrier 61 by performing the laser writing or the development process as described above.

  The developer in the developing device 63 is drawn up and held by a magnetic pole (not shown) to form a magnetic brush on the developer carrier. Further, the toner image is transferred to the image carrier 61 by a developing bias voltage applied to the developer carrier, and the electrostatic latent image on the image carrier 61 is visualized to form a toner image. As the developing bias voltage, an AC voltage and a DC voltage are superimposed. Next, one of the paper feed rollers of the paper feed unit 20 is operated to feed a recording medium having a size corresponding to the toner image. Along with this, one of the support rollers is rotationally driven by the drive motor, the other two support rollers are driven to rotate, and the intermediate transfer member 50 is rotated and conveyed. At the same time, the image carrier 61 is rotated by each image forming unit to form black, yellow, magenta, and cyan monochrome images on the image carrier 61, respectively. Then, as the intermediate transfer member 50 is transported, the monochrome images are sequentially transferred to form a composite toner image on the intermediate transfer member 50.

  On the other hand, one of the paper feed rollers of the paper feed unit 20 is selectively rotated, the recording medium is fed out from one of the paper feed cassettes 21, separated one by one by the separation roller, and put into the paper feed path, and the image is taken by the transport roller The recording medium is guided to the sheet feeding path in the image forming unit 60 of the forming apparatus 1 and the recording medium is abutted against the registration roller 23 and stopped. Then, the registration roller 23 is rotated in synchronization with the synthetic toner image on the intermediate transfer member 50, and the recording medium is sent to the secondary transfer portion which is a contact portion between the intermediate transfer member 50 and the secondary transfer device 51. The toner image is secondarily transferred by the influence of the secondary transfer bias and contact pressure formed in the secondary transfer portion, and the toner image is recorded on the recording medium. Here, the secondary transfer bias is preferably a direct current. The recording medium after the image transfer is sent to the fixing device 80 by the transport belt of the secondary transfer device, and the fixing device 80 fixes the toner image by applying pressure and heat by the pressure roller, and then the discharging roller 41. The paper is discharged onto the paper discharge tray 40.

  In the present embodiment, the description has been mainly made of the charging roller in which the conductive member 101 is embodied. However, the conductive member 101 in the present invention may be used as a toner carrier or a transfer member as long as it does not contradict the purpose of the present invention. Absent.

Example 1
Contact between carbon monoxide, ethylene and propylene in methanol with palladium acetate, trifluoroacetic acid and 1,3-bis [bis (2-methoxyphenyl) phosphino] propane to make aliphatic of the linear alternating copolymer A polyketone resin was produced. The melting point of this aliphatic polyketone resin was 220 ° C., and the LVN was 1.78 dl / g (measured in m-cresol at 60 ° C.). Various stabilizers were blended in the aliphatic polyketone resin, mixed with a mixer, and pelletized using a twin-screw extruder to obtain an aliphatic polyketone resin pellet. And 40 parts by weight of the aliphatic polyketone resin (A), polyetheresteramide resin (IRGASTAT P18, manufactured by Ciba Specialty Chemicals) containing sodium perchlorate (C) (B) 60 parts by weight, and polycarbonate- A resin composition composed of 4.5 parts by weight (D) of a glycidyl methacrylate-styrene-acrylonitrile copolymer (Modiper C L440-G, manufactured by NOF Corporation) is melt-kneaded at 220 ° C., and is made of stainless steel. A core shaft having an outer diameter of 10 mm was coated by injection molding to form an electric resistance adjusting layer to obtain a roller. Next, a ring-shaped gap holding member made of high-density polyethylene resin (Novatech HD HY540, manufactured by Nippon Polyethylene) is inserted into both ends of the roller, and the gap holding member, the core shaft and the electric resistance adjusting layer are After the bonding, the gap holding member and the electric resistance adjusting layer are cut so that the outer diameter (maximum diameter) of the gap holding member is 12.80 mm and the outer diameter of the electric resistance adjusting layer is 12 70 mm. Subsequently, a coating composition comprising an acrylic silicon resin (3000 VH-P, manufactured by Kawakami Paint Co., Ltd.), an isocyanate curing agent, and carbon black (35% by weight based on the total solid content) on the surface of the electric resistance adjusting layer. A conductive member (charging roller) was obtained by applying a material and firing to form a surface layer having a thickness of 10 μm.

(Example 2)
60 parts by weight of the aliphatic polyketone resin (A) produced in Example 1, polyether ester amide resin (TPAE-H151, manufactured by Fuji Kasei Kogyo Co., Ltd.) (B), 40 parts by weight of bis (trifluoromethanesulfonyl) imide lithium ( From 2 parts by weight of Li (CF3SO2) 2N, manufactured by Morita Chemical Co., Ltd.) (C) and 3 parts by weight of polycarbonate-glycidyl methacrylate-styrene-acrylonitrile copolymer (Modiper C L440-G, manufactured by NOF Corporation) (D) Example 1 except that the resin composition thus formed was melt-kneaded at 220 ° C., and this was coated by injection molding on a core shaft made of stainless steel having an outer diameter of 10 mm to form an electric resistance adjusting layer to form a roller. Similarly, a charging roller was obtained.

(Example 3)
40 parts by weight of the aliphatic polyketone resin (A) produced in Example 1 above, polyetheresteramide resin (TPAE-H151, manufactured by Fuji Kasei Kogyo Co., Ltd.) (B) 60 parts by weight, organic phosphonium salt (ETPP-FB, Japan) (Chemical Industry Co., Ltd.) (C) 2 parts by weight and polycarbonate-glycidyl methacrylate-styrene-acrylonitrile copolymer (Modiper CL440-G, manufactured by NOF Corporation) (D) 1.5 parts by weight of resin composition The charging roller was the same as in Example 1 except that the product was melted and kneaded at 220 ° C., and this was coated by injection molding on a core shaft made of stainless steel having an outer diameter of 10 mm to form an electric resistance adjusting layer. Got.

Example 4
Aliphatic polyketone resin (D26HM100, manufactured by Shells Chemicals) (A) 40 parts by weight, polyetheresteramide resin (TBX-65, manufactured by Sanko Chemical Co., Ltd.) containing lithium trifluoromethanesulfonate (C) (B) 60 A resin composition composed of 6 parts by weight of a polycarbonate-glycidyl methacrylate-styrene-acrylonitrile copolymer (Modiper C L440-G, manufactured by NOF Corporation) (D) is melt-kneaded at 220 ° C. A charging roller was obtained in the same manner as in Example 1, except that a core shaft made of stainless steel having an outer diameter of 10 mm was coated by injection molding to form an electric resistance adjusting layer.

(Example 5)
Aliphatic polyketone resin (D26HM100, manufactured by Shells Chemicals) (A) 50 parts by weight, polyetheresteramide resin (IRGASTAT P18, manufactured by Ciba Specialty Chemicals) containing sodium perchlorate (C) (B) 50 weights And a resin composition composed of 4.5 parts by weight of a polycarbonate-glycidyl methacrylate-styrene-acrylonitrile copolymer (Modiper CL 440-G, manufactured by NOF Corporation) (D). A charging roller was obtained in the same manner as in Example 1 except that a core shaft made of stainless steel having an outer diameter of 10 mm was coated by injection molding to form an electric resistance adjusting layer to obtain a roller.

(Comparative Example 1)
ABS resin (DENKA ABS GR-3000, manufactured by Denki Kagaku Kogyo Co., Ltd.) 40 parts by weight, polyether ester amide resin containing sodium perchlorate (C) (IRGASTAT P18, manufactured by Ciba Specialty Chemicals Co., Ltd.) (B) 60 wt. And a resin composition composed of 4.5 parts by weight of a polycarbonate-glycidyl methacrylate-styrene-acrylonitrile copolymer (Modiper C L440-G, manufactured by NOF Corporation) (D), a core having an outer diameter of 10 mm made of stainless steel A charging roller was obtained in the same manner as in Example 1 except that the roller was formed by coating the shaft at 220 ° C. by injection molding to form an electric resistance adjusting layer.

(Comparative Example 2)
A resin composition comprising 60 parts by weight of a polyketone resin (D26HM100, manufactured by Shells Chemicals) (A) and 40 parts by weight of a polyether ester amide resin (TPAE-10HP, manufactured by Fuji Kasei Kogyo Co., Ltd.) (B) is stainless steel. A charging roller was obtained in the same manner as in Example 1 except that a roller having an electric resistance adjusting layer was formed by coating a core shaft having an outer diameter of 10 mm at 220 ° C. by injection molding.

(Comparative Example 3)
20 parts by weight of polycarbonate resin (Iupilon H-4000, manufactured by Mitsubishi Engineering Plastics), polyether ester amide resin (IRGASTAT P18, manufactured by Ciba Specialty Chemicals) containing sodium perchlorate (C) (B) 80 weights And a resin composition composed of 4.5 parts by weight of a polycarbonate-glycidyl methacrylate-styrene-acrylonitrile copolymer (Modiper C L440-G, manufactured by NOF Corporation) (D), a core having an outer diameter of 10 mm made of stainless steel A charging roller was obtained in the same manner as in Example 1 except that the roller was formed by coating the shaft at 220 ° C. by injection molding to form an electric resistance adjusting layer.

(Comparative Example 4)
Polyetheresteramide resin containing sodium perchlorate (C) (IRGASTAT P18, manufactured by Ciba Specialty Chemicals Co., Ltd.) (B) A resin composition composed of 100 parts by weight is applied to a core shaft made of stainless steel with an outer diameter of 10 mm. A charging roller was obtained in the same manner as in Example 1 except that a roller was formed by coating at 220 ° C. by injection molding to form an electric resistance adjusting layer.

(Comparative Example 5)
Polyether ester amide resin (TPAE-10HP, manufactured by Fuji Kasei Kogyo Co., Ltd.) containing 20 parts by weight of the aliphatic polyketone resin (A) prepared in Example 1 and lithium trifluoromethanesulfonate (C) (B) Except for melt-kneading the resin composition composed of 80 parts by weight at 220 ° C., and coating the core shaft made of stainless steel with an outer diameter of 10 mm by injection molding to form an electric resistance adjusting layer, thereby forming a roller. A charging roller was obtained in the same manner as in Example 1.

(Comparative Example 6)
80 parts by weight of the aliphatic polyketone resin (A) produced in Example 1 above, polyetheresteramide resin (IRGASTAT P18, manufactured by Ciba Specialty Chemicals) containing sodium perchlorate (C) (B) 20 parts by weight, A resin composition composed of 4.5 parts by weight of polycarbonate-glycidyl methacrylate-styrene-acrylonitrile copolymer (Modiper CL 440-G, manufactured by NOF Corporation) (D) is melt kneaded at 220 ° C. A charging roller was obtained in the same manner as in Example 1, except that a core shaft having an outer diameter of 10 mm was coated by injection molding to form an electric resistance adjusting layer to obtain a roller.

  As described above, the following tests 1 to 3 were evaluated for the conductive members (charging rollers) obtained in Examples 1 to 5 and Comparative Examples 1 to 6.

<Test 1> (Evaluation of conductivity)
A disk test piece (TP) having a diameter of 43 mm and a thickness of 1 mm was molded using the molding resin materials of the resistance adjustment layers of Examples 1 to 5 and Comparative Examples 1 to 6. Volume resistance was measured at an applied voltage of 100 V in a standard environment (23 ° C., 50% RH) using a resistance measuring jig that sandwiched and measured the TP from above and below the disk.

<Test 2> (Evaluation of environmental variability in minute gaps)
The conductive members (charging rollers) obtained in Examples 1 to 5 and Comparative Examples 1 to 6 were left in a high temperature and high humidity environment (30 ° C. and 90% RH) for 1 day, and then the image forming apparatus (image MP) shown in FIG. C6000, manufactured by Ricoh Co., Ltd., was used to continuously copy 50,000 sheets of printer paper (type 6200, manufactured by Ricoh) for copying machines in a high-temperature, high-humidity environment (30 ° C. and 90% RH). The presence or absence of image defects due to adhesion of toner or discharge products to the toner was evaluated. At this time, the voltage applied to the charging roller is DC = −700 V, AC Vpp = 2.2 kV (frequency = 2.2 kHz), and continuous copying is performed with the cleaning member 64c in FIG. 3 removed. Accelerated evaluation was performed.

<Test 3> (Evaluation of impact resistance)
The conductive member (charging roller) obtained in Examples 1 to 5 and Comparative Examples 1 to 6 was energized in a state where the roller was not passed using an acceleration test apparatus obtained by modifying the image forming apparatus shown in FIG. An idling test was conducted for 5 days (corresponding to 150,000 copies) to examine whether cracks occurred. At this time, the voltage applied to the charging roller was set to DC = −700 V and AC Vpp = 2.7 kV (frequency = 3 kHz). The evaluation environment was 23 ° C. and 50% RH.

  The evaluation criteria were as follows.

(1) Conductivity ○: TP volume resistance 100V value was 1.0 × 10 ¹¹ Ωcm or less X: TP volume resistance 100V value exceeded 1.0 × 10 ¹¹ Ωcm

(2) Environmental Fluctuation System ○: Image defects caused by deposits such as toner and discharge products adhered to the surface of the charging roller during continuous copying of 50000 sheets ×: During continuous copying of 50000 sheets Image defects caused by adhering materials such as toner and discharge products adhering to the surface of the charging roller

(3) Impact resistance ○: No cracks occurred in the energization idling test ×: No cracks occurred in the energization idling test

(4) Overall evaluation OK: No problem in practical use NG: No problem in practical use

  The evaluation results are shown in the following Table 1.

  Table 1 shows the following. That is, in the conductive part material (charging roller) of Examples 1 to 5, good results were obtained in all the tests, but in the conductive part material (charging roller) of Comparative Examples 1 to 6, all the tests were performed. No good results were observed.

DESCRIPTION OF SYMBOLS 3 Gap holding member 4 Electrical resistance adjustment layer 5 Surface layer 6 Conductive support body 7 Bearing 8 Compression spring 61 Photosensitive drum (image carrier)
101 Conductive member (charging member, charging roller)
G Minute gap

Japanese Patent Laid-Open No. 3-240076 JP-A-4-358175 JP-A-5-107871 Japanese Patent No. 4159901

Claims (10)

  A conductive support, an electrical resistance adjustment layer formed on the conductive support, and the electrical resistance adjustment layer and the image carrier are in contact with the image carrier so as to maintain a certain minute gap. A gap holding member made of a material different from the material of the electrical resistance adjusting layer formed at both ends of the electrical resistance adjusting layer, wherein the electrical resistance adjusting layer is an aliphatic polyketone resin. A conductive member comprising a resin composition containing (A), a polyetheresteramide resin (B), and an electrolyte salt (C).   The blending ratio of the polyetheresteramide resin (B) to the aliphatic polyketone resin (A) in the resin composition: (A) / (B) is 60/40 to 40/60 wt%. The conductive member according to claim 1.   The electroconductivity according to claim 1, wherein the electrolyte salt in the resin composition is at least one electrolyte salt selected from perchlorates, fluorine-containing organic anion salts, and organic phosphonium salts. Element.   The blending ratio of the electrolyte salt (C) to the polyether ester amide resin (B) in the resin composition is 0.01 to 20% by weight. Conductive member.   The graft copolymer (D) having a polycarbonate resin in the main chain and an acrylonitrile-styrene-glycidyl methacrylate copolymer in the side chain is further contained in the resin composition. Conductive member.   It has a polycarbonate resin in the main chain and an acrylonitrile-styrene-glycidyl methacrylate copolymer in the side chain with respect to the total of the aliphatic polyketone resin (A) and the polyether ester amide resin (B) in the resin composition. The blending ratio of the graft copolymer (D): (D) / (A) + (B) is 1 to 15% by weight.   The conductive member according to claim 1, wherein the resin composition is a resin composition obtained by melt-kneading.   The conductive member according to claim 1, wherein the conductive member is a charging member provided so as to be disposed close to the image carrier.   9. A process cartridge, wherein the conductive member according to claim 8 is a process cartridge provided so as to be disposed close to an image carrier.   An image forming apparatus comprising the process cartridge according to claim 9.

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