JP4326588B2

JP4326588B2 - Method for manufacturing conductive member

Info

Publication number: JP4326588B2
Application number: JP2009069531A
Authority: JP
Inventors: 豊成田; 誠中村; 泰輔徳脇; 亜希子田中; 忠幸大島
Original assignee: Ricoh Co Ltd
Current assignee: Ricoh Co Ltd
Priority date: 2009-03-23
Filing date: 2009-03-23
Publication date: 2009-09-09
Anticipated expiration: 2023-09-18
Also published as: JP2009134322A

Description

この発明は、軸部材をなす導電性支持体の両端部を除く中間部の周面に電気抵抗調整層を設けた導電性部材の製造方法に関する。 The present invention relates to a method for manufacturing a conductive member in which an electrical resistance adjusting layer is provided on a peripheral surface of an intermediate portion excluding both ends of a conductive support constituting a shaft member.

従来から、複写機、レーザービームプリンタ、ファクシミリ等の電子写真方式の画像形成装置には、感光体ドラム（像担持体）に対して帯電処理を行う帯電部材や、感光体ドラム上のトナーに対して転写処理を行う転写部材として導電性部材が用いられている。 Conventionally, in an electrophotographic image forming apparatus such as a copying machine, a laser beam printer, and a facsimile, a charging member that charges a photosensitive drum (image carrier) and toner on the photosensitive drum are used. A conductive member is used as a transfer member that performs the transfer process.

図１は、導電性部材を帯電部材として用いた一例を示したものであり、画像形成装置１における帯電ローラ２が帯電部材として用いられている。この画像形成装置１は、静電潜像が形成される感光体ドラム４と、感光体ドラム４に対して帯電処理を行う帯電ローラ２と、帯電ローラ２に電圧を印可するためのパワーパック（電圧印加電源）３と、感光体ドラム４の表面電位を測定する表面電位計５と、感光体ドラム４の静電潜像にトナーを付着させる現像ローラ６と、感光体ドラム４上のトナー像を記録紙Ｓに転写処理する転写ローラ７と、転写処理後の感光体ドラム４をクリーニングするためのクリーニング装置８とを備えている。なお、図２に示すように、感光体ドラム４、帯電ローラ２、現像ローラ６、クリーニング装置８を包括するプロセスカートリッジ９が画像形成装置１内に設置される場合もある。 FIG. 1 shows an example in which a conductive member is used as a charging member. A charging roller 2 in the image forming apparatus 1 is used as a charging member. The image forming apparatus 1 includes a photosensitive drum 4 on which an electrostatic latent image is formed, a charging roller 2 that performs a charging process on the photosensitive drum 4, and a power pack (for applying voltage to the charging roller 2). A voltage application power source 3, a surface potential meter 5 for measuring the surface potential of the photosensitive drum 4, a developing roller 6 for attaching toner to the electrostatic latent image on the photosensitive drum 4, and a toner image on the photosensitive drum 4. Is provided with a transfer roller 7 for transferring the toner image onto the recording paper S and a cleaning device 8 for cleaning the photosensitive drum 4 after the transfer process. As shown in FIG. 2, a process cartridge 9 including the photosensitive drum 4, the charging roller 2, the developing roller 6, and the cleaning device 8 may be installed in the image forming apparatus 1.

帯電ローラ２はパワーパック３より電源供給を受け、感光体ドラム４を所望の電位に帯電させる。この感光体ドラム４は図示を略す駆動機構により矢印Ａ方向に回転する。表面電位計５はその回転方向に沿って帯電ローラ２の直後に設けられ、感光体ドラム４の表面４ａの電位を測定する。 The charging roller 2 is supplied with power from the power pack 3 and charges the photosensitive drum 4 to a desired potential. The photosensitive drum 4 is rotated in the direction of arrow A by a driving mechanism (not shown). The surface potential meter 5 is provided immediately after the charging roller 2 along its rotation direction, and measures the potential of the surface 4 a of the photosensitive drum 4.

現像ローラ６は帯電した感光体ドラム４にトナーを付着させ、転写ローラ７は感光体ドラム４に付着したトナーを記録紙Ｓに転写する。クリーニング装置８は感光体ドラム４に残留したトナーを除去し、感光体ドラム４をクリーニングする。 The developing roller 6 causes the toner to adhere to the charged photosensitive drum 4, and the transfer roller 7 transfers the toner attached to the photosensitive drum 4 to the recording paper S. The cleaning device 8 removes the toner remaining on the photosensitive drum 4 and cleans the photosensitive drum 4.

この画像形成装置１による画像形成過程では、まず、帯電ローラ２により感光体ドラム４の表面４ａが負の高電位に帯電する。続いて、その帯電した表面４ａに原稿からの反射光やレーザー光からなる露光Ｌが照射される。この露光Ｌは、形成しようとする画像の黒／白に応じた光量分布を有し、表面４ａの各部の電位（負の電位）が受光量に合わせて低下することによって表面４ａには光量分布に対応する電位分布、すなわち、静電潜像が形成される。 In the image forming process by the image forming apparatus 1, first, the surface 4 a of the photosensitive drum 4 is charged to a negative high potential by the charging roller 2. Subsequently, the charged surface 4a is irradiated with an exposure L made of reflected light from the original or laser light. This exposure L has a light amount distribution corresponding to the black / white of the image to be formed, and the potential (negative potential) of each part of the surface 4a is lowered according to the amount of received light, whereby the light amount distribution is applied to the surface 4a. Is formed, that is, an electrostatic latent image is formed.

感光体ドラム４が回転してその表面４ａの静電潜像が形成された部分が現像ローラ６を通過すると、表面４ａには電位分布に応じたトナーが付着して静電潜像がトナー像として可視化される。このトナー像は所定のタイミングで給送される記録紙Ｓに転写ローラ７により転写され、記録紙Ｓは図示を略す定着ユニットに向かって矢印Ｂ方向に搬送される。 When the photosensitive drum 4 rotates and the portion of the surface 4a where the electrostatic latent image is formed passes through the developing roller 6, toner corresponding to the potential distribution adheres to the surface 4a, and the electrostatic latent image becomes a toner image. Is visualized as This toner image is transferred to the recording sheet S fed at a predetermined timing by the transfer roller 7, and the recording sheet S is conveyed in the direction of arrow B toward a fixing unit (not shown).

一方、転写後の感光体ドラム４は、表面４ａに残留するトナーがクリーニング装置８により除去されてクリーニングされるとともに、図示を略すクエンチングランプにより残留電荷が除去されて次回の作像処理に移行する。 On the other hand, after the transfer, the photosensitive drum 4 is cleaned by removing the toner remaining on the surface 4a by the cleaning device 8, and the residual charge is removed by a quenching lamp (not shown), and the process proceeds to the next image forming process. To do.

上記の画像形成装置１における一般的な帯電方式として帯電ローラ２を感光体ドラム４に接触させる接触帯電方式が知られている（例えば、特許文献１、特許文献２、特許文献３参照）。 As a general charging method in the image forming apparatus 1 described above, a contact charging method in which the charging roller 2 is brought into contact with the photosensitive drum 4 is known (see, for example, Patent Document 1, Patent Document 2, and Patent Document 3).

しかしながら、接触帯電方式からなる帯電ローラ２を用いた場合には、以下に掲げるような問題があった。 However, when the charging roller 2 of the contact charging system is used, there are the following problems.

（１）帯電ローラの構成物質が帯電ローラから染み出して感光体ドラムの表面に付着し、この付着が進行すると感光体ドラム表面に帯電ローラの跡が残る。 (1) The constituent material of the charging roller oozes out from the charging roller and adheres to the surface of the photosensitive drum, and when this adhesion proceeds, a trace of the charging roller remains on the surface of the photosensitive drum.

（２）帯電ローラに交流電圧を印加した際に、感光体ドラムに接触している帯電ローラが振動して帯電音が起こる。 (2) When an AC voltage is applied to the charging roller, the charging roller in contact with the photosensitive drum vibrates and a charging sound is generated.

（３）感光体ドラム表面のトナーが帯電ローラに付着して帯電性能が低下する。特に帯電ローラにおいて（１）の染出しが生じると、トナーが一層付着しやすくなる。 (3) The toner on the surface of the photosensitive drum adheres to the charging roller and the charging performance is degraded. In particular, when the dyeing of (1) occurs in the charging roller, the toner becomes more easily adhered.

（４）帯電ローラを構成している物質が感光体に付着しやすい。 (4) Substances constituting the charging roller are likely to adhere to the photoreceptor.

（５）感光体ドラムを長期間駆動しないと帯電ローラに永久変形が生じる。 (5) If the photosensitive drum is not driven for a long time, the charging roller is permanently deformed.

このような問題に対処するために、帯電ローラ２を感光体ドラム４に接触するのではなく近接させる近接帯電方式が考案されている（特開平３−２４００７６号公報等）。この近接帯電方式は、帯電ローラ２と感光体ドラム４との最近接距離（以下、空隙という）が０．００５〜０．３ｍｍとなるように両者を対向させ、帯電ローラ２に電圧を印加して感光体ドラム４の帯電を行うものである。近接帯電方式では帯電ローラ２と感光体ドラム４とが接触していないので、接触帯電方式で問題となる「帯電ローラの構成物質の感光体ドラムへの付着」及び「長期間の不使用により生じる帯電ローラの永久変形」は問題とならない。また、「トナーの付着による帯電ローラの帯電性能の低下」に関しても、帯電ローラに付着するトナーが少なくなるため近接帯電方式の方が優れている。 In order to cope with such a problem, a proximity charging method has been devised in which the charging roller 2 is brought close to the photosensitive drum 4 instead of contacting it (Japanese Patent Laid-Open No. 3-240076, etc.). In this proximity charging method, the charging roller 2 and the photosensitive drum 4 are opposed to each other so that the closest distance (hereinafter referred to as a gap) is 0.005 to 0.3 mm, and a voltage is applied to the charging roller 2. Thus, the photosensitive drum 4 is charged. In the proximity charging method, the charging roller 2 and the photosensitive drum 4 are not in contact with each other. Therefore, the problem occurs in the contact charging method, “adhesion of the constituent material of the charging roller to the photosensitive drum” and “non-use for a long time”. “Permanent deformation of the charging roller” is not a problem. Further, regarding the “decrease in charging performance of the charging roller due to toner adhesion”, the proximity charging method is superior because the amount of toner adhering to the charging roller is reduced.

近接帯電方式を実現するものとして、所定の厚みを持ったテープ状の空隙保持手段を帯電ローラの両端部に巻き付けることによって帯電ローラと感光体ドラムとの間に一定間隔の空隙を設ける方法が、例えば、特開平５−１０７８７１号公報において考案されている。しかしながら、テープ状部材の摩耗、帯電ローラとテープ状部材との間へのトナーの侵入・固着等により長期間使用した場合に感光体ドラムと帯電ローラとの空隙を一定間隔に保ち続けることとが困難であるという問題があった。 As a method for realizing the proximity charging method, a method of providing a gap at a constant interval between the charging roller and the photosensitive drum by winding a tape-like gap holding means having a predetermined thickness around both ends of the charging roller, For example, it is devised in JP-A-5-107871. However, the gap between the photosensitive drum and the charging roller may be kept at a constant interval when used for a long period of time due to wear of the tape-like member, toner penetration / fixation between the charging roller and the tape-like member, etc. There was a problem that it was difficult.

また、テープ状部材の摩耗等を防止するためにテープ部材に変えて金属製リングを使用する方法も考えられるが、この場合には感光体ドラムの摩耗が著しいので感光体の基層金属と金属製リングとの間でショート電流が発生して、パワーパック（電圧印加電源）の破壊等の不具合を生じるおそれがあるという問題があった。 In addition, in order to prevent abrasion of the tape-like member, a method of using a metal ring instead of the tape member is conceivable. However, in this case, since the photosensitive drum is extremely worn, the base metal of the photosensitive member and the metallic ring are used. There has been a problem that a short current is generated between the ring and a problem such as destruction of the power pack (voltage applied power source) may occur.

さらに、帯電ローラと感光体ドラムとの空隙を保持するために、帯電ローラ両端部にスペーサーリング層を設ける方法が、例えば、特開平３−２４００７６号公報、特開平４−３５８１７５号公報等において考案されている。しかしながら、これらの公報には、空隙を精度良く一定に保つための具体的な方法が開示されておらず、帯電ローラ及びスペーサーリング層の寸法制度がばらつくことによって空隙が変動し、結果として帯電体ドラムの帯電電位が一定にならないという問題があった。 Further, a method of providing a spacer ring layer at both ends of the charging roller in order to maintain a gap between the charging roller and the photosensitive drum is devised in, for example, Japanese Patent Laid-Open Nos. 3-240076 and 4-358175. Has been. However, these publications do not disclose a specific method for keeping the gap accurately and constant, and the gap varies due to variations in the size system of the charging roller and the spacer ring layer. There was a problem that the charged potential of the drum was not constant.

本発明は、上記の課題に鑑みてなされたものであり、長期にわたって感光体との空隙を精度良く一定に保ち続けることができ、耐久性の高い導電性部材の製造方法を提供することを課題とする。 The present invention has been made in view of the above problems, and it is an object of the present invention to provide a method for producing a highly durable conductive member that can keep the gap between the photoconductor and the photoreceptor accurately over a long period of time. And

請求項１の発明は、軸部材をなす導電性支持体の両端部を除く中間部の周面に電気抵抗調整層を設け、
前記導電性支持体の両端部で、前記電気抵抗調整層と異なる材質からなる空隙調整部材をその一端面を前記電気抵抗調整層の端面にそれぞれ当接固定させて取り付け、
この後、前記空隙調整部材のそれぞれの外周面が感光体の外周面に当接した状態で、前記電気抵抗調整層の外面と感光体の外面との間に空隙が形成されるように、前記一方の空隙調整部材の他端から前記電気抵抗調整層および他方の空気調整部材の他端まで除去加工して、
前記各空隙調整部材の前記電気抵抗調整層に接する側に、前記感光体の外面に接しない少なくとも一つの小径部を形成することを特徴とする。 The invention of claim 1 provides an electrical resistance adjusting layer on the peripheral surface of the intermediate portion excluding both ends of the conductive support constituting the shaft member,
At both ends of the conductive support, a gap adjusting member made of a material different from that of the electric resistance adjusting layer is attached with its one end face abutting and fixed to the end face of the electric resistance adjusting layer,
Thereafter, the gap is formed between the outer surface of the electric resistance adjusting layer and the outer surface of the photosensitive member in a state where the outer peripheral surfaces of the gap adjusting members are in contact with the outer peripheral surface of the photosensitive member. Removal processing from the other end of one gap adjustment member to the other end of the electrical resistance adjustment layer and the other air adjustment member,
At least one small-diameter portion that is not in contact with the outer surface of the photoconductor is formed on a side of the gap adjustment member that is in contact with the electrical resistance adjustment layer.

この発明によれば、空隙保持部材が電気抵抗調整層の端部に固着される別材質からなる部材として設けられており、さらに、空隙保持部材の外表面と、電気抵抗調整層の外表面とには高低差が設けられているので、電気抵抗調整層と感光体との空隙間隔を精度良く一定に保つことが可能となる。また、電気抵調整層と隣接する空隙保持部材の端部は、感光体に当接しないように加工されているので、空隙保持部材の外周面が感光体に接触する幅を狭くすることができる。このため、空隙保持部材と感光体との接触面積が少なくなり、接触箇所の変化に伴う空隙間隔の変化が少なくなるので空隙間隔を精度良く一定に保つことが容易となる。 According to the present invention, the gap holding member is provided as a member made of a different material fixed to the end of the electric resistance adjusting layer, and further, the outer surface of the gap holding member, the outer surface of the electric resistance adjusting layer, Since there is a difference in height, the gap between the electric resistance adjusting layer and the photosensitive member can be kept constant with high accuracy. In addition, since the end of the gap holding member adjacent to the electrical resistance adjusting layer is processed so as not to contact the photoconductor, the width of the outer peripheral surface of the gap holding member in contact with the photoconductor can be reduced. . For this reason, the contact area between the gap holding member and the photosensitive member is reduced, and the change in the gap interval due to the change in the contact location is reduced, so that the gap interval can be easily kept constant with high accuracy.

図１は、一般的な画像形成装置の構成を示した概略図である。FIG. 1 is a schematic diagram illustrating a configuration of a general image forming apparatus. 図２は、プロセスカートリッジを備えた画像形成装置の構成を示した概略図である。FIG. 2 is a schematic diagram illustrating a configuration of an image forming apparatus including a process cartridge. 図３は、本発明に係る帯電ローラ（導電性部材）を示した断面図である。FIG. 3 is a sectional view showing a charging roller (conductive member) according to the present invention. 図４は、本発明に係る帯電ローラと感光体ドラムとの配設関係を示した断面図である。FIG. 4 is a sectional view showing the arrangement relationship between the charging roller and the photosensitive drum according to the present invention. 図５は、本発明に係る帯電ローラにおける抵抗調整層と空隙保持部材との取り付け工程を示した断面図である。FIG. 5 is a cross-sectional view showing a process of attaching the resistance adjusting layer and the gap holding member in the charging roller according to the present invention. 図６は、抵抗調整層と空隙保持部材とが設置された帯電ローラにおいて除去加工を行う工程を示した断面図である。FIG. 6 is a cross-sectional view showing a process of performing removal processing in the charging roller in which the resistance adjusting layer and the gap holding member are installed. 図７は実施例１に係る帯電ローラの除去加工の工程を示した断面拡大図であり、（ａ）は除去加工前を示し、（ｂ）は除去加工後を示している。7A and 7B are enlarged cross-sectional views illustrating the process of removing the charging roller according to the first embodiment. FIG. 7A illustrates the state before the removal process, and FIG. 7B illustrates the process after the removal process. 図８は、実施例１に係る帯電ローラの端部を示した拡大断面図である。FIG. 8 is an enlarged cross-sectional view illustrating an end portion of the charging roller according to the first embodiment. 図９は実施例２に係る帯電ローラの除去加工の工程を示した断面拡大図であり、（ａ）は除去加工前を示し、（ｂ）は除去加工後を示している。FIGS. 9A and 9B are enlarged cross-sectional views illustrating the process of removing the charging roller according to the second embodiment. FIG. 9A illustrates the state before the removal process, and FIG. 図１０は、実施例２に係る帯電ローラの端部を示した拡大断面図である。FIG. 10 is an enlarged cross-sectional view illustrating an end portion of the charging roller according to the second embodiment. 図１１は、実施例３に係る帯電ローラの端部を示した拡大断面図であるFIG. 11 is an enlarged cross-sectional view illustrating an end portion of the charging roller according to the third embodiment. 図１２は、実施例４に係る帯電ローラの端部を示した拡大断面図である。FIG. 12 is an enlarged cross-sectional view illustrating an end portion of the charging roller according to the fourth embodiment. 図１３は、実施例５に係る帯電ローラの端部を示した拡大断面図である。FIG. 13 is an enlarged cross-sectional view illustrating an end portion of the charging roller according to the fifth embodiment. 図１４は、実施例６に係る帯電ローラの端部を示した拡大断面図である。FIG. 14 is an enlarged cross-sectional view illustrating an end portion of the charging roller according to the sixth embodiment.

以下、本発明に係る導電性部材を、図面を用いて詳細に説明する。 Hereinafter, the electroconductive member which concerns on this invention is demonstrated in detail using drawing.

図３は、画像形成装置１の帯電ローラ２として使用される導電性部材の構成を示した断面図である。なお、具体的な画像形成装置１の構成は、図１を用いて背景技術において説明した内容と同様であるため、ここでの詳細な説明は省略する。 FIG. 3 is a cross-sectional view illustrating a configuration of a conductive member used as the charging roller 2 of the image forming apparatus 1. Note that the specific configuration of the image forming apparatus 1 is the same as that described in the background art with reference to FIG. 1, and thus detailed description thereof is omitted.

帯電ローラ２は、近接帯電方式の帯電ローラであって、導電性支持体１０と、抵抗調整層１１と、空隙保持部材１２とを備えている。導電性支持体１０は、長尺の円柱形状を呈しており、この端部には帯電ローラ２に電圧を印可するためのパワーパック（電圧印加電源）３が接続される。 The charging roller 2 is a proximity charging type charging roller, and includes a conductive support 10, a resistance adjustment layer 11, and a gap holding member 12. The conductive support 10 has a long cylindrical shape, and a power pack (voltage application power source) 3 for applying a voltage to the charging roller 2 is connected to the end of the conductive support 10.

抵抗調整層１１は、導電性支持体１０を中心軸として導電性支持体１０の周面部に設置された円筒状を呈している。空隙保持部材１２も、導電性支持体１０を中心軸として導電性支持体１０の周面部に設置された円筒状を呈している。 The resistance adjustment layer 11 has a cylindrical shape installed on the peripheral surface portion of the conductive support 10 with the conductive support 10 as a central axis. The gap holding member 12 also has a cylindrical shape installed on the peripheral surface portion of the conductive support 10 with the conductive support 10 as a central axis.

図４は図３に示す帯電ローラ２を感光体ドラム４に隣接設置した様子を示した模式図である。帯電ローラ２は感光体ドラム４に対して任意の圧力で当接されて配置される。この帯電ローラ２は、近接帯電方式となっており、抵抗調整層１１の外径が空隙保持部材１２の外径に対して僅かに小径に形成され、帯電ローラ２の空隙保持部材１２の外周面１２ａは感光体ドラム４の外周面４ａに当接するが、抵抗調整層１１の外表面１１ａと感光体ドラムの外表面４ａとの間には空隙１５が形成されている。さらに、帯電ローラ２は、空隙保持部材１２が感光体ドラム４の画像形成領域以外の領域（非画像形成領域）に当接するようにして設置されている。この状態で帯電ローラ２に電圧を印加することにより、感光体ドラム４を帯電させることが可能となる。 FIG. 4 is a schematic view showing a state where the charging roller 2 shown in FIG. 3 is installed adjacent to the photosensitive drum 4. The charging roller 2 is disposed in contact with the photosensitive drum 4 with an arbitrary pressure. The charging roller 2 is a proximity charging system, and the outer diameter of the resistance adjusting layer 11 is slightly smaller than the outer diameter of the gap holding member 12, and the outer peripheral surface of the gap holding member 12 of the charging roller 2. 12a abuts on the outer peripheral surface 4a of the photosensitive drum 4, and a gap 15 is formed between the outer surface 11a of the resistance adjusting layer 11 and the outer surface 4a of the photosensitive drum. Further, the charging roller 2 is installed such that the gap holding member 12 is in contact with an area (non-image forming area) other than the image forming area of the photosensitive drum 4. By applying a voltage to the charging roller 2 in this state, the photosensitive drum 4 can be charged.

また、感光体ドラム４は、円筒形状を呈している。このため、帯電ローラ２と感光体ドラム４とを回転駆動させることによって、互いに対向する面を回転に伴って変化させることができるので通電ストレスによる表面の化学的劣化が生じにくくなり、製品寿命を高めることが可能となる。なお、感光体ドラム４と帯電ローラ２とは互いに円筒形状を呈している必要は必ずしもなく、楕円筒状等であっても良い。 The photosensitive drum 4 has a cylindrical shape. For this reason, since the charging roller 2 and the photosensitive drum 4 are rotationally driven, the surfaces facing each other can be changed with the rotation, so that chemical degradation of the surface due to energization stress is less likely to occur, and the product life is shortened. It becomes possible to raise. Note that the photosensitive drum 4 and the charging roller 2 do not necessarily have a cylindrical shape, and may have an elliptical cylindrical shape.

帯電ローラ２は、近接帯電方式を採用するため、空隙１５の間隔を所定間隔に保つ必要がある。このため、図４に示すように感光体ドラム４の画像形成領域と非画像形成領域との外表面が同一高さ（面一）である場合は、空隙保持部材１２における感光体ドラム４との当接部分の高さ（導電性支持体の中心軸からの外径）が抵抗調整層１１の外表面の高さ（同中心軸からの外形）よりも高いことが必要であり、その高低差、つまり空隙１５間隔は、０．１ｍｍ以下であることが望ましい。空隙１５が大きくなると帯電ローラに対する電圧印加条件を高くする必要があり、感光体ドラム４の電気的劣化や異常放電が発生しやすくなるためである。 Since the charging roller 2 employs the proximity charging method, it is necessary to keep the gap 15 at a predetermined interval. For this reason, as shown in FIG. 4, when the outer surfaces of the image forming area and the non-image forming area of the photosensitive drum 4 are the same height (level), the gap holding member 12 and the photosensitive drum 4 The height of the contact portion (the outer diameter from the central axis of the conductive support) needs to be higher than the height of the outer surface of the resistance adjusting layer 11 (the outer shape from the central axis). That is, it is desirable that the gap 15 interval is 0.1 mm or less. This is because when the gap 15 is increased, it is necessary to increase the voltage application condition for the charging roller, and electrical deterioration and abnormal discharge of the photosensitive drum 4 are likely to occur.

また、空隙保持部材１２の抵抗調整層１１と隣接する部分の高さを、他の部分に較べて低く加工することによって、空隙保持部材１２の外表面１２ａと感光体ドラム４の外表面４ａとの接触幅が低減され、導電性部材１１と感光体ドラム４との空隙１５間隔を高精度に保つことが可能となる。 Further, by processing the height of the portion adjacent to the resistance adjustment layer 11 of the gap holding member 12 to be lower than that of other portions, the outer surface 12a of the gap holding member 12 and the outer surface 4a of the photosensitive drum 4 Thus, the gap 15 between the conductive member 11 and the photosensitive drum 4 can be maintained with high accuracy.

次に、帯電ローラ２における空隙の形成方法を説明する。まず、帯電ローラは、図５に示すように、円柱状を呈する抵抗調整層１１の挿通孔１１oに対して導電性支持体１０を挿通させ、その後に空隙保持部材１２を抵抗調整層１１の両端から嵌め込む。ここで、空隙保持部材１２の端面１２ｂと抵抗調整層１１の端面１１ｂおよび導電性支持体１０の周面部と空隙保持部材１２における挿通孔内面１２ｃとの間に接着剤を塗布することで、空隙保持部材１２が使用によって容易に脱離することを防止することが可能となる。 Next, a method for forming a gap in the charging roller 2 will be described. First, as shown in FIG. 5, in the charging roller, the conductive support 10 is inserted into the insertion hole 11 o of the resistance adjustment layer 11 having a columnar shape, and then the gap holding member 12 is connected to both ends of the resistance adjustment layer 11. Fit from. Here, by applying an adhesive between the end face 12 b of the gap holding member 12, the end face 11 b of the resistance adjusting layer 11, the peripheral surface portion of the conductive support 10, and the insertion hole inner face 12 c in the gap holding member 12, It becomes possible to prevent the holding member 12 from being easily detached by use.

次に、導電性支持体１０に抵抗調整層１１と空隙保持部材１２とが取り付けられた帯電ローラ２に対して、空隙保持部材１２の外表面１２ａと抵抗調整層１１の外表面１１ａとに対して連続して除去加工を施す。ここで、除去加工とは切削処理又は研磨処理等により外表面の表面調整処理を行う加工を意味するものであり、空隙保持部材１２の外表面１２ａの高さと抵抗調整層１１の外表面１１ａの高さとの高低差を所望の空隙間隔に応じて調整する作業を意味する。この除去加工によって高低差のばらつきを±０．０１ｍｍ以下に抑えることが可能となる。 Next, with respect to the charging roller 2 in which the resistance adjustment layer 11 and the gap holding member 12 are attached to the conductive support 10, the outer surface 12 a of the gap holding member 12 and the outer surface 11 a of the resistance adjustment layer 11 are The removal process is performed continuously. Here, the removal process means a process of performing a surface adjustment process of the outer surface by a cutting process or a polishing process, and the height of the outer surface 12a of the gap holding member 12 and the outer surface 11a of the resistance adjustment layer 11 are defined. It means an operation of adjusting the height difference from the height according to the desired gap interval. By this removal processing, the variation in height difference can be suppressed to ± 0.01 mm or less.

具体的には、図６に示すように、まず空隙保持部材１２の端部から一定距離Ｌだけ水平に外表面１２ａを切削刃１６で切削処理し、その後、抵抗調整層側１１に隣接する空隙保持部材１２の端部１２ｄを更に深く除去する。抵抗調整層１１に隣接する空隙保持部材１２の端部１２ｄを抵抗調整層１１の外表面１１ａと面一又は僅かに低くなるよう除去加工した後に、抵抗調整部１１の外表面１１ａに対して空隙保持部材１２の外表面１２ａが一定高低差を保つようにして除去加工を施す。反対側端部に設けられる空隙保持部材１２に対しても同様に除去加工を施す。 Specifically, as shown in FIG. 6, first, the outer surface 12a is cut by the cutting blade 16 horizontally by a fixed distance L from the end of the gap holding member 12, and then the gap adjacent to the resistance adjustment layer side 11 is cut. The end 12d of the holding member 12 is further removed deeply. After removing the end 12d of the gap holding member 12 adjacent to the resistance adjustment layer 11 so as to be flush with or slightly lower than the outer surface 11a of the resistance adjustment layer 11, the gap is formed with respect to the outer surface 11a of the resistance adjustment section 11. Removal processing is performed so that the outer surface 12a of the holding member 12 maintains a certain level difference. Removal processing is similarly performed on the gap holding member 12 provided at the opposite end.

このように加工を行うことによって、空隙保持部材１２の外表面１２ａと抵抗調整層１１の外表面１１ａとの間に空隙１５が形成される。また、空隙保持部材１２の抵抗調整層１１側の端部１２ｄの外表面が空隙保持部材１２の外表面１２ａに対して低くなるので、空隙保持部材１２の抵抗調整層１１側端部１２ｄの外表面が感光体ドラム４に当接することを防止することができ、この端部１２ｄを介して隣接する抵抗調整層１１が感光体ドラム４に接触してショート電流が発生してしまうことを防止することが可能となる。また、空隙保持部１２の抵抗調整層１１側の端部１２ｄを低く加工することによって、この部分を、除去加工を行う際の切削刃１６等の逃げシロ（逃げ加工）とすることができる。さらに、空隙保持部材１２の端部１２ｄが感光体ドラム４に当接しないことによって、空隙保持部材１２の外表面１２ａと感光体ドラム４の外表面４ａとの当接幅が狭くなり、当接箇所の変化に伴う空隙間隔の変化が少なくなるので空隙の精度より一層高く保つことが容易となる。 By performing the processing in this way, a gap 15 is formed between the outer surface 12 a of the gap holding member 12 and the outer surface 11 a of the resistance adjustment layer 11. Further, since the outer surface of the end portion 12d on the resistance adjustment layer 11 side of the gap holding member 12 is lower than the outer surface 12a of the gap holding member 12, the outer surface of the end portion 12d on the resistance adjustment layer 11 side of the gap holding member 12 is reduced. It is possible to prevent the surface from coming into contact with the photosensitive drum 4 and to prevent the adjacent resistance adjusting layer 11 from contacting the photosensitive drum 4 through the end portion 12d and generating a short current. It becomes possible. Further, by processing the end 12d on the resistance adjustment layer 11 side of the gap holding portion 12 to be low, this portion can be used as a relief for the cutting blade 16 or the like when performing the removal processing. Further, since the end 12d of the gap holding member 12 does not come into contact with the photosensitive drum 4, the contact width between the outer surface 12a of the gap holding member 12 and the outer surface 4a of the photosensitive drum 4 is reduced, and the contact is made. Since the change of the space | gap space | interval accompanying the change of a location becomes small, it becomes easy to keep higher than the precision of a space | gap.

なお、逃げシロ（逃げ加工）の形状は、空隙保持部１２の端部１２ｄの外表面が感光体ドラム４に当接しないような形状であるならばどのような形状であっても良い。 The shape of relief (relief processing) may be any shape as long as the outer surface of the end portion 12 d of the gap holding portion 12 does not contact the photosensitive drum 4.

空隙保持部材１２は、感光体ドラム４との当接時に基層とショートしてショート電流が発生することを防止するために絶縁性材料であることが好ましく、特に、体積固有抵抗で１０１３Ω・ｃｍ以上であることが望ましい。また、空隙保持部材１２の全部が絶縁性材料である必要はなく、少なくとも抵抗調整層１１との当接部分等が絶縁性を備えているものであるならばショート電流の発生を防止することが可能となる。 The gap holding member 12 is preferably an insulating material in order to prevent a short-circuit from occurring due to a short circuit with the base layer when contacting the photosensitive drum 4, and in particular, a volume specific resistance of 1013 Ω · cm or more. It is desirable that Further, it is not necessary for the entire gap holding member 12 to be made of an insulating material, and if at least a contact portion with the resistance adjusting layer 11 has an insulating property, it is possible to prevent the occurrence of a short current. It becomes possible.

また、空隙保持部材１２の材料は、絶縁性の他に特に限定されるものではないが、感光体ドラム４を傷つけない程度に軟らかく、また成形加工が容易であること等の理由から、高密度ポリエチレン等の熱可塑性樹脂等であることが好ましい。 The material of the gap holding member 12 is not particularly limited in addition to the insulating property, but it has a high density because it is soft enough not to damage the photosensitive drum 4 and easy to form. A thermoplastic resin such as polyethylene is preferred.

抵抗調整層１１は、高分子型イオン導電材料が分散された熱可塑性樹脂組成物により形成されている。抵抗調整層１１の体積固有抵抗は、１０９Ωcmを越えると、帯電能力や転写能力が不足してしまい、１０６Ωcmよりも体積固有抵抗が低いと、感光体ドラム４全体への電圧集中によるリークが生じてしまうので、１０６〜１０９Ωcmであることが望ましい。 The resistance adjustment layer 11 is formed of a thermoplastic resin composition in which a polymer type ion conductive material is dispersed. If the volume resistivity of the resistance adjusting layer 11 exceeds 109 Ωcm, charging ability and transfer ability are insufficient, and if the volume resistivity is lower than 106 Ωcm, leakage due to voltage concentration on the entire photosensitive drum 4 occurs. Therefore, it is desirable that it is 106-109 ohm-cm.

また、抵抗調整層１１に用いられる熱可塑性樹脂は特に限定されるものではないが、ポリエチレン（ＰＥ）、ポリプロピレン（ＰＰ）、ポリメタクリル酸メチル（ＰＭＭＡ）、ポリスチレン（ＰＳ）およびその共重合体（ＡＳ、ＡＢＳ）等の汎用樹脂であれば、成形加工が容易でありより好ましい。その熱可塑性樹脂に分散させる高分子型イオン導電材料としては、ポリエーテルエステルアミド成分を含有する高分子化合物が好ましい。ポリエーテルエステルアミドはイオン導電性の高分子材料であり、マトリクスポリマー中に分子レベルで均一に分散・固定化される。したがって、導電性顔料を分散した組成物に見られるような分散不良に伴う抵抗値のバラツキが生じない。また高分子材料であるため、ブリードアウトが生じ難い。配合量については、抵抗値を所望の値にする必要があることから、熱可塑性樹脂が３０〜７０重量％、高分子型イオン導電材が７０〜３０重量％とする必要がある。 Moreover, the thermoplastic resin used for the resistance adjusting layer 11 is not particularly limited, but polyethylene (PE), polypropylene (PP), polymethyl methacrylate (PMMA), polystyrene (PS) and a copolymer thereof ( A general-purpose resin such as AS or ABS is more preferable because it can be easily molded. The polymer type ion conductive material dispersed in the thermoplastic resin is preferably a polymer compound containing a polyether ester amide component. Polyether ester amide is an ion conductive polymer material, and is uniformly dispersed and immobilized at a molecular level in a matrix polymer. Therefore, there is no variation in resistance value due to poor dispersion as seen in a composition in which a conductive pigment is dispersed. In addition, since it is a polymer material, bleed-out hardly occurs. About a compounding quantity, since it is necessary to make resistance value into a desired value, it is necessary to make a thermoplastic resin into 30 to 70 weight% and a polymeric ion conductive material to 70 to 30 weight%.

樹脂組成物の製造方法に関しては特に制限はなく、各材料の混合物を二軸混練機、ニーダー等で溶融混練することによって、容易に製造できる。抵抗調整層１１を導電性支持体１０の周面部に形成する工程は、押出成形や射出成形等の手段で導電性支持体１０に上記半導電性樹脂組成物を被覆することによって、容易に行うことができる。 There is no restriction | limiting in particular regarding the manufacturing method of a resin composition, It can manufacture easily by melt-kneading the mixture of each material with a biaxial kneader, a kneader, etc. The step of forming the resistance adjusting layer 11 on the peripheral surface portion of the conductive support 10 is easily performed by coating the conductive support 10 with the semiconductive resin composition by means such as extrusion molding or injection molding. be able to.

また、導電性支持体１０上に抵抗調整層１１のみを形成して帯電ローラ２を構成すると、抵抗調整層１１にトナー等が固着して性能低下を招くおそれがある。このような不具合を防止するために、抵抗調整層１１の外表面にはトナーの固着を防止する表面層が形成されている。表面層の形成によって、感光体ドラム４表面のトナーが抵抗調整層１１の表面に付着することにより発生する不具合を防止することができ、帯電ローラ２の製品寿命を高めることが可能となる。 Further, if only the resistance adjustment layer 11 is formed on the conductive support 10 to constitute the charging roller 2, there is a risk that toner or the like adheres to the resistance adjustment layer 11 and performance is deteriorated. In order to prevent such a problem, a surface layer that prevents toner from sticking is formed on the outer surface of the resistance adjustment layer 11. By forming the surface layer, it is possible to prevent problems caused by the toner on the surface of the photosensitive drum 4 adhering to the surface of the resistance adjusting layer 11, and to increase the product life of the charging roller 2.

なお、表面層の抵抗値は抵抗調整層１１の抵抗値よりも大きくなるように形成されており、この抵抗値の差により感光体ドラムの欠陥部への電圧集中、異常放電(リーク)を回避することが可能となる。なお、表面層の抵抗値を高くしすぎると帯電能力や転写能力が不足してしまうため、表面層と抵抗調整層１１との抵抗値の差は１０３Ωcm以下であることが好ましい。 The resistance value of the surface layer is formed so as to be larger than the resistance value of the resistance adjustment layer 11, and voltage difference and abnormal discharge (leakage) to the defective portion of the photosensitive drum are avoided by the difference in resistance value. It becomes possible to do. If the resistance value of the surface layer is too high, charging ability and transfer ability are insufficient. Therefore, the difference in resistance value between the surface layer and the resistance adjusting layer 11 is preferably 103 Ωcm or less.

表面層を形成する材料としては、製膜性が良好であるという点で熱可塑性樹脂組成物が好適である。樹脂材料としては、フッ素樹脂、シリコーン樹脂、ポリアミド樹脂、ポリエステル樹脂等が非粘着性に優れ、トナー固着防止の面で好ましい。また樹脂材料は電気的に絶縁性であるため、樹脂に対して各種導電材料を分散することによって表面層の抵抗を調整することが可能である。表面層を抵抗調整層１１上へ形成する工程は、上記表面層構成材料を有機溶媒に分散して塗料を作製し、スプレー塗装、ディッピング等によってコーティングすることによって行う。膜厚については、０．０１〜０．０３ｍｍ程度であることが望ましい。 As the material for forming the surface layer, a thermoplastic resin composition is preferable in that the film-forming property is good. As the resin material, fluorine resin, silicone resin, polyamide resin, polyester resin and the like are excellent in non-adhesiveness, and are preferable in terms of preventing toner adhesion. Further, since the resin material is electrically insulating, it is possible to adjust the resistance of the surface layer by dispersing various conductive materials in the resin. The step of forming the surface layer on the resistance adjusting layer 11 is performed by dispersing the surface layer constituting material in an organic solvent to prepare a paint, and coating it by spray coating, dipping or the like. About a film thickness, it is desirable that it is about 0.01-0.03 mm.

以下、上記した帯電ローラであって使用される材料等が異なる複数の実施例１〜実施例６と比較例１〜３を用いて、画像形成処理の比較を行った。 Hereinafter, the image forming process was compared using a plurality of Examples 1 to 6 and Comparative Examples 1 to 3 which are the above-described charging rollers and used different materials.

〈実施例１〉
ステンレスからなる芯軸（導電性支持体１０：外径８ｍｍ）に対して、抵抗調整層１１としてＡＢＳ樹脂（デンカＡＢＳＧＲ−０５００、電気化学工業製）５０重量％、ポリエーテルエステルアミド（ＩＲＧＡＳＴＡＴＰ１８、チバスペシャリティケミカルズ社製）５０重量％からなる樹脂組成物（体積固有抵抗：２×１０８Ωcm）を、射出成形により被覆した。次いでこの両端部に、高密度ポリエチレン樹脂（ノバテックＰＰＨＹ５４０、日本ポリケム社製）からなるリング状の空隙保持部材１２を挿入接着し、切削によって図７に示すように空隙保持部材の外径（最大径）を１２．１２ｍｍ、抵抗調整層の外径を１２．００ｍｍにして同時に仕上げを行い、図８に示す形状とした。次いで抵抗調整層１１の外表面に、アクリルシリコン樹脂（３０００ＶＨ-Ｐ、川上塗料製）、イソシアネート系硬化剤、及びカーボンブラック(全固形分に対して３５重量％)からなる混合物（表面抵抗：２×１０９Ω）により膜厚約０．０１ｍｍの表面層を形成した。
〈実施例２〉
ステンレスからなる芯軸（導電性支持体１０：外径８ｍｍ）に、抵抗調整層１１としてＡＢＳ樹脂（デンカＡＢＳＧＲ−０５００、電気化学工業製）５０重量％、ポリエーテルエステルアミド（ＩＲＧＡＳＴＡＴＰ１８、チバスペシャリティケミカルズ社製）５０重量％からなる樹脂組成物（体積固有抵抗：２×１０８Ωcm）を、射出成形により被覆した。次いでこの両端部に、高密度ポリエチレン樹脂（ノバテックＰＰＨＹ５４０、日本ポリケム社製）からなるリング状の空隙保持部材１２を挿入接着し、切削によって図９に示すように空隙保持部材１２の外径（最大径）を１２．１２ｍｍ、抵抗調整層１１の外径を１２．００ｍｍにして同時に仕上げを行い、図１０に示す形状とした。次いで抵抗調整層１１の表面に、アクリルシリコン樹脂（３０００ＶＨ-Ｐ、川上塗料製）、イソシアネート系硬化剤、及びカーボンブラック(全固形分に対して３５重量％)からなる混合物（表面抵抗：２×１０９Ω）により膜厚約０．０１ｍｍの表面層を形成した。
〈実施例３〉
ステンレスからなる芯軸（導電性支持体１０：外径８ｍｍ）に、抵抗調整層１１としてＡＢＳ樹脂（デンカＡＢＳＧＲ−０５００、電気化学工業製）５０重量％、ポリエーテルエステルアミド（ＩＲＧＡＳＴＡＴＰ１８、チバスペシャリティケミカルズ社製）５０重量％からなる樹脂組成物（体積固有抵抗：２×１０８Ωcm）を、射出成形により被覆した。次いでこの両端部に、高密度ポリエチレン樹脂（ノバテックＰＰＨＹ５４０、日本ポリケム社製）からなるリング状の空隙保持部材１２を挿入接着し、切削によって空隙保持部材１２の外径（最大径）を１２．１２ｍｍ、抵抗調整層１１の外径を１２．００ｍｍにして同時に仕上げを行い、図１１に示す形状とした。次いで抵抗調整層１１の表面に、アクリルシリコン樹脂（３０００ＶＨ-Ｐ、川上塗料製）、イソシアネート系硬化剤、及びカーボンブラック(全固形分に対して３５重量％)からなる混合物（表面抵抗：２×１０９Ω）により膜厚約０．０１ｍｍの表面層を形成した。
〈実施例４〉
ステンレスからなる芯軸（帯電性支持体１０：外径８ｍｍ）に、抵抗調整層としてＡＢＳ樹脂（デンカＡＢＳＧＲ−０５００、電気化学工業製）５０重量％、ポリエーテルエステルアミド（ＩＲＧＡＳＴＡＴＰ１８、チバスペシャリティケミカルズ社製）５０重量％からなる樹脂組成物（体積固有抵抗：２×１０８Ωcm）を、射出成形により被覆した。次いでこの両端部に、高密度ポリエチレン樹脂（ノバテックＰＰＨＹ５４０、日本ポリケム社製）からなるリング状の空隙保持部材１２を挿入接着し、切削によって空隙保持部材１２の外径（最大径）を１２．１２ｍｍ、抵抗調整層１１の外径を１２．００ｍｍにして同時に仕上げを行い、図１２に示す形状とした。次いで抵抗調整層の表面に、アクリルシリコン樹脂（３０００ＶＨ-Ｐ、川上塗料製）、イソシアネート系硬化剤、及びカーボンブラック(全固形分に対して３５重量％)からなる混合物（表面抵抗：２×１０９Ω）により膜厚約０．０１ｍｍの表面層を形成した。
〈実施例５〉
ステンレスからなる芯軸（耐電性支持体１０：外径８ｍｍ）に、抵抗調整層１１としてＡＢＳ樹脂（デンカＡＢＳＧＲ−０５００、電気化学工業製）５０重量％、ポリエーテルエステルアミド（ＩＲＧＡＳＴＡＴＰ１８、チバスペシャリティケミカルズ社製）５０重量％からなる樹脂組成物（体積固有抵抗：２×１０８Ωcm）を、射出成形により被覆した。次いでこの両端部に、高密度ポリエチレン樹脂（ノバテックＰＰＨＹ５４０、日本ポリケム社製）からなるリング状の空隙保持部材１２を挿入接着し、切削によって空隙保持部材１２の外径（最大径）を１２．１２ｍｍ、抵抗調整層１１の外径を１２．００ｍｍに同時仕上げを行い、図１３に示す形状とした。次いで抵抗調整層１１の表面に、アクリルシリコン樹脂（３０００ＶＨ-Ｐ、川上塗料製）、イソシアネート系硬化剤、及びカーボンブラック(全固形分に対して３５重量％)からなる混合物（表面抵抗：２×１０９Ω）により膜厚約０．０１ｍｍの表面層を形成した。
〈実施例６〉
ステンレスからなる芯軸（導電性支持体１０：外径８ｍｍ）に、抵抗調整層１１としてＡＢＳ樹脂（デンカＡＢＳＧＲ−０５００、電気化学工業製）５０重量％、ポリエーテルエステルアミド（ＩＲＧＡＳＴＡＴＰ１８、チバスペシャリティケミカルズ社製）５０重量％からなる樹脂組成物（体積固有抵抗：２×１０８Ωcm）を、射出成形により被覆した。次いでこの両端部に、高密度ポリエチレン樹脂（ノバテックＰＰＨＹ５４０、日本ポリケム社製）からなるリング状の空隙保持部材１２を挿入接着し、切削によって空隙保持部材１２の外径（最大径）を１２．１２ｍｍ、抵抗調整層１１の外径を１２．００ｍｍにして同時に仕上げを行い、図１４に示す形状とした。次いで抵抗調整層１１の表面に、アクリルシリコン樹脂（３０００ＶＨ-Ｐ、川上塗料製）、イソシアネート系硬化剤、及びカーボンブラック(全固形分に対して３５重量％)からなる混合物（表面抵抗：２×１０９Ω）により膜厚約０．０１ｍｍの表面層を形成した。
〈比較例１〉
ステンレスからなる芯軸（外径８ｍｍ）に、抵抗調整層としてエピクロルヒドリンゴム（エピクロマーＣＧ、ダイソー社製）１００重量部に過塩素酸アンモニウム３重量部を配合したゴム組成物（体積固有抵抗：４×１０８Ωcm）を、押出成形、加硫工程を経て被覆し、研削により外径１２ｍｍに仕上げた。次いでこの表面に、ポリビニルブチラール樹脂（デンカブチラール３０００−Ｋ、電気化学工業社製）、イソシアネート系硬化剤、及び酸化スズ(全固形分に対して６０重量％)からなる混合物（表面抵抗：２×１０１０Ω）により膜厚０．０１ｍｍの表面層を形成した。次いでこの両端部周囲に厚さ０．０５ｍｍのテープ状部材（ダイタックＰＦ０２５−Ｈ、大日本インキ社製）を貼り付け、帯電ローラを形成した。
〈比較例２〉
ステンレスからなる芯軸（外径８ｍｍ）に、抵抗調整層としてＡＢＳ樹脂（ＧＲ−０５００、電気化学工業製）５０重量％、四級アンモニウム塩基を含有するイオン導電性の高分子化合物（レオレックスＡＳ−１７２０、第一工業製薬製）５０重量％からなる樹脂組成物（体積固有抵抗：２×１０８Ωcm）を、射出成形により被覆し、切削加工によって外径１２．０ｍｍに仕上げた。次いで抵抗調整層の表面に、フッ素樹脂（ルミフロンＬＦ−６００、旭硝子社製）、イソシアネート系硬化剤、及び酸化スズ(全固形分に対して６０重量％)からなる混合物（表面抵抗：２×１０１０Ω）により膜厚約０．０１ｍｍの表面層を形成した。次いでこの両端部に、ステンレス鋼からなるリング状の空隙保持部材（外径１２．１２ｍｍ）を挿入接着し、帯電ローラを形成した。
〈比較例３〉
ステンレスからなる芯軸（外径８ｍｍ）に、抵抗調整層としてＡＢＳ樹脂（デンカＡＢＳＧＲ−０５００、電気化学工業製）５０重量％、ポリエーテルエステルアミド（ＩＲＧＡＳＴＡＴＰ１８、チバスペシャリティケミカルズ社製）５０重量％からなる樹脂組成物（体積固有抵抗：２×１０８Ωcm）を、射出成形により被覆し外径を１２．０ｍｍとした。次いで抵抗調整層の表面に、フッ素樹脂（ルミフロンＬＦ−６００、旭硝子社製）、イソシアネート系硬化剤、及び酸化スズ(全固形分に対して６０重量％)からなる混合物（表面抵抗：２×１０１０Ω）により膜厚約０．０１ｍｍの表面層を形成した。次いでこの両端部に、ポリアミド樹脂（ノバミッド１０１０Ｃ２、三菱エンジニアリングプラスチックス社製）からなるリング状の空隙保持部材（外径１２．１２ｍｍ）を挿入接着し、帯電ローラを形成した。
〈試験〉
上述した帯電ローラを、図１に示した画像形成装置に搭載し、帯電ローラと感光体間との間に形成される空隙の間隔を測定した。 <Example 1>
With respect to the core shaft made of stainless steel (conductive support 10: outer diameter 8 mm), ABS resin (DENKA ABS GR-0500, manufactured by Denki Kagaku Kogyo Co., Ltd.) 50% by weight as a resistance adjustment layer 11, polyether ester amide (IRGASTAT P18 A resin composition (volume resistivity: 2 × 10 8 Ωcm) consisting of 50% by weight (manufactured by Ciba Specialty Chemicals) was coated by injection molding. Next, a ring-shaped gap holding member 12 made of a high-density polyethylene resin (Novatec PP HY540, manufactured by Nippon Polychem) is inserted and bonded to both ends, and the outer diameter (maximum) of the gap holding member is maximized by cutting as shown in FIG. (Diameter) was set to 12.12 mm, the outer diameter of the resistance adjusting layer was set to 12.00 mm, and finishing was performed at the same time to obtain the shape shown in FIG. Next, on the outer surface of the resistance adjusting layer 11, a mixture (surface resistance: 2) composed of acrylic silicon resin (3000VH-P, manufactured by Kawakami Paint), isocyanate curing agent, and carbon black (35% by weight based on the total solid content). A surface layer having a film thickness of about 0.01 mm was formed by × 109Ω.
<Example 2>
Stainless steel core shaft (conductive support 10: outer diameter 8 mm), ABS resin (Denka ABS GR-0500, manufactured by Denki Kagaku Kogyo Co., Ltd.) 50% by weight as resistance adjustment layer 11, polyether ester amide (IRGASTAT P18, Ciba A resin composition (volume resistivity: 2 × 10 8 Ωcm) consisting of 50% by weight (made by Specialty Chemicals) was coated by injection molding. Next, a ring-shaped gap holding member 12 made of high-density polyethylene resin (Novatech PP HY540, manufactured by Nippon Polychem Co., Ltd.) is inserted and bonded to both ends, and the outer diameter of the gap holding member 12 is cut by cutting as shown in FIG. The maximum diameter was 12.12 mm, the outer diameter of the resistance adjustment layer 11 was 12.00 mm, and finishing was performed at the same time to obtain the shape shown in FIG. Next, on the surface of the resistance adjusting layer 11, a mixture (surface resistance: 2 ×) composed of acrylic silicon resin (3000VH-P, manufactured by Kawakami Paint), isocyanate curing agent, and carbon black (35% by weight with respect to the total solid content). 109Ω) to form a surface layer having a film thickness of about 0.01 mm.
<Example 3>
Stainless steel core shaft (conductive support 10: outer diameter 8 mm), ABS resin (Denka ABS GR-0500, manufactured by Denki Kagaku Kogyo Co., Ltd.) 50% by weight as resistance adjustment layer 11, polyether ester amide (IRGASTAT P18, Ciba A resin composition (volume resistivity: 2 × 10 8 Ωcm) consisting of 50% by weight (made by Specialty Chemicals) was coated by injection molding. Next, a ring-shaped gap holding member 12 made of a high-density polyethylene resin (Novatech PP HY540, manufactured by Nippon Polychem) is inserted and bonded to both ends, and the outer diameter (maximum diameter) of the gap holding member 12 is set to 12. 12 mm, the outer diameter of the resistance adjustment layer 11 was 12.00 mm, and finishing was performed at the same time to obtain the shape shown in FIG. Next, on the surface of the resistance adjusting layer 11, a mixture (surface resistance: 2 ×) composed of acrylic silicon resin (3000VH-P, manufactured by Kawakami Paint), isocyanate curing agent, and carbon black (35% by weight with respect to the total solid content). 109Ω) to form a surface layer having a film thickness of about 0.01 mm.
<Example 4>
Stainless steel core shaft (chargeable support 10: outer diameter 8 mm), ABS resin (Denka ABS GR-0500, manufactured by Denki Kagaku Kogyo Co., Ltd.) 50% by weight as a resistance adjustment layer, polyether ester amide (IRGASTAT P18, Ciba Specialty) A resin composition (volume resistivity: 2 × 10 8 Ωcm) consisting of 50% by weight (made by Chemicals) was coated by injection molding. Next, a ring-shaped gap holding member 12 made of a high-density polyethylene resin (Novatech PP HY540, manufactured by Nippon Polychem) is inserted and bonded to both ends, and the outer diameter (maximum diameter) of the gap holding member 12 is set to 12. 12 mm, the outer diameter of the resistance adjustment layer 11 was set to 12.00 mm, and finishing was performed at the same time to obtain the shape shown in FIG. Next, on the surface of the resistance adjusting layer, a mixture (surface resistance: 2 × 10 9 Ω) composed of acrylic silicon resin (3000 VH-P, manufactured by Kawakami Paint), an isocyanate curing agent, and carbon black (35% by weight with respect to the total solid content). ) To form a surface layer having a thickness of about 0.01 mm.
<Example 5>
Stainless steel core shaft (electrically resistant support 10: outer diameter 8 mm), ABS resin (Denka ABS GR-0500, manufactured by Denki Kagaku Kogyo Co., Ltd.) 50% by weight as resistance adjustment layer 11, polyether ester amide (IRGASTAT P18, Ciba A resin composition (volume resistivity: 2 × 10 8 Ωcm) consisting of 50% by weight (made by Specialty Chemicals) was coated by injection molding. Next, a ring-shaped gap holding member 12 made of a high-density polyethylene resin (Novatech PP HY540, manufactured by Nippon Polychem) is inserted and bonded to both ends, and the outer diameter (maximum diameter) of the gap holding member 12 is set to 12. Simultaneous finishing was performed to 12 mm and the outer diameter of the resistance adjustment layer 11 to 12.00 mm to obtain the shape shown in FIG. Next, on the surface of the resistance adjusting layer 11, a mixture (surface resistance: 2 ×) composed of acrylic silicon resin (3000VH-P, manufactured by Kawakami Paint), isocyanate curing agent, and carbon black (35% by weight with respect to the total solid content). 109Ω) to form a surface layer having a film thickness of about 0.01 mm.
<Example 6>
Stainless steel core shaft (conductive support 10: outer diameter 8 mm), ABS resin (Denka ABS GR-0500, manufactured by Denki Kagaku Kogyo Co., Ltd.) 50% by weight as resistance adjustment layer 11, polyether ester amide (IRGASTAT P18, Ciba A resin composition (volume resistivity: 2 × 10 8 Ωcm) consisting of 50% by weight (made by Specialty Chemicals) was coated by injection molding. Next, a ring-shaped gap holding member 12 made of high-density polyethylene resin (Novatech PP HY540, manufactured by Nippon Polychem) is inserted and bonded to both ends, and the outer diameter (maximum diameter) of the gap holding member 12 is set to 12. At the same time, the outer diameter of the resistance adjusting layer 11 was set to 12 mm, and the shape was shown in FIG. Next, on the surface of the resistance adjusting layer 11, a mixture (surface resistance: 2 ×) composed of acrylic silicon resin (3000VH-P, manufactured by Kawakami Paint), isocyanate curing agent, and carbon black (35% by weight with respect to the total solid content). 109Ω) to form a surface layer having a film thickness of about 0.01 mm.
<Comparative example 1>
A rubber composition (volume resistivity: 4 ×) in which 3 parts by weight of ammonium perchlorate is blended with 100 parts by weight of epichlorohydrin rubber (Epichromer CG, manufactured by Daiso Co., Ltd.) as a resistance adjusting layer on a core shaft (outer diameter 8 mm) made of stainless steel. 108 Ωcm) was coated through an extrusion molding and vulcanization process, and finished to an outer diameter of 12 mm by grinding. Next, on this surface, a mixture (surface resistance: 2 ×) composed of polyvinyl butyral resin (Denka Butyral 3000-K, manufactured by Denki Kagaku Kogyo Co., Ltd.), an isocyanate curing agent, and tin oxide (60% by weight with respect to the total solid content). 1010Ω) to form a surface layer having a thickness of 0.01 mm. Next, a tape-shaped member (Dai-tack PF025-H, manufactured by Dainippon Ink Co., Ltd.) having a thickness of 0.05 mm was pasted around both ends to form a charging roller.
<Comparative example 2>
An ion conductive high molecular compound (ROLEX AS) containing 50% by weight of ABS resin (GR-0500, manufactured by Denki Kagaku Kogyo) as a resistance adjustment layer on a core shaft (outer diameter 8 mm) made of stainless steel. -1720, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) A resin composition (volume resistivity: 2 × 10 8 Ωcm) comprising 50% by weight was coated by injection molding and finished to an outer diameter of 12.0 mm by cutting. Next, on the surface of the resistance adjustment layer, a mixture (surface resistance: 2 × 10 10 Ω) made of a fluororesin (Lumiflon LF-600, manufactured by Asahi Glass Co., Ltd.), an isocyanate curing agent, and tin oxide (60% by weight based on the total solid content). ) To form a surface layer having a thickness of about 0.01 mm. Next, a ring-shaped gap holding member (outer diameter 12.12 mm) made of stainless steel was inserted and bonded to both ends to form a charging roller.
<Comparative Example 3>
Stainless steel core shaft (outer diameter 8mm), resistance adjustment layer as ABS resin (Denka ABS GR-0500, manufactured by Denki Kagaku Kogyo Co., Ltd.) 50% by weight, polyether ester amide (IRGASTAT P18, manufactured by Ciba Specialty Chemicals) 50% % Resin volume (volume resistivity: 2 × 10 8 Ωcm) was coated by injection molding to an outer diameter of 12.0 mm. Next, on the surface of the resistance adjustment layer, a mixture (surface resistance: 2 × 10 10 Ω) made of a fluororesin (Lumiflon LF-600, manufactured by Asahi Glass Co., Ltd.), an isocyanate curing agent, and tin oxide (60% by weight based on the total solid content). ) To form a surface layer having a thickness of about 0.01 mm. Next, a ring-shaped gap holding member (outer diameter 12.12 mm) made of polyamide resin (Novamid 1010C2, manufactured by Mitsubishi Engineering Plastics) was inserted and bonded to both ends to form a charging roller.
<test>
The above-described charging roller was mounted on the image forming apparatus shown in FIG. 1, and the gap between the charging roller and the photosensitive member was measured.

次いで、印加する電圧をＤＣ＝−８００Ｖ、ＡＣ＝２４００Ｖpp(周波数＝2kHz)に設定し、６００，０００枚通紙してから帯電ローラと感光体との空隙の間隔、空隙保持部材の状態、及び印刷された画像について評価を行った。評価環境は２３℃、６０％RHである。
以上の評価結果を表１に示す。 Next, the applied voltage is set to DC = −800 V, AC = 2400 Vpp (frequency = 2 kHz), and after passing 600,000 sheets, the gap interval between the charging roller and the photosensitive member, the state of the gap holding member, The printed image was evaluated. The evaluation environment is 23 ° C. and 60% RH.
The above evaluation results are shown in Table 1.

表１より明らかなように、実施例１〜実施例６により形成された帯電ローラは全項目で良好な結果が得られたが、比較例１〜比較例４により形成された帯電ローラはでは不具合が見られた。 As is apparent from Table 1, the charging rollers formed in Examples 1 to 6 gave good results in all items, but the charging rollers formed in Comparative Examples 1 to 4 were defective. It was observed.

以上、本発明に係る導電性部材を帯電ローラとして用いた実施例を、図面を用いて説明したが、本発明に係る導電性部材は帯電ローラ等の帯電部材に限定されるものではなく、転写ローラ等の転写部材に使用するものであっても良い。導電性部材を転写部材として使用する場合であっても、同様の実施形態で使用することによって同様の効果を奏することが可能である。 As mentioned above, although the Example using the electroconductive member which concerns on this invention as a charging roller was demonstrated using drawing, the electroconductive member which concerns on this invention is not limited to charging members, such as a charging roller, A transfer It may be used for a transfer member such as a roller. Even when the conductive member is used as a transfer member, the same effect can be obtained by using the same in the same embodiment.

また、本発明に係る帯電性部材を用いた画像形成装置用のプロセスカートリッジや画像形成装置自体も同様の効果を奏することが可能である。 Further, the process cartridge for an image forming apparatus using the charging member according to the present invention and the image forming apparatus itself can achieve the same effect.

１画像形成装置
２帯電ローラ
４感光体ドラム
４ａ（感光体ドラムの）外表面
９プロセスカートリッジ
１０導電性支持体
１１抵抗調整層（電気抵抗調整層）
１２空隙保持手段
１２ａ（空隙保持手段の）の外表面
１２ｄ（空隙保持手段の）端部 DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Charging roller 4 Photosensitive drum 4a (Outside surface of photosensitive drum) 9 Process cartridge 10 Conductive support 11 Resistance adjusting layer (electric resistance adjusting layer)
12 Outer surface 12d (of the gap holding means) of the gap holding means 12a (of the gap holding means)

特開平７−９２５３７号公報JP-A-7-92537 特開２００６−１０６３４０号公報JP 2006-106340 A 実公平４−３５６号公報Japanese Utility Model Publication No. 4-356

Claims

An electrical resistance adjustment layer is provided on the peripheral surface of the intermediate portion excluding both ends of the conductive support that forms the shaft member,
At both ends of the conductive support, a gap adjusting member made of a material different from that of the electric resistance adjusting layer is attached with its one end face abutting and fixed to the end face of the electric resistance adjusting layer,
Thereafter, the gap is formed between the outer surface of the electric resistance adjusting layer and the outer surface of the photosensitive member in a state where the outer peripheral surfaces of the gap adjusting members are in contact with the outer peripheral surface of the photosensitive member. Removal processing from the other end of one gap adjustment member to the other end of the electrical resistance adjustment layer and the other air adjustment member,
At least one small diameter part which does not contact the outer surface of the said photoreceptor is formed in the side which touches the said electrical resistance adjustment layer of each said space | gap adjustment member, The manufacturing method of the electroconductive member characterized by the above-mentioned.

The method for producing a conductive member according to claim 1, wherein a surface layer that prevents adhesion of toner is formed on the surface of the electric resistance adjusting layer after the removal processing.