JP4673685B2 - Electrostatic latent image carrier, image forming method, image forming apparatus, and process cartridge - Google Patents

Description

  The present invention relates to an electrostatic latent image carrier (hereinafter also referred to as “photosensitive member” or “electrophotographic photosensitive member”) used for copying machines, electrostatic printing, printers, electrostatic recording, etc. The present invention relates to an image forming method using an electrostatic latent image carrier, an image forming apparatus, and a process cartridge.

  In an image forming apparatus such as a copying machine, a printer, or a facsimile using an electrophotographic method, writing light modulated by image data is irradiated onto a uniformly charged photoconductor to electrostatically apply it to the photoconductor. A latent image is formed, and a toner image is formed on the photosensitive member by supplying toner to the photosensitive member on which the electrostatic latent image has been formed by developing means. Next, after the toner image on the photoconductor is transferred to a recording medium (recording paper) by a transfer unit, the toner transferred onto the recording medium by a fixing unit is fixed by heating and pressing, and the toner remaining on the surface of the photoconductor is fixed. It is collected by scraping with a cleaning blade.

  In an image forming apparatus using such an electrophotographic system, an organic photoreceptor containing an organic photoconductive substance is most widely used as the photoreceptor. The organic photoreceptor is easy to develop a material corresponding to various exposure light sources from visible light to infrared light, can select a material free from environmental pollution, has a low manufacturing cost, etc. This is an advantage. However, the organophotoreceptor has low mechanical strength, and the photosensitive layer is worn away after long-term use. There is a problem that the process cannot be performed. In the image forming process, the friction of the photosensitive member is generated in all the contact portions of the photosensitive member and other image forming units such as a developing unit and a transfer unit.

For this reason, it has been studied to improve the life of the photoreceptor by reducing the wear of the photosensitive layer, and various proposals have been made.
For example, Patent Document 1 proposes using a colloidal silica-containing curable silicone resin as a surface protective layer of a photoreceptor. However, the surface layer of the colloidal silica-containing curable silicone resin has improved wear resistance, but the electrophotographic characteristics during repeated use are insufficient, and fog and image blur are likely to occur. It is insufficient for the durability required as a long-life photosensitive member.

  Patent Document 2 and Patent Document 3 propose a photoreceptor having a resin layer on the surface of which an organosilicon-modified hole transporting compound is bonded in a curable organosilicon polymer compound. However, the resin layer of these photoconductors is liable to generate image blur, and for practical use, it is necessary to suppress the occurrence of image blur by installing a mechanism such as a drum heater. And cost increase. In addition, the residual potential in the exposed area is not sufficiently reduced, and in a low potential development process in which an image is formed while suppressing the charging potential, a decrease in image density becomes a problem.

  Patent Document 4 proposes a method of curing a curable siloxane resin having a charge transporting group to a three-dimensional network structure. However, in the proposed method, cracks in the coating film, which may be caused by volume shrinkage, may occur. In particular, the above problem occurs in combination with a commercially available coating agent that is inexpensive and easy to handle. In addition, the residual potential of the exposed portion is thickness dependent, which causes a problem of image density reduction in the low potential development process. Further, when the content of the charge transporting property-imparting group is increased, the coating film strength is lowered and sufficient durability may not be obtained. Further, it may cause image blurring, and it is difficult to obtain an electrophotographic photosensitive member that can output a good image repeatedly for a long period of time at low cost.

  Accordingly, the electrostatic latent image carrier that is excellent in wear resistance and does not generate abnormal images even during repeated use, an image forming method using the electrostatic latent image carrier, and an image equipped with the electrostatic latent image carrier The forming apparatus and the process cartridge have not been obtained yet, and it is desired to provide them promptly.

Japanese Patent Laid-Open No. 6-118681 Japanese Patent Laid-Open No. 9-124943 JP-A-9-190004 JP 2000-171990 A

  An object of the present invention is to solve various problems in the prior art and achieve the following objects. That is, the present invention provides a highly durable electrostatic latent image carrier having high wear resistance and good electrophotographic characteristics and capable of forming a stable image for a long period of time, and the electrostatic latent image carrier. An object is to provide an image forming method, an image forming apparatus, and a process cartridge using a body.

ただし、前記構造式（１）中、Ａｒ^１及びＡｒ^２は、互いに同一であってもよいし、異なっていてもよく、アリール基を表し、該アリール基は更に置換基により置換されていてもよい。Ｒ^１は、アリール基、アルキル基、及びアルコキシ基のいずれかを表し、これらは更に置換基により置換されていてもよい。ｎは１〜４の整数であり、ｎが２以上の場合、前記Ｒ^１は、互いに同一であってもよいし、異なっていても構わない。
＜４＞ 保護層が、微粒子を含有する前記＜１＞から＜３＞のいずれかに記載の静電潜像担持体である。
＜５＞ 微粒子が、コロイダルシリカ、酸化チタン及び酸化アルミニウムから選択される少なくとも１種である前記＜４＞に記載の静電潜像担持体である。
＜６＞ 保護層の厚みが、１〜１５μｍである前記＜１＞から＜５＞のいずれかに記載の静電潜像担持体である。
＜７＞ 感光層が、単層型感光層である前記＜１＞から＜６＞のいずれかに記載の静電潜像担持体である。
＜８＞ 感光層が、支持体上に、少なくとも電荷発生層と、電荷輸送層とをこの順に有する積層型感光層である前記＜１＞から＜６＞のいずれかに記載の静電潜像担持体である。
＜９＞ 静電潜像担持体と、該静電潜像担持体上に静電潜像を形成する静電潜像形成手段と、前記静電潜像をトナーを用いて現像して可視像を形成する現像手段と、前記可視像を記録媒体に転写する転写手段と、前記記録媒体に転写された転写像を定着させる定着手段とを少なくとも有する画像形成装置であって、
前記静電潜像担持体が、前記＜１＞から＜８＞のいずれかに記載の静電潜像担持体であることを特徴とする画像形成装置である。
＜１０＞ 画像形成装置が、静電潜像担持体表面に当接し、該静電潜像担持体表面に残留するトナーを除去するクリーニング手段を有する前記＜９＞に記載の画像形成装置である。
＜１１＞ 静電潜像形成手段が、帯電器と、露光器とを有し、該帯電器が静電潜像担持体に接触乃至非接触状態で配置され、直流及び交流電圧を重畳印加することによって静電潜像担持体表面を帯電する前記＜９＞から＜１０＞のいずれかに記載の画像形成装置である。
＜１２＞ 帯電器が、静電潜像担持体にギャップを付与する手段によって非接触に近接配置された帯電ローラであり、該帯電ローラに直流並びに交流電圧を重畳印加することによって静電潜像担持体表面を帯電する前記＜１１＞に記載の画像形成装置である。
＜１３＞ 画像形成装置が、複数色のトナーを順次重ね合わせてカラー画像を形成する前記＜９＞から＜１２＞のいずれかに記載の画像形成装置である。
＜１４＞ 画像形成装置が、少なくとも静電潜像担持体、静電潜像形成手段、現像手段、及び転写手段を有する画像形成要素を複数備えたタンデム型である前記＜９＞から＜１３＞のいずれかに記載の画像形成装置である。
＜１５＞ 画像形成装置が、静電潜像担持体上に形成されたトナー像が一次転写される中間転写体と、該中間転写体上に担持されたトナー像を記録媒体に二次転写する転写手段とを備えてなり、複数色のトナー画像を中間転写体上に順次重ね合わせてカラー画像を形成し、該カラー画像を記録媒体上に一括で二次転写する前記＜９＞から＜１４＞のいずれかに記載の画像形成装置である。
＜１６＞ 静電潜像担持体上に静電潜像を形成する静電潜像形成工程と、前記静電潜像をトナーを用いて現像して可視像を形成する現像工程と、前記可視像を記録媒体に転写する転写工程と、前記記録媒体に転写された転写像を定着させる定着工程とを少なくとも含む画像形成方法であって、
前記静電潜像担持体が、前記＜１＞から＜８＞のいずれかに記載の静電潜像担持体であることを特徴とする画像形成方法である。
＜１７＞ 前記＜１＞から＜８＞のいずれかに記載の静電潜像担持体と、帯電手段、現像手段、及びクリーニング手段から選択される少なくとも１つの手段を一体に有することを特徴とするプロセスカートリッジである。 Means for solving the problems are as follows. That is,
<1> A support, and at least a photosensitive layer and a protective layer are provided in this order on the support, and the protective layer is formed by crosslinking an organosilicon compound having either a hydroxyl group or a hydrolyzable group. An electrostatic latent image carrier comprising: a curable siloxane resin; and a non-crosslinked charge transport material that is not crosslinked with the curable siloxane resin.
<2> The mass ratio between the curable siloxane resin and the non-crosslinked charge transporting substance (curable siloxane resin / non-crosslinked charge transporting substance) is 6/4 to 3/7. An electrostatic latent image carrier.
<3> The electrostatic latent image carrier according to any one of <1> to <2>, wherein the non-crosslinked charge transporting substance contains a compound represented by the following structural formula (1).

However, in the structural formula (1), Ar ¹ and Ar ² may be the same as or different from each other, and each represents an aryl group, and the aryl group may be further substituted with a substituent. Good. R ¹ represents any of an aryl group, an alkyl group, and an alkoxy group, and these may be further substituted with a substituent. n is an integer of 1 to 4, and when n is 2 or more, the R ¹ may be the same or different from each other.
<4> The electrostatic latent image carrier according to any one of <1> to <3>, wherein the protective layer contains fine particles.
<5> The electrostatic latent image carrier according to <4>, wherein the fine particles are at least one selected from colloidal silica, titanium oxide, and aluminum oxide.
<6> The electrostatic latent image carrier according to any one of <1> to <5>, wherein the protective layer has a thickness of 1 to 15 μm.
<7> The electrostatic latent image carrier according to any one of <1> to <6>, wherein the photosensitive layer is a single-layer type photosensitive layer.
<8> The electrostatic latent image according to any one of <1> to <6>, wherein the photosensitive layer is a laminated photosensitive layer having at least a charge generation layer and a charge transport layer in this order on a support. It is a carrier.
<9> An electrostatic latent image carrier, electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, and developing the electrostatic latent image with toner to make it visible An image forming apparatus having at least developing means for forming an image, transfer means for transferring the visible image to a recording medium, and fixing means for fixing the transferred image transferred to the recording medium,
The electrostatic latent image carrier is the electrostatic latent image carrier according to any one of <1> to <8>.
<10> The image forming apparatus according to <9>, wherein the image forming apparatus includes a cleaning unit that contacts the surface of the electrostatic latent image carrier and removes toner remaining on the surface of the electrostatic latent image carrier. .
<11> The electrostatic latent image forming means includes a charger and an exposure device, and the charger is disposed in contact or non-contact with the electrostatic latent image carrier, and applies a direct current and an alternating voltage in a superimposed manner. The image forming apparatus according to any one of <9> to <10>, wherein the surface of the electrostatic latent image carrier is charged by this.
<12> A charging roller is a charging roller that is disposed in a non-contact proximity by means for imparting a gap to the electrostatic latent image carrier, and an electrostatic latent image is formed by applying a direct current and an alternating voltage to the charging roller in a superimposed manner. The image forming apparatus according to <11>, wherein the surface of the carrier is charged.
<13> The image forming apparatus according to any one of <9> to <12>, wherein the image forming apparatus forms a color image by sequentially superposing a plurality of color toners.
<14> The <9> to <13>, wherein the image forming apparatus is a tandem type including a plurality of image forming elements each having at least an electrostatic latent image carrier, an electrostatic latent image forming unit, a developing unit, and a transfer unit. The image forming apparatus according to any one of the above.
<15> An image forming apparatus secondarily transfers an intermediate transfer body on which a toner image formed on an electrostatic latent image carrier is primarily transferred, and a toner image carried on the intermediate transfer body to a recording medium. <9> to <14, wherein a plurality of color toner images are sequentially superimposed on the intermediate transfer member to form a color image, and the color image is secondarily transferred collectively onto a recording medium. The image forming apparatus according to any one of the above.
<16> An electrostatic latent image forming step of forming an electrostatic latent image on the electrostatic latent image carrier, a developing step of developing the electrostatic latent image with toner to form a visible image, An image forming method comprising at least a transfer step of transferring a visible image to a recording medium and a fixing step of fixing the transfer image transferred to the recording medium,
The electrostatic latent image carrier is the electrostatic latent image carrier according to any one of <1> to <8>.
<17> The electrostatic latent image carrier according to any one of <1> to <8>, and at least one unit selected from a charging unit, a developing unit, and a cleaning unit are integrally provided. Process cartridge.

  The electrostatic latent image carrier of the present invention has a support and at least a photosensitive layer and a protective layer in this order on the support, and the protective layer has either a hydroxyl group or a hydrolyzable group. Since it contains a curable siloxane resin obtained by crosslinking an organosilicon compound and a non-crosslinked charge transport material that is not crosslinked with the curable siloxane resin, it has high wear resistance and good electrophotographic characteristics, and is long A highly durable electrostatic latent image carrier capable of performing stable image formation over a period of time can be provided.

  The image forming apparatus of the present invention includes an electrostatic latent image carrier, electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, and the electrostatic latent image using toner. A developing unit that develops a visible image by development; a transfer unit that transfers the visible image to a recording medium; and a fixing unit that fixes the transferred image transferred to the recording medium. Since the electrostatic latent image carrier is the electrostatic latent image carrier of the present invention, a good image can be stably formed over a long period of time.

  The image forming method of the present invention includes an electrostatic latent image forming step of forming an electrostatic latent image on an electrostatic latent image carrier, and developing the electrostatic latent image with toner to form a visible image. The electrostatic latent image carrier comprises at least a development step, a transfer step for transferring the visible image to a recording medium, and a fixing step for fixing the transferred image transferred to the recording medium. Therefore, a good image can be stably formed over a long period of time.

  The process cartridge of the present invention includes at least one of an electrostatic latent image forming unit, an exposure unit, a developing unit, a transfer unit, and a cleaning unit, and the electrostatic latent image carrier of the present invention. As a result, it is excellent in convenience and a good image can be stably formed over a long period of time.

  According to the present invention, the conventional problems can be solved, and the electrostatic latent image carrier that is excellent in wear resistance and does not generate an abnormal image even in repeated use, and an image using the electrostatic latent image carrier. A forming method, an image forming apparatus on which the electrostatic latent image carrier is mounted, and a process cartridge can be provided.

(Electrostatic latent image carrier)
The electrostatic latent image carrier of the present invention comprises a support, and at least a photosensitive layer and a protective layer in this order on the support, and further comprises other layers as necessary.

<Protective layer>
The protective layer includes a curable siloxane resin obtained by crosslinking an organosilicon compound having either a hydroxyl group or a hydrolyzable group, and a non-crosslinked charge transport material that is not crosslinked with the curable siloxane resin. And further contains other components as necessary.

  The fact that the protective layer contains a non-crosslinked charge transporting substance can be confirmed from the fact that the non-crosslinking charge transporting substance is extracted when the latent electrostatic image bearing member is immersed and extracted in tetrahydrofuran.

-Curable siloxane resin-
The curable siloxane resin is obtained by crosslinking an organic silicon compound having either a hydroxyl group or a hydrolyzable group, and further, if necessary, a catalyst, a crosslinking agent, an organosilica sol, a silane coupling agent, an acrylic polymer or the like. It includes coalescence.
The crosslinking is not particularly limited and may be appropriately selected depending on the purpose, but is preferably heat crosslinking.

Examples of the organosilicon compound having either a hydroxyl group or a hydrolyzable group include a compound having an alkoxysilyl group, a partial hydrolysis condensate of a compound having an alkoxysilyl group, or a mixture thereof.
Examples of the compound having an alkoxysilyl group include tetraalkoxysilanes such as tetraethoxysilane; alkyltrialkoxysilanes such as methyltriethoxysilane; aryltrialkoxysilanes such as phenyltriethoxysilane. In addition, those obtained by introducing an epoxy group, a methacryloyl group, or a vinyl group into these compounds can also be used.
The partially hydrolyzed condensate of the compound having an alkoxysilyl group can be produced by a known method in which a predetermined amount of water, a catalyst or the like is added to the compound having the alkoxysilyl group and reacted.

As the raw material of the curable siloxane resin, commercially available products can be used. Specifically, GR-COAT (manufactured by Daicel Chemical Industries), Glass Resin (manufactured by Owens Corning), heatless glass (Ohashi Chemical Industries). ), NSC (manufactured by Nippon Seika Co., Ltd.), glass stock solution GO150SX, GO200CL (manufactured by Fine Glass Technology), MKC silicate (manufactured by Mitsubishi Chemical) as a copolymer of an alkoxysilyl compound and an acrylic resin or a polyester resin. Silicate / acrylic varnish XP-1030-1 (manufactured by Dainippon Color Material Industries Co., Ltd.), and the like.
The resulting curable siloxane-based resin forms a very high-density three-dimensional cross-linked structure, and is known to significantly improve wear resistance. By using it as a binder resin for a protective layer, electrophotography A significant increase in the life of the photoreceptor can be achieved.

ただし、前記構造式（１）中、Ａｒ^１及びＡｒ^２は、互いに同一であってもよいし、異なっていてもよく、アリール基を表し、該アリール基は更に置換基により置換されていてもよい。Ｒ^１は、アリール基、アルキル基、及びアルコキシ基のいずれかを表し、これらは更に置換基により置換されていてもよい。ｎは１〜４の整数であり、ｎが２以上の場合、前記Ｒ^１は、互いに同一であってもよいし、異なっていても構わない。 -Non-crosslinked charge transport material-
As the non-crosslinked charge transporting substance that is not crosslinked with the curable siloxane resin, for example, the compound represented by the following structural formula (1) has good compatibility with the curable siloxane resin, and has electrophotographic characteristics. Also, it is preferably used because it is excellent.

However, in the structural formula (1), Ar ¹ and Ar ² may be the same as or different from each other, and each represents an aryl group, and the aryl group may be further substituted with a substituent. Good. R ¹ represents any of an aryl group, an alkyl group, and an alkoxy group, and these may be further substituted with a substituent. n is an integer of 1 to 4, and when n is 2 or more, the R ¹ may be the same or different from each other.

Examples of the aryl group include a condensed polycyclic hydrocarbon group, a non-condensed carbocyclic group, and a heterocyclic group.
The condensed polycyclic hydrocarbon group preferably has 18 or less carbon atoms forming a ring, for example, a pentanyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptaenyl group, a biphenylenyl group, an as-indacenyl group. , S-indacenyl group, fluorenyl group, acenaphthylenyl group, preadenyl group, acenaphthenyl group, phenalenyl group, phenanthryl group, anthryl group, fluoranthenyl group, acephenanthrenyl group, aceanthrylenyl group, triphenylyl group, pyrenyl group , A chrycenyl group, a naphthacenyl group, and the like.
Examples of the non-condensed carbocyclic group include monovalent groups of monocyclic hydrocarbon compounds such as benzene, diphenyl ether, polyethylene diphenyl ether, diphenyl thioether, diphenyl sulfone; biphenyl, polyphenyl, diphenylalkane, diphenylalkene, diphenylalkyne , Monovalent groups of non-condensed polycyclic hydrocarbon compounds such as triphenylmethane, distyrylbenzene, 1,1-diphenylcycloalkane, polyphenylalkane, and polyphenylalkene; ring assembly carbonization such as 9,9-diphenylfluorene And monovalent groups of hydrogen compounds.
Examples of the heterocyclic group include monovalent groups such as carbazole, dibenzofuran, dibenzothiophene, oxadiazole, and thiadiazole.

ただし、前記構造式中、Ｒ^２及びＲ^３は、各々独立に水素原子、置換又は無置換のアルキル基、又はアリール基を表す。
前記アルキル基としては、例えば、メチル基、エチル基、プロピル基、ブチル基、などが挙げられる。
前記アリール基としては、例えば、フェニル基、ビフェニル基又はナフチル基が挙げられ、これらは炭素数１〜４のアルコキシ基、炭素数１〜４のアルキル基又はハロゲン原子を置換基として含有してもよい。なお、Ｒ^２及びＲ^３は、互いに連結して環を形成してもよい。
具体的には、アミノ基、ジエチルアミノ基、Ｎ−メチル−Ｎ−フェニルアミノ基、Ｎ，Ｎ−ジフェニルアミノ基、Ｎ，Ｎ−ジ（トリール）アミノ基、ジベンジルアミノ基、ピペリジノ基、モルホリノ基、ピロリジノ基等が挙げられる。
（６）置換又は無置換のスチリル基、置換又は無置換のβ−フェニルスチリル基、ジフェニルアミノフェニル基、ジトリルアミノフェニル基等である。
（７）下記構造式で表されるアルキレン、ビニレンで連結された置換又は無置換のアリール基である。

ただし、前記構造式中、Ｒ^４は、水素原子、置換又は無置換のアルキル基、アリール基アリール基としては、フェニル基、ビフェニル基、トリフェニルアミノ基、ジトリルアミノフェニル基等が挙げられる。ｉは２〜４、ｋは１又は２を表す。
前記置換アルキル基としては、アルキル基にフッ素原子、水酸基、シアノ基、アルコキシ基、フェニル基又はハロゲン原子、更にアルキル基やアルコキシ基で置換されたフェニル基等を表す。具体的にはトリフルオロメチル基、２−ヒドロキエチル基、２−エトキシエチル基、２−シアノエチル基、２−メトキシエチル基、ベンジル基、４−クロロベンジル基、４−メチルベンジル基、４−フェニルベンジル基、テトラヒドロフルフリル基、等が挙げられる。 The aryl group may be further substituted with a substituent as shown below, for example.
(1) A halogen atom, a cyano group, a nitro group, etc. are mentioned.
(2) Trifluoromethyl group, 2-hydroxyethyl group, 2-ethoxyethyl group, 2-cyanoethyl group, 2-methoxyethyl group, benzyl group, 4-chlorobenzyl group, 4-methylbenzyl group, 4-phenylbenzyl Groups and the like.
(3) Examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, a t-butoxy group, an n-butoxy group, an s-butoxy group, an i-butoxy group, and 2-hydroxyethoxy. Group, benzyloxy group, trifluoromethoxy group and the like.
(4) An aryloxy group, and examples of the aryl group include a phenyl group and a naphthyl group. This may contain a C1-C4 alkoxy group, a C1-C4 alkyl group, or a halogen atom as a substituent. Specific examples include a phenoxy group, a 1-naphthyloxy group, a 2-naphthyloxy group, a 4-methoxyphenoxy group, and a 4-methylphenoxy group.
(5) A substituent represented by the following structural formula.

However, in said structural formula, R < ² > and R < ³ > represents a hydrogen atom, a substituted or unsubstituted alkyl group, or an aryl group each independently.
Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group.
As said aryl group, a phenyl group, a biphenyl group, or a naphthyl group is mentioned, for example, These contain a C1-C4 alkoxy group, a C1-C4 alkyl group, or a halogen atom as a substituent. Good. R ² and R ³ may be connected to each other to form a ring.
Specifically, amino group, diethylamino group, N-methyl-N-phenylamino group, N, N-diphenylamino group, N, N-di (tolyl) amino group, dibenzylamino group, piperidino group, morpholino group And pyrrolidino group.
(6) A substituted or unsubstituted styryl group, a substituted or unsubstituted β-phenylstyryl group, a diphenylaminophenyl group, a ditolylaminophenyl group, and the like.
(7) A substituted or unsubstituted aryl group linked by alkylene or vinylene represented by the following structural formula.

However, in the structural formula, R ⁴ includes a hydrogen atom, a substituted or unsubstituted alkyl group, and an aryl group aryl group such as a phenyl group, a biphenyl group, a triphenylamino group, and a ditolylaminophenyl group. i represents 2 to 4, and k represents 1 or 2.
The substituted alkyl group represents a fluorine atom, a hydroxyl group, a cyano group, an alkoxy group, a phenyl group or a halogen atom, and a phenyl group substituted with an alkyl group or an alkoxy group. Specifically, trifluoromethyl group, 2-hydroxyethyl group, 2-ethoxyethyl group, 2-cyanoethyl group, 2-methoxyethyl group, benzyl group, 4-chlorobenzyl group, 4-methylbenzyl group, 4-phenyl A benzyl group, a tetrahydrofurfuryl group, etc. are mentioned.

Specifically, the non-crosslinked charge transporting substance represented by the structural formula (1) is preferably a compound represented by the following structural formula.

The mixing mass ratio (curable siloxane resin / non-crosslinked charge transporting substance) of the curable siloxane resin and the non-crosslinked charge transporting substance in the protective layer is preferably 6/4 to 3/7. Thereby, it is thought that it has sufficient charge transfer characteristic, without raise | generating the crosslinking reaction accompanied by volume shrinkage. In addition, the non-crosslinked charge transporting substance has poor compatibility with the curable siloxane resin, and the coating film may become cloudy. However, the non-crosslinked charge transporting substance may be used in combination with a curable siloxane resin, for example, the above-described commercially available coating agent. In some cases, it may be improved by selecting a solvent, a condition for heat-curing, and the like. For example, a mixed solvent in which an alcohol solvent in which a curable siloxane resin is soluble and a ketone solvent in which a non-crosslinked charge transporting substance is soluble is mixed in an appropriate ratio, or a heating temperature and time are suitably selected. There is a way. By using these means, even in the case of heat curing in a mixed system in which the non-crosslinked charge transporting substance is mixed with a curable siloxane resin, good coating quality can be obtained without causing cracks or cloudiness of the coating film. Obtainable.
When the content of the non-crosslinked charge transporting substance is less than 6/4, the potential of the exposed portion is not sufficiently lowered, and particularly in a low temperature environment, the cause of abnormal images such as a reduction in image density. It may become. On the other hand, when the content of the non-crosslinked charge transporting substance is more than 3/7, a decrease in wear resistance, which is considered to be caused by insufficient curing of the curable siloxane resin, is observed. Sometimes.

In addition to the curable siloxane resin and the non-crosslinked charge transport material, fine particles are preferably added to the protective layer for the purpose of further improving the wear resistance.
Examples of the fine particles include organic fine particles and inorganic fine particles.
Examples of the organic fine particles include fluorine resin fine particles such as polytetrafluoroethylene; silicon resin fine particles, guanamine formaldehyde resin fine particles, and the like.
Examples of the inorganic fine particles include metal powders such as copper, tin, aluminum, and indium; colloidal silica, tin oxide, zinc oxide, titanium oxide, aluminum oxide, indium oxide, antimony oxide, bismuth oxide, calcium oxide, and antimony. -Metal oxides such as tin oxide doped with tin and indium oxide doped with tin; metal fluorides such as tin fluoride, calcium fluoride and aluminum fluoride; potassium titanate, boron nitride and the like. These may be used individually by 1 type and may use 2 or more types together.
Among these, in order to improve wear resistance, inorganic fine particles are preferable, and colloidal silica, titanium oxide, and aluminum oxide, which have a good balance with electrophotographic characteristics, are particularly preferable.
The content of the fine particles in the protective layer is preferably 0.1 to 30% by mass.

Various additives may be added to the protective layer for the purpose of improving adhesiveness, smoothness, and chemical stability to the extent that does not inhibit the curing of the siloxane resin.
The protective layer is formed on the photosensitive layer using a conventional coating method such as dip coating, spray coating, blade coating, knife coating, etc., using a protective layer forming coating solution containing each of the above components. Is done. In particular, dip coating and spray coating are advantageous in terms of mass productivity and coating film quality.
Examples of the organic solvent used in the protective layer-forming coating solution include acetone, methyl ethyl ketone, methyl isopropyl ketone, cyclohexanone, benzene, toluene, xylene, chloroform, dichloromethane, dichloroethane, dichloropropane, trichloroethane, trichloroethylene, tetrachloroethane, and tetrahydrofuran. , Dioxolane, dioxane, methanol, ethanol, isopropyl alcohol, butanol, ethyl acetate, butyl acetate, dimethyl sulfoxide, methyl cellosolve, ethyl cellosolve, propyl cellosolve and the like. These may be used individually by 1 type and may use 2 or more types together.

  1-15 micrometers is preferable and, as for the thickness of the said protective layer, 1-10 micrometers is more preferable. If the thickness is less than 1 μm, the wear resistance may be insufficient.

In the first embodiment, the electrostatic latent image carrier comprises a single-layer type photosensitive layer on a support, and a protective layer provided on the single-layer type photosensitive layer, and if necessary, an intermediate layer, It has other layers.
In the second embodiment, the latent electrostatic image bearing member includes a support, a stacked photosensitive layer having at least a charge generation layer and a charge transport layer in this order on the support, and the stacked photosensitive layer. A protective layer is provided on the top, and a protective layer and other layers are provided as necessary. In the second embodiment, the charge generation layer and the charge transport layer may be laminated in reverse.

  Here, FIG. 1 is a schematic cross-sectional view of the electrostatic latent image carrier of the present invention, in which a photosensitive layer 202 is provided on a support 201. 2, FIG. 3, FIG. 4, and FIG. 5 show examples of the layer structure of another electrostatic latent image carrier of the present invention. FIG. 2 shows that the photosensitive layer is a charge generation layer (CGL). ) 203 and a charge transport layer (CTL) 204. In FIG. 3, an undercoat layer 205 is inserted between a support 201, a charge generation layer (CGL) 203 of a function separation type photosensitive layer, and a charge transport layer (CTL) 204. FIG. 4 shows a type in which a protective layer 206 is laminated on the charge transport layer 204. FIG. 5 shows a type in which an intermediate layer 207 is provided between the undercoat layer 205 and the charge generation layer 203. The electrostatic latent image carrier of the present invention may have any combination of the above other layers and photosensitive layer types as long as it has at least the photosensitive layer 202 on the support 201. .

<Multi-layer type photosensitive layer>
As described above, the multilayer photosensitive layer includes at least a charge generation layer and a charge transport layer in this order, and further includes other layers as necessary.

-Charge generation layer-
The charge generation layer includes at least a charge generation material, and includes a binder resin and, if necessary, other components.

  There is no restriction | limiting in particular as said charge generation substance, Although it can select suitably according to the objective, Either an inorganic material and an organic material can be used.

  The inorganic material is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include crystalline selenium, amorphous-selenium, selenium-tellurium, selenium-tellurium-halogen, and selenium-arsenic compounds. It is done.

  The organic material is not particularly limited and may be appropriately selected from known materials according to the purpose. For example, phthalocyanine pigments such as metal phthalocyanine and metal-free phthalocyanine, azulenium salt pigments, squaric acid Methine pigment, azo pigment having carbazole skeleton, azo pigment having triphenylamine skeleton, azo pigment having diphenylamine skeleton, azo pigment having dibenzothiophene skeleton, azo pigment having fluorenone skeleton, azo pigment having oxadiazole skeleton, An azo pigment having a bis-stilbene skeleton, an azo pigment having a distyryl oxadiazole skeleton, an azo pigment having a distyryl carbazole skeleton, a perylene pigment, an anthraquinone or polycyclic quinone pigment, a quinoneimine pigment, diphenylmethane or Phenyl pigments, benzoquinone or naphthoquinone pigments, cyanine and azomethine pigments, indigoid pigments, bisbenzimidazole pigments, and the like. These may be used individually by 1 type and may use 2 or more types together.

  There is no restriction | limiting in particular as said binder resin, According to the objective, it can select suitably, For example, a polyamide resin, a polyurethane resin, an epoxy resin, a polyketone resin, a polycarbonate resin, a silicone resin, an acrylic resin, a polyvinyl butyral resin, polyvinyl Formal resin, polyvinyl ketone resin, polystyrene resin, poly-N-vinyl carbazole resin, polyacrylamide resin, and the like can be given. These may be used individually by 1 type and may use 2 or more types together.

  If necessary, a charge transport material may be added. In addition to the binder resin described above, a polymer charge transport material can be added as the binder resin for the charge generation layer.

As a method for forming the charge generation layer, a vacuum thin film production method and a casting method from a solution dispersion system can be mentioned.
Examples of the former method include a glow discharge polymerization method, a vacuum deposition method, a CVD method, a sputtering method, a reactive sputtering method, an ion plating method, and an accelerated ion injection method. This vacuum thin film manufacturing method can satisfactorily form the inorganic material or organic material described above.
In order to form the charge generation layer by the latter casting method, it is possible to use a charge generation layer coating solution and a conventional method such as a dip coating method, a spray coating method, or a bead coating method.

Examples of the organic solvent used in the charge generation layer coating solution include acetone, methyl ethyl ketone, methyl isopropyl ketone, cyclohexanone, benzene, toluene, xylene, chloroform, dichloromethane, dichloroethane, dichloropropane, trichloroethane, trichloroethylene, tetrachloroethane, and tetrahydrofuran. , Dioxolane, dioxane, methanol, ethanol, isopropyl alcohol, butanol, ethyl acetate, butyl acetate, dimethyl sulfoxide, methyl cellosolve, ethyl cellosolve, propyl cellosolve and the like. These may be used individually by 1 type and may use 2 or more types together.
Among these, tetrahydrofuran, methyl ethyl ketone, dichloromethane, methanol, and ethanol having a boiling point of 40 ° C. to 80 ° C. are particularly preferable because they can be easily dried after coating.
The charge generation layer coating solution is produced by dispersing and dissolving the charge generation material and a binder resin in the organic solvent. Examples of the method for dispersing the organic pigment in the organic solvent include a dispersion method using a dispersion medium such as a ball mill, a bead mill, a sand mill, and a vibration mill, and a high-speed liquid collision dispersion method.

  Depending on the thickness of the charge generation layer, the electrophotographic characteristics, particularly the photosensitivity, change. Generally, the thicker the thickness, the higher the photosensitivity. Therefore, the thickness of the charge generation layer is preferably set in a suitable range according to the required specifications of the image forming apparatus. In order to obtain the sensitivity required as an electrophotographic photosensitive member, it is usually 0. 01-5 micrometers is preferable and 0.05-2 micrometers is more preferable.

-Charge transport layer-
The charge transport layer is a layer intended to hold a charged charge and to couple the charge generated and separated in the charge generation layer by exposure to the charged charge that has been held. In order to achieve the purpose of holding the charged charge, it is required that the electric resistance is high. Further, in order to achieve the purpose of obtaining a high surface potential with the charged charge that has been held, it is required that the dielectric constant is small and the charge mobility is good.

  The charge transport layer includes at least a charge transport material, and includes a binder resin and, if necessary, other components.

Examples of the charge transport material include a hole transport material, an electron transport material, and a polymer charge transport material.
Examples of the electron transporting material (electron-accepting material) include chloranil, bromoanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro. -9-fluorenone, 2,4,5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1,2-b] thiophene-4-one, 1,3,7-trinitrodibenzothiophene-5,5-dioxide, and the like. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the hole transport material (electron donating material) include oxazole derivatives, oxadiazole derivatives, imidazole derivatives, triphenylamine derivatives, 9- (p-diethylaminostyrylanthracene), 1,1-bis- (4 -Dibenzylaminophenyl) propane, styrylanthracene, styrylpyrazoline, phenylhydrazones, α-phenylstilbene derivatives, thiazole derivatives, triazole derivatives, phenazine derivatives, acridine derivatives, benzofuran derivatives, benzimidazole derivatives, thiophene derivatives, etc. It is done. These may be used individually by 1 type and may use 2 or more types together.

Examples of the polymer charge transport material include those having the following structure.
Examples of (a) a polymer having a carbazole ring include, for example, poly-N-vinylcarbazole, JP-A-50-82056, JP-A-54-9632, JP-A-54-11737, JP-A-5-11737. Examples thereof include compounds described in JP-A-4-175337, JP-A-4-183719, and JP-A-6-234841.
(B) Examples of the polymer having a hydrazone structure include, for example, JP-A-57-78402, JP-A-61-20953, JP-A-61-296358, JP-A-1-134456, Compounds described in Kaihei 1-179164, JP-A-3-180851, JP-A-3-180852, JP-A-3-50555, JP-A-5-310904, and JP-A-6-234840 Etc. are exemplified.
(C) Examples of the polysilylene polymer include, for example, JP-A-63-285552, JP-A-1-88461, JP-A-4-264130, JP-A-4-264131, and JP-A-4-264132. Examples thereof include compounds described in JP-A-4-264133 and JP-A-4-289867.
(D) As a polymer having a triarylamine structure, for example, N, N-bis (4-methylphenyl) -4-aminopolystyrene, JP-A-1-134457, JP-A-2-282264, Examples thereof include compounds described in Kaihei 2-304456, JP-A-4-133605, JP-A-4-133066, JP-A-5-40350, and JP-A-5-202135.
(E) As other polymers, for example, a formaldehyde condensation polymer of nitropyrene, JP-A-51-73888, JP-A-56-15049, JP-A-6-234363, JP-A-6-234837 And the compounds described in Japanese Patent Publication No.

  In addition to the above, the polymer charge transporting material includes, for example, a polycarbonate resin having a triarylamine structure, a polyurethane resin having a triarylamine structure, a polyester resin having a triarylamine structure, and a triarylamine structure. And a polyether resin. Examples of the polymer charge transporting material include JP-A 64-1728, JP-A 64-13061, JP-A 64-19049, JP-A-4-11627, JP-A 4-116627. JP 2225014, JP 4-230767, JP 4-320420, JP 5-232727, JP 7-56374, JP 9-127713, JP 9-222740. And compounds described in JP-A-9-265197, JP-A-9-211877, JP-A-9-30495, and the like.

  Examples of the polymer having an electron donating group include not only the above-mentioned polymer but also a copolymer with a known monomer, a block polymer, a graft polymer, a star polymer, It is also possible to use a crosslinked polymer having an electron donating group as disclosed in JP-A-109406.

Examples of the binder resin include polycarbonate resin, polyester resin, methacrylic resin, acrylic resin, polyethylene resin, polyvinyl chloride resin, polyvinyl acetate resin, polystyrene resin, phenol resin, epoxy resin, polyurethane resin, polyvinylidene chloride resin, Alkyd resins, silicone resins, polyvinyl carbazole resins, polyvinyl butyral resins, polyvinyl formal resins, polyacrylate resins, polyacrylamide resins, phenoxy resins, and the like are used. These may be used individually by 1 type and may use 2 or more types together.
The charge transport layer can also contain a copolymer of a crosslinkable binder resin and a crosslinkable charge transport material.

  The charge transport layer can be formed by dissolving or dispersing these charge transport materials and a binder resin in an appropriate solvent, and applying and drying them. In addition to the charge transport material and the binder resin, an appropriate amount of additives such as a plasticizer, an antioxidant, and a leveling agent may be added to the charge transport layer as necessary.

  The thickness of the charge transport layer is preferably 5 to 100 μm, and in recent years, the charge transport layer has been made thinner to meet the demand for higher image quality. In order to achieve higher image quality of 1200 dpi or more, 5-30 micrometers is more preferable.

<Single layer type photosensitive layer>
The single-layer type photosensitive layer includes a charge generation material, a charge transport material, and a binder resin, and further includes other components as necessary.
As the charge generation material, the charge transport material, and the binder resin, the same materials as those of the multilayer photosensitive layer can be used.

  When a single-layer type photosensitive layer is provided by a casting method, in many cases, such a single-layer type photosensitive layer is prepared by dissolving or dispersing a charge generating substance, a low molecular weight molecule, and a polymer charge transporting substance in an appropriate solvent, It can be formed by drying. The single-layer type photosensitive layer may further contain a plasticizer and a binder resin as necessary. As the binder resin, the same binder resin as that of the charge transport layer can be used. In addition, the same binder resin as that of the charge generation layer may be mixed and used.

  The thickness of the single-layer type photosensitive layer is preferably 5 to 100 μm, and more preferably 5 to 50 μm. When the thickness is less than 5 μm, the chargeability may be lowered, and when it exceeds 100 μm, the sensitivity may be lowered.

-Support-
The support is not particularly limited as long as it has conductivity, and can be appropriately selected depending on the purpose. For example, a conductor or an insulator subjected to a conductive treatment is suitable, for example, Al, Metals such as Ni, Fe, Cu, Au, or alloys thereof; metals such as Al, Ag, Au, etc. on conductive substrates such as polyester, polycarbonate, polyimide, glass, etc., or conductivity such as In ₂ O ₃ , SnO ₂ A thin film of material; carbon black, graphite, metal powder such as Al, Cu, Ni, etc., conductive glass powder, etc. are uniformly dispersed in the resin, and the resin base is made conductive by conducting the resin. Paper.

  The shape and size of the support are not particularly limited, and any of a plate shape, a drum shape, and a belt shape can be used. When a belt-like support is used, a driving roller and a driven roller are provided inside. While it is necessary to provide such a device, the device is complicated or large, but there is an advantage that the degree of freedom in layout is increased. On the other hand, a drum-like support is preferable because of its high rigidity.

  An undercoat layer may be provided between the support and the photosensitive layer as necessary. The undercoat layer is provided for the purpose of improving adhesiveness, preventing moire, improving the coatability of the upper layer, and reducing residual potential.

The undercoat layer generally comprises a resin as a main component, but these resins are resins having a high resistance to dissolution with respect to a general organic solvent in consideration of applying a photosensitive layer thereon using a solvent. It is preferable that
Examples of the resin include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon, polyurethane, melamine resin, alkyd-melamine resin, and epoxy resin. Examples thereof include a curable resin that forms a three-dimensional network structure.
Further, fine powders such as metal oxides exemplified by titanium oxide, silica, alumina, zirconium oxide, tin oxide, indium oxide and the like, or metal sulfides and metal nitrides may be added. These undercoat layers can be formed by a common coating method using an appropriate solvent.

As the undercoat layer, a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like is used. For example, a metal oxide layer formed by a sol-gel method or the like, Al ₂ O ₃ is used as an anode. Those provided by oxidation, organic substances such as polyparaxylylene (parylene), and those provided with inorganic substances such as SnO ₂ , TiO ₂ , ITO, and CeO ₂ by a vacuum thin film manufacturing method can also be used.
There is no restriction | limiting in particular in the thickness of the said undercoat layer, According to the objective, it can select suitably, 0.1-10 micrometers is preferable and 1-5 micrometers is more preferable.

In the latent electrostatic image bearing member (photoreceptor), an intermediate layer may be provided on the support, if necessary, in order to improve adhesion and static charge blocking. The intermediate layer generally contains a resin as a main component. However, considering that the photosensitive layer is coated with a solvent on these resins, it is desirable that the resin be a resin having a high solvent resistance with respect to a general organic solvent. .
Examples of the resin include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon, polyurethane resins, melamine resins, phenol resins, alkyd-melamine resins, Examples thereof include curable resins that form a three-dimensional network structure such as epoxy resins.

(Image forming method and image forming apparatus)
The image forming apparatus of the present invention includes at least an electrostatic latent image carrier, an electrostatic latent image forming unit, a developing unit, a transfer unit, and a fixing unit, and further appropriately selected as necessary. It has other means, for example, static elimination means, cleaning means, recycling means, control means and the like.
The image forming method of the present invention includes at least an electrostatic latent image forming step, a developing step, a transfer step, and a fixing step, and other steps appropriately selected as necessary, for example, a static elimination step, a cleaning step. , Including recycling process, control process, etc.

  The image forming method of the present invention can be preferably carried out by the image forming apparatus of the present invention, the electrostatic latent image forming step can be performed by the electrostatic latent image forming means, and the developing step is the developing The transfer step can be performed by the transfer unit, the fixing step can be performed by the fixing unit, and the other steps can be performed by the other unit.

-Electrostatic latent image forming step and electrostatic latent image forming means-
The electrostatic latent image forming step is a step of forming an electrostatic latent image on the electrostatic latent image carrier.
The electrostatic latent image carrier of the present invention is used as the electrostatic latent image carrier.

The formation of the electrostatic latent image can be performed, for example, by uniformly charging the surface of the electrostatic latent image carrier and then performing imagewise exposure, and is performed by the electrostatic latent image forming unit. be able to.
The electrostatic latent image forming means includes, for example, at least a charger that uniformly charges the surface of the electrostatic latent image carrier and an exposure device that exposes the surface of the electrostatic latent image carrier imagewise. Prepare.

The charging can be performed, for example, by applying a voltage to the surface of the electrostatic latent image carrier using the charger.
The charger is not particularly limited and can be appropriately selected according to the purpose. And non-contact chargers utilizing corona discharge such as corotrons and corotrons.

The shape of the charging member may be any form such as a magnetic brush or a fur brush in addition to a roller, and can be selected according to the specifications and form of the electrophotographic apparatus. When the magnetic brush is used, the magnetic brush is made up of various ferrite particles such as Zn-Cu ferrite as a charging member, a nonmagnetic conductive sleeve for supporting the ferrite member, and a magnet roll included in the nonmagnetic conductive sleeve. Or when using a brush, for example, as the material of the fur brush, a fur treated with carbon, copper sulfide, metal or metal oxide is used, and this is wound or attached to a metal or other conductive core. To make a charger.
The charger is not limited to the contact charger as described above. However, since an image forming apparatus in which ozone generated from the charger is reduced is obtained, a contact charger is used. Is preferred.
It is preferable that the charger is disposed in contact or non-contact with the electrostatic latent image carrier and charges the surface of the electrostatic latent image carrier by applying a direct current and an alternating voltage.
Further, the charging device is a charging roller disposed in close proximity to the electrostatic latent image carrier via a gap tape, and the electrostatic latent image carrier is applied by applying a direct current and an alternating voltage to the charging roller. Those that charge the surface are preferred.
The exposure can be performed, for example, by exposing the surface of the latent electrostatic image bearing member imagewise using the exposure device.
The exposure device is not particularly limited as long as it can expose the surface of the electrostatic latent image carrier charged by the charger so as to form an image to be formed, and is appropriately selected according to the purpose. For example, various exposure devices such as a copying optical system, a rod lens array system, a laser optical system, and a liquid crystal shutter optical system can be used.
In the present invention, a back light system in which imagewise exposure is performed from the back side of the electrostatic latent image carrier may be employed.

-Development process and development means-
The developing step is a step of developing the electrostatic latent image using the toner or the developer to form a visible image.
The visible image can be formed, for example, by developing the electrostatic latent image using the toner or the developer, and can be performed by the developing unit.
The developing means is not particularly limited as long as it can be developed using, for example, the toner or the developer, and can be appropriately selected from known ones. For example, the toner or developer is accommodated. Preferred examples include those having at least a developing unit capable of bringing the toner or developer into contact or non-contact with the electrostatic latent image.

  The developing unit may be a dry developing type, a wet developing type, a single color developing unit, or a multi-color developing unit. For example, a toner having a stirrer for charging the toner or the developer by frictional stirring and a rotatable magnet roller is preferable.

  In the developing device, for example, the toner and the carrier are mixed and agitated, and the toner is charged by friction at that time, and held on the surface of the rotating magnet roller in a raised state to form a magnetic brush. . Since the magnet roller is disposed in the vicinity of the electrostatic latent image carrier (photoconductor), a part of the toner constituting the magnetic brush formed on the surface of the magnet roller is electrically attracted. It moves to the surface of the electrostatic latent image carrier (photoconductor) by force. As a result, the electrostatic latent image is developed with the toner, and a visible image is formed with the toner on the surface of the electrostatic latent image carrier (photoconductor).

  The developer accommodated in the developing device may be a one-component developer or a two-component developer.

-Transfer process and transfer means-
The transfer step is a step of transferring the visible image onto a recording medium. After the primary transfer of the visible image onto the intermediate transfer member using an intermediate transfer member, the visible image is transferred onto the recording medium. A primary transfer step of forming a composite transfer image by transferring a visible image onto an intermediate transfer body using two or more colors, preferably full color toner as the toner, and a composite transfer image; A mode including a secondary transfer step of transferring the transfer image onto the recording medium is more preferable.
The transfer can be performed, for example, by charging the latent electrostatic image bearing member (photoconductor) of the visible image using a transfer charger, and can be performed by the transfer unit. The transfer means includes a primary transfer means for transferring a visible image onto an intermediate transfer member to form a composite transfer image, and a secondary transfer means for transferring the composite transfer image onto a recording medium. Embodiments are preferred.
The intermediate transfer member is not particularly limited and may be appropriately selected from known transfer members according to the purpose. For example, a transfer belt and the like are preferable.

The static friction coefficient of the intermediate transfer member is preferably 0.1 to 0.6, and more preferably 0.3 to 0.5.
The volume resistance of the intermediate transfer member is preferably several Ωcm or more and 10 ³ Ωcm or less. By setting the volume resistance to several Ωcm or more and 10 ³ Ωcm or less, the intermediate transfer member itself is prevented from being charged, and the charge imparted by the charge imparting means hardly remains on the intermediate transfer member. Transfer unevenness can be prevented. Further, it is possible to easily apply a transfer bias at the time of secondary transfer.

  The material of the intermediate transfer member is not particularly limited and can be appropriately selected from known materials according to the purpose. For example, (1) a material having a high Young's modulus (tensile elastic modulus) is used as a single-layer belt. PC (polycarbonate), PVDF (polyvinylidene fluoride), PAT (polyalkylene terephthalate), PC (polycarbonate) / PAT (polyalkylene terephthalate) blend material, ETFE (ethylene tetrafluoroethylene copolymer) / PC blend material, ETFE / PAT blend material, PC / PAT blend material, carbon black-dispersed thermosetting polyimide, and the like. These single-layer belts having a high Young's modulus have the advantage that the amount of deformation with respect to stress during image formation is small, and registration is not likely to occur particularly during color image formation. (2) A belt having a two- to three-layer structure in which a belt having a high Young's modulus is used as a base layer and a surface layer or an intermediate layer is provided on the outer periphery of the belt. Therefore, the line image has a performance capable of preventing the line image from being lost. (3) Belts having a relatively low Young's modulus using rubber and elastomer, and these belts have an advantage that line images are hardly lost due to their softness. In addition, the belt width is made larger than that of the drive roll and the tension roll, and the elasticity of the belt ear protruding from the roll is used to prevent meandering, so that a low cost can be realized without the need for ribs or meandering prevention devices. .

For the intermediate transfer belt, fluorine resin, polycarbonate resin, polyimide resin and the like have been conventionally used. However, in recent years, an elastic belt in which the entire belt layer or a part of the belt is used as an elastic member has been used. . The transfer of a color image using a resin belt has the following problems.
A color image is usually formed with four colored toners. On one color image, toner layers of 1 to 4 layers are formed. The toner layer receives pressure by passing through the primary transfer (transfer from the photoreceptor to the intermediate transfer belt) and the secondary transfer (transfer from the intermediate transfer belt to the sheet), and the cohesive force between the toners increases. When the cohesive force between the toners is increased, the phenomenon of missing characters in characters and missing images in solid images tends to occur. Since the resin belt has high hardness and does not deform according to the toner layer, it is easy to compress the toner layer, and the character dropout phenomenon tends to occur.
Recently, there is an increasing demand for forming full-color images on various papers, for example, Japanese paper, intentionally irregularities, and forming images on paper. However, a paper with poor smoothness is liable to generate toner and voids at the time of transfer, and transfer loss is likely to occur. If the transfer pressure at the secondary transfer portion is increased to improve the adhesion, the condensing power of the toner layer is increased, and the above-described character void is generated.
The elastic belt is deformed corresponding to the toner layer and the paper having poor smoothness at the transfer portion. In other words, because the elastic belt deforms following local irregularities, the paper does not have excessive flatness and does not excessively increase the transfer pressure with respect to the toner layer. In contrast, a transfer image having excellent uniformity can be obtained.

  Examples of the elastic belt resin include polycarbonate, fluorine resin (ETFE, PVDF), polystyrene resin, chloropolystyrene resin, poly-α-methylstyrene resin, styrene-butadiene copolymer, and styrene-vinyl chloride copolymer. Styrene-vinyl acetate copolymer, styrene-maleic acid copolymer, styrene-acrylic acid ester copolymer (for example, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-acrylic acid) Butyl copolymer, styrene-octyl acrylate copolymer, styrene-phenyl acrylate copolymer, etc.), styrene-methacrylic acid ester copolymer (for example, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate) Copolymer, styrene-methacrylic acid Nyl copolymers, etc.), styrene resins such as styrene-α-chloroacrylic acid methyl copolymer, styrene-acrylonitrile-acrylic acid ester copolymer (monopolymer or copolymer containing styrene or styrene-substituted product) , Methyl methacrylate resin, butyl methacrylate resin, ethyl acrylate resin, butyl acrylate resin, modified acrylic resin (for example, silicone-modified acrylic resin, vinyl chloride resin-modified acrylic resin, acrylic-urethane resin, etc.), polyvinyl chloride resin , Styrene-vinyl acetate copolymer, vinyl chloride-vinyl acetate copolymer, rosin-modified maleic acid resin, phenol resin, epoxy resin, polyester resin, polyester polyurethane resin, polyethylene, polypropylene, polybutadiene, polyvinylidene chloride, ionomer tree , Polyurethane resins, silicone resins, ketone resins, ethylene - ethyl acrylate copolymer, xylene resin, polyvinyl butyral resin, polyamide resin, modified polyphenylene oxide resins, and the like. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the elastic material rubber and elastomer include butyl rubber, fluorine rubber, acrylic rubber, EPDM, NBR, acrylonitrile-butadiene-styrene rubber natural rubber, isoprene rubber, styrene-butadiene rubber, butadiene rubber, ethylene-propylene rubber, and ethylene. -Propylene terpolymer, chloroprene rubber, chlorosulfonated polyethylene, chlorinated polyethylene, urethane rubber, syndiotactic 1,2-polybutadiene, epichlorohydrin rubber, ricone rubber, fluorine rubber, polysulfide rubber, polynorbornene rubber, hydrogen Nitrile rubber, thermoplastic elastomer (eg, polystyrene, polyolefin, polyvinyl chloride, polyurethane, polyamide, polyurea, polyester, fluororesin), etc. It is below. These may be used individually by 1 type and may use 2 or more types together.

The conductive material for adjusting the resistance value is not particularly limited and may be appropriately selected depending on the purpose. For example, carbon black, graphite, metal powder such as aluminum and nickel, tin oxide, titanium oxide, antimony oxide, Conductive metal oxide such as indium oxide, potassium titanate, antimony oxide-tin oxide composite oxide (ATO), indium oxide-tin oxide composite oxide (ITO), conductive metal oxides are barium sulfate, silicic acid It may be coated with insulating fine particles such as magnesium and calcium carbonate. Of course, the conductive agent is not limited thereto.
The surface layer material is required to prevent contamination of the photoconductor with an elastic material and reduce the surface friction resistance to the transfer belt surface to reduce the adhesion force of the toner to improve the cleaning property and the secondary transfer property. The For example, materials that use at least one combination of polyurethane resin, polyester resin, epoxy resin, etc. to reduce surface energy and increase lubricity, such as fluorine resin, fluorine compound, fluorocarbon, titanium dioxide, silicon carbide, etc. These powders, at least one kind of particles, or a combination of particles having different particle diameters can be dispersed and used. Further, it is also possible to use a material having a reduced surface energy by forming a fluorine-rich layer on the surface by heat treatment, such as a fluorine-based rubber material.
The manufacturing method of the belt is not limited. For example, a centrifugal molding method in which a material is poured into a rotating cylindrical mold to form a belt, a spray coating method in which a liquid paint is sprayed to form a film, and a cylindrical mold. These include the dipping method in which the material is dipped in the material solution, the casting method in which it is injected into the inner mold and the outer mold, the method in which the compound is wound around a cylindrical mold and vulcanized and polished. It is not limited and it is common to manufacture a belt combining several manufacturing methods.

As a method for preventing elongation as the elastic belt, there are a method of forming a rubber layer in a core resin layer with little elongation, a method of putting a material for preventing elongation into the core layer, and the like, but it is limited to a specific manufacturing method. It is not a thing.
The material constituting the core layer for preventing elongation includes, for example, natural fibers such as cotton and silk; polyester fibers, nylon fibers, acrylic fibers, polyolefin fibers, polyvinyl alcohol fibers, polyvinyl chloride fibers, polyvinylidene chloride fibers, Examples thereof include synthetic fibers such as polyurethane fibers, polyacetal fibers, polyfluoroethylene fibers, and phenol fibers; inorganic fibers such as carbon fibers, glass fibers, and boron fibers; metal fibers such as iron fibers and copper fibers. These may be used individually by 1 type and may use 2 or more types together. In addition, a woven fabric or a thread may be used alone or in combination.
The yarn may be twisted in any manner, such as one or a plurality of filaments twisted, a single twisted yarn, various twisted yarns, a double yarn, or the like. Further, for example, fibers of a material selected from the above material group may be blended, or the yarn can be used after being subjected to an appropriate conductive treatment. On the other hand, the woven fabric can be any woven fabric such as knitted fabric, and a woven fabric that is woven can also be used, and naturally conductive treatment can be performed.
The manufacturing method for providing the core layer is not particularly limited and may be appropriately selected depending on the purpose. For example, a method of providing a coating layer on a woven fabric woven in a cylindrical shape on a mold or the like , A method of providing a coating layer on one or both sides of a core layer by immersing a woven fabric woven in a cylindrical shape in liquid rubber, etc., winding a thread spirally around a mold at an arbitrary pitch, and coating layer thereon And the like.
The thickness of the elastic layer depends on the hardness of the elastic layer, but if it is too thick, the surface expands and contracts and cracks are likely to occur in the surface layer. Also, it is not preferable that the thickness is too large (approximately 1 mm or more) because the amount of expansion / contraction increases and the image expands / contracts.

The transfer means (the primary transfer means and the secondary transfer means) is a transfer for peeling and charging the visible image formed on the electrostatic latent image carrier (photoconductor) to the recording medium side. It is preferable to have at least a vessel. There may be one transfer means or two or more transfer means.
Examples of the transfer device include a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device.
The recording medium is typically plain paper, but is not particularly limited as long as it can transfer an unfixed image after development, and can be appropriately selected according to the purpose. PET for OHP A base or the like can also be used.

The fixing step is a step of fixing the visible image transferred to the recording medium using a fixing device, and may be performed each time the toner of each color is transferred to the recording medium, or for the toner of each color. You may perform this simultaneously in the state which laminated | stacked this.
There is no restriction | limiting in particular as said fixing device, Although it can select suitably according to the objective, A well-known heating-pressing means is suitable. Examples of the heating and pressing means include a combination of a heating roller and a pressure roller, a combination of a heating roller, a pressure roller, and an endless belt.
The heating in the heating and pressing means is usually preferably 80 to 200 ° C.
In the present invention, for example, a known optical fixing device may be used together with or in place of the fixing step and the fixing unit depending on the purpose.

The neutralization step is a step of performing neutralization by applying a neutralization bias to the electrostatic latent image carrier, and can be suitably performed by a neutralization unit.
The neutralization means is not particularly limited, and may be appropriately selected from known neutralizers as long as it can apply a neutralization bias to the electrostatic latent image carrier. Preferably mentioned.

The cleaning step is a step of removing the electrophotographic toner remaining on the electrostatic latent image carrier, and can be suitably performed by a cleaning unit.
The cleaning means is not particularly limited as long as it can remove the electrophotographic toner remaining on the electrostatic latent image carrier, and can be appropriately selected from known cleaners. Suitable examples include brush cleaners, electrostatic brush cleaners, magnetic roller cleaners, blade cleaners, brush cleaners, web cleaners, and the like.

The recycling step is a step of recycling the electrophotographic color toner removed by the cleaning step to the developing unit, and can be suitably performed by the recycling unit.
There is no restriction | limiting in particular as said recycling means, A well-known conveyance means etc. are mentioned.

The control means is a process for controlling the respective steps, and can be suitably performed by the control means.
The control means is not particularly limited as long as the movement of each means can be controlled, and can be appropriately selected according to the purpose. Examples thereof include devices such as a sequencer and a computer.

Here, the image forming apparatus of the present invention will be described with reference to the drawings.
FIG. 6 is a schematic view showing an example of the image forming apparatus of the present invention. The image forming apparatus of FIG. 6 is an image forming apparatus using the electrostatic latent image carrier (electrophotographic photosensitive member) of the present invention, and is a drum-shaped photosensitive member 10, a charging charger 3, and a pre-transfer charger. 7, a transfer charger 111, a separation charger 111, and a pre-cleaning charger 113.
The shape of the photoreceptor 10 is not limited to a drum shape, and may be, for example, a sheet shape or an endless belt shape. Various chargers include a corotron, a scorotron, a solid state charger, a contact arrangement, or a gap between the electrostatic latent image carrier and a gap tape or a step at the end. Well-known means such as a charging roller that is disposed in proximity to each other can be used.

  The charging roller arranged close to the charging roller is less charged unevenness than the charging roller arranged in contact, and has a large margin for charging failure caused by contamination of the charging roller, and can be used without maintenance. On the other hand, there is a great hazard to the surface of the electrophotographic photosensitive member, such as the fact that the applied voltage must be increased, and there is significant wear on the outermost surface layer (charge transport layer or protective layer) using conventional polymer binders. Was causing. In addition, the charging roller arranged in the vicinity is unstable to discharge only by applying a DC voltage, leading to uneven image density, etc., and it is preferable to apply an AC voltage superimposed on the DC voltage.

As a result, since the hazard on the surface of the electrophotographic photosensitive member is extremely high, the life of the electrophotographic photosensitive member is shortened, and problems such as an increase in cost and an increase in maintenance frequency have occurred. The body is hardly worn even in the charging means, and is stably charged. In addition, since the residual potential in the exposed area is reduced and the image blur is suppressed, a good image can be stably output even during long-term repeated use.
As the transfer means, the above charger can be generally used, but a combination of a transfer charger and a separation charger as shown in the figure is effective.

Light sources such as the image exposure unit 5 and the charge removal lamp 2 emit light such as a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED), a semiconductor laser (LD), and an electroluminescence (EL). All things can be used. Various types of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range.
Such a light source or the like can irradiate the photosensitive member with light by providing a transfer step, a static elimination step, a cleaning step, or a pre-exposure step in combination with light irradiation in addition to the steps shown in FIG. .

  The toner developed on the photoconductor 10 by the developing unit 6 is transferred to the recording medium 9, but not all is transferred, and the toner remains on the photoconductor 10. If such a residual toner is not cleaned and the next copying process is performed, a charging failure or a problem in forming a latent image due to exposure occurs. Therefore, it is generally necessary to remove residual toner using a cleaning means. As the cleaning means, the cleaning brush 114 or the blade 115 may be used alone or in combination. Known cleaning brushes such as a fur brush and a mag fur brush are used as the cleaning brush.

The cleaning blade 115 includes an elastic body having a low coefficient of friction, such as urethane resin, silicone resin, fluororesin, urethane elastomer, silicone elastomer, and fluoroelastomer. As the cleaning blade 115, a thermosetting urethane resin is preferable, and a urethane elastomer is particularly preferable from the viewpoints of wear resistance, ozone resistance, and contamination resistance. Elastomer includes rubber. The cleaning blade 115 preferably has a hardness (JIS-A) in the range of 65 to 85 degrees. The cleaning blade 15 preferably has a thickness of 0.8 to 3.0 mm and a protruding amount of 3 to 15 mm. Furthermore, as other conditions, the contact pressure, the contact angle, the amount of biting, and the like can be determined as appropriate.
The cleaning means that comes into contact with such an electrostatic latent image carrier (electrophotographic photosensitive member) has high toner removal performance, but naturally, it gives mechanical hazard to the electrophotographic photosensitive member, and the surface of the electrophotographic photosensitive member Causes layer wear.
Since the electrostatic latent image bearing member of the present invention has extremely high wear resistance of the protective layer, it is possible to stably output a good image even in an image forming apparatus having a cleaning unit in contact with the surface.

  FIG. 7 is a schematic view showing another example of the process using the image forming apparatus according to the present invention. In FIG. 7, a photosensitive member 122 is the latent electrostatic image bearing member of the present invention, and is driven by a driving roller 123, charged by a charging charger 220, image exposure by an image exposure light source 121, and development (not shown). Then, transfer using the transfer charger charger 125, cleaning with the cleaning brush 126, and charge removal with the charge removal light source 127 are repeated.

FIG. 8 is a schematic configuration diagram of a full-color image forming apparatus to which the electrophotographic photosensitive member of the present invention is applied. In FIG. 8, the photosensitive member 156 is driven to rotate counterclockwise in the drawing, and its surface is uniformly charged by a charging charger 153 using a corotron or a scorotron, and then laser light emitted from a laser optical device (not shown). The electrostatic latent image is carried in response to the scanning of L. Since this scanning is performed based on single-color image information obtained by decomposing a full-color image into yellow, magenta, cyan, and black color information, a single-color electrostatic image of yellow, magenta, cyan, or black is formed on the photosensitive drum 156. A latent image is formed.
A revolver developing unit 250 is disposed on the left side of the photosensitive drum 156 in FIG. This has a yellow developing unit, a magenta developing unit, a cyan developing unit, and a black developing unit in a rotating drum-shaped casing, and each developing unit is sequentially moved to a developing position facing the photosensitive drum 156 by rotation. Move. The yellow developer, magenta developer, cyan developer, and black developer are for developing an electrostatic latent image by attaching yellow toner, magenta toner, cyan toner, and black toner, respectively. On the photosensitive drum 156, electrostatic latent images for yellow, magenta, cyan, and black are sequentially formed, and these are sequentially developed by the developing units of the revolver developing unit 250, so that a yellow toner image, a magenta toner image, and a cyan toner are developed. A toner image and a black toner image are obtained.

  An intermediate transfer unit is disposed on the downstream side of the photosensitive drum 156 from the development position. This is because an intermediate transfer belt 158 stretched by a tension roller 159a, an intermediate transfer bias roller 157 as a transfer means, a secondary transfer backup roller 159b, and a belt drive roller 159c is driven by rotation of the belt drive roller 159c. Move endlessly clockwise. The yellow toner image, magenta toner image, cyan toner image, and black toner image developed on the photosensitive drum 156 enter an intermediate transfer nip where the photosensitive drum 156 and the intermediate transfer belt 158 are in contact with each other. Then, while being influenced by the bias from the intermediate transfer bias roller 157, the toner image is superimposed on the intermediate transfer belt 158 and intermediately transferred to form a four-color superimposed toner image. The intermediate transfer method in which the toner images are superimposed using such an intermediate transfer belt is advantageous for color misregistration because the relative positioning of the electrophotographic photosensitive member and the intermediate transfer member can be relatively easily and accurately performed. Therefore, it can be said that this is an effective means for obtaining a high-quality full-color image.

  The surface of the photosensitive drum 156 that has passed through the intermediate transfer nip with rotation is cleaned by the drum cleaning unit 155 with residual transfer toner. The cleaning unit 155 cleans the transfer residual toner with a cleaning roller to which a cleaning bias is applied. However, the cleaning unit 155 may use a cleaning brush such as a fur brush or a mag fur brush, or a cleaning blade.

  The surface of the photosensitive drum 156 from which the transfer residual toner has been cleaned is discharged by the discharging lamp 154. As the charge removal lamp 154, a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED), a semiconductor laser (LD), an electroluminescence (EL), or the like is used. A semiconductor laser is used as the light source of the laser optical device. About these emitted lights, you may make it use only a desired wavelength range by various filters, such as a sharp cut filter, a band pass filter, a near-infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter.

  A transfer unit including various rollers such as a transfer belt, a transfer bias roller, and a driving roller is disposed below the intermediate transfer unit in FIG. 8, and on the left side in FIG. 165 is disposed. In the transfer unit, the endless transfer belt may be moved in the vertical direction in FIG. 8 by a moving means (not shown), and at least one color toner image (yellow toner image) on the intermediate transfer belt 158. Alternatively, when the two-color or three-color superimposed toner image passes through a position facing the paper transfer bias roller 163, the toner image moves to a position where it does not contact the intermediate transfer belt 158. Then, before the leading end of the four-color superimposed toner image on the intermediate transfer belt 158 enters the position facing the paper transfer bias roller 163, it moves to the contact position with the intermediate transfer belt 158 to move to the secondary transfer nip. Form.

  On the other hand, the registration roller pair 161 that sandwiches the recording medium 160 sent from a paper feeding cassette (not shown) between two rollers can superimpose the recording medium 160 on the four-color superimposed toner image on the intermediate transfer belt 158. Feed toward the secondary transfer nip at the timing. The four-color superimposed toner image on the intermediate transfer belt 158 is secondarily transferred collectively onto the recording medium 160 under the influence of the secondary transfer bias from the paper transfer bias roller 163 in the secondary transfer nip. By this secondary transfer, a full color image is formed on the recording medium 160.

Then, the recording medium 160 on which the full color image is formed is sent to the paper conveying belt 164 by the transfer belt 162.
The conveyance belt 164 sends the recording medium 160 received from the transfer unit into the fixing device 165.
The fixing device 165 conveys the fed recording medium 160 while being sandwiched in a fixing nip formed by the contact between the heating roller and the backup roller.
The full-color image on the recording medium 160 is fixed on the recording medium 160 under the influence of the heating from the heating roller and the pressure in the fixing nip.

  Although not shown, a bias for attracting the recording medium P is applied to the transfer belt 162 and the conveyance belt 164. In addition, a paper neutralization charger that neutralizes the recording medium 160 and three belt neutralization chargers that neutralize each belt (intermediate transfer belt 158, transfer belt 162, and conveyance belt 164) are provided. The intermediate transfer unit also includes a belt cleaning unit having the same configuration as that of the drum cleaning unit 155, thereby cleaning the transfer residual toner on the intermediate transfer belt 158.

Here, the image forming apparatus shown in FIG. 9 is a tandem color image forming apparatus using the electrostatic latent image carrier (electrophotographic photosensitive member) of the present invention. The tandem image forming apparatus 120 includes a copying apparatus main body 150, a paper feed table 200, a scanner 300, and an automatic document feeder (ADF) 400.
The copying apparatus main body 150 is provided with an endless belt-like intermediate transfer member 50 at the center. The intermediate transfer member 50 is stretched around the support rollers 14, 15, and 16 and can be rotated clockwise in FIG. 9. An intermediate transfer member cleaning device 17 for removing residual toner on the intermediate transfer member 50 is disposed in the vicinity of the support roller 15. The intermediate transfer member 50 stretched between the support roller 14 and the support roller 15 is a tandem type in which four image forming units 18 of yellow, cyan, magenta, and black are arranged to face each other along the conveyance direction. A developing device 120 is disposed. An exposure device 21 is disposed in the vicinity of the tandem developing device 120. A secondary transfer device 22 is disposed on the side of the intermediate transfer member 50 opposite to the side on which the tandem developing device 120 is disposed. In the secondary transfer device 22, a secondary transfer belt 24, which is an endless belt, is stretched around a pair of rollers 23, and the recording medium conveyed on the secondary transfer belt 24 and the intermediate transfer member 50 are in contact with each other. Is possible. A fixing device 25 is disposed in the vicinity of the secondary transfer device 22.
In the tandem image forming apparatus 100, a sheet reversing device 28 for reversing the recording medium in order to form an image on both sides of the recording medium is disposed in the vicinity of the secondary transfer device 22 and the fixing device 25. Yes.

  Next, formation of a full-color image (color copy) using the tandem developing device 120 will be described. That is, first, a document is set on the document table 130 of the automatic document feeder (ADF) 400, or the automatic document feeder 400 is opened and the document is set on the contact glass 32 of the scanner 300. 400 is closed.

  When a start switch (not shown) is pressed, when the document is set on the automatic document feeder 400, the document is transported and moved onto the contact glass 32, and then the document is set on the contact glass 32. Immediately after that, the scanner 300 is driven, and the first traveling body 33 and the second traveling body 34 travel. At this time, light from the light source is irradiated by the first traveling body 33 and reflected light from the document surface is reflected by the mirror in the second traveling body 34 and is received by the reading sensor 36 through the imaging lens 35 to be color. An original (color image) is read and used as black, yellow, magenta, and cyan image information.

  Each image information of black, yellow, magenta and cyan is stored in each image forming means 18 (black image forming means, yellow image forming means, magenta image forming means and cyan image forming means in the tandem developing device 120. ) And black, yellow, magenta and cyan toner images are formed in the respective image forming means. That is, each image forming means 18 (black image forming means, yellow image forming means, magenta image forming means, and cyan image forming means) in the tandem developing device 120 is photosensitive as shown in FIG. On the basis of the body 10 (the black photoreceptor 10K, the yellow photoreceptor 10Y, the magenta photoreceptor 10M, and the cyan photoreceptor 10C), the charger 60 that uniformly charges the photoreceptor, and each color image information. The photosensitive member is exposed to each color image corresponding image (L in FIG. 10), and an electrostatic latent image corresponding to each color image is formed on the photosensitive member. A developing unit 61 that develops using color toners (black toner, yellow toner, magenta toner, and cyan toner) to form a toner image with each color toner, and intermediate the toner image A transfer charger 62 for transferring the image onto the photoconductor 50, a photoconductor cleaning device 63, and a static eliminator 64 are provided, and each single color image (black image, yellow image) is based on the image information of each color. , Magenta image and cyan image) can be formed. The black image, the yellow image, the magenta image, and the cyan image formed in this way are formed on the black photoconductor 10K on the intermediate transfer member 50 that is rotationally moved by the support rollers 14, 15, and 16, respectively. The black image, the yellow image formed on the yellow photoconductor 10Y, the magenta image formed on the magenta photoconductor 10M, and the cyan image formed on the cyan photoconductor 10C are sequentially transferred (primary transfer). Is done. Then, the black image, the yellow image, the magenta image, and the cyan image are superimposed on the intermediate transfer member 50 to form a composite color image (color transfer image).

On the other hand, in the paper feed table 200, one of the paper feed rollers 142 is selectively rotated to feed out a sheet (recording paper) from one of the paper feed cassettes 144 provided in multiple stages in the paper bank 143. Each sheet is separated and sent to the paper feed path 146, transported by the transport roller 147, guided to the paper feed path 148 in the copying machine main body 150, and abutted against the registration roller 49 and stopped. Alternatively, the sheet feed roller 142 is rotated to feed out sheets (recording paper) on the manual feed tray 54, separated one by one by the separation roller 52, put into the manual feed path 53, and abutted against the registration roller 49 and stopped. . The registration roller 49 is generally used while being grounded, but may be used in a state where a bias is applied to remove paper dust from the sheet.
Then, the registration roller 49 is rotated in synchronization with the synthesized color image (color transfer image) synthesized on the intermediate transfer member 50, and a sheet (recording paper) is interposed between the intermediate transfer member 50 and the secondary transfer device 22. And transferring the composite color image (color transfer image) onto the sheet (recording paper) by the secondary transfer device 22, thereby transferring the color image onto the sheet (recording paper). Is formed. The residual toner on the intermediate transfer member 50 after image transfer is cleaned by the intermediate transfer member cleaning device 17.

  The sheet (recording paper) on which the color image has been transferred is conveyed by the secondary transfer device 22 and sent to the fixing device 25, where the combined color image (color) is generated by heat and pressure. (Transfer image) is fixed on the sheet (recording paper). Thereafter, the sheet (recording paper) is switched by the switching claw 55 and discharged by the discharge roller 56 and stacked on the discharge tray 57, or switched by the switching claw 55 and reversed by the sheet reversing device 28 and transferred again. After being guided to the position and recording an image on the back surface, the image is discharged by the discharge roller 56 and stacked on the discharge tray 57.

  In the tandem method, latent image formation and development of each color can be performed in parallel, so that the image formation speed can be much higher than that of the revolver method. Furthermore, the printer of FIG. 9 also employs an intermediate transfer system, and by mounting the electrophotographic photosensitive member of the present invention, a high-quality full-color image with little color misregistration can be repeated at a very high speed for a long period of time. Can be output.

(Process cartridge)
The process cartridge of the present invention integrally includes the electrostatic latent image carrier of the present invention and at least one means selected from a charging means, a developing means, and a cleaning means. With other means selected.
The developing means includes at least a developer container that contains the toner or the developer, and a developer carrier that carries and conveys the toner or developer contained in the developer container. Furthermore, a layer thickness regulating member for regulating the thickness of the toner layer to be carried may be provided.

Here, for example, as shown in FIG. 11, the process cartridge includes a photosensitive member 101, includes a charger 102, a developing unit 104, and a cleaning unit 107, and further includes other units as necessary. Become. Reference numeral 103 denotes an exposure unit, 105 denotes a recording medium, and 108 denotes a conveyance roller.
As the photoconductor 101, the above-described electrostatic latent image carrier of the present invention is used.
As the exposure unit 103, a light source capable of writing with high resolution is used.
An arbitrary charging member is used as the charger 102.

The image forming apparatus of the present invention is constructed by integrally combining the electrostatic latent image carrier and the components such as a developing device and a cleaning device as a process cartridge, and this unit can be attached to and detached from the apparatus main body. It may be configured. Further, at least one of a charger, an image exposure device, a developing device, a transfer or separation device, and a cleaning device is integrally supported together with an electrostatic latent image carrier to form a process cartridge, and is detachably attached to the apparatus main body. One unit may be detachable using guide means such as a rail of the apparatus main body.
As a result, the electrostatic latent image carrier and other process members can be easily exchanged in a short time, so that the time required for maintenance can be shortened and the cost can be reduced. Further, since the process member and the electrostatic latent image carrier are integrated, there are also advantages such as improvement of relative position accuracy.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to the following Example.

Example 1
-Production of electrostatic latent image carrier-
15 parts by mass of alkyd resin (Beckolite M6401-50, manufactured by Dainippon Ink & Chemicals) and 10 parts by mass of melamine resin (Super Becamine G-821-60, manufactured by Dainippon Ink & Chemicals) 150 parts by mass of methyl ethyl ketone Dissolved in. To this, 90 parts by mass of titanium oxide powder (Taipere CR-EL, manufactured by Ishihara Sangyo Co., Ltd.) was added and dispersed with a ball mill for 12 hours to prepare an undercoat layer coating solution. This was coated on a cylindrical aluminum substrate having a diameter of 30 mm by a dip coating method and dried at 130 ° C. for 20 minutes to form an undercoat layer having a thickness of 3.5 μm.

Next, 4 parts by mass of polyvinyl butyral resin (XYHL, manufactured by UCC) was dissolved in 150 parts by mass of cyclohexanone. To this, 10 parts by mass of a bisazo pigment represented by the following structural formula (A) was added and dispersed with a ball mill for 48 hours, and then 210 parts by mass of cyclohexanone was added and dispersed for 3 hours. This dispersion was taken out into a container and diluted with cyclohexanone so that the solid content was 1.5% by mass. The obtained charge generation layer coating solution was applied onto the undercoat layer and dried at 130 ° C. for 20 minutes to form a charge generation layer having a thickness of 0.2 μm.

Next, 10 parts by mass of bisphenol Z-type polycarbonate resin and 0.002 parts by mass of silicone oil (KF-50, manufactured by Shin-Etsu Chemical Co., Ltd.) were dissolved in 100 parts by mass of tetrahydrofuran. A charge transport layer coating solution was prepared by adding 10 parts by mass of a charge transport material represented by the following structural formula (B) to this solution.
The obtained charge transport layer coating solution was applied onto the charge generation layer by a dip coating method and dried at 110 ° C. for 20 minutes to form a charge transport layer having a thickness of 20 μm.

Next, 7 parts by mass of methyltrimethoxysilane was placed in a flask, cooled to about 0 ° C. with ice water, 3 parts by mass of a 1% by mass acetic acid aqueous solution was added dropwise over 1 hour, and then stirred for 6 hours. The temperature was raised to 25 ° C. To this solution, 18 parts by mass of cyclohexanone and 18 parts by mass of ethanol were added and stirred. Next, 7 parts by mass of a non-crosslinkable charge transport material represented by the following structural formula (C) was added and dissolved. Next, 0.5 parts by mass of tris (2,4-pentanedionato) aluminum (III) and 0.15 parts by mass of acetylacetone were added to prepare a protective layer coating solution.

  The obtained protective layer coating solution was applied onto the charge transport layer by a spray coating method. Thereafter, the cylindrical aluminum substrate was left to rotate for 10 minutes and dried by touching, and then heated and cured at 130 ° C. for 30 minutes to form a protective layer having a thickness of 2 μm. Thus, the electrostatic latent image carrier of Example 1 was produced.

(Example 2)
-Production of electrostatic latent image carrier-
In Example 1, the electrostatic latent image carrier of Example 2 was produced in the same manner as in Example 1 except that the protective layer coating solution prepared as follows was used. .
<Preparation of protective layer coating solution>
3 parts by mass of methyltrimethoxysilane and 4 parts by mass of phenyltrimethoxysilane were placed in a flask and cooled to about 0 ° C. with ice water, and then 3 parts by mass of a 1% by mass acetic acid aqueous solution was added dropwise over 1 hour, followed by stirring. However, the temperature was raised to 25 ° C. over 6 hours. To this solution, 18 parts by mass of cyclohexanone and 18 parts by mass of ethanol were added and stirred. Subsequently, 7 parts by mass of the non-crosslinkable charge transport material represented by the structural formula (C) was added and dissolved. Further, 0.5 parts by mass of tris (2,4-pentanedionato) aluminum (III) and 0.15 parts by mass of acetylacetone were added to prepare a protective layer coating solution.

(Example 3)
-Production of electrostatic latent image carrier-
In Example 1, the electrostatic latent image carrier of Example 3 was produced in the same manner as in Example 1 except that the protective layer coating solution prepared as follows was used. .
<Protective layer coating solution>
Mixing 10 parts by mass of curable siloxane resin (NSC 1274, manufactured by Nippon Seika Co., Ltd.) and 7 parts by mass of the non-crosslinked charge transporting material represented by the structural formula (C) with 18 parts by mass of cyclohexanone and 18 parts by mass of ethanol A protective layer coating solution was prepared by dissolving in a solvent.

Example 4
-Production of electrostatic latent image carrier-
In Example 1, the electrophotographic photosensitive member of Example 4 was produced in the same manner as in Example 1 except that the protective layer coating solution was prepared as follows.
<Protective layer coating solution>
10 parts by mass of curable siloxane resin containing colloidal silica (NSC 1500N, manufactured by Nippon Seika Co., Ltd.), 7 parts by mass of the non-crosslinked charge transporting material represented by the above structural formula (C), 18 parts by mass of cyclohexanone, and ethanol 18 A protective layer coating solution was prepared by dissolving in a mixed solvent of parts by mass.

(Example 5)
-Production of electrostatic latent image carrier-
In Example 1, the electrostatic latent image carrier of Example 4 was produced in the same manner as in Example 1 except that the protective layer coating solution was prepared as follows.
<Protective layer coating solution>
10 parts by mass of curable siloxane resin containing colloidal silica (NSC 2319, manufactured by Nippon Seika Co., Ltd.), 7 parts by mass of the non-crosslinked charge transporting substance represented by the above structural formula (C), 18 parts by mass of cyclohexanone, and ethanol 18 A protective layer coating solution was prepared by dissolving in a mixed solvent of parts by mass.

(Example 6)
-Production of electrostatic latent image carrier-
In Example 3, the electrostatic latent image of Example 6 was obtained in the same manner as in Example 3 except that the addition amount of the non-crosslinkable charge transport material represented by the structural formula (C) was changed to 4 parts by mass. A carrier was prepared.

(Example 7)
-Production of electrostatic latent image carrier-
In Example 3, the electrostatic latent image of Example 7 was obtained in the same manner as in Example 3 except that the addition amount of the non-crosslinkable charge transport material represented by the structural formula (C) was changed to 20 parts by mass. A carrier was prepared.

<Evaluation of wear amount and durability image>
Each electrostatic latent image carrier thus obtained was replaced with a modified machine (image exposure light source 655 nm semiconductor laser) of a full-color composite machine (Imagio Color 5100, manufactured by Ricoh Co., Ltd.). The contact pressure is doubled and the load is applied to the wear of the photosensitive member), and the charger voltage is adjusted so that the non-exposed portion potential (VD) becomes −700 V, and then 600 dpi. A running test for outputting a test image having an A4 size and an image area ratio of 5% was performed by considerable writing, and the amount of wear was measured from the difference in the thickness of the photosensitive layer before and after the running test. The results are shown in Table 1. The thickness of the photosensitive layer was measured using an eddy current thickness gauge Fischer scope MMS (manufactured by Fischer).
Further, the photoconductor after the running test was subjected to 100 running tests and durable image output under an environment of 10 ° C., and the image quality was evaluated. The results are shown in Table 1.

<Comprehensive evaluation>
The above results were comprehensively evaluated and evaluated according to the following criteria. The results are shown in Table 1.
〔Evaluation criteria〕
○: Good △: Slightly bad (level that can be actually used)
×: Defect (level that is not actually usable)

  The electrostatic latent image carrier of the present invention is very excellent in abrasion resistance and can stably output a good image even in the initial stage and after a durability test by actual machine running. It is suitably used for an image forming method, an image forming apparatus, and a process cartridge capable of forming a quality image.

FIG. 1 is a schematic cross-sectional view showing an example of the layer structure of the electrostatic latent image carrier of the present invention. FIG. 2 is a schematic cross-sectional view showing another example of the layer structure of the electrostatic latent image carrier of the present invention. FIG. 3 is a schematic cross-sectional view showing another example of the layer structure of the electrostatic latent image carrier of the present invention. FIG. 4 is a schematic cross-sectional view showing another example of the layer structure of the electrostatic latent image carrier of the present invention. FIG. 5 is a schematic cross-sectional view showing another example of the layer structure of the electrostatic latent image carrier of the present invention. FIG. 6 is a schematic view showing an example of the image forming apparatus of the present invention. FIG. 7 is a schematic configuration diagram showing another example of the image forming apparatus of the present invention. FIG. 8 is a schematic configuration diagram showing still another example of the image forming apparatus of the present invention. FIG. 9 is a schematic explanatory view showing an example in which the image forming method of the present invention is carried out by the image forming apparatus of the present invention (tandem color image forming apparatus). FIG. 10 is a partially enlarged schematic explanatory diagram of the image forming apparatus shown in FIG. FIG. 11 is a schematic view showing an example of the process cartridge of the present invention.

Explanation of symbols

10 Photoconductor (Photoconductor drum)
10K black photoconductor 10Y yellow photoconductor 10M magenta photoconductor 10C cyan photoconductor 14 support roller 15 support roller 16 support roller 17 intermediate transfer cleaning device 18 image forming means 20 charging roller 21 exposure device 22 secondary transfer device 23 Roller 24 Secondary transfer belt 25 Fixing device 26 Fixing belt 27 Pressure roller 28 Sheet reversing device 30 Exposure device 32 Contact glass 33 First traveling member 34 Second traveling member 35 Imaging lens 36 Reading sensor 40 Developing device 41 Developing belt 42K Developer container 42Y Developer container 42M Developer container 42C Developer container 43K Developer supply roller 43Y Developer supply roller 43M Developer supply roller 43C Developer supply roller 44K Developer roller 44Y Developer roller 44M Developer Roller 44C Developing roller 45K Black developing unit 45Y Yellow developing unit 45M Magenta developing unit 45C Cyan developing unit 49 Registration roller 50 Intermediate transfer member 51 Roller 52 Separating roller 53 Manual feed path 54 Manual feed tray 55 Switching claw 56 Discharge roller 57 discharge tray 58 corona charger 60 cleaning device 61 developing device 62 transfer charger 63 photoconductor cleaning device 64 discharger 70 discharger lamp 80 transfer roller 90 cleaning device 95 recording medium 100 image forming device 101 photoconductor 102 charger 103 exposure unit DESCRIPTION OF SYMBOLS 104 Developing means 107 Cleaning means 110 Belt type image fixing device 120 Tandem type developing device 121 Heating roller 122 Fixing roller 123 Fixing belt 124 Pressure roller 125 Heating source 126 Clean Ning roller 127 temperature sensor 130 document table 142 paper feed roller 143 paper bank 144 paper feed cassette 145 separation roller 146 paper feed path 147 transport roller 148 paper feed path 150 copying machine main body 200 paper feed table 201 support 202 photosensitive layer 203 charge generation Layer 204 charge transport layer 205 undercoat layer 206 protective layer 207 intermediate layer 210 image fixing device 220 heating roller 230 pressure roller 300 scanner 400 automatic document feeder (ADF)

Claims (16)

A curable siloxane comprising a support and at least a photosensitive layer and a protective layer in this order on the support, and the protective layer is formed by crosslinking an organosilicon compound having either a hydroxyl group or a hydrolyzable group resin and, an electrostatic latent image bearing member which comprises a curable siloxane resin and uncrosslinked following structural uncrosslinked charge transporting material that is represented by formula.

  2. The electrostatic latent image according to claim 1, wherein a mass ratio of the curable siloxane resin to the non-crosslinked charge transporting substance (curable siloxane resin / non-crosslinked charge transporting substance) is 6/4 to 3/7. Carrier.   The electrostatic latent image carrier according to claim 1, wherein the protective layer contains fine particles.   The electrostatic latent image carrier according to claim 3, wherein the fine particles are at least one selected from colloidal silica, titanium oxide, and aluminum oxide.   The electrostatic latent image carrier according to claim 1, wherein the protective layer has a thickness of 1 to 15 μm.   6. The electrostatic latent image carrier according to claim 1, wherein the photosensitive layer is a single-layer type photosensitive layer.   7. The electrostatic latent image carrier according to claim 1, wherein the photosensitive layer is a laminated photosensitive layer having at least a charge generation layer and a charge transport layer in this order on a support. An electrostatic latent image carrier, electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, and developing the electrostatic latent image with toner to form a visible image An image forming apparatus having at least developing means for transferring, transfer means for transferring the visible image to a recording medium, and fixing means for fixing the transferred image transferred to the recording medium,
An image forming apparatus, wherein the latent electrostatic image bearing member is the latent electrostatic image bearing member according to claim 1.   The image forming apparatus according to claim 8, wherein the image forming apparatus includes a cleaning unit that contacts the surface of the electrostatic latent image carrier and removes toner remaining on the surface of the electrostatic latent image carrier.   The electrostatic latent image forming means has a charger and an exposure device. The charger is arranged in contact or non-contact with the electrostatic latent image carrier, and static electricity is generated by applying DC and AC voltages in a superimposed manner. The image forming apparatus according to claim 8, wherein the surface of the electrostatic latent image carrier is charged.   The charger is a charging roller arranged in a non-contact proximity by means for giving a gap to the electrostatic latent image carrier, and a surface of the electrostatic latent image carrier is applied by applying a direct current and an alternating voltage to the charging roller. The image forming apparatus according to claim 10, which is charged.   The image forming apparatus according to claim 8, wherein the image forming apparatus forms a color image by sequentially superposing a plurality of color toners.   13. The tandem type image forming apparatus according to claim 8, wherein the image forming apparatus is a tandem type including a plurality of image forming elements each having at least an electrostatic latent image carrier, an electrostatic latent image forming unit, a developing unit, and a transfer unit. Image forming apparatus.   An image forming apparatus includes an intermediate transfer member on which a toner image formed on an electrostatic latent image carrier is primarily transferred, and a transfer unit that secondarily transfers the toner image carried on the intermediate transfer member to a recording medium. 14. A plurality of color toner images are sequentially superimposed on an intermediate transfer member to form a color image, and the color image is secondarily transferred collectively onto a recording medium. Image forming apparatus. An electrostatic latent image forming step of forming an electrostatic latent image on the electrostatic latent image carrier, a developing step of developing the electrostatic latent image with toner to form a visible image, and the visible image An image forming method including at least a transfer step of transferring the image to a recording medium and a fixing step of fixing the transferred image transferred to the recording medium,
The image forming method, wherein the electrostatic latent image carrier is the electrostatic latent image carrier according to claim 1.   8. A process cartridge comprising the electrostatic latent image carrier according to claim 1 and at least one unit selected from a charging unit, a developing unit, and a cleaning unit.

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