JP2004093863A - Electrophotographic device, electrophotographic sensitive body and process cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic device, an electrophotographic sensitive body and a process cartridge which does not cause an image defect due to the abnormality of an electrophotographic sensitive body such as toner fusion and filming and has a satisfactory electrophotographic characteristic even in the repeated use thereof. <P>SOLUTION: The image forming device is provided with the electrophotographic sensitive body, a toner image forming means which forms an image with toner on the electrophotographic sensitive body, an intermediate transfer body which is brought into contact with the electrophotographic sensitive body and moves, a means for primarily transferring a toner image formed on the electrophotographic sensitive body to an intermediate transfer body on the first transfer position of the intermediate transfer body and a transfer means for secondarily transferring the toner image transferred on the intermediate transfer body to transfer material on the second transfer position of the intermediate transfer body. Therein, the working amount of elastic deformation We on an indentation test up to the depth of 1μm on the surface layer is ≥45% for the working amount Wt of the whole deformation. The electrophotographic sensitive body is disposed on the image forming device and the process cartridge is freely detachably and detachably disposed on the image forming device. <P>COPYRIGHT: (C)2004,JPO

Description

下記式（Ｂ）の構成単位で示されるポリアリレート樹脂１０部を、
【００５９】
【化２】

モノクロロベンゼン５０部／ジクロロメタン１０部の混合溶媒に溶解した。この塗料を前述の電荷発生層の上に浸漬法で塗布し、１１０℃で１時間乾燥し、膜厚が２３μｍの電荷輸送層を形成した。
【００６０】
この様にして作製した電子写真感光体の表面押し込み試験における弾性変形仕事量Ｗｅを測定したところ、Ｗｔに対して４６．８％であった。この電子写真感光体を、中間転写ベルトを搭載した図２で示される画像形成装置に装着し、連続２００００枚の通紙耐久を行い、目視にて画像評価を行った。この装置の電子写真感光体と中間転写体の周速差は１０１％である。画像評価結果を表１に示す。
【００６１】
（実施例２）
実施例１において、式（Ｂ）の代わりに、下記式（Ｃ）の構成単位で示されるポリアリレート樹脂
【００６２】
【化３】

を１０部使用した以外は、実施例１と同様にして電子写真感光体を作製した。この電子写真感光体の弾性変形仕事量Ｗｅは４８．８％であった。この電子写真感光体を前記の画像形成装置に装着し、連続２００００枚の通紙耐久を行い、目視にて画像評価を行った。結果を表１に示す。
【００６３】
（実施例３）
実施例１において、電荷輸送材料（Ａ）を７部にした以外は、実施例１と同様にして電子写真感光体を作製した。この電子写真感光体の弾性変形仕事量Ｗｅは５０．５％であった。この電子写真感光体を前記の画像形成装置に装着し、連続２００００枚の通紙耐久を行い、目視にて画像評価を行った。結果を表１に示す。
【００６４】
（実施例４）
電荷輸送材料（Ａ）を２部、下記式（Ｄ）で示される電荷輸送材料
【００６５】
【化４】

を８部にした以外は、実施例１と同様にして電子写真感光体を作製した。この電子写真感光体の弾性変形仕事量Ｗｅは４６．５％であった。この電子写真感光体を前記の画像形成装置に装着し、連続２００００枚の通紙耐久を行い、目視にて画像評価を行った。結果を表１に示す。
【００６６】
（実施例５）
実施例１の中間転写ベルトを、＃２０００番の耐水研磨紙で研磨し、ベルト表面の水との接触角が１１５°、Ｒｚが１．２５μｍの中間転写ベルトにした。この中間転写ベルトを、図２の画像形成装置に搭載し、電子写真感光体は実施例１に記載の電子写真感光体を用いて、連続２００００枚の通紙耐久を行い、目視にて画像評価を行った。結果は表１に示す。
【００６７】
（実施例６）
図２で示される中間転写体を用いた画像形成装置の代わりに、搬送ベルト上の転写材に電子写真感光体上現像剤を直接転写する方式を用いた画像形成装置を用いて連続２００００枚の通紙耐久を行い、目視にて画像評価を行った。結果は表１に示す。
【００６８】
（比較例１）
式（Ｂ）で示されるポリアリレート樹脂の代わりに、ビスフェノールＡ型ポリカーボネート樹脂１０部を用いた以外は、実施例１と同様にして電子写真感光体を作製した。この電子写真感光体の弾性変形仕事量Ｗｅは４３．２％であった。
この電子写真感光体を前記の画像形成装置に装着し、連続２００００枚の通紙耐久を行い、目視にて画像評価を行った。結果を表１に示す。
【００６９】
（比較例２）
実施例１において、電荷輸送材料（Ａ）を３０部にした以外は、実施例１と同様にして電子写真感光体を作製した。この電子写真感光体の弾性変形仕事量Ｗｅは４１．８％であった。この電子写真感光体を前記の画像形成装置に装着し、連続２００００枚の通紙耐久を行い、目視にて画像評価を行った。結果を表１に示す。
【００７０】
（比較例３）
実施例１において、式（Ｂ）で示されるポリアリレート樹脂を５部にした以外は、実施例１と同様にして電子写真感光体を作製した。この電子写真感光体の弾性変形仕事量Ｗｅは４２．９％であった。この電子写真感光体を前記の画像形成装置に装着し、連続２００００枚の通紙耐久を行い、目視にて画像評価を行った。結果を表１に示す。
【００７１】
【表１】

【００７２】
【発明の効果】
以上説明したように、本発明によれば、電子写真感光体に接触して移動する中間転写体と、電子写真感光体に形成されたトナー像を中間転写体の第１の転写位置でこの中間転写体に１次転写するための手段と、中間転写体に転写されたトナー像を中間転写体の第２の転写位置で転写材に２次転写する転写手段を有する画像形成装置について、電子写真感光体へのトナー融着やフィルミングを防止することによって、良好な安定した画像が得られる画像形成装置及びプロセスカートリッジを提供することが可能となった。
【図面の簡単な説明】
【図１】フィッシャー硬度計における測定チャート例である。
【図２】複数の電子写真感光体を有するフルカラー画像形成装置の概略構成を示す図である。
【図３】電子写真感光体と帯電ローラーの層構成を示す図である。
【符号の説明】
１　　感光ドラム
１ａ　導電層
１ｂ　下引き層
１ｃ　電荷発生層
１ｄ　電荷輸送層
２　　１次帯電器（帯電ローラ）
２ａ　芯金
２ｂ　下層
２ｃ　中間層
２ｄ　表層
２ｅ　押し圧ばね
２ｆ　帯電ローラクリーニング部材
２ｇ　支持部材
３　　露光光
１０　　転写材ガイド
１１　　給紙ローラー
１３　　感光ドラムのクリーニング装置
１５　　定着器
１６　　中間転写体のクリーニング装置
２０　　中間転写ベルト
２８　　バイアス電源
４１　　イエロー色現像装置
４２　　マゼンタ色現像装置
４３　　シアン色現像装置
４４　　ブラック色現像装置
６２　　１次転写ローラー
６３　　２次転写ローラー
６４　　２次転写対向ローラー
６７　　除電帯電器
Ｐ　　転写材[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electrophotographic photoreceptor, an image forming apparatus, and a process cartridge detachable from the apparatus, and more particularly, to an electrophotographic photoreceptor having a surface layer having a specific elastic deformation rate, and an image provided with the electrophotographic photoreceptor. The present invention relates to a forming apparatus and a process cartridge detachable from the apparatus.
[0002]
[Prior art]
An image forming apparatus using an intermediate transfer body is an image forming apparatus for transferring an image from a first image carrier to a second image carrier adhered to or adsorbed on a transfer drum (Japanese Patent Application Laid-Open No. 63-1988). No. 301960) is superior in the following points.
[0003]
That is, processing and control (for example, gripping by a gripper, sucking, and giving a curvature) are not required for the point that color misregistration at the time of superimposing toner images of each color is small and for the second image carrier. Therefore, a variety of second image carriers can be selected.
[0004]
For example, the paper can be selected from thin paper (40 g / m ² paper) to thick paper (200 g / m ² paper), and the width is not limited, and the length is not limited. Therefore, it is also possible to use envelopes, postcards and label paper. As described above, the intermediate transfer type full-color copying machine and printer have many advantages, and copying machines and printers equipped with the intermediate transfer member are already becoming widespread.
[0005]
In addition, with the rapid spread of image input devices such as personal computers, digital cameras, and image scanners in recent years, the demand for full-color printers and copiers has also expanded significantly, making it possible to sufficiently respond to a wide range of users and use environments. It is becoming necessary. Therefore, it is necessary to reduce the maintenance cost, improve the ease of maintenance, reduce the size and cost of the apparatus, and achieve a stable image quality that is not affected by temperature and humidity.
[0006]
However, in the image forming apparatus equipped with the above-described intermediate transfer member, toner fusion generated in the primary charging portion grows at a contact portion between the intermediate transfer member and the electrophotographic photosensitive member, and image defects such as missing halftones occur. However, stable image quality cannot be obtained.
[0007]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION An object of the present invention is to provide an electrophotographic photoreceptor which does not cause image defects due to an abnormality of the electrophotographic photoreceptor such as the above-mentioned toner fusion and filming in any environment, and has good electrophotographic characteristics even in repeated use. , An image forming apparatus and a process cartridge.
[0008]
[Means for Solving the Problems]
According to the present invention, an electrophotographic photoreceptor, a toner image forming means for forming an image on the electrophotographic photoreceptor with toner, an intermediate transfer member that moves in contact with the electrophotographic photoreceptor, Means for primary-transferring the formed toner image to the intermediate transfer member at a first transfer position of the intermediate transfer member; and a device for transferring the toner image transferred to the intermediate transfer member to a second transfer position of the intermediate transfer member. In an image forming apparatus provided with a transfer means for performing secondary transfer to a transfer material, the work of elastic deformation We of the electrophotographic photosensitive member during the indentation test to a depth of 1 μm with respect to its surface layer is the work of the entire deformation. An image forming apparatus characterized by being 45% or more with respect to Wt is provided.
[0009]
Further, according to the present invention, there is provided an electrophotographic photosensitive member provided in the image forming apparatus and a process cartridge detachable from the apparatus.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail.
[0011]
The present invention relates to an electrophotographic photosensitive member, an intermediate transfer member that moves in contact with the electrophotographic photosensitive member, and a toner image formed on the electrophotographic photosensitive member at a first transfer position of the intermediate transfer member. An image forming apparatus having a means for primary transfer to a transfer material and a transfer means for secondary transfer of a toner image transferred to the intermediate transfer body to a transfer material at a second transfer position of the intermediate transfer body. The body is characterized in that the work of elastic deformation We at the time of the indentation test to the depth of 1 μm with respect to the surface layer is 45% or more of the work Wt of the entire deformation. If the work We of elastic deformation with respect to the electrophotographic photosensitive member surface layer is less than 45%, it occurs at the contact portion between the charging member and the electrophotographic photosensitive member, and toner fusion occurs at the contact portion between the intermediate transfer member and the electrophotographic photosensitive member. They grow remarkably, resulting in image defects such as low halftone density. Preferably, the work of elastic deformation We during the indentation test to a depth of 1 μm is 47% or more and 60% or less with respect to the work Wt of the entire deformation. From the viewpoint that a suitable amount of the electrophotographic photoreceptor is shaved to cut off the fused portion, the We is preferably 60% or less.
[0012]
The indentation test of the present invention, that is, the so-called surface film property test, was performed using a hardness tester Fischerscope H100 manufactured by Fischer, Germany under an environment of 23 ° C./55% RH. In this test, it is possible to analyze the hardness of a thin film, a cured film, an organic film, and the like, and the underlying material is not particularly limited to a glass plate, an aluminum plate, an aluminum cylinder, or the like. In the measurement, using a diamond indenter whose shape is a quadrangular pyramid and the facing angle is specified at 136 °, when the set load is applied stepwise and pushed into the film, the indentation depth under the applied load Is electrically detected and read, and the hardness value H is indicated by a ratio obtained by dividing a test load by a surface area of an indentation generated by the test load. The universal hardness value HU is represented by a hardness value at the set maximum indentation depth.
[0013]
FIG. 1 shows an example when measured with a hardness meter. Point A is the measurement start point. A → B is a curve corresponding to the pressing of the indenter, and point B is a point when the maximum set pressing depth is reached. FIG. 1 shows an example in which the depth reaches 3 μm, but in the present invention, the maximum set pressing depth is set to 1 μm. The curve B → C is a curve corresponding to “return” after the indenter is pushed. Point D is the point of intersection with the horizontal axis when a perpendicular is drawn from point B to the horizontal axis. In this figure, the area surrounded by the curve AB, the straight line BD, and the horizontal axis corresponds to the total work Wt in the pressing. Similarly, the area of the portion surrounded by the curve BC, the straight line BD, and the horizontal axis corresponds to the elastic deformation work amount We.
[0014]
In the image forming apparatus of the present invention, in order to improve the transfer efficiency of the toner image from the photosensitive drum to the intermediate transfer belt, the photosensitive member and the intermediate transfer member preferably have a peripheral speed difference. When the linear velocity is Vd and the linear velocity of the intermediate transfer member is Vi, it is preferable to satisfy the following relational expression;
100.1 ≦ (Vd / Vi) × 100 ≦ 100.5
Or, 100.1 ≦ (Vi / Vd) × 100 ≦ 100.5
[0015]
Even more preferably the following ranges:
100.1 ≦ (Vd / Vi) × 100 ≦ 100.3
Or, 100.1 ≦ (Vi / Vd) × 100 ≦ 100.3
[0016]
FIG. 2 is a schematic configuration diagram of an example of an image forming apparatus according to the present invention. The image forming apparatus of this embodiment is a laser beam printer using a transfer type electrophotographic process, a contact charging type, a reversal developing type, and a maximum sheet passing size of A3 size.
[0017]
When an intermediate transfer belt is manufactured as the intermediate transfer member of the present invention, the intermediate transfer belt can be made of one or more layers of resin. Further, a structure in which a resin layer is provided on a rubber layer can also be employed.
[0018]
From the viewpoint of cost, it is preferable that the intermediate transfer belt is made of resin. Specifically, a thermoplastic resin and optional additives (such as a conductive agent, an antioxidant, a light stabilizer, a hydrolysis inhibitor and a flame retardant) are melt-kneaded and extruded from an annular die to form a joint. It is preferable to continuously produce a resin tube having no toner and cut it into an arbitrary length to produce an intermediate transfer belt. Of course, the belt may be manufactured from a thermosetting resin by centrifugal molding or dipping.
[0019]
When the intermediate transfer belt is made of rubber, the rubber layer is preferably reinforced with fibers in order to improve durability, and the rubber layer is reinforced with a woven fabric composed of vertical and horizontal threads, or a spiral thread is provided. This can reinforce the rubber layer. What is easier to manufacture is an intermediate transfer belt in which a rubber layer is reinforced by providing a spiral thread. The fiber material is preferably cotton or polyester fiber from the viewpoint of strength and cost. However, it is not limited to this. The yarn may be a single filament, a twist of a plurality of filaments, or a blended yarn. Similarly, as the woven fabric, any woven fabric such as a knitted woven fabric can be used, and of course, a woven fabric that is interwoven can also be used.
[0020]
The thickness of the rubber is preferably 0.5 mm to 2 mm, more preferably 0.5 to 1 mm. It is difficult to make the rubber belt thinner than 0.5 mm, and if it is thicker than 2 mm, smooth driving of the transfer / conveying belt becomes difficult. Further, it is more preferable that the hardness of the rubber layer is 85 ° or less, since a hollow image hardly occurs. However, the hardness is in accordance with the A-type hardness described in JIS-K6301.
[0021]
Regarding the intermediate transfer belt of the present invention, regardless of the material, the tensile elastic modulus in the circumferential direction of the intermediate transfer belt is preferably 50 MPa or more, particularly preferably 200 MPa or more, and more preferably 1 GPa or more. Since the elongation (extending on the pulling side) generated during the rotation of the transfer belt is reduced, the color misregistration is more preferably reduced.
[0022]
In producing the intermediate transfer belt of the present invention, rubber, elastomer, resin, or the like can be used.
[0023]
Rubbers and elastomers include isoprene rubber, styrene-butadiene rubber, butadiene rubber, butyl rubber, ethylene-propylene rubber, ethylene-propylene terpolymer, chloroprene rubber, chlorosulfonated polyethylene, chlorinated polyethylene, acrylonitrile butadiene rubber, urethane rubber, Octamatic 1,2-polybutadiene, epichlorohydrin rubber, acrylic rubber, silicone rubber, hydrogenated nitrile rubber, and thermoplastic elastomers (for example, polystyrene, polyolefin, polyvinyl chloride, polyurethane, polyamide, and polyester) Etc. can be used. However, the material is not limited to the above.
[0024]
As the resin, vinyl acetate, polyester, polyarylate, polysulfone, polyether sulfone, polyethylene terephthalate, polybutylene terephthalate, polycarbonate, polyethylene, polypropylene, polybutadiene, polyvinylidene chloride, ionomer resin, polyurethane, silicone resin, fluorine resin , Polyamide, aromatic polyamide, modified polyphenylene oxide, polystyrene, and the like. However, the material is not limited to the above.
[0025]
However, in the intermediate transfer belt of the present invention, it is preferable that at least the main component of the surface layer is a resin. This is because if the main component of the surface layer is a rubber or an elastomer, the adhesiveness of the surface of the transfer / conveying belt increases, and once toner adheres to the belt, it is not easy to remove the toner. The toner adhering to the belt adheres to the back side of the transfer material and causes back stains. In severe cases, the resistance value in the thickness direction of the transfer conveyance belt becomes too large, making it difficult for the transfer current to flow, and the transfer efficiency. , That is, image quality is likely to be reduced.
[0026]
A conductive agent can be added to the intermediate transfer belt in the present invention. Any conductive agent may be used, for example, carbon, metal powder such as aluminum and nickel, metal oxide such as titanium oxide, quaternary ammonium salt-containing polymethyl methacrylate, polyvinyl aniline, polyvinyl pyrrole, Examples include conductive polymer compounds such as polydiacetylene, polyethyleneimine, boron-containing polymer compounds, and polypyrrole. However, it is not limited to the above conductive agent.
[0027]
The intermediate transfer belt according to the present invention may be a single layer or a plurality of layers. Further, the resistance value of the intermediate transfer belt is not limited, but is, for example, about 10 ⁵ to 10 ¹⁴ Ω · cm in volume resistivity and about 10 ⁶ to 10 ¹⁶ Ω / □ in surface resistivity.
[0028]
When the resistance value is out of the above range, toner fusion becomes more remarkable. For example, if the volume low efficiency exceeds 10 ¹⁴ , inadvertent discharge is caused everywhere, and toner fusion is further deteriorated in the same manner as toner fusion occurs at the contact portion between the primary charging member and the electrophotographic photosensitive member. I do. That is, when the resistance value of the intermediate transfer member is within the above range and the elastic deformation rate of the electrophotographic photosensitive member is 45% or more, the fusion is further improved.
[0029]
The volume resistivity and the surface resistivity are measured as follows.
[0030]
<Measuring machine>
Resistance meter: Ultra high resistance meter R8340A (manufactured by Advantest)
Sample box: sample box TR42 for ultra-high resistance measurement (manufactured by Advantest Co.) However, the main electrode has a diameter of 22 mm, the guard ring electrode has an inner diameter of 41 mm, and an outer diameter of 49 mm.
[0031]
<Sample> The intermediate transfer member is cut into a circle having a diameter of 56 mm. After cutting, one surface is provided with electrodes on the entire surface by a Pt-Pd vapor-deposited film, and the other surface is provided by a Pt-Pd vapor-deposited film on a main electrode having a diameter of 25 mm and a guard ring electrode having an inner diameter of 38 mm and an outer diameter of 50 mm. The Pt-Pd vapor-deposited film can be obtained by performing a vapor-deposition operation with mild sputter E1030 (manufactured by Hitachi, Ltd.) for 2 minutes. The sample after the vapor deposition operation is used as a measurement sample.
[0032]
<Measurement conditions>
Measurement atmosphere: 23 ° C / 50-60%. The measurement sample is left in an atmosphere of 23 ° C./50 to 60% for 12 hours or more.
[0033]
Measurement mode; program mode 5
(Discharge 10 seconds, charge and measure 30 seconds)
Applied voltage: 100 (V)
[0034]
The contact angle of the surface layer of the intermediate transfer member with water in the present invention is preferably 50 ° to 120 °, and more preferably 60 ° to 110 °. If the contact angle is smaller than 50 °, the secondary transfer efficiency may decrease. In particular, in a high-temperature and high-humidity environment, the amount of water adsorbed on the surface of the intermediate transfer member increases, so that the secondary transfer efficiency tends to decrease and the cleaning performance tends to deteriorate, and toner fusion may occur significantly. is there.
[0035]
On the other hand, if the contact angle is larger than 120 °, slip tends to occur at the contact portion between the intermediate transfer member and the electrophotographic photosensitive member, and streaks at regular intervals called banding occur on the image in the direction of the electrophotographic photosensitive member bus line. Sometimes. It also becomes difficult to manufacture.
[0036]
When the contact angle of water with the surface layer of the intermediate transfer member is within the above range and the elastic deformation rate of the electrophotographic photosensitive member is 45% or more, the fusion is further improved.
[0037]
The contact angle can be obtained by measuring the value 10 seconds after dropping the water droplet using a goniometer-type contact angle measuring device (manufactured by Kyowa Interface Science Co., Ltd.). The water used here uses distilled water.
[0038]
The surface roughness Rz of the intermediate transfer member is preferably in the range of 0.1 μm to 8 μm. If the surface roughness Rz of the intermediate transfer member exceeds 8 μm, the adhesion and fusion of the toner are promoted by the unevenness of the surface, and the life of the intermediate transfer member is easily reduced. Further, when Rz is less than 0.1 μm, adhesion tends to occur between the electrophotographic photosensitive member and the image immediately after startup when left for a long time at a high temperature in contact with the electrophotographic photosensitive member. Image defects such as streaks tend to occur.
[0039]
The surface roughness was averaged by measuring a point 30 mm from both ends of the intermediate transfer member and three points at the center with a surf coder SE3300 (manufactured by Kosaka Laboratories) at a length of 2.5 mm.
[0040]
Next, the electrophotographic photosensitive member of the present invention will be described in detail.
[0041]
The layer constitution of the electrophotographic photoreceptor in the present invention comprises a layer constitution having a photosensitive layer consisting of a single layer containing a charge generating material and a charge transporting material simultaneously on a conductive support, and a charge generating material on a conductive support. And a charge transporting layer containing a charge transporting material.
[0042]
FIG. 3 shows a layer structure having a photosensitive layer in which a charge generation layer containing a charge generation material and a charge transport layer containing a charge transport material are laminated on a conductive support. A conductive layer 1a for suppressing interference of light and improving the adhesiveness of an upper layer, a subbing layer 1b for preventing charge injection from the support, a photocharge generating layer 1c, It has a configuration in which four layers of the transport layer 1d are sequentially painted from the bottom.
[0043]
Examples of effective charge generation materials used in the present invention include the following substances. These charge generation materials may be used alone or in combination of two or more.
[0044]
(1) Azo pigments such as monoazo, bisazo and trisazo (2) Indigo pigments such as indigo and thioindigo (3) Phthalocyanine such as metal phthalocyanine and nonmetal phthalocyanine (4) Perylene anhydride and perylene imide Perylene pigments (5) polycyclic quinone pigments such as anthraquinone and pyrenequinone (6) squarylium dyes (7) pyrylium salts and thiopyrylium salts (8) triphenylmethane dyes (9) inorganic materials such as selenium and amorphous silicon Substance [0045]
The layer containing the charge generating material, that is, the charge generating layer, can be formed by dispersing the above-described charge generating material in a suitable binder and applying the resultant onto a conductive support. Further, it can also be formed by forming a thin film on a conductive support by a dry method such as vapor deposition, sputtering and CVD.
[0046]
The binder can be selected from a wide range of binder resins, for example, polycarbonate resin, polyester resin, butyral resin, polystyrene resin, polyvinyl acetal resin, diallyl phthalate resin, acrylic resin, methacrylic resin, vinyl acetate resin, phenol Examples include, but are not limited to, resins, silicone resins, polysulfone resins, styrene-butadiene copolymer resins, alkyd resins, epoxy resins, urea resins, and vinyl chloride-vinyl acetate copolymer resins. These may be used alone or as a copolymer polymer alone or as a mixture of two or more.
[0047]
The amount of the resin contained in the charge generation layer is preferably 80% by mass or less, and particularly preferably 40% by mass or less. The thickness of the charge generation layer is preferably 5 μm or less, and particularly preferably a thin film layer having a thickness of 0.01 μm to 2 μm. Various sensitizers may be added to the charge generation layer.
[0048]
The layer containing the charge transporting material, that is, the charge transporting layer, can be formed by combining the charge transporting material with an appropriate binder (binding resin). Examples of the binder used in the charge transport layer include those used in the charge generation layer, and polycarbonate resins and polyarylate resins having excellent abrasion resistance and electrical properties are preferable. Further, it is preferable to contain a silicone-modified polycarbonate resin from the viewpoint of improving toner fusion.
[0049]
As the charge transport material, one type may be used alone, or two or more types may be used in combination. Charge transport materials having other structures (eg, polycyclic aromatic compounds such as pyrene and anthracene, carbazole-based, indole-based, and oxazole-based materials) Heterocyclic compounds such as thiazole-based, oxadiazole-based, pyrazole-based, pyrazoline-based, thiadiazole-based and riazole-based compounds, triarylmethane-based compounds, or polymers having a group consisting of these compounds in the main chain or side chain ( For example, poly-N-vinylcarbazole, polyvinylanthracene, etc.)].
[0050]
The charge transport layer is electrically connected to the above-described charge generation layer, and has a function of receiving charge carriers injected from the charge generation layer in the presence of an electric field and transporting these charge carriers to the surface. ing. Since the charge transport layer has a limit for transporting charge carriers, it is impossible to increase the film thickness more than necessary. However, the thickness is preferably 5 μm to 40 μm, and particularly preferably 10 μm to 30 μm.
[0051]
When forming such a charge transport layer, using an appropriate organic solvent, using a coating method such as dip coating method, spray coating method, spinner coating method, roller coating method, Meyer bar coating method and blade coating method. It can be carried out.
[0052]
【Example】
Hereinafter, the present invention will be described in more detail with reference to specific examples. In addition, "part" in an Example means a mass part.
[0053]
(Example 1)
100 parts of polycarbonate resin and 12 parts of carbon black are melt-kneaded, and a seamless resin tube having a thickness of 150 μm and a volume resistivity of 7 × 10 ⁸ Ω · cm is obtained by inflation molding, and cut into a predetermined width. After that, an end portion reinforcing tape and a rib were attached to produce a resin belt, and an intermediate transfer belt was obtained. The contact angle of the obtained intermediate transfer belt surface with water was 100 °, and the surface roughness Rz was 0.98 μm.
[0054]
50 parts of titanium oxide powder coated with tin oxide containing 10% antimony oxide, 25 parts of resole type phenol resin, 20 parts of methyl cellosolve, 5 parts of methanol and silicone oil (polydimethylsiloxane / polyoxyalkylene copolymer, 0.002 parts of an average molecular weight of 3000) was dispersed in a sand mill using 1 mmφ glass beads for 2 hours to prepare a coating for a conductive layer. A coating for a conductive layer was dip-coated on an aluminum cylinder (φ30 mm), and dried at 140 ° C. for 30 minutes to form a conductive layer having a thickness of 20 μm.
[0055]
A solution obtained by dissolving 5 parts of a 6-66-610-12 quaternary polyamide copolymer in a mixed solvent of 70 parts of methanol / 25 parts of butanol in a mixed solvent is applied onto the conductive layer by dip coating, followed by drying. A layer (charge injection blocking layer) was formed.
[0056]
Next, 3.5 parts of hydroxygallium phthalocyanine crystal having strong peaks at 7.4 ° and 28.2 ° of Bragg angles (2θ ± 0.2 °) in characteristic X-ray diffraction of CuKα and polyvinyl butyral resin (trade name) : SREC BH-S, manufactured by Sekisui Chemical Co., Ltd.) 1 part was added to 120 parts of cyclohexanone, dispersed by a sand mill using 1 mmφ glass beads for 3 hours, and diluted with 120 parts of methyl ethyl ketone for charge generation layer. A paint was prepared. On the undercoat layer, this charge generation layer paint was applied by dip coating, and dried at 100 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.15 μm.
[0057]
Next, 10 parts of a compound represented by the following formula (A) as a charge transport material:
[0058]
Embedded image

10 parts of a polyarylate resin represented by a structural unit represented by the following formula (B):
[0059]
Embedded image

It was dissolved in a mixed solvent of 50 parts of monochlorobenzene / 10 parts of dichloromethane. This paint was applied on the above-mentioned charge generation layer by a dipping method, and dried at 110 ° C. for 1 hour to form a charge transport layer having a thickness of 23 μm.
[0060]
The work of elastic deformation We of the electrophotographic photoreceptor thus manufactured in a surface indentation test was 46.8% of Wt. The electrophotographic photoreceptor was mounted on the image forming apparatus shown in FIG. 2 equipped with an intermediate transfer belt, subjected to continuous 20,000-sheet running, and visually evaluated. The peripheral speed difference between the electrophotographic photosensitive member and the intermediate transfer member of this apparatus is 101%. Table 1 shows the image evaluation results.
[0061]
(Example 2)
In Example 1, a polyarylate resin represented by a structural unit represented by the following formula (C) instead of the formula (B):
Embedded image

Was prepared in the same manner as in Example 1 except that 10 parts of was used. The work of elastic deformation We of the electrophotographic photosensitive member was 48.8%. This electrophotographic photoreceptor was mounted on the above-mentioned image forming apparatus, and continuous running of 20,000 sheets was performed, and the image was evaluated visually. Table 1 shows the results.
[0063]
(Example 3)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the charge transporting material (A) was changed to 7 parts. The work of elastic deformation We of the electrophotographic photosensitive member was 50.5%. This electrophotographic photoreceptor was mounted on the above-mentioned image forming apparatus, and continuous running of 20,000 sheets was performed, and the image was evaluated visually. Table 1 shows the results.
[0064]
(Example 4)
2 parts of the charge transporting material (A) and a charge transporting material represented by the following formula (D)
Embedded image

The electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the amount was changed to 8 parts. The work of elastic deformation We of the electrophotographic photosensitive member was 46.5%. This electrophotographic photoreceptor was mounted on the above-mentioned image forming apparatus, and continuous running of 20,000 sheets was performed, and the image was evaluated visually. Table 1 shows the results.
[0066]
(Example 5)
The intermediate transfer belt of Example 1 was polished with # 2000 water-resistant abrasive paper to form an intermediate transfer belt having a contact angle of 115 ° with water on the belt surface and an Rz of 1.25 μm. The intermediate transfer belt was mounted on the image forming apparatus shown in FIG. 2, and the electrophotographic photosensitive member was subjected to continuous running of 20,000 sheets using the electrophotographic photosensitive member described in Example 1, and the image was evaluated visually. Was done. The results are shown in Table 1.
[0067]
(Example 6)
Instead of the image forming apparatus using the intermediate transfer member shown in FIG. 2, 20,000 continuous sheets are continuously formed using an image forming apparatus using a method of directly transferring a developer on an electrophotographic photosensitive member to a transfer material on a transport belt. Paper passing durability was evaluated, and image evaluation was performed visually. The results are shown in Table 1.
[0068]
(Comparative Example 1)
An electrophotographic photosensitive member was produced in the same manner as in Example 1, except that 10 parts of a bisphenol A-type polycarbonate resin was used instead of the polyarylate resin represented by the formula (B). The work of elastic deformation We of the electrophotographic photosensitive member was 43.2%.
This electrophotographic photoreceptor was mounted on the above-mentioned image forming apparatus, and continuous running of 20,000 sheets was performed, and the image was evaluated visually. Table 1 shows the results.
[0069]
(Comparative Example 2)
An electrophotographic photosensitive member was produced in the same manner as in Example 1, except that the charge transporting material (A) was changed to 30 parts. The work of elastic deformation We of the electrophotographic photosensitive member was 41.8%. This electrophotographic photoreceptor was mounted on the above-mentioned image forming apparatus, and continuous running of 20,000 sheets was performed, and the image was evaluated visually. Table 1 shows the results.
[0070]
(Comparative Example 3)
An electrophotographic photosensitive member was produced in the same manner as in Example 1, except that the polyarylate resin represented by the formula (B) was changed to 5 parts. The work of elastic deformation We of the electrophotographic photosensitive member was 42.9%. The electrophotographic photoreceptor was mounted on the above-mentioned image forming apparatus, subjected to continuous running of 20,000 sheets, and visually evaluated. Table 1 shows the results.
[0071]
[Table 1]

[0072]
【The invention's effect】
As described above, according to the present invention, the intermediate transfer member that moves in contact with the electrophotographic photosensitive member, and the toner image formed on the electrophotographic photosensitive member is transferred to the intermediate transfer member at the first transfer position of the intermediate transfer member. Regarding an image forming apparatus having a means for primary transfer to a transfer body and a transfer means for secondary transfer of a toner image transferred to the intermediate transfer body to a transfer material at a second transfer position of the intermediate transfer body, By preventing toner fusion and filming to the photoreceptor, it has become possible to provide an image forming apparatus and a process cartridge capable of obtaining a good and stable image.
[Brief description of the drawings]
FIG. 1 is an example of a measurement chart in a Fischer hardness tester.
FIG. 2 is a diagram illustrating a schematic configuration of a full-color image forming apparatus having a plurality of electrophotographic photosensitive members.
FIG. 3 is a diagram illustrating a layer configuration of an electrophotographic photosensitive member and a charging roller.
[Explanation of symbols]
Reference Signs List 1 photosensitive drum 1a conductive layer 1b undercoat layer 1c charge generation layer 1d charge transport layer 2 primary charger (charging roller)
2a cored bar 2b lower layer 2c intermediate layer 2d surface layer 2e pressing spring 2f charging roller cleaning member 2g support member 3 exposure light 10 transfer material guide 11 paper feed roller 13 photosensitive drum cleaning device 15 fixing device 16 intermediate transfer body cleaning device 20 Intermediate transfer belt 28 Bias power supply 41 Yellow developing device 42 Magenta developing device 43 Cyan developing device 44 Black developing device 62 Primary transfer roller 63 Secondary transfer roller 64 Secondary transfer facing roller 67 Static eliminator P Transfer material

Claims (6)

An electrophotographic photosensitive member, a toner image forming unit for forming an image on the electrophotographic photosensitive member with toner, an intermediate transfer member that moves in contact with the electrophotographic photosensitive member, and a toner formed on the electrophotographic photosensitive member Means for primary-transferring the image to the intermediate transfer member at a first transfer position of the intermediate transfer member; and transferring the toner image transferred to the intermediate transfer member to a transfer material at a second transfer position of the intermediate transfer member. In an image forming apparatus provided with a transfer unit for performing the next transfer, the work of elastic deformation We of the electrophotographic photosensitive member at the time of an indentation test to a depth of 1 μm with respect to the surface layer thereof is larger than the work Wt of the entire deformation. , 45% or more. 2. The image according to claim 1, wherein the elastic deformation work We in the indentation test of the electrophotographic photoreceptor to the surface layer to a depth of 1 μm is 47% or more of the work Wt of the entire deformation. Forming equipment. 3. The electrophotographic photosensitive member according to claim 1, wherein an elastic deformation work We in an indentation test to a depth of 1 μm with respect to a surface layer thereof is 60% or less of a work Wt of the entire deformation. 4. Image forming apparatus. 2. The image forming apparatus according to claim 1, wherein a peripheral speed difference between the electrophotographic photosensitive member and the intermediate transfer member satisfies the following expression.
100.1 ≦ (Vd / Vi) × 100 ≦ 105.0
Or, 100.1 ≦ (Vi / Vd) × 100 ≦ 105.0
(Vd: linear velocity of the drum, Vi: linear velocity of the intermediate transfer member) An electrophotographic photosensitive member used in the image forming apparatus according to claim 1. 6. The image forming apparatus according to claim 1, wherein the electrophotographic photosensitive member according to claim 5 and at least one unit selected from the group consisting of a charging unit, a developing unit, and a cleaning unit are integrally supported. A process cartridge which is detachable from a main body.

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