JP4759186B2 - Conductive endless belt and image forming apparatus - Google Patents

Description

【００３５】
以上の測定及び試験の結果より、実施例の導電性エンドレスベルトは、表面平滑性、屈曲耐久性、耐クリープ性及び画像性の点で顕著な優位性を有することが確認された。
【００３６】
【発明の効果】
以上説明してきたように、本発明によれば、高い寸法精度を有し、強度、特には屈曲耐久性、耐クリープ性及び表面平滑性に優れる導電性エンドレスベルトを提供することができる。また、かかる本発明の導電性エンドレスベルトを用いた本発明の画像形成装置によれば、長期間の使用においても不良がなく良好な画像を得ることができ、ベルトが劣化しにくい。
【図面の簡単な説明】
【図１】 本発明の一実施の形態に係る導電性エンドレスベルトの幅方向断面図である。
【図２】 本発明の画像形成装置の一例としての転写搬送ベルトを用いたタンデム方式の画像形成装置の一例を示す概略図である。
【図３】 本発明の画像形成装置の他の例としての中間転写部材を用いた中間転写方式の画像形成装置の一例を示す概略図である。
【符号の説明】
１ 感光体ドラム
２ 帯電ロール
３ 現像ロール
４ 現像ブレード
５ トナー供給ロール
６ クリーニングブレード
７ 帯電ロール
８ 除電ロール
９ 駆動ローラ（駆動部材）
１０ 転写搬送ベルト
１１ 感光体
１２ 一次帯電器
１３ 画像露光
１４，３５ クリーニング装置
１９ 給紙カセット
２０ 中間転写部材
２５ 転写ローラ
２６ 記録媒体
２９，６１ 電源
３０ 駆動ローラ
４１，４２，４３，４４ 現像器[0001]
BACKGROUND OF THE INVENTION
The present invention supplies a developer to the surface of an image forming body such as a latent image holding body holding an electrostatic latent image on the surface in an electrostatic recording process in an electrophotographic apparatus such as a copying machine or a printer, or an electrostatic recording apparatus. The present invention relates to a conductive endless belt (hereinafter also simply referred to as a “belt”) used when transferring a toner image formed in this way onto a recording medium such as paper, and an image forming apparatus using the same.
[0002]
[Prior art]
Conventionally, in an electrostatic recording process in a copying machine, a printer, etc., first, the surface of a photosensitive member (latent image holding member) is uniformly charged, and an image is projected onto the photosensitive member from an optical system and exposed to light. An electrostatic latent image is formed by erasing the charged portion, and then toner is supplied to the electrostatic latent image to form a toner image by electrostatic adhesion of the toner, which is formed on paper, OHP, photographic paper For example, a method of printing by transferring to a recording medium such as the above is employed.
In this case, color printers and color copiers basically print according to the above process, but in the case of color printing, the color tone is reproduced using toners of four colors, magenta, yellow, cyan, and black. Therefore, a process for obtaining a necessary color tone by superimposing these toners at a predetermined ratio is required, and several methods have been proposed for performing this process.
[0003]
First, as in the case of monochrome printing, when the electrostatic latent image is visualized by supplying toner onto the photosensitive member, the four colors of magenta, yellow, cyan, and black are sequentially added. There is a multi-development system in which development is performed by superimposing and a color toner image is formed on the photoreceptor. According to this method, it is possible to configure the apparatus relatively compactly, but this method has a problem in that it is very difficult to control gradation and high image quality cannot be obtained.
Second, four photosensitive drums are provided, and the latent images on each drum are developed with magenta, yellow, cyan, and black toners, respectively, so that a magenta toner image, a yellow toner image, a cyan toner image, and a black toner image are obtained. By forming four toner images of the toner image, arranging the photosensitive drums on which these toner images are formed in a line, sequentially transferring the toner images onto a recording medium such as paper, and superimposing them on the recording medium, a color image is formed. There is a tandem method to reproduce. Although this method can obtain a good image, the four photosensitive drums, the charging mechanism and the developing mechanism provided for each photosensitive drum are arranged in a line, and the apparatus becomes large and expensive. It becomes.
[0004]
FIG. 2 shows a configuration example of the printing unit of the tandem image forming apparatus. A printing unit composed of the photosensitive drum 1, the charging roll 2, the developing roll 3, the developing blade 4, the toner supply roll 5, and the cleaning blade 6 corresponds to the yellow Y, magenta M, cyan C, and black B toners 4. The toner images are sequentially transferred onto a sheet that is circulated by a driving roller (driving member) 9 and conveyed by a transfer conveying belt 10 to form a color image. Charging and discharging of the transfer / conveying belt are performed by the charging roll 7 and the discharging roll 8, respectively. Further, a suction roller (not shown) is used for charging the paper for sucking the paper onto the belt. Owing to these measures, generation of ozone can be suppressed. The suction roller places the paper on the transfer conveyance belt from the conveyance path and performs electrostatic adsorption on the transfer conveyance belt. Further, the sheet separation after the transfer can be performed only by the curvature separation by lowering the transfer voltage to weaken the adsorption force between the sheet and the transfer conveyance belt.
[0005]
As materials for the transfer / conveyance belt 10, there are a resistor and a dielectric, each having advantages and disadvantages. Since the resistor belt can hold charges for a short time, when it is used for tandem transfer, there is little charge injection during transfer, and the voltage rise is relatively small even during continuous transfer of four colors. In addition, when it is repeatedly used for the transfer of the next sheet, the electric charge is released, and no electrical reset is required. However, since the resistance value changes due to environmental fluctuations, there are disadvantages such as affecting transfer efficiency and being easily influenced by the thickness and width of the paper.
On the other hand, in the case of a dielectric belt, there is no spontaneous release of injected charge, and both charge injection and discharge must be electrically controlled. However, since the charge is stably held, the sheet can be adsorbed reliably and can be conveyed with high accuracy. Since the dielectric constant is less dependent on temperature and humidity, the transfer process is relatively stable to the environment. The drawback is that the transfer voltage increases because charges are accumulated on the belt each time the transfer is repeated.
[0006]
Thirdly, a recording medium such as paper is wound around a transfer drum, and this is rotated four times, and magenta, yellow, cyan, and black on the photosensitive member are sequentially transferred to the recording medium every rotation to reproduce a color image. There is also a method. According to this method, a relatively high image quality can be obtained. However, when the recording medium is a cardboard such as a postcard, it is difficult to wind the recording medium around the transfer drum, and the type of the recording medium is limited. There is.
[0007]
A system in which good image quality is obtained with respect to the multiple development system, tandem system and transfer drum system, the apparatus is not particularly large, and the type of recording medium is not particularly limited. As an example, an intermediate transfer method has been proposed.
That is, in this intermediate transfer system, an intermediate transfer member composed of a drum or a belt for temporarily transferring and holding the toner image on the photosensitive member is provided, and a magenta toner image, a yellow toner image, and a cyan toner are provided around the intermediate transfer member. By arranging four photoreceptors on which an image and a black toner image are formed and sequentially transferring the four color toner images onto the intermediate transfer member, a color image is formed on the intermediate transfer member. The image is transferred onto a recording medium such as paper. Therefore, since the gradation is adjusted by superimposing the four color toner images, it is possible to obtain high image quality, and it is not necessary to arrange the photoconductors in a row as in the tandem method, so that the apparatus can be used. There is no particular increase in size, and there is no need to wrap the recording medium around the drum, so the type of recording medium is not limited. There is also a tandem intermediate transfer method that combines a tandem method and an intermediate transfer method.
As an apparatus for forming a color image by the intermediate transfer method, an image forming apparatus using an endless belt-shaped intermediate transfer member as an intermediate transfer member is illustrated in FIG.
[0008]
In FIG. 3, reference numeral 11 denotes a drum-shaped photoconductor, which rotates in the direction of the arrow in the figure. The photosensitive member 11 is charged by the primary charger 12, and then the charged portion of the exposed portion is erased by image exposure 13, and an electrostatic latent image corresponding to the first color component is formed on the photosensitive member 11. The electrostatic latent image is developed with the first color magenta toner M by the developing device 41, and a first color magenta toner image is formed on the photoreceptor 11. Next, the toner image is circulated and driven by a driving roller (driving member) 30 and transferred to the intermediate transfer member 20 that circulates and rotates while contacting the photoreceptor 11. In this case, transfer from the photoconductor 11 to the intermediate transfer member 20 is performed by a primary transfer bias applied from the power source 61 to the intermediate transfer member 20 at the nip portion between the photoconductor 11 and the intermediate transfer member 20. After the first color magenta toner image is transferred to the intermediate transfer member 20, the surface of the photoconductor 11 is cleaned by the cleaning device 14, and the development transfer operation for the first rotation of the photoconductor 11 is completed. Thereafter, the photoconductor rotates three times, and the second color cyan toner image, the third color yellow toner image, and the fourth color black toner image are sequentially used by the developing units 42 to 44 for each turn. The toner image is formed on the intermediate transfer member 20 and is superimposed and transferred to the intermediate transfer member 20 every round, so that a composite color toner image corresponding to the target color image is formed on the intermediate transfer member 20. In the apparatus of FIG. 3, the developing devices 41 to 44 are sequentially replaced with each rotation of the photoreceptor 11 so that development with magenta toner M, cyan toner C, yellow toner Y, and black toner B is sequentially performed. It has become.
[0009]
Next, the transfer roller 25 contacts the intermediate transfer member 20 on which the composite color toner image is formed, and a recording medium 26 such as paper is fed from the paper feed cassette 19 to the nip portion. At the same time, a secondary transfer bias is applied from the power source 29 to the transfer roller 25, and the composite color toner image is transferred from the intermediate transfer member 20 onto the recording medium 26 and heated and fixed to form a final image. After the composite color toner image is transferred to the recording medium 26, the transfer residual toner on the surface is removed by the cleaning device 35, and the intermediate transfer member 20 returns to the initial state to prepare for the next image formation.
Conventionally, as the endless belt-shaped intermediate transfer member 20, a semiconductive resin film belt and a rubber belt having a fiber reinforcement are mainly used. Among these, as semiconductive resin film belts, those obtained by blending carbon black with polycarbonate have been known, but recently, polyalkylene terephthalate has been improved based on the durability in terms of bending. Resin film belts as materials (Japanese Patent Laid-Open No. 8-99374) and resin film belts based on thermoplastic polyimide with improved elasticity (Japanese Patent Laid-Open No. 11-170389) have been proposed. Yes.
[0010]
[Problems to be solved by the invention]
In tandem, intermediate transfer, and tandem intermediate transfer type image forming devices that use conductive endless belts, all of them have the strength to withstand continuous use over the conductive endless belt, especially bending durability, Creep resistance and smoothness of the belt surface are required.
[0011]
Accordingly, an object of the present invention is to provide a resin film belt for use in an image forming apparatus of a tandem system, an intermediate transfer system, and a tandem intermediate transfer system, and has a good strength, particularly a good bending durability and creep resistance, and further a surface An object is to provide a conductive endless belt having smoothness and an image forming apparatus using the same.
[0012]
[Means for Solving the Problems]
As a result of intensive studies on various synthetic resins to solve the above-mentioned problems, the present inventor can achieve the above object by using a mixture of a thermoplastic resin and whisker as a base material of a conductive endless belt. As a result, the present invention has been completed. That is, the present invention is as follows.
[0013]
(1). The recording medium held by electrostatic attraction is circulated and driven by a driving member, transported to four types of image forming bodies, and tandem transfer and / or transporting conductivity for sequentially transferring each toner image to the recording medium. In the endless belt,
A conductive endless belt comprising a mixture of a thermoplastic resin and whisker (a fibrous inorganic compound and / or metal particles having an aspect ratio of 10 or more) as a base material.
(2). The toner image formed between the image forming body and the recording medium is circulated and driven by a driving member, and the toner image formed on the surface of the image forming body is once transferred and held on the surface of the image forming body and transferred to the recording medium. In the conductive endless belt for intermediate transfer member,
A conductive endless belt comprising a mixture of a thermoplastic resin and whisker (a fibrous inorganic compound and / or metal particles having an aspect ratio of 10 or more) as a base material.
(3). The conductive endless belt according to (1) or (2), wherein the ratio of the whisker component in the mixture is 5 to 50% by weight.
(4). The conductive endless belt according to (1) or (2), wherein the whisker has an average long-axis fiber length of 0.2 to 40 μm.
(5). The whisker is calcium silicate hydrate (Ca ₆ (Si ₆ 0 ₁₇ ) (OH) ₂ ) In an amount of 90% by weight or more as a main component. The conductive endless belt according to the above (1) or (2).
(6). The conductive endless belt according to (1) or (2), wherein the thermoplastic resin contains polyamide 12.
(7). An image forming apparatus using the conductive endless belt according to any one of (1) and (2).
[0014]
The conductive endless belt of the present invention described above has good strength, particularly good bending durability and creep resistance, and has high smoothness on the belt surface. In addition, when a fitting portion that fits the drive member and the conductive endless belt is provided, the phenomenon that the conductive endless belt stretched around two or more shafts is displaced in the width direction as it rotates is prevented. can do. Further, according to the image forming apparatus of the present invention, it is possible to provide a good image without causing a defect even when used for a long period of time.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail.
In general, the conductive endless belt includes a jointed belt and a jointless belt (so-called seamless belt), but any one may be used in the present invention. As described above, the conductive endless belt of the present invention can be used as a transfer member for a tandem system, an intermediate transfer system, and a tandem intermediate transfer system.
When the conductive endless belt of the present invention is, for example, a transfer conveyance belt indicated by reference numeral 10 in FIG. 2, the toner is sequentially driven on a recording medium that is driven by a driving member such as a driving roller 9 and is conveyed accordingly. Transferred to form a color image.
[0016]
Further, when the conductive endless belt of the present invention is an intermediate transfer member indicated by reference numeral 20 in FIG. 3, for example, this is circulated by a driving member such as a driving roller 30 and the photosensitive drum (latent image holding member). ) 11 and the recording medium 26 such as paper, the toner image formed on the surface of the photosensitive drum 11 is temporarily transferred and held, and then transferred to the recording medium 26. Note that the apparatus of FIG. 3 performs color printing by the intermediate transfer method as described above.
[0017]
In the mixture of the thermoplastic resin and whisker constituting the base material of the conductive endless belt of the present invention, the ratio of the whisker component is preferably 5 to 50% by weight, and more preferably 10 to 30% by weight. If the ratio of the whisker component is less than 5% by weight, sufficient bending resistance and creep resistance may not be obtained, and if it exceeds 50% by weight, the smoothness of the belt surface may be impaired.
[0018]
The thermoplastic resin is not particularly limited and may be a commercially available one. For example, polyamide 12, acrylonitrile-butadiene-styrene, acrylonitrile-ethylenepropylene-styrene, polyamide 6, polyamide 66, polyacetal, polymethyl methacrylate, polyfluoride. Vinylidene fluoride, polyvinyl fluoride, polyhexafluoroethylene propylene, polytrifluoride ethylene, poly (ethylene-tetrafluoroethylene), polyacrylonitrile, polyarylate, polybutylene terephthalate, polycarbonate, polyether ether ketone, polyetherimide, Examples include polyethersulfone, polyethylene, polyethylene terephthalate, polystyrene, polyphenylene oxide, polysulfone, and polyarylate. Amides 12 and acrylonitrile - butadiene - styrene are preferred, polyamide 12 is more preferred.
[0019]
Further, the main component of whisker is not particularly limited, and a commercially available product may be used. For example, calcium silicate hydrate whisker (Ca ₆ ・ Si ₆ O ₁₇ ・ (OH) ₂ ), Basic magnesium hydroxide hydrate whisker (MgSO _Four ・ 5Mg (OH) ₂ ・ 3H ₂ O), potassium titanate whisker (K ₂ O · 6TiO ₂ And K ₂ O · 8TiO ₂ ), Aluminum borate whisker, potassium titanate whisker, carbon whisker, graphite whisker, titanium carbide whisker, conductive potassium titanate whisker, conductive barium titanate whisker, conductive titanium oxide whisker, wollastonite whisker, sepiolite whisker, Examples include aluminum borate whisker, alumina whisker, chromium whisker, copper whisker, iron whisker, nickel whisker, silicon carbide whisker, silicon nitride whisker, zinc oxide whisker and calcium carbonate whisker, calcium silicate hydrate whisker, basic Magnesium hydroxide hydrate whisker and potassium titanate whisker are preferred, and calcium silicate hydrate whisker is more preferred. The whisker preferably contains 90% by weight or more of these components, and more preferably 75% by weight or more.
The whisker preferably has an average long axis fiber length of 0.2 to 40 μm, and more preferably 0.4 to 20.
[0020]
Further, the mixture of the thermoplastic resin and whisker can be imparted or adjusted by adding a conductive material as a functional component. In this case, the conductive material is not particularly limited. Lauryltrimethylammonium, stearyltrimethylammonium, octadecyltrimethylammonium, dodecyltrimethylammonium, hexadecyltrimethylammonium, modified fatty acid / dimethylethylammonium perchlorate, chlorate , Cationic surfactants such as quaternary ammonium such as borofluoride, sulfate, ethosulphate salt, benzyl halide salt (benzyl bromide salt, benzyl chloride salt, etc.); aliphatic sulfonic acid, higher alcohol Anionic surfactants such as sulfate ester salts, higher alcohol ethylene oxide addition sulfate salts, higher alcohol phosphate ester salts; amphoteric surfactants such as various betaines; higher alcohol ethylene oxides, polyethylene glycols Fatty acid esters, polyhydric antistatic agent such as a nonionic antistatic agents such as alcohol fatty acid ester, LiCF ₂ SO ₂ , NaClO _Four , LiBF _Four , NaCl and other group 1 metal salts of the periodic table; Ca (ClO _Four ) ₂ Group 2 metal salts of the periodic table, etc .: and those antistatic agents having one or more groups having an active hydrogen that reacts with isocyanate (hydrogen group, carboxyl group, primary to secondary amine group, etc.), etc. Is mentioned. Furthermore, a complex of these with a polyhydric alcohol (1,4-butanediol, ethylene glycol, polyethylene glycol, propylene glycol, etc.) or a derivative thereof, or a complex with ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, etc. Ion conductive agent; conductive carbon such as ketjen black and acetylene black; carbon for rubber such as SAF, ISAF, HAF, FEF, GPF, SRF, FT, and MT; carbon for color ink subjected to oxidation treatment, pyrolytic carbon And natural graphite, artificial graphite and the like; metals and metal oxides such as tin oxide, titanium oxide, zinc oxide, nickel and copper; and conductive polymers such as polyaniline, polypyrrole and polyacetylene.
[0021]
When the conductive material is carbon black, the amount of these conductive materials added to the substrate is 0.1 to 100 parts by weight, preferably 0.5 to 50 parts by weight, based on 100 parts by weight of the resin component. Thus, the volume resistance value of the elastic material layer can be reduced to 10 ⁶ -10 ¹³ Ω · cm, preferably 10 ⁷ -10 ¹² It can be adjusted to Ω · cm.
[0022]
In the present invention, other functional components can be added in addition to the above-mentioned components within a range not impairing the effects of the present invention. For example, various fillers, coupling agents, antioxidants, lubricants, surfaces Treatment agents, pigments, ultraviolet absorbers, antistatic agents, dispersants, neutralizing agents, foaming agents, crosslinking agents, compatibilizers, and the like can be appropriately blended.
The thickness of the conductive endless belt of the present invention is appropriately selected depending on the form of the transfer / conveying belt or the intermediate transfer member, but is preferably in the range of 50 to 200 μm.
[0023]
The conductive endless belt of the present invention has a surface on the side in contact with a driving member such as the driving roller 9 in FIG. 2 or the driving roller 30 in FIG. A fitting portion (not shown) formed on the driving member may be formed to be fitted, and the conductive endless belt of the present invention is provided with such a fitting portion, which is used as the driving member. By running with a fitting portion (not shown) provided, the displacement of the conductive endless belt in the width direction can be prevented.
In this case, the fitting portion is not particularly limited, but, as shown in FIG. 1, it is formed as a ridge continuous along the circumferential direction (rotation direction) of the belt, and this is a driving member such as a driving roller. It is preferable to be fitted in a groove formed in the circumferential surface along the circumferential direction.
[0024]
In addition, although the example which provided one continuous protruding item | line as a fitting part was shown in Fig.1 (a), this fitting part has many convex parts along the circumferential direction (rotation direction) of a belt. They may be arranged in a row, or two or more fitting portions may be provided (FIG. 1 (b)), or may be provided at the center in the width direction of the belt. Further, a groove along the circumferential direction (rotating direction) of the belt is provided as a fitting portion instead of the convex strip shown in FIG. 1, and this is formed along the circumferential direction on the circumferential surface of the driving member such as the driving roller. You may make it make it fit with the protruding item | line which carried out.
Examples of the image forming apparatus of the present invention using the conductive endless belt of the present invention are those of the tandem type shown in FIG. 2, the intermediate transfer type shown in FIG. 3, or the tandem intermediate transfer type. However, it is not limited to these. In the case of the apparatus shown in FIG. 3, a voltage can be applied from a suitable power source 61 to the driving roller or driving gear for rotating the intermediate transfer member 20 of the present invention. The application conditions, such as the application of weighting the alternating current, can be selected as appropriate.
[0025]
The method for producing the conductive endless belt of the present invention is not particularly limited. For example, a resin component (mixture of thermoplastic resin and whisker) and a functional component such as a conductive material are kneaded by a biaxial kneader. And the obtained kneaded material can be manufactured by extruding using an annular die. Alternatively, a powder coating method such as electrostatic coating, a solution dip method, or a centrifugal casting method can be suitably employed.
[0026]
【Example】
Hereinafter, the present invention will be described based on examples.
Example 1
Polyamide 12 resin (Daicel-Degusa Co., Ltd., Daiamide L1940) 50% by weight, antistatic agent (Ciba Geigy Co., Ltd., Irgastat P-18) 20% by weight, calcium silicate hydrate whisker (Ube) Made by Materials Co., Ltd., Zonoheiji (average fiber length 1-5 μm, average fiber diameter 0.1-0.5 μm, aspect ratio 10-20), Ca ₆ ・ Si ₆ O ₁₇ ・ (OH) ₂ 30% by weight was melt-kneaded with a biaxial kneader, and the resulting kneaded product was extruded to obtain a conductive endless belt having an inner diameter of 245 mm, a thickness of 100 μm, and a width of 250 mm.
The surface smoothness Ra of the conductive endless belt was measured using a surface roughness / shape measuring instrument Surfcom 590A manufactured by Tokyo Seimitsu Co., Ltd. As this value is smaller, the surface is smoother. Further, the number of times the conductive endless belt was bent was measured using a toughness fatigue tester manufactured by Toyo Seiki Co., Ltd., and the tensile creep amount was measured for 1200 hours at a temperature of 25 ° C. in accordance with the JIS K7115 test method. I went there. As the tensile creep amount is smaller, the creep resistance is more excellent. Further, the volume resistivity is measured at a temperature of 20 ° C. and a relative humidity of 50% at a measurement voltage of 100 V. As a measuring device, a resistance chamber made by ADVANTEST is connected to a resistance chamber R8340A and a sample chamber R12704A is used. I went.
[0027]
Example 2
A conductive endless belt was prepared in the same manner as in Example 1 except that acrylonitrile-butadiene-styrene resin (manufactured by Daicel Polymer Co., Ltd., Sebian V510) was used instead of polyamide 12 resin. The characteristics were measured.
[0028]
Example 3
Instead of calcium silicate hydrate whisker, basic magnesium sulfate hydrate whisker (Ube Materials Co., Ltd., Mosheidi, MgSO _Four ・ 5Mg (OH) ₂ ・ 3H ₂ A conductive endless belt was produced in the same manner as in Example 1 except that O) was used, and its characteristics were measured in the same manner as in Example 1.
[0029]
Example 4
Instead of calcium silicate hydrate whisker, potassium titanate whisker (manufactured by Otsuka Chemical Co., Ltd., Tismo-D, K) ₂ O · 8TiO ₂ A conductive endless belt was produced in the same manner as in Example 1 except that the above was used, and the characteristics were measured in the same manner as in Example 1.
[0030]
Example 5
A conductive endless belt was prepared in the same manner as in Example 1 except that the blending ratio was set to 68% by weight of polyamide 12 resin, 27% by weight of antistatic agent, and 5% by weight of calcium silicate hydrate whisker. The characteristics were measured in the same manner as described above.
[0031]
Example 6
A conductive endless belt was produced in the same manner as in Example 1 except that the blending ratio was 36% by weight of polyamide 12 resin, 14% by weight of antistatic agent, and 50% by weight of calcium silicate hydrate whisker. The characteristics were measured in the same manner as described above.
[0032]
Comparative Example 1
A conductive endless belt was prepared in the same manner as in Example 1 except that magnesium oxide (manufactured by Kamishima Chemical Co., Ltd., Starmag L, MgO) was used instead of calcium silicate hydrate whisker. The characteristics were measured in the same manner.
[0033]
Also, the conductive endless belts of the above examples and comparative examples are mounted on the tandem image forming apparatus using the transfer conveyance belt shown in FIG. 2, and the transfer operation is repeated to conduct a durability test on 100,000 sheets of A4 paper. It was. At this time, the image formed at any time and the surface of the conductive endless belt were observed to confirm the presence or absence of cracks, and the image quality and the surface property of the belt were evaluated. The case where the image was good and the belt was not cracked was OK, and the case where the image was bad and / or the surface of the belt was cracked was judged as NG.
Table 1 shows the results of the surface smoothness Ra, the number of bending resistances, the tensile creep amount, the volume resistivity, and the image quality. In the table, the number of bending resistances is shown as an index with the example being 100 or more.
[0034]
[Table 1]

[0035]
From the results of the above measurements and tests, it was confirmed that the conductive endless belts of the examples had significant advantages in terms of surface smoothness, bending durability, creep resistance, and image quality.
[0036]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a conductive endless belt having high dimensional accuracy and excellent in strength, in particular, bending durability, creep resistance and surface smoothness. Further, according to the image forming apparatus of the present invention using the conductive endless belt of the present invention, a good image can be obtained without a defect even after long-term use, and the belt is not easily deteriorated.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view in the width direction of a conductive endless belt according to an embodiment of the present invention.
FIG. 2 is a schematic diagram illustrating an example of a tandem type image forming apparatus using a transfer conveyance belt as an example of the image forming apparatus of the present invention.
FIG. 3 is a schematic view showing an example of an intermediate transfer type image forming apparatus using an intermediate transfer member as another example of the image forming apparatus of the present invention.
[Explanation of symbols]
1 Photosensitive drum
2 Charging roll
3 Development roll
4 Development blade
5 Toner supply roll
6 Cleaning blade
7 Charging roll
8 Static elimination roll
9 Drive roller (drive member)
10 Transfer conveyor belt
11 photoconductor
12 Primary charger
13 Image exposure
14,35 Cleaning device
19 Paper cassette
20 Intermediate transfer member
25 Transfer roller
26 Recording media
29,61 power supply
30 Drive roller
41, 42, 43, 44 Developer

Claims (6)

The recording medium held by electrostatic attraction is circulated and driven by a driving member, transported to four types of image forming bodies, and tandem transfer and / or transporting conductivity for sequentially transferring each toner image to the recording medium. A whisker (a fibrous inorganic compound having an aspect ratio of 10 or more) containing 90% by weight or more of a thermoplastic resin and calcium silicate hydrate (Ca ₆ (Si ₆ 0 ₁₇ ) (OH) ₂ ) as main components in an endless belt And / or metal particles) as a base material. The toner image formed between the image forming body and the recording medium is circulated and driven by a driving member, and the toner image formed on the surface of the image forming body is once transferred and held on the surface of the image forming body and transferred to the recording medium. A whisker (aspect ratio ) containing 90% by weight or more of a thermoplastic resin and calcium silicate hydrate (Ca ₆ (Si ₆ 0 ₁₇ ) (OH) ₂ ) as main components A conductive endless belt characterized by comprising a mixture of 10 or more fibrous inorganic compounds and / or metal particles) as a base material.   The conductive endless belt according to claim 1 or 2, wherein the ratio of the whisker component in the mixture is 5 to 50% by weight. The conductive endless belt according to any one of claims 1 to 3, wherein the whisker has an average long-axis fiber length of 0.2 to 40 µm. The conductive endless belt according to any one of claims 1 to 4, wherein the thermoplastic resin contains polyamide 12. An image forming apparatus characterized by using the electroconductive endless belt according to any one of claims 1-5.

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