JP5256579B2 - Belt-like conductive member and image forming apparatus - Google Patents

Description

  The present invention relates to a belt-like conductive member used in an image forming apparatus such as a copying machine, a printer, and a facsimile, in particular, a belt-like conductive member containing an elastic material and an image forming apparatus using the same.

  In an image forming apparatus such as a copying machine, a printer, or a facsimile, an image is formed on an image carrier such as a photosensitive drum, and the image is indirectly transferred to a recording material via an intermediate transfer belt, Some have already been provided for direct transfer to a recording material on a transfer / conveying belt. A belt-like conductive member is used as the intermediate transfer belt or the transfer conveyance belt.

  The intermediate transfer belt and the transfer / conveying belt used in the above-described image forming apparatus eliminate image defects such as image unevenness and obtain a more beautiful image, so that discharge products, residual toner, and toner external additives do not adhere to the belt surface. In addition, it is necessary to have a surface property (cleaning property) on which foreign substances are difficult to adhere.

  In this regard, if a resin layer is provided on the surface of the belt-like conductive member, cleaning properties can be ensured. However, for example, when cleaning is performed by pressing a cleaning blade, the belt surface must be smoothed in order to obtain good cleaning characteristics. If the belt surface is not smooth, the surface unevenness is used as a starting point. Cracks occur early due to strong adhesion of cleaning residual toner and toner external additives, and uneven thickness of the resin layer on the belt surface. There was a problem that the additive entered and caused cleaning failure.

On the other hand, a belt-like conductive member using a flexible resin as a binder resin for the surface layer so as to prevent cracking on the belt surface has been proposed (see, for example, Patent Documents 1 and 2). More specifically, the binder resin contains a fluororesin to give the belt surface releasability. However, since the binder resin itself has adhesiveness, the surface unevenness must be smooth. From this point, residual toner and toner external additives adhere firmly, and satisfactory cleaning properties cannot be ensured. In addition, if the surface is not smooth, the thickness of the resin layer becomes non-uniform and cracks on the surface are likely to occur, so that satisfactory cleaning properties cannot be ensured.
JP 2004-157289 A JP 2000-310912 A

The object of the present invention is to solve the above-mentioned problems of the prior art.
That is, the present invention provides a belt-like conductive member that can eliminate the occurrence of cracks on the surface by controlling the glossiness of the belt surface, and that can ensure cleanability, and an image forming apparatus using the belt-like conductive member. For the purpose.

The above-mentioned subject is achieved by the following present invention. That is, the present invention
<1> A base material containing a rubber material and a surface layer formed on the base material and containing a urethane resin, and having a 75-degree specular gloss Gs (75 °) on the surface, the process direction and the thrust direction both Ri range der of 75-90, an average roughness Rz of the substrate surface, a 4.25μm below the range of 2.79Myuemu, the thickness of the surface layer is less 3.0μm or 7.0μm It is a belt-shaped conductive member that is in the range.

<2> The belt-like conductive member according to <1>, wherein the base material contains synthetic rubber as a rubber material.

<3> The belt-like conductive member according to <1> or <2>, wherein the base material contains carbon black and / or a metal oxide.

<4> An image forming apparatus including the belt-like conductive member according to any one of <1> to <3>.

<5> The image forming apparatus according to <4>, further including a cleaning blade for cleaning the surface of the belt-like conductive member.

  According to the present invention, there is provided a belt-like conductive member capable of eliminating the occurrence of cracks on the surface by controlling the specular gloss of the belt surface and ensuring cleanability, and an image forming apparatus using the same. can do.

Hereinafter, the present invention will be described in detail.
<Belt-like conductive member>
The belt-like conductive member of the present invention comprises a base material containing a rubber material, and a surface layer formed on the base material and containing a urethane resin, and has a surface 75 ° specular gloss Gs (75 °). Is in the range of 75 to 90 in both the process direction and the thrust direction. However, in the present invention, the average roughness Rz of the substrate surface is in the range of 2.79 μm to 4.25 μm, and the thickness of the surface layer is in the range of 3.0 μm to 7.0 μm. A conductive member is applied.

  As described above, in order to improve the surface cleaning property, it is an effective means to form a resin layer on the surface of a belt having a base material containing a rubber material. However, if the belt surface is not smooth, for example, when used as a transfer / conveying belt, toner or the like adheres and cracks occur early. On the other hand, when the resin layer is thickened to improve smoothness, cracks may occur on the surface when it is stretched by a roll before it is actually used in the image forming apparatus.

  On the other hand, a base material containing a rubber material is usually prepared by polishing a surface of a cylindrical product obtained by a curing reaction process such as vulcanization with a grindstone. In this case, it has been found that the belt surface becomes polished skin by rubbing with a rotating grindstone, and the unevenness of the polished skin also affects the unevenness state of the belt surface after the surface layer is provided.

  In order to obtain a desired belt-like conductive member capable of maintaining uniform transfer performance without generating cracks, the present inventors have conducted extensive research focusing on the smoothness of the belt surface, and in the process, smoothed the belt surface. It was found that the specular gloss was found as an index of the property, and if the specular gloss was increased to a certain value or higher, the crack resistance could be ensured.

  Further, in the belt-like conductive member made of a rubber material as a base material, the surface of the base material is polished as described above, and the roughness of the surface of the base material depends on the circumferential direction of the belt ( The process direction) and the direction perpendicular to it (thrust direction) differed, but it was also confirmed that this roughness anisotropy particularly affects the initial crack generation.

  From the above, the present inventors have made the process direction and the thrust direction 75 degree specular gloss Gs (75 °) of the surface of the belt-like conductive member having the surface layer above a certain value, specifically 75-90. By setting the range, the surface resin layer is not cracked when the belt-like conductive member is stretched, and cleaning defects and surface irregularities do not occur. The present invention has been completed.

The 75 ° specular glossiness Gs (75 °) in the present invention is determined as follows.
FIG. 2 is a schematic diagram for explaining a method for measuring a 75-degree specular gloss of a belt-like conductive member according to the present invention. The mirror surface glossiness of the belt surface is measured by placing a flat metal plate 53 (material: SUS304, surface roughness Ra: 0.1 μm to 0.2 μm) so as to support the inner surface of the belt 51 as shown in the figure. The specular gloss measuring device 52 (BYK-Gardner, micro-gloss) is placed on the surface of the opposing belt 51, and the sample surface is irradiated with light at an incident light angle of 75 degrees according to JIS Z8741 (1997). Then, the 75-degree specular gloss Gs (75 °) of the belt surface in the process direction and the thrust direction was obtained.

  Here, the “75-degree specular gloss in the process direction” is a gloss when measured with the direction of the incident light coincident with the circumferential direction of the belt, and the “75-degree specular gloss in the thrust direction”. "Is a 75 degree specular gloss when measured with the direction of the incident light perpendicular to the belt circumferential direction. In addition, the measurement was performed at five points in different directions, and the average value was defined as the 75-degree specular gloss Gs (75 °) in each direction.

  The 75-degree specular gloss Gs (75 °) is preferably in the range of 75 to 85, and more preferably in the range of 76 to 84. When the 75 ° specular gloss Gs (75 °) is less than 75 °, cracks occur during use in the image forming apparatus, and when it exceeds 90, the cleaning property is deteriorated.

  The 75-degree specular gloss Gs (75 °) in the process direction and the thrust direction may be the same or different as long as they are within the above-mentioned range, but the same as the belt durability and transfer. It is preferable at the point which becomes a uniform smooth surface suitable for improving performance. Here, the same means that the difference between the 75-degree specular gloss in the process direction and the 75-degree specular gloss in the thrust direction is within 5.

Hereinafter, the configuration of the belt-like conductive member of the present invention will be described.
FIG. 1 shows a cross section when an example of the belt-like conductive member of the present invention is held in a cylindrical shape. This belt-like conductive member is configured by forming a surface layer 110 made of a resin composition on the outer peripheral surface of a substrate 100. A rubber material is used for the base material 100 of the belt-like conductive member of the present invention .

(Base material)
The substrate 100 in the present invention contains a rubber material. Although it does not restrict | limit especially as a rubber material, Since sufficient intensity | strength can be ensured when synthetic rubber is used as a transfer conveyance belt etc., it is preferable.
Synthetic rubber may be either solid or liquid, acrylic rubber, isoprene rubber, butadiene rubber, ethylene-propylene copolymer rubber, acrylonitrile-butadiene rubber, styrene-butadiene rubber, epichlorohydrin copolymer rubber, urethane rubber, silicone rubber Butyl rubber, chloroprene rubber, norbornene, and the like. Although not particularly limited, ethylene-propylene copolymer rubber, acrylonitrile-butadiene rubber, styrene-butadiene rubber, epichlorohydrin copolymer rubber, and chloroprene rubber are preferable. These rubber materials can be used alone or in admixture of two or more.

  The durometer hardness of the rubber material is preferably in the range of A40 / S to A90 / S. If the durometer hardness of the rubber material is less than A40 / S, the dimensional change over time due to belt tension may increase, and the roughness may be set within a preferable range in the polishing of the substrate described later. There are cases where it is not possible. On the other hand, when the durometer hardness of the rubber material exceeds A90 / S, the belt becomes hard, and when using it in close contact with the surface of the image carrier as a transfer conveyance belt or when using paper with irregularities on the surface, to those The follow-up performance may deteriorate.

  The measurement of the durometer is based on JIS K6253 (1997). The standard test piece is measured with a type A durometer hardness test. I asked for it.

  The substrate 100 in the present invention preferably contains a conductive agent. Examples of the conductive agent include metals or alloys such as carbon black, graphite, aluminum, nickel, and copper alloys, tin oxide, zinc oxide, and kalim titanate. And metal oxides such as tin oxide-indium oxide or tin oxide-antimony oxide composite oxide. Examples of the ion conductive conductive agent include sulfonates and ammonia salts, and various surfactants such as cationic, anionic, and nonionic surfactants.

Among these, it is preferable to contain carbon black and / or metal oxide from the viewpoint of stability of electric resistance against environmental fluctuations when used as a belt. Moreover, it is preferable that the said electrically conductive agent is contained in 1-50 mass parts with respect to 100 mass parts of rubber materials. The volume resistivity of the substrate 100 is preferably in the range of 1 × 10 ⁴ to 1 × 10 ⁹ Ωcm.

  Furthermore, the base material 100 in the present invention is usually made of rubber, such as a softener, a plasticizer, a curing agent, a vulcanizing agent, a vulcanization accelerator, an anti-aging agent, and a filler such as silica and calcium carbonate. Materials that can be added may be added.

  In the base material 100, the rubber material and various compounding agents are kneaded and mixed using a kneader such as a banbury mixer, a kneader, or a two-roller, and then the resulting mixture is tube-shaped using an extruder. After preforming, a cylindrical mold is coated and cross-linked by a method such as steam vulcanization, press vulcanization, transfer vulcanization, hot air vulcanization, etc. to produce a cylindrical molded product. It can be obtained by polishing the front and back surfaces of the shaped molded product with an NC polishing machine or the like.

  In order to set the 75-degree specular gloss on the surface of the belt-like conductive member in the present invention within the above range, the ten-point average roughness Rz of the substrate surface before forming the surface layer 110 is 3.0 to 5.0 μm. What is necessary is just to control to the range and to control the thickness of the surface layer 110 mentioned later to the range of 3.0-7.0 micrometers. By reducing the surface Rz and increasing the thickness of the surface layer 110 to a certain level or more, the 75-degree specular gloss of the obtained belt-shaped conductive member can be increased.

  If the roughness of the substrate surface is described in detail, the point where the ten-point average roughness Rz is in the range of 3.0 to 5.0 μm is satisfied in both the process direction and the thrust direction of the substrate 100. It will be necessary. When the above range is not satisfied in one direction, the range of the 75-degree specular gloss of the surface after the surface layer 110 is provided cannot be satisfied.

  The ten-point average roughness Rz of the substrate surface is preferably in the range of 1.0 to 8.0 μm, and more preferably in the range of 3.0 to 5.0 μm. A smooth surface such that Rz is less than 3.0 μm may not be obtained by normal polishing. When Rz exceeds 5.0 μm, the 75-degree specular gloss Gs (75 °) may not be 75 or more.

In the present invention, the ten-point average surface roughness Rz is the surface roughness defined in JIS B0601 (2001).
Further, the ten-point average surface roughness Rz can be measured using a surface roughness measuring instrument or the like. In the present invention, however, a contact-type surface roughness measuring device (in the environment of 23 ° C. and 55 RH%) Surfcom 570A, manufactured by Tokyo Seimitsu Co., Ltd.) was used. When measuring the surface of the substrate, the measurement distance was 2.5 mm, and the tip of the contact needle was diamond (5 μmR, 90 ° cone), and the average value was measured three times at different locations. The ten-point average surface roughness Rz of the substrate surface was obtained.

  However, the above polishing always causes minute irregularities in the circumferential direction of the belt. Therefore, in the present invention, it is preferable to change the surface condition such as surface irregularities in the circumferential direction depending on conditions such as the type of grindstone in the polishing process, the work rotation speed, the grindstone rotation speed, and the feed speed. In order to obtain a desired belt-shaped conductive member in the polishing process, the grinding of the belt surface may be performed by reducing the grindstone particle size, increasing the grindstone rotation speed, slowing the workpiece rotation speed, and slowing the feed speed.

  More specifically, for example, when a traverse polishing machine is used, a grindstone having a particle size in the range of 60 to 180 is used, the rotational speed of the grindstone is in the range of 1000 to 5000 rpm, and the rotational speed of the workpiece is 50 to 1000 rpm. It is preferable to perform polishing within the range.

When polishing the substrate 100, the surface of the cylindrical molded product obtained by coating the rubber mold with the cylindrical mold and vulcanizing is first polished, and then the front and back of the molded product are reversed. It is preferable to make the surface of the substrate 100 by polishing.
By performing polishing in this way and forming the surface of the base material 100, the back surface after inversion is a smooth surface, so that the surface side polishing can be performed without being affected by the unevenness of the back surface, Not only can the surface of the substrate 100 be easily accommodated in the desired surface roughness range, but also the roughness uniformity can be improved.

(Surface layer)
The surface layer 110 in the present invention is formed of a resin . Examples of the resin to be used include urethane resin, polyester, phenol, acrylic, polyurethane, epoxy resin, cellulose, copolymer nylon, and the like, but at least a urethane resin is used in the present invention . Among these, the copolymer nylon includes one or more of 610 nylon, 11 nylon, and 12 nylon as polymerized units, and other polymer units contained in the copolymer include: Examples include 6 nylon and 66 nylon.

  Here, it is preferable that the ratio of the polymer units made of 610 nylon, 11 nylon, and 12 nylon to be contained in the copolymer is 10% or more in terms of mass ratio. When the above polymerized unit is 10% or more, it is excellent in liquid preparation and film-forming properties at the time of coating the surface layer, and particularly less wear of the resin layer and adhesion of foreign matter to the resin layer during repeated use, and durability of the belt In addition, the hygroscopicity is low, and the change in properties due to the environment is reduced.

The surface layer 110 may contain a particulate conductive agent. The particulate conductive agent is preferably a conductive material having a particle size of 3 μm or less and a volume resistivity of 10 ⁹ Ωcm or less. For example, fine particles made of metal oxides such as tin oxide, titanium oxide, zinc oxide, CeO ₂ , ZrO ₂ , In ₂ O ₃ or alloys thereof, or these metals on the surface of fine particles such as BaSO ₄ or TiO _2. An oxide-coated one or carbon black can be used.

The addition amount of the particulate conductive agent is preferably set in a range in which the volume resistivity of the surface layer 110 can be 10 ⁹ Ωcm or more in order to obtain a desired belt resistance value, and the addition amount is the conductivity to be added. Although it cannot be defined because it varies depending on the particle, when the above-mentioned various resins are used, the addition amount is preferably in the range of 1 to 150 parts by mass with respect to 100 parts by mass of the resin solid content.

  Further, the surface layer 110 in the present invention may be added with a fluorine-based or silicone-based resin or fine particles, and in that case, the surface becomes hydrophobic to prevent foreign matter from adhering to the belt surface. Works. A coupling agent can also be added to improve the adhesion between the surface layer 110 and the lower layer.

As described above, in order to set the 75-degree specular gloss Gs (75 °) of the surface of the belt-like conductive member in the range of 75 to 90, in addition to controlling the surface roughness of the substrate 11, the surface layer The thickness of 110 is preferably in the range of 3.0 to 7.0 μm, and more preferably in the range of 4.0 to 6.0 μm.
If the thickness is less than 3.0 μm, the unevenness on the surface of the substrate cannot be sufficiently covered, and a desired specular gloss may not be obtained. If the thickness exceeds 7.0 μm, the surface layer becomes too thick, and cracks may occur in the initial state where the belt is stretched as a belt.

  The surface layer 110 is formed, for example, by applying a coating solution for forming a surface layer to the substrate 100 by dip coating, spray coating, flow coating, electrostatic coating, blade coating, roller coating, or the like. As the coating method, dip coating, spray coating, and flow coating are preferable.

  The belt-like conductive member of the present invention produced as described above may have a thickness in the range of 0.4 to 0.8 mm, a peripheral length in the range of 100 to 600 mm, and a width in the range of 200 to 400 mm. preferable.

The volume resistivity of the belt-like conductive member of the present invention is preferably in the range of 1.0 × 10 ^{4 to} 1.0 × 10 ¹² Ωcm. Further, as the intermediate transfer belt, 1.0 × 10 The range of ^{7 to} 1.0 × 10 ¹¹ Ωcm is preferable, and the range of 5.0 × 10 ^{4 to} 1.0 × 10 ¹⁰ Ωcm is preferable as the transfer conveyance belt.
In addition, the volume resistivity is an electric resistance value at an applied voltage of 500 V and a value of 10 seconds in an environment of 23 ° C. and 55% RH using an Mitsubishi high HR probe by an ultra-high resistance / microammeter manufactured by Advantest. It was calculated | required by measuring. The measurement of the volume resistivity of the substrate is the same.

<Image forming apparatus>
The image forming apparatus of the present invention is an image forming apparatus provided with the above-described belt-like conductive member of the present invention. In the image forming apparatus of the present invention, the belt-like conductive member of the present invention is preferably used as a transfer conveyance belt or an intermediate transfer belt, and more preferably used as a transfer conveyance belt.
Hereinafter, one embodiment of an image forming apparatus including the belt-like conductive member of the present invention will be described with reference to FIG.

FIG. 3 is a schematic configuration diagram for explaining one embodiment of the image forming apparatus of the present invention.
In FIG. 3, reference numeral 10 denotes a photosensitive drum (image carrier), which rotates in the direction of arrow A. Then, around the photosensitive drum 10, a charger 11 for uniformly charging the drum surface (photosensitive layer), and an optical image corresponding to predetermined image information is exposed on the charged photosensitive drum 10. An image exposure device 12 that forms an electrostatic latent image, a developing device (developing means) 13 that develops the electrostatic latent image by supplying a developer to the surface of the photosensitive drum 10 and forms a toner image, and records a toner image T A belt-type transfer device (transfer means) 18 for transferring to the paper P, a cleaning device 14 for removing toner remaining on the photosensitive drum 10 after transfer, and the like are provided.

  Reference numeral 15 denotes a paper feed tray for storing recording paper P in a stacked manner, 15a denotes a feed roll for feeding the recording paper P from the paper feed tray 15 one by one, and 16 denotes the recording paper P sent from the paper feed tray 15. A registration roll 17 is sent out between the photosensitive drum 10 and the transfer device 18 at a predetermined timing, and 17 is a roll type fixing device (fixing means) for fixing the transferred toner image onto the recording paper P.

  In the present embodiment, the transfer device 18 rotates in the direction of arrow B in synchronization with the photosensitive drum 10 in a state where the transfer conveyance belt 20 is stretched and the transfer conveyance belt 20 is stretched. The supporting rolls 21 and 22 that are supported so as to travel, the bias power supply 23 that supplies the transfer conveying belt 20 with a transfer bias having a polarity opposite to the toner charging polarity of the transfer toner image, and the transfer bias output from the bias power supply 23 The power feeding roll 24 applied to the transfer / conveying belt 20 and the cleaning blade 25 that removes toner and the like adhering to the transfer / conveying belt 20 constitute the main parts.

  The transfer conveyance belt 20 is disposed so as to contact the photosensitive drum 10 and form a transfer nip portion N while being stretched by two support rolls 21 and 22. At least the support roll 21 on the upstream side of the transfer nip portion N is disposed in a grounded state, and one of the two support rolls is a drive roll for the transfer conveyance belt 20. (In this example, the support roll 21 is a drive roll for the transfer conveyance belt 20).

  Further, the power supply roll 24 is disposed between the two support rolls 20 and 21 that support the surface in contact with the photosensitive drum 10 so as to contact the back surface side of the transfer conveyance belt 20. The bias power source 23 outputs a transfer bias having a bias waveform composed of rectangular pulses.

  Furthermore, a motor 30 that is a driving source for driving the photosensitive drum 10 and a motor 31 that is a support roll for the transfer conveyance belt 20 and a drive roll that drives a drive roll that rotates the transfer conveyance belt 20 are provided. The motor 30 and the motor 31 have a structure capable of outputting the rotation state of an encoder or the like inside, and the output is sent to the drive controller 70 as needed. The drive controller 70 includes a comparison circuit that monitors the rotation state sent from the motor 30 and the motor 31 and compares the rotation speeds of the two motors. The rotation is controlled.

  On the other hand, the bias power source 23 that applies a bias to the power supply roll 24 is controlled by a controller 19 that is a control unit of the bias power source. An appropriate bias value is applied to the power supply roller 24 at an appropriate timing under the control of the controller 19. The voltage value applied to the power supply roll 24 is monitored by the controller 19, and the information (transfer electric field) is sent to the drive controller 70 described above.

Next, an image forming process in one embodiment of the image forming apparatus of the present invention will be described.
First, the photosensitive layer of the rotating photosensitive drum 10 is uniformly charged by a charger 11, and an optical image or image-modulated laser beam in which reflected light from an original is converged by an image exposure device 12 on the charging surface. The optical image is irradiated to form an electrostatic latent image. Subsequently, toner is supplied from the developing device 13 and adheres only to the electrostatic latent image on the photosensitive drum 10 to form a toner image T. In this example, the photosensitive drum 10 is uniformly charged to a negative polarity to form an electrostatic latent image for reversal development, and then developed with a negatively charged toner. Therefore, the negatively charged toner image T Is to be formed.

  Subsequently, in accordance with the formation timing of the toner image T, the recording paper P of a predetermined size and type is sent out from the paper feed tray 15 one by one by the feed roll 15a, and the timing is adjusted by the registration roll 16. It is sent out toward the transfer nip N. A predetermined voltage (V 0) or a predetermined current (I 0) is applied from the bias power source 23 based on an instruction from the controller 19 immediately before the leading edge of the recording paper P passes through the transfer nip N.

  As a result, the recording paper P is fed to the transfer nip N facing the photosensitive drum 10 and then electrostatically attracted to the surface of the transfer conveyance belt 20 so that the recording paper P is exposed to the photosensitive nip 10 at an appropriate speed. The toner image T is electrostatically transferred from the drum 10. The recording paper P onto which the toner image T has been transferred is separated from the belt at the portion of the transfer / conveying belt 20 supported by the support roll 22 and then peeled off, and then sent to the fixing device 17 to fix the toner image T. Is finally discharged to the outside of the apparatus. Thus, an image is formed.

  On the other hand, a cleaning blade 25 is always pressed against the transfer conveyance belt 20 that conveys the recording paper P, and the surface of the transfer conveyance belt after the recording paper P is peeled is cleaned. Accordingly, there is no transfer residual toner or the like in the portion where the recording paper P is transported for the next transfer process, and problems such as back surface contamination do not occur.

In the image forming apparatus of the present invention, it is preferable that the transfer conveyance belt 20 has a circumferential length of 1 to 5%, and the linear velocity for conveying the recording paper P is in the range of 100 to 500 mm / second. It is preferable.
Moreover, it is preferable to use urethane rubber as a material of the cleaning blade 25, and it is preferable that the pressure of the pressure contact is in a range of 1 to 100 Nm.

The image forming apparatus of the present invention uses the belt-like conductive member of the present invention as the transfer conveyance belt 20, so that the surface is smooth and cracks do not occur during initial stretching or use, and continuous image formation In this case, the toner and paper can be easily peeled off, stable paper adsorbability and paper transportability can be obtained even when used for a long time, and the transfer characteristics can be stabilized.
Further, the belt-like conductive member of the present invention can obtain the same effects as when used as an intermediate transfer belt when used as an intermediate transfer belt.

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.
<Example 1>
(Preparation of belt-shaped conductive member)
100 parts by mass of epichlorohydrin copolymer (manufactured by Nippon Zeon Co., Ltd., Zeklon 3106), 30 parts by mass of Asahi Thermal (manufactured by Asahi Carbon Co., Ltd.), 10 parts by mass of Ketjen Black EC, magnesium oxide (manufactured by Kyowa Chemical Industry Co., Ltd., Kyowa Mag 150) 4 Part by mass, 0.5 part by mass of sulfur (made by Tsurumi Chemical Co., Ltd., 200 mesh), 5.0 parts by mass of zinc oxide (Nippon Chemical Industry Co., Ltd. No. 1) and 2.0 parts by mass of vulcanization accelerator (Ouchi Shinsei Chemical) Manufactured by Kogyo Co., Ltd., Noxeller TS: 1.0 part by mass, Noxeller DT: 1.0 part by mass) were mixed and kneaded with an open roll to obtain a mixture.

  This mixture was coated on the outer peripheral surface of a metal pipe having a diameter of 95 mm in a cylindrical shape having a thickness of 1.0 mm, placed in a vulcanizing can and vulcanized at 170 ° C. for 30 minutes, and a cylindrical molded product (durometer hardness: A58 / S) was obtained. The surface of this molded product was polished by a traverse polishing machine, then extracted from a metallic pipe, the belt was turned upside down, and the back surface of the belt was polished. Next, after reversing the front and back of the belt and polishing the belt surface so that the ten-point average roughness Rz is about 5 μm, the front and back of the belt are reversed again and finally the grindstone particle size is 80, and the rotation of the grindstone The back surface of the belt was polished under the conditions that the number was 2000 rpm and the work rotation number was 360 rpm, to obtain a base material having a thickness of 0.47 mm. The ten-point average roughness Rz of the substrate surface (the belt back surface) was 4.02 μm in the process direction and 3.89 μm in the thrust direction.

Subsequently, the surface of the base material is coated by spray coating using a urethane-based paint for forming a surface layer (JLY-601ESD, manufactured by Nippon Atchison Co., Ltd.), and baked at 140 ° C. for 30 minutes. Formed. In this case, the thickness of the surface layer was 5.0 μm. Thus, the intended belt-like conductive member (1) was obtained.
The obtained belt-like conductive member (1) had a 10-point average surface roughness Rz of 1.63 μm, a 75 ° specular gloss of 77.2 in the process direction, and 76.0 in the thrust direction. The volume resistivity was 5.4 × 10 ⁵ Ωcm.

(Evaluation)
The belt-like conductive member thus produced is mounted as a transfer conveyance belt of DocuCentre a1100 (Fuji Xerox Co., Ltd., equipped with a transfer conveyance belt having a cleaning blade), and is an environment having a temperature of 22 ° C. and a humidity of 55% RH. Below, the following evaluation was performed about the initial stage and after printing 60000 sheets.

-Image quality-
A 30% halftone image was printed and evaluated according to the following criteria.
○: No defect occurred.
Δ: Defect occurred but still within tolerance.
X: Defect occurred but out of tolerance.

-Crack resistance-
The belt surface was visually observed and evaluated according to the following criteria.
○: No crack occurred.
Δ: Cracks are generated but within the allowable range.
×: Cracks are generated but outside the allowable range.

Further, the paper transportability was evaluated according to the following criteria.
○: No trouble occurred.
×: Trouble occurred.
The above results are summarized in Table 1.

<Example 2>
(Preparation of belt-like conductive member)
70 parts by mass of chloroprene (manufactured by Denki Kagaku Kogyo Co., Ltd., ES-40) and 30 parts by mass of an ethylene propylene copolymer (manufactured by JSR, EP-33), 40 parts by mass of Asahi Thermal (manufactured by Asahi Carbon Co., Ltd.), Ketjen Black EC 13 parts by mass, magnesium oxide (Kyowa Chemical Industry Co., Ltd., Kyowa Mag 150) 4 parts by mass, sulfur (Tsurumi Chemical Co., Ltd., 200 mesh) 0.5 parts by mass, zinc oxide (Nippon Chemical Industry No. 1) 0 parts by mass and 2.0 parts by mass of a vulcanization accelerator (Nouchira TS: 1.0 part by mass, Noxeller DT: 1.0 part by mass) are mixed and kneaded with an open roll. A mixture was obtained.

This mixture was coated on the outer peripheral surface of a metal pipe having a diameter of 95 mm in a cylindrical shape having a thickness of 1.0 mm, placed in a vulcanizing can and vulcanized at 170 ° C. for 30 minutes, and a cylindrical molded product (durometer hardness: A56 / S) was obtained.
Using this molded product, polishing was performed in the same manner as in Example 1 to prepare a substrate, and a surface layer was formed in the same manner to obtain a belt-like conductive member (2). These characteristics are summarized in Table 1.

(Evaluation)
Evaluation was performed in the same manner as in Example 1 using the belt-shaped conductive member (2). The results are summarized in Table 1.

<Example 3>
(Preparation of belt-like conductive member)
70 parts by mass of chloroprene (manufactured by Denki Kagaku Kogyo Co., Ltd., ES-40) and 30 parts by mass of an epichlorohydrin copolymer (manufactured by Nippon Zeon Co., Ltd., Zeklon 3106), 30 parts by mass of Asahi Thermal (manufactured by Asahi Carbon Co., Ltd.), Ketjen Black EC 11 parts by mass, magnesium oxide (Kyowa Chemical Industry Co., Ltd., Kyowa Mag 150) 4 parts by mass, sulfur (Tsurumi Chemical Industry Co., Ltd. 200 mesh) 0.5 parts by mass, zinc oxide (Nippon Chemical Industry No. 1) 5.0 parts by mass Part, vulcanization accelerator 2.0 parts by mass (Ouchi Shinsei Chemical Co., Ltd. Noxeller TS: 1.0 part by mass, Noxeller DT: 1.0 part by mass) are mixed and kneaded with an open roll. Obtained.

This mixture was coated on the outer peripheral surface of a metal pipe having a diameter of 95 mm in a cylindrical shape having a thickness of 1.0 mm, placed in a vulcanizing can and vulcanized at 170 ° C. for 30 minutes, and a cylindrical molded product (durometer hardness: A58 / S) was obtained.
Using this molded product, polishing was performed in the same manner as in Example 1 to prepare a base material, and a surface layer was formed in the same manner to obtain a belt-like conductive member (3). These characteristics are summarized in Table 1.

(Evaluation)
Evaluation was performed in the same manner as in Example 1 using the belt-shaped conductive member (3). The results are summarized in Table 1.

<Example 4>
(Preparation of belt-like conductive member)
30 parts by mass of chloroprene (manufactured by Denki Kagaku Kogyo Co., Ltd., ES-40), 40 parts by mass of an ethylene propylene copolymer rubber (manufactured by JSR, EP-33) and an epichlorohydrin copolymer (manufactured by Nippon Zeon Co., Ltd., Zeklon 3106) Asahi Thermal (Asahi Carbon Co., Ltd.) 40 parts by mass, Ketjen Black EC 11 parts by mass, magnesium oxide (Kyowa Chemical Industry Co., Ltd., Kyowa Mag 150) 4 parts by mass, sulfur (Tsurumi Chemical Co., Ltd. 200 mesh) 5 parts by mass, 5.0 parts by mass of zinc oxide (Nippon Chemical Industry Co., Ltd. No. 1) and 2.0 parts by mass of vulcanization accelerator (Ouchi Shinsei Chemical Co., Ltd. Noxeller TS: 1.0 part by mass, Noxeller DT: 1 0.0 parts by mass) were mixed and kneaded with an open roll to obtain a mixture.

This mixture was coated on the outer peripheral surface of a metal pipe having a diameter of 95 mm in a cylindrical shape having a thickness of 1.0 mm, placed in a vulcanizing can and vulcanized at 170 ° C. for 30 minutes, and a cylindrical molded product (durometer hardness: A58 / S) was obtained.
Using this molded product, polishing was performed in the same manner as in Example 1 to prepare a substrate, and a surface layer was formed in the same manner to obtain a belt-like conductive member (4). These characteristics are summarized in Table 1.

(Evaluation)
Evaluation was performed in the same manner as in Example 1 using the belt-shaped conductive member (4). The results are summarized in Table 1.

<Comparative Example 1>
(Preparation of belt-like conductive member)
100 parts by mass of an epichlorohydrin copolymer (manufactured by Nippon Zeon Co., Ltd., Zeklon 3106), 30 parts by mass of Asahi Thermal (manufactured by Asahi Carbon Co., Ltd.), 8 parts by mass of Ketjen Black EC, magnesium oxide (manufactured by Kyowa Chemical Industry Co., Ltd., Kyowa Mag 150) 4 parts by mass, 0.5 parts by mass of sulfur (200 mesh manufactured by Tsurumi Chemical Co., Ltd.), 5.0 parts by mass of zinc oxide (Nippon Chemical Industry Co., Ltd. No. 1) and 2.0 parts by mass of vulcanization accelerator (Ouchi Shinsei Chemical) Kogyo Noxeller TS: 1.0 part by mass, Noxeller DT: 1.0 part by mass) were mixed and kneaded with an open roll to obtain a mixture.

This mixture was coated on the outer peripheral surface of a metal pipe having a diameter of 95 mm in a cylindrical shape having a thickness of 1.0 mm, placed in a vulcanizing can and vulcanized at 170 ° C. for 30 minutes, and a cylindrical molded product (durometer hardness: A61S) was obtained.
Using this molded product, polishing was carried out in the same manner as in Example 1 to prepare a substrate, and a surface layer was formed in the same manner to obtain a belt-like conductive member (5). These characteristics are summarized in Table 1.

(Evaluation)
Evaluation was performed in the same manner as in Example 1 using the belt-shaped conductive member (5). The results are summarized in Table 1.

<Comparative example 2>
(Preparation of belt-like conductive member)
70 parts by mass of epichlorohydrin copolymer (manufactured by Nippon Zeon Co., Ltd., Zeklon 3106), 30 parts by mass of ethylene propylene copolymer (manufactured by JSR, EP-33), 30 parts by mass of Asahi Thermal (manufactured by Asahi Carbon Co., Ltd.), Ketjen 11 parts by weight of black EC, 4 parts by weight of magnesium oxide (manufactured by Kyowa Chemical Industry Co., Ltd., Kyowa Mag 150), 0.5 parts by weight of sulfur (manufactured by Tsurumi Chemical Industry Co., Ltd., 200 mesh), 5 parts by weight of zinc oxide (Nippon Chemical Industry Co., Ltd. No. 1) 5 0.0 parts by mass and 2.0 parts by mass of a vulcanization accelerator (Nouchira TS: 1.0 part by mass, Noxeller DT: 1.0 parts by mass, manufactured by Ouchi Shinsei Chemical Co., Ltd.) are added and kneaded with an open roll. A mixture was obtained.

This mixture was coated on the outer peripheral surface of a metal pipe having a diameter of 95 mm in a cylindrical shape having a thickness of 1.0 mm, placed in a vulcanizing can and vulcanized at 170 ° C. for 30 minutes, and a cylindrical molded product (durometer hardness: A59 / S) was obtained.
Using this molded product, polishing was performed in the same manner as in Example 1 to prepare a substrate, and a surface layer was formed in the same manner to obtain a belt-like conductive member (6). These characteristics are summarized in Table 1.

(Evaluation)
Evaluation was performed in the same manner as in Example 1 using the belt-shaped conductive member (6). The results are summarized in Table 1.

<Comparative Example 3>
70 parts by mass of chloroprene (manufactured by Denki Kagaku Kogyo Co., Ltd., ES-40) and 30 parts by mass of epichlorohydrin copolymer (manufactured by Nippon Zeon Co., Ltd., Zeklon 3106), 40 parts by mass of Asahi Thermal (manufactured by Asahi Carbon Co., Ltd.), Ketjen Black EC 10 parts by mass Magnesium oxide (Kyowa Chemical Industry Co., Ltd., Kyowa Mag 150) 4 parts by mass, sulfur (Tsurumi Chemical Industry Co., Ltd. 200 mesh) 0.5 parts by mass, zinc oxide (Nippon Chemical Industry No. 1) 5.0 parts by mass And 2.0 parts by mass of a vulcanization accelerator (Ouchi Shinsei Chemical Co., Ltd. Noxeller TS: 1.0 part by mass, Noxeller DT: 1.0 part by mass) were added and kneaded with an open roll to obtain a mixture. .

This mixture was coated on the outer peripheral surface of a metal pipe having a diameter of 95 mm in a cylindrical shape having a thickness of 1.0 mm, placed in a vulcanizing can and vulcanized at 170 ° C. for 30 minutes, and a cylindrical molded product (durometer hardness: A58 / S) was obtained.
Using this molded product, polishing was performed in the same manner as in Example 1 to prepare a substrate, and a surface layer was formed in the same manner to obtain a belt-like conductive member (7). These characteristics are summarized in Table 1.

(Evaluation)
Evaluation was performed in the same manner as in Example 1 using the belt-shaped conductive member (7). The results are summarized in Table 1.

<Comparative example 4>
100 parts by mass of chloroprene (manufactured by Denki Kagaku Kogyo Co., Ltd., ES-40), 40 parts by mass of Asahi Thermal (manufactured by Asahi Carbon Co., Ltd.), 11 parts by mass of Ketjen Black EC, magnesium oxide (Kyowa Chemical Industry Co., Ltd., Kyowa Mag 150) 4 Part by mass, 0.5 part by mass of sulfur (made by Tsurumi Chemical Co., Ltd., 200 mesh), 5.0 parts by mass of zinc oxide (Nippon Chemical Industry Co., Ltd. No. 1) and 2.0 parts by mass of vulcanization accelerator (Ouchi Shinsei Chemical) Industrial Co., Ltd., Noxeller TS: 1.0 part by mass, Noxeller DT: 1.0 part by mass) were added and kneaded with an open roll to obtain a mixture.

This mixture was coated on the outer peripheral surface of a metal pipe having a diameter of 95 mm in a cylindrical shape having a thickness of 1.0 mm, placed in a vulcanizing can and vulcanized at 170 ° C. for 30 minutes, and a cylindrical molded product (durometer hardness: A58 / S) was obtained.
Using this molded product, polishing was performed in the same manner as in Example 1 to prepare a substrate, and a surface layer was formed in the same manner to obtain a belt-like conductive member (8). These characteristics are summarized in Table 1.

(Evaluation)
Evaluation was performed in the same manner as in Example 1 using the belt-shaped conductive member (8). The results are summarized in Table 1.

  As shown in Table 1, in the belt-like conductive member of the example in which the roughness of the substrate surface was controlled and the 75-degree specular gloss of the belt surface was within the range specified in the present invention, the initial value after printing 60000 sheets In both cases, good image quality was obtained, and no problematic cracks were generated in the belt. On the other hand, the belt of the comparative example having a low 75 degree specular gloss has a problem in either image quality or crack resistance.

It is sectional drawing which shows an example of a structure of the belt-shaped electroconductive member of this invention. It is a schematic diagram for demonstrating the method to measure the specular glossiness of the belt surface. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus of the present invention.

Explanation of symbols

10 Photosensitive drum,
11 Charger,
12 image exposure apparatus,
13 Development device,
14 Cleaning device,
15 Paper tray,
15a feed roll,
16 resist rolls,
17 roll type fixing device,
18 Transfer device,
19 controller,
20 transfer conveyor belt,
21, 22 support rolls,
23 Bias power supply,
24 Power feed roll,
25 Cleaning blade,
30, 31 Motor 51 Belt 52 Specular Gloss Measuring Device 53 Metal Plate 70 Drive Controller 100 Base Material 110 Surface Layer T Toner Image,
P recording paper,
N Transfer nip

Claims (5)

It consists of a base material containing a rubber material, and a surface layer formed on the base material and containing a urethane resin, and the surface has a 75-degree specular gloss Gs (75 °) of 75 to 75 in both the process direction and the thrust direction. 90 range der of is, the average roughness Rz of the substrate surface, a 4.25μm below the range of 2.79Myuemu, the thickness of the surface layer, is 7.0μm or less the range of 3.0μm belt-shaped conductive member, characterized in that.   The belt-like conductive member according to claim 1, wherein the base material contains synthetic rubber as a rubber material.   The belt-like conductive member according to claim 1 or 2, wherein the base material contains carbon black and / or a metal oxide.   An image forming apparatus comprising the belt-like conductive member according to claim 1.   The image forming apparatus according to claim 4, further comprising a cleaning blade for cleaning a surface of the belt-like conductive member.

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