JP5529490B2 - Endless belt - Google Patents

Description

  The present invention relates to an endless belt as a toner image carrier that carries and conveys a toner image, and in particular, even if at least one end surface in the width direction is used as a guide surface to prevent meandering, durability at the end portion is reduced. For things that don't happen.

  In general, endless belts are frequently used for applications such as toner image transfer and paper transfer conveyance in electrophotographic apparatuses employing electrophotographic technology such as full color LBP and full color PPC. As such an endless belt, for example, a resin material such as PVDF (polyvinylidene fluoride), a resin material such as a polycarbonate resin, a polyimide resin, and the like, a dipping method, an extrusion method, What was formed in the cylindrical film by methods, such as a centrifugal molding method, is used.

  Such an endless belt travels while being supported and driven by a stretching roller, and the positional accuracy in the width direction at that time is extremely important for high-precision image formation. 1 (a) is a perspective view of an endless belt, and FIG. 1 (b) is a cross-sectional view of one end of the endless belt. An endless belt 90 configured to engage 92 with a guide groove 93 is known (see, for example, Patent Document 1).

  However, this means requires the cost of the rib guide 92 itself and the cost for adhering the rib guide 92 to the belt body 91, and also requires the provision of the guide groove 93, so that cost reduction has been demanded. In order to cope with such a problem, FIG. 2 (a) is a perspective view of an endless belt and FIG. 2 (b) is a cross-sectional view of one end thereof as meandering prevention means that does not require the rib guide 92. In addition, the end face belt 91 in which the width direction end face 91a of the belt main body 91 is directly pressed against the guide member 95, and a reinforcing tape 94 is attached to prevent the end of the belt pressed against the guide member 95 which is a problem in this case. 90A has been proposed (see, for example, Patent Document 1).

JP 2004-46199 A JP-A-11-219046

  However, since the reinforcing tape 94 is not endless, there is a problem that a joint 96 that connects the starting end and the terminal end of the reinforcing tape 94 is inevitably generated, and the reinforcing tape 94 is peeled off from the connecting tape 96 and durability is lowered. It was. In addition, the reinforcing tape 94 has a problem that it takes time to apply the reinforcing tape 94 and the cost reduction is not sufficient.

  The present invention has been made in view of such problems, and an object of the present invention is to provide an endless belt that can ensure durability and can sufficiently reduce the cost.

<1>, in the endless belt as a toner image bearing member which holds and conveys a toner image, over the entire periphery in the width direction at least one end portion of one side or ultraviolet-curable resins by Li Cheng coating on both surfaces An endless belt characterized by being formed.

  <2> is an endless belt according to <1>, wherein the coating film has a thickness of 10 to 200 μm.

  <3> is an endless belt according to <1> or <2>, wherein the coating film has a width of 1.0 to 10.0 mm.

  <4> is an endless belt characterized in that in any one of <1> to <3>, the coating film is formed via a primer layer.

  According to <1>, since the coating film is formed over the entire circumference on at least one side or both sides of one end in the width direction, the circumferential joints and cuts are eliminated unlike the case where the reinforcing tape is attached to the belt body. Therefore, it is possible to ensure sufficient durability because it does not cause a starting point to peel off the coating film, and the coating film is made of at least one of an ultraviolet curable resin, a thermoplastic elastomer and a thermosetting resin. Therefore, the coating film can be easily cured and a low-cost end reinforcing means can be configured.

  <2> is a film having a thickness of 10 to 200 μm, and if the thickness is less than 10 μm, the belt end surface hits the guide member due to repeated running of the belt, and deformation occurs. There is a problem that the shape of the end cannot be maintained. On the other hand, if this exceeds 200 μm, the belt end becomes too rigid and passes through the stretching roller. The belt is bent and cannot be flexibly bent, and the belt end portion is cracked and the reinforcing effect is lost.

  <3> is for the width of the coating film to be 0.1 to 10.0 mm. If the thickness is less than 0.1 mm, the belt end surface hits the guide member due to repeated running of the belt and deformation occurs. The problem that the shape of the end cannot be maintained occurs, and if this exceeds 10.0 mm, the belt end becomes too rigid and the belt passes through the stretching roller. The end portion is bent and cannot be flexibly bent, and the end portion of the belt cracks and the reinforcing effect is lost.

  According to <4>, since the said coating film was formed through the primer layer, a coating film can be adhere | attached more reliably and it can be made to contribute further to the strength improvement of an edge part with peeling prevention.

It is the perspective view and sectional drawing which show the conventional endless belt. It is the perspective view and sectional drawing which show the other conventional endless belt. It is the perspective view and sectional drawing which show the endless belt of embodiment which concerns on this invention. It is the perspective view and sectional drawing which show the endless belt of other embodiment which concerns on this invention. It is a schematic diagram which shows the cutting process of an endless belt. It is a schematic diagram which shows the attachment method of the belt in an Example.

  An endless belt according to an embodiment of the present invention will be described with reference to the drawings. FIG. 3A is a perspective view showing the endless belt of the embodiment, FIG. 3B is a cross-sectional view showing an end portion on one side, and the endless belt 10 is made of a resin having a constant thickness. Belt body 1 and coating film 2 made of an ultraviolet curable resin formed on one or both surfaces of at least one end thereof. This endless belt 10 brings the entire belt body 1 toward the guide member 4 and directly presses the end surface 1a against the guide member 4, thereby accurately positioning the endless belt 10 in the belt width direction at least at the position of the guide member 4. In order to prevent meandering of the endless belt, the end face 1a of the belt body 1 directly hits the guide member 4 to reinforce cracks and the like generated at the end by the coating film 2 formed there. It can suppress, and the fall of the lifetime of the edge part resulting from it can be prevented.

  Ultraviolet curable resin materials include epoxy acrylic resins and acrylic urethane resins, thermoplastic elastomers include polyurethane, polyester, SEBS, and SBS. Thermosetting resins include acrylic resins and epoxy resins. And urethane resin can be illustrated respectively. The thickness t of the coating film is preferably 10 to 200 μm, and the width a of the coating film is preferably 0.1 to 10.0 mm. Further, the coating film may not be flush with the end surface 1a of the belt body 1, and the distance b from the outer edge in the width direction of the coating film to the end surface 1a of the belt body 1 may be in the range of 0 to 10 mm. . It is most preferable that the outer edge of the coating film in the width direction is flush with the end surface 1a of the belt body 1 from the viewpoint of reinforcing the end, but when the distance b varies depending on the process capability. It is better to suppress this to 10 mm or less, and when the distance b becomes negative, that is, when the outer edge of the coating film in the width direction protrudes outside the end surface 1 a of the belt body 1. This is because it causes the belt to meander.

  Here, the coating film 2 can be formed only on the outer peripheral surface of the endless belt 1 as shown in FIG. 3, or the outer peripheral surface and the inner peripheral surface as shown in FIG. 4 as a sectional view of another embodiment. It can also be applied to both sides.

  Here, in order to form the endless belt of the present invention, a belt body material to be the endless belt body 1 is prepared by a known method. The belt body material is the same as that of the belt body 1 except that the width of the belt body is wider than the belt body 1 at the end by the cutting margin at both ends. Next, the coating material is applied to the end of at least one side of the belt main body material over the entire circumference. The position in the width direction to be applied is set so that a coating film having a sufficient width remains after cutting in consideration of the cutting margin at the end in the subsequent cutting process.

  After the coating film is formed, as schematically shown in a perspective view in FIG. 5, the belt body material 12 is stretched over the stretching roller 11 for the cutting process, and a pair of belt bodies 12 corresponding to both ends of the belt body material 12, respectively. Cutting to a predetermined width by the cutter 13. The purpose of this cutting step is to ensure straightness when the end surface is pressed against the guide member 4 in addition to the purpose of finishing the belt body 1 to a predetermined width.

  In addition, in order to form the coating film 2, the paint is applied with a spray gun, applied with a roll coater or the like, or is applied by immersing the end of the belt body 1 in a tank containing the paint. Can do. Furthermore, when forming the coating film 2, it can be applied directly to the belt body 1, but after the primer 3 is applied to the belt body 1, a paint may be applied onto the primer 3.

  Here, in the present invention, when an ultraviolet curable coating is used as the coating, after the coating is applied to the belt body 1, the coating is cured by irradiating the coating with ultraviolet rays and cured in a short time. This can contribute to energy savings and space saving in the drying room.

  A plurality of types of endless belts having different end configurations were produced as prototypes 1 and 2 and comparative examples 1 and 2, and the endless belts of the respective examples were attached to a belt travel device for running. In order to evaluate the durability of the endless belt, the apparatus was stopped every predetermined number of times of traveling, and the presence or absence of cracks at the end of the belt was examined. Table 1 shows the specifications of the endless belt and the durability evaluation results. In the table, the number of times of travel represents the number of times of travel at the time when the crack was found, and the end portion reinforcing means means a reinforcing tape or a coating film for reinforcing the end portions.

  Each of the prototyped endless belts had a circumference of 600 mm and a width of 240 mm, and the thickness of the belt body was 100 μm.

  As shown in the schematic diagram of FIG. 6, the belt running device used in the test is a pair of 19 mm diameter stretching rollers 5 and a guide that regulates the position in the belt width direction on one axial side of one stretching roller 5. And a member 4. Further, in order to bring the endless belt 10 to one side in the width direction, the tension force applied to the belt was set to 10N on one side and 30N on the other side. Moreover, the test conditions when the durability evaluation was performed were a temperature of 22 ° C., a humidity of 50% RH, and a traveling speed of 22 m / min.

DESCRIPTION OF SYMBOLS 1 Belt main body 2 Coating film 3 Primer 4 Guide member 5 Stretching roller

Claims (4)

In an endless belt as a toner image carrier that holds and conveys a toner image,
An endless belt, characterized in that the width direction at least one side or ultraviolet-curable resins by Li Cheng coating on both sides of one end portion is formed over the entire periphery.   The endless belt according to claim 1, wherein the thickness of the coating film is 10 to 200 μm.   The endless belt according to claim 1 or 2, wherein the coating film has a width of 1.0 to 10.0 mm.   The endless belt according to any one of claims 1 to 3, wherein the coating film is formed through a primer layer.

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