JP2008049567A - Method for producing endless belt, endless belt produced by the method, image forming device using endless belt, and apparatus for producing endless belt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an endless belt production method which can easily and surely produce an endless belt having a uniform thickness by an applicator simple in structure, the endless belt produced by the method, an image forming device using the endless belt, and an apparatus for producing the endless belt. <P>SOLUTION: The first high viscosity coating solution layer 51 is formed appropriately to have a prescribed thickness. The spiral trace 5a of the upper surface 51a of the first coating solution layer 51 which is a defect of a high viscosity coating solution layer is covered with the second coating solution layer 52 which is a low viscosity coating solution layer covering the upper surface 51a of the first coating solution layer 51 so that a coating solution layer 5 having a flat surface 5b is formed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an endless belt manufacturing method, an endless belt manufactured by this method, an image forming apparatus using the endless belt, and an endless belt manufacturing apparatus.

In an image forming apparatus such as a copying machine or a laser printer, a photoconductor for forming a toner image, an intermediate transfer body for transferring the toner image from the photoconductor to transfer the toner image to the recording paper, and a toner image transferred to the recording paper An endless belt is used in a fixing device or the like for fixing the toner, and is used as a means for conveying a toner image, recording paper, or the like. In order to form a good image, this type of endless belt is generally a thick film layer of about several tens of μm to 100 μm and is required to have a film thickness uniformity of the order of several μm.
As a method of manufacturing such an endless belt having a uniform film pressure, a cylindrical or cylindrical mold is rotated on its central axis, and the coating nozzle is scanned in parallel with the central axis of the mold while being applied to the mold surface. The coating liquid is discharged from the coating nozzle to form a spiral coating liquid layer, and then the coating liquid layer is heated and solidified to release the solidified coating liquid layer from the mold to produce an endless belt. An endless belt manufacturing method has been proposed (see, for example, Patent Document 1).
JP-A-9-85756

However, in the method described in Patent Document 1, it is difficult to form a thick film due to its fluidity when the viscosity of the coating solution is low, and conversely, when the viscosity is high, periodic film thickness fluctuations called spiral marks occur. End up. Therefore, there is a problem that it is difficult to find optimum conditions for forming a uniform film thickness, such as viscosity and mold rotation speed.
The present invention has been made in consideration of the above circumstances, and an endless belt manufacturing method capable of easily and surely manufacturing an endless belt having a uniform film thickness with a coating device having a simple structure. It is an object of the present invention to provide a manufactured endless belt, an image forming apparatus using the endless belt, and an endless belt manufacturing apparatus.

In order to solve the above-mentioned problem, the invention described in claim 1 is characterized in that a cylindrical or cylindrical mold is rotated about a central axis and a coating nozzle is scanned in parallel with the central axis of the mold while being applied to the mold surface. The coating liquid is discharged from the coating nozzle to form a coating liquid layer in a spiral shape, and then the coating liquid layer is heated and solidified, and the solidified coating liquid layer is released from the mold to produce an endless belt. In the endless belt manufacturing method, two types of coating liquids having different viscosities are used as the coating liquid, and the first coating liquid layer is formed on the mold surface with the first coating liquid having a predetermined viscosity. A second coating liquid layer is formed on the first coating liquid layer by a second coating liquid having a viscosity lower than that of the liquid.
The invention according to claim 2 is the endless belt manufacturing method according to claim 1, wherein the first coating liquid layer is a layer formed continuously on the mold surface, and the second coating liquid layer. Is characterized in that it is formed on the upper surface of the first coating solution layer as a layer.

The invention according to claim 3 is the endless belt manufacturing method according to claim 1, wherein the first coating liquid layer is a layer formed at a predetermined interval on the mold surface, The coating liquid layer fills the gap and is formed to be overlaid on at least the side surface of the first coating liquid layer.
According to a fourth aspect of the present invention, there is provided an endless belt manufactured by the endless belt manufacturing method according to any one of the first to third aspects.
The invention according to claim 5 is an image forming apparatus characterized in that the endless belt according to claim 4 is an intermediate transfer belt.

Further, the invention of claim 6 includes a cylindrical or cylindrical mold, a rotation driving means for rotating the central axis of the mold, a coating nozzle for discharging a coating liquid onto the surface of the mold, and a coating nozzle. A coating liquid supply means for supplying the coating liquid, a moving means for moving the coating nozzle along the mold surface parallel to the central axis of the mold, and a coating liquid layer formed on the mold surface is heated and solidified. In the endless belt manufacturing apparatus including a heating unit, the application nozzle includes a first application nozzle that discharges a first application liquid having a predetermined viscosity and a second viscosity that is lower than the viscosity of the first application liquid. And a second coating nozzle for discharging the coating liquid.
The invention of claim 7 is the endless belt manufacturing apparatus according to claim 6, further comprising a control means for controlling the amount of movement of the first and second coating nozzles by the moving means. .

  According to the present invention, by adopting the above configuration, an endless belt manufacturing method capable of easily and reliably manufacturing an endless belt having a uniform film thickness with a coating device having a simple structure is manufactured by this method. An endless belt, an image forming apparatus using the endless belt, and an endless belt manufacturing apparatus can be provided.

In the present invention, when an endless belt is produced by a conventional spiral coating method, there are advantages and disadvantages depending on the difference in viscosity of the coating solution used, and by combining the advantages appropriately, an endless belt with a uniform film thickness can be obtained. It has been determined that it can be easily manufactured.
First, advantages and disadvantages of an endless belt obtained by the viscosity of a coating solution used when manufacturing an endless belt by a conventional spiral coating method will be described with reference to FIGS.
FIG. 1 is a diagram illustrating a schematic configuration of a conventional coating apparatus that performs spiral coating. In the figure, reference numeral 1 denotes a cylindrical mold formed of a metal such as stainless steel or aluminum, and the rotation center shafts 2 at both ends thereof are rotatably held by holders (not shown). Reference numeral 3 denotes a rotational drive means such as a motor which is connected to one end of the central shaft 2 of the mold 1 and rotates the mold 1 in the direction of arrow A. Reference numeral 4 denotes a coating nozzle that discharges a coating liquid 6 made of a polyimide precursor solution or the like that forms the coating liquid layer 5 on the surface of the mold 1. 7 is a moving means for holding the coating nozzle 4 and moving the coating nozzle 4 along the mold surface parallel to the central axis of the mold 1, and 8 is a coating liquid supply for supplying the coating liquid 6 to the coating nozzle 4. Means 9 is a heating means such as a heater for heating and solidifying the coating solution applied on the surface 1 a of the mold 1.

  The production of an endless belt using this spiral coating apparatus will be described with reference to FIG. First, the mold 1 is rotated in the direction of the arrow A by the rotation driving means 3, and parallel to the central axis 2 of the mold 1 by the moving means 7 while discharging the coating liquid from the coating nozzle 4 to the surface 1 a of the mold 1. When the coating nozzle 4 is moved along the surface 1a of the mold 1 in the direction (arrow B direction), the coating liquid 6 is spirally formed on the surface 1a of the mold 1 as shown in FIG. Applied). In this manner, the coating liquid 6 is applied in a spiral shape with a predetermined width W to form the coating liquid layer 5 having a predetermined thickness. Then, as shown in FIG.2 (b), the coating liquid layer 5 is heated with a heating means, the solvent in the coating liquid layer 5 is volatilized and dried, and further heated, and the coating liquid layer 5 is solidified. Thereafter, the solidified coating solution layer 5 is released from the surface 1a of the mold 1 to manufacture an endless belt.

In this case, advantages and disadvantages appear in the shape of the coating liquid layer 5 obtained when the viscosity of the coating liquid used is different. FIG. 3 shows a cross-sectional shape of the coating liquid layer 6 obtained using a high-viscosity coating liquid. When a high-viscosity coating liquid is used (see FIG. 3), a relatively thick coating liquid layer 5 is easily formed. However, there is a drawback that it is difficult to form a periodic coating trace 5a in a spiral shape on the surface of the coating liquid layer 6 and to have a uniform thickness. On the other hand, when a low-viscosity coating liquid is used (see FIG. 4), since the fluidity is good, generation of the coating trace 5a can be suppressed and a flat surface 5b can be formed. There is a difficulty that it is difficult to ensure the thickness of the liquid layer 6.
In the present invention, the advantages of using the above-mentioned high-viscosity coating liquid and the advantages of the low-viscosity coating liquid are incorporated, and the relatively thick number is obtained by using the high-viscosity coating liquid and the low-viscosity coating liquid in combination. It has a coating film thickness of 10 μm to several 100 μm, and can form a coating liquid layer whose surface is flat and uniform in thickness.
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

As a first coating solution, polyamic acid was dissolved and diluted with an NN dimethylacetamide (hereinafter referred to as DMAC) solvent to prepare a polyimide precursor solution having a viscosity of 2000 P (poise). Also, a polyimide precursor solution having a viscosity of 50 P was prepared by dissolving and diluting polyamic acid with DMAC as the second coating solution.
Using these coating liquids, a coating liquid layer 6 was formed on the surface 1a of the mold 1 in accordance with the coating process flow shown in FIG. 5 using the spiral coating apparatus shown in FIG. That is, as shown in FIG. 5, first, the first coating liquid, which is a high-viscosity coating liquid, is charged and set in the coating liquid supply means 8 (step S1). Next, rotation of the mold 1 is started (step S2), and the moving means 7 is operated to move the application nozzle 4 to the application start position (step S3). Subsequently, while discharging the first coating liquid from the coating nozzle 4 (step S4), the moving means 7 is operated to scan and move the coating nozzle 4 in the direction of the arrow B so that the coating liquid is spirally formed on the mold surface 1a. And a coating liquid layer connected in the length direction (B direction) of the mold surface 1a is formed (step S5). When the coating liquid layer 5 having the predetermined width W is formed, the operation of the moving means 7 is stopped at the coating completion position, and the discharge of the coating liquid from the coating nozzle 4 is stopped (step S6). A certain first coating liquid layer 51 is formed.

  Next, the first coating liquid and the second coating liquid are exchanged in the coating liquid supply means 8 to set a low-viscosity second coating liquid (step S7). Subsequently, the coating nozzle 4 is moved to the start position of the first coating liquid layer 51 (step S8), and the second coating liquid is discharged from the coating nozzle 4 onto the upper surface 51a of the first coating liquid layer 51 (step S8). S9), the coating nozzle 4 is moved in the B direction by the moving means 7, and the second coating liquid is spirally applied on the first coating liquid layer 51 in a state of being connected and overlaid in the B direction (step S10). When the second coating liquid layer 52 is formed up to the end position of the first coating liquid layer 51, the operation of the moving means 7 is stopped and the discharge of the coating liquid from the coating nozzle 4 is stopped (Step S11). A second coating liquid layer 52 that is a viscosity coating liquid layer is formed on the upper surface of the first coating liquid layer 51.

FIG. 6 is a schematic view in which a first coating liquid layer 51 is formed on the surface 1 a of the mold 1 and a second coating liquid layer 52 is formed on the upper surface 51 a of the first coating liquid layer 51. As is apparent from this figure, the high-viscosity first coating liquid layer 51 is appropriately formed with a predetermined thickness, and the spiral of the upper surface 51a of the first coating liquid layer 51, which is a defect of the high-viscosity coating liquid layer. The coating trace 5a is covered with the second coating liquid layer 52, which is a low-viscosity coating liquid layer that covers the upper surface 51a of the first coating liquid layer 51, thereby forming the coating liquid layer 5 having a flat surface 5b. . As a result, the coating liquid layer 5 formed in this way has a uniform thickness, and an endless belt manufactured by being released from the mold has a uniform thickness.
In forming the second coating liquid layer 52 on the first and coating liquid layers 51, it is desirable that the first coating liquid layer 51 is heated in advance by the heating means 9 to volatilize the DMAC solvent and solidify to some extent. .

  Thus, after forming the 1st and 2nd coating liquid layers 51 and 52, it heats at 350 degreeC with the heating means 9, raises the imidation reaction of a polyimide precursor, and finally these coating liquid layers 51 , 52 are integrated and solidified (step S12). Thereafter, the coating liquid layer 5 is released from the mold 1 to obtain an endless belt. The endless belt thus obtained had a uniform thickness and was good as an intermediate transfer belt used in an image forming apparatus, as will be described later.

In this example, a polyimide precursor was used as the coating solution. However, not only the polyimide precursor but also a heat-resistant rubber material such as polyamideimide resin, silicon, and urethane, and an inorganic system such as carbon black and silica. What mixed additives, such as a filler, may be used.
In addition, the viscosity of the coating solution can be adjusted to a desired viscosity by appropriately adjusting the addition amount of the dispersant and the solvent, but the first coating solution is used with a viscosity of 1000 P or more and 15000 P or less. The second coating liquid is preferably a viscosity in the range of 100P to 10P.
Further, in the present embodiment, the mold 1 is the columnar mold 1, but is not limited to the columnar body, and may be a cylindrical body.

Next, a method for manufacturing an endless belt according to another embodiment of the present invention will be described. In the present embodiment, in step S5 of the coating process shown in FIG. 5 of the above-described first embodiment, the movement interval of the coating nozzle 4 in the B direction is increased, and the first coating liquid layer 51 is formed with a predetermined interval 10 formed. In addition, the same process is basically employed except that the second coating liquid is applied within the interval 10 in step S10. As a result, the obtained coating liquid layer 5 is configured such that the second coating liquid layer 52 is superimposed on the side surface 51b of the first coating liquid layer 51 as shown in FIG. In the coating liquid layer 5 thus obtained, the first coating liquid layer 51 can easily and reliably form the coating liquid layer 5 having a predetermined thickness, and has a low viscosity second liquid with good fluidity. Thus, the coating liquid layer 5 having a flat surface can be obtained in a state where the thickness of the first coating liquid layer 51 is maintained. As a result, an endless belt having a uniform thickness can be manufactured easily and reliably.
In addition, as described above, as the method for producing the interval 10, as described above, the spiral first and second coating liquid layers are not formed as one spiral coating liquid layer, but a plurality of spiral first coating liquid layers. Even when the second coating liquid layers 51 and 52 are formed, the same operation and effect can be obtained.

  That is, as shown in the flow of the coating process of FIG. 8, when the first coating liquid layer is formed, by repeating the return process from step S6 to step S3, a plurality of lines having predetermined intervals 101 and 102 are obtained. Spiral coating liquid layers 511 and 512 are formed. Then, when the second coating liquid layer is formed in the intervals 101 and 102, the second coating liquid is filled in the intervals 101 and 102 by repeating the return process from step S11 to step S8. Coating liquid layers 521 and 522 are formed. The coating liquid layer 5 thus obtained has a structure as shown in FIG. 9, and the same operation and effect as those shown in FIG. 7 are obtained. In the case of forming the coating liquid layer 5 in this way, there is an advantage that the second coating liquid layer can be appropriately produced even if the first coating liquid layer is formed with a relatively wide interval. Have.

FIG. 10 is a diagram showing a schematic configuration of an endless belt manufacturing apparatus according to an embodiment of the present invention. The basic configuration of the endless belt manufacturing apparatus according to the present embodiment is the same as that of the spiral coating apparatus shown in FIG. 1 described above.
The endless belt manufacturing apparatus according to the present embodiment includes a first application nozzle 41 that discharges the first application liquid used in the first embodiment as the application nozzle 4 in the spiral application apparatus shown in FIG. A second coating nozzle 42 for discharging two coating liquids, and a first coating liquid supply means 81 and a second coating liquid for supplying the first coating liquid and the second coating liquid to the coating nozzles 41 and 42, respectively. A supply unit 82 and a control device for controlling the discharge timing of each of the coating liquids from the coating liquid supply units 81 and 82 and the amount of movement of the coating nozzles 41 and 42 of the moving unit 7 are provided. Is different. Thus, by using the first and second dedicated coating nozzles 41 and 42 and the feeding devices 81 and 82 as the coating nozzle and the coating solution supply device, the first coating solution to the feeding device and Since the replacement operation of the second coating liquid is not necessary, not only can the coating be performed more quickly, but also the advantage that the coating liquid layer structure of the above-described Example 2 can be manufactured easily and quickly.

That is, it is possible to produce the coating liquid layer structure shown in FIG. 6 of Example 1 using this manufacturing apparatus, but as shown in FIGS. 7 and 9 shown in Example 2 described above. , The interval 10 between the first coating liquid layer 51 and the intervals 101 and 102 between the first spiral first coating liquid layer 511 and the second spiral first coating liquid layer 512 are second. This is particularly effective when the coating liquid layers 52, 521, and 522 are applied and formed. That is, if the second coating liquid is applied within the interval 10, 101, 102 after the first coating liquid layer 51 is formed with a slight delay (time lag) in time, the endlessly more quickly and endlessly. Belts can be produced and desirable results are obtained. In particular, when one spiral first coating liquid layer is formed and the second coating liquid layer is formed within this interval, it is only necessary to scan the coating nozzles 41 and 42 once, which is quicker. This is effective because the coating liquid layer 5 can be formed.
In the endless belt manufacturing apparatus of the present embodiment, a heating means 9 for solidifying the coating liquid layer 5 is attached. This heating means 9 is a heating for removing the solvent in the coating liquid. As a heating means used only as a means, using the polyimide precursor solution as described above, and causing an imidization reaction of this polyimide precursor, heating different from the heating means 9 of the coating means of this embodiment is used. Means can be used.

In this embodiment, an image forming apparatus using the endless belt obtained in the first to third embodiments as an intermediate transfer belt of the image forming apparatus is shown. FIG. 11 shows a schematic configuration of a main part of the image forming apparatus according to the present embodiment. In the figure, 20Y, 20C, 20M, and 20K rotate in the direction of the arrow C to form yellow, cyan, magenta, and black toner images, respectively, and 21 is obtained in the first to third embodiments. This is an intermediate transfer belt made of an endless belt.
In this image forming apparatus, an image latent image is formed by the photosensitive drums 20Y, 20C, 20M, and 20K by exposure from an exposure device (not shown), and the image latent image is converted into a toner image of each color with each color toner by a developing device (not shown). Form. Subsequently, the toner images carried on the photosensitive drums 20Y, 20C, 20M, and 20K are suspended on the driving roller 22 and the driven roller 23, and are first transferred to the intermediate transfer belt 21 that is rotationally driven in the direction of arrow D. Transferred by rollers 24Y, 24C, 24M, and 24K. The toner image transferred onto the intermediate transfer belt 21 is transferred onto the paper 26 conveyed between the second transfer roller 25 and the intermediate transfer belt 21 by the second transfer roller 25. Thereafter, the paper 26 holding the toner image is heated and pressurized by a fixing device (not shown) such as a pressure roller and a heating roller, and the toner image is fixed on the paper 26 and discharged.

  In such an image forming apparatus, since the intermediate transfer belt 21 having a uniform thickness manufactured by the method described in the first to third embodiments is used, dot positions caused by toner transfer performance and belt drive speed unevenness are used. It is possible to form a high-quality image by suppressing deviation and the like.

It is a perspective view which shows schematic structure of the conventional spiral coating apparatus. It is a perspective view which shows formation of the coating liquid layer formed on the metal mold | die by the conventional spiral coating apparatus, (a) is a perspective view which shows the state in the middle of application | coating, (b) is a perspective view which shows the state at the time of application completion It is. It is sectional drawing of the coating liquid layer part at the time of using the high-viscosity coating liquid formed with the conventional spiral coating apparatus. It is sectional drawing of the coating liquid layer part at the time of using the low-viscosity coating liquid formed with the conventional spiral coating apparatus. It is a flowchart which shows the application | coating process shown in Example 1 by this invention. It is sectional drawing of the coating liquid layer obtained by the application | coating process shown in Example 1 by this invention. It is sectional drawing of the coating liquid layer obtained in Example 2 by this invention. It is a flowchart which shows the application | coating process of other embodiment which concerns on Example 2 by this invention. It is sectional drawing of the coating liquid layer of other embodiment which concerns on Example 2 by this invention. It is a perspective view which shows schematic structure of the manufacturing apparatus of the endless belt shown in Example 3 by this invention. It is a side view which shows schematic structure of the principal part of the image forming apparatus shown in Example 4 by this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Mold, 2 Central axis, 3 Rotation drive means, 4 Application nozzle, 41 1st application nozzle, 42 2nd application nozzle, 5 Application liquid layer, 5a Application trace, 5b Flat surface, 51, 511, 512 1st Coating liquid layer, 51a upper surface, 51b side surface, 52, 521, 522 second coating liquid layer, 6 coating liquid, 7 moving means, 8, 81, 82 coating liquid supply means, 9 heating means, 10 control device, 11 interval, 20Y, 20C, 20M, 20K Photosensitive drum, 21 Intermediate transfer belt, 22 Drive roller, 23 Driven roller, 24Y, 24C, 24M, 24K Primary transfer roller, 25 Secondary transfer roller, 26 Paper

Claims (7)

A cylindrical or cylindrical mold is rotated around the central axis and the coating nozzle is scanned in parallel with the central axis of the mold while discharging the coating liquid from the coating nozzle onto the mold surface to form a coating liquid layer in a spiral shape. In an endless belt manufacturing method for manufacturing and forming an endless belt by heating and solidifying the coating liquid layer and releasing the solidified coating liquid layer from the mold,
Two coating liquids having different viscosities are used as the coating liquid, and after forming a first coating liquid layer on the mold surface with the first coating liquid having a predetermined viscosity, the viscosity is lower than the viscosity of the first coating liquid. A method for producing an endless belt, comprising: forming a second coating liquid layer with a second coating liquid on the first coating liquid layer. The endless belt manufacturing method according to claim 1,
The first coating liquid layer is a layer formed continuously on the mold surface, and the second coating liquid layer is formed so as to be superimposed on the upper surface of the first coating liquid layer. An endless belt manufacturing method. The endless belt manufacturing method according to claim 1,
The first coating liquid layer is a layer formed at a predetermined interval on the mold surface, and the second coating liquid layer fills the interval, and at least the first coating liquid layer A process for producing an endless belt, characterized in that the endless belt is formed on a side surface of the belt.   An endless belt manufactured by the endless belt manufacturing method according to any one of claims 1 to 3.   An image forming apparatus, wherein the endless belt according to claim 4 is an intermediate transfer belt. A cylindrical or cylindrical mold, a rotation drive unit that rotates the central axis of the mold, a coating nozzle that discharges the coating liquid onto the surface of the mold, and a coating liquid supply unit that supplies the coating liquid to the coating nozzle An endless belt comprising: a moving unit that moves the coating nozzle along the mold surface parallel to the center axis of the mold; and a heating unit that heats and solidifies the coating liquid layer formed on the mold surface. In manufacturing equipment,
The application nozzle includes a first application nozzle that discharges a first application liquid having a predetermined viscosity, and a second application nozzle that discharges a second application liquid having a lower viscosity than the viscosity of the first application liquid. An endless belt manufacturing apparatus. In the manufacturing apparatus of the endless belt of Claim 6,
An apparatus for manufacturing an endless belt, comprising control means for controlling the amount of movement of the first and second coating nozzles by the moving means.

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