JP2007136429A - Circular body, coating apparatus, coating method and method for manufacturing endless belt by using the apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circular body the inside diameter of whose hole can be adjusted according to the outside diameter of a core body even when the circular body is neither pulled out of a coating liquid nor exchanged for the new one, to provide a coating apparatus and a coating method in each of which the circular body is used and to provide a method for manufacturing an endless belt by using the coating apparatus and the coating method. <P>SOLUTION: The circular body 20 for applying the coating liquid is composed of a main body 21 of the circular body and an inside diameter adjusting member 22 to be arranged on the upper surface of the main body 21. A circular hole 22A having a minimum inside diameter portion of the circular body 20 is arranged in the inside diameter adjusting member 22 so that the thickness of a coating film 12A to be formed on the core body 10 is regulated by the size of the inside diameter of the circular hole. In other words, the circular hole 22A having the predetermined inside diameter regulated according to the outside diameter of the core body 10 is arranged in the inside diameter adjusting member. The inside diameter adjusting member 22 is set in a concave part 21B of the main body 21, positioned and fixed by screws 24. As a result, when the inside diameter adjusting member is changed, the inside diameter of the circular hole of the circular body can be adjusted according to the outside diameter of the core body even when the main body 21 is neither pulled out of the coating liquid nor exchanged for the new one. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to, for example, a coating apparatus and a coating method using an annular body that can form a coating film uniformly. Moreover, it is related with the cyclic | annular body applicable to a coating device and the coating method. Furthermore, it is related with the manufacturing method of the endless belt using a coating device and the coating method. The endless belt is particularly preferably used as an intermediate transfer belt of an image forming apparatus using an electrophotographic system such as a copying machine or a printer.

  In an electrophotographic apparatus, a rotating body made of metal, resin, or rubber is used for a photoreceptor, a transfer body, a fixing body, etc., but the rotating body can be deformed for downsizing or high performance of the apparatus. In some cases, a resin belt having a small thickness is used. The material is preferably a polyimide (hereinafter abbreviated as PI) resin or a polyamideimide (hereinafter abbreviated as PAI) resin in terms of strength, dimensional stability, heat resistance and the like. In this case, if there is a seam in the belt, a defect due to the seam occurs in the output image. Therefore, an endless belt without a seam is preferable.

  As a method of manufacturing an endless belt, a method of applying a film-forming resin solution to the surface of a cylindrical core body by a dip coating method, drying, heating and reacting as necessary, and then peeling the resin film from the core body There is also. However, when the film-forming resin is PI or PAI, the viscosity of the solution is very high. Therefore, when the film is formed on the core by the dip coating method, the film thickness becomes too thick. Therefore, a method of controlling the film thickness by an annular body as disclosed in Patent Document 1 and Patent Document 2 can be applied.

  Specifically, when coating is performed using an annular body, the core body is coated with the longitudinal direction vertical. An annular sealing material having a hole slightly smaller than the outer diameter of the core body is provided at the bottom of the annular coating tank, the core body is inserted through the center of the annular sealing material, and the solution is stored in the annular coating tank. Thereby, the solution does not leak. At the time of application, another core body is connected under the core body and pushed upward from the lower part of the annular coating tank to form a coating film on the surface of the core body. The other core may be an intermediate that does not produce a belt.

  The thickness of the coating film is regulated by the gap between the core and the circular hole of the annular body, but by lifting the annular body during application, it acts so that the shearing force is uniform between the annular body and the core body. Since the annular body 20 is automatically aligned, the distance between the annular body and the core body is kept constant over the entire circumference, and a belt having a uniform film thickness can be obtained.

  When coating with a coating apparatus using such an annular body, if the outer diameter of the core body is constant, the gap between the outer diameter of the core body and the circular hole of the annular body is also constant. However, the actual outer diameter of the core is not always constant and varies depending on manufacturing errors.

  For example, when the surface of the core body is scratched, the surface of the core body is shaved and corrected, but in this case, the outer diameter of the core body is reduced.

  When the outer diameter of the core body is reduced, the film thickness changes, for example, the coating film becomes thicker. If it is within the acceptable range, it will not cause quality problems, but if it exceeds, measures are required.

  Conventionally, an annular body having a different inner diameter was exchanged according to the outer diameter of the core body. However, the annular body is expensive in order to manufacture with high accuracy, and a number of these are prepared. This is not preferable because it increases costs. Therefore, as in Patent Document 2, a method has also been proposed in which a gap adjusting member is provided on the annular body and only a part of the annular body is replaced.

  However, in order to replace the annular body, when removing the annular body from the solution, air bubbles are mixed into the solution. It took man-hours, such as the need to clean the body.

  For this reason, there has been a demand for a method capable of adjusting the film thickness without removing the annular body from the solution.

JP 2002-91027 A JP 2004-237261 A

  Accordingly, an object of the present invention is to provide an annular body in which the inner diameter of the hole of the annular body can be adjusted in accordance with the outer diameter of the core body without taking it out from the coating liquid and replacing it. Moreover, it aims at providing the coating device and coating method using the same. Furthermore, it aims at providing the manufacturing method of an endless belt using a coating device and the coating method.

The above problem is solved by the following means. That is,
The annular body of the present invention is an annular body provided with a hole having an inner diameter larger than the outer diameter of the core body to which the coating liquid is applied and is floated on the coating liquid, and is immersed in the coating liquid stored in the coating tank. An annular body for applying the coating liquid onto the surface of the core body by allowing the core body to be vertically raised from the coating liquid and passing through the hole with the axial direction of the core body vertical. ,
It is characterized by comprising an annular body main body and an inner diameter adjusting member which is disposed on the upper surface of the annular body main body and has a hole with a predetermined inner diameter corresponding to the outer diameter of the core body.

  In the annular body of the present invention, the inner diameter adjusting member having a hole with a predetermined inner diameter that defines the film thickness of the coating film is disposed in the annular body main body, so that the inner diameter adjusting member is floated in a state where the annular body is floated on the coating liquid. Can be installed and removed. For this reason, the inner diameter of the hole of the annular body can be adjusted according to the outer diameter of the core body without taking it out from the coating liquid and replacing it. The cleaning work of the annular body becomes unnecessary.

On the other hand, the coating apparatus of the present invention includes a coating tank for storing the coating liquid, an annular body provided with a hole having an inner diameter larger than the outer diameter of the core body to which the coating liquid is applied, and floated on the coating liquid. The core body immersed in the coating liquid stored in the coating tank is caused to pass through the hole by being relatively raised from the coating liquid with the axial direction of the core body vertical. An application device for applying a coating liquid to a body surface,
The annular body is the above-described annular body of the present invention.

Further, the coating method of the present invention includes a coating tank for storing the coating liquid, an annular body provided with a hole having an inner diameter larger than the outer diameter of the core body to which the coating liquid is applied, and floated on the coating liquid. The core body immersed in the coating liquid stored in the coating tank is caused to pass through the hole while being relatively elevated from the coating liquid with the axial direction of the core body vertical. By the application method of applying a coating liquid to the core surface,
The annular body is the annular body according to claim 1, wherein the inner diameter adjusting member is replaced while the annular body is floated according to the outer diameter of the core body.

  Moreover, the manufacturing method of the endless belt according to the present invention is such that after the coating liquid for film formation is applied to the surface of the core body using the coating apparatus according to the present invention, any one of drying, heat curing, baking, or all A film is formed by performing a treatment, and the film is removed from the core.

  ADVANTAGE OF THE INVENTION According to this invention, even if it takes out from a coating liquid and does not replace | exchange, the annular body which can adjust the internal diameter of the hole of an annular body according to the outer diameter of a core can be provided. Moreover, a coating apparatus and a coating method using the same can be provided. Furthermore, the manufacturing method of the endless belt using a coating device and the coating method can be provided.

  The present invention will be described with reference to the drawings. In addition, what has the substantially same function is attached | subjected and demonstrated through the whole figure, and the description may be abbreviate | omitted depending on the case.

  FIG. 1 is a schematic configuration diagram showing a coating apparatus according to an embodiment of the present invention when it is stopped. FIG. 2 is a schematic configuration diagram showing the time of application of the application apparatus according to the embodiment of the present invention. FIG. 3 is a schematic cross-sectional view showing an annular body according to an embodiment of the present invention. FIG. 4 is an exploded perspective view showing an annular body according to the embodiment of the present invention. However, FIG.1 and FIG.2 shows with a partially broken sectional view, and shows only the principal part, The core holding mechanism and other apparatuses are abbreviate | omitted.

  As shown in FIG. 1, the coating apparatus according to the present embodiment includes an annular coating tank 11 and an annular body 20 for storing the coating liquid 12. An annular sealing material 13 having a hole slightly smaller than the outer diameter of the core body is provided at the bottom of the annular coating tank 11, and the core body 10 is fitted into the hole so that the core body is immersed in the coating liquid 12. The leakage of the coating liquid 12 is prevented.

  As shown in FIGS. 3 and 4, the annular body 20 includes an annular body main body 21 and an inner diameter adjusting member 22 disposed on the upper surface of the annular body main body 21. The top surface of the annular body 21 is a surface that is a non-contact area with the coating liquid 12 and has the opening 21 </ b> A of the annular body 21 when the annular body 21 is floated on the coating liquid 12.

  The annular body 21 has an opening 21A larger than the circular hole 22A of the inner diameter adjusting member 22, and the inner diameter of the opening 21A is gradually reduced from the lower part to the upper part immersed in the coating liquid. The inner wall surface constituting the opening 21A may be stepped or curved in addition to a linear inclined surface. The annular body 21 may have a hollow structure.

  On the side wall of the annular body 21, four rod-like arms 23 extending to the upper edge of the annular coating tank 11 are arranged at equal intervals along the circumferential direction (of course, not limited to this number). The annular body 20 is prevented from sinking into the coating liquid 12 by the arm 23 coming into contact with the upper edge of the side wall of the annular coating tank 11.

  The annular body 21 has a concave portion 21B for fitting the inner diameter adjusting member 22 on the upper surface which is a non-immersed portion in the coating liquid, and for positioning and fixing the inner diameter adjusting member on the bottom surface of the concave portion 21B. Screw holes 21C are provided.

  The material of the annular body 21 is preferably selected from metals and plastics that are not attacked by the solvent of the coating liquid 12.

  On the other hand, the inner diameter adjusting member 22 is formed of a disk having an outer diameter smaller than the outer diameter of the annular body main body 21 and a thickness of about 0.1 to 10 mm, and a minimum inner diameter portion of the annular body 20 at the center thereof. It has a circular hole 22A. The film thickness of the coating film 12A on the core body 10 is defined by the size of the inner diameter of the circular hole 22A. In other words, the inner diameter adjusting member is provided with a circular hole 22A having a predetermined inner diameter corresponding to the outer diameter of the core body 10.

  The inner diameter adjustment member 22 is provided with a screw hole 22B for positioning and fixing to the annular body. The inner diameter adjusting member 22 is fitted into the recess 21 </ b> B of the annular body 21 and is aligned and fixed by a screw 24. Although not shown in the drawings, positioning of the annular body 21 and the inner diameter adjusting member 22 can be easily performed by, for example, providing a hole for a knock pin in advance and positioning with a knock pin.

  The material of the inner diameter adjusting member 22 is preferably selected from metals and plastics that are not affected by the solvent of the coating liquid 12. Note that the material of the inner diameter adjusting member 22 may be the same as or different from the material of the annular body 21.

  As described above, the annular body 20 is detachably disposed with the inner diameter adjusting member 22 having the circular hole 22A having a predetermined inner diameter according to the outer diameter of the core body 10.

  Further, in the annular body 20, the relationship between the inner diameter and the outer diameter of the inner diameter adjusting member 22 is adjusted, and even when the inner diameter is different, the weight is constant, so that the annular body can be applied even to the core body having different diameters. If the total weight of 20 and the inner diameter adjusting member 22 can be easily made constant and the same coating solution is used, the coating is performed under the same conditions without changing the coating conditions for each core having a different diameter. It is possible. Furthermore, by controlling the weight of the inner diameter adjusting member 22, the optimum coating speed (speed for pulling up the core body 10) can be changed, and an optimum configuration can be obtained according to production conditions.

  Such a coating apparatus is called an annular coating apparatus, and has an advantage that a smaller amount of coating liquid is required than the dip coating method. Furthermore, although not shown in the coating apparatus of the present invention according to the present embodiment. You may have the core body holding means which hold | maintains the core body 10, the 1st moving means which moves this holding means to an up-down direction, and / or the 2nd moving means to move an application tank up and down.

  In order to apply the coating liquid 12 to the surface of the core body 10 using the coating apparatus according to the present embodiment, the core body 10 is passed through the annular coating tank 11 and the coating liquid 12 is added, as shown in FIG. Another other core 10 </ b> A is placed under the core 10 and is relatively raised from the coating liquid 12. The rising speed at that time is preferably 0.1 to 1.5 m / min.

  “Applying the coating liquid to the surface of the core” means applying to the surface of the outer peripheral surface of the core and the surface of the layer when the surface has a layer. Further, “raising the core” is a relative relationship with the liquid level during application, and includes the case of “stopping the core and lowering the coating liquid”.

  When the core body 10 is raised from the coating liquid 12, the annular body 20 is lifted by the frictional resistance due to the viscosity of the coating liquid. Since the annular body 20 is freely movable in the horizontal direction, the frictional resistance between the core body 10 and the annular body 20 is constant in the circumferential direction, that is, the surface of the core body 10 and the circular hole of the annular body 20. The annular body 20 moves so that the gap is uniform, and the coating film 12 </ b> A having a uniform film thickness is formed on the core body 10.

  In this way, since the film thickness is regulated by the annular body 20, a highly viscous solution can be used, and since the coating film hangs down due to gravity at the upper end of the core body 10, the film thickness can be reduced both in the circumferential direction and in the axial direction. It can be made uniform.

  Here, since the film thickness of the coating film 12A is determined by the gap between the outer diameter of the core body 10 and the circular hole 22A of the annular body 20 (inner diameter adjusting member 22), the diameter of the circular hole is adjusted by the desired film thickness. To do. This can be easily performed by replacing the inner diameter adjusting member 22.

  In the coating apparatus according to the present embodiment described above, by using the annular body 20 in which the inner diameter adjusting member 22 having a predetermined inner diameter hole that defines the film thickness of the coating film 12A is disposed on the upper surface of the annular body main body 21, The inner diameter adjusting member 22 can be attached and detached while the annular body 20 is floated on the coating liquid 12. Therefore, the inner diameter of the circular hole of the annular body 20 can be adjusted according to the outer diameter of the core body 10 without removing the annular body 20 from the coating liquid 12 and replacing it, and bubbles are mixed in the coating liquid 12. Or shortening the application stop time or cleaning the annular body 20 becomes unnecessary.

  In the annular body 20, the mechanism for detaching the inner diameter adjusting member 22 from the annular body main body 21 is not limited to the above, and is a non-immersed part of the annular body main body 21 in the coating liquid. It is only necessary that the inner diameter adjusting member 22 can be attached and detached while floating (while immersed).

  Hereinafter, each member of the coating device according to the embodiment of the present invention will be described in detail.

  The core body 10 is preferably a metal cylinder such as aluminum, stainless steel, nickel, or copper. In addition, when manufacturing an endless belt as will be described later, the axial length of the core body needs to be longer than the width of the target endless belt, but there is a margin for the ineffective region generated at the end. In order to ensure, it is preferable that it is 10 to 40% longer than the width of the target endless belt. The outer diameter of the core body is adjusted to the diameter of the target endless belt, and the thickness is set to a thickness that can maintain the strength of the core body.

  Further, although not shown, a holding plate for holding the core body 10 may be attached to both ends of the core body 10. The holding plate may have an arbitrarily shaped ventilation hole, a hole through which a mandrel passes in the center, or a shaft. Moreover, you may attach components for hanging or mounting.

  Moreover, in order to prevent the film | membrane formed from adhering to the core body surface, the core body 10 is good to provide a mold release property to the surface of a core body. For this, there are methods of coating the core surface with a fluororesin or silicone resin, or applying a release agent to the core surface.

  Depending on the type of the coating liquid 12, in the production of an endless belt, which will be described later, there are solvent volatiles during heating and gas generated during reaction, and the resin film after heating partially swells due to the generated gas. May occur. This may occur particularly when a PI precursor solution is used as the coating liquid and the film thickness exceeds 50 μm.

  In order to prevent the above-described swelling, it is preferable to roughen the core surface to Ra 0.2 to 2 μm as described in JP-A-2002-160239. Examples of the roughening method include blasting, cutting, sandpaper peeling, and the like. Thereby, the gas generated from the coating film can go out through a slight gap formed between the core and the coating film, and does not swell.

  As the coating liquid 12, as will be described later, when an endless belt is further produced, a PI precursor solution or a PAI resin solution is preferably used. Various known precursors can be used as the PI precursor and PAI resin. The concentration, viscosity, and the like of the PI precursor or PAI resin solution are appropriately selected. The solid content concentration of the solution preferably used is 10 to 40% by mass, and the viscosity is 1 to 100 Pa · s. The solvent of the coating liquid is an aprotic polar solvent such as N-methylpyrrolidone, N, N-dimethylacetamide, or acetamide, but these easily absorb moisture in the air. If the coating liquid absorbs moisture, the resin component in the coating liquid may precipitate and become cloudy, or the PI precursor or PAI resin may be hydrolyzed, so care must be taken. In addition, the PI precursor is strongly colored due to the influence of oxygen, the viscosity is changed, and the condensation reaction may be difficult to occur. In the present invention, these are prevented by injecting an inert gas into the coating tank.

Hereinafter, the manufacturing method of the endless belt of the present invention will be described in detail.
In order to produce an endless belt using the coating apparatus of the present invention, the coating liquid for film formation is applied to the surface of the core described above, and then any one of drying, heat curing, baking, or all treatments is performed. Forming a film and removing the film from the core.

  Next, the method for producing an endless belt according to the present invention will be described in the case where a PI precursor solution or a PAI resin solution is used as the coating liquid.

In the production of an endless belt, the coating film coated with the coating liquid for coating is heated using the coating apparatus of the present invention, the solvent present in the coating film is removed, and the coating film is dried to the extent that the coating film is not deformed. . The heating conditions are preferably 90 to 170 ° C. and 20 to 60 minutes. At that time, the higher the temperature, the shorter the heating time, and the temperature may be raised stepwise or at a constant rate.
Further, when dripping occurs in the coating film during heating, it is effective to make the longitudinal direction of the core body horizontal and rotate it slowly. In that case, it is preferable to put the mandrel through the hole of the holding plate and put it in the dryer in a state of being placed on the turntable. When the film forming solution is a PAI resin solution, the film can be obtained only by drying the solvent.

  On the other hand, in the case where the film forming solution is a PI precursor solution, if the solvent is removed too much from the coating film, the coating film does not yet maintain strength, and thus cracking is likely to occur. Therefore, it is preferable to leave a certain amount of solvent (15 to 45% by mass in the PI precursor film). In the case where the film forming solution is a PI precursor solution, the PI precursor film is then heated at 250 to 450 ° C., preferably at 280 to 350 ° C. for 20 to 60 minutes to cause a condensation reaction. A film is formed. At that time, the temperature may be increased stepwise.

  The film formed as described above becomes an endless belt by peeling from the core after cooling. The endless belt may be further subjected to drilling or ribbing as necessary.

When the endless belt is used as a transfer belt or a contact charging belt, a conductive substance is dispersed in the film forming solution. Examples of the conductive material include carbon-based materials such as carbon black, carbon fiber, carbon nanotube, and graphite, metals or alloys such as copper, silver, and aluminum, tin oxide, indium oxide, antimony oxide, SnO ₂ —In ₂ O. ₃ Conductive metal oxides such as complex oxides. As described above, when the film contracts, the resistance value becomes uneven, but by preventing the contraction, the resistance value can be made uniform.

  The film thickness of the endless belt preferable for these uses is about 30 to 150 μm.

(Test example)
The following tests were conducted.
-Test Example 1
Carbon black (trade name: Special Black 4, Degussa Huls) mixed with PI precursor solution (trade name: U Varnish A, manufactured by Ube Industries, concentration 18%) at a solid content mass ratio of 23%, then facing collision Dispersed with a mold disperser. Furthermore, a silicone leveling agent (trade name: DC3PA, manufactured by Dow Corning Tore Silicone) was added so that the concentration became 500 ppm to prepare a coating solution.

  Separately, ten aluminum cylinders having an outer diameter of 366 mm, a thickness of 10 mm, and a length of 450 mm were prepared. When the average value obtained by measuring the outer diameters at five locations was taken as the outer diameter, the outer diameter varied by 366 ± 0.02 m. The surface was roughened to Ra 1.0 μm by blasting with spherical alumina particles. In addition, a holding plate having a thickness of 15 mm, an outer diameter that fits into the cylinder, four 100 mm diameter vent holes, and a 20 mm diameter hole in the center is made of the same aluminum material, and fitted into the cylinder. Welded by TIG welding.

  A silicone release agent (trade name: Sepacoat, manufactured by Shin-Etsu Chemical Co., Ltd.) was applied to the surface of the cylinder. A polyester adhesive tape having a width of 10 mm was wound around the end of the core. This is to prevent the coating film from wrapping around the side surface of the core.

  Next, using the coating liquid, a PI precursor coating film is formed by the annular coating apparatus according to the embodiment (FIGS. 1 and 2; however, the following annular body is applied to the annular body). As an annular body, an aluminum body having an outer diameter of 420 mm, an inner diameter of 367.1 mm at the smallest part of the circular hole, and a height of 50 mm was produced. The inner wall was linearly inclined, and the inclination angle with respect to the vertical line was 10 °. A 4 mm portion parallel to the core was formed at the upper end.

  On the other hand, a hole with an inner diameter of 386 mm was made in the bottom surface of an annular coating tank having an inner diameter of 450 mm and a height of 100 mm. An inclined surface with an angle of 10 ° was formed on the bottom surface. Further, an annular sealing material made of hard polyethylene resin having a thickness of 0.5 mm and having a hole with an inner diameter of 364.5 mm was attached to the back surface of the bottom surface, and a core body was passed through the center. 3 kg of the PI precursor solution was placed in the annular coating tank, and the annular body was placed.

  Next, another core body was placed under the core body and applied by pushing up at 0.8 m / min (see FIG. 2). At that time, the annular body was lifted about 50 mm. Thereby, a PI precursor coating film having a wet film thickness of about 500 μm was formed on the core.

  A 20 mmφ stainless steel shaft is passed through the center hole of the holding plate of the core body, placed on a turntable, leveled, and heated at 80 ° C. for 20 minutes and at 130 ° C. for 30 minutes while rotating at 6 rpm, PI precursor The coating film was dried. As a result, a PI precursor film having a thickness of about 150 μm was obtained. At this point, the adhesive tape at the end of the core was removed.

  Next, the core body was made vertical, the shaft was removed, and it was placed on a table, put in a heating device, and heated and reacted at 200 ° C. for 30 minutes and 340 ° C. for 30 minutes to form a PI resin film.

  After cooling to room temperature, the film was extracted from the core while blowing air between the core and the film to obtain an endless belt. In addition, there were no bubbles in the film and no stripes in the axial direction. The endless belt was cut at about 35 mm from both ends to obtain an endless belt having a width of 360 mm.

The obtained endless belt has a semiconductivity of about 10 ¹⁰ Ωcm when the volume resistivity is measured at 100 V, and the film thickness is 80 ± 1.5 μm, and a desired film thickness is obtained. It could be used as a photographic transfer belt.

-Test Example 2-
A die that was not usable due to scratches or the like on the surface of the core was recut to prepare 10 aluminum cylinders having an outer diameter of 365.8 mm, a wall thickness of 9.5 mm, and a length of 450 mm. When the average value obtained by measuring the outer diameters at five locations was taken as the outer diameter, the outer diameter varied by 365.8 ± 0.02 m.

  Further, the same coating liquid as in Test Example 1 was facilitated.

  Next, using the coating liquid, a PI precursor coating film is formed by the annular coating apparatus according to the embodiment (see FIGS. 1 and 2). As an annular body, an aluminum annular body having an outer diameter of 420 mm, an inner diameter of 367.1 mm at the minimum of the circular hole, and a height of 50 mm is floated on the coating liquid, and an outer diameter of 420 mm and an inner diameter of 366 are placed on the upper surface (upper end). An inner diameter adjusting member having a thickness of 9 mm and a thickness of 4 mm was attached to the annular body and fixed with screws (see FIGS. 3 and 4).

  On the other hand, a hole with an inner diameter of 386 mm was made in the bottom surface of an annular coating tank having an inner diameter of 450 mm and a height of 100 mm. An inclined surface with an angle of 10 ° was formed on the bottom surface. Further, an annular sealing material made of hard polyethylene resin having a thickness of 0.5 mm and having a hole with an inner diameter of 364.5 mm was attached to the back surface of the bottom surface, and a core body was passed through the center. 3 kg of the PI precursor solution was placed in the annular coating tank, and the annular body was placed.

  Next, another core body was placed under the core body, and the coating was performed by pushing up at 0.8 m / min. At that time, the annular body was lifted about 50 mm. Thereby, a PI precursor coating film having a wet film thickness of about 500 μm was formed on the core.

  A 20 mmφ stainless steel shaft is passed through the center hole of the holding plate of the core body, placed on a turntable, leveled, and heated at 80 ° C. for 20 minutes and at 130 ° C. for 30 minutes while rotating at 6 rpm, PI precursor The coating film was dried. As a result, a PI precursor film having a thickness of about 150 μm was obtained. At this point, the adhesive tape at the end of the core was removed.

  Next, the core body was made vertical, the shaft was removed, and it was placed on a table, put in a heating device, and heated and reacted at 200 ° C. for 30 minutes and 340 ° C. for 30 minutes to form a PI resin film.

  After cooling to room temperature, the film was extracted from the core while blowing air between the core and the film to obtain an endless belt. In addition, there were no bubbles in the film and no stripes in the axial direction. The endless belt was cut at about 35 mm from both ends to obtain an endless belt having a width of 360 mm.

The obtained endless belt has a semiconductivity of about 10 ¹⁰ Ωcm when the volume resistivity is measured at 100 V, and the film thickness is 80 ± 1.5 μm, and a desired film thickness is obtained. It could be used as a photographic transfer belt.

-Test Example 3-
A belt was produced in the same manner as in Test Example 1 except that the regenerated core used in Test Example 2 was used. That is, the outer diameter of the mold is 365.8 ± 0.02 mm, and the inner diameter of the annular body is 367.1 mm.

  The film thickness of the obtained endless belt was 94.5 ± 1.5 μm, and a desired film thickness could not be obtained, so that it could not be used as an endless belt.

  A summary of these test examples is shown in Table 1. The applicability of the transfer belt was evaluated as “◯” when the desired film thickness was obtained, and “X” when the film was not obtained.

  From these test examples, if there is no inner diameter adjusting member, if the core body that has become unusable due to scratches on the core surface is used after recutting, it depends on the outer diameter of the die that has been recut from the annular body It turns out that it is necessary to change the annular body each time.

  Further, as in Test Example 3, when the outer diameter of the core and the inner diameter of the circular hole of the annular body do not match, when the entire annular body is taken out from the annular coating tank (coating liquid) and replaced, Bubbles are generated in the coating liquid. In addition, since the viscosity of the coating liquid is high, this defoaming operation takes time and continuous production becomes impossible. Furthermore, if there are several types of outer diameters of the reproduction core, it is necessary to prepare an annular body corresponding to the outer diameter, resulting in an increase in belt cost.

  On the other hand, if only the inner diameter adjusting member of the annular body is replaced according to the outer diameter of the core body used as in Test Example 2 (the coating apparatus according to the present embodiment), the desired film thickness can be obtained. It turns out that it can obtain uniformly. Moreover, since the inner diameter adjusting member can be exchanged while the annular body is floated on the coating liquid, bubbles are mixed in the coating liquid as described above, and the application stop time is shortened and the annular body is not required to be cleaned.

It is a schematic block diagram which shows the time of a stop of the coating device which concerns on embodiment of this invention. It is a schematic block diagram which shows the time of application | coating of the coating device which concerns on embodiment of this invention. It is a schematic sectional drawing which shows the annular body which concerns on embodiment of this invention. It is a disassembled perspective view which shows the annular body which concerns on embodiment of this invention.

Explanation of symbols

10 core body 11 annular coating tank 12 coating liquid 12A coating film 13 annular sealing material 20 annular body 21 annular body main body 21A opening 21B recess 21C screw hole 22 inner diameter adjusting member 22A circular hole 22B screw hole 23 arm 24 screw

Claims (4)

A core body which is an annular body which is provided with a hole having an inner diameter larger than the outer diameter of the core body to which the coating liquid is applied and is floated on the coating liquid, and which is immersed in the coating liquid stored in the coating tank. An annular body for applying the coating liquid onto the surface of the core body by vertically raising the axial direction of the coating liquid and passing it through the hole by relatively raising from the coating liquid,
The annular body includes an annular body main body and an inner diameter adjusting member that is disposed on an upper surface of the annular body main body and has a hole having a predetermined inner diameter corresponding to the outer diameter of the core body. Annulus. A coating tank for storing the coating liquid; and an annular body provided with a hole having an inner diameter larger than the outer diameter of the core body to which the coating liquid is applied and arranged to float on the coating liquid, and stored in the coating tank. The core body immersed in the coating liquid is applied by applying the coating liquid onto the surface of the core body by allowing the core body to be vertically elevated and passing through the holes while being relatively raised from the coating liquid. A device,
The said annular body is a cyclic | annular body of Claim 1, The coating device characterized by the above-mentioned. Using a coating apparatus comprising: a coating tank for storing a coating liquid; and an annular body provided with a hole having an inner diameter larger than the outer diameter of the core body to which the coating liquid is coated and arranged to float on the coating liquid, The core body immersed in the coating liquid stored in the coating tank is made to pass through the hole by being relatively raised from the coating liquid with the axial direction of the core body being vertical, and being applied to the surface of the core body. An application method for applying
The said annular body is an annular body of Claim 1, Comprising: The said internal diameter adjustment member is replaced | exchanged with the annular body main body floating according to the outer diameter of the said core body, The coating method characterized by the above-mentioned.   Using the coating apparatus according to claim 2, after coating the film forming coating liquid on the surface of the core body, drying, heat curing, firing, or all of the treatment is performed to form a film, A method for producing an endless belt, comprising removing the coating from a core.

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