JP2000190343A - Production of endless belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing an endless belt wherein a coating film formed by means of a centrifugal molding process is easily released from a coating mold. SOLUTION: In this method for producing by a centrifugal molding process, a releasable strip member 2 is arranged in advance on both end parts on the inner peripheral face of a cylindrical coating mold 1 and thereafter, a polyamic acid soln. being a precursor of a polyimide belt is poured into the inside in the axial direction of the coating mold for the strip member 2 and the coating mold 1 is rotated at high speed to form a uniform coating film by its centrifugal force. In this case, as a material for the strip member 2, such a material that is provided with an outer shape having flexibility and being arranged so as to be press-contracted on the inner peripheral face of the coating mold, is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an endless belt used in various belt devices.

[0002]

2. Description of the Related Art Conventionally, seamless endless belts have been used in various belt devices. For example, in an image forming apparatus such as an electrophotographic copying machine, a facsimile, or a printer, a transfer belt as a carrier for a toner image or a transfer material is employed.

[0003] As a method of manufacturing an endless belt adapted to such an application, conventionally, a resin as a material of the belt or a coating liquid as a precursor thereof is sprayed on the inner surface of a rotating cylindrical coating die. Or with a nozzle,
There is known a centrifugal molding method in which the coating die is rotated at a high speed, a uniform coating film is formed by the centrifugal force, and then dried, solidified, cooled, and then separated.

However, in the above-mentioned centrifugal molding method, since the film is spread on the inner surface of the above-mentioned coating die by centrifugal force, the end of the above-mentioned coating film is thinned out, and after drying and solidifying and cooling, the coating die becomes thin. Therefore, there is a problem that it is difficult to remove the coating film from the above.

Therefore, as one of the methods for solving the above-mentioned problem, there has been conventionally adopted a method of providing a band-shaped member at both ends of a coating die for stopping the flow of the coating film. An adhesive tape is generally used as the band-shaped member.

[0006]

However, when the above-mentioned pressure-sensitive adhesive tape is used as a band-like member for damping a coating solution, the tape itself is non-solvent to the coating solution even if it is non-solvent. It was found that the agent was sometimes dissolved in the coating solution solvent. When the adhesive is melted, it becomes difficult to peel off the formed coating film from the coating die. In addition, when a material having an affinity for the coating liquid is used as the material of the belt-shaped member, the coating liquid is applied on the belt-shaped member, so that both ends of the coating film are raised. It was also found that when the coating film was heated and cured in this state, a shrinkage stress was exerted, and there was a possibility that distortion or partial peeling might occur at the edge of the coating film.

[0007] In order to peel the coating film formed in the coating die from the coating die, it is desired that the end portion of the coating film be easily peeled from the coating die. However, if the end of the coating film is straight over the entire circumference, the end of the coating film is difficult to float from the coating die, and there is a problem that the peeling operation is troublesome.

The present invention has been made in view of the above problems, and a first object of the present invention is to provide a method of manufacturing an endless belt in which a coating film formed by a centrifugal molding method can be easily separated from a coating die. That is. Another object of the present invention is to provide a method for manufacturing an endless belt having no deformation at the end of the coating film.

[0009]

In order to achieve the first object, the invention according to claim 1 is a method of manufacturing an endless belt used in various belt devices, comprising: A strip-shaped member that can be peeled in advance is arranged at both ends of the surface, and thereafter, a coating liquid as a stock solution of the belt is poured into the coating member in the axial direction of the coating member of the belt-shaped member, and the coating die is rotated at a high speed, and the centrifugal force causes uniformity. In the method for producing an endless belt by centrifugal molding to form a coating film, as the belt-like member,
It is characterized by using a member that has elasticity and has an outer shape that is arranged to be pressed and shrunk on the inner peripheral surface of the coating mold.

In order to achieve the second object,
The invention according to claim 2 is a method of manufacturing an endless belt used in various belt devices, wherein strippable strip-shaped members are arranged in advance at both ends of a cylindrical coating die inner peripheral surface, and thereafter, the undiluted solution of the belt is used. The coating liquid is poured into the coating mold in the axial direction of the belt-shaped member, and the coating mold is rotated at a high speed to form a uniform coating film by centrifugal force. Is characterized by using a material having solvent repellency to the coating liquid.

According to a third aspect of the present invention, in the method for manufacturing an endless belt according to the second aspect, the band-shaped member has an elasticity and an outer shape arranged to be pressed and shrunk on the inner peripheral surface of the coating mold. Characterized by using a member having

According to a fourth aspect of the present invention, in the method for manufacturing an endless belt according to any one of the first to third aspects, a material that does not deform at the heating and curing temperature of the coating liquid is used as the material of the belt-shaped member. is there.

According to a fifth aspect of the present invention, in the method of manufacturing an endless belt according to any one of the first to fourth aspects, the belt-like member is made of PT.
FE is used.

According to a sixth aspect of the present invention, in the method for manufacturing an endless belt according to any one of the first to fifth aspects, a core rotating body is disposed inside the coating mold so as to come into contact with the belt-shaped member. By rotating, the belt-shaped member is brought into close contact with the coating die.

According to a seventh aspect of the present invention, in the method for manufacturing an endless belt according to any one of the first to fifth aspects, a flexible or elastic member is placed on the band-shaped member disposed inside the coating mold, and the flexible or elastic member is provided. The band member is brought into close contact with the coating die.

In order to achieve the first object, an invention according to claim 8 is a method of manufacturing an endless belt used in various belt devices, wherein the method comprises the steps of: A possible band-shaped member is arranged, and thereafter, a coating liquid as a stock solution of the belt is poured into the inside of the band-shaped member in the axial direction of the coating die, the coating die is rotated at high speed, and a uniform coating film is formed by the centrifugal force. In the method for producing an endless belt by a centrifugal molding method, the band-shaped member is controlled and prevented from permeating the coating liquid between the band-shaped member and the inner peripheral surface of the coating die at least at the time of high-speed rotation of the coating die. It is characterized by being arranged in close contact with the coating die.

Here, the close contact arrangement means to adhere closely by arrangement, that is, to adhere the belt-like member to the inner peripheral surface of the coating mold without using an adhesive.

According to a ninth aspect of the present invention, there is provided the method of claim 1, 2, 3,
In the method for producing an endless belt of 4, 5, 6, 7 or 8, at least one end of the coating film formed on the inner peripheral surface of the coating die in the axial direction of the coating die protrudes in the axial direction and the coating is performed. It has a convex portion which can be removed after peeling the film from the coating die.

According to a tenth aspect of the present invention, in the method for manufacturing an endless belt according to the ninth aspect, a recess is formed at an inner end of the belt-shaped member in the axial direction of the coating die.

According to an eleventh aspect of the present invention, in the method for manufacturing an endless belt according to the ninth or tenth aspect, the convex portion of the coating film is peeled off from the coating die to peel the coating film from the coating die. It is a feature.

According to a twelfth aspect of the present invention, in the method of manufacturing an endless belt according to the eleventh aspect, the convex portion is peeled off from the coating die by vacuum decompression to peel the coating film from the coating die. Things.

[0022]

[Embodiment 1] An embodiment of a method of manufacturing an endless belt according to the present invention will be described. In the present embodiment, a polyimide having excellent strength and heat resistance is used as the material of the endless belt, and a polyamic acid solution as a precursor of the polyimide is stretched by a centrifugal force into a cylindrical coating mold to form a cylindrical shape. It utilizes a centrifugal forming method for obtaining a polyamic acid film. The polyamic acid solution has a property of being converted into polyimide by imide ring closure by heat or a catalyst and being dissolved by a specific solvent. In the present embodiment, DMAC (N, N-
A polyamic acid solution prepared by dispersing carbon black as a conductive agent in dimethylacetamide (30% by weight) was used.

FIG. 1 is an axial sectional view of a cylindrical coating mold 1 used in a centrifugal molding method. The coating die 1 used was a die. At both ends of the inner peripheral surface of the coating die 1, belt-shaped members 2 for stopping the flow of the polyamic acid solution 3 due to centrifugal force are arranged in advance. FIG. 2 shows a perspective view of the coating die 1 in this state. As the material of the belt-shaped member 2,
A material that is not eroded by the polyamic acid solution 3, that has an outer shape that fits snugly on the inner peripheral surface of the coating mold 1, and that can be easily removed after heating and solidifying the polyamic acid solution 3. select. The belt-shaped member 2 has heat resistance at about 150 ° C., which is the drying temperature of the polyamide solution 3, or has a heat-curing temperature of 30 ° C.
It is desired that it has heat resistance at 0 ° C. and does not cause deformation or shrinkage. In the present embodiment, a porous PTFE tape having elasticity and having a solvent repellency to the above-mentioned DMAC which is a solvent of the polyamic acid solution 3 is used as a material satisfying these.

This PTFE tape (width 10 mm, thickness 2
mm) is cut slightly larger than the inner diameter of the coating mold 1,
Utilizing the elasticity of the PTFE tape itself, it is fitted so as to be pushed into the inner peripheral surface of the coating die 1. Thereby, the coating die 1
Can be attached to the inner peripheral surface without using an adhesive, so that the problem that the adhesive dissolves in the coating solution solvent can be avoided. In addition, the following method can also be adopted in order to ensure that the PTFE tape is in close contact with the coating die 1. As shown in FIG. 3, after setting the PTFE tape at both ends of the coating die 1, the PTFE tape at both ends of the coating die 1 is set.
A metal rod 5 which is a core cylindrical body is placed inside the coating die 1 so as to hang on the E tape, and the coating die 1 is rotated. This coating type 1
The metal rod 5 rotates so as to roll at the bottom of the coating die 1 with the rotation of the coating die 1. At this time, the metal rod 5 uniformly contacts the entire area of the PTFE tape, and the PTFE tape is pressed onto the inner peripheral surface of the coating die 1. As a result, it can be brought into close contact without lifting. Therefore, leakage of the polyamic acid solution 3 can be reliably prevented.

In the above state, an endless polyimide belt 19 is formed by a centrifugal molding method. Specifically, the polyamic acid solution 3 is injected into the coating die 1 and the coating die 1 is
When rotated at a high speed of 0 rpm, the polyamic acid solution 3 is cast into the coating mold 1 by centrifugal force. At this time, the polyamic acid solution 3 spreads as a uniform polyamic acid film toward both ends of the inner peripheral surface of the coating die 1, and FIG.
As shown by, the PTFE tape as the band-shaped member 2 having solvent repellency to the polyamic acid solution 3 is repelled and the end is rounded. Therefore, unlike the case where a material having an affinity for the coating liquid is used as the material of the belt-shaped member 2, the material is not raised and applied on the belt-shaped member. The shape deformation of the end of the acid film can be prevented (see FIG. 5). Further, unlike the case where the belt-shaped member 2 is not used, the polyamic acid film does not gradually become thin at the end portion, so that the film or the belt after heating and solidification of the film is easily separated (see FIG. 6). ).

Next, after the solvent of the polyamic acid film is dried and solidified, the film is further heated to 300 ° C. to cure the film. As a result, the polyamide acid film is imide-closed to form an endless polyimide belt 19. After that, the coating mold 1 was cooled, and the PTFE tape was first removed.
The tape itself could be easily removed due to its elasticity. Furthermore, even when the polyimide belt 19 is peeled off, the adhesive is not melted as in the case of using an adhesive tape as the belt-shaped member 2, and the belt end is rounded as described above. It could be easily peeled off from the coating die 1.

[Embodiment 2] Next, another embodiment will be described with reference to FIG. In the first embodiment, porous PTFE having a thickness of 2 mm is used as the belt-shaped member 2 for stopping the flow of the polyamic acid solution 3 due to centrifugal force.
Although a tape is used, in the present embodiment, a 4 mm thick porous PTFE tape is used, and an endless polyimide belt 19 is similarly formed by a centrifugal molding method.

Similar to the first embodiment, when the PTFE tape is arranged at both ends of the inner peripheral surface of the coating die 1 so as to be compressed and contracted by the elasticity of the tape itself, the thickness of the tape itself causes the coating PTFE tape to shrink. And a gap was created between them. Then, in this state, as shown in FIG. 7, an elastic PTFE plate 4 having a thickness of 2 mm is rolled and inserted into the coating mold 1, and this PTFE is
By the spring action of the plate 4, the PTFE tape as the band-shaped member 2 was pressed against the coating die 1, and the PTFE tape was brought into close contact with the coating die 1. FIG. 8 shows a circumferential sectional view of the coating die 1 in this state. Thereafter, when the PTFE plate 4 was removed from the coating mold 1, it could be easily removed due to its elasticity. In the present embodiment, as a material for pressing the PTFE tape against the coating mold 1,
Although the FE plate 4 is used, any material having flexibility or elasticity may be used, and the material is not limited to this.

In the above state, the endless polyimide belt 19 is formed by the centrifugal molding method as in the first embodiment. At this time, it was confirmed that there was no leakage of the polyamic acid solution 3 flowing out from between the PTFE tape and the coating mold 1. Further, similarly to the first embodiment, the polyamic acid solution 3 was repelled by the PTFE tape, the ends were rounded, and the polyamic acid film did not gradually become thin at the ends.

Next, after the solvent of the polyamic acid film was dried and solidified, an imide ring closure reaction was performed at 300 ° C., and the film was cured by further heating. Thereafter, the coating die 1 was cooled, and the PTFE tape was first removed. However, the PTFE tape could be easily removed due to the elasticity of the tape itself. Furthermore, when peeling off the molded polyimide belt 19,
Since the adhesive is not melted as in the case where an adhesive tape is used as the belt-shaped member 2 and the belt end is rounded as described above, the belt can be easily peeled off from the coating mold 1. Was.

As described above, in the first and second embodiments, the PTFE tape as the belt-shaped member 2 is arranged so as to be pressed and shrunk on the inner peripheral surface of the coating mold 1 due to the elasticity of the tape itself. Can be pasted on. Therefore, when the pressure-sensitive adhesive tape is used, it is possible to prevent the problem that the pressure-sensitive adhesive is dissolved in the polyamic acid solution 3 and it is difficult to remove the pressure-sensitive adhesive from the coating mold 1. Can be peeled off. In addition, since the gap between the coating mold 1 and the coating mold 1 is hardly generated by being arranged to be compressed, it is possible to prevent the polyamic acid solution 3 from leaking. In addition, PTF
Due to the solvent repellency of the E tape, when the polyamic acid solution 3 flows and reaches the PTFE tape, the PTFE tape repels the polyamic acid solution 3.
Will not get on the tape. Therefore, the end portion of the polyamic acid film is not formed to be raised and the shape of the end portion of the polyamic acid film is prevented from being deformed by the shrinkage stress at the time of heat curing, so that the shape of the endless belt finally obtained is also good. .

Further, the PTFE tape is a material which does not deform at a heat curing temperature of 300 ° C. of the polyamic acid film, and it is not necessary to remove the belt-shaped member 2 before the heat curing, so that it has an excellent effect of improving workability. .

In the first and second embodiments, since the end of the belt-shaped member 2 on the side in contact with the endless belt is formed linearly, a belt having a uniform axial width can be obtained. Since the end of the endless belt thus obtained is straight, there was no clue for lifting the end of the endless belt from the coating mold. Therefore, in order to make the peeling easier, it is conceivable to provide a clue at the time of forming the endless belt. The embodiment will be described below. [Embodiment 3] FIG. 9 shows a band-like member 2 according to Embodiment 3.
The front view which shows the end part shape by the side which damps the polyamic-acid solution of FIG. FIG. 10 is a perspective view of the band-shaped member 2. In the present embodiment, as shown in FIG. 9, a V-shaped notch 2 a as a concave portion is provided on the inside of the band-shaped member 2 in the axial direction of the coating die. As shown in FIG. 10, a plurality of the notches 2 a are provided in the entire circumferential direction of the belt-shaped member 2. Such a band-shaped member 2 is provided at one end of the inner peripheral surface of the coating die, and at the other end, the band-shaped member 2 having no notch 2a is formed so that no gap is formed between each of the band-shaped members 2 and the coating die. Closely arranged.

In the above state, an endless polyimide belt 19 is formed by a centrifugal molding method. Specifically, using a polyamic acid solution 3 obtained by diluting a polyimide precursor solution (manufactured by Toray Co., Ltd .: Treeneth # 3000) to 30% with DMAC as a solvent, endless molding was performed by centrifugal molding in the same manner as in Embodiments 1 and 2. Is formed. At this time, the polyamic acid solution spreads as a uniform polyamic acid film toward both ends of the inner peripheral surface of the coating die by the high-speed rotation of the coating die, and enters into the notch 2a at one end.

Next, after the solvent of the polyamic acid film is dried and solidified, the film is further heated to 300 ° C. to cure the film. As a result, the polyamide acid film is imide-closed to form an endless polyimide belt 19. Thereafter, the coating die 1 was cooled, and first, the belt-shaped member 2 was removed. FIG.
Is a perspective view of the polyimide belt 19 formed at this time. As shown in this figure, one end of the belt is blocked by the band-shaped member 2 and has a plurality of convex portions 3a protruding in a mountain shape.
It has a shape having. Note that the shape of the notch 2a provided in the belt-shaped member 2 is not limited to the V-shape. In the present embodiment, in addition to the V-shape, a semicircular shape shown in FIG. 12 or a trapezoidal shape shown in FIG. 13 is also used, and the polyimide belt 19 having a semicircular or trapezoidal convex portion at one end of the film is also formed. Was.

Next, a method of peeling the polyimide belt 19 from the coating mold will be described. FIG. 14 shows the third embodiment.
5 is a partial cross-sectional view of the peeling device 6 according to FIG. The peeling device 6 has a reduced-pressure suction mechanism for peeling the polyimide belt 19 from the inner peripheral surface of the coating die by suction. The peeling device 6 includes a suction jig and a vacuum pump. The suction jig includes the top plates 6a and 6b and the suction cylinder 6c.
The two top plates 6a are formed in a disk shape having substantially the same diameter as the inner peripheral surface of the polyimide belt 19, and are supported at intervals. These top plates 6a, 6b
The outer peripheral portion, which is a portion that comes into contact with the belt surface when inserted into the inner surface of the polyimide belt 19, is formed of an elastic body. The top plate 6b is provided with a hole for inserting a suction tube in the center thereof, and one end of the suction tube 6c is inserted into the hole, so that the gap between the top plates 6a and 6b and the inside of the suction tube 6c are formed. And form a single suction space 6d communicating with the suction space 6d. A vacuum pump (not shown) for sucking air inside the suction space 6d is provided at the other end of the suction tube 6c.

A method of peeling the polyimide belt 19 using the peeling device 6 having the above structure will be described. First, the suction jig 6c side of the suction jig is inserted into the coating mold, and the belt is moved until the end of the belt is located between the top plate 6a and the top plate 6b.
Next, the air inside the suction space 6d is sucked by the vacuum pump. Suction space 6 as air is sucked
The inside of d is depressurized, and the end of the polyimide belt 19 exposed in the space 6d is peeled off from the inner wall of the coating die in the direction of arrow A in the figure. While the air is being suctioned, pull the polyimide belt 19 in the direction of arrow B in the drawing jig.
Is sequentially peeled from the inner wall of the coating mold.

Here, the once cured polyimide film is
Even if the inner peripheral surface of the coating type is a fluororesin film having release properties,
It is difficult to peel off only by the tension due to suction. In other words, a vacuum space 6d is formed between the inner peripheral surface of the coating mold and the film by pulling the adhered surface as it is in the vertical direction. This is because the pressing force is applied to the true adhesion between the coating die and the film, resulting in a strong adhesion. However, as long as the end of the polyimide belt 19 film can be peeled off, air flows from there, and the pressing force due to the atmospheric pressure disappears, so that the film is adhered only by the true adhesion between the coating mold and the film. . In the third embodiment, the protrusion 3a is formed at the end of the polyimide belt 19 in the axial direction at the side where the peeling device 6 first peels off. The protrusion 3a facilitates the lifting of the end from the coating die by suction as compared with the case where the protrusion is a flat end.

Table 1 shows the shape of the convex portion 3a formed at the end of the polyimide belt 19 in the axial direction and the result of the peeling and releasing condition when peeling was performed using the peeling device 6 described above.
This is a comparison with the state of peeling and releasing of the belt when no belt is formed.

[Table 1] From the results shown in Table 1 above, although the polyimide belt 19 having the convex portions 3a had a difference in peeling and releasability depending on the shape of the convex portions, none of the polyimide belts 19 was coated as compared with those having no convex portions. Peeling and demolding from the mold were successfully performed. After peeling,
By cutting off the convex portions, the polyimide belt 19 can be shaped into a cylindrical shape, and can be used as an endless belt.

According to the third embodiment, when the polyimide belt 19 is peeled off from the coating mold, the polyimide belt 19 can be automatically peeled off by using the peeling device 6 by suction. here,
By forming a convex portion at the end of the polyimide belt 19 and starting peeling from this portion, peeling of the remaining portion becomes easy. Therefore, when it is difficult to peel off the edge, a knife edge or the like is manually inserted between the belt and the coating die from the edge of the belt, and the belt edge is lifted with great care. No work is required, and the peeling operation becomes easy.

Next, an example will be described in which the endless polyimide belt 19 obtained in the first to third embodiments is used as an intermediate transfer belt of an electrophotographic copying machine (Ricoh full-color copying machine pretail). FIG. 9 is a schematic configuration diagram of a copying machine according to this experimental example. First, the configuration and operation of the copying machine will be briefly described. In FIG. 15, an electrostatic latent image is formed on the photoconductor 9 by a known process, and then development of each color is repeated by the developing units 14, 15, 16, and 17, and each color image (toner) is formed on the photoconductor 9. Images) are sequentially formed. The toner images of each color are sequentially superimposed and transferred to the same position on the intermediate transfer belt 19 by a predetermined bias voltage applied to the transfer bias roller 20a for each single color. Are collectively transferred to a transfer material such as After the transfer, the transfer material is sent to a fixing device 28 where the toner image is fixed to complete a full-color image.

The intermediate transfer belt 19 includes a belt drive roller 21, a transfer bias roller 20a, and a ground roller 2.
0b and a group of driven rollers, and is driven and controlled by a drive motor (not shown). As described above, since the intermediate transfer belt 19 has tapes integrally formed as stoppers at both ends of the inner peripheral surface of the belt, it is possible to prevent a displacement on the roller group when the belt is driven. it can.

Then, when image formation was actually performed using the two endless belts obtained in the first and second embodiments in the above-described copying machine, any of the above-mentioned copying machines did not produce any repetitive output of 400,000 sheets. No abnormalities occurred.

[0044]

According to the first aspect of the present invention, since the belt-shaped member is arranged to be pressed and shrunk on the inner peripheral surface of the coating mold due to the elasticity of the member itself, it can be attached without using an adhesive. . Therefore, it is possible to avoid a problem that the pressure-sensitive adhesive is dissolved in the coating liquid when using the pressure-sensitive adhesive tape, so that the coating film can be easily peeled from the coating mold. In addition, by being arranged to shrink,
Since a gap with the coating mold is less likely to occur, leakage of the coating liquid can be prevented.

According to the second aspect of the present invention, when the coating liquid flows and reaches the belt-like member due to the solvent repellency of the belt-like member, the belt-like member repels the coating liquid. It does not get on the member. Therefore, since the end portion of the coating film is not formed so as to be raised, it is possible to obtain a good endless belt in which the end portion of the coating film is not deformed due to contraction stress at the time of heat curing of the coating film.

According to the third or fifth aspect of the present invention, since the belt-shaped member has both solvent repellency and elasticity, the coating film can be easily peeled off from the coating mold and the shape of the edge of the coating film can be easily reduced. There is an excellent effect that a good endless belt without deformation can be obtained.

According to the fourth or fifth aspect of the present invention, since the coating film is not deformed even when it is cured by heating, it is not necessary to remove the belt-shaped member before curing by heating. Therefore, there is an excellent effect that workability is improved.

According to the sixth aspect of the present invention, since the core rotating body makes uniform contact with the entire area of the belt-shaped member, the core rotating body can be stuck to the coating mold without any gap, so that leakage of the coating liquid can be reliably prevented. Has an effect.

According to the seventh aspect of the present invention, since the flexible or elastic member presses the band-shaped member against the coating mold, the band-shaped member can be prevented from floating and can be stuck to the coating mold without any gap. There is an excellent effect that leakage of the coating liquid can be reliably prevented. Moreover, since it has flexibility or elasticity, it can be easily taken out of the coating mold.

According to the eighth aspect of the present invention, the band-shaped member is brought into close contact with the inner peripheral surface of the coating die by arrangement, so that the band-shaped member can be attached without using an adhesive. Therefore, it is possible to avoid the problem that the pressure-sensitive adhesive is dissolved in the above-mentioned coating solution when using the pressure-sensitive adhesive tape, and thus the coating film can be easily peeled from the coating mold. In addition, the close contact arrangement prevents a gap from the coating die from being generated, so that leakage of the coating liquid can be prevented.

According to the ninth aspect of the present invention, since the convex portion formed at the end of the coating film formed on the inner peripheral surface of the coating mold has good releasability from the coating mold, the convex portion is used. Thereby, the coating film can be easily peeled from the coating mold. This facilitates peeling using an apparatus and facilitates automation of peeling of the coating film. In addition, by removing the protrusions at the end portions of the coating film after the coating film is peeled off, it is possible to easily obtain a good endless belt having uniform end portions.

According to the tenth aspect of the present invention, when the application liquid blocked by the band-like member is blocked by the band-like member, it enters into the concave portion of the band-like member and forms a coating film as it is, so that the coating liquid is applied to the edge of the coating film. A protrusion protruding in the mold axis direction can be easily formed.

According to the eleventh aspect of the present invention, when the coating film is peeled from the coating mold, the remaining portion can be sequentially peeled from the coating mold by first peeling off the projection at the end of the coating film from the coating mold. The coating film can be easily peeled off. This facilitates peeling using an apparatus, and facilitates automation of peeling such as peeling of a coating film by an apparatus.

According to the twelfth aspect of the present invention, the convex portion at the end of the coating film can be easily peeled off from the coating mold by vacuum decompression, and the coating film can be easily peeled off. This makes it possible to automate the peeling of the coating film by using a peeling device using vacuum decompression.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram for explaining a method of manufacturing an endless belt by a centrifugal molding method according to a first embodiment.

FIG. 2 is a perspective view of a coating type used in the centrifugal forming method.

FIG. 3 is an explanatory view for explaining a method of bringing a belt-shaped member into close contact with the coating die.

FIG. 4 is an enlarged view of one end of a coating film formed inside the coating die.

FIG. 5 is an explanatory view for explaining a problem of a conventional endless belt manufacturing method.

FIG. 6 is an explanatory view for explaining another problem of the conventional endless belt manufacturing method.

FIG. 7 is an explanatory diagram for explaining a method of manufacturing an endless belt by a centrifugal molding method according to a second embodiment.

FIG. 8 is a circumferential sectional view of a coating type used in the centrifugal forming method.

FIG. 9 is an exemplary front view showing an end shape of the belt-shaped member according to the third embodiment;

FIG. 10 is a perspective view of the band-shaped member.

FIG. 11 is a perspective view of a polyimide belt formed in a coating mold according to a third embodiment.

FIG. 12 is a front view showing another end shape of the belt-shaped member.

FIG. 13 is a front view showing another end shape of the belt-shaped member.

FIG. 14 is a partial cross-sectional view of the peeling device according to the third embodiment.

FIG. 15 is a schematic configuration diagram of a copying machine to which the endless belt according to the first to third embodiments can be applied.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 coating type 2 band-shaped member 2 a notch 3 polyamic acid solution 4 PTFE plate 5 metal rod 6 peeling device 6 a, 6 b top plate 6 c suction tube 6 d suction space 9 photoconductor 14, 15, 16, 17 developing unit 19 intermediate transfer belt (Polyimide belt)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) B29K 77:00 B29L 29:00

Claims (12)

[Claims] 1. A method for producing an endless belt used in various belt devices, comprising a step of arranging strippable members in advance at both ends of an inner peripheral surface of a cylindrical coating die, and thereafter, as a stock solution of the belt. The coating liquid is poured into the coating member axially inward of the belt-shaped member, the coating die is rotated at a high speed, and a method of manufacturing an endless belt by a centrifugal molding method of forming a uniform coating film by the centrifugal force, wherein the belt-shaped member is A method for producing an endless belt, comprising using a member which has elasticity and has an outer shape arranged to be pressed and shrunk on the inner peripheral surface of the coating mold. 2. A method for producing an endless belt used in various belt devices, comprising a step of disposing strip-shaped members in advance at both ends of a cylindrical coating die inner peripheral surface, and thereafter forming a belt-shaped undiluted solution. A method of manufacturing an endless belt by a centrifugal molding method in which a coating liquid is poured into an axial direction of a coating die of the belt-shaped member, the coating die is rotated at a high speed, and a uniform coating film is formed by the centrifugal force. Wherein a material having solvent repellency to the coating liquid is used. 3. The method for manufacturing an endless belt according to claim 2, wherein the belt-shaped member is a member having elasticity and having an outer shape arranged to be pressed and shrunk on the inner peripheral surface of the coating mold. A method for producing an endless belt, which is used. 4. The method for producing an endless belt according to claim 1, wherein a material that does not deform at the heating and curing temperature of the coating liquid is used as the material of the belt-shaped member. 5. A method for manufacturing an endless belt according to claim 1, wherein PTFE is used as said belt-shaped member. 6. The method for manufacturing an endless belt according to claim 1, wherein a core rotating body is disposed inside the coating mold so as to contact the belt-shaped member, and the core rotating body is rotated.
A method for producing an endless belt, comprising bringing the belt-shaped member into close contact with the coating die. 7. The method for manufacturing an endless belt according to claim 1, wherein a flexible or elastic member is placed on the band-shaped member disposed inside the coating mold, and the band-shaped member is covered by the flexibility or elasticity. A method for producing an endless belt, wherein the method is brought into close contact with the coating die. 8. A method for producing an endless belt used in various belt devices, comprising a step of arranging strippable members in advance at both ends of a cylindrical coating die inner peripheral surface, and thereafter, as a stock solution of the belt. The method for manufacturing an endless belt by a centrifugal molding method in which a coating liquid is poured into the coating member in the axial direction of the coating member and the coating die is rotated at a high speed and a uniform coating film is formed by the centrifugal force. Endless belt manufacturing characterized in that the coating die is disposed in close contact with the coating die so as to suppress and prevent the penetration of the coating liquid between the belt-shaped member and the inner peripheral surface of the coating die at least during high-speed rotation of the coating die. Method. 9. The method of claim 1, 2, 3, 4, 5, 6, 7, or 8.
In the method for producing an endless belt, at least at one end of the coating film formed on the inner peripheral surface of the coating die in the axial direction of the coating die, after projecting in the axial direction and after peeling the coating film from the coating die. A method for manufacturing an endless belt having a removable convex portion. 10. The method for producing an endless belt according to claim 9, wherein a recess is formed at an inner end of the belt-shaped member in the axial direction of the coating die. 11. The method for producing an endless belt according to claim 9, wherein the coating film is peeled from the coating mold by peeling off the projections of the coating film from the coating mold. Manufacturing method. 12. The method for producing an endless belt according to claim 11, wherein said convex portion is peeled off from said coating die by vacuum decompression, whereby said coating film is released from said coating die. .