JP5611720B2 - Seamless belt manufacturing apparatus and seamless belt manufacturing method - Google Patents

Description

  The present invention uses a seamless belt manufacturing apparatus that rotates the cylindrical mold in which a resin solution is developed on the inner surface of the cylindrical mold to make the coating film uniform, and the seamless belt manufacturing apparatus. A seamless belt comprising a step of rotating a cylindrical mold in which a resin solution is spread on the inner surface of the cylindrical mold to uniformize the coating film, and a step of heat-curing the coating film on the inner surface of the cylindrical mold. It relates to the manufacturing method.

  Transfer transfer belts, intermediate transfer belts, transfer fixing belts, and photoreceptor belts used in image forming apparatuses such as electrophotographic copying machines, printers, facsimiles, and multi-function machines are required to have high speed and high image quality. These functional belts are seamless belts. The seamless belt is generally manufactured, for example, by spreading a resin solution on the inner surface of a cylindrical mold and then leveling the cylindrical mold while rotating at a low speed to form a dry film.

  In addition, as a seamless belt manufacturing apparatus, a mechanism (centrifugal molding mechanism) is known in which a resin solution is spread on the inner surface of a cylindrical mold, and then one end of the mold is cantilevered by a rotating holder and rotated. . Further, as another manufacturing apparatus, a plurality of drives for rotating a cylindrical mold by providing a pair of lids that are detachably fitted to both ends of the cylindrical mold on the outer periphery of the mold. A mechanism having a roller and rotating a drive roller to rotate a lid and a cylindrical mold that are in contact with the roller, or simply contacting the outer peripheral surface of the cylindrical mold with a plurality of drive rollers to form a cylindrical mold There is known a mechanism for rotating the lens (see Patent Documents 1 and 2).

Japanese Patent No. 3922840 JP2007-1262

  However, the seamless belt manufacturing apparatus and other manufacturing apparatuses of Patent Document 1 have the following problems. In order to improve the accuracy of centrifugal molding, the accuracy of the outer peripheral surface is required in addition to the accuracy of the inner peripheral surface of the mold. Further, there is a problem that chattering occurs when the mold rotates at high speed of 1000 rpm or more due to the accuracy of the outer peripheral surface, resulting in variations in the thickness accuracy of the seamless belt and dust generation.

  For this reason, a resin solution that cannot be rotated at a high speed of 1000 rpm or more and developed by centrifugal force has to have a reduced viscosity, and the amount of solvent used has increased.

  In addition, when the resin solution viscosity is low, when the heating is performed together with the centrifugal molding, the solution viscosity is lowered by the heating, and the resin solution is likely to flow down without being in close contact with the inner peripheral surface of the mold. A drying process in which a constant centrifugal force is continuously applied until the remaining amount decreases is also required.

  Further, in the manufacturing apparatus of Patent Document 1, when the outer surface of the mold is brought into contact with and supported by the drive roller, the vertical movement of the mold is caused by the dimensional change of the mold due to heating, the dimensional wear of the used sprocket and the drive roller, etc. A minute slip will be caused. Due to this, dust generation due to variations in thickness accuracy and contact between the outer peripheral surface of the mold and the driving roller is likely to occur, and the yield rate is likely to decrease.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a seamless belt manufacturing apparatus and a seamless belt manufacturing method capable of suppressing variations in thickness accuracy of the seamless belt.

  In order to solve the above problems, as a result of intensive research, it is effective to develop a high-viscosity resin solution in a mold and perform leveling (homogenization) in a short time with high-speed rotation. It was found that a method of drying at a lower speed than that was effective when the film was heat-cured.

The present invention is a seamless belt manufacturing apparatus for rotating a cylindrical mold in which a resin solution is spread on the inner surface of a cylindrical mold and uniformizing a coating film,
A pair of fixing means for fixing both ends of the cylindrical mold, and a pair of fixing means arranged on opposite sides on the same core as the cylindrical mold;
Advancing / retreating drive means for moving the advancing / retreating in the axial direction of the cylindrical mold so as to fix the fixing means to the end of the cylindrical mold;
Rotation driving means for rotating the fixing means around its axis,
The cylindrical mold is rotated by fixing both ends of the cylindrical mold with the pair of fixing means, rotating the fixing means with a rotation driving means, and rotating the cylindrical mold. The configuration is as follows.

  The “pair of opposing fixing means” is exemplified by a pair of opposing chucking means, for example. As a chuck means, for example, a conical cone chuck that can be chucked by a pair of opposed chucks on the same core, a trapezoid cone cone chuck, a cone cone having an inverted inner cone shape or a trapezoidal inner surface, and a cylindrical mold end grip Alternatively, a claw-like chuck that is sandwiched and fixed may be used. Examples of the method for fixing the pair of various cone chucks include a method in which both ends of a cylindrical mold are sandwiched and fixed at a high pressure.

  One of the pair of fixing means is rotated around its axis by the rotational action transmitted from the rotation driving means, and the other fixing means is configured to be rotatable around the axis. The advancing / retreating drive means is arranged so that the other fixing means is fixed to the cylindrical mold end with respect to the cylindrical mold end different from the end fixed by one fixing means. It can be configured to move in the axial direction so as to be able to advance and retract. Alternatively, the advancing / retreating driving means can be installed for each of the pair of fixing means, and each of the advancing / retreating driving means can be configured to move the respective fixing means to fix the cylindrical mold end.

  With this configuration, the cylindrical mold does not run out and can be rotated easily at high speed. Moreover, even if a highly viscous resin solution is used, variation in the thickness accuracy of the seamless belt manufactured can be suppressed. The conventional manufacturing apparatus of Patent Document 1 cannot level (homogenize) a high-viscosity resin solution at high speed and in a short time, but the present invention can do so. That is, according to the present invention, it is possible to develop a high viscosity resin solution and level it in a short time with high-speed rotation, and a high-precision tube having uniform thickness accuracy and surface accuracy without waviness and streaks. The body seamless belt can be easily obtained. When such a belt is used as a functional belt such as a fixing belt, a transfer belt, an intermediate transfer belt, a conveyance belt, and a photosensitive belt of an electrophotographic image forming apparatus and a base material thereof, it has excellent dimensional accuracy. Therefore, it is useful as a functional belt that satisfies the required functions such as fixability, transferability, and transportability.

  As one embodiment of the present invention, there is a configuration in which the cylindrical mold and the pair of fixing means have lifting means for adjusting the arrangement of the opposing pair on the same core. The lifting / lowering means includes a lifting / lowering base for placing the cylindrical mold and a lifting / lowering driving means for moving the lifting / lowering base up and down. This lifting platform is preferably installed parallel (horizontal) to its installation surface (horizontal), and is maintained horizontal at any lifting position. In the present invention, “horizontal” is not limited to the horizontal in the strict sense, and may be inclined from the horizontal axis as long as there is no problem in the production of the seamless belt. If the lifting platform is horizontal, the cylindrical mold placed on it is also kept horizontal. And it is preferable that the fixing means and the cylindrical mold are concentric (the central axes thereof coincide), and the cylindrical mold after being fixed by the fixing means is also kept horizontal.

  As another embodiment, the elevating means moves the cylindrical mold placed on the elevating platform so that it is concentric with the fixing means, and then fixes one end of the cylindrical mold to the other. The lifting platform can be configured to move concentrically so as to be fixed to the means.

  As one embodiment of the present invention, the cylindrical mold and the pair of fixing means control the elevating means so that they are arranged in a confronting pair on the same core, and the fixing means is arranged in the axial direction of the cylindrical mold. There is a configuration having a control means for controlling the advancing / retreating drive means to move and fix the fixing means to the end of the cylindrical mold.

According to this configuration, it is not necessary to manually operate the elevating means and the advancing / retreating drive means, and after the cylindrical mold is installed on the elevating table of the elevating means, the elevating operation and the advancing / retreating operation of the fixing means can be automated. Further, the control means controls the rotation driving means, it can be configured to automate the rotation control of the solid Teite stage.

  As one embodiment of the above control means, the control means includes a cylindrical mold installed at a predetermined position on the lifting platform of the lifting means and a fixing means fixed to the end of the cylindrical mold. It has a judgment part which judges whether it is fixedly arranged on the core based on the advance movement distance of the fixing means, and the judgment part is fixedly arranged on the same core with the cylindrical mold and the fixing means. If it is determined that the rotation means is in rotation, the rotation driving means can start the rotation of the fixing means.

According to this configuration, the rotation of the fixing unit by the rotation driving unit can be started after determining whether or not the cylindrical mold and the fixing unit are fixed on the same core. If they are rotated when they are not concentric, the seamless belt cannot be uniformly spread, and the film thickness variation is large and the defect rate is high, which is not preferable. Furthermore, the control means has a configuration including means (warning lamp, sound, etc.) for notifying the warning when they are not concentric. The control means may, if they if fixed on the core, by controlling the rotation drive means, can be configured to automate the rotation control of the solid Teite stage.

  In the present invention, the resin solution is a solution containing a polyamic acid solution as a main component, the resin solution has a viscosity of 50 to 500 Pa · s, and the rotational speed of the cylindrical mold during the uniform coating is determined. There exists a structure which has a control means which controls a rotation drive means so that it may become the range of 1000 rpm-4000 rpm.

  With this configuration, even if the resin solution viscosity is a high viscosity of 50 to 500 Pa · s, the coating film can be made uniform in a short time by high-speed rotation in the range of 1000 rpm to 4000 rpm. The homogenization time of the coating film is set according to the resin solution viscosity, the number of rotations, the cylindrical mold size, and the coating amount of the resin solution, and examples thereof include a range of 30 seconds to 1 hour.

  Further, the seamless belt manufacturing apparatus is exemplified by a configuration in which the outer peripheral surface of the cylindrical mold is heated by a heating unit and the coating film is heat-cured in the process of homogenizing the developed resin solution. Moreover, the structure which rotates a cylindrical metal mold in the case of the heat-hardening process of the coating film after the equalization process of the expand | deployed resin solution is illustrated. As one embodiment of the control means for controlling the rotation driving means, the rotational speed of the cylindrical mold when the coating film is heat-cured is the rotational speed of the cylindrical mold when the coating film is uniformized. There is a configuration in which the rotation driving means is controlled so as to be slower. As a result, a high viscosity resin solution can be developed and uniformized in a short time with high speed rotation, and the coating film can be heated and cured at a lower speed than that, so that the film thickness is uniform without waviness and streaks, A seamless belt of a high-precision tubular body having surface accuracy can be suitably manufactured.

In addition, the manufacturing method of the seamless belt of the other invention,
Using the seamless belt manufacturing apparatus, the step of rotating the cylindrical mold in which the resin solution is spread on the inner surface of the cylindrical mold to make the coating film uniform, and the coating of the inner surface of the cylindrical mold A process for producing a seamless belt comprising heat-curing the film,
The cylindrical mold is fixed by fixing means so that both ends of the cylindrical mold are concentric with the cylindrical mold, and the fixing means is rotated around its axis, whereby the cylindrical mold is It is the structure characterized by rotating.

  With this configuration, the cylindrical mold does not run out and can be rotated easily at high speed. Moreover, even if a highly viscous resin solution is used, variation in the thickness accuracy of the seamless belt manufactured can be suppressed. That is, according to the present invention, it is possible to develop a high viscosity resin solution and level it in a short time with high-speed rotation, and a high-precision tube having uniform thickness accuracy and surface accuracy without waviness and streaks. The body seamless belt can be easily obtained.

  Further, as one embodiment of the above manufacturing method, the cylindrical mold and the fixing means based on the moving distance from the origin position to the respective fixed ends of the cylindrical mold. Is configured to be able to start rotation of the fixing means.

  Moreover, as one embodiment of the above production method, the resin solution is a solution containing a polyamic acid solution as a main component, the resin solution has a viscosity of 50 to 500 Pa · s, and the cylindrical gold is used when the coating film is uniformized. There is a configuration in which the rotation of the mold is controlled to be in a range of 1000 rpm to 4000 rpm.

  Further, as an embodiment of the manufacturing method, the method includes a step of rotating the cylindrical mold during the heat curing of the coating film, and the rotation speed is set to the cylindrical shape during the uniformization of the coating film. There is a configuration in which the rotation is controlled to be slower than the rotational speed of the mold. As a result, a high viscosity resin solution can be developed and uniformized in a short time with high speed rotation, and the coating film can be heated and cured at a lower speed than that, so that the film thickness is uniform without waviness and streaks, A seamless belt of a high-precision tubular body having surface accuracy can be suitably manufactured.

Diagram for explaining a seamless belt manufacturing apparatus Diagram for explaining a seamless belt manufacturing apparatus Diagram for explaining a seamless belt manufacturing apparatus The figure for demonstrating an example of a fixing means The figure for demonstrating an example of a fixing means The figure for demonstrating an example of a fixing means The figure for demonstrating an example of a fixing means

  Hereinafter, embodiments will be described with reference to the drawings as appropriate. In the manufacturing method of the seamless belt, first, a resin solution that is a molding material for the seamless belt is prepared. The resin solution has a high viscosity of 50 Pa · s or higher. Details of the resin solution will be described later. This resin solution is developed in a cylindrical mold. The method of spreading the resin solution on the inner surface of the cylindrical mold can be appropriately selected by a known method such as a die, a cylindrical nozzle, a dispenser for curtain coating, spray coating, roll coating or the like. In the case where the resin solution is polyamic acid, it is preferable to spirally apply the inner surface of the mold using a dispenser while rotating the cylindrical mold in the circumferential direction. The development may be developed on a part of the inner surface of the mold, and the developed film thickness is non-uniform before leveling.

  Next, the cylindrical mold in which the resin solution is developed is rotated at a high speed and leveled (homogenized) in a short time. In order to produce a seamless belt with high film thickness uniformity, coating film leveling by high-speed rotation of a cylindrical mold is necessary. Furthermore, it is important that the leveling of the coating film in the heat curing (drying) process is maintained. Therefore, at the time of homogenization after development, a cylindrical mold is rotated at a rotation speed of 1000 to 4000 rpm, and centrifugal force is applied to the developed coating film to form a developed coating film having a uniform coating thickness. In the heat curing (drying) step, it is preferable to cure by rotating the cylindrical mold at a lower rotational speed.

  FIG. 1 is an explanatory diagram showing an example of a seamless belt manufacturing apparatus. A resin solution has already been developed on the inner peripheral surface of the cylindrical mold 1. The cylindrical mold 1 is placed at a position previously positioned on a lifting platform 2 of an elevator. The lifting platform 2 and the cylindrical mold 1 are horizontal. The pair of conical cone chucks 3 and 4 have the same shape, their center axes (rotation center axes) are aligned and face each other, and stand by at the origin position.

  After the cylindrical mold 1 is placed on the lifting platform 2, when the start switch is turned on by operating the control panel of a control device (not shown), the lifting platform 2 is raised and the central axis of the cylindrical mold 1 is The lifting platform 2 stops at a position where the center axis (rotation center axis) of the conical cone chucks 3 and 4 coincides. When the size or height of the cylindrical mold 1 is previously input and stored in the control device, the ascent distance is calculated and automatic stop is possible.

  As another embodiment, when it is determined that the cylindrical mold 1 is in an appropriate predetermined posture with respect to the lifting / lowering table 2, the lifting / lowering table 2 can be automatically raised to a predetermined height. The cylindrical mold 1 is detected using a plurality of optical sensors, and it can be determined whether or not it is in the predetermined posture.

  Next, as shown in FIGS. 2 and 3, one conical cone chuck 3 is advanced by advancing / retreating drive means to a certain distance in the axial direction. Examples of the advance / retreat drive means include drive mechanisms such as a servo motor, an air cylinder, and a hydraulic cylinder.

  The other conical cone chuck 4 moves forward in its axial direction by the advancing / retreating drive means. As a result, both ends of the cylindrical mold 1 are fixed by pressure with the pair of conical cone chucks 3 and 4. In this case, the central axes of the conical cone chucks 3 and 4 and the cylindrical mold 1 coincide (concentrically), but for example, deformation of the end of the cylindrical mold 1 or the lift 2 The center axes of the conical cone chucks 3 and 4 and the cylindrical mold 1 do not coincide with each other due to causes such as vertical distortion, deformation of the conical cone chucks 3 and 4 and axial distortion of the advancing and retreating drive means. It is also assumed that it is not on the core. In such a case, the cylindrical die 1 and the conical cone chucks 3 and 4 are identical by determining whether or not the advance distances of the conical cone chucks 3 and 4 have reached a certain distance. Whether it is on the core can be determined (the function of the determination unit). If the cylindrical mold 1 and the conical cone chucks 3 and 4 are concentric, centrifugal molding by high-speed rotation is possible. It should be noted that the fact that they are concentric is not limited to that which means a coaxial in a strict sense, but shaft blurring in a range where high-speed rotation capable of achieving the object of the present invention is possible is allowed.

  Next, when the crimping and fixing of the conical cone chucks 3 and 4 and the cylindrical mold 1 is completed, the lifting platform 2 is lowered to the original standby position and shifts to a rotating operation (see FIG. 3). The cylindrical mold 1 is rotated around the main axis direction (broken line in FIG. 3) as a center of rotation and centrifugally formed to make the coating thickness uniform.

  The rotation speed at the time of this homogenization is in the range of 1000 rpm to 4000 rpm, more preferably 1500 rpm to 3500 rpm, and even more preferably 2500 rpm to 3500 rpm. If it is less than 1000 rpm, although it depends on the inner diameter of the cylindrical mold 1, it is difficult to give sufficient centrifugal force to the coating film thickness, the film thickness unevenness in the circumferential direction is likely to occur, and the coating film thickness is made uniform. This is not preferable because it takes time and the production cost increases. On the other hand, if it is greater than 4000 rpm, the centrifugal force applied to the coating liquid becomes too large, and therefore, film thickness unevenness is likely to occur in the width direction of the cylindrical mold 1, and in terms of energy efficiency and work safety in manufacturing. Is also not preferred. The rotation processing time is in the range of 30 seconds to 1 hour, and is set by the resin solution viscosity, the number of rotations, the cylindrical mold size, and the application amount of the resin solution.

  Next, when the rotation processing operation for equalization is completed, the lifting platform 2 is raised to a predetermined height, and the cylindrical mold 1 is brought into contact with the lifting platform 2. Next, the conical cone chucks 3 and 4 are retracted to the original position to release the crimping and fixing to the cylindrical mold 1. The cylindrical mold 1 is transferred to a heat curing (drying) process together with the coating film formed on the inner peripheral surface.

  Next, in the heat curing (drying) step, a seamless belt made of a polyimide resin can be obtained by a multistage heating method in which solvent removal and imide conversion are sequentially or partially performed by heating by a heating means. The heating temperature is appropriately determined according to the type of the solvent in the solvent removal step, but is generally about 60 to 200 ° C., and the imide conversion step is appropriately determined according to the polymer component to be constituted. It is about 200-400 degreeC. Although the heating time is appropriately set, both the solvent removal step and the imide conversion step are usually about 20 to 60 minutes. Moreover, in the heat curing (drying) step, when the cylindrical mold 1 is rotated, the rotational speed is set slower than the rotational speed of the cylindrical mold when the coating film is made uniform, For example, the range of 10 rpm-less than 1000 rpm is mentioned, 10 rpm-500 rpm are preferable and 10 rpm-100 rpm are more preferable.

  As another embodiment, the heat curing (drying) step may be performed by heating from the outer periphery of the cylindrical mold 1 with heating means while rotating the conical cone chucks 3 and 4. The rotation speed here can be set slower than the rotation speed of the cylindrical mold in the case of uniformization of the coating film, and examples include a range of 10 rpm to less than 1000 rpm, preferably 10 rpm to 500 rpm, and preferably 10 rpm to 100 rpm. Is more preferable.

(Constituent materials)
The material resin for the seamless belt includes a polyimide resin, etc., but the resin solution is mainly a polyamic acid solution that is thermosetting and suitable for a high viscosity resin, and is also heat resistant from the application side. Manufacturing method that is very suitable for finishing a seamless belt with excellent film thickness uniformity and flatness while molding a polyimide resin that can take advantage of excellent properties such as stability, mechanical strength, and chemical stability. It can be said.

  As the raw material liquid for the polyimide resin, for example, a solution of polyamic acid obtained by polymerizing tetracarboxylic dianhydride or its moving body and diamine in a solvent can be used. Any suitable tetracarboxylic dianhydride or diamine for forming the polyamic acid can be used.

  Specific examples of tetracarboxylic dianhydride include pyromellitic dianhydride (PMDA), 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride (BPDA), 3,3 ′, 4, 4'-biphenyltetracarboxylic dianhydride, 2,3,3 ', 4-biphenyltetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,5 6-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,2′-bis (3,4-dicarboxyphenyl) propane dianhydride, bis (3 4-dicarboxyphenyl) sulfone dianhydride, berylene-3,4,9,10-tetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, ethylenetetracarboxylic acid Anhydride, and the like.

Examples of the diamine include 4,4′-diaminodiphenyl ether (DDE), 4,4′-diaminodiphenylmethane, 3,3′-diaminodiphenylmethane, 3,3′-dichlorobenzidine, 4,4′-diaminodiphenyl sulfide 3,3′-diaminodiphenylsulfone, 1,5-diaminonaphthalene, m-phenylenediamine, p-phenylenediamine (PDA), 3,3′-dimethyl-4,4′-biphenyldiamine, benzidine, 3,3 '-Dimethylbenzidine, 3,3'-dimethoxybenzidine, 4,4-diaminophenylsulfone, 4,4'-diaminophenylsulfone, 4,4'-diaminodiphenylsulfide, 4,4'-diaminodiphenylpropane, 2, 4-bis (β-amino-tert-butyl) toluene, bis (p-β-amino-tert-butyl) Ruphenyl> ether, bis (p-β-methyl-6-aminophenyl) benzene, bis-P- (1,1-dimethyl-5-amino-pentyl) benzene, 1-isopropyl-2,4-m-phenylenediamine , M-xylylenediamine, p-xylylenediamine, di (p-aminocyclohexyl) methane, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, diaminopropyltetramethylene, 3-methyl Heptamethylenediamine, 4,4-dimethylheptamethylenediamine, 2,11-diaminododecane, 1,2-bis-3-aminopropoxyethane, 2,2-dimethylpropylenediamine, 3-methoxyhexamethylenediamine, 2,5 -Dimethylhexamethylene Amine, 2,5-dimethylheptamethylenediamine, 2,5-dimethylheptamethylenediamine, 3-methylheptamethylenediamine, 5-methylnonamethylenediamine, 2,11-diaminododecane, 2,17-diaminoeicosadecane, 1,4-diaminocyclohexane, 1,10-diamino-1,10 diamino-1,10-dimethyldecane, 1,12-diaminooctadecane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, Piperazine H ₂ N (CH ₂ ) ₃ O (CH ₂ ) ₂ O (CH ₂ ) NH ₂ , H ₂ N (CH ₂ ) ₃ S (CH ₂ ) ₃ NH ₂ , H ₂ N (CH ₂ ) ₃ N ( CH ₃ ) ₂ (CH ₂ ) ₃ NH ₂ , etc.

  Moreover, although a suitable thing can be used also as a solvent at the time of carrying out the polymerization reaction of the above-mentioned tetracarboxylic dianhydride and diamine, a polar solvent can be used preferably from points, such as solubility. N, N-dialkylamides are useful as examples of the polar solvent, and examples thereof include N, N-dimethylformamide and N, N-dimethylacetamide, which have low molecular weight. They can be easily removed from the polyamic acid and the polyamic acid molded article by evaporation, displacement or diffusion.

Examples of organic polar solvents other than the above include N, N-diethylformamide, N, N-diethylacetamide, N, N-dimethylmethoxyacetamide, dimethylsulfoxide, hexamethylbosboltriamide, N-methyl-2-pyrrolidone, Examples include pyridine, dimethyl sulfoxide, tetramethylene sulfone, dimethyl tetramethylene sulfone and the like. These may be used alone or in combination.
In the preparation of the polyamic acid, one or more samples can be used for each of the tetracarboxylic dianhydride, its derivative, diamine, and polar solvent.

  The ratio of tetracarboxylic dianhydride and the like to the diamine is generally equimolar, but is not limited thereto.

The monomer concentration at the start of the reaction can be appropriately determined depending on the reaction conditions and the like, but generally 5 to 30% by weight is appropriate.
In addition, carbon black such as ketjen black and acetylene black, metal such as aluminum and nickel, metal oxide compound such as tin oxide, conductive powder such as potassium titanate, or polyaniline and polyacetylene One type or two or more types of suitable conductive polymers can be used.

(viscosity)
The viscosity of the polyamic acid solution is about 50 to 1000 Pa · s, preferably about 100 to 800 Pa · s (B-type viscometer, rotor No. 7, 25 ° C.). When the viscosity is 50 Pa · s or less, so-called sagging or repellency of the coating layer is likely to occur, and it becomes difficult to obtain a uniform coating thickness. In addition, in such a low viscosity solution, there is a tendency that the solution supplied due to the decrease in the solution viscosity due to heating does not adhere to the inner peripheral surface of the mold, and the phenomenon that the solvent remains is reduced continuously by heating after coating. It is necessary to keep applying a certain centrifugal force, which is not preferable in terms of economy and cost. On the other hand, if it is 1000 Pa · s or more, it is necessary to apply a high pressure at the time of discharge, and molding during leveling becomes difficult, which is not preferable.

(Configuration of cylindrical mold)
The cylindrical mold 1 used in the present invention is made of aluminum, iron, brass, stainless steel or the like. It is also possible to apply a fluorine-based or silicon-based mold release agent on the inner surface in consideration of releasability from the mold.

  The inner diameter of the cylindrical mold 1 is not limited as long as it can be chucked by the pair of conical cone chucks 3 and 4 and the cone cone chucks 3 and 4 (FIG. 4). Further, the outer diameter of the cylindrical mold 1 is an outer diameter as long as it can be chucked by a pair of opposed inner surface truncated cone cone chucks 5 and 6 (FIG. 5) and three-point claw chucks 7 and 8 (FIG. 6). There is no limit.

(Fixing means)
As the pair of fixing means, the cone cone chucks 3 and 4 shown in FIG. 1, the trapezoid cone cone chucks 3 and 4 shown in FIG. 4, the inner cone cone chucks 5 and 6 shown in FIG. Three-point claw chucks 7 and 8 are illustrated. The peripheral surfaces (not shown) of the conical cone chucks 3 and 4 and the peripheral surfaces 31 and 41 of the trapezoidal cone chucks 3 and 4 are in contact with the inner edge portion of the end portion of the cylindrical mold 1. Further, the inner peripheral surfaces 51 and 61 of the inner cone cone chucks 5 and 6 abut against the outer edge portion of the end portion of the cylindrical mold 1. The three-point claw chuck 8 has three claws 81, 82, and 83, and each chucks the outer edge portion of one end of the cylindrical mold (the three-point claw chuck 7 has the same configuration). FIG. 7 is a schematic diagram for explaining the three-point claw chuck, but two claws are used for the sake of simplicity. In FIG. 7, each of the opposed pair of three-point claw chuck main body parts moves until they abut against the end of the cylindrical mold 1, and then the three-point claw part sandwiches the outer periphery of the end of the cylindrical mold 1. Fix it.

  The constituent materials of the various chucks are not particularly limited as long as a function capable of fixing the cylindrical mold 1 can be realized. For example, the surface can be made of metal, hard plastic, or the like.

  In addition, each of the pair of fixing means does not have to have the same shape and configuration. For example, one can be configured as a truncated cone cone chuck 3 and the other can be configured as an inner truncated cone cone chuck 6.

DESCRIPTION OF SYMBOLS 1 Cylindrical metal mold 2 Elevating stand 3, 4 Conical cone chuck, trapezoid cone cone chuck 5, 6 Inner surface cone cone chuck 7, 8, Three-point claw chuck

Claims (9)

A seamless belt manufacturing apparatus for rotating a cylindrical mold in which a resin solution is spread on the inner surface of a cylindrical mold and uniformizing a coating film,
A pair of fixing means for fixing both ends of the cylindrical mold, and a pair of fixing means arranged on opposite sides on the same core as the cylindrical mold;
Advancing / retreating drive means for moving the advancing / retreating in the axial direction of the cylindrical mold so as to fix the fixing means to the end of the cylindrical mold;
Rotation driving means for rotating the fixing means around its axis;
Lifting means for adjusting the arrangement of the cylindrical mold and the pair of fixing means facing each other on the same core;
The lifting / lowering means is automatically controlled so that the cylindrical mold and the pair of fixing means are arranged in a confronting pair on the same core, and the fixing means is automatically moved in the axial direction of the cylindrical mold. And a control means for automatically controlling the advancing / retreating drive means so as to fix the fixing means to the end of the cylindrical mold.
Whether the control means is arranged such that the cylindrical mold installed at a predetermined position of the lifting platform of the lifting means and the fixing means fixed to the end of the cylindrical mold are fixedly arranged on the same core. A determination unit that determines whether or not the fixing means is based on an advancing movement distance of the fixing unit, and the determination unit determines that the cylindrical mold and the fixing unit are fixedly disposed on the same core. In this case, the rotation of the fixing means by the rotation driving means can be automatically started,
The cylindrical mold is rotated by fixing both ends of the cylindrical mold with the pair of fixing means, rotating the fixing means with a rotation driving means, and rotating the cylindrical mold. Seamless belt manufacturing equipment. The seamless belt manufacturing apparatus according to claim 1, wherein the pair of fixing means are conical cone chucks. The seamless belt manufacturing apparatus according to claim 1, wherein the pair of fixing means is a claw chuck that sandwiches and fixes the outer periphery of the end of the cylindrical mold. The resin solution is a solution containing a polyamic acid solution as a main component, and the resin solution viscosity is 50 to 500 Pa · s,
4. The apparatus according to claim 1, further comprising a control unit configured to control the rotation driving unit so that a rotation speed of the cylindrical mold in the uniformization of the coating film is in a range of 1000 rpm to 4000 rpm. Seamless belt manufacturing equipment. Using the seamless belt manufacturing apparatus according to any one of claims 1 to 4, the cylindrical mold in which the resin solution is spread on the inner surface of the cylindrical mold is rotated to uniformize the coating film. And a step of heat curing the coating film on the inner surface of the cylindrical mold,
The cylindrical mold is fixed by fixing means so that both ends of the cylindrical mold are concentric with the cylindrical mold, and the fixing means is rotated around its axis, whereby the cylindrical mold is A method of manufacturing a seamless belt that rotates .
A cylindrical mold and a pair of fixing means installed at a predetermined position of the lifting platform automatically raise and lower the lifting platform so that they are arranged in a pair facing each other on the same core,
The fixing means is moved in the axial direction of the cylindrical mold, and the fixing means is automatically fixed to the end of the cylindrical mold,
The cylindrical mold and the fixing means are fixedly arranged concentrically on the basis of the advancing movement distance from the origin position to each of the cylindrical mold end portions. A method of manufacturing a seamless belt, wherein the rotation of the fixing means can be automatically started when it is determined that the fixing belt is rotating . The seamless belt manufacturing method according to claim 5, wherein the pair of fixing means are conical cone chucks . The seamless belt manufacturing method according to claim 5, wherein the pair of fixing means is a claw chuck that pinches and fixes an outer periphery of an end of the cylindrical mold . The resin solution is a solution containing a polyamic acid solution as a main component, and the resin solution viscosity is 50 to 500 Pa · s,
The method for producing a seamless belt according to any one of claims 5 to 7, wherein the rotation speed of the cylindrical mold at the time of uniformizing the coating film is controlled to be in a range of 1000 rpm to 4000 rpm. A step of rotating the cylindrical mold during the heat curing of the coating film, so that the rotation speed is slower than the rotation speed of the cylindrical mold during the uniformization of the coating film. The method for producing a seamless belt according to claim 8, wherein the rotation is controlled.

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