JP2017177038A - Manufacturing method of tubular material, coating device, and coating nozzle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain a stain by dripping under a core body of a coating film precursor solution and mixing-in of air when reusing the solution, and to uniformize a film thickness.SOLUTION: In a manufacturing method of a tubular material, a nozzle 102 having an inner diameter larger than an outer diameter of a core body, that is, the nozzle 102 having a die part 102a for regulating a film thickness of a coating film by a gap part α with the core body, a supply part 102b for supplying a solution of a coating film precursor to the gap part above the die part and a liquid reservoir part 107 for reserving the solution of becoming excessive in the die part or the supply part by scratching off by the gap part above the supply part, is substantially concentrically out-fitted to the columnar core body 101 of turning the central axis O-O in the substantially vertical direction, and is relatively passed in the upper direction to the core body, so that after being formed as the coating film by applying the solution of the coating film precursor to an outer surface of the core body, after being held in the core body until the coating film can hold strength as at least the tubular material, the tubular material is removed from the core body.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for manufacturing a tubular object such as a cylindrical endless belt (heating belt) used in an image heating apparatus that pressurizes and heats a toner image on a recording material. The present invention also relates to a coating apparatus and a coating nozzle for forming a film by applying a solution of a film precursor to the outer surface of a core body in order to produce a tubular product.

  In an image forming apparatus such as an electrophotographic system or an electrostatic recording system, an image heating apparatus that forms a toner image on a recording material (on a sheet) and heats and presses the toner image to fix the toner image on the recording material. A fixing device is provided. As such a fixing device, in recent years, an on-demand system having high heat transfer efficiency and quick start-up of the device is used from the viewpoint of energy saving. As this on-demand system, a belt heating system in which a recording material is heated via an endless fixing belt as a heating belt having a small heat capacity has been proposed.

  As a belt heating method, a recording material is conveyed to a nip portion between a fixing belt and a pressure roller as a nip forming member by sliding a ceramic heater as a fixed and supported heating body on the inner peripheral surface of the fixing belt. The structure which heats is proposed. Some fixing belts have a metal cylinder or a resin cylinder as a base material and are provided with an elastic layer or a surface layer. Of these, polyimide having excellent heat resistance and slidability may be used as the resin cylinder. The polyimide may be mixed with a filler such as carbon to improve thermal conductivity.

  As a method for manufacturing such a polyimide cylinder, a polyimide precursor solution is applied to the outer surface of the core body to form a film with a desired film thickness, and then the film retains at least strength as a tubular material. There is a method of taking out the tubular material from the core after heating it as much as possible.

  In Patent Document 1, a polyimide precursor solution is applied to the outer surface of a core body, a die is passed through the outside of the core body to form a film with a desired film thickness, and an excess of the applied polyimide precursor solution is received. This is a method of dropping into the tank. This method has a feature that it is easy to form a uniform film because a film thickness is defined by applying a shearing force to the polyimide precursor by passing it through a die.

  In Patent Document 2, an ejection slit head positioned at a predetermined gap is disposed outside the core body, and the coating precursor solution is transferred from the ejection slit head to the core body while moving each of the ejection slit heads. It is a method of discharging to the outer surface and cast molding to a predetermined film thickness. This method is characterized in that it is easy to control the start and end of discharge at both ends of the cylinder, and it is difficult for excessive coating to occur.

Japanese Patent Laid-Open No. 9-76363 JP 2004-291367 A

  However, in the technique of Patent Document 1, there is a possibility that the lower part of the core body may be soiled in a process in which an excess polyimide precursor solution is dropped into the lower layer. Moreover, when excess polyimide precursor was received in the tank, air was mixed in, and it was necessary to add a process such as vacuum defoaming in order to reuse this solution. In the technique of Patent Document 2, the pulsation of the discharge amount may occur as the membrane pressure of the tubular object.

  The objective of this invention is providing the manufacturing method of a tubular product, the coating apparatus, and the nozzle for coating which can solve this subject.

  In order to achieve the above object, a typical configuration of the method for manufacturing a tubular article according to the present invention is such that an inner diameter larger than the outer diameter of the core body with respect to a columnar core body whose central axis is directed in the vertical direction. A nozzle part for defining the film thickness of the film at a gap part with the core body, and a supply part for supplying a solution of the film precursor to the gap part above the die part And a nozzle that is above the supply unit and is scraped by the gap part and has a liquid reservoir part for storing the excess of the solution in the die part or the supply part. It is fitted and passed upward relative to the core body to apply a coating precursor solution to the outer surface of the core body to form a film, and then the film retains at least strength as a tubular object. After holding on the core until possible, the core Characterized in that removing the Luo tubing.

  In order to achieve the above object, a typical configuration of the coating apparatus according to the present invention is a coating apparatus in which a coating precursor solution is applied to the outer surface of a core to form a coating in order to produce a tubular product. A core device supporting mechanism capable of fixing and releasing the columnar core body in a posture in which the central axis is directed in the vertical direction, and a nozzle having an inner diameter larger than the outer diameter of the core body A die part for defining the film thickness of the film at a gap part with the core, a supply part that is above the die part and supplies a solution of the film precursor to the gap part, A nozzle having a liquid reservoir portion for storing the solution that has been scraped by the gap portion and surplused by the die portion or the supply portion, and located above the supply portion; To the core body in a state of being fitted substantially concentrically to the core body And having a nozzle moving mechanism for moving the nozzle to a solution of the coating precursor to the outer surface of the core by passing a relatively upward direction is applied to the coating.

  Further, a typical configuration of the coating nozzle according to the present invention for achieving the above object is that the inner diameter larger than the outer diameter of the core body with respect to the columnar core body whose central axis is directed in the vertical direction. And a nozzle that coats the outer surface of the core body as a coating film by being fitted substantially concentrically and passing it in a relatively upward direction. A die part for defining the gap part, a supply part that is above the die part and that supplies the solution to the gap part, and is above the supply part and scraped by the gap part And a liquid reservoir for storing the solution remaining in the die part or the supply part.

  According to the present invention, the possibility that the lower part of the core body is soiled can be reduced. In addition, it is possible to reuse the film precursor solution in which the liquid reservoir has been collected while omitting the step of defoaming. Further, since the pulsation of the discharge amount is relieved by the liquid reservoir, the film thickness unevenness hardly occurs.

Schematic diagram of the configuration of the main part of the coating apparatus in Example 1 Operation flowchart of the device Schematic diagram explaining the operation process of the device Nozzle cross-sectional schematic diagram Cross-sectional schematic diagram of the nozzle and the shutter held by the nozzle (part 1) Cross-sectional schematic diagram of the nozzle and the shutter held by the nozzle (part 2) Cross-sectional schematic diagram of nozzle moved to solution coating start position and shutter held by this nozzle Cross-sectional schematic diagram of the shutter that has been moved to the solution application end position Schematic diagram of nozzle cross-section being moved to solution coating start position Cross-sectional schematic diagram of the nozzle moved to the solution application end position and the shutter held by the nozzle Schematic cross-sectional view of the nozzle that has been moved upward from the solution coating end position to a predetermined position and the shutter held by the nozzle The figure at the time of the state which the core metal upper part support part moved to the raising position further from the state of Drawing 10B Cross-sectional schematic diagram showing the layer structure of the fixing belt FIG. 2 is a schematic cross-sectional view of a main part of the fixing device according to the first embodiment and a block diagram of a control system. Configuration schematic diagram of image forming apparatus in Embodiment 1 Schematic configuration diagram of the main part of the coating apparatus in Example 2 Cross-sectional schematic diagram of nozzle in the same device Schematic configuration diagram of the main part of the coating apparatus in Example 3 Operation flowchart of the apparatus (part 1) Operation flow chart of the apparatus (part 2)

Example 1
(Image forming device)
FIG. 13 is a schematic configuration diagram of an example of an image forming apparatus. This image forming apparatus is a four-color full-color image forming apparatus of an inline (tandem) method and an intermediate transfer method using an electrophotographic process.

  The image forming unit 20 that forms the toner image t on the recording material S includes four image forming stations U (Y, M, C, and K) that form toner images of yellow, magenta, cyan, and black, respectively.

  Each image forming station U has a photosensitive drum 1 (Y, M, C, K) as an image carrier. Further, as a process means for the photosensitive drum 1, a charging roller 2 (Y, M, C, K), an exposure device 3 (Y, M, C, K), and a developing device 4 (Y, M, C, K) are provided. ), A primary transfer roller 5 (Y, M, C, K) and a drum cleaner 6 (Y, M, C, K). Furthermore, the image forming unit 20 includes an intermediate transfer unit 7 including an intermediate transfer belt 8 that superimposes and conveys a toner image formed on the photosensitive drum 1 of each image forming station U.

  Since the image forming operation of the image forming unit 20 described above is well known, detailed description thereof is omitted. The recording material S is fed from a recording material supply unit (not shown) and introduced into a secondary transfer nip portion formed by the intermediate transfer belt 8 and the secondary transfer roller 9, and four colors are superimposed from the intermediate transfer belt 8 side. The toner image is transferred. The recording material S that has passed through the secondary transfer nip is introduced into the fixing device F, undergoes toner image fixing processing, and is discharged as a color image formed product. The toner remaining on the intermediate transfer belt 8 side without being transferred to the recording material S at the secondary transfer nip is removed by the belt cleaner 10.

(Fixing device)
FIG. 12 is a schematic cross-sectional view of a main part of a fixing device (image heating device) F in this embodiment and a block diagram of a control system. This fixing device F is an on-demand fixing device of a belt heating system-pressure rotary member driving system. The fixing device F is roughly divided into a belt unit 11 as a fixing member, and a pressure roller (pressure rotating body) as a nip forming member that forms a nip portion (fixing nip portion) N in cooperation with the unit 11. ) 12 and an apparatus frame (housing) 13 for housing them.

  The belt unit 11 includes a fixing belt (hereinafter referred to as a belt) 14 which is a flexible endless belt (endless belt: tubular product). In addition, a heater 15 serving as a heating member that also serves as a backup member, and a heater holder (heating member support member) 16 that supports the heater 15 are provided as internal members disposed inside the belt 14. The heater 15 and the heater holder 16 are members that are long in the longitudinal direction (the width direction and the generatrix direction) of the belt 14.

  In this embodiment, the heater 15 is a low-heat-capacity ceramic heater that raises the temperature with a steep rising characteristic as a whole by energizing the heating resistor layer. The heater holder 16 is formed of a liquid crystal polymer resin having high heat resistance, and plays a role of supporting the heater 15 and guiding the rotation of the belt 14. It also serves as a pressure stay. The heater 15 is fixed to and supported by the lower surface of the heater holder 16 along the length, and the inner surface of the belt 14 and the lower surface (heating surface) of the heater 14 are slidable.

  The pressure roller 12 is a heat-resistant elastic roller having a metal core 12a and an elastic layer 12b formed concentrically and integrally around the metal core. The pressure roller 12 is disposed such that both ends of the cored bar 12a are rotatably supported by bearings between one side and the other side (not shown) of the apparatus frame 13 in the longitudinal direction.

  The belt unit 11 is disposed substantially parallel to the pressure roller 12 with the heater 15 facing the upper side of the pressure roller 12. The both ends of the heater holder 16 are supported so as to be slidable in the direction toward the pressure roller 12 with respect to the side plates on one end side and the other end side in the longitudinal direction of the apparatus frame 13. Both end portions of the heater holder 16 are urged with a predetermined pressing force in a direction toward the pressure roller 12 by a pressure mechanism (not shown).

  Therefore, the heater holder 16 is urged toward the pressure roller 12, and the heater 15 is pressed against the pressure roller 12 through the belt 14 against the elasticity of the elastic layer 12b. As a result, a nip N having a predetermined width is formed between the belt 14 and the pressure roller 12 in the recording material conveyance direction a.

  The pressure roller 12 obtains a driving force that rotates at a predetermined peripheral speed in a counterclockwise direction indicated by an arrow R12 by a driving mechanism 17 provided at an end of the metal core 12a. The drive mechanism 17 is controlled by the control unit 18. As the pressure roller 12 rotates, the belt 14 slides in contact with the lower surface (heating surface) of the heater 15 at the nip portion N while the inner surface of the belt 14 slides against the pressure roller 12 at the nip portion N. Is driven to rotate in the clockwise direction of the arrow R14.

  The heater 15 is heated by being heated by energization from the power supply unit 19 controlled by the control unit 18. The control unit 18 controls power supplied from the power supply unit 19 to the heater 15 by a temperature control system (not shown) so that the heater 15 is raised to a predetermined temperature and maintained at that temperature.

  As described above, in a state where the pressure roller 12 is driven and the heater 15 is heated to a predetermined temperature, the recording material S carrying the unfixed toner image t is introduced into the nip portion N from the image forming portion 20 side. And nipped and conveyed. As a result, the recording material S is simultaneously heated and pressed in the nip portion N, and the toner image t is fixed to the recording material S as a fixed image. The portion of the recording material that has passed through the nip portion N is separated from the surface of the belt 14 and is discharged and conveyed.

(Fixing belt)
FIG. 11 is a schematic cross-sectional view of the belt showing the layer structure of the belt 14. The belt 14 in this embodiment has a five-layer structure having flexibility as a whole with the innermost side being the resin base material 14a. That is, an elastic layer 14c is provided on the outer peripheral surface of the resin base material 14a via a primer layer 14b, and a release layer 14e is formed on the surface of the elastic layer 14c via an adhesive layer 14d.

  Examples of the material used as the resin base material 14a include polyimide resin, polyimide resin, polyamide resin, polyether ether ketone resin, polyether sulfone resin, and polyamide imide resin. In the belt 14 of the present embodiment, the resin base material 14a is made of polyimide and has a cylindrical shape with a thickness of 60 μm, an inner diameter of 24 mm, and a length of 380 mm. Hereinafter, the resin base material 14a is referred to as a polyimide base material 14a.

  As the elastic layer 14c, fluorine rubber, silicone rubber or the like having heat resistance and elasticity is used. The elastic layer 14c of the present example is a silicone rubber having a thickness of 200 μm. The release layer 14e is preferably a material having releasability with respect to the toner. The release layer 14e of this example is a tetrafluoroethylene perfluoroalkyl vinyl ether copolymer (PFA) having a thickness of 30 μm.

(Polyimide substrate 14a)
The resin base material 14a of the belt 14 of the present embodiment is made of polyimide resin as described above. The polyimide base material 14a is formed as follows, for example. A solution of a polyimide precursor as a coating precursor obtained by reacting approximately equimolar amounts of an aromatic tetracarboxylic dianhydride or its derivative and an aromatic diamine in an organic polar solvent, a core (molding die) It is formed by coating, drying, and heating on the outer peripheral surface of the film, and a dehydration ring-closing reaction.

  The polyimide precursor solution is preferably an aromatic polyimide precursor. For this purpose, each polyimide precursor consists of, for example, an aromatic tetracarboxylic acid and an aromatic diamine. Typical examples of the aromatic tetracarboxylic acid include the following. Pyromellitic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 2,3,6,7 , -Naphthalene tetracarboxylic dianhydride, and the like.

  These aromatic tetracarboxylic acids can be used alone or in combination of two or more. These aromatic diamines can be used alone or in combination of two or more.

  These polyimide precursors are reacted with an organic polar solvent to form a polyimide precursor solution so that this polyimide precursor can be applied to the core. Examples of the organic polar solvent include dimethylacetamide, dimethylformamide, N-methyl-2-pyrrolidone, phenol, O-, M-, and P-cresol.

  In this example, N-methyl-2-2, which is a polyimide precursor using 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride as an aromatic tetracarboxylic acid and paraphenylenediamine as an aromatic diamine, is used. The pyrrolidone solution was used as a polyimide precursor solution. The viscosity of the polyimide precursor solution is about 1 to 10000 Pa · sec, more preferably 10 to 1000 Pa · sec.

The polyimide precursor solution may contain an inorganic filler for the purpose of imparting thermal conductivity or wear resistance. Examples of inorganic fillers include silicon carbide (SiC), silicon nitride (Si ₃ N ₄ ), boron nitride (BN), aluminum nitride (AlN), alumina (Al ₂ O ₃ ), zinc oxide (ZnO), and magnesium oxide (MgO). ) And silica (SiO ₂ ). Further, molybdenum disulfide (MoS ₂ ), graphite, titanium nitride (TiN), mica (mica), synthetic mica, and the like can be given.

(Characteristic part of this embodiment)
The manufacturing method and manufacturing apparatus of the resin base material 14a by the above-mentioned polyimide resin will be described. FIG. 1 is a schematic configuration diagram of a main part of a ring coating method coating apparatus (hereinafter referred to as a coating apparatus) 100 in the present embodiment. Here, in the following description, “upper and lower” means upper and lower in the direction of gravity.

  The coating apparatus 100 is used as a columnar core body (molding die, mold: hereinafter referred to as a core metal) 101 such as aluminum or stainless steel. The metal core 101 includes a metal core lower support portion 114 and a metal core upper support portion 113 that support the metal core 101 in a vertical orientation in which the direction of the central axis OO (virtual line: hereinafter referred to as an axis) is the vertical direction. The angle between the central axis OO of the cored bar 101 and the vertical line in the vertical direction may not be strictly parallel, but the angle is preferably within 5 ° (substantially vertical direction).

  The coating apparatus 100 includes a coating nozzle 102. The nozzle 102 has an inner diameter larger than the outer diameter of the cored bar 101, and is relatively upward with respect to the cored bar 101 from the bottom as indicated by an arrow A in a state of being fitted on the cored bar 101 substantially concentrically. The polyimide precursor solution is applied to the outer surface of the cored bar 101 as a coating.

  The coating apparatus 100 also includes a shutter 108 as a masking member for sealing a gap portion (coating gap portion) between the cored bar 101 and the nozzle 102. As will be described later, the shutter 108 is fitted on the core metal 101 substantially concentrically and is detachable from the nozzle 102.

  The nozzle 102 is a ring-shaped member having a cross-sectional shape as shown in FIG. 4 and includes a solution supply port 103. The solution supply port 103 is connected to the first pump mechanism 111 through the flexible tube 104 as shown in FIG. The first pump mechanism 111 is controlled by the control unit 200 and supplies the polyimide precursor solution stored in the solution tank 110 between the nozzle 102 and the cored bar 101 through the tube 104 and the solution supply port 103.

  The nozzle 102 is axially OO of the cored bar 101 in a state of being fitted on the cored bar 101 substantially concentrically by the operation of the first moving mechanism (nozzle moving mechanism) 115 controlled by the control unit 200. Can be moved vertically. When the polyimide precursor solution is applied to the cored bar 101, the first moving mechanism 115 is operated to move upward relative to the cored bar 101, that is, upward in the arrow A. The lowermost part of the nozzle 102 is a die part 102a for defining the film thickness of the coating formed on the outer surface of the cored bar 101 with a gap part (hereinafter referred to as a coating gap) α with the cored bar 101. In the embodiment, the coating gap α is 0.6 mm.

  A solution supply nozzle 102 b is provided above the die portion 102 a, and the polyimide precursor solution pushed out in the direction of arrow B by the first pump mechanism 111 passes between the nozzle 102 and the core metal 101 through the tube 104 and the solution supply port 103. Supplied in between. The upper part (shaded part in FIG. 4) of the nozzle 102 is a liquid reservoir part 107, which holds the excess polyimide precursor solution.

  The shutter 108 is a ring-shaped member having a cross-sectional shape as shown in FIG. 5, and includes a polyimide precursor solution coating start portion at the lower end portion of the core metal by the nozzle 102 and a polyimide precursor solution coating end portion at the upper end portion of the core metal. It is a member used for so-called masking for forming. The shutter 108 has an inner diameter of 24 mm, which is substantially the same as the outer diameter of the cored bar 101, and the outer surface has an inverted triangular (wedge shape) cross section. The thickness of the upper end of the shutter 108 is 2 mm, and the thickness of the lower end is 0.4 mm.

  The shutter 108 is externally fitted to the cored bar 101 on the upper side of the nozzle 102, and can move up and down concentrically along the axis OO of the cored bar 101. The shutter 108 is supported by a second moving mechanism (masking member moving mechanism) 116 controlled by the control unit 200 and moved up and down. Alternatively, the shutter 108 is moved up and down together with the nozzle 102 moved by the first moving mechanism 115 when the support by the second moving mechanism 116 is released and supported by the nozzle 102.

  The cored bar 101 is moved for attachment to the coating apparatus 100 and moved for removal by the operation of the third moving mechanism 117 controlled by the control unit 200. Further, the cored bar upper support portion 113 is moved in the vertical direction by the operation of the fourth moving mechanism 118 controlled by the control unit 200. The cored bar upper support 113 is moved downward to support and support the cored bar 101 in a vertical orientation between the cored bar lower support 114 and moved upward. Release the fixed support. In the present embodiment, the metal upper support portion 113, the metal core lower support portion 114, and the fourth moving mechanism 118 constitute a core body support mechanism.

  In the coating apparatus 100 of the present embodiment, the pump mechanism 111 and the moving mechanisms 115 to 117 are subjected to predetermined sequence control by the control unit 200, and the operation of the apparatus is centrally controlled. In addition, although the specific mechanism structure is abbreviate | omitted in the figure, in order to avoid the complexity of a figure, the moving mechanisms 115-117 can employ | adopt an appropriate mechanism structure. For example, moving mechanism using rack and pinion, moving mechanism using gear and chain or timing belt, moving mechanism using screw rod and slider, moving mechanism using electromagnetic solenoid, moving mechanism using hydraulic pressure, gripping tool An appropriate mechanism configuration such as a moving mechanism having the above can be adopted.

  An outline of the operation of the coating apparatus 100 will be described with reference mainly to the flowchart of FIG. 2 and FIG.

  As shown in FIG. 3A, the nozzle 102 has a home position 102 </ b> A that corresponds to a predetermined position with respect to the cored bar lower support portion 114. In addition, the lower position where the shutter 108 is fitted into the nozzle 102 located at the home position 102A while being supported by the second moving mechanism 116 is the home position 108A.

  Further, the upper support portion 113 of the metal core is actuated by the fourth moving mechanism 118, and as shown by a two-dot chain line in FIG. 3A, a predetermined lowered position 113A and a solid line that is raised to a predetermined level from the lowered position 113A. It can move between the raised position 113B shown. The descending position 113A of the core metal upper support portion 113 is a position where the core metal 101 is fixed and supported between the core metal lower support portion 114 and the vertical position. The raised position 113 </ b> B is a position where the metal core 101 can be detached from the coating apparatus 100 by releasing the fixed support of the core metal 101 or a position where the core metal 101 can be attached to the coating apparatus 100.

  Step (Process) S1: In preparation for mounting the cored bar 101 to the coating apparatus 100, the control unit 200 operates the first moving mechanism 115 when the nozzle 102 is not positioned at the home position 102A, and is positioned at the home position 102A. Let Further, when the shutter 108 is not positioned at the home position 108A, the second moving mechanism 116 is operated to be positioned at the home position 108A. Further, when the cored bar upper support portion 113 is not located at the raised position 113B, the fourth moving mechanism 117 is operated to be located at the raised position 113B. FIG. 3A shows this state of the apparatus.

  Step S2: The control unit 200 releases the support of the shutter 108 located at the home position 108A by the second moving mechanism 116. As a result, the shutter 108 released from the support by the second moving mechanism 116 moves slightly downward due to its own weight and falls with respect to the nozzle 102 located at the home position 102A. In this depressed state, as shown in FIGS. 5 and 6, the shutter 108 closes the coating gap α, and at the same time, the shutter 108 is supported by being in contact with the nozzle 102 or substantially in contact with the polyimide precursor solution. .

  Step S3: The controller 200 operates the third moving mechanism 117 supporting the cored bar 101 to attach the cored bar 101 to the apparatus, and the cored bar 101 is positioned at the raised position 113B. It moves in a vertical orientation between the upper support part 113 and the cored bar lower support part 114. Then, the lower end portion of the cored bar 101 is inserted so as to match the inner diameter hole of the shutter 108 supported by the nozzle 102 located at the home position 102A as shown in FIG. The lower end surface of 101 is received by the lower metal core support portion 114.

  In this embodiment, the cored bar 101 has a cylindrical shape with a diameter of 24 mm and a height (length) of 400 mm, and a release layer is formed on the surface. As a mold release agent, “Ceramica (trade name)” manufactured by Niita Laboratory Co., Ltd. can be used.

  Step S4: The controller 200 operates the fourth moving mechanism 118 to move the cored bar upper support 113 downward to the lowered position 113A. As a result, as shown in FIG. 3C, the cored bar 101 is in a vertical orientation with the axial direction OO being the vertical direction between the cored bar lower support part 114 and the cored bar upper support part 113. Fixedly supported. That is, the metal core 101 is fixed between the metal core lower support part 114 and the metal core upper support part 113 so that the central axis thereof substantially coincides with the central axis of the nozzle 102.

  Further, the control unit 200 operates the third moving mechanism 117 to release the support of the cored bar 101 and moves the third moving mechanism 117 to a predetermined standby position retracted from the cored bar 101.

  Step S5: The control unit 200 operates the first moving mechanism 115 to raise the nozzle 102 holding the shutter 108 from the home position 102A. Then, as shown in FIG. 3 (d), the lower surface 102 c of the nozzle 102 is stopped so as to reach a rising position 102 </ b> B of 10 mm above the lower surface 101 a of the core metal 101. The rising position 102 </ b> B of the nozzle 102 is a position (a predetermined lower position) at which the polyimide po precursor solution starts to be applied to the lower end portion of the core metal by the nozzle 102. At this time, the lower part of the coating apparatus 100 is as shown in FIG.

  Step S <b> 6: The control unit 200 operates the second moving mechanism 116 to hold and raise the shutter 108 and pull it out of the nozzle 102. Then, the shutter 108 is further moved upward so that the lower end surface 108a of the shutter 108 is positioned 10B lower than the upper end surface 101b (FIG. 8) of the core metal 101 as shown in FIG. To. The ascending position 108B of the shutter 108 is the polyimide po precursor solution coating finish position (predetermined upper position) at the upper end of the core metal by the nose 102.

  That is, the operation of the shutter 108 is an operation for waiting the shutter 108 at the position where the polyimide precursor solution is applied to the core metal 101. At this time, the upper part of the coating apparatus 100 is as shown in FIG. 8, and the lower part of the coating apparatus 100 is as shown in FIG.

  Step 7: The control unit 200 operates the first pump mechanism 111 in the apparatus state of FIG. 3E and FIG. 9 to fill a predetermined amount of the polyimide precursor solution between the cored bar 101 and the nozzle 102.

  Step S8: After step 7, the control unit 200 places the apparatus 100 in a standby state for a predetermined time. During this time, the liquid level of the polyimide precursor solution between the cored bar 101 and the nozzle 102 is stabilized.

  Step S9: The controller 200 causes the first moving mechanism 115 to raise the nozzle 102 at a predetermined speed. This step S9 is a “coating process”, and FIG. In FIG. 1, reference numeral 104 a-1 denotes a coating layer (coating film) of a polyimide precursor solution applied to the outer surface of the core metal 101 by moving the nozzle 102 from below to above along the axis OO of the core metal 101. ).

  The predetermined speed varies depending on the viscosity of the polyimide precursor solution, but is 0.1 mm / sec or more and 100 mm / sec or less, preferably 0.5 mm / sec or more and 50 mm / sec. If it is slower than this range, it takes a long time for coating, and there is a risk of sagging of the polyimide precursor solution at the lower part of the nozzle 102. If it is earlier than this range, the polyimide precursor solution in the nozzle 102 may not follow and coating unevenness may occur.

  In the coating process, by shearing the polyimide precursor solution supplied to the die part 102a, the solution becomes a film having a constant film thickness (predetermined film thickness) and adheres to the cored bar 101. That is, since the film thickness can be defined by the gap between the cored bar and the die, it is easy to form a uniform film. Thereby, the film | membrane pressure change by the pressure change at the time of the 1st pump mechanism 111 discharging a polyimide precursor solution can be suppressed to the minimum.

  A surplus of the polyimide precursor solution scraped upward by the die portion 102 a is held in the liquid reservoir portion 107. That is, a polyimide precursor solution is prepared by moving a die having an upper holding portion for holding a polyimide precursor solution upward with respect to a cored bar and accumulating excess polyimide precursor solution in a reservoir. The dripping of below is suppressed. By adopting such a configuration, it is possible to minimize the phenomenon in which the polyimide precursor solution is scraped downward and stains the lower portion of the core metal 101.

  Step S10: Performed in parallel with Step S9 described above, the control unit 200 operates the first pump mechanism 111 to replenish the polyimide precursor solution that has been discharged from the nozzle 102 in the coating process.

  Step S11: The control unit 200 moves the nozzle 102 to the position 102C (FIG. 3 (f)) where the nozzle 108 positioned at the upper position 108B substantially contacts the die part 102a by the operation of the first moving mechanism 115. Raise. Thereby, the coating layer 14a-1 of the polyimide precursor solution is applied to the 380 mm length portion between the 10 mm width portion at the lower end portion and the 10 mm width portion at the upper end portion with respect to the core metal 101 having a total length of 400 mm. Is formed.

  Thereafter, the holding of the shutter 108 by the second moving mechanism 116 is released. At this stage, the shutter 108 is substantially fitted to the die portion 102 a by its own weight, and the supply of the polyimide precursor solution to the core metal 101 is stopped. This state is shown in FIG. 10A.

  Step S12: The control unit 200 operates the first moving mechanism 115 to move up the nozzle 102 in a state where the shutter 108 is supported. Then, as shown in FIG. 10B, the shutter 108 is moved up to a position (predetermined upper position) 102D at which the lower end surface 108a of the shutter 108 becomes a height at which the core metal 101 can be removed and stopped. During this step S12, since the shutter 108 is substantially fitted to the die portion 102a by its own weight and the frictional force with the core metal 101, the adhesion of the polyimide precursor solution to the upper portion of the core metal 101 can be minimized. it can.

  Step S13: The control unit 200 operates the third moving mechanism 117 to hold the cored bar 101.

  Step S14: The control unit 200 operates the fourth moving mechanism 118 to move the cored bar upper support part 113 from the lowered position 113A to the raised position 113B as shown in FIG. To do.

  Step S15: The control unit 200 operates the third moving mechanism 117 to move the cored bar 101 to the outside of the coating apparatus 100.

  FIG. 3G shows a cored bar 101 that has been applied from the coating apparatus 100 and has been coated with a polyimide precursor solution. 101A is a coating portion having a length of 380 mm where the polyimide precursor solution of the core metal 101 is applied, and 101B is an uncoated portion having a width of 10 mm at each of the lower end portion and the upper end portion of the core metal 101.

(Solidification of polyimide precursor)
The polyimide precursor solution coating layer 104 a-1 of the core metal 101 taken out from the apparatus 100 is dried with an organic polar solvent by hot air drying or the like while attached to the core metal 101. After that, the solid polyimide base material 14a is obtained by a dehydration ring-closing reaction by being heated at around 300 ° C. That is, heating is performed until the polyimide precursor solution coating layer 104a-1 can maintain at least strength as a tubular product. Thereafter, an external force is applied to this to release it from the cored bar 101.

  At this time, if the cored bar 101 is made of a material such as aluminum having a high linear expansion coefficient, the inner diameter of the polyimide base material 14a after the dehydration-closure reaction is determined at the time of thermal expansion of the cored bar 101. Since the gold 101 is contracted, it is easy to remove the mold.

  The configuration of this embodiment is simple compared to the configurations of Embodiments 2 and 3 described below. In the configuration of the present embodiment, the supply amount p (l / sec) of the first pump mechanism 111 per unit time is adjusted to a predetermined range, or the operator collects liquid according to the predetermined number of times of coating. It is preferable to monitor the liquid level of the unit 107 and finely adjust the supply amount p (l / sec).

Example 2
FIG. 14 and FIG. 15 are configuration schematic diagrams of the main part of the coating apparatus 100 according to the second embodiment. The coating apparatus 100 of this embodiment is provided with a solution suction port 105 and a second pump mechanism 112 in addition to the coating apparatus 100 of the first embodiment.

  That is, as shown in FIG. 15, a suction nozzle (solution recovery nozzle: suction part) 102 d for sucking excess solution is provided to the liquid reservoir part 107 of the nozzle 102. The second pump mechanism 112 sucks the polyimide precursor solution in the reservoir 107 through the suction nozzle 102d, the solution suction port 105, and the flexible tube 106 in the direction of arrow C in FIG.

  Since the other apparatus configuration is the same as that of the apparatus 100 of the first embodiment, the same reference numerals are given and the description thereof is omitted.

  The operator adjusts the supply amount p (l / sec) of the first pump mechanism 111 as compared with the first embodiment by causing the second pump mechanism 112 to be appropriately operated by the operator operating the operation unit 201 of the control unit 200. The width to do is widened. The operator can arbitrarily set the suction amount q (l / sec) of the second pump mechanism 112 per unit time and the operation timing thereof. Overflow of the polyimide precursor solution from the liquid reservoir 107 can be efficiently prevented, and the interval for monitoring the liquid surface of the liquid reservoir 107 can be lengthened.

  However, the operator needs to confirm that the liquid surface of the liquid reservoir 107 sufficiently covers the suction nozzle 102d in order to prevent air suction by the suction nozzle 102d. If the suction of air is prevented by checking the liquid level, there is no mixing of air into the solution tank 110, and there is no need for trouble such as defoaming the collected liquid. Thus, the polyimide precursor solution can be reused while omitting the defoaming step by sucking the polyimide precursor solution accumulated in the liquid reservoir without mixing the air.

Example 3
FIG. 16 is a schematic configuration diagram of the main part of the coating apparatus of the third embodiment, which is a further development of the coating apparatus 100 of the second embodiment. That is, the coating apparatus of the present embodiment is provided with the laser displacement meter 108 in addition to the coating apparatus 100 of the second embodiment. A laser displacement meter (laser length measuring device: liquid amount detection unit) 210 detects the liquid level of the liquid reservoir 107 of the nozzle 102 via the folding mirror 211.

  The unit of the laser displacement meter 210 and the folding mirror 211 is supported by the nozzle 102 and is moved up and down together with the nozzle 102 while maintaining a predetermined positional relationship with the nozzle 102. Alternatively, the nozzle 102 is supported by the first moving mechanism 115 that moves the nozzle 102 up and down together with the nozzle 102 and is moved up and down together with the nozzle 102 while maintaining a predetermined positional relationship with the nozzle 102. The laser displacement meter 210 is connected to the control unit 200 and transmits the detection result x to the control unit 200 in response to an instruction from the control unit 200.

  Since the other apparatus configuration is the same as that of the apparatus 100 of the second embodiment, the same reference numerals are given and the description thereof is omitted.

  FIG. 17 is a flowchart for explaining the operation of the coating apparatus of this embodiment. The outline is the same as the flowchart of FIG. The difference is that the operation of the first pump mechanism 111 and the second pump mechanism 112 is controlled based on the detection result of the laser displacement meter 210 in step S10.

  FIG. 18 is a flowchart of the control content of step S10 of FIG. This flow is performed in parallel with step S9 of FIG. 17 following step S8 of FIG.

  In step S <b> 21, the laser displacement meter 210 detects the liquid level in the nozzle 102 and transmits the detection result x to the control unit 200.

  In step S22, it is determined whether or not the detection result x is greater than or equal to the first threshold value α. The threshold value α is obtained by removing the volume of the shutter 108 and the amount of liquid that may be attached to the shutter 108 from the volume of the shutter 108 in the liquid level detection result. It is a boundary of whether or not it is sufficient. In the case of the present embodiment, specifically, the liquid level covers the solution supply nozzle 102b in a state where the shutter 108 is inserted into the die portion 102a.

  In the case of N in step S22, there is a risk of coating failure due to insufficient solution, and it is suspected that the apparatus is abnormal or insufficiently adjusted. Therefore, the control unit 200 interrupts the flow of FIG. 17 and stops the operation of the coating apparatus 100. To do. In this case, the control unit 200 displays on the display unit of the operation unit 201 a message prompting the operator to check.

  In the case of Y in step S22, it is subsequently determined in step S23 whether or not the detection result x is equal to or less than the second threshold value β. In the case of N in step S23, before operating the second pump mechanism 112, the control unit 200 acquires the detection result x from the laser displacement meter 210 again in step S24, and then in step S25, the latest detection result x is obtained. Confirm that it is greater than the third threshold γ.

  The third threshold value γ is a boundary of whether or not the polyimide precursor solution sufficiently covers the solution recovery nozzle 102d. If x is γ or more, air is not sucked from the solution recovery nozzle 102d. On the other hand, if x is smaller than γ, air may be sucked from the solution recovery nozzle 102d, and the effect of continuously performing stable coating is lost.

  In theory, α <γ <β should be satisfied, and N should not be satisfied in step S25, and step S25 seems unnecessary at first glance. However, since the polyimide precursor solution has a predetermined viscosity, the possibility that the liquid level is gradually changed is taken into consideration, and the possibility of sucking air from the solution recovery nozzle 102d is minimized. To.

  As described above, the control unit 200 does not perform the operation of sucking the solution by the solution recovery nozzle 102d when the liquid level of the liquid reservoir 107 of the nozzle 102 detected by the laser displacement meter 210, that is, the liquid amount is equal to or less than a predetermined amount. Thereby, the polyimide precursor solution can be reused, omitting the defoaming step, by sucking the polyimide precursor solution accumulated in the liquid reservoir without mixing the air.

  After such confirmation in step S25, if the result is N, the apparatus 200 is suspected of being abnormal or insufficiently adjusted, so the control unit 200 interrupts the flow of FIG. Stop operation. In this case, the control unit 200 displays on the display unit of the operation unit 201 a message prompting the operator to check.

  In the case of Y in step S25, the first pump mechanism 111 is stopped and the second pump mechanism 112 is operated in step S26, and the excess polyimide precursor solution is recovered.

  In the case of Y in step S23, an amount sufficient to adhere to the cored bar 101 by the coating process in step S26 or a slightly larger amount of polyimide precursor solution is moved into the nozzle 102 by operating the first pump mechanism 111. The second pump mechanism 112 is stopped.

  Subsequently, in step S28, it is confirmed whether or not the coating process is completed. If Y is determined in step S28, the first pump mechanism 111 and the second pump mechanism 112 are stopped in step S29 and the process ends. If N in step S28, the process returns to step S21 to continue the coating operation.

  In the present embodiment, by using the laser displacement meter 210 and performing the coating process based on the flowchart as shown in FIG. 18, continuous and stable coating can be performed without attaching an operator.

  Further, since the supply amount p (l / sec) of the first pump mechanism 111 per unit time and the amount q (l / sec) of the polyimide precursor solution recovered by the second pump mechanism 112 are also increased, allowable ranges become large. Easy to adjust.

  Although three embodiments have been described above, the present invention is not necessarily limited to the above-described configuration, and modifications can be made as appropriate within a range where desired effects can be obtained. For example, in the third embodiment, two threshold values are provided so that the liquid level is maintained between them. However, the target value y of the detection result x is determined, and if it falls below it, it may be supplied, and if it goes above, it may be recovered. Good.

  Moreover, although the optical type was mentioned as an example for the detection of a liquid level, you may use the contact-type displacement meter which contacts and displaces a liquid level. Further, it is preferable that r (l / sec) is equal to qp (l / sec) where r (l / sec) is the amount of polyimide precursor solution applied to the core metal 101 per unit time.

  Further, the film precursor solution is not limited to the polyimide precursor solution of the examples. A solution of a precursor for film formation such as other thermosetting resins can also be used.

  100 ... Coating device 101 ... Core body 102 ... Nozzle 102a ... Dice part 102b ... Supply part 107 ... Solution part α ... Gap part 104a-1 ... Coating 108 .. Masking member

Claims (13)

  A nozzle having an inner diameter larger than the outer diameter of the core body with respect to a columnar core body whose central axis is directed substantially in the vertical direction, in order to define the film thickness of the coating film by a gap portion with the core body A die part, a supply part that is above the die part and supplies the solution of the film precursor to the gap part, and is above the supply part and scraped by the gap part, A nozzle having a liquid reservoir for storing the excess solution in the supply section is fitted substantially concentrically and passed upward relative to the core to allow the core to After the coating precursor solution is applied to the outer surface to form a coating, the coating is held on the core until the coating can maintain at least strength as a tubular, and then the tubular is removed from the core. A method for producing a tubular product. By fitting a nozzle having an inner diameter larger than the outer diameter of the core body to a columnar core body whose central axis is substantially directed in the vertical direction, and passing the nozzle body relatively upward with respect to the core body. After the coating precursor solution is applied to the outer surface of the core body to form a coating film, the tubular body is removed from the core body after being held on the core body until the coating film can maintain at least strength as a tubular body. A method for manufacturing a product,
The nozzle includes a die part for defining a film thickness of the coating film by a gap part with the core body, a supply part that is above the die part and supplies the solution to the gap part, and the supply part A reservoir portion for storing the solution that has been scraped by the gap portion and surplus in the die portion or the supply portion,
Using a masking member removable from the nozzle for sealing between the core and the nozzle in the die part,
A first step of retracting the nozzle and the masking member downward relative to the core;
A second step of fixing the core body so that a central axis thereof substantially coincides with a central axis of the nozzle;
A third step of moving the nozzle and the masking member relative to the core to move to a predetermined solution coating start position where the lower end surface of the nozzle is above the lower end of the core; ,
A fourth step of moving the masking member upward with respect to the nozzle, and moving the masking member to a predetermined solution coating end position where the lower end surface of the masking member is below the upper end of the core;
While supplying the solution from the supply unit to the die part while raising the nozzle relative to the core body at a predetermined speed, shearing is applied to the solution by the die part. A fifth step of forming the film having a predetermined thickness on the outer surface;
A sixth step of raising the nozzle to a position where the masking member located at the solution coating end position substantially contacts the die portion;
The height at which the nozzle and the masking member are moved upward relative to the core body so that the lower end surface of the masking member is above the upper end portion of the core body and the core body can be removed. A seventh step of moving to a position where
An eighth step of moving to remove the core;
A method for producing a tubular article characterized by comprising:   The method for producing a tubular article according to claim 1 or 2, wherein a suction part for sucking the accumulated solution is provided in the liquid reservoir part.   A liquid amount detection unit for detecting the amount of the solution accumulated in the liquid reservoir, and when the liquid amount detected by the liquid amount detection unit is a predetermined amount or less, the suction unit The method for producing a tubular article according to claim 3, wherein a suction operation is not performed.   The method for manufacturing a tubular article according to any one of claims 1 to 4, wherein the coating formed on the outer surface of the core body is heated until at least the strength of the tubular article can be maintained.   The method for producing a tubular product according to any one of claims 1 to 6, wherein the coating film precursor is a polyimide precursor. A coating apparatus for forming a film by applying a solution of a film precursor to the outer surface of a core body to produce a tubular object,
A core support mechanism capable of fixing and releasing the columnar core in a posture in which the central axis is substantially directed in the vertical direction;
A nozzle having an inner diameter larger than the outer diameter of the core body, a die portion for defining the film thickness of the coating film by a gap portion with the core body, and above the die portion and in the gap portion A supply unit for supplying a solution of the film precursor; and a liquid that is above the supply unit and is scraped by the gap unit and for storing the excess solution from the die unit or the supply unit. A nozzle having a reservoir,
In order to apply the coating precursor solution as a coating on the outer surface of the core body by allowing the nozzle to pass upward relative to the core body in a state where the nozzle is fitted on the core body substantially concentrically. And a nozzle moving mechanism for moving the nozzle.   A masking member that is detachable from the nozzle and that forms a solution coating start portion at the lower end portion and a solution coating end portion at the upper end portion of the core, and a masking member moving mechanism that moves the masking member. The coating apparatus according to claim 7.   The coating apparatus according to claim 7 or 8, wherein the liquid reservoir is provided with a suction part for sucking the accumulated solution.   A liquid amount detection unit for detecting the amount of the solution accumulated in the liquid reservoir, and when the liquid amount detected by the liquid amount detection unit is a predetermined amount or less, the suction unit The coating apparatus according to claim 9, wherein suction operation is not performed.   The coating apparatus according to claim 7, wherein the coating film precursor is a polyimide precursor.   An inner diameter larger than the outer diameter of the core body with respect to a columnar core body whose central axis is directed substantially in the vertical direction is fitted substantially concentrically and passes relatively upward, thereby allowing the core body to pass therethrough. A nozzle for applying a solution of a film precursor as a film on an outer surface, a die part for defining a film thickness of the film by a gap part with the core, and the gap part above the die part A supply part for supplying the solution to the liquid supply part, and a liquid storage part for storing the excess solution in the die part or the supply part, which is scraped by the gap part above the supply part A coating nozzle characterized by comprising:   The coating nozzle according to claim 12, further comprising a masking member that can be attached to and detached from the nozzle for sealing between the nozzles in the die portion.