JP2009261995A - Dip coating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dip coating apparatus capable of forming a stable uniform film, capable of enhancing not only insulating properties or film forming quality but also appearance quality and capable of attaining a coated material of high quality. <P>SOLUTION: In the dip coating apparatus, dip coating and drying treatments are performed in a state in which a coating target 6 is fixed to a holding jig 10 capable of shaking operation in an A direction or rotary operation in a C direction, a combination of rotating and shaking (vibrating) is optionally applied to the holding jig 10 during drying, the stagnation or non-uniform distribution of a coating solution is suppressed by always changing the holding state of the coating target 6, and the coating solution is uniformly adhered to the whole of the coating target 6. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a dipping coating apparatus in which a body to be coated is immersed in a dip tank in which a coating liquid is stored for dipping and drying and curing.

  The dipping coating device has a transfer mechanism that immerses the object to be coated in a dip tank in which the coating liquid is stored and sends it to the next process. The technique to obtain is used.

  FIG. 3 is a diagram for explaining a conventional dipping coating apparatus.

As shown in FIG. 3, the dipping coating apparatus 31 is controlled by the control unit 32 to move the objects to be coated 36a and 36b, which are transferred to the coating position by the transfer chain conveyor 33 and suspended through the hangers 37a and 37b. Then, it is dipped and held in the coating liquid 34 and is subjected to a coating process. After the coating process, the dip tank 35 receives dripping of the excess coating liquid and is applied to the object to be coated. In addition, the conveyor moving speed to the upper part of the dip tank 35, the descent speed until just before the dip coating, the moving speed during immersion, the immersion holding time, the rising speed until exposure to the air after coating, from the exposure to the standby position The set values such as the descent speed and the drop acceptance time are preset according to the material of the coating liquid and the size and shape of the object to be coated.
Such a dipping coating apparatus is disclosed in Patent Document 1, for example.

JP 2001-46935 A

  However, in the conventional dipping coating apparatus shown in FIG. 3, since the object to be coated is always suspended by the hanger with the same holding state, the coating liquid flows down to the lower surface side of the object to be coated after dip coating. In particular, the coating tends to be thin at corners of the object to be coated, and it is necessary to repeat the coating process several times to obtain the desired coating thickness in order to ensure insulation, resulting in an increase in man-hours. There was a problem.

  In addition, since excessive coating liquid drops during the drying process after dip coating, it becomes easy to form icicle-shaped coating lumps and burrs on the lower surface side of the object to be coated, and a uniform coating thickness cannot be obtained. there were.

  Furthermore, for example, when a filler filled with filler is used as the coating liquid and the thermal conductivity is increased, the viscosity is high, and it is difficult to obtain a uniform coating by the conventional method, and the choice of the coating liquid is narrowed. was there.

  The present invention solves the above-mentioned problems, can form a stable uniform film, can improve not only the insulation and film-forming quality but also the appearance quality, and can realize a high-quality coated body. The purpose is to provide a device.

In order to solve these problems, the dipping coating apparatus performs the dip coating process and the drying process in a state where the object to be coated is fixed to a holding jig capable of swinging and rotating, and during the drying process, Applying rotation and swinging (vibration) operations to the holding jig in an appropriate combination, and constantly changing the holding state of the object to be coated, suppresses the accumulation and bias of the coating liquid, and uniformly applies the coating liquid to the entire object to be coated. It is configured so that it can be made.
Further, by performing the dip coating process in a reduced pressure state, preferably in a vacuum state, the coating solution and small bubbles present on the surface of the object to be coated are removed, and a high-density and high-quality coating liquid is applied to the surface of the object to be coated. Higher-quality painting is possible.

  According to the present invention, a dipping coating apparatus for performing a coating process by immersing a body to be coated in a dip tank in which a coating liquid is stored, and then drying the body to be coated to form a coating film, The object to be coated is fixed to a holding jig, and the holding jig is moved up and down in the vertical direction with respect to the dip tank to perform the coating process, and the holding jig includes a swing operation means and a rotation operation means. The dipping coating apparatus is characterized in that the drying process is performed while changing the holding state of the object to be coated by swinging and rotating the holding jig.

  According to the present invention, the holding jig includes a support base including a plate-like body, a first arm, and a second arm, and the first arm is provided on one surface of the support base. The second arm is provided on the other surface, and the first arm is responsible for the vertical movement and swinging motion of the holding jig in the direction perpendicular to the dip tank, and the second arm. A dipping coating apparatus is obtained in which the arm is responsible for holding the object to be coated and rotating the arm.

  As described above, according to the present invention, after the object to be coated is dip-coated, the holding jig is combined with a rotating operation and a swinging operation, and the holding state of the object to be coated is always changed and dried. It is possible to prevent the coating at the corners of the object to flow down and become thin, and to prevent the formation of icicle-like coating lumps and burrs on the lower side, thereby forming a uniform and stable coating film.

  In addition, a heating function is added to the dip tank to control the temperature and viscosity of the coating liquid. For example, by performing dip coating processing in a vacuum device, a high-density, high-quality coating liquid from which small bubbles have been removed can be obtained. It is possible to achieve high-quality coating by infiltrating every surface of the object to be coated, and it is possible to stably dip-paint the object to be coated that is highly filled with filler and has a complicated shape. The film thickness uniformity and film quality can be improved.

  In addition, during the drying process, it is possible to constantly change the holding state of the object to be coated, and it is possible to suppress the amount of extra drops that have accumulated and dropped at a specific location on the lower side of the object to be coated. Since the extra drops are discarded, the material cost can be reduced as a result.

  Embodiments of the present invention will be described with reference to the drawings.

  Each step of the dip coating process and the drying process in the dip coating apparatus of the present invention is omitted because it is based on the conventional technology, but when each process is performed in batch mode, that is, the holding jig to which the object to be coated is fixed is after the dip coating process. Although the case where the drying process is performed by manually moving to the drying device is shown, it is also applicable to an automatic device capable of continuous processing provided with transfer means using a conveyor belt or the like. Therefore, in the following, only the parts and parts related to the holding state of the object to be coated and the structure of the holding jig in the dipping coating apparatus will be shown in a simple and schematic manner, and their indirect or auxiliary parts will be shown. Omitted.

  FIG. 1 is a diagram for explaining a dipping coating apparatus according to the present invention, and shows a perspective view of a state of a body to be coated and a holding jig when the body to be coated is dipped in a coating liquid for coating treatment.

The object to be coated 6 is held in a state of being pressed from the inside by a second arm 3 installed orthogonally to one side of the support base 1 of the holding jig 10, and the second arm 3 of the support base 1. The body 6 to be coated is immersed in the coating liquid 4 in the dip tank 5 by moving the first arm 2 installed perpendicular to the opposite surface in the direction of the arrow A, and the coating is performed by lifting. Here, the holding jig 10 shows a state in which the first arm 2 is suspended from the conveyor belt 9. However, the holding jig 10 is attached to another jig other than the conveyor belt 9 to move the jig up and down. Also good.
Further, the above vertical movement may be performed manually or automatically with a control mechanism such as the amount of moving up and down, the immersion time, and the immersion speed, but is more preferably performed automatically in consideration of workability. .
Further, dipping may be performed while the object to be coated 6 is rotated by driving a motor 8 installed on the support base 1 and applying a rotational motion to the second arm 3 via the belt 7.

In FIG. 1, there is one second arm 3 installed on the support base 1, but a plurality of second arms 3 may be installed, and there is only one object to be coated 6 held by the second arm 3. A plurality of holding portions or anti-slip portions may be provided on the arm 3 so that the arm 3 can be held, and it is preferable to design appropriately according to the size, shape, etc. of the body 6 to be coated.
Furthermore, although one holding jig 10 is shown, a plurality of holding jigs 10 are arranged using another jig on which the holding jig 10 is installed, and the plurality of objects to be coated 6 are simultaneously moved by moving the jig up and down. You may comprise soaking and pulling up.

  It is more preferable that the coating process is performed in a reduced-pressure atmosphere by installing the dip tank 5 and the holding jig 10 to which the object 6 is to be coated in a vacuum apparatus because high-quality coating is possible. It is.

  FIG. 2 is a diagram for explaining the dipping coating apparatus of the present invention, and shows a perspective view of the state of the object to be coated and the holding jig when the object to be coated is pulled up from the coating liquid and dried.

  The holding jig 10 is installed in a drying device (not shown), and is rotated by approximately 90 ° in the direction of arrow B shown in FIG. 1 from the state during the coating process shown in FIG. 1 to move the hook 1a to the conveyor. The motor 8 installed on the support base 1 is positioned above, the second arm 3 to which the object to be coated 6 is fixed is positioned below, and the axial direction of the second arm 3 is the coating liquid. The surface is almost horizontal. However, you may attach to another jigs other than the conveyor belt 9, and in that case, it is preferable to adjust the shape of the hook 1a suitably.

  In the above state, the motor 8 is driven, and the rotating collar 3a of the second arm 3 is rotated in the direction of the arrow C via the belt 7, whereby the object 6 is dried and cured while rotating. Furthermore, by applying the swinging motion of the support base 1 in the direction of arrow A, the coating liquid can be dispersed in the direction perpendicular to the surface of the object to be coated 6 in the rotation direction, and excessive coating liquid is removed. Can also be done.

  In FIG. 2, the motor 8 for rotating the second arm 3 is installed on the support base 1 as a unit integrated with a pulley. However, in order to avoid a heat load, the motor 8 is separated from the support base 1 and outside the drying apparatus. On the other hand, instead of the motor 8, for example, a drum-shaped pulley is installed on the support base 1, and the motor 8 outside the drying device is engaged with one side of the pulley by a belt (not shown), A structure in which the second arm 3 is indirectly rotated by relaying the pulley by engaging the other flange portion of the pulley and the second arm 3 with another belt (not shown). By doing so, the heat resistance in the performance and specifications of the motor 8 can be reduced, which is more practical.

  The material of the support base 1, the first arm 2, and the second arm 3 constituting the holding jig 10 may be any of a heat resistant resin, stainless steel, and a lightweight metal such as aluminum. It is preferable to use a high heat resistance resin effective for durability and weight reduction. Also, the first arm 2 and the second arm 3 may be installed in a direction substantially perpendicular to the plate-like surface of the support base 1 and opposite to each other.

The shape and holding method of the second arm 3 are preferably adjusted as appropriate so that the second arm 3 can be reliably held in consideration of the size and appearance of the object 6 to be coated. In FIG. 1 and FIG. 2, the object to be coated 6 has an annular shape and is pressed and held from the inner diameter side, but may be held with the object to be coated in between. It is preferable to select appropriately according to the shape.
In addition, the shape of the outer peripheral surface of the rotary collar 3a that meshes with the belt 7 is preferably an irregular shape or a sawtooth shape in order to prevent slipping or lateral displacement.

  The coating liquid 4 may be any liquid material for coating an object to be coated, and is not limited to a general insulating material, but may be a conductive material containing metal powder or the like, depending on the purpose of coating. It is preferable to select materials.

It is more preferable that the dip tank 5 stores the coating liquid 4 and has a liquid level control function such as a liquid level sensor (not shown) or a viscosity / temperature control function such as a heater or a stirrer.
Further, it is preferable to appropriately adjust the volume in which the coating liquid 4 is stored so that a plurality of objects to be coated can be immersed simultaneously in view of the efficiency of the painting work.

  The shape of the object to be coated 6 is an annular shape here, but may have any appearance shape.

The belt 7 is preferably made of a material having heat resistance and abrasion resistance capable of withstanding high temperatures during drying and curing of the coating liquid, and having appropriate elasticity, hardness, and low expansion / contraction rate. It is more preferable to select those made of rubber and having high heat-resistant fiber bodies such as polyester fibers embedded in their core bodies.
Further, the cross-sectional shape of the belt 7 is preferably a shape that meshes with each other in order to prevent slippage or lateral displacement with the second arm 3 and the motor 8, for example, a convex-concave shape or a saw-tooth shape. The belt 7 is for transmitting the rotational motion of the motor 8 to the second arm 3. Any method can be used as long as the second arm 3 and the motor 8 are engaged. It is good also as a structure directly meshed like a gear type.

As for the motor 8, it is preferable to select a motor having high heat resistance like the belt and having a torque sufficient to rotate the second arm 3 and the object to be coated 6, but it is installed outside the drying device. In order to avoid the heat load, the heat resistance requirement can be reduced, which is more preferable.
In addition, the shape of the outer peripheral surface in contact with the belt 7 is preferably a shape that meshes with each other to prevent slippage or lateral displacement with the belt 7, for example, an uneven shape or a sawtooth shape.

  The conveyor belt 9 may be a resin material having the same performance as the belt 7 or a metal chain, and is preferably selected in consideration of durability and weight reduction.

  In addition, it is preferable to adjust suitably the raising / lowering speed of a 1st arm and a 2nd arm, a rotation direction, a rotation speed, and the intensity | strength of a rock according to the size of a to-be-coated body, an external appearance shape, and a coating liquid.

  Hereinafter, it explains in full detail using an Example.

  As the support base 1, a phenol resin plate having a shape as shown in FIG. 1 and having a length of 100 mm, a width of 35 mm, and a thickness of 2 mm was used.

  As the first arm 2, a square column made of a baked resin having a length of 50 mm, a length of 15 mm, and a width of 5 mm was embedded in the support base 1 as shown in FIG.

  As the second arm 3, as shown in FIG. 1, a baked resin cylinder having an outer diameter of 5 mm and a length of 70 mm is embedded in the rotary hook 3a, while the rotary hook 3a has an outer diameter of 40 mm and a thickness of 10 mm. The baked resin cylinder was attached to the support base 1.

  As the coating liquid 4, a solid content and a liquid agent were blended in a volume ratio of 6: 4, and a coating liquid having a thermal conductivity of 1 (W / K) was used.

  As the dip tank 5, a storage volume as shown in FIG. 1 having a rectangular shape and a length of 200 mm, a width of 200 mm, and a depth of 100 mm was used, and the coating liquid 4 was filled.

  As the object 6 to be coated, an annular magnetic core having an outer diameter of 30 mm, an inner diameter of 20 mm, and a height of 5 mm was prepared.

  As the belt 7, a material made of silicone rubber and having a polyester fiber embedded in the core was used, and the external dimensions were 6 mm width × 2 mm thickness × circumference length 200 mm. Further, the inner surface of the belt was roughened to prevent slippage between the rotary collar 3a of the second arm 3 and the motor 8.

  As the motor 8, a substantially cylindrical shape having an outer diameter of 40 mm and a thickness of 10 mm as shown in FIG.

  A metal chain was used as the conveyor belt 9.

  Using the above-mentioned members, the dip tank 5 and the holding jig 10 to which the object to be coated 6 is fixed are installed in the vacuum apparatus, and the first arm 2 is moved up and down to move the second arm 3 together with the object to be coated. 6 was immersed in the dip tank 5 for coating treatment. The dip tank 5 was heated at 120 ° C. to adjust the viscosity of the coating liquid 4 and was performed at a vacuum of 1 [torr] or less.

  After the dip coating process, the motor 8 is driven to set the rotation speed of the second arm 3 that fixes the object 6 to be coated via the belt 7 to 12 rotations / minute, and is further installed on the back of the support base 1. The first arm 2 was oscillated in the direction of arrow A and swayed to the object 6 to be coated, and then placed in a high temperature bath and dried and cured at 120 ° C. for 4 hours.

  With the above configuration, a dipping coating apparatus of the present invention using the holding jig shown in FIGS. 1 and 2 was obtained. Further, as a comparative example, the conventional hanging dipping coating apparatus shown in FIG. 3 was prepared using the same material and shape as those of the above-described embodiment of the present invention.

  Samples (n = 10) to be coated by the dipping coating apparatus according to the present invention shown in FIGS. 1 and 2 and the conventional dipping coating apparatus shown in FIG. The film quality state and the dielectric strength were measured, and the comparison results are shown in Table 1. For the film quality state, the cross section of the object to be coated was observed using a magnifying microscope, and the film state such as flowability and film thickness uniformity was observed, and the maximum thickness / minimum thickness value was obtained. In addition, it shows that the value of maximum thickness / minimum thickness is so uniform that it is close to 1. In addition, the dielectric strength is insulated when a copper foil is wound around the surface of the object to be coated and an alternating voltage is applied while gradually increasing the AC voltage between the copper foil and the inner surface of the object to be coated (between the coating film) with an insulation pressure gauge. The breakdown voltage value was measured and taken as the average value of n = 10.

  As shown in Table 1, it can be seen that the dipping coating apparatus according to the present invention significantly improves the uniformity of the coating film as compared with the comparative example. In particular, the coating thickness at the corners is the smallest in the comparative example. However, in the present invention, a minimum of 0.3 mm can be secured, and the unevenness of the coating film due to liquid dripping can be eliminated. It was also found that the dielectric strength was improved by about 30%.

  The embodiments of the present invention have been described above using the embodiments. However, the present invention is not limited to these embodiments, and the present invention is not limited to the scope of the present invention. Included in the invention. That is, various changes and modifications that can be naturally made by those skilled in the art are also included in the present invention.

  The dipping coating apparatus of the present invention enables uniform coating film formation on the object to be coated, and in addition to improving the quality of the coating film, not only cost reduction, but also demands for smaller, thinner and higher performance in the future will be severe. It can greatly contribute to ensuring high insulation and moisture-proof effect in various electronic devices and electronic parts.

The perspective view of the state of a to-be-coated body and a holding jig when the to-be-coated body is immersed in a coating liquid for the coating treatment of the dipping coating apparatus of the present invention. The perspective view of the state of a to-be-coated body and a holding jig when the to-be-coated body is pulled up from a coating liquid and dried by the dipping coating apparatus of the present invention. The figure explaining the conventional dipping coating apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Support stand 1a Hook 2 1st arm 3 2nd arm 3a Rotating collar part 4 and 34 Coating liquid
5, 35 Dip tank 6, 36a, 36b Object to be coated 7 Belt 8 Motor 9 Conveyor belt 10 Holding jig 31 Dipping coating device 32 Control unit 33 Transfer chain conveyors 37a, 37b Hanger

Claims (2)

  A dipping coating apparatus for immersing an object to be coated in a dip tank in which a coating liquid is stored and performing a coating process, and then drying the object to be coated to form a coating film, the object to be coated being a holding jig The coating processing is performed by moving the holding jig up and down in the vertical direction with respect to the dip tank, and the holding jig includes swing operation means and rotation operation means, and swings the holding jig. A dipping coating apparatus, wherein the drying process is performed while changing the holding state of the object to be coated by moving and rotating.   The holding jig includes a support base including a plate-like body, a first arm, and a second arm. The first arm is provided on one surface of the support base, and the first arm is provided on the other surface. Each of the second arms is installed, and the first arm is responsible for vertical movement and swinging movement of the holding jig in the vertical direction with respect to the dip tank, and the second arm is the object to be coated. The dipping coating apparatus according to claim 1, wherein the dipping coating apparatus bears the holding action and the rotation operation.

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