JP2009241056A - Method and apparatus for defoaming coating liquid, and method for manufacturing display member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for defoaming coating liquid which enable direct defoaming treatment without transferring a coating liquid filled into a coating liquid vessel, comprising a pressure-resistant vessel made of hard material and having a flexible inner bag vessel filled with the coating liquid, to another vessel, and to provide a method for manufacturing a display member using the coating liquid defoamed by the defoaming method. <P>SOLUTION: The coating liquid vessel comprises: the pressure-resistant vessel provided with an air inflow channel and made of hard material; the inner bag vessel which provided within the pressure-resistant vessel and is in a flexible bag form, and stores a coating liquid therein; and a discharge guide pipe which discharges and guides the coating liquid in the inner bag vessel to the outside of the pressure-resistant vessel. In the method for defoaming the coating liquid filling in the coating liquid vessel, both following spaces are evacuated: a first space located on the upper part of the coating liquid within the inner bag vessel; and a second space located between the pressure-resistant vessel and the inner bag vessel. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention is used, for example, in the manufacturing field of plasma display front plates, color liquid crystal display color filters, TFT array substrates, optical filters, printed circuit boards, integrated circuits, semiconductors, and the like. The present invention relates to a defoaming method, a defoaming apparatus, and an improvement in a method for producing a display member using a coating liquid defoamed by this defoaming method.

  Generally, in a coating apparatus that has a coating device such as a slit die and coats a substrate to be coated such as a display member, a batch type coating liquid container such as a tank containing a coating liquid is connected to the coating liquid supply apparatus. Then, the coating liquid in the coating liquid container is supplied from the coating liquid supply device to the coating device to perform coating production. If this coating liquid container is made transportable and dedicated to the coating liquid, the coating liquid container shipped after the coating liquid is filled by the coating liquid manufacturer can be used as it is in the coating liquid supply device of the coating apparatus. Can be connected upstream. As a result, the coating liquid inside the coating liquid container can be used immediately without fear of foreign matter contamination or quality deterioration from the outside. In addition, the coating solution container that has become empty after the coating solution is used up is returned to the coating solution manufacturer and reused, but the user of the coating solution container performs maintenance such as cleaning of the coating solution container. Since it is not necessary, there is a benefit that costs can be reduced.

  As such a transportable coating liquid container, a container made of a resin inner bag has recently been used (for example, Patent Document 1).

  This coating solution container accommodates a flexible inner bag container made of resin or the like in a hard pressure-resistant container such as metal and fills the inner bag container with the coating solution. Since the inner bag container has a hermetically sealed structure, the coating liquid sent after being filled by the manufacturer is not exposed to the atmosphere or foreign matter until it is used by the user. Can be kept clean. Also, since the inner bag container is disposable, if the coating solution is used up, the coating solution manufacturer discards the remaining coating solution together with the inner bag container and replaces it with a new inner bag container. Since the liquid can be filled, it is possible to save the trouble of cleaning the inside of the pressure vessel, and further, it is possible to avoid a decrease in cleanliness due to the residue, mixing of foreign matters, and the like.

  A discharge guide pipe extending from the bottom to the outside of the pressure vessel is provided inside the inner bag container. When taking out the coating liquid from this coating liquid container, the joint attached to the lid and the discharge guide pipe communicate with each other. At the same time, since an air inflow path through which air is introduced into the pressure vessel is also provided, the inner bag container is crushed and contracted by pressurizing with air from the air inflow path, and the coating liquid in the inner bag container is It can be sent out via the discharge guide pipe. In addition, this inner bag container delivers the coating liquid without direct contact of the pressurized air with the coating liquid, so that the dissolution of pressurized air into the coating liquid and the mixing of foreign substances from the pressurized air do not occur. There is also.

  Now, in the coating solution filled in the coating solution container, there are usually fine bubbles mixed during filling of the coating solution, or gas is dissolved in the coating solution itself. In particular, the latter may become bubbles with the passage of time, and there may be a narrow gap such as an orifice in the flow path through which the coating liquid flows, or the constant capacity pump that supplies the coating liquid to the applicator suddenly. When a negative pressure state is caused by a simple suction operation, dissolved gas may become bubbles. If the coating solution is coated with a coating device such as a slit die coater in the presence of bubbles in the coating solution, a coating defect such as so-called omission occurs in which the portion with bubbles is not coated, and the quality is significantly impaired. In order to prevent such coating defects, the fine bubbles present in the coating liquid and the dissolved gas are eliminated by a defoaming device for the coating liquid. The defoaming process of the coating liquid may be performed before shipping by the manufacturer in advance, but the process is insufficient, or bubbles are regenerated in the coating liquid due to vibration during transportation after shipping. In some cases, the user side defoaming the coating solution immediately before use is reliable and more effective in eliminating coating defects.

  As a general defoaming device for a coating liquid, there is one that connects a vacuum source to a defoaming container (for example, Patent Document 2). In this case, when the coating liquid in the coating liquid container is put into a dedicated defoaming container and the inside of the container is depressurized with a vacuum source, the coating liquid is defoamed.

  In addition, after opening a part of the coating solution container filled with the coating solution and installing this coating solution container in the defoaming chamber connected to the vacuum source, the defoaming chamber is sealed and the defoaming chamber is depressurized. In some cases, the coating liquid in the coating liquid container is defoamed (for example, Patent Document 3).

  In addition, when the viscosity of the coating solution is high, the coating solution can be defoamed efficiently by stirring the coating solution or applying ultrasonic vibrations in addition to the above-mentioned defoaming container or depressurization chamber. (For example, Patent Document 4).

  On the other hand, in addition to the above-mentioned defoaming means, it is provided in the middle of the pipe connecting the coating solution container and a coating device such as a slit die, and the dissolved bubbles are reduced in pressure through the permeable membrane. There is also a defoaming device that discharges the water (for example, Patent Document 5).

  However, the defoaming means shown in Patent Documents 2 to 4 cannot be directly applied to the coating liquid container that stores the coating liquid in the inner bag container described above. In other words, defoaming treatment can be performed by transferring the coating solution in the inner bag container to a dedicated defoaming container, but if the coating solution in the inner bag container is directly depressurized through the discharge guide pipe, the coating solution is sucked. Degassing is not possible. Further, even if the space between the pressure vessel and the inner bag container is decompressed from the air inflow path, the coating liquid in the inner bag container cannot be defoamed. That said, when the coating liquid is transferred from the coating liquid container having the inner bag container for the defoaming process to the defoaming container, this inner bag container is said to maintain the cleanness and quality of the coating liquid. The excellent features of the coating solution container cannot be utilized. In addition, when the coating liquid defoamed in the defoaming container is further sent to the coating liquid supply device, the coating liquid comes into contact with the pressurized air, etc., and air is again applied to the defoamed coating liquid. Will be dissolved. As described above, in the coating solution container having the inner bag, the defoaming means of Patent Documents 2 to 4 is not preferable.

On the other hand, the defoaming device of Patent Document 5 does not cause a problem due to the defoaming means shown in Patent Documents 2 to 4, but the defoaming performance depends on the coating solution supply speed to the applicator, and in many cases, it is sufficient. Defoaming cannot be performed.
JP-A-2005-298024 (4th column, 1st line to 6th column, 5th line, FIGS. 2 and 8) JP-A-9-206657 (25th column, 1st line to 31st column, 19th line, FIGS. 3 and 4) JP 2000-210929 (third column, first line to fourth column, fourth line, FIG. 4) JP 2002-66431 A (column 4 line 1 to column 7 line 4, FIG. 1) JP-A-2002-126403 (15th column, 1st line to 17th column, 6th line, FIGS. 1 and 2)

  The present invention has been made on the basis of the above-mentioned circumstances, and an object of the present invention is to provide a coating liquid container having a flexible inner bag container in which a coating liquid is filled inside a pressure resistant container made of a hard material. Is to provide a defoaming method and a defoaming device for a coating liquid that can be directly defoamed without transferring the coating liquid in the coating liquid container to another container. Furthermore, the manufacturing method of the member for a display which manufactures the member for a display using the coating liquid defoamed by this defoaming method is provided.

  The above object is achieved by the means described below.

  The defoaming method of the coating liquid according to the present invention includes a pressure-resistant container having an air inflow path and made of a hard material, and a flexible bag that is arranged inside the pressure-resistant container and has flexibility. A defoaming method for a coating liquid filled in a coating liquid container comprising an inner bag container for storing the coating liquid therein and a discharge guide pipe for discharging and guiding the coating liquid in the inner bag container to the outside of the pressure resistant container In the inner bag container, both the first space above the coating liquid and the second space between the pressure-resistant container and the inner bag container are decompressed.

  Here, after starting the pressure reduction from the second space, starting the pressure reduction from the first space, setting the pressure of the second space to be equal to or lower than the pressure of the first space, the first space Pressure reduction from the second space is performed via a discharge guide pipe having a coating liquid inlet in the first space, pressure reduction from the second space is performed via the air inflow path, and the coating liquid container is turned upside down. After the pressure reduction from the first space is performed through the discharge guide pipe, the coating liquid inlet of the discharge guide pipe is in the coating liquid before reversing the top and bottom of the coating liquid container, It is preferable that the coating liquid container is in the first space after being turned upside down.

  The defoaming device for a coating liquid according to the present invention has a pressure vessel made of a hard material with an air inflow path, and is arranged inside the pressure vessel and has a flexible bag shape. Defoaming device for coating liquid filled in a coating liquid container comprising an inner bag container for storing the coating liquid therein and a discharge guide pipe for discharging and guiding the coating liquid in the inner bag container to the outside of the pressure resistant container In the inner bag container, a first pressure reducing means that enables decompression from the first space above the coating solution, and a second decompression that enables decompression from the second space between the pressure container and the inner bag container. And a control unit for controlling the decompression and decompression start timing by the first decompression unit and the second decompression unit, respectively.

  Here, the first pressure reducing means includes a discharge guide pipe having a coating liquid introduction port in a first space serving as a pressure reducing path from the first space, and the second pressure reducing means includes a pressure reducing path from the second space and The first pressure reducing means includes a rotating mechanism that inverts the top and bottom of the coating liquid container to form a first space above the coating liquid in the inner bag container, and a pressure reducing from the first space. Including the discharge guide pipe serving as a path, the second decompression unit including the air inflow path serving as a decompression path from the second space, and the coating liquid inlet of the discharge guide pipe serving as the coating liquid container It is preferable that the liquid is in the coating liquid before being turned upside down and is in the first space after being turned upside down.

  The display member manufacturing method according to the present invention is characterized in that the display member is manufactured using the coating liquid defoamed by the above-described defoaming method of the coating liquid.

  If the defoaming method and defoaming device of the coating liquid according to the present invention are used, the first space above the coating liquid inside the inner bag container, and the pressure-resistant container of the coating liquid container and the flexible inner bag container Since both of the second spaces are depressurized, the coating solution in the inner bag container can be defoamed as it is without being crushed and contracted by the depressurization. In particular, when the discharge guide pipe is short and the coating liquid inlet is in the first space, the defoaming process can be easily performed. Even when the discharge guide pipe communicates with the bottom of the inner bag container, the discharge guide pipe communicates with the first space formed in the upper part of the inner bag container by turning the coating solution container upside down. By depressurizing the first space and the second space from both the air inflow path and the discharge guide pipe outlet, the coating solution in the inner bag container can be defoamed as it is. In any case, since it is not necessary to transfer the coating solution filled in the coating solution container to another container for defoaming, the coating solution is not exposed to the air outside the coating solution container, The coating liquid can be degassed reliably and effectively while maintaining the quality state. Furthermore, by directly defoaming the coating liquid in the coating liquid container having the above structure, the coating liquid is sent out by pressurizing with air from the outside of the inner bag container, and air is again supplied to the defoamed coating liquid. The feature of this coating solution container that it is not dissolved can be fully exhibited.

  According to the method for producing a display member according to the present invention, since the display member is produced using the coating solution defoamed by the above-described excellent defoaming method, the uniformity of the coating film can be reduced at low cost. A high-quality display member having excellent reproducibility and free from coating defects such as bubbles can be produced.

Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic front sectional view of a coating apparatus 100 provided with a defoaming device 1 according to the present invention, and FIG. 2 is a schematic front sectional view showing a state when the coating liquid container 2 is reversed from a normal state. It is. Furthermore, FIG. 3 is a schematic front sectional view of a coating apparatus 200 provided with another defoaming apparatus 201 according to the present invention.

  A defoaming device 1 according to the present invention shown in FIG. 1 includes an application / decompression unit 20 that depressurizes and pressurizes a coating solution container 2 filled with a coating solution 5 via pipes 21A and 21B, and a coating solution container. And a control unit 60 that controls each operation of the rotation mechanism 50.

  Further, the coating apparatus 100 shown in FIG. 1 slits the defoaming apparatus 1, the coating liquid container 2 filled with the coating liquid 5 to be defoamed by the defoaming apparatus 1, and the defoamed coating liquid 5. A coating solution supply device 40 for supplying to the die 63, a slit die 63 for applying the coating solution 5 supplied by the coating solution supply device 40 to the substrate A that is a substrate to be coated, and the substrate A are sucked and held. And a stage 73 that moves in the horizontal direction.

  The coating liquid container 2 is filled with a pressure-resistant container 3 made of a hard material, an inner bag container 4 that is disposed inside the pressure-resistant container 3 and has flexibility, and a bottom portion 13 of the inner bag container 4 as a lowermost part. A discharge guide pipe 6 that takes in the applied coating liquid 5 through a liquid inlet 14 that is a coating liquid introduction port and guides it to the outside of the coating liquid container 2, and a second space between the pressure-resistant container 3 and the inner bag container 4. 8, an air inflow passage 7 communicating with 8, a lid portion 10, and a sealing material 11 inside the lid portion 10. The lid portion 10 of the coating liquid container 2 is provided with a joint 12A for connecting the discharge guide pipe 6 and the pipe 21A of the pressure increasing / decreasing unit 20 of the defoaming apparatus 1, and the pipe 21B of the air inlet path 7 and the pressure increasing / decreasing unit 20 A joint 12B for connection is attached. The discharge guide pipe 6 and the joint 12A, and the air inflow path 7 and the joint 12B are sufficiently sealed and connected. A first space 9 exists above the coating solution 5 filled in the inner bag container 4. The first space 9 and the second space 8 are occupied by a gas such as air.

  Next, the pressure increasing / decreasing unit 20 of the defoaming apparatus 1 includes two switching valves 22A and 22B, a vacuum source 61, and a pressurizing source 62. Further, in the pressure increasing / decreasing unit 20, a pipe 23A, a trap container 24, a pipe 25, an opening / closing valve 26A, a pipe 27A, and a regulating valve 28A are provided on a path from the switching valve 22A to the vacuum source 61 via the pipe 29. And a pipe 23B, an opening / closing valve 26B, a pipe 27B, and an adjustment valve 28B are provided in a path from the switching valve 22B to the vacuum source 61 via the pipe 29, and further, the switching valve 22B. A path from the pressure source 62 to the pressure source 62 is provided with a pipe 30, an opening / closing valve 31, a pipe 32, an adjustment valve 33, and a pipe 34.

  The switching valves 22A and 22B of the pressure increasing / decreasing unit 20 are three-way ball valves. Accordingly, the switching valve 22A can switch the path from the side reaching the coating solution container 2 via the pipe 21A to the pipe 35 side communicating with the slit die 63 and the pipe 23A side communicating with the vacuum source 61. . In the path from the switching valve 22A to the vacuum source 61, the coating liquid 5 remaining in the piping 21A and the switching valve 22A is trapped by the trap container 24 when the coating liquid 5 filled in the coating liquid container 2 is degassed. Can be prevented from entering the vacuum source 61. Further, the opening / closing valve 26A in the same path controls the operation / stop of the pressure reduction to the downstream side (the side opposite to the vacuum source 61), and the inside of the inner bag container 4 of the coating liquid container 2 is controlled by the adjusting valve 28A. The pressure of the first space 9 above the coating liquid 5 is adjusted.

  On the other hand, the switching valve 22B switches the path from the side reaching the coating solution container 2 via the pipe 21B to the pipe 23B side communicating with the vacuum source 61 and the pipe 30 side communicating with the pressurizing source 62. Can do. In the path from the switching valve 22B to the vacuum source 61, the opening / closing valve 26B controls the operation / stop of the decompression of the downstream one, and the regulating valve 28B controls the pressure-resistant container 3 and the inner bag container 4 of the coating liquid container 2. The pressure in the second space 8 between the two is adjusted.

  As described above, the regulators 28A and 28B are preferably vacuum regulators, and the pressure in the first space 9 above the coating liquid 5 in the inner bag container 4 and the pressure container 3 and the inner bag container 4 are The second space 8 in between is preferably depressurized to 50 to 1000 Pa, more preferably 100 to 500 Pa in absolute pressure. The vacuum source 61 preferably uses a dry pump, but other types of pumps such as an oil rotary vacuum pump may be used, and the ultimate vacuum is preferably 1 to 400 Pa.

In the path from the switching valve 22 </ b> B to the pressurizing source 62, the opening / closing valve 31 is used to actuate / stop pressurizing the second space 8 between the pressure-resistant container 3 and the inner bag container 4 in the coating solution container 2. And the pressure in the second space 8 is adjusted by the adjusting valve 33. As described above, the adjustment valve 33 preferably uses a precision regulator for pressurization, and adjusts the pressure of the second space 8 to preferably 0.01 to 1 MPa, more preferably 0.05 to 0.5 MPa. The pressurization source 62, an air and a constant pressure, it is preferable that gas such as N _2.

  Next, the rotation mechanism 50 of the defoaming apparatus 1 includes a base stand 51, a pair of support columns 52A and 52B standing on the base support 51, and shafts 53A and 53B rotatably attached to the pair of support columns 52A and 52B. And gripping portions 54A and 54B of the coating liquid container 2 connected to the shafts 53A and 53B, and a motor 55 that is fixed to the support 52A via the base 56 and drives one shaft 53A. The shafts 53A and 53B and the rotation shaft of the motor 55 are arranged on the same axis. The shaft 53A and the motor 55 are connected by a coupling (not shown), but may be connected via a speed reducer. The coating liquid container 2 and the gripping portions 54A and 54B are fastened by fastening means (not shown). The rotating mechanism 50 reverses the coating solution container 2 up and down by rotating the shafts 53A and 53B, and brings the lid 10 side down in the vertical direction and the bottom 13 of the inner bag container 4 up. The liquid intake port 14 of the discharge guide pipe 6 communicates with the first space 9 formed in the upper part of the coating liquid 5 filled in the inner bag container 4 of the container 2. The pipes 21A and 21B are made of a sufficiently long and bendable material so that the pipes 21A and 21B do not break when the coating solution container 2 rotates.

  The first decompression means for decompressing the first space 9 above the coating liquid 5 in the inner bag container 4 includes a rotating mechanism 50, a pressure-increasing / decreasing unit 20, the discharge guide pipe 6 for the coating liquid container 2, Consists of. The second decompression means for decompressing the second space 8 between the pressure vessel 3 of the coating liquid container 2 and the inner bag container 4 includes the pressurizing / depressurizing unit 20 and the air inflow passage 7 of the coating liquid container 2. Composed.

  The control unit 60 of the defoaming apparatus 1 is electrically connected to the actuators of the switching valves 22A, 22B, the opening / closing valves 26A, 26B, 31 and the regulating valves 28A, 28B, 33, and is input in advance. By sending control signals according to control parameters and programs to each part, switching of piping path, adjustment of pressure during pressure reduction or pressurization, action / stop of pressure reduction / pressurization, and adjustment of action start / end timing Etc. are controlled. The control unit 60 is also electrically connected to a motor 55 of the rotation mechanism 50, and can drive / stop the motor 55 at an arbitrary timing.

  Furthermore, a coating liquid supply device 40 is connected to the switching valve 22A via a pipe 35, an opening / closing valve 36, and a pipe 41. The coating liquid supply device 40 is connected to the suction valve 42 connected to the pipe 41, the constant capacity pump 44 communicated with the suction valve 42 via the pipe 43, and the constant capacity pump 44 via the pipe 45. It comprises a discharge valve 46 and a pipe 47 connecting the slit die 63 and the discharge valve 46. The constant capacity pump 44 may be any liquid supply means that operates intermittently to ensure constant capacity. For example, a syringe pump, a gear pump, a screw pump, a diaphragm pump, a bellophram pump, etc. Is preferably applied. Further, instead of the constant capacity pump 44, a constant pressure is applied to the second space 8 between the pressure-resistant container 3 of the coating liquid container 2 and the inner bag container 4 by air, nitrogen gas, etc., and the inner bag container is interposed. The coating liquid 5 may be supplied to the slit die 63 by indirect pressure supply. The suction valve 42 and the discharge valve 46 can arbitrarily carry out / shut off the coating liquid 5 subjected to the defoaming process.

  The slit die 63 can uniformly discharge the coating liquid 5 from the coating liquid discharge port 64 that is an outlet of the slit by allowing the coating liquid 5 to pass through a slit formed between a pair of lips facing each other with a gap therebetween. Is. The material of the slit die 63 is not particularly limited, but ceramic materials or those obtained by applying surface treatment to these materials may be used in addition to metal materials such as stainless steel and cemented carbide. Stainless steel is particularly suitable because it has chemical resistance and is inexpensive. The slit die 63 can reciprocate freely in the vertical direction by a lifting mechanism (not shown). The coating liquid 5 discharged from the slit die 63 is also applied to the substrate A that is sucked and held on the stage 73 that is movable in the horizontal direction by a driving source (not shown).

  In the coating apparatus 100 shown in FIG. 1, the inner bag container 4 is crushed and contracted by pressurizing the second space 8 between the pressure resistant container 3 and the inner bag container 4 by the pressure source 62. The coating solution 5 filled in the inner bag container 4 passes through the discharge guide pipe 6, the pipe 21 </ b> A, the switching valve 22 </ b> A, the pipe 35, the opening / closing valve 36, the pipe 41, the suction valve 42 and the pipe 43, and then to the constant capacity pump 44. Supplied. At this time, the defoamed coating liquid 5 is pressurized with a gas such as air through the inner bag container 4 and is not directly pressurized, so that the gas such as air is not dissolved again in the coating liquid 5. . Then, the coating liquid 5 is sent from the constant volume pump 44 to the slit die 63 at a constant supply speed, and coating is performed. In addition, the piping connecting each component uses, for example, a flexible plastic hose such as a fluorine resin hose, a silicon blade hose, a polyethylene hose, a polypropylene hose, or a metal pipe. May be.

  Next, the defoaming method of the coating liquid 5 in the coating liquid container 2 using the defoaming apparatus 1 of the present invention described above will be described in detail.

  First, as an initial state, the switching valve 22A of the pressure increasing / decreasing unit 20 is connected to the piping 21A and the piping 35, the switching valve 22B is connected to the piping 21B and the piping 30, and the on-off valves 26A, 26B, and 31 are all closed. It is in the state. Next, the coating solution container 2 is fastened and fixed to the gripping portions 54A and 54B of the rotating mechanism 50 by fastening parts (not shown). The amount of the coating liquid 5 filled in the inner bag container 4 in the coating liquid container 2 at the time of defoaming is preferably 50 to 95%, more preferably 80 to 90% with respect to the volume of the inner bag container 4. %. If it is smaller than this range, the consumption cycle until the coating liquid 5 in the inner bag container 4 in use is used up and becomes empty is shortened, so the number of times of replacement and defoaming of the coating liquid container 2 increases and the production efficiency decreases. End up. On the other hand, if it is larger than this range, the first space 9 above the coating solution 5 for defoaming the coating solution 5 in the inner bag container 4 cannot be sufficiently secured, so that the defoaming processing efficiency is lowered and is serious. In some cases, the defoaming process becomes impossible. Subsequently, the pipes 21A and 21B of the pressure increasing / decreasing unit 20 are connected to the joints 12A and 12B of the coating solution container 2, respectively. Next, the control unit 60 starts the motor 55 of the rotation mechanism 50, and the coating liquid container 2 is turned upside down so as to be in the state shown in FIG. 2 (a) to FIG. 2 (b) and discharged. The liquid intake port 14 of the guide pipe 6 is communicated with the first space 9 above the coating liquid 5 in the inner bag container 4. At this time, the rotation speed for reversing the coating liquid container 2 is preferably low so that the coating liquid 5 filled in the inner bag container 4 does not foam due to impact during rotation.

  Next, the control unit 60 operates the switching valve 22A so that the piping 21A and the piping 23A communicate with each other, and the switching valve 22B operates so that the piping 21B and the piping 23B communicate with each other. After starting the vacuum source 61, the first space 9 above the coating liquid 5 in the inner bag container 4 and the second space 8 between the pressure-resistant container 3 of the coating liquid container 2 and the inner bag container 4 are provided. The control valves 60A and 28B are adjusted by the control unit 60 so that the pressure of the pressure becomes a predetermined value. Here, the pressure in the first space 9 above the coating liquid 5 inside the inner bag container 4 of the coating liquid container 2 is Pa, and the second space 8 between the pressure-resistant container 3 of the coating liquid container 2 and the inner bag container 4 is. When Pb is Pb, Pa ≧ Pb is always satisfied. By setting such a pressure relationship, it is possible to prevent the inner bag container 4 from being crushed and contracted during defoaming due to a pressure difference between the inside and outside of the inner bag container 4. After the above adjustment is completed, the control unit 60 opens the on-off valves 26A and 26B. The on-off valves 26A and 26B may be opened at the same time. However, it is preferable to control the on-off valve 26B to be opened first and then the on-off valve 26A to be opened. By opening the opening / closing valves 26B and 26A in the order, the pressure is always reduced first from the second space 8, so that the inner bag container 4 expands toward the pressure vessel 3 and the inner bag container 4 is crushed. Then, the coating liquid 5 is decompressed and degassed by depressurizing the first space 9 through the liquid inlet 14 of the discharge guide pipe 6 without the coating liquid 5 being sent out of the coating liquid container 2. Can do.

  The pressure Pa in the first space 9 and the pressure Pb in the second space 8 are preferably 50 to 1000 Pa, more preferably 100 to 500 Pa, although depending on the value of the vapor pressure of the coating solution 5. If it is smaller than this, the solvent of the coating solution 5 evaporates and the solid content concentration changes (increases), and if it is larger than this, the defoaming treatment cannot be performed sufficiently, which is not preferable.

  After the defoaming process is completed after opening the opening / closing valve 26A, the control unit 60 preferably closes the opening / closing valve 26A first and then closes the opening / closing valve 26B. However, the opening / closing valves 26A and 26B are simultaneously closed. It may be in a closed state. By closing the opening / closing valves 26A and 26B in the order, the pressure reduction operation remains in the second space 8, and the inner bag container 4 maintains the expanded state toward the pressure vessel 3 side. It is possible to reliably prevent the coating liquid 5 filled in the inner bag container 4 from being sent out of the coating liquid container 2 by being crushed and contracted. As described above, the vacuum source 61 is stopped after the opening / closing valves 26A and 26B are closed and the defoaming process of the coating liquid 5 is completed. The defoaming treatment time is preferably 1 to 120 seconds, more preferably 2 to 60 seconds. If it is shorter than this, the defoaming treatment cannot be performed sufficiently, and if it is longer than this, the solvent of the coating solution 5 evaporates and the solid content concentration changes (increases), which is not preferable. Subsequently, the control unit 60 activates the motor 55 of the rotating mechanism 50, and the coating liquid container 2 is turned upside down so that the state shown in FIG. 2B to FIG. Return to. Also at this time, as before the start of defoaming, the rotation speed for reversing the coating liquid container 2 is to prevent refoaming due to impact during rotation on the defoamed coating liquid 5 filled in the inner bag container 4. It is preferable to carry out at low speed. Finally, the decompressed piping path is opened to the atmosphere by a leak valve (not shown) provided in the vacuum source 61.

  Next, with reference to FIG. 3, the coating apparatus 200 provided with the defoaming apparatus 201 which is another embodiment of this invention is shown. The coating apparatus 200 has the same configuration as the coating apparatus 100 except that the defoaming apparatus 1 is replaced with the defoaming apparatus 201 and the coating liquid container 2 is replaced with the coating liquid container 202 in the above-described coating apparatus 100. The defoaming device 201 has the same configuration as the defoaming device 1 except that the rotating mechanism 50 is removed from the defoaming device 1. That is, the defoaming apparatus 201 and the pressure-increasing / decreasing unit 20 are the same. The coating liquid container 202 is the same as the coating liquid container 2 except that the discharge guide pipe 6 of the coating liquid container 2 is replaced with a short discharge guide pipe 206. In the initial connection state in which the coating liquid container 202 is installed and first connected to the defoaming device 201 (the pressure increasing / decreasing unit 20), the liquid inlet 214 serving as the coating liquid inlet of the discharge guide pipe 206 is It is above the liquid level and is not in contact with the coating liquid 5 but in contact with the air in the first space 9. When pressurized air is supplied to the second space 8 to pressurize and the inner bag container 4 is crushed and deformed from the outside, the coating liquid 5 moves upward and reaches the liquid inlet 214 of the discharge guide pipe 206. If the pressurized air is further supplied to the second space 8, the inner bag container 4 is further deformed, so that the extruded coating liquid 5 rises from the liquid intake port 214 through the discharge guide pipe 206 to the inside of the pipe 21 </ b> A. The flow finally reaches the constant capacity pump 44.

  Next, a method for defoaming the coating liquid 5 in the coating liquid container 202 using the defoaming apparatus 201 will be described. First, the inner bag container 4 in the coating liquid container 202 is connected in the initial connection state, that is, in the state where the pipes 21A and 21B of the defoaming device 201 (the pressure increasing / decreasing unit 20) are connected to the joints 12A and 12B of the new coating liquid container 202, respectively. Since the liquid inlet 214 of the discharge guide pipe 206 in the inside is already in the first space 9 above the coating liquid 5, a suction force from the vacuum source 61 of the pressure increasing / decreasing unit 20 is added to the discharge guide pipe 206. Even if the pressure is reduced, the coating liquid 5 is not sucked and only the air in the first space 9 is sucked. Therefore, defoaming of the coating liquid 5 in the coating liquid container 202 can be started immediately in the initial state. That is, in the defoaming method of the coating liquid 5 in the coating liquid container 2 using the defoaming apparatus 1 described above, the defoaming method is exactly the same except that the upside down operation of the coating liquid container 2 by the rotating mechanism 50 is omitted. To implement. In this defoaming method, since the decompression of the second space 8 is started at the pressure Pb and the decompression of the first space 9 is performed at the pressure Pa, the inner bag container 4 is stably crushed without being crushed. Defoaming of the coating liquid 5 inside becomes possible. In the coating apparatus 200, the defoaming apparatus 201 can defoam the coating liquid 5 without performing the work of turning the coating liquid container 202 upside down. Therefore, the time required for defoaming the coating liquid 5 can be shortened. it can. In addition, there is also an effect that there is no concern that the coating liquid 5 filled in the inner bag container 4 foams due to an impact when the coating liquid container 202 rotates.

  Next, a coating method in which the coating liquid 5 defoamed by the defoaming apparatus 1 of the present invention is coated by the coating apparatus 100 will be described. It is assumed that a syringe pump is used as the constant capacity pump 44.

  First, after completing the above-described series of defoaming operations, the control unit 60 closes the opening / closing valve 36, and then connects the switching valve 22A to the piping 21A and the piping 35. The switching valve 22B is operated so that the pipe 21B and the pipe 30 communicate with each other. Next, the pressure for pressurizing the second space 8 is appropriately adjusted by the adjusting valve 33 connected to the pressurizing source 62 via the pipe 34. The pressure in the second space 8 is preferably 0.01 to 1 MPa, more preferably 0.05 to 0.5 MPa. When the opening / closing valve 31 is opened by the control unit 60, the second space 8 is pressurized, and further, the opening / closing valve 36 is opened, so that the inner bag container 4 contracts and the inner bag container 4 is removed. The foamed coating liquid 5 is delivered to the coating liquid supply device 40. Then, the suction valve 42 and the discharge valve 46 are opened, the coating liquid 5 is sent to the constant capacity pump 44 and the slit die 63, and the coating liquid container 2 to the slit die 63 are filled with the coating liquid 5, When the air inside is discharged, the suction valve 42 is closed. At this time, the constant volume pump 44, which is a syringe pump, is in a state where the coating liquid 5 is already filled in the syringe and the discharge valve 46 is open, so that a predetermined amount of the coating liquid 5 is always supplied to the slit die 63. It can be done.

  Next, lift pins (not shown) are raised on the upper surface of the stage 73, and the substrate A is placed on the lift pins from the loader (not shown). Subsequently, the lift pins are lowered to place the substrate A on the surface of the stage 73 and simultaneously hold it by suction. Then, the stage 73 starts to move at a predetermined coating speed, and is stopped when the coating start portion of the substrate A comes directly below the coating liquid discharge port 64 of the slit die 63. Subsequently, a lifting device (not shown) is driven to bring the coating liquid discharge port 64 of the slit die 63 close to the position separated from the substrate A by a predetermined clearance. Then, the constant volume pump 44 (syringe pump) is driven, the coating liquid 5 is discharged from the slit die 63 toward the substrate A, the bead B is formed between the substrate A and the stage 73 is driven at a predetermined speed. Beginning, a coating film C is formed on the substrate A. When the coating end portion of the substrate A comes to the position of the coating liquid discharge port 64 of the slit die 63, the constant volume pump 44 (syringe pump) is stopped to stop the supply of the coating liquid 5, and then the slit die 63 is raised. . As a result, the bead B formed between the substrate A and the slit die 63 is cut off, and the application is completed.

  During these operations, the stage 73 continues to move, stops when it reaches the end point position, lifts the substrate A by lifting a lift pin (not shown) after releasing the suction holding of the substrate A. At this time, the lower surface of the substrate A is held by an unloader (not shown), and the substrate A is transported to the next step. When the substrate A is delivered to the unloader, the stage 73 lowers the lift pins and returns to the origin position.

  Subsequently, the discharge valve 46 is closed, the suction valve 42 is opened, and the application liquid 5 is supplied from the application liquid container 2 into the syringe of the syringe pump that is the constant volume pump 44 and filled. After the filling is completed, the suction valve 42 is closed, the discharge valve 46 is opened, the next substrate A is waited for, and the same operation is repeated. Before the slit die 63 comes close to the coating start portion of the substrate A, it is preferable to clean or initialize the periphery of the coating liquid discharge port 64 of the slit die 63.

  The defoaming device 1 configured as described above defoams the coating solution 5 in the coating solution container 2, and the defoamed coating solution 5 is transferred to the coating solution supply device 40 without dissolving the gas again. Since it is applied to the substrate A by the slit die 63 after being supplied, it is possible to eliminate the occurrence of coating defects such as pinholes due to bubbles on the coating film surface, and the characteristics of the coating liquid container 2 Since there is no mixing of a foreign substance and no change or deterioration in the quality of the coating liquid 5, a high-quality coating film surface can be obtained.

  Next, in another coating apparatus 200 according to the present invention, there is a coating method in which the coating liquid 5 defoamed by the defoaming apparatus 201 is coated. The coating apparatus except that the coating liquid container 2 is replaced with the coating liquid container 202. 100 is exactly the same as the coating method of coating. Since the coating liquid 5 defoamed by the defoaming device 201 is also applied to the substrate A without the gas being dissolved by the coating device 200, a coating film surface free from coating defects due to bubbles can be obtained. At the same time, a high-quality coating film surface free from foreign matters and quality deterioration of the coating solution 5 can be obtained.

  The viscosity of the coating solution 5 to which the present invention can be applied is preferably 1 to 100 mPaS, more preferably 2 to 50 mPaS, and its properties are preferably Newtonian, but it is also applicable to the coating solution 5 having thixotropy. it can. In particular, it is effective when applying a coating solution 5 using a solvent having high volatility, for example, propylene glycol monomethyl ether acetate, butyl acetate, ethyl lactate or the like. Specific examples of the coating solution 5 that can be applied include a positive resist solution for forming an ITO transparent electrode pattern on a front plate for plasma displays, a TFT for forming TFTs for liquid crystal displays, a black matrix for color filters, and a coating for forming RGB color pixels. In addition to liquids, there are overcoat materials, column forming materials, and the like. As the substrate A, in addition to glass, a metal plate such as aluminum, a ceramic plate, a resin plate, a silicon wafer, or the like may be used. Moreover, as application conditions to be used, the clearance that is the distance between the coating liquid discharge port 64 of the substrate A and the slit die 63 is 10 to 200 μm, more preferably 50 to 100 μm, the application speed is 0.1 to 30 m / min, More preferably, it is 1-20 m / min, the gap | interval of the slit part of the slit die 63 is 50-1000 micrometers, More preferably, it is 80-200 micrometers, The thickness of the coating film C is 1-50 micrometers in a wet state, More preferably, it is 2-20 micrometers is there.

  Furthermore, the defoaming apparatus 1 and defoaming apparatus 201 of the present invention also apply to the coating liquid 5 applied to a long web (long substrate to be coated) such as a film, a metal sheet, a metal foil, or paper. A defoaming process may be applied.

  Next, the present invention will be further described using specific examples.

Example 1:
The coating apparatus 100 shown in FIG. 1 was used. A coating liquid 5 having a viscosity of 7.5 mPa · s and a solid content concentration of 16% and being a positive resist liquid for pattern formation of an ITO transparent electrode for a front plate of a plasma display is placed in a stainless pressure resistant container 3. The inner bag container 4 formed into a bag shape with a 1 mm thick polyethylene film was filled with 16 L. The inner bag container 4 could be filled with a maximum of 19 L of the coating liquid 5. The discharge guide pipe 6 in the inner bag container 4 was a fluororesin tube having an inner diameter of 5 mm, an outer diameter of 8 mm, and a length of 650 mm, and the shape of the liquid inlet 14 was a substantially circular shape with a diameter of 4 mm. In order to connect the first space 9 above the coating liquid 5 in the inner bag container 4 and the liquid intake port 14 of the discharge guide pipe 6, the coating liquid container 2 is moved at a rotational speed of 2 rpm by the rotation mechanism 50 of the defoaming device 1. Inverted. As the vacuum source 61, a diaphragm type dry vacuum pump having an ultimate pressure of 260 Pa and an exhaust speed of 120 L / min was used. The control unit 60 adjusts the adjustment valve 28A so that the pressure in the first space 9 above the coating liquid 5 in the inner bag container 4 is 290 Pa. Similarly, the pressure-resistant container 3 and inner bag of the coating liquid container 2 are adjusted. The adjustment valve 28B was adjusted so that the pressure in the second space 8 between the container 4 and the container 4 was 270 Pa. Next, two seconds after the control unit 60 opens the opening / closing valve 26B communicating with the second space 8, the opening / closing valve 26A communicating with the first space 9 is opened, and the degassing process of the coating liquid 5 is started. did. Sixty seconds after the opening / closing valve 26A was opened, the control unit 60 first closed the opening / closing valve 26A, and two seconds later, the opening / closing valve 26B was closed, and the vacuum degassing process was completed.

  Next, it apply | coated with the coating device 100 using the coating liquid 5 which finished the said defoaming process. A slit die 63 having a slit gap of 100 μm and a longitudinal length of 554 mm was used. Since the coating liquid 5 is sent from the coating liquid container 2 to the coating liquid supply device 40 via the discharge guide pipe 6, the pressure of the air supplied from the pressure source 62 to the first space 9 is 0.05 MPa. Thus, the adjustment valve 33 was adjusted by the control unit 60. Then, on a cleaned glass substrate of 590 mm (width) × 964 mm (length) × 2.8 mm (thickness), the coating thickness when wet is 12 μm, the coating speed is 2 m / min, and the coating liquid discharge port 64 of the slit die 63 is used. The coating liquid 5 was applied at a clearance of 150 μm between the glass substrate and the glass substrate to form a coating film having a coating width of 554 mm and a coating length of 964 mm. And the glass substrate A after application | coating was taken out with the transfer machine from the stage 73, and it put into the drying furnace using a hotplate after drying for 60 seconds at normal temperature, and dried for 10 minutes at 100 degreeC. After drying, the coating quality and the state of the film surface were inspected. As a result, there were no pinholes or defects due to bubbles over the entire coating film surface, and the coating quality and film surface condition were satisfactory. Subsequently, the same coating was performed continuously on 100 glass substrates using the same defoaming coating solution 5, but there were no defects such as pinholes, and the coating quality and film surface were good. .

Example 2:
In the first embodiment, the defoaming apparatus 1 is replaced with the defoaming apparatus 201, the coating liquid container 2 is replaced with the coating liquid container 202, the discharge guide pipe 6 is replaced with the discharge guide pipe 206, and the coating apparatus 100 is replaced with the coating apparatus 200. Except for omitting the reversal operation, the defoaming treatment of the coating solution 5, the application to the glass substrate and the drying were performed. The discharge guide pipe 206 in the coating liquid container 202 is a fluororesin tube having an inner diameter of 5 mm, an outer diameter of 8 mm, and a length of 70 mm, and the shape of the liquid inlet 214 is a substantially circular shape having a diameter of 4 mm. It was. In addition, the liquid inlet 214 was above the coating liquid 5 and in contact with the first space 9 in the initial connection state in which the coating liquid container 202 was connected to the defoaming device 201 (the pressure increasing / decreasing unit 20). After drying, the coating quality and the film surface state were inspected. As a result, there were no pinholes or foreign matter defects caused by bubbles over the entire coating film surface, and the coating quality and film surface state were satisfactory. Subsequently, the same coating was performed on 200 glass substrates using the same defoaming coating solution 5, but there were no defects such as pinholes, and the coating quality and film surface were good. .

Comparative example:
Except that the coating solution 5 was not defoamed by the defoaming apparatus 1, a coating film was formed on the glass substrate and dried in the same manner as in Example 1, and the coating quality and the state of the film surface were inspected. As a result, 2 to 3 pinholes considered to be caused by bubbles having a substantially circular shape and a diameter of 1 mm or less were confirmed per 100 mm square area on the coating film surface.

  This invention is applied to the surface of a substrate to be coated such as a glass substrate in the manufacturing field of, for example, a front plate of a plasma display, a color filter for a color liquid crystal display, an array substrate for TFT, an optical filter, a printed circuit board, an integrated circuit, or a semiconductor. When forming a coating film while discharging a liquid, it can be used to manufacture a high-quality product that does not cause coating defects or film thickness defects due to foreign matters or bubbles.

It is a schematic front sectional drawing of the coating device 100 provided with the defoaming apparatus 1 which concerns on this invention. FIG. 3 is a schematic front cross-sectional view showing a state when the coating liquid container 2 is reversed from a normal state. It is a schematic front sectional drawing of the coating device 200 provided with another defoaming apparatus 201 which concerns on this invention.

Explanation of symbols

1: Defoaming device 2: Coating liquid container 3: Pressure resistant container 4: Inner bag container 5: Coating liquid 6: Discharge guide pipe 7: Air inflow path 8: Second space 9: First space 10: Lid 11: Seal Materials 12A, 12B: Joint 13: Bottom portion 14 of inner bag container 4: Liquid inlet 20: Pressure-reducing unit 21A, 21B: Pipe 22A, 22B: Switching valve 23A, 23B: Pipe 24: Trap container 25: Pipes 26A, 26B : Open / close valves 27A, 27B: Pipes 28A, 28B: Adjustment valve 29: Pipe 30: Pipe 31: Open / close valve 32: Pipe 33: Adjustment valve 34: Pipe 35: Pipe 36: Open / close valve 40: Coating liquid supply device 41: Pipe 42: Suction valve 43: Pipe 44: Constant capacity pump 45: Pipe 46: Discharge valve 47: Pipe 50: Rotating mechanism 51: Base bases 52A, 52B: Support columns 53A, 53B: Shafts 54A, 54B Gripping part 55: Motor 56: Base 60: Control unit 61: Vacuum source 62: Pressurizing source 63: Slit die 64: Coating liquid discharge port 73: Stage 100: Coating device 200: Coating device 201: Defoaming device 202: Coating Liquid container 206: Discharge guide pipe 214: Liquid inlet A: Substrate (substrate to be coated)
B: Bead C: Coating film

Claims (11)

A pressure-resistant container comprising an air inflow path and made of a hard material, and an inner bag container that is arranged inside the pressure-resistant container and is configured in a flexible bag shape and stores the coating liquid therein, A defoaming method for a coating liquid filled in a coating liquid container constituted by a discharge guide pipe for discharging and guiding the coating liquid in the inner bag container to the outside of the pressure resistant container, the coating liquid being contained in the inner bag container The defoaming method of the coating liquid, wherein both the first space at the top of the container and the second space between the pressure-resistant container and the inner bag container are depressurized. The defoaming method for a coating liquid according to claim 1, wherein the pressure reduction from the first space is started after the pressure reduction is started from the second space. The method of defoaming a coating solution according to claim 1 or 2, wherein the pressure in the second space is made equal to or lower than the pressure in the first space. The pressure reduction from the first space is performed through a discharge guide pipe having a coating liquid inlet in the first space, and the pressure reduction from the second space is performed through the air inflow path. The defoaming method of the coating liquid in any one of 1-3. The defoaming method for a coating liquid according to any one of claims 1 to 3, wherein after the top and bottom of the coating liquid container are turned upside down, pressure reduction from the first space is performed via the discharge guide pipe. . The coating liquid introduction port of the discharge guide pipe is in the coating liquid before the top and bottom of the coating liquid container is reversed, and is in the first space after the top and bottom of the coating liquid container is reversed. The defoaming method of the coating liquid according to claim 5. A pressure-resistant container comprising an air inflow path and made of a hard material, and an inner bag container that is arranged inside the pressure-resistant container and is configured in a flexible bag shape and stores the coating liquid therein, A defoaming device for a coating liquid filled in a coating liquid container constituted by a discharge guide pipe for discharging and guiding the coating liquid in the inner bag container to the outside of the pressure resistant container, wherein the coating liquid is contained in the inner bag container. First decompression means capable of decompressing from the first space above the second, second decompression means capable of decompressing from the second space between the pressure vessel and the inner bag container, first decompression means and second A defoaming device for a coating liquid, comprising: a control unit that controls decompression by the decompression means and decompression start timing. The first pressure reducing means includes a discharge guide pipe having a coating liquid introduction port in a first space serving as a pressure reducing path from the first space, and the second pressure reducing means includes the air serving as a pressure reducing path from the second space. The apparatus for defoaming a coating liquid according to claim 7, further comprising an inflow path. The first pressure reducing means includes a rotation mechanism that inverts the top and bottom of the coating liquid container to form a first space above the coating liquid in the inner bag container, and the discharge guide pipe that serves as a pressure reducing path from the first space. The defoaming device for a coating liquid according to claim 7, wherein the second decompression means includes the air inflow passage serving as a decompression path from the second space. The discharge guide pipe has a coating solution inlet in the coating solution before the coating solution container is turned upside down and in the first space after the coating solution container is turned upside down. The defoaming device for a coating solution according to claim 9, wherein the device is a defoaming device. A display member is manufactured using the coating liquid defoamed by the coating liquid defoaming method according to claim 1, wherein the display member is manufactured.

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