JP2006102608A - Defoaming method and apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for defoaming a liquid to be treated, permitting ready and reliable formation of a good coated surface, independent of the type of the liquid and inclusion conditions of bubbles, by detecting the defoamed conditions of the liquid during defoaming treatment. <P>SOLUTION: A concentration meter 25 for dissolved oxygen, a density meter 26 and a bubble detector 27 based on a near IR transmitted/diffused light system are arranged in a closed container 3 so as to measure the concentration of dissolved oxygen in a liquid 2 under defoaming treatment, the specific gravity of the liquid and the output of the transmitted/diffused light in the container 3. The measurements are judged whether to reach predetermined threshold values. When the measurements reach the values, the apparatus stops stirring of the liquid 2 with an external blade 4 for promotion of defoaming and an internal blade 5 for blending stirring. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention provides a defoaming treatment liquid during defoaming treatment when defoaming bubbles contained in the treatment liquid of the pressure sensitive adhesive as a pre-process applied to the pressure sensitive adhesive tape in a production process of an adhesive tape having an adhesive layer. The present invention relates to a defoaming method and a defoaming device for automatically controlling pressure applied to a processing liquid and stirring means so as to detect a state and shift to a predetermined set defoaming state.

In general, liquids with high viscosity such as synthetic resins used for pressure-sensitive adhesives such as pressure-sensitive adhesive tapes often contain bubbles in the production process, and the bubbles once contained are difficult to escape due to their high viscosity. . When a liquid containing bubbles is applied to an object, uneven coating such as pinholes, streaks, craters, and bubble peeling occurs on the application surface.
Here, various methods have been proposed as defoaming methods for removing bubbles from the liquid. In particular, a defoaming method called a depressurization method expands bubbles in a liquid by placing the liquid under reduced pressure. This is a method for promoting the generation of bubbles.
As a defoaming apparatus for performing the depressurization method, for example, in Japanese Patent Application Laid-Open No. 2003-103110, after introducing a liquid agent into a depressurization tank, the liquid is stirred under reduced pressure to expand and float the bubbles in the liquid. A defoaming device is described in which bubbles are detected by a sensor, and on the basis of a signal from the sensor, a pressure air is jetted from the air nozzle provided at the upper part of the tank toward the rising bubbles to destroy the bubbles. .
Japanese Patent Laying-Open No. 2003-103110 (pages 4 to 5, FIG. 1)

However, in the conventional defoaming apparatus and the defoaming method described in Patent Document 1 described above, it is possible to efficiently defoam the treatment liquid. It was not possible to confirm whether or not the treatment liquid was in the required defoamed state. That is, depending on the type of treatment liquid and the state of air bubble mixing, the time required for defoaming is estimated from the user's experience and the like, and defoaming is performed. Here, if the time for the defoaming treatment is insufficient, coating unevenness such as pinholes, streaks, craters, foam baldness, etc. occurs on the coating surface. On the other hand, if the defoaming treatment is excessive, the work efficiency is increased. Will get worse.
Furthermore, the processing liquid for performing the defoaming treatment is not limited to one type. For example, there are many types such as an acrylic polymer type, an acrylic emulsion type, a UV curing type, and the optimum defoaming time depending on the type. Is different. In addition, even in the case of the same type of processing liquid, the amount of bubbles mixed in may be different, and it is difficult to uniquely determine the time. Therefore, in order to derive the optimum defoaming processing time, many experiments are required, and time and money burdens are large.
In addition, since quality assurance is not performed within the defoaming process, if a bubble defect is detected in the subsequent inspection process, the production line is stopped, whether it is a problem on the defoaming operation side or a problem on the coating operation side. It was necessary to investigate and readjust.

  The present invention has been made to solve the above-described conventional problems, and by detecting the defoaming state of the processing liquid and automatically controlling the pressure applied to the stirring means and the processing liquid, the type of processing liquid and bubbles It is an object of the present invention to provide a defoaming method and a defoaming device capable of performing appropriate defoaming of a treatment liquid in a short time without being influenced by the state of contamination of the liquid.

  In order to achieve the above object, the defoaming method according to claim 1 of the present application is arranged such that the processing liquid in which bubbles are mixed is placed in a state where the pressure is reduced to a predetermined pressure and is stirred by a stirring means, whereby the processing liquid is separated from the bubbles. In the defoaming method for separating into a liquid, the pressure and / or the defoaming state of the treatment liquid is detected and the detected defoaming state shifts to a preset predetermined defoaming state. The stirring means is automatically controlled.

  The defoaming method according to claim 2 is characterized in that, in the defoaming method according to claim 1, the pressure and / or the stirring means is controlled based on the detected defoaming state of the processing liquid. And

  The defoaming method according to claim 3 is the defoaming method according to claim 1 or 2, wherein the defoamed state detected is the dissolved oxygen concentration, density specific gravity and transmitted scattered light of the treatment liquid. It is determined based on any value or all values of the output.

  Further, the defoaming apparatus according to claim 4 includes: a sealed container that encloses the processing liquid; a decompression unit that depressurizes the inside of the sealed container; and an agitation unit that stirs the processing liquid enclosed in the sealed container. In the defoaming apparatus, the setting means for setting a predetermined defoaming state, the detection means for detecting the defoaming state of the processing liquid, and the defoaming state detected by the detection means are set by the setting means. And an automatic control means for automatically controlling the pressure reducing means and / or the stirring means so as to shift to a set defoaming state.

  The defoaming apparatus according to claim 5 is the defoaming apparatus according to claim 4, wherein the automatic control means controls the decompression means and / or the stirring means based on a detection result of the detection means. It is characterized by that.

  The defoaming apparatus according to claim 6 is the defoaming apparatus according to claim 4 or 5, wherein the detection means includes a dissolved oxygen concentration meter, a density specific gravity meter, and a near-infrared transmitted / scattered light bubble detector. Any or all of these are provided.

  In the defoaming method according to claim 1 having the above-described configuration, the pressure and the defoaming state of the treatment liquid are detected, and the detected defoaming state is shifted to a preset predetermined defoaming state. Since the agitation means is automatically controlled, a good coated surface can be obtained reliably in a short time without being influenced by the type of treatment liquid or the state of mixing of bubbles. Therefore, compared with the conventional defoaming operation by setting the defoaming time taking into account the safety, defoaming compensation can be ensured, and quality assurance can be realized in the defoaming process in the production line with good reproducibility. It becomes. And by the efficient defoaming operation and the construction of a management system, the loss of bubble defects in the coating process is drastically reduced, and the production yield can be improved.

  Further, in the defoaming method according to claim 2, since the pressure and / or the agitation unit is feedback controlled based on the detected defoaming state of the processing liquid, appropriate control according to the current defoaming state of the processing liquid is performed. Can be performed. Therefore, the defoaming process can be performed more reliably and in a short time.

  Further, in the defoaming method according to claim 3, since the defoaming state is determined based on any or all values of the dissolved oxygen concentration, density specific gravity and transmitted scattered light output of the treatment liquid, From the measured values of dissolved oxygen concentration, specific gravity, and transmitted scattered light output, it is possible to refer to optimum measurement data based on the type of processing liquid to be defoamed and the current situation. Therefore, it is possible to detect an accurate defoaming state without being influenced by the type and situation of the processing liquid.

  Further, in the defoaming apparatus according to claim 4, while detecting the defoaming state of the treatment liquid, the pressure and / or so that the detected defoaming state shifts to a predetermined set defoaming state set in advance. Since the agitation means is automatically controlled, a good coated surface can be reliably obtained in a short time without being influenced by the type of processing liquid or the state of mixing of bubbles. Therefore, compared with the conventional defoaming operation by setting the defoaming time taking into account the safety, defoaming compensation can be ensured, and quality assurance can be realized in the defoaming process in the production line with good reproducibility. It becomes. And by the efficient defoaming operation and the construction of a management system, the loss of bubble defects in the coating process is drastically reduced, and the production yield can be improved.

  Further, in the defoaming apparatus according to claim 5, since the pressure and / or the stirring means is feedback controlled based on the detected defoaming state of the processing liquid, appropriate control according to the current defoaming state of the processing liquid is performed. Can be performed. Therefore, the defoaming process can be performed more reliably and in a short time.

  Furthermore, in the defoaming apparatus according to claim 6, since the defoaming state is detected by the dissolved oxygen concentration meter, the density / specific gravity meter, and the near-infrared transmission / scattering light type bubble detector, the dissolved oxygen concentration, the specific gravity, and the transmission / scattering of the treatment liquid. It is possible to refer to the optimum measurement data from each measured value of the optical output based on the type of processing liquid to be defoamed and the current situation. Therefore, it is possible to detect an accurate defoaming state without being influenced by the type and situation of the processing liquid.

  Hereinafter, a defoaming method according to the present invention and a defoaming apparatus for defoaming by the defoaming method will be described in detail with reference to the drawings. First, a schematic configuration of the defoaming apparatus 1 according to the present embodiment will be described with reference to FIG. FIG. 1 is a schematic view of a defoaming apparatus according to this embodiment.

  As shown in FIG. 1, the defoaming apparatus 1 according to this embodiment includes a sealed container 3 in which a treatment liquid 2 for performing a defoaming process is sealed, and defoaming promotion for stirring the liquid near the inner wall surface of the sealed container 3. The outer blade 4 for mixing, the inner blade 5 for mixing and stirring the processing liquid 2 located in the central portion of the sealed container 3, and the driving motor 6 that rotationally drives the outer blade 4 for promoting defoaming and the inner blade 5 for mixing and stirring. A leak valve 8 provided at the end of the exhaust pipe 7 connected to the sealed container 3 to release the atmospheric pressure inside the sealed container 3 to atmospheric pressure, a vacuum pump 9 for exhausting air, the vacuum pump 9 and the sealed container 3, a suction valve 11 for opening and closing the suction pipe 10, a supply pipe 12 for supplying the processing liquid 2 to be defoamed to the sealed container 3, and opening and closing the supply pipe 12. Supply valve 13 and defoaming treatment in sealed container 3 A drain pipe 14 for discharging the treatment liquid, and is essentially composed of a drain valve 15 for opening and closing the drain pipe 14.

  The sealed container 3 includes a mortar-shaped liquid tank 20 and a container lid 21 attached to the upper surface of the liquid tank 20. When the processing liquid 2 is being defoamed by the defoaming apparatus 1, the liquid tank 20 is Sealed by the container lid 21. A pressure gauge 22 for measuring the pressure in the sealed container 3 is provided on the upper surface of the container lid 21, while a part of the processing liquid 2 in the sealed container 3 is guided to the side surface of the liquid tank 20. The measurement pipe 23 is provided. Further, a dissolved oxygen concentration meter 25, a density specific gravity meter 26, and a near-infrared transmitted / scattered light bubble detector 27 for detecting the defoamed state of the guided processing liquid 2 are provided in the middle of the measurement pipe 23, respectively. ing. Here, since the three measurement devices 25 to 27 measure the treatment liquid 2 introduced by the measurement pipe 23, it is difficult to be affected by bubbles generated by the decompression operation, and an accurate value can be measured. It has become.

The dissolved oxygen concentration meter 25 is a measuring device that measures the current dissolved oxygen concentration (mg / L) of the treatment liquid 2. The density specific gravity meter 26 is a measuring device that measures the current specific gravity of the processing liquid 2. The near-infrared transmitted / scattered light bubble detector 27 is a measuring instrument that measures the current transmitted / scattered light output (± V) of the treatment liquid 2. Here, in order to confirm the defoaming state of the treatment liquid 2 more accurately, as in the defoaming apparatus 1 according to the present embodiment, all the measuring apparatuses (the dissolved oxygen concentration meter 25, the density specific gravity meter 26, Although it is optimal to provide the infrared transmission / scattering light type bubble detector 27), only one or two of the three measuring devices 25 to 27 may be provided. In that case, it is desirable to include a dissolved oxygen concentration meter 25 that is less affected by disturbances such as volatility and adhesiveness of the treatment liquid 2 to be measured.
In the measurement, the density hydrometer 26 needs to consider the change in the base specific gravity with respect to volatility, and the near-infrared transmitted / scattered light bubble detector 27 needs a particle calibration value for the particle dispersion system. Become. As described above, the apparatus suitable for the measurement of the defoaming state varies depending on the type and the situation of the treatment liquid 2, and the measurement is performed by all the measuring apparatuses as in the present embodiment and used for the determination of the defoaming state. It is better to select the measurement value to be used from there.

The pressure gauge 22, the dissolved oxygen concentration meter 25, the density specific gravity meter 26, and the near-infrared transmitted / scattered light type bubble detector 27 are connected to a control circuit 51 to be described later, and the measurement results of the measuring devices 22, 25-27. Is transmitted to the control circuit 51. The measurement result is displayed on a monitor 53 provided on the operation panel 52 as will be described later. Further, the control circuit 51 controls the operations of the drive motor 6, the vacuum pump 9, the leak valve 8, and the suction valve 11 as described later according to the received measurement result and the stored program.
Note that the dissolved oxygen concentration meter 25, the density specific gravity meter 26, and the near-infrared transmission / scattering light type bubble detector 27 according to the present embodiment are commercially available general measuring devices, and their structures are already known, so here Then, the detailed description is abbreviate | omitted.

The defoaming promotion outer blade 4 and the blending stirring inner blade 5 are stirring blades for stirring the treatment liquid 2 in the sealed container 3. The outer blade 4 for promoting defoaming stirs the processing liquid 2 in the vicinity of the inner peripheral surface of the sealed container 3, and the inner blade 5 for blending stirring stirs the processing liquid 2 at the center of the sealed container 3. The two blades rotate on the same rotation axis and in opposite directions as shown in FIG. The defoaming promotion outer blade 4 and the blending stirring inner blade 5 are each driven to rotate by the rotational driving force of the drive motor 6 attached to the upper part of the container lid 21.
The drive motor 6 is connected to a control circuit 51 via a drive circuit 50 described later. The control circuit 51 drives the drive motor 6 as described later according to the measured values of the measuring devices 22, 25 to 27 and stored programs. To control the operation.

Further, a branch pipe to which the exhaust pipe 7 and the suction pipe 10 are connected is connected to the container lid 21. Here, a leak valve 8 is interposed in the exhaust pipe 7 and its tip is open to the atmosphere. On the other hand, the tip of the suction pipe 10 is connected to a vacuum pump 9, and a suction valve 11 is interposed between them. The pressure in the sealed container 3 can be returned to atmospheric pressure by opening the leak valve 8, and the pressure in the sealed container 3 can be reduced by opening the suction valve 11. Therefore, the pressure in the sealed container 3 can be adjusted by opening and closing the leak valve 8 and the suction valve 11.
The vacuum pump 9, the leak valve 8 and the suction valve 11 are connected to a control circuit 51 via a drive circuit 50 which will be described later. The control circuit 51 is connected to the vacuum pump 9 and leak as described later according to a stored program. The operation of the valve 8 and the suction valve 11 is controlled.

The control circuit 51 includes a CPU that performs a control operation according to a preset program, and a ROM or RAM that is a storage unit.
The ROM stores various programs for controlling each device and unit and other various data necessary for control. The CPU performs various calculations based on various programs and data stored in the ROM.
The RAM is a memory that temporarily stores various data calculated by the CPU.

  The control circuit 51 is connected to a drive circuit 50 that controls the rotation of the drive motor 6 and also controls the drive of the vacuum pump 9 and the opening / closing operation of the leak valve 8 and the suction valve 11. Based on the control signal from the control circuit 51, the drive motor 6 and the like are controlled.

  Furthermore, a pressure gauge 22, a dissolved oxygen concentration meter 25, a density specific gravity meter 26, and a near-infrared transmitted / scattered light type bubble detector 27 are connected to the control circuit 51, and the measurement results of the measuring devices 22, 25 to 27 are obtained. The information is transmitted to the control circuit 51, and the control circuit 51 controls each peripheral device based on the transmitted information.

In addition, an operation panel 52 is connected to the control circuit 51, and the operation panel 52 is operated by the user according to each condition of the defoaming process (the sealed container 3 at the time of the defoaming process) based on the type of the processing liquid to be used. And the threshold values of dissolved oxygen concentration, specific gravity, and transmitted scattered light output described later) are set.
In addition, a monitor 53 installed on one surface of the operation panel 52 is connected to the control circuit 51. The monitor 53 includes a pressure gauge 22, a dissolved oxygen concentration meter 25, a density specific gravity meter 26, and a near infrared transmission scattered light. It is a display device that displays the measurement result of each measurement device of the method bubble detector 27 to the user.

  In this embodiment, the user sets each condition of the defoaming process (the pressure in the sealed container 3 at the time of the defoaming process, and the threshold values of the dissolved oxygen concentration, specific gravity, and transmitted scattered light output described later). Although specific values are set, optimum conditions are set in advance based on the type of the processing liquid 2 to be used, and the operation panel 52 automatically selects only the type of the processing liquid 2. It is also possible to control to perform the defoaming process under the optimum conditions. Specific control processing will be described later in detail using the flowchart of FIG.

  Next, the defoaming operation by the defoaming apparatus 1 having the above configuration will be described. Here, the defoaming apparatus 1 according to the present embodiment performs a defoaming operation on the treatment liquid 2 by selecting an operation mode on the operation panel 52. The operation mode includes “(1) Manual: All based on any setting by the user”, “(2) Semi-automatic: Perform by specifying the degree of decompression and stirring speed until the set defoaming state”, “ (3) Fully automatic: There are three types of “adjusting the degree of decompression and stirring speed based on the measured values of each measuring device until the set defoaming state is achieved”, and the program of the control circuit 51 is changed. Thus, additions and modifications can be easily made.

  Here, when “(3) Fully automatic: Perform feedback control of the degree of vacuum and the number of rotations of stirring based on the measured values of each measuring device until the set defoaming state” is selected as the operation mode below. An example of the defoaming operation will be described. FIG. 2 shows an operation flow of the defoaming apparatus 1 according to this embodiment.

  First, in step (hereinafter abbreviated as S) 1, the dissolved oxygen concentration, specific gravity, and transmission measured by the dissolved oxygen concentration meter 25, density specific gravity meter 26, and near-infrared transmitted / scattered light bubble detector 27 on the operation panel 52. Set each threshold value of scattered light output. Here, the threshold value is a condition value for ending the agitation process when the measured values of the measuring devices 25 to 27 are greater than or less than the threshold value. Here, the threshold value to be set may be any one of the dissolved oxygen concentration, specific gravity, and transmitted scattered light output, or may be set for all three. When all three are set, stirring is stopped when the measured dissolved oxygen concentration, specific gravity, and transmitted scattered light output all satisfy the threshold conditions. On the other hand, if only one or two threshold values are set, the optimum measured value (either dissolved oxygen concentration, specific gravity, or transmitted scattered light output) based on the type of processing liquid 2 to be defoamed and the current situation It becomes possible to set the end condition of the stirring with reference to only. Therefore, it is possible to detect an accurate defoaming state without being influenced by the type and situation of the processing liquid.

Subsequently, the liquid tank 20 is sealed with the container lid 21, and then the treatment liquid 2 to be defoamed is introduced into the sealed container 3 by opening the supply valve 13 (S2). Next, when an operation start button (not shown) on the operation panel 52 is operated, the leak valve 8 is closed and the suction valve 11 is opened via the drive circuit 50. Thereafter, the vacuum pump 9 is operated (S3), and suction is performed from the suction pipe 10, and the inside of the sealed container 3 is depressurized until a predetermined pressure (for example, 50 kPa) or less is set (S4: NO).
The pressure in the sealed container 3 is measured at any time by the pressure gauge 22, and the control circuit 51 automatically controls by opening and closing the suction valve 11 so as to keep the set pressure constant.

  When the pressure in the sealed container 3 becomes a set pressure (for example, 50 kPa) or less (S4: YES), the drive motor 6 is driven, and the defoaming promotion outer blade 4 and the blending stirring inner blade 5 are set to a predetermined first. The processing liquid 2 is stirred at a rotation speed (for example, 120 rpm) (S5). Here, when the treatment liquid 2 is agitated in a reduced pressure state, bubbles contained in the liquid expand and float toward the liquid surface.

Then, it is determined whether or not a predetermined time (1 second in this embodiment) has elapsed since the start of stirring (S6). After the predetermined time has elapsed (S6: YES), the dissolved oxygen concentration meter 25, the density specific gravity meter 26, and Each value of the dissolved oxygen concentration, specific gravity, and transmitted scattered light output of the current treatment liquid 2 is measured by the near-infrared transmitted / scattered light bubble detector 27 (S7). As a result, in S8, it is determined whether or not each measured value satisfies the threshold condition set in S1.
The measured values of dissolved oxygen concentration, specific gravity, and transmitted scattered light output are displayed on the monitor 53 in real time, and the data is stored in the storage area of the control circuit 51. In this embodiment, the measurement is performed at intervals of 1 second, but the measurement interval is not limited to 1 second, and may be performed at intervals of 0.5 seconds or 10 seconds.

When the set threshold value condition is cleared (S8: YES), the drive of the drive motor 6 is stopped and the treatment liquid 2 is stirred by the defoaming promoting outer blade 4 and the blending stirring inner blade 5. Stop (S9). Thereafter, the operation of the vacuum pump 9 is stopped (S10), the suction valve 11 is closed and the leak valve is opened, and the inside of the sealed container 3 is returned to atmospheric pressure (S11).
Then, after confirming that the pressure has returned to atmospheric pressure with the pressure gauge 22, the drain valve 15 is opened, and the processing liquid 2 in the sealed container 3 is discharged through the drain pipe 14.

  On the other hand, if the set threshold value condition is not cleared (S8: NO), stirring is continued and the value of the counter n stored in the storage area of the control circuit 51 is read out to “+1”. Then, it is stored again in the storage area (S13). Here, the value of the counter n is initialized to “0” when the defoaming apparatus 1 starts the defoaming process.

  Next, in S14, it is determined whether or not the count value of the counter n is “180” or more. When the count value is less than “180” (S14: NO), the process returns to S6, and whether or not a predetermined time has elapsed since the previous measurement of dissolved oxygen concentration, specific gravity, and transmitted scattered light output (S7). To be judged.

  On the other hand, if the count value is “180” or more (S14: YES), it is further determined in S15 whether the count value of the counter n is “360” or more. Here, when the counter value is less than “360” (S15: NO), the control circuit 51 controls the rotational drive of the drive motor 6, and the defoaming promotion outer blade 4 and the mixing and stirring inner blade 5 are controlled. The rotation speed is rotated at a second rotation speed (for example, 180 rpm) that is 1.5 times the first rotation speed, and the processing liquid 2 is stirred (S16). In other words, these series of processes control the measurement results of the dissolved oxygen concentration meter 25, the density specific gravity meter 26, and the near-infrared transmitted / scattered light bubble detector 27 to the stirring speed, and may be stirred for a predetermined time or longer. By increasing the rotation speed when the threshold value is not reached, a defoaming operation can be performed reliably and in a short time.

  In addition, when the count value is “360” or more (S17: YES), the control circuit 51 controls the rotation drive of the drive motor 6, and the rotation of the outer bubble 4 for promoting defoaming and the inner blade 5 for mixing and stirring is rotated. The speed is rotated at a third rotation speed (for example, 240 rpm) that is twice the first rotation speed, and the treatment liquid 2 is stirred (S17). Therefore, if the threshold is not reached even after stirring for a predetermined time or more, the defoaming operation can be performed reliably and in a short time by further increasing the rotational speed.

The operation modes that can be set by the defoaming apparatus according to the present embodiment include the above-described “(3) Fully automatic: Depressurization degree and stirring rotation based on the measured values of each measuring apparatus until the set defoaming state is reached. “(1) Manual: All based on any setting by the user”, “(2) Semi-automatic: Depressurization and agitation until set defoaming state, in addition to“ feedback control of number ”mode There are two types: “Specify the speed”, but the “(1) Manual: All based on any setting by the user” mode is the same as the defoaming operation of the conventional defoaming device. Then, the explanation is omitted.
In addition, regarding the “(2) Semi-automatic: Specifying the degree of decompression and stirring speed until the set defoaming state is specified” mode, except that the feedback control (S16, S17) is not performed, “(( 3) Fully automatic: The defoaming operation is the same as in the mode “feedback control of the degree of decompression and the stirring rotation speed based on the measured value of each measuring device until the set defoaming state is reached. The description is omitted.

  Further, if the supply valve 13 and the drain valve 15 are automatic control valves connected to the control circuit 51 by an electric circuit, after the defoaming process is completed, the drain valve 15 is released and the defoaming process is completed from the sealed container 3. It is possible to discharge the processing liquid 2 and introduce a new processing liquid 2 from the supply valve 13 by automatic control.

  Next, 20 L of water-based pressure-sensitive adhesive (acrylic emulsion: base 50%, viscosity 1 to 10 Pa · s) mixed with bubbles having a density / specific gravity of 30% as the treatment liquid 2 is put into the defoaming apparatus 1 for defoaming treatment. The measurement results obtained by the dissolved oxygen concentration meter 25, the density specific gravity meter 26, and the near-infrared transmitted / scattered light bubble detector 27 are sampled every 5 minutes, and the treatment liquid 2 in each state is sampled on the coating surface. The result of confirming the surface state of the coated surface by hand coating is shown. Further, the decompression setting / display performed on the monitor 53 is carried out while maintaining a constant absolute pressure of 10 kPa or less in order to confirm the influence of time. FIG. 3 is a graph showing measurement data of the treatment liquid performed under the above conditions.

Here, as shown in FIG. 3, (1) before the defoaming process, (2) 5 minutes after the start of the process, (3) 10 minutes after the start of the process, and (4) from the start of the process as shown in FIG. After 15 minutes, (5) the measured values of dissolved oxygen concentration, specific gravity, and transmitted scattered light output of each treatment solution 20 minutes after the start of treatment, the dissolved oxygen concentration is 0 (mg / L) as the treatment time increases. The specific gravity is 1, the transmitted scattered light output is close to 0 (± V), and it can be seen that the bubbles in the treatment liquid 2 are reduced.
And if the surface state of the coating surface which apply | coated the processing liquid 2 in (1)-(5) is confirmed, in the processing liquid of (3)-(5), application | coating nonuniformity, such as a pinhole, a streak, a crater, and a bubble baldness, will be carried out. It did not occur and a good coated surface was obtained. That is, within the shaded area in FIG. 3 (dissolved oxygen concentration in FIG. 3 0.0 to 0.5 (mg / L), specific gravity 0.98 to 1.00, transmitted scattered light output 0.0 to 0.5. By performing defoaming until the measured values of dissolved oxygen concentration, specific gravity, and transmitted scattered light output reach (± V)), it does not depend on the type of processing liquid 2 or the degree of mixing of bubbles. It is possible to perform a stable defoaming operation.
Therefore, in the water-based pressure-sensitive adhesive (acrylic emulsion system: base 50%, viscosity 1 to 10 Pa · s) used for this measurement, the threshold value (dissolved oxygen concentration 0.5, specific gravity 0. 98, transmitted scattered light output 0.5) is set in advance (FIG. 2, S1), and dissolved oxygen concentration, specific gravity and transmitted scattered light output during defoaming treatment are measured (S7), and each measured value is a threshold. By ending stirring after reaching the value (S9), reliable defoaming due to a short treatment time can be compensated for in a plurality of defoaming treatments. And it becomes possible to realize quality assurance in the defoaming process in the production line with good reproducibility.
Similarly, it is possible to obtain a necessary threshold value by performing the same measurement on other solutions of an acrylic polymer system and a UV curing system. And by setting the threshold value and performing the aforementioned defoaming automatic control process of the defoaming apparatus 1, defoaming compensation can be reliably performed, and the defoaming process step in the production line can be performed with good reproducibility. Quality assurance can be realized.

As described above in detail, in the defoaming apparatus 1 and the defoaming method according to the present embodiment, the dissolved oxygen concentration meter 25, the density specific gravity meter 26, and the near-infrared transmitted scattered light type bubble detector 27 are provided, and the sealed container 3 And measuring each measured value of dissolved oxygen concentration, specific gravity and transmitted scattered light output of the treatment liquid 2 during the defoaming process, and determine whether or not the measured value has reached the set threshold value, Since the stirring of the processing liquid 2 by the outer blade 4 for promoting defoaming and the inner blade 5 for mixing and stirring is stopped when it reaches, it does not depend on the type of the processing liquid 2 or the state of mixing of bubbles, and in a short time A good coated surface can be obtained with certainty. Therefore, compared with the conventional defoaming operation by setting the defoaming time taking into account the safety, defoaming compensation can be ensured, and quality assurance can be realized in the defoaming process in the production line with good reproducibility. It becomes. And by the efficient defoaming operation and the construction of the management system, the bubble defect loss in the coating process is drastically reduced, and the production yield can be improved.
In addition, since the agitation speed of the defoaming promotion outer blade 4 and the mixing and agitation inner blade 5 is feedback controlled based on the detected defoaming state of the processing liquid, it is appropriate for the current defoaming condition of the processing liquid 2 It is possible to perform simple control. Therefore, the defoaming process can be performed more reliably and in a short time.
Furthermore, the defoaming apparatus 1 according to the present embodiment is provided with a dissolved oxygen concentration meter 25, a density specific gravity meter 26, and a near-infrared transmission / scattering light type bubble detector 27, respectively, and the dissolved oxygen concentration, specific gravity, and transmission scattering of the treatment liquid 2 are provided. It is possible to refer to the optimum measurement data from each measurement value of the optical output based on the type of the treatment liquid 2 to be defoamed and the current situation. Therefore, it is possible to detect an accurate defoaming state without being influenced by the type and situation of the processing liquid.

Note that the present invention is not limited to the above-described embodiment, and various improvements and modifications can be made without departing from the scope of the present invention.
For example, in the present embodiment, stirring is performed when the measured values of the dissolved oxygen concentration, specific gravity, and transmitted scattered light output of the treatment liquid 2 during the defoaming process do not reach predetermined threshold values (S8: NO). Although the speed is increased to promote defoaming, the opening of the suction valve 11 may be further controlled to reduce the pressure in the sealed container 3. As a result, bubbles in the processing liquid that do not reach the threshold value within a predetermined time can be further expanded to promote defoaming.

  In the present embodiment, the threshold value is set by the operation panel 52 when performing the defoaming process. However, a threshold value corresponding to the type of the processing liquid is set in the storage area of the control circuit 51 in advance. The operation panel 52 may select only the type of the processing liquid 2 to be defoamed. Thereby, the defoaming process can be performed by adjusting the stirring speed and the pressure in the sealed container 3 to optimum values according to the type of the selected processing liquid.

  By detecting the defoaming state of the processing liquid during the defoaming process, the present invention reliably obtains a good coated surface in a short time without being influenced by the type of the processing liquid or the state of mixing of bubbles. It is possible to provide a defoaming method and a defoaming apparatus that can perform the defoaming.

It is the schematic of the defoaming apparatus which concerns on this embodiment. It is explanatory drawing which shows the operation | movement flow of the defoaming apparatus which concerns on this embodiment. It is the graph which showed the measurement data of the process liquid at the time of performing a defoaming process with the defoaming apparatus which concerns on this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Defoaming device 2 Processing liquid 3 Sealing device 4 Outer blade for promoting defoaming 5 Inner blade for mixing and stirring 6 Drive motor 9 Vacuum pump 11 Suction valve 22 Pressure gauge 25 Dissolved oxygen concentration meter 26 Density specific gravity meter 27 Near infrared transmission scattered light Bubble detector 51 Control circuit 52 Operation panel

Claims (6)

In the defoaming method of separating the processing liquid into bubbles and liquid by placing the processing liquid mixed with bubbles in a state where the pressure is reduced to a predetermined pressure and stirring with stirring means,
The degassing state of the treatment liquid is detected, and the pressure and / or the stirring means is automatically controlled so that the detected defoaming state shifts to a preset predetermined defoaming state. Defoaming method.   The defoaming method according to claim 1, wherein the pressure and / or the stirring unit is controlled based on the detected defoaming state of the processing liquid.   2. The detected defoaming state is determined based on any one or all values of dissolved oxygen concentration, density specific gravity and transmitted scattered light output of the treatment liquid. Item 3. The defoaming method according to Item 2. A sealed container for enclosing the processing solution;
Decompression means for decompressing the inside of the sealed container;
In the defoaming device having a stirring means for stirring the processing liquid sealed in the sealed container,
Setting means for setting a predetermined defoaming state;
Detecting means for detecting a defoamed state of the treatment liquid;
Automatic control means for automatically controlling the pressure reducing means and / or the stirring means so that the defoamed state detected by the detecting means shifts to the set defoamed state set by the setting means. Defoaming device characterized.   The defoaming apparatus according to claim 4, wherein the automatic control unit controls the decompression unit and / or the stirring unit based on a detection result of the detection unit.   The defoaming device according to claim 4 or 5, wherein the detection means includes any one or all of a dissolved oxygen concentration meter, a density specific gravity meter, and a near-infrared transmitted / scattered light bubble detector. .

Images