JPH11276959A - Coating film thickness controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correctly control the thickness of a coating film formed on the surface of a long-length sheet to the object thickness. SOLUTION: In a coating film thickness controller, in a process for forming a gap operation signal for controlling a liquid sending gap 6 of a coater 1 for sending adhesive agent liquid S fed to the surface of a long-length sheet 2 continuously conveyed, by incorporating a variation in temperature of the adhesive agent liquid S and a variation in conveying speed of the long-length sheet 2, a ratio G(=ΔY/Δd) of variations ΔY in thickness of the adhesive agent film Q to variations Δd in space of the gap obtained in advance for controlling the thickness of the adhesive agent film Q is corrected by the same amount as deviating from the precise value, thereby enabling accurately controlling the thickness of the adhesive agent film Q continuously formed on the surface of the long-length sheet 2 to the object thickness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating film thickness control device for controlling the thickness of a coating film in a continuous coating step for continuously forming a coating film on the surface of a long sheet.

[0002]

2. Description of the Related Art For example, in the process of manufacturing an adhesive tape or an adhesive sheet, as shown in FIG.
Are formed continuously. In the coating device 50, the long sheet 51 is continuously conveyed in the directions indicated by arrows RA and RB while being wound so as to press the entire back surface against the front surface of the backup roll 52. On the other hand, a coating roll 53 and a metering roll 54 are provided on the opposite side of the backup roll 52 so as to face each other with a liquid sending gap 55 therebetween.
A liquid reservoir 56 for storing a viscoelastic pressure-sensitive adhesive liquid S is provided on the rear side.

In the case of a conventional continuous coating process, FIG.
As shown in FIG.
The adhesive liquid S is first sent out onto the surface of the coating roll 53. With the rotation of the coating roll 53, the adhesive liquid S is transferred to the surface of the long sheet 51 supported by the backup roll 52, and the adhesive film Q is continuously formed on the surface of the long sheet 51. .

[0004]

However, in the above conventional case, there is a problem that it is difficult to accurately set the thickness of the pressure-sensitive adhesive film Q to a target thickness. Of course, the adhesive film Q
The control for setting the thickness of the target to the target thickness is performed. The thickness of the adhesive film Q is determined by the gap 55 for liquid delivery of the coating device 50.
Of the pressure-sensitive adhesive film Q set in advance.
Of the gap 55 is set according to the target thickness. However, the variation factor of the thickness of the adhesive film Q is the gap 5
It's not just five intervals.

Accordingly, a gap interval variable mechanism 57 for changing the interval of the gap 55, a coating film thickness detector 58 for detecting the thickness of the adhesive film Q formed on the surface of the long sheet 51, and a coating film thickness detecting device A gap control unit 59 that sends a gap operation signal for adjusting the gap 55 to the gap gap variable mechanism 57 in accordance with the difference (thickness deviation) between the detected thickness of the pressure-sensitive adhesive film Q by the device 58 and a preset target thickness. Is provided, and the thickness of the adhesive film Q is controlled to be the target thickness by changing the interval of the liquid sending gap 55 by the gap operation signal. However, the current state of the art is that the conventional coating film thickness control device does not accurately reach the target thickness of the adhesive film Q.

SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide a coating film thickness control device capable of accurately setting a target coating film thickness to be continuously formed on the surface of a long sheet. And

[0007]

In order to solve the above-mentioned problems, a coating film thickness control apparatus according to the present invention provides a coating apparatus for applying a viscoelastic liquid to the surface of a continuously conveyed long sheet. An apparatus for controlling the thickness of the coating film in a continuous coating step of continuously feeding from the liquid delivery gap and continuously forming a coating film on the surface of the long sheet, wherein the gap between the liquid delivery gap is A variable gap interval changing means, a coating film thickness detecting means for detecting the thickness of the coating film formed on the surface of the long sheet, and a detection thickness of the coating film by the coating film thickness detecting means and a preset target thickness. A gap control unit for sending a gap operation signal for adjusting the gap interval based on the difference (film thickness deviation) to a gap interval variable unit, and a liquid temperature detection unit for detecting a temperature of the viscoelastic liquid. Equipment And, the gap control means, characterized in that a temperature correction means for performing a temperature correction corresponding to the temperature detected by the liquid temperature detecting means during the creation of the gap operation signal.

According to a second aspect of the present invention, in the control apparatus for controlling the thickness of the coating film according to the first aspect, a transport speed detecting means for detecting a transport speed of the long sheet is provided, and the gap control means includes: A speed correcting means for performing a speed correction according to the speed detected by the transport speed detecting means when generating the gap operation signal is provided.

[0009]

Next, the operation of controlling the thickness of the coating film according to the first aspect of the present invention will be described. When controlling the thickness of the coating film according to the present invention, a liquid having viscoelasticity is continuously fed from the liquid delivery gap of the coating apparatus to the surface of the long sheet that is continuously conveyed, and the length of the long sheet is controlled. At the same time as the coating film is continuously formed on the surface, the thickness of the coating film formed on the surface of the long sheet is detected by the coating film thickness detecting means, and the viscoelasticity is detected by the liquid temperature detecting means. Is detected. The gap control means sends a gap operation signal for adjusting the interval of the liquid sending gap based on the difference (thickness deviation) between the detected thickness of the coating film and a preset target thickness. Is generated while folding in the temperature correction according to the above and sent to the gap interval varying means. The gap interval variable unit that has received the gap operation signal from the gap control unit adjusts the interval of the liquid delivery gap in accordance with the signal intensity of the gap operation signal. If the detected thickness exceeds the target thickness,
If the gap interval is narrowed, and if the detected thickness is less than the target thickness, the gap interval is increased.

That is, the fluidity of a liquid having viscoelasticity is considerably different if the liquid temperature is different. Therefore, if the liquid temperature of the liquid having viscoelasticity changes, the gap from the gap is the same even if the gap interval is the same. Fluid delivery varies. If the liquid temperature is high, the fluidity becomes better and the amount of delivery decreases and the coating becomes thinner.If the liquid temperature is low, the fluidity becomes worse and the amount of delivery increases and the coating becomes thicker. It deviates from the target thickness. On the other hand, in the case of the present invention, the gap operation signal is corrected by the temperature measurement result of the viscoelastic liquid,
As a result of the temperature of the liquid having the viscoelasticity being reflected in the adjustment of the gap interval, even if the liquid temperature changes, the thickness deviation of the coating film due to the liquid temperature change does not occur. Incidentally, the gap interval is increased in accordance with the increase in the liquid temperature, and conversely, the gap interval is reduced in accordance with the decrease in the liquid temperature.

In the case of controlling the thickness of the coating film according to the second aspect of the present invention, the conveying speed detecting means detects the conveying speed of the long sheet, and the gap controlling means comprises:
The gap operation signal is created while incorporating a speed correction corresponding to the speed detected by the transport speed detecting means. If the transport speed of the long sheet is fast, the coating amount tends to decrease and the coating becomes thin, and if the transport speed of the long sheet is slow, the coating amount tends to increase and the coating becomes thicker. It will shift from. On the other hand, in the case of claim 2, the gap operation signal is corrected based on the measurement result of the long sheet conveyance speed, and the conveyance speed of the long sheet is reflected in the adjustment of the gap interval. Even if there is a change in the transport speed, the thickness shift of the coating film due to the change in the speed does not occur.
Incidentally, the gap interval is increased according to the increase in the transport speed, and conversely, the gap interval is reduced according to the decrease in the transport speed.

[0012]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the overall configuration of a continuous coating system using a coating film thickness control device according to an embodiment.

The continuous coating system (hereinafter, abbreviated as “system” as appropriate) of the embodiment is, as shown in FIG.
This is a system in which a pressure-sensitive adhesive film Q is continuously formed on the surface of a long sheet 2 which is a thin support substrate of a pressure-sensitive adhesive tape or a pressure-sensitive adhesive sheet using a top feed reverse type coating apparatus 1.
In the coating apparatus 1, the long sheet 2 is continuously conveyed in the directions indicated by arrows RA and RB while being wound so as to press the entire back surface against the front surface of the backup roll 3.
Specific examples of the long sheet 2 for a support substrate include a plastic film, paper, and metal foil.

On the other hand, the backup roll 3 of the coating apparatus 1
On the opposite side, a metal coating roll 4 and a metalling roll 5 are installed so as to face each other up and down with a liquid sending gap 6 therebetween.
A liquid reservoir 7 for storing the pressure-sensitive adhesive liquid S is provided on the rear side of 5.

The adhesive liquid S in the liquid reservoir 7 is a viscoelastic adhesive. Specific examples of the adhesive include a rubber-based adhesive, an acrylic-based adhesive, and a silicone-based adhesive.

Further, the coating apparatus 1 is provided with a variable gap interval mechanism 8 for adjusting the interval between the liquid delivery gaps 6 by changing the distance between the axes of the coating roll 4 and the metering roll 5. In the case of the coating apparatus 1 of the embodiment, the distance between the axes of the coating roll 4 and the metalling roll 5 is changed by moving the metalling roll 5 upward or downward.

Further, in the system of the embodiment, a film thickness detector 9 for measuring the thickness of the pressure-sensitive adhesive film Q formed on the surface of the long sheet 2 is provided on the lower side of the backup roll 3. As a specific film thickness detector 9, when the long sheet 2 shows a spectrum distribution different from that of the pressure-sensitive adhesive film in the near-infrared region and no excessive attenuation at the used near-infrared wavelength is observed, A film thickness detector of the formula is suitable.
This is because the near-infrared type film thickness detector can measure only the thickness of the pressure-sensitive adhesive film Q based on the change in the intensity of reflected or transmitted light of the irradiated measurement light.

If the measurement is inappropriate with a near infrared type film thickness detector for the long sheet 2, a beta ray type, γ ray type or laser type film thickness detector is suitable. In the case of these detectors, since the measurement results include the thickness of the long sheet 2, the thickness of only the long sheet 2 before forming the adhesive film Q is separately measured, and the thickness of the thickness detector 9 is measured. A process is required to obtain the thickness of the pressure-sensitive adhesive film Q by subtracting the thickness of the long sheet 2 from the measurement result. Hereinafter, in the system of the embodiment, the description will be made on the assumption that the film thickness detector 9 is a near-infrared type film thickness detector and only the thickness of the adhesive film Q is directly obtained by the film thickness detector 9.

The thickness of the pressure-sensitive adhesive film Q detected by the film thickness detector 9 is determined by the main operation unit 13 of the gap control unit 13.
sent to a. On the other hand, the system of the embodiment is provided with a target thickness setting unit 14 for presetting the target thickness of the pressure-sensitive adhesive film Q, and the target thickness of the pressure-sensitive adhesive film Q set in the target thickness setting unit 14 is also: Main operation unit 1 of gap control unit 13
3a.

Further, in the system of the embodiment, a liquid temperature detector 10 for detecting the temperature of the adhesive liquid S in the liquid reservoir 7 is provided, and a roll temperature detection for detecting the temperature of the backup roll 3 is provided. A roll temperature detector 12 for detecting the temperature of the coating device 4 and the coating roll 4 is provided. The pressure-sensitive adhesive liquid temperature obtained by the liquid temperature detector 10, the backup roll temperature obtained by the roll temperature detector 11, and the coating roll temperature obtained by the roll temperature detector 12 are sent to the temperature correction unit 13b of the gap control unit 13. It is configured to be sent.

In addition, in the case of the system of the embodiment, a transport speed detector 15 for detecting the transport speed of the long sheet 2 which is continuously transported is provided. The detection result of the transport speed obtained by the transport speed detector 15 is the
3 is sent to the speed correction unit 13c.

The gap control unit 13 determines the difference between the detected thickness Y _pv of the adhesive film Q and the target thickness Y _SV of the adhesive film Q (film thickness deviation = Y _SV −Y _pv ) and a predetermined reference value. A gap operation signal for adjusting the interval of the liquid delivery gap 6 based on a ratio G (= ΔY / Δd) of the thickness variation ΔY of the coating film to the gap variation Δd of the gap determined in advance under the condition. The gap correction signal is generated and sent to the gap interval variable mechanism 8, and the temperature correction and the speed correction are inserted in the process of generating the gap operation signal. That is, the gap control unit 13 includes a main calculation unit 13a that performs a PID calculation or the like on a film thickness deviation, and a temperature correction unit 13b that performs a temperature correction process.
And a speed correction unit 13c for performing a speed correction process.
Finally, a gap operation signal D represented by the following equation is output to the gap interval variable mechanism 8. D = [(1 / G) × f ₀ (Y _SV −Y _pv )] × [K _T × f
_T (T ₁ , T ₂ , T ₃ , T _B )] × [K _V × f
_{V (V 1, V B)]}

The main calculation unit 13a performs a PID calculation process on the film thickness deviation, and sends a calculation result of (1 / G) · f ₀ (Y _SV −Y _pv ) to the next temperature correction unit 13b. Where G
Is the ratio (G = ΔY / Δd) of the gap change amount Δd and the thickness change amount ΔY of the adhesive film Q at the reference temperature T _B and the reference transport speed V _{B under} predetermined reference conditions. The constant to be set. f ₀ is a PID or a similar operation function. Y _SV is the target thickness of the adhesive film Q. Y _pv is the detected thickness of the adhesive film Q.
Of course, in the system of the embodiment, the film thickness deviation (Y _SV −Y _pv )
If> 0, it means that the film thickness of the pressure-sensitive adhesive film S has not reached the target thickness, so that the gap 6 is finally widened,
If (Y _SV −Y _pv ) <0, it means that the thickness of the pressure-sensitive adhesive film S exceeds the target thickness.
Needless to say, the control configuration is narrowed.

The temperature compensator 13b has a film thickness corresponding to a temperature change.
The temperature correction process is performed to prevent fluctuations.
In general, the output of the main operation unit 13a is K_T・ F_T(T₁,
T_Two, T _Three, T_BMultiply by the temperature correction ratio
Perform (multiply) operations. Where K_TIs the temperature fluctuation
The pressure-sensitive adhesive property coefficient for correction, the base ratio of the pressure-sensitive adhesive liquid S
Set in advance according to (adhesive solids / total)
Is the coefficient to be calculated. f _TIs the temperature correction function, T₁Is an adhesive
Liquid temperature, T_TwoIs the backup roll temperature, T_ThreeIs a coat
Roll temperature, T_BIs the reference temperature when G was determined
You.

When the temperatures T _{1 to} T ₃ fluctuate, the pressure-sensitive adhesive liquid S
Varies in thickness. The temperature correction ratio indicating the change ratio of the interval of the liquid sending gap 6 for canceling the change in the film thickness of the pressure-sensitive adhesive liquid S due to the change in the temperature T _{1 to} T ₃ is experimentally obtained in advance, and the main calculation is performed. The output of the unit 13a is multiplied. As a result, the temperature correction unit 13b calculates [(1 / G)
× f ₀ (Y _SV −Y _pv )] × [K _T × f _T (T ₁ , T ₂ ,
T ₃ , T _B )].
Generally the thickness of about adhesive solution S is adhesive solution temperatures T ₁ increases in a practical use range becomes thinner. Further, the backup roll temperature T ₂ and the coating roll temperature T ₃
The temperature of the pressure-sensitive adhesive liquid S changes even if the temperature changes. However, since the influence of the pressure-sensitive adhesive liquid temperature T ₁ acts most remarkably, if the temperatures T _{1 to} T ₃ change similarly, the temperature correction ratio f _T (T ₁ , T ₂ , T ₃ , As shown in FIG. 2, T _B ) is higher when the temperature is higher than when the temperature is lower.

The temperature corrector 13b calculates the temperatures T ₁ , T ₂ ,
The values of the temperature correction ratios for various combinations of the numerical values of T ₃ and T _B are stored in the form of a table, and the temperature correction ratios corresponding to the detected temperatures from the respective temperature detectors 10 to 12 are read to perform the temperature correction. It is configured to execute processing. Since the temperature correction ratio differs depending on the type of the adhesive, the temperature correction ratio is obtained in advance for each adhesive, and a temperature correction ratio suitable for each adhesive to be used is used.

The speed correcting section 13c is for conveying the long sheet 2
Speed correction processing to prevent film thickness fluctuations due to speed changes
And specifically, the output of the temperature correction unit 13b.
And K _V× f_V(V₁, V_B) Multiplied by the speed correction ratio
Performs a combining (multiplying) operation. Where K_VHa
The pressure-sensitive adhesive property coefficient for correcting the feeding speed fluctuation,
Is determined in advance according to the base ratio (solid content of adhesive / total)
This is the coefficient that is set. f_VIs the transport speed correction function
Number, V₁Is the transport speed of the long sheet, V_BSought G
It is the reference speed at the time.

The transport speed V ₁ of the long sheet 2 is equal to the reference speed V.
_When it deviates from _B, the film thickness of the pressure-sensitive adhesive liquid S changes. The speed correction ratio of the spacing of the liquid delivery for gaps 6 for canceling the variations in thickness of the pressure-sensitive adhesive solution S accompanying the change in the conveyance speed V ₁ of the此determined in advance experimentally, subjected to output of the temperature compensation unit 13b Match them. Therefore, the speed correction unit 13c outputs the above-described gap operation signal D.

If the transport speed V ₁ of the long sheet 2 increases, the film thickness of the pressure-sensitive adhesive liquid S decreases, so that the speed correction ratio f _V (V ₁ , V _B ) is as shown in FIG. As a result, the transport speed increases as the transport speed increases.
Than when people of the time ₁ is fast is slow transport speed V _1, so that the gap is expanded.

The speed correction unit 13c stores the values of the speed correction ratios for various values of the speeds V ₁ and V _B in the form of a table, and stores the speed correction ratios according to the temperature detected by the transport speed detector 15. It is configured to read out and execute the speed correction processing. Since the speed correction ratio also varies depending on the type of the adhesive, the speed correction ratio is determined in advance for each adhesive, and a speed correction ratio suitable for each adhesive to be used is used.

The process of generating the gap operation signal in the gap control section 13 is shown in the flowchart of FIG. Further, the main calculation unit 13a and the temperature correction unit 13
The b and the speed correction unit 13c are mainly configured by a central processing unit (CPU), a memory device, and operating software.

On the other hand, the gap interval variable mechanism 8 to which the gap control signal D is sent from the gap control unit 13 is
According to the signal strength of the received gap operation signal D,
The gap 6 is adjusted so that the distance between the axes of the coating roll 4 and the metalling roll 5 is changed by moving the metalling roll 5 upward or downward, and the thickness of the pressure-sensitive adhesive film S becomes the target thickness.

Next, the operation of controlling the thickness of the pressure-sensitive adhesive film when the continuous coating system of the embodiment having the above-described configuration is operated will be described. Control operation of pressure-sensitive adhesive film thickness with respect to temperature change of pressure-sensitive adhesive liquid S For example, in the morning when the system started operating, the ambient temperature was low,
The pressure-sensitive adhesive liquid S has poor fluidity at low temperatures, but as the ambient temperature rises as the operation continues, the temperature of the pressure-sensitive adhesive liquid S increases and the fluidity improves. Therefore, the adhesive liquid S
In the morning when the temperature is low, the temperature correction ratio is low, the gap operation signal D is small, the interval between the gaps 6 is small, and even if the fluidity of the adhesive liquid S is poor, an appropriate amount of the adhesive liquid can be obtained. Can be Then, as the temperature of the pressure-sensitive adhesive liquid S rises and the fluidity improves, the temperature correction ratio becomes higher. As a result, the gap operation signal D becomes larger and the interval between the gaps 6 becomes wider. In addition, an appropriate amount of the adhesive liquid can always be obtained in accordance with the improvement in the fluidity of the adhesive liquid S. Of course, the liquid temperature fluctuations caused by factors other than the elapse of the operation time also cause a change in the temperature correction ratio, the gap operation signal D is changed, and the interval of the gap 6 is automatically adjusted. Needless to say, the amount of the adhesive liquid is always maintained.

The operation of controlling the thickness of the pressure-sensitive adhesive film with respect to the temperature change of the backup roll and the coating roll The same temperature change as the temperature change of the pressure-sensitive adhesive liquid S occurs in both the rolls 3 and 4. Since the temperature change between the two rolls 3 and 4 changes the gap 6 and the contact pressure between the two rolls 3 and 4, when the temperature changes, the film thickness of the pressure-sensitive adhesive film Q changes. In general, the influence of the interval of the gap 6 acts most remarkably, so that as the temperature increases, the thickness of the pressure-sensitive adhesive film Q decreases, which is the same as the relationship between the temperature of the pressure-sensitive adhesive liquid S and the film thickness. Therefore, in this case, the control operation is the same as that in the case of the pressure-sensitive adhesive liquid S, and the subsequent description will be omitted.

The operation of controlling the thickness of the pressure-sensitive adhesive film with respect to the fluctuation of the conveying speed of the long sheet.
_The coating process is performed while the long sheet 2 is conveyed at a speed lower than ₀ , and when it becomes stable, the conveying speed is increased to the reference speed V ₀ to improve the efficiency of the coating process depending on the application mode. In this case, at startup, the speed correction ratio is low and the gap operation signal D
Is small, and the interval of the gap 6 is narrowed, so that an appropriate amount of the pressure-sensitive adhesive liquid can be obtained. When the transport speed increases to the reference speed V ₀ , the speed correction ratio increases to the reference ratio, the gap operation signal D increases, and the gap 6 is widened. Of course, if the transport speed of the long sheet 2 fluctuates other than at the time of startup, the speed correction ratio changes, the signal intensity of the gap operation signal D changes, and the gap 6 is automatically expanded. Alternatively, as a result of the narrowing, the thickness of the pressure-sensitive adhesive film Q is accurately maintained at the target thickness even if the transport speed varies.

The present invention is not limited to the above embodiment, but can be modified as follows. (1) The coating film thickness control device of the present invention is not limited to the coating device 1 shown in FIG. 1, but can be applied to a coating device without a metering roll as shown in FIG. is there. The coating apparatus of FIG. 5 has a configuration in which the interval of the gap 6 is changed by moving the coating roll 4 upward or downward. Alternatively, in FIG. 1, the present invention can be applied to a coating apparatus using a blade (blade) instead of a metering roll. In this coating apparatus, the gap is changed by moving the blade upward or downward.

(2) The film to be controlled by the coating film thickness control device of the present invention is not limited to the adhesive liquid. For example, a coating film formed of a viscoelastic liquid such as a paint film can be controlled by the present invention.

(3) In the case of the embodiment, the operation control in the main operation unit 13a is a classic PID,
The arithmetic control by a may be advanced PID, fuzzy control, prediction control, or the like.

(4) In the case of the embodiment, the gap operation signal is generated while folding the correction according to the temperature of the pressure-sensitive adhesive liquid, the temperature of each roll, and the conveyance speed of the long sheet. Any configuration is possible as long as the gap operation signal is generated while at least correcting the temperature corresponding to the pressure-sensitive adhesive liquid.

[0040]

As described above, according to the coating film thickness control apparatus of the present invention, the viscoelastic liquid fed from the liquid sending gap of the coating apparatus to the surface of the long sheet is removed. The gap operation signal is corrected by the detected temperature, and the temperature of the liquid having viscoelasticity is reflected in the adjustment of the gap interval.As a result, even if the liquid temperature changes, the thickness deviation of the coating film due to the liquid temperature change is not changed. This does not occur, and the thickness of the coating film continuously formed on the surface of the long sheet can be accurately set to the target thickness.

Further, according to the coating film thickness control device of the present invention, the gap operation signal is corrected based on the measurement result of the long sheet conveyance speed, and the long sheet conveyance speed is adjusted for the gap interval. As a result, even if the transport speed of the long sheet changes, the thickness deviation of the coating film due to the change in the speed does not occur, and the thickness of the coating film accurately reaches the target thickness.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an overall configuration of a continuous coating system used for implementing a coating film thickness control device according to an embodiment.

FIG. 2 is a graph showing an example of a correspondence relationship between a temperature correction ratio and a temperature in the control device of the embodiment.

FIG. 3 is a graph showing an example of a correspondence relationship between a speed correction ratio and a speed in the control device according to the embodiment.

FIG. 4 is a flowchart illustrating a process of generating a gap operation signal in a gap control unit according to the embodiment.

FIG. 5 is a schematic diagram showing a main configuration of another coating apparatus that can be used for implementing the coating film thickness control apparatus of the present invention.

FIG. 6 is a schematic diagram showing a main configuration of a continuous coating system used for implementing a conventional coating film thickness control device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Coating apparatus 2 ... Long sheet 3 ... Backup roll 4 ... Coating roll 5 ... Metalling roll 6 ... Liquid sending gap 8 ... Gap interval variable mechanism 9 ... Film thickness detector 10 ... Liquid temperature detector 11, 12 ... Roll temperature detector 13 ... Gap control unit 13a ... Main operation unit 13a 13b ... Temperature correction unit 13c ... Speed correction unit 14 ... Target thickness setting unit Q ... Adhesive film S ... Adhesive liquid

Claims (2)

[Claims] A viscoelastic liquid is continuously fed to the surface of a long sheet that is continuously conveyed from a liquid delivery gap of a coating apparatus, and a coating film is continuously formed on the surface of the long sheet. An apparatus for controlling the thickness of the coating film in a continuous coating step to be formed, comprising: a gap interval variable means for changing an interval of the liquid delivery gap; and detecting a thickness of the coating film formed on the surface of the long sheet. A gap operation signal for adjusting the gap interval based on a difference (film thickness deviation) between a detected thickness of the coating film by the coating thickness detector and a preset target thickness. A gap control unit for sending to the variable unit; and a liquid temperature detection unit for detecting a temperature of the liquid having the viscoelasticity. Controller of the coating thickness, characterized in that a temperature correction means for performing a temperature correction corresponding to the temperature detected by the means. 2. A control apparatus for controlling the thickness of a coating film according to claim 1, further comprising a conveying speed detecting means for detecting a conveying speed of the long sheet, and wherein said gap controlling means conveys the gap when generating a gap operation signal. An apparatus for controlling the thickness of a coating film provided with a speed correcting means for performing a speed correction according to a speed detected by the speed detecting means.