JP2012066226A - Coating solution circulating device and coating solution circulating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating solution circulating device and a coating solution circulating method which can suppress the occurrence of a coating defect.SOLUTION: The coating solution circulating device 1 in which a coating solution 2 for coating a belt-shaped base material conveyed in the longitudinal direction is supplied into a coating solution pan 4 and discharged/recovered from the coating solution pan 4 includes a plurality of coating solution outlets 8 which are formed in the bottom of the coating solution pan 4 and discharge the coating solution 2 from the coating solution pan 4, a coating solution discharge control plate 12 for opening/closing the coating solution outlets, a load sensor 22 which detects the opening/closing actions of the coating solution discharge control plate 12 and the amount of the coating solution 2, and a coating solution discharge control plate driving device 13 which automatically controls the action of the coating solution discharge control plate in accordance with an electric signal from the load sensor 22.

Description

  TECHNICAL FIELD The present invention relates to an apparatus and method for repeatedly supplying and discharging a coating liquid in a coating liquid pan provided in a coating apparatus, and particularly to a coating liquid pan provided in a gravure coating machine. The present invention relates to an apparatus and a method for circulating a certain amount of a coating liquid containing high viscosity or particles in a pan without maintaining the uniform viscosity and settling particles or the like.

  As a coating film forming method for producing a coated product by applying a coating liquid to a belt-shaped substrate such as a film substrate to form a coated film, for example, there is a gravure coating method. In the gravure coating method, the coating liquid such as ink or coating agent is supplied to the surface of the gravure roll with the cells formed on the circumferential surface, and the excess coating adhered on the circumferential surface of the gravure roll. This is a coating method in which the liquid in the cell is transferred to the substrate after the liquid is scraped off by a doctor blade.

  In such a gravure coating, as a method of supplying the coating liquid to the gravure roll, generally, a method of immersing the gravure roll in the coating liquid supplied in the coating liquid pan having a ship-shaped bottom. Is adopted.

  With reference to FIG. 3, the general coating liquid supply method and the coating liquid circulation method will be described. FIG. 3 is a schematic view showing a coating liquid circulation method in general gravure printing.

  In a general coating liquid supply method, as shown in FIG. 3, a gravure roll 24, a doctor blade 26, an impression cylinder 28 (backup roll), a coating liquid tank 30, a coating liquid supply pump 32, A coating liquid circulation device 1 including a coating liquid recovery pump 34, a coating liquid pan 4, a coating liquid recovery pipe 20, and a coating liquid supply pipe 18 is used.

  And in the coating liquid supply method performed using the coating liquid circulation apparatus 1, the coating liquid pan 4 is filled with the coating liquid 2 such as ink or coating agent, and the coating in the coating liquid pan is performed. The lower part of the gravure roll 24 is immersed in the liquid, and the gravure roll is rotated.

  Thereby, the coating liquid is supplied to the entire circumferential surface of the gravure roll, the supplied coating liquid is scraped off with a doctor blade, and the coating liquid in the cell is removed from the surface of the substrate 36. To be transferred.

  Here, when the amount of the coating liquid 2 in the coating liquid pan 4 is reduced to some extent, the coating liquid circulation device 1 replenishes the coating liquid 2 into the coating liquid pan 4 and applies the coating liquid 2 every time. A countermeasure is taken to keep the working liquid 2 in an appropriate amount.

  Specifically, the coating liquid tank 30 is filled with the coating liquid 2, and the coating liquid 2 is supplied into the coating liquid pan 4 by the coating liquid pump 32 through the coating liquid supply pipe 18. In the coating liquid pan 4, the weir 6 that sets the liquid level to a certain level is provided, so that the excess coating liquid 2 is returned from the coating liquid recovery pipe 20 to the coating liquid tank 30. It is. In this way, the coating liquid 2 is replenished in the coating liquid pan 4 and the coating liquid 2 in the coating liquid pan 4 is circulated through the coating liquid tank 30.

  Moreover, as a coating liquid pan, there exist a thing of the structure described in patent document 1 or patent document 2, for example other than the thing of the structure shown in FIG.

The coating liquid pan described in Patent Document 1 is conventionally known as a coating liquid pan for a gravure roll. Specifically, at a position near the peripheral surface of the gravure roll on the side that comes out of the coating liquid by rotation, a position that is lower than the storage level of the coating liquid, or a position that extends from higher to lower than the storage level of the coating liquid. The intermediate plate in which notches and holes are formed is provided higher than the coating liquid storage level. Thereby, the coating liquid supplied from the coating liquid replenishing section is discharged from a notch or the like of the intermediate plate.

  However, in the coating liquid pan described in Patent Document 1, since the flow of the coating liquid tends to stay at the corner portion of the coating liquid pan, the viscosity of the upper layer of the coating liquid increases at this portion, and the gravure It may be difficult to supply a coating solution having a constant viscosity to the surface of the plate, which may cause a problem that a coating defect occurs. This problem is particularly noticeable when a highly viscous coating solution is used.

  In addition, the coating liquid pan described in Patent Document 2 is provided with a coating liquid supply unit at the upper edge end of the rectangular casing included in the coating liquid pan in order to prevent partial retention of the coating liquid. And an overflow notch and a lower opening are provided above and below the other side.

  In the coating liquid pan described in Patent Document 2, it is possible to prevent a partial increase in the coating liquid viscosity and to supply a coating liquid having a constant viscosity to the gravure plate cylinder. However, when the coating liquid contains particles with high viscosity and easily settles, it is difficult for the coating liquid to flow out uniformly from the overflow notch and the lower opening provided on one side of the coating liquid pan. As a result, particles settle on the side where the lower opening is not provided, and if the circulation is continued as it is, a high-viscosity coating liquid containing particles cannot be uniformly supplied, and stable coating cannot be performed. May occur.

JP-A-2-297443 JP 7-314649 A

  The present invention is capable of stably circulating a coating liquid containing high viscosity or particles in a coating liquid pan without causing precipitation of particles or the like with respect to a coating liquid pan of a gravure coating machine. It is an object of the present invention to provide a coating liquid circulation device and a coating liquid circulation method.

The invention according to claim 1 of the present invention is a coating liquid pan provided in a coating apparatus for applying a coating liquid to a strip-shaped substrate conveyed in the longitudinal direction, and repeatedly supplying and discharging the coating liquid, A coating liquid circulation device for circulation,
A plurality of coating liquid supply ports that are formed on the side surface of the coating liquid pan along the width direction of the base material and supply the coating liquid into the coating liquid pan;
A plurality of coating liquid discharge ports that are formed on the bottom surface of the coating liquid pan along the width direction of the base material and discharge the coating liquid from the coating liquid pan;
A coating liquid outlet opening / closing means disposed below the coating liquid outlet and opening and closing the coating liquid outlet;
A coating liquid collecting pan that is disposed below the coating liquid discharge port opening and closing means and collects the coating liquid;
Coating liquid supply means for supplying the coating liquid into the coating liquid pan; and coating liquid recovery means for returning the coating liquid discharged from the coating liquid recovery pan to a coating liquid tank. This is a coating liquid circulation device characterized by the above.

The invention according to claim 2 of the present invention is characterized in that the coating liquid outlet opening / closing means automatically opens and closes according to the amount of the coating liquid in the coating liquid pan. Coating liquid circulation device.

  The invention according to claim 3 of the present invention is characterized in that the coating liquid discharge port is a parallel slit in the same direction as the longitudinal direction of the base material. Device.

  The invention according to claim 4 of the present invention is characterized in that the coating liquid discharge port opening / closing means is arranged so as to be in contact with the bottom surface of the coating liquid pan and has a slit formed therein. It is a coating liquid discharge control plate having the same shape as the bottom surface and provided with a plurality of slits at positions not in contact with the coating liquid discharge port, the bottom surface of the coating liquid pan and the coating liquid discharge control plate The coating liquid circulating apparatus according to any one of claims 1 to 3, wherein the coating liquid is discharged by opening a gap.

  According to a fifth aspect of the present invention, the amount of the coating liquid in the coating liquid pan is detected by a load sensor or a pressure sensor, and the opening / closing operation of the coating liquid discharge opening / closing means is automatically controlled. It is a coating-liquid circulation apparatus of any one of Claim 1 to 4 characterized by the above-mentioned.

  The invention according to claim 6 of the present invention is characterized in that the coating liquid supply means and the coating liquid recovery means comprise a volume rotary pump or a volume reciprocating pump. It is a coating-liquid circulation apparatus of any one of Claims.

  Invention of Claim 7 of this invention is a coating liquid circulation method characterized by circulating a coating liquid using the coating liquid circulation apparatus of any one of Claim 1 to 6. .

  The invention according to claim 8 of the present invention is characterized in that the coating liquid is applied to the substrate using the coating liquid circulation device according to any one of claims 1 to 6. It is a manufacturing method of a workpiece.

  According to the first aspect of the present invention, the plurality of coating liquid supply ports are arranged along the width direction of the base material on the side surface of the coating liquid pan. For this reason, even when the coating liquid has a high viscosity, it is possible to supply the coating liquid supplied from the coating liquid supply port uniformly to the coating liquid pan along the width direction of the substrate. Become. Further, a plurality of coating liquid discharge ports are arranged along the width direction of the base material on the bottom surface of the coating liquid pan. For this reason, even when the coating liquid contains particles or the like, it becomes possible to discharge the coating liquid from the coating liquid pan without settling the particles or the like at the bottom of the coating liquid pan. The liquid can be circulated with a constant viscosity and a uniform state.

  According to the invention of claim 2, the coating liquid discharge port opening / closing means automatically opens and closes according to the amount of the coating liquid in the coating liquid pan. For this reason, when the coating liquid in the coating liquid pan is small and insufficient to circulate, the coating liquid discharge port is closed, and the coating liquid pan is filled with the coating liquid. When circulation is required, the coating liquid discharge port automatically opens, preventing the coating liquid from being discharged more than necessary and preventing the coating liquid from overflowing from the coating liquid pan. Also, if the coating liquid is continuously supplied stably, the coating liquid is circulated stably, and the coating liquid in the coating liquid pan can be maintained at a constant amount, and the stable coating is performed. It is possible to obtain a good coated product.

According to the invention of claim 3, a plurality of coating liquid discharge ports arranged along the width direction of the base material on the bottom surface of the coating liquid pan are parallel slits in the same direction as the longitudinal direction of the base material. is there. For this reason, the coating liquid in the coating liquid pan is not discharged in a large amount at a time, and the flow of the coating liquid caused by the rotation of the gravure plate cylinder immersed in the coating liquid in the coating liquid pan Along with this, it becomes possible to discharge slowly. Furthermore, the coating liquid in the coating liquid pan is uniformly discharged without staying in the coating liquid pan, so even a coating liquid containing high viscosity or particles should be discharged in a stable state. Can do.

  According to the invention of claim 4, as the coating liquid discharge port opening and closing means, the same shape as the bottom surface of the coating liquid pan, which is arranged in contact with the bottom surface of the coating liquid pan so that there is no gap, and in which a slit is formed. The coating liquid discharge port opening / closing plate is used to automatically open and close the gap between the bottom surface of the coating liquid pan and the coating liquid discharge control plate, thereby controlling the discharge of the coating liquid. For this reason, opening and closing of the coating liquid discharge port can be performed only by the vertical movement of the coating liquid discharge control plate, which is simple. In addition, there is a gap from the coating solution discharge port to the coating solution discharge control plate, and the coating solution passes from the coating solution discharge port to the coating solution discharge control plate and is further formed on the coating solution discharge control plate. The coating liquid does not flow directly from the coating liquid discharge port into the coating liquid recovery pan through the slit, and the coating liquid containing high viscosity or particles is not uniform. Can be prevented.

  According to the invention of claim 5, the coating liquid is supplied into the coating liquid pan, and the amount is sufficient to supply the coating liquid to the gravure plate cylinder, and the amount does not overflow from the coating liquid pan. Is set as the upper limit of the coating liquid volume, and the load sensor or pressure sensor is set to detect the upper limit of the coating liquid volume, so that a signal for opening the coating liquid discharge port is sent from the load sensor or pressure sensor. Then, the coating liquid discharge port is opened and the coating liquid is discharged. Also, even during the coating work in which the coating liquid is circulated, if the supply of the coating liquid is insufficient and the amount of the coating liquid in the coating liquid pan decreases, the lower limit of the coating liquid amount A signal for closing the coating liquid discharge port is sent from the load sensor or pressure sensor, and the coating liquid discharge port closes to suppress the decrease in the coating liquid in the coating liquid pan, and the gravure plate cylinder Prevents the coating liquid from being supplied uniformly and sufficiently.

  According to invention of Claim 6, the coating liquid supply means which supplies a coating liquid in a coating liquid pan, and the coating liquid collection | recovery which returns the coating liquid discharged | emitted from the coating liquid pan to a coating liquid tank The means comprises a positive displacement pump or positive displacement pump. For this reason, it becomes possible to easily perform the operation of supplying the coating liquid into the coating liquid pan and returning the coating liquid discharged from the coating liquid pan to the coating liquid tank.

According to the invention of claim 7, the plurality of coating liquid supply ports are arranged along the width direction of the substrate.
For this reason, even when the coating liquid has a high viscosity, it is possible to supply the coating liquid supplied from the coating liquid supply port uniformly to the coating liquid pan along the width direction of the substrate. Become. Further, a plurality of coating liquid discharge ports are arranged along the width direction of the base material on the bottom surface of the coating liquid pan. For this reason, even when the coating liquid contains particles or the like, it becomes possible to discharge the coating liquid from the coating liquid pan without settling the particles or the like at the bottom of the coating liquid pan. The liquid can be circulated with a constant viscosity and a uniform state.

  According to the invention of claim 8, the coating liquid containing high viscosity in the coating liquid pan or containing particles and the like is continuously maintained in a state where a uniform amount is circulated without maintaining the uniform viscosity and settling the particles and the like. It is possible to apply the coating liquid to the substrate that is being transported in an automatic manner. For this reason, it becomes possible to improve the quality of the coating film formed by apply | coating a coating liquid to a base material, and can manufacture a high quality coated material.

  The coating liquid circulation device of the present invention is capable of circulating a certain amount of coating liquid containing high viscosity or particles in the coating liquid pan without maintaining the uniform viscosity and settling the particles. It becomes possible to supply a uniform coating liquid into the working liquid pan, and it is possible to suppress the occurrence of coating defects.

It is explanatory drawing which shows an example of the coating liquid circulation apparatus of this invention. It is explanatory drawing which shows an example of the coating liquid circulation apparatus of this invention. It is explanatory drawing which shows an example of the coating liquid circulation apparatus in general gravure coating.

  Hereinafter, the configuration of the coating liquid circulation device 1 of the present embodiment will be described with reference to FIGS. 1 and 2 for the first embodiment of the present invention (hereinafter referred to as the present embodiment).

  FIG. 1 is a cross-sectional view showing a schematic configuration of a coating liquid circulation device 1 of the present invention, and FIG. 2 is a perspective view. 1 and 2, the same reference numerals are given to the same components as those of the coating liquid circulation device 1 shown in FIG.

  The coating liquid circulation device 1 is a device that repeatedly circulates the supply and discharge of the coating liquid in a coating liquid pan provided in a coating apparatus that applies the belt-shaped substrate conveyed in the longitudinal direction. As shown in FIG. 1, the lower part of the gravure plate cylinder 24 is immersed in the coating liquid 2 supplied into the coating liquid pan 4.

  In this embodiment, the case where a base material is a strip | belt-shaped film is demonstrated as an example.

  In the present embodiment, as an example, a case of a liquid that is a high-viscosity coating agent including particles in which the coating liquid 2 is dispersed will be described.

  The coating liquid 2 used in the coating liquid circulation apparatus 1 of the present embodiment preferably has a viscosity of about 500 to 10,000 {mPa · s}, for example. This is because, in the case of the coating liquid 2 having a viscosity of less than 500 {mPa · s}, the viscosity of the coating liquid pan 4 is less likely to be biased. In the case of the coating liquid 2 having a viscosity greatly exceeding 10,000 {mPa · s}, it may be difficult to circulate while keeping the viscosity and the dispersion state of the particles uniform. Is high. However, the coating liquid 2 used for the coating liquid circulation apparatus 1 of the present embodiment is not particularly limited.

  The coating liquid pan 4 is formed in a box shape having an open top, and a plurality of coating liquid discharge ports 10 are formed on the bottom surface. As shown in FIG. 1, the coating liquid circulation device 1 includes a plurality of coating liquid supply ports 8, a coating liquid discharge control plate 12, a coating liquid discharge plate driving device 13, and a coating liquid collection pan. 16, a load sensor 22, a coating liquid supply means, and a coating liquid recovery means.

  The plurality of coating liquid supply ports 8 are formed on the side surface of the coating liquid pan 4 and allow the coating liquid to flow into the coating liquid pan.

  The amount of the coating liquid 2 supplied into the coating liquid pan 4 is equal to or larger than the amount sufficiently supplied to the gravure plate cylinder 24 and the amount that does not overflow from the coating liquid pan 4 is 2 The load sensor 22 is set to detect the upper limit of the coating liquid 2 amount. The position of the load sensor 22 is at or near the bottom surface of the coating liquid pan 4 as long as it is not in contact with the gravure plate cylinder 24, the coating liquid supply port 8, and the coating liquid discharge port 10. Good. The sensor for detecting the amount of coating liquid 2 may be a pressure sensor or an ultrasonic sensor, and the selection of the sensor is not limited to this.

Further, in order to prevent the coating liquid 2 from being uniformly and sufficiently supplied to the gravure plate cylinder 24, a lower limit of the amount of the coating liquid in the coating liquid pan 4 is also determined and set so that the load sensor 22 can detect it. The lower limit of the amount of the coating liquid 2 is desirably 5 to 10% less than the upper limit of the amount of the coating liquid 2, but depends on the viscosity of the coating liquid 2 and the cell volume of the gravure plate cylinder 24. There is no particular limitation.

  A plurality of coating liquid discharge ports 10 are formed on the bottom surface of the coating liquid pan 4. In the present embodiment, as an example, as shown in FIG. 2, the coating liquid discharge port 10 is a parallel slit in the same direction as the longitudinal direction of the substrate. The number of coating liquid discharge ports 10 is determined by the physical properties of the coating liquid 2. Specifically, at least three or more are preferable, and it is more preferable that the coating liquid 2 has a higher viscosity. Furthermore, the distance between the coating liquid discharge ports 10 is preferably shorter than the length obtained by dividing the length in the width direction of the coating liquid pan 4 into four equal parts, but is not limited thereto.

  Here, when arranging the plurality of coating liquid discharge ports 10 along the width direction of the base material, the bottom surface of the coating liquid pan 4 is applied along the direction parallel to the width direction of the base material. It is preferable to arrange them at intervals equally divided by the number of the working fluid supply ports 10. However, the arrangement state of the plurality of coating liquid supply ports 10 is not limited to this. Moreover, although the bottom face of the coating liquid pan 4 is formed of stainless steel, it may be processed with fluororesin.

  A coating liquid discharge control plate 12 is disposed below the coating liquid pan 4, and is parallel to the coating liquid discharge control plate 12 in the same direction as the longitudinal direction of the base material. A plurality of slits 14 are formed at positions not in contact with 10. The coating liquid discharge control plate 12 is in contact with the lower part of the coating liquid pan 4 without a gap, and prevents the coating liquid 2 from flowing out from the coating liquid discharge port 10. The coating liquid discharge control plate 12 is connected to the coating liquid pan 4 and the coating liquid discharge plate driving device 13.

  The coating liquid discharge plate driving device 13 is a device that is driven by electricity or compressed air. However, the selection of the device for forming the coating liquid discharge plate driving device 13 is not limited to this as long as the device operates by receiving an electrical signal from the load sensor. Further, the coating liquid discharge control plate 12 descends when discharging the coating liquid 2, and creates a space between the bottom surface of the coating liquid pan 4. This space is large enough to flow into the slit 14 while keeping the viscosity of the coating liquid 2 and the dispersed state of the particles constant. Specifically, when the coating liquid 2 contains high viscosity or particles, the distance between the bottom surface of the coating liquid pan 4 and the coating liquid control plate is preferably about 5 to 10 mm. However, the present invention is not limited to this.

  Here, when arranging the plurality of slits 14 along the width direction of the substrate, the coating liquid discharge control plate 12 is moved along a direction parallel to the width direction of the coating liquid discharge control plate 12. It is preferable to arrange them at intervals equally divided by the number of slits 14 and to arrange them at positions where the coating liquid discharge port 10 and the slits 14 do not contact. However, the arrangement state of the plurality of slits 14 is not limited to this. The number of slits 14 is determined by the physical properties of the coating liquid 2. Specifically, at least two or more are preferable, and it is more preferable that the coating liquid 2 has a higher viscosity. Furthermore, the interval between the slits 14 is preferably shorter than the length obtained by dividing the length of the coating liquid pan 4 in the width direction into three equal parts, but is not limited thereto. Further, the coating liquid discharge control plate 12 is formed of stainless steel, but may be processed with fluororesin.

  The length of the coating liquid discharge port 10 (slit in the present embodiment) and the slit 14 is such that the coating liquid 2 can pass through without a delay due to gravity and the flow of the coating liquid 2 in the coating liquid pan 4. However, it is necessary to set the size so that the flow during the passage is fast and the dispersion state of the particles in the coating liquid 2 is not biased. As an example, when the viscosity of the coating liquid 2 is about 5000 {mPa · s}, about 10 to 20 mm is desirable. However, the length of the coating liquid discharge port 10 and the slit 14 is not limited to this. The lengths of the coating liquid discharge port 10 and the slit 14 are desirably unified, but are not limited thereto.

A coating liquid recovery pan 16 is disposed below the coating liquid discharge control plate 12 and is connected to the coating liquid recovery pipe 20. The bottom surface of the coating liquid recovery pan 16 is not horizontal but is formed by four inclined surfaces so that the coating liquid 2 that has passed through the coating liquid discharge port 10 and the slit 14 flows into the coating liquid discharge collection pipe 20. Yes. Moreover, although the coating liquid collection | recovery pan 16 is formed with stainless steel, it may be fluororesin processed.

  The coating liquid supply means is an unillustrated coating liquid supply pump (see FIG. 3), and is formed with a positive displacement rotary pump or a positive displacement reciprocating pump. The coating liquid supply pump 32 is a pump capable of sucking and discharging the coating liquid 2. The coating liquid supply pump 32 sucks the coating liquid 2 stored in the coating liquid tank 30 and applies the coating liquid supply pipe 18 and the coating liquid. The liquid is supplied into the coating liquid pan 4 through the liquid supply port 8.

  The coating liquid recovery means is a coating liquid recovery pump (see FIG. 3) that is not shown, and is provided with a volume rotary pump or a volume reciprocating pump. The coating liquid recovery pump 34 is a pump capable of sucking and discharging the coating liquid 2, and sucks the coating liquid 2 discharged from the coating liquid pan 4 through the coating liquid recovery pipe 20 to apply the coating liquid 2. Return to the working fluid tank 30.

  Accordingly, the coating liquid 2 is supplied from the coating liquid tank 30 through the coating liquid supply pump 32 to the coating liquid supply pipe 18, the coating liquid supply port 8, the coating liquid pan 4, and the coating liquid discharge port 10. The coating liquid discharge control plate 12, the slit 14, the coating liquid recovery pan 16, the coating liquid recovery pipe 20, and the coating liquid recovery pump 34 are circulated.

  Next, the coating liquid circulation method of this embodiment will be described with reference to FIGS.

  In the coating liquid circulation method of the present embodiment, in the coating liquid pan provided in the coating apparatus for applying the coating liquid to the belt-shaped substrate conveyed in the longitudinal direction, supply and discharge of the coating liquid are repeated, It is a method to circulate.

  Specifically, the coating liquid 2 stored in the coating liquid tank 30 is supplied from the coating liquid supply port 8 formed on the side surface of the coating liquid pan 4 via the coating liquid supply pump 32. It is discharged from a plurality of coating liquid discharge ports 10 formed on the bottom surface of the coating liquid pan 4 and parallel to the longitudinal direction of the base material, passes through the coating liquid discharge control plate 12 and the slit 14, and further, the coating liquid By reaching the recovery pan 16 (the flow of the coating liquid is A) and returning it to the coating liquid tank 30 via the coating liquid recovery pump 34, the high viscosity or particles in the coating liquid pan 4 are removed. This is a method of circulating a certain amount of the coating liquid 2 containing the coating liquid 2 while maintaining a uniform viscosity and without causing particles to settle.

  Next, with reference to FIGS. 1-3, the manufacturing method of the coated material using the coating liquid circulation apparatus 1 of this embodiment is demonstrated.

  In the method of manufacturing a coated product using the coating liquid circulation device 1 of the present embodiment, the coating liquid 2 is applied to the substrate 36 that is continuously conveyed, and the coating film is formed of the coating liquid 2. Is formed on the substrate 36 to produce a coated product. A uniform coating film can be obtained stably.

  Next, the operation of this embodiment will be described with reference to FIGS.

  The coating liquid 2 in the coating liquid tank 30 is supplied into the coating liquid pan 4 via the coating liquid supply pump 32. When the supply amount of the coating liquid 2 reaches the upper limit set in the load sensor 22, an electric signal is automatically sent to the coating liquid discharge plate driving device 13, and the coating liquid discharge plate driving device. By operating 13, the coating liquid discharge control plate 12 is lowered to form a gap with the bottom surface of the coating liquid pan 4. Thereby, the coating liquid 2 flows out from the slit 14 to the coating liquid recovery pan through the coating liquid discharge port 10 and the coating liquid discharge control plate 12 as shown in the flow A of the coating liquid.

At this time, the coating liquid 2 is discharged from a plurality of coating liquid discharge ports 10 (slits in the present embodiment) formed by being arranged on the bottom surface of the coating liquid pan along the width direction of the substrate. Thus, even if the coating liquid 2 contains dispersed particles, the dispersed state of the particles in the discharged coating liquid 2 does not become uniform. Moreover, since the coating liquid 2 is discharged without stagnation, its viscosity does not increase.

  Here, most of the coating liquid 2 made of a high-viscosity material in which particles are dispersed is a non-Newtonian fluid whose viscosity changes when a shearing force is applied. In particular, many of the coating liquids 2 exhibit so-called thixotropic properties in which the internal structure is broken and softened to increase fluidity when force is applied. Accordingly, the high-viscosity coating liquid 2 is applied to the coating liquid discharge port 10 (slit in this embodiment) that is a narrow gap, the gap between the bottom of the coating liquid pan 4 and the coating liquid discharge control plate 12, and The shearing force applied by passing through the slit 14 reduces the viscosity.

  For this reason, the coating liquid 2 flows into the coating liquid recovery pan while spreading uniformly in the longitudinal direction and the width direction of the base material of the coating liquid pan 4. Further, since the coating liquid 2 sucked from the coating liquid tank 30 by the coating liquid supply pump 32 is continuously supplied to the coating liquid supply pipe 18, the coating liquid supplied into the coating liquid pan 4 is supplied. Similarly, the liquid 2 is continuously supplied in a constant amount, and the coating liquid recovery pump 34 continues to return the recovered coating liquid 2 to the coating liquid tank 30 by a predetermined amount.

  Therefore, it is possible to circulate a certain amount of the coating liquid 2 containing high viscosity or particles in the coating liquid pan 4 without maintaining the uniform viscosity and settling the particles.

  Hereinafter, specific examples of the present invention will be described.

  The embodiment of the present invention is as shown in FIGS. 1 and 2, and the coating liquid 2 stored in the coating liquid tank 30 is applied to the side surface of the coating liquid pan 4 via the coating liquid supply pump 32. Supply from the formed coating liquid supply port 8, discharge from a plurality of coating liquid discharge ports 10 formed on the bottom surface of the coating liquid pan and parallel to the longitudinal direction of the substrate, and a coating liquid discharge control plate 12 and the slit 14, further reach the coating liquid recovery pan 16, and return to the coating liquid tank 30 via the coating liquid recovery pump 34, whereby the coating liquid 2 is circulated. Yes.

  In the present embodiment, the coating agent in which the titanium oxide particles are dispersed in the coating liquid tank 30 is supplied into the coating liquid pan 4 via the coating liquid supply pump 32. The coating liquid pan 4 is made of stainless steel, and the size of the bottom surface is 500 mm in the longitudinal direction of the base material 36 and 1400 mm in the width direction, and the depth of the coating liquid pan 4 is 250 mm.

  In this embodiment, the upper limit of the amount of the coating liquid 2 in the coating liquid pan 4 is set to the point where the liquid surface of the coating liquid 2 reaches a position 220 mm in height from the bottom surface of the coating liquid pan 4. The lower limit of the amount of the coating liquid 2 was set as the point at which the liquid surface of the coating liquid 2 decreased from the bottom surface of the coating liquid pan 4 to a position 210 mm in height.

  Next, the coating liquid 2 was supplied from the coating liquid tank 30 to the coating liquid pan 4 via the coating liquid supply pump 32 and the coating liquid supply pipe 18. The coating liquid supply ports 8 have a circular shape with a diameter of about 50 mm, and five are arranged in a straight line along the width direction of the base material 36 on the side surface of the coating liquid pan. The coating liquid 2 was supplied into the coating liquid pan 4 while being uniformly spread.

When the inside of the coating liquid pan 4 is filled with the coating liquid 2 and reaches the upper limit of the amount of coating liquid 2 set in advance, the load sensor 22 operates and sends an electrical signal to the coating liquid discharge control plate driving device 13. As a result, the coating liquid discharge control plate driving device 13 driven by electricity is activated to automatically apply the coating liquid discharge control plate 12.
Fell. As a result, a gap was formed between the bottom surface of the coating liquid pan 4 and the coating liquid discharge control plate 12, and the coating liquid 2 was discharged from the coating liquid discharge port 10. The coating liquid discharge control plate 12 is made of a stainless steel surface processed with a fluororesin in order to facilitate cleaning of the coating liquid 2 after completion of the coating operation.

  Here, in the present embodiment, the coating liquid discharge ports 10 are slits of 400 mm in the longitudinal direction of the base material 36 and 10 mm in the width direction, and six are arranged on a straight line along the width direction. The interval between the coating liquid discharge ports 10 was 180 mm. In addition, when the coating liquid discharge control plate driving device 13 is operated, the distance by which the coating liquid discharge control plate 12 is lowered is such that the gap between the bottom surface of the coating liquid pan 4 and the coating liquid discharge control plate 12 is 10 mm. The slit 14 was 400 mm in the longitudinal direction of the substrate 36 and 10 mm in the width direction, like the coating liquid discharge port 10. Five were arranged on a straight line along the width direction so that the interval between the slits 14 was 180 mm.

  As shown in the flow A of the coating liquid, the coating liquid 2 is discharged from the coating liquid discharge port 10 and passes through the gap between the bottom surface of the coating liquid pan 4 and the coating liquid discharge control plate 12 and the slit 14. And flowed into the stainless steel coating liquid recovery pan 16. At this time, the coating liquid 2 is given a shearing force by passing through a narrow gap, its viscosity is lowered, and the coating liquid is spread uniformly in the longitudinal direction and the width direction of the base material of the coating liquid pan 4. It flowed into the collection pan 16. Further, the titanium oxide particles dispersed in the coating liquid 2 were also discharged without settling.

  The coating liquid 2 collected by the coating liquid collection pan 16 passed through the coating liquid collection pipe 20 and returned to the coating liquid tank 30 via the coating liquid collection pump 34. Even at that time, the coating liquid 2 in the coating liquid tank 30 was continuously supplied to the coating liquid pan 4 by the coating liquid supply pump 32. The time required for the circulating coating liquid 2 to be sucked up from the coating liquid tank 30 by the coating liquid supply pump 32 and return to the coating liquid tank 30 from the coating liquid supply pump 32 is about 3 minutes. Met.

  When the viscosity and specific gravity of the coating liquid 2 in the coating liquid tank 30 were measured while being circulated in this manner, the coating liquid 2 after 30 minutes from the start of circulation of the coating liquid 2 has a viscosity and specific gravity. In both cases, the initial viscosity was 7000 {mPa · s} and the specific gravity was 1.30.

  Therefore, in this embodiment, it is possible to circulate a certain amount of the coating liquid 2 containing high viscosity or particles in the coating liquid pan 4 without maintaining the uniform viscosity and settling the particles. .

  The coating liquid circulation device and the coating liquid circulation method of the present invention are inventions that can be used in a wide range of fields such as machines for producing high-viscosity materials such as adhesives or machines for producing and processing pasty foods. .

DESCRIPTION OF SYMBOLS 1 Coating liquid circulation apparatus 2 Coating liquid 4 Coating liquid pan 6 Weir 8 Coating liquid supply port 10 Coating liquid discharge port 12 Coating liquid discharge control board 13 Coating liquid discharge control board drive device 14 Slit 16 Coating Liquid recovery pan 18 Coating liquid supply pipe 20 Coating liquid recovery pipe 22 Load sensor 24 Gravure plate cylinder 26 Doctor blade 28 Impression cylinder 30 Coating liquid tank 32 Coating liquid supply pump 34 Coating liquid recovery pump 36 Base material A Coating Working fluid flow

Claims (8)

In the coating liquid pan provided in the coating apparatus that applies the coating liquid to the strip-shaped substrate conveyed in the longitudinal direction, a coating liquid circulation apparatus that repeatedly circulates the supply / discharge of the coating liquid,
A plurality of coating liquid supply ports that are formed on the side surface of the coating liquid pan along the width direction of the base material and supply the coating liquid into the coating liquid pan;
A plurality of coating liquid discharge ports that are formed on the bottom surface of the coating liquid pan along the width direction of the base material and discharge the coating liquid from the coating liquid pan;
A coating liquid outlet opening / closing means disposed below the coating liquid outlet and opening and closing the coating liquid outlet;
A coating liquid collecting pan that is disposed below the coating liquid discharge port opening and closing means and collects the coating liquid;
Coating liquid supply means for supplying the coating liquid into the coating liquid pan; and coating liquid recovery means for returning the coating liquid discharged from the coating liquid recovery pan to a coating liquid tank. A coating liquid circulation device characterized by that.   2. The coating liquid circulation apparatus according to claim 1, wherein the coating liquid discharge port opening / closing means automatically opens and closes according to the amount of the coating liquid in the coating liquid pan.   The coating liquid circulation device according to claim 1, wherein the coating liquid discharge port is a parallel slit in the same direction as the longitudinal direction of the substrate.   The coating liquid discharge port opening / closing means is arranged in contact with the bottom surface of the coating liquid pan so as not to have a gap, and has the same shape as the bottom surface of the coating liquid pan in which a slit is formed. A coating liquid discharge control plate having a plurality of slits provided at positions not in contact with the liquid discharge port, and discharging the coating liquid by opening a gap between the bottom surface of the coating liquid pan and the coating liquid discharge control plate. The coating liquid circulation device according to any one of claims 1 to 3, wherein the coating liquid circulation device is provided.   The amount of the coating liquid in the coating liquid pan is detected by a load sensor or a pressure sensor, and the opening / closing operation of the coating liquid discharge opening / closing means is automatically controlled. The coating liquid circulation device according to claim 1.   The coating liquid circulation according to any one of claims 1 to 5, wherein the coating liquid supply means and the coating liquid recovery means include a volume rotary pump or a volume reciprocating pump. apparatus.   A coating liquid circulation method comprising circulating the coating liquid using the coating liquid circulation device according to claim 1.   A method for producing a coated product, wherein the coating liquid is applied to the substrate using the coating liquid circulation device according to any one of claims 1 to 6.

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