JP2004223391A - Coating device and coating method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating device capable of inhibiting generation of coating defect on a film by inhibiting entanglement of a foam into a coating liquid having adjusted coating thickness, and a coating method using it. <P>SOLUTION: The coating device 11 is provided with a coating mechanism 13 for excessively coating the coating liquid 17 against a coating amount after the coating thickness is adjusted; and a coating thickness adjustment mechanism 14 provided at a downstream side of the coating mechanism 13 and adjusting the coating thickness of the coating liquid 17 excessively coated. The coating thickness adjustment mechanism 14 has a bar 22 for adjusting the coating thickness pressed to a surface of a film 16 at a side where the coating liquid 17 is excessively coated. A foam entangling inhibition member 34 for inhibiting entanglement of the foam into the coating liquid 17 is inserted from a downstream side of the bar 22 for adjusting the coating thickness between the bar 22 for adjusting the coating thickness and the film 16. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a coating apparatus used when applying a coating liquid to a film such as a polyester film that runs continuously, and a coating method using the same. More specifically, the present invention relates to a coating apparatus capable of suppressing generation of coating defects on a film by suppressing air bubbles from being trapped in a coating liquid whose coating thickness has been adjusted, and a coating method using the same.
[0002]
[Prior art]
Conventionally, a coating apparatus that applies a coating liquid to the lower surface of a film such as a polyester film that travels continuously is a precoat apparatus that applies a precoat liquid to the lower surface of the film to improve the applicability of the coating liquid to the lower surface of the film. And a column-shaped applicator roll that is located on the downstream side and applies a coating liquid to the lower surface of the film. Both ends of the applicator roll are formed in a tapered shape whose diameter is reduced toward the end, and gravure cells are formed in the outer peripheral surface thereof as diagonal grooves which are inclined in the running direction of the film toward the end. ing. The applicator roll is configured to rotate so as to face the running direction of the film and to be pressed against the film from below (for example, see Patent Document 1).
[0003]
Then, after applying the precoat liquid to the lower surface of the film using a precoat apparatus, the precoat liquid is scraped off on the upstream side and the coating liquid is applied on the downstream side using an applicator roll. Here, when air bubbles are present in the precoat liquid applied to the lower surface of the film, the air bubbles are expelled outward from the end of the applicator roll by the gravure cell when the applicator roll scrapes off the precoat liquid. Therefore, air bubbles in the pre-coat liquid move around the end of the applicator roll as the film travels and move into the coating liquid on the downstream side. This prevents the occurrence of coating defects.
[0004]
In addition, the coating device includes a coating mechanism that applies an excessive amount of the coating solution to the coating amount after the coating thickness is adjusted on the lower surface of the film, and a coating thickness adjustment that adjusts the coating thickness of the coating solution that is excessively applied. Some include a mechanism (for example, see Patent Document 2). This coating apparatus is disposed below a film continuously running by a plurality of transport rollers such that the coating mechanism is located on the upstream side and the coating thickness adjusting mechanism is located on the downstream side. The coating thickness adjusting mechanism has a coating thickness adjusting bar having a circular cross section, and the film is pushed up by pressing the coating thickness adjusting bar from below onto a film on which the coating liquid is excessively applied to the lower surface by the coating mechanism. Then, an excess amount of the coating liquid is scraped off to adjust the coating thickness of the coating liquid.
[0005]
[Patent Document 1]
JP-A-2001-900 (pages 2 to 4)
[Patent Document 2]
JP 2001-145846 A (pages 2 to 5)
[0006]
[Problems to be solved by the invention]
However, in the former coating apparatus, the gravure cells recessed on the outer peripheral surfaces at both ends of the applicator roll prevent air bubbles from being drawn into the coating liquid from outside when the coating liquid is coated on the lower surface of the film. There was a problem that it could not be suppressed.
[0007]
On the other hand, in the latter coating device, when the coating thickness adjusting bar scrapes off the excess coating solution, a part of the excess coating solution is partially removed on the upstream side of the tangent line between the coating thickness adjusting bar and the film. , The coating width of the coating liquid on the film is widened. For this reason, on the upstream side of the tangent line between the coating thickness adjusting bar and the film, the application width of the coating liquid to the film is widened, so that it is possible to suppress the incorporation of bubbles into the coating liquid from outside. However, on the downstream side of the tangent line between the coating thickness adjusting bar and the film, there is a problem that air bubbles cannot be suppressed from being incorporated into the coating liquid whose coating thickness has been adjusted.
[0008]
The present invention has been made by paying attention to the problems existing in the prior art as described above. An object of the present invention is to provide a coating apparatus and a coating method using the coating apparatus, which can suppress the generation of coating defects on a film by suppressing entanglement of bubbles in a coating liquid having a controlled coating thickness. It is in.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the coating apparatus according to the first aspect of the present invention applies a coating liquid to a surface of a continuously running film in excess of a coating amount after a coating thickness is adjusted. And a coating thickness adjustment mechanism provided downstream of the coating mechanism for adjusting the coating thickness of the excessively applied coating solution. It has a coating thickness adjustment bar with a circular cross section that adjusts the coating thickness by being pressed against the surface of the coated film, and between the coating thickness adjustment bar and the film, bubbles of the coating solution are formed. A bubble entrainment suppressing member for suppressing entrainment is inserted from the downstream side of the coating thickness adjusting bar.
[0010]
According to a second aspect of the present invention, in the first aspect of the present invention, the bubble entrainment suppressing member is applied to the film and is positioned at positions corresponding to both ends of the application liquid whose application thickness is adjusted. To suppress the entrapment of air bubbles from both ends.
[0011]
According to a third aspect of the present invention, in the first aspect or the second aspect of the invention, the bubble entrainment suppressing member is formed to be narrower toward the front end and the front end is different. It is embedded.
[0012]
According to a fourth aspect of the present invention, in the coating apparatus according to any one of the first to third aspects, the coating liquid is applied to a film when the coating thickness is adjusted by a coating thickness adjusting bar. The coating width is widened, and a pair of the bubble entrainment suppressing members are inserted into positions corresponding to both ends of the coating liquid before the coating thickness is adjusted.
[0013]
According to a fifth aspect of the invention, there is provided a coating method using the coating apparatus according to any one of the first to fourth aspects, wherein a coating mechanism adjusts a coating thickness on a surface of a continuously running film. After applying an excessive amount of the coating solution to the coating amount after being applied, while adjusting the coating thickness of the coating solution by pressing a coating thickness adjusting bar against the surface of the film on which the coating solution is excessively applied, The bubble entrainment suppressing member suppresses entrainment of air bubbles in the coating liquid.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
As shown in FIGS. 1A and 2, the coating device 11 is configured by mounting a coating mechanism 13 and a coating thickness adjusting mechanism 14 on a square plate-shaped base 12. The application device 11 includes an application mechanism 13 located upstream of a film 16 that continuously travels in the direction of the arrow A in FIG. 1A by a plurality of transport rollers 15, and an application thickness adjustment mechanism 14. It is arranged to be located on the downstream side. Then, a coating liquid 17 is applied to the center of the lower surface of the film 16 by the coating mechanism 13, and the coating thickness of the coating liquid 17 applied to the film 16 is adjusted by the coating thickness adjusting mechanism 14.
[0015]
The first base 18 constituting the coating mechanism 13 is formed in the shape of a quadrangular prism extending in the width direction of the film 16 and is installed on the base 12. A coating liquid storage groove 19 having a substantially circular cross section is provided at the center of the upper surface. It is recessed so as to extend in the width direction of the film 16. On the upper surface of the first base 18, a coating portion 20 having a pentagonal prism shape is formed, which is formed so as to be inclined so that the top surface becomes lower as it goes forward and backward.
[0016]
The top edge of the coating section 20 is slightly separated from the film 16, and a coating liquid spray groove 21 having a constant opening width is formed in the center thereof so as to extend in the width direction of the film 16. The coating liquid spray groove 21 communicates with the coating liquid storage groove 19 and is narrower toward the top.
[0017]
After the application liquid 17 is press-fitted into the application liquid storage groove 19 from the application liquid storage tank (not shown), the application liquid 17 is jetted from the upper end opening of the application liquid jet groove 21 toward the lower surface of the film 16. Thus, the coating liquid 17 is applied to the center of the lower surface of the film 16. The amount of the coating liquid 17 applied to the center of the lower surface of the film 16 is set excessively with respect to the application amount after the application thickness is adjusted by the application thickness adjusting mechanism 14. Further, when the coating liquid 17 drips from the lower surface of the film 16 to the top surface of the coating unit 20, it flows down from the top surface of the coating unit 20.
[0018]
As shown in FIG. 5, a coating thickness adjusting bar 22 (hereinafter, also simply referred to as a bar 22) constituting a coating thickness adjusting mechanism has a wire 22b wound around an outer peripheral surface of an intermediate portion of a cylindrical bar main body 22a. As a result, a circular cross section is formed. In the present embodiment, the bar body 22a has a diameter of 1 to 50 mm and a length of 0.5 to 2.5 m, and the wire 22b has a diameter of 50 to 150 μm. The bar body 22a and the wire 22b are each formed of a metal material such as stainless steel. In the drawings, the diameter of the wire 22b is exaggerated and exaggerated for easy understanding.
[0019]
As shown in FIG. 6, the surface of the wire 22b is covered with a wear modifying film 24 via an adhesion film 23. Then, the wear of the wire 22b is suppressed by the wear modifying film 24 to improve the durability of the bar 22, and the adhesion of the wear modifying film 24 to the wire 22b is improved by the adhesion film 23. As shown in FIG. 2, the end of the bar 22 is attached to a rotary drive device 25, and the bar 22 is rotated in the forward direction with respect to the running direction of the film 16, that is, in the direction of the arrow B in FIG. You.
[0020]
As shown in FIGS. 1A and 2, the second base 26 constituting the coating thickness adjusting mechanism 14 is formed in a rectangular column shape extending in the width direction of the film 16, and is installed on the base 12. A bar holder 27 having a substantially semi-cylindrical shape for supporting the bar 22 is attached to the upper surface of the second base 26.
[0021]
The bar holder 27 is formed of a synthetic resin material such as urethane resin or a metal material such as stainless steel, and has a bar support recess 28 having a semicircular cross section at the upper end so as to extend in the width direction of the film 16. . The bar 22 supported by the bar supporting recess 28 is pressed against the film 16 from below and rotated, thereby pushing up the film 16 and scraping off the excess coating liquid 17 to measure the coating amount. Adjust the thickness.
[0022]
A plurality of substantially circular cleaning grooves 29, one pair in this embodiment, are provided on the inner surface of the bar supporting recess 28, and a cleaning liquid such as water flows inside each cleaning groove 29. The surface of the wear modifying film 24 is cleaned by the cleaning liquid, and the wear modifying film 24, the wire 22b, and the like heated by the frictional heat generated by the sliding contact between the film 16 and the bar 22 are cooled. Between the upstream side surface of the first base 18 and the space between the bases 18 and 26, the coating solution 17 flowing down from the top surface of the coating unit 20 or the coating solution 17 scraped off from the film 16 by the bar 22. Each of the trays 30 is in the shape of a receiving tray for collecting the trays.
[0023]
As shown in FIGS. 2 to 4, on the base 12, on the downstream side of the coating thickness adjusting mechanism 14, a rectangular pillar-shaped support bar 31 extending in the width direction of the film 16 is supported by support legs 32 hanging down from both ends thereof. Supported. A pair of rectangular tubular positioning members 33 are fitted to the support rod 31 so as to be movable in the width direction of the film 16. On the downstream side surface of the support rod 31, a movement adjustment scale 35 for determining a movement position of a bubble entrapment suppressing member 34 (hereinafter, also simply referred to as a suppressing member 34) attached to each positioning member 33 is drawn. Have been.
[0024]
As shown in FIGS. 1B and 3, the suppressing member 34 is formed in a square plate shape, and the front end portion is formed in a plane isosceles triangle shape that becomes narrower toward the front end edge, and is bent. It extends obliquely upward with respect to the base end portion having a square plate shape. At four corners of a rectangular plate-shaped cover plate 36 corresponding to the upper wall of the positioning member 33 and the base end of the suppressing member 34, insertion holes 36a are formed to penetrate.
[0025]
Then, with the distal end of the suppressing member 34 located on the upstream side and the proximal end located on the downstream side, the proximal end of the suppressing member 34 is interposed between the upper wall of the positioning member 33 and the lid plate 36. I do. Next, the plurality of bolts 37 are inserted into the respective insertion holes 36a and then screwed into the upper wall of the positioning member 33 via the base end of the suppressing member 34, so that the suppressing member 34 is attached to the positioning member 33. Have been. Here, the tip of the suppressing member 34 is inserted between the bar 22 and the film 16 from the downstream side of the bar 22, and the tip edge is in contact with the bar 22 and the film 16.
[0026]
The positioning member 33 is configured such that a wing nut 33a is attached to a downstream side surface thereof, and the wing nut 33a is tightened and fixed to the support rod 31 by tightening the wing nut 33a.
[0027]
The suppressing member 34 is formed of a material having a hardness equal to or less than the material of the film 16 to be described later in order to prevent the film 16 from being damaged due to the contact of the leading edge thereof with the film 16. Preferably. Therefore, specific examples of the material of the suppressing member 34 include a synthetic resin material such as polyester.
[0028]
Here, as shown in FIG. 4, when the bar 22 scrapes off the excess coating solution 17, a part of the excess coating solution 17 is removed on the upstream side of the tangent 38 between the bar 22 and the film 16. Because of the movement toward the end, the application width of the application liquid 17 to the film 16 is increased. Further, the spread of the application width becomes maximum on the tangent line 38 between the bar 22 and the film 16.
[0029]
At this time, the amount of the coating liquid 17 that moves toward the edge of the film 16 decreases as it moves toward the edge of the film 16. For this reason, in the coating liquid 17 on the downstream side of the tangent line 38 between the bar 22 and the film 16, a region C in which the coating thickness is adjusted by the bar 22 is formed in a region corresponding to the coating width before the coating thickness is adjusted. Is done. Further, in both ends of the region C, that is, in a region where the coating width is widened with respect to the coating width before the coating thickness is adjusted, a region D in which the coating thickness becomes smaller and the coating thickness becomes non-uniform as approaching the end portion. It is formed.
[0030]
In this region D, as the width of application of the coating liquid 17 to the film 16 increases, the rotation of the bar 22 and the running of the film 16 cause air bubbles having a diameter of, for example, 0.1 to 0.2 mm into the coating liquid 17 from outside. Engulf. Then, the bubbles in the application liquid 17 in the region D move toward the center of the film 16 as the bar 22 rotates and the film 16 runs. For this reason, the leading edge of each suppression member 34 is located at a position corresponding to both ends of the region C in order to suppress the entrapment of air bubbles into the coating liquid 17 in the region C.
[0031]
By the way, in order to suppress the entrapment of air bubbles into the application liquid 17 in the region C, in addition to positioning the leading edge of each suppressing member 34 at a position corresponding to both ends of the region C, the outer peripheral surface of the bar 22 Preferably, the gap formed between the lower surface of the film 16 and the distal end surface of the suppressing member 34 is preferably reduced. That is, it is preferable to deepen the insertion of the tip of the suppressing member 34 between the bar 22 and the film 16. Here, when the insertion of the tip of the suppressing member 34 between the bar 22 and the film 16 is shallow, bubbles in the coating liquid 17 in the region D are generated by the outer peripheral surface of the bar 22 and the lower surface of the film 16. Move into the coating liquid 17 in the region C via a gap formed between the suppression member 34 and the tip end surface.
[0032]
Therefore, the thickness of the suppressing member 34 is preferably set to 50 to 100 μm, and more preferably 70 to 80 μm. When the thickness of the suppression member 34 is less than 50 μm, the flexibility of the suppression member 34 formed of a synthetic resin material or the like increases because the thickness of the suppression member 34 is small. The leading edge may be separated from the bar 22 and the film 16 by bending.
[0033]
On the other hand, if it exceeds 100 μm, the insertion of the distal end of the suppressing member 34 between the bar 22 and the film 16 becomes shallow, and the film 16 is pushed up by the distal end edge of the suppressing member 34, and the gap between the bar 22 and the film 16 is reduced. A gap is easily formed between them. For this reason, the excessive amount of the coating solution 17 scraped off by the bar 22 becomes insufficient, and the excess coating solution not scraped off by the bar 22 in the film 16 in which the coating thickness of the coating solution 17 is adjusted by the bar 22 is insufficient. 17 may cause a liquid flow. Further, when the film 16 coated with the coating liquid 17 is stretched and dried to form the film 16 coated with the coating film, the coating liquid 17 may be insufficiently dried and the coating film may be broken by stretching. .
[0034]
The depth of the insertion of the distal end of the restraining member 34 between the bar 22 and the film 16 is, in addition to the thickness of the restraining member 34, a plane passing through the distal end of the restraining member 34 and the base end thereof. , That is, the bending angle of the tip of the suppressing member 34 is a factor. For this reason, the bending angle is preferably set to 20 to 40 °, more preferably 25 to 35 °.
[0035]
When the bending angle is less than 20 °, the height of the support rod 31 needs to be increased because the bending angle of the tip of the suppressing member 34 is small, and the film 16 and the cover plate 36 come close to each other to And the cover plate 36 may come into contact. On the other hand, if it exceeds 40 °, the insertion of the distal end portion of the suppressing member 34 between the bar 22 and the film 16 may become shallow.
[0036]
In order to suppress the bending of the distal end portion of the suppressing member 34, it is preferable to set the thickness of the restricting member 34 to the above range and also to form the distal end portion of the suppressing member 34 small. For this reason, the distance between the film 16 and the cover plate 36 is preferably set to 20 to 40 mm, more preferably 25 to 35 mm.
[0037]
If the distance between the film 16 and the cover plate 36 is less than 20 mm, the coating liquid 17 may come into contact with the cover plate 36 due to the approach between the film 16 and the cover plate 36. On the other hand, when the distance exceeds 40 mm, the distance between the bar 22 and the film 16 and the distance between the base end of the suppression member 34 are increased, so that the distal end of the suppression member 34 needs to be formed large. May bend.
[0038]
Specific examples of the material of the film 16 include polyester such as polyethylene terephthalate (PET) and polyethylene naphthalate. The composition of the coating liquid 17 is determined depending on the use of the film 16 having the coating film coated on the surface. For example, when the film 16 having the coating film coated on the surface is used as a base film for printing, the coating liquid is titanium oxide ( TiO ₂ ) It contains pigments such as particles. The coating liquid 17 is preferably configured as an aqueous coating liquid so that even when the solvent evaporated during drying is discharged, the environment is not affected.
[0039]
Next, a method of applying the coating liquid 17 to the film 16 will be described. Here, the film 16 is formed as an unstretched film, and is subjected to a sequential biaxial stretching step of continuously performing a longitudinal stretching step and a transverse stretching step. The coating step on the film 16 includes a longitudinal stretching step and a transverse stretching step. It is applied between
[0040]
The film 16 is formed as an amorphous unstretched film by first cooling a melt-extruded polyester raw material on a rotary cooling drum. Subsequently, as the longitudinal stretching step, the peripheral speed is set higher as the group of rolls disposed to extend in the front-rear direction of the film 16, that is, the direction perpendicular to the longitudinal direction, is positioned at the front, and the film 16 is stretched vertically. Stretch in the direction (longitudinal stretching).
[0041]
Next, as shown in FIGS. 1A and 2, as a coating step, the film 16 is continuously run by a plurality of transport rollers 15. At this time, the film 16 generally has a width of 0.3 to 2.5 m and a thickness of 8 to 1200 μm. Then, the coating liquid 17 is applied to the lower surface of the film 16 in excess of the coating amount after the coating thickness is adjusted by the coating mechanism 13, and then the excess coating liquid 17 is applied by the bar 22 of the coating thickness adjusting mechanism 14. Is scraped off to adjust the coating thickness, and the coating liquid 17 is applied to the center of the lower surface of the film 16.
[0042]
Subsequently, as a transverse stretching step, the film 16 to which the coating solution 17 has been applied is held by clips, and is stretched (horizontal stretching) in a direction perpendicular to the longitudinal direction of the film 16 to obtain a biaxially stretched film. Here, for example, a film having a width of 1 to 2.5 m is horizontally stretched to a width of 8 m. The stretching temperature is preferably set to be gradually higher in order to prevent the surface of the coating solution 17 from being dried by rapidly heating the coating solution 17 and insufficient drying inside. Then, the biaxially stretched film is subjected to a heat treatment to produce a film 16 having a surface coated with a coating film. When heat-treating the biaxially stretched film, the film may be relaxed within 20%.
[0043]
When the application liquid 17 is applied to the center of the lower surface of the film 16 by the application device 11 in the application process, first, each positioning member 33 is positioned at a position where the leading edge of each suppression member 34 corresponds to both ends of the region C. Is slid on the support bar 31 so as to perform. Next, after the wing nuts 33 a are tightened and the respective positioning members 33 are tightened and fixed to the support rods 31, the coating liquid 17 is applied to the lower surface of the film 16 by the coating mechanism 13 and the coating liquid 17 is coated by the bar 22 of the coating thickness adjusting mechanism 14. Adjust the coating thickness.
[0044]
At this time, the tip of each restraining member 34 is inserted between the bar 22 and the film 16, and the tip edges are in contact with the bar 22 and the film 16, respectively. For this reason, as the width of application of the coating liquid 17 to the film 16 in the region D is widened, bubbles trapped in the coating liquid 17 from the outside are generated in the center of the film 16 with the rotation of the bar 22 and the running of the film 16. It moves toward and comes into contact with the leading edge of the suppressing member 34. The bubbles in the application liquid 17 in the region D are separated from the region C by separating the bubbles in contact with the leading edge of the suppressing member 34 from the region C along the side surface of the leading end of the suppressing member 34 as the film 16 travels. It is possible to prevent the C from moving into the coating liquid 17.
[0045]
According to the present embodiment described in detail above, the following effects are exhibited.
According to the coating device 11 of the present embodiment and the coating method using the same, the tip of the suppressing member 34 is inserted between the bar 22 and the film 16 from the downstream side of the bar 22. Therefore, by suppressing air bubbles from being trapped in the coating liquid 17 in the region C, that is, the coating liquid 17 whose coating thickness has been adjusted, the coating on the film 16 caused by the bubbles in the coating liquid 17 whose coating thickness has been adjusted. The occurrence of coating defects such as streak defects and coating omission defects can be suppressed.
[0046]
The suppressing member 34 is formed in the shape of a square plate, and the front end portion is formed in a plane isosceles triangular shape that becomes narrower toward the front end edge, and is inserted between the bar 22 and the film 16. Therefore, when the bubbles in the application liquid 17 in the region D move and come into contact with the leading edge of the suppressing member 34, along with the rotation of the bar 22 and the running of the film 16, along the side surface of the leading end of the suppressing member 34. It can be separated from the area C. Therefore, the occurrence of coating defects on the film 16 can be more reliably suppressed by more reliably suppressing the entrapment of air bubbles in the coating liquid 17 whose coating thickness has been adjusted.
[0047]
When the coating thickness of the coating liquid 17 is adjusted by the bar 22, the coating width of the coating liquid with respect to the film 16 is widened, and each of the suppressing members 34 is inserted into a position corresponding to both ends of the region C. For this reason, it is possible to suppress the occurrence of coating streak defects on the film 16 over the entire coating liquid 17 whose coating thickness has been adjusted.
[0048]
Further, at the boundary between the region C and each region D, a coating streak defect on the film 16 occurs due to the contact of the leading edge of each suppression member 34 with the film 16. For this reason, after manufacturing the film 16 whose surface is coated with the coating film, the film 16 is cut along the coating streak defect formed on the boundary between the region C and each region D, so that the film thickness is constant. In addition, it is possible to easily obtain a film 16 coated with a coating film in which the occurrence of coating defects is suppressed.
[0049]
The distal end of the suppressing member 34 is inserted between the bar 22 and the film 16 such that the distal end edge contacts the bar 22 and the film 16. For this reason, the gap formed between the outer peripheral surface of the bar 22, the lower surface of the film 16, and the distal end surface of the suppressing member 34 is smaller than when the distal end edge is separated from the bar 22 and the film 16. can do. Therefore, by suppressing the entrapment of air bubbles in the coating liquid 17 having the adjusted coating thickness more reliably, the occurrence of coating defects on the film 16 can be suppressed more reliably.
[0050]
-The thickness of the suppressing member 34 is preferably set to 50 to 100 m. In this case, the insertion of the distal end of the suppressing member 34 between the bar 22 and the film 16 can be deepened. For this reason, by suppressing the entrapment of air bubbles in the coating liquid 17 whose coating thickness has been adjusted, the occurrence of coating defects on the film 16 can be suppressed more reliably.
[0051]
A movement adjustment scale 35 is drawn on the downstream side surface of the support rod 31. Therefore, the movement position of the suppressing member 34 can be easily and reliably determined, and each positioning member 33 can be easily and reliably moved to a predetermined position.
[0052]
It should be noted that the embodiment can be modified as follows.
The coating width of the coating liquid 17 on the film 16 is kept constant without spreading as the coating thickness is adjusted by the bar 22. Then, the tip of each restraining member 34 is inserted between the bar 22 and the film 16 at a position corresponding to both ends of the coating solution 17 which is applied to the film 16 and whose coating thickness is adjusted, respectively. You may comprise. In the case of such a configuration, the generation of coating defects on the film 16 can be suppressed by suppressing the entrapment of air bubbles into the coating liquid 17 from both ends of the coating liquid 17 whose coating thickness has been adjusted. .
[0053]
The thickness of the suppressing member 34 may be reduced toward the leading edge. Further, the shape of the suppressing member 34 may be changed to a triangular prism extending in the width direction of the film 16. At this time, the thickness of the suppressing member 34 is reduced toward the leading edge. Further, the shape of the suppression member 34 may be changed to a rod shape extending in the running direction of the film 16.
[0054]
The shape of the tip of the suppression member may be changed to a plane right triangle or the like that becomes narrower toward the tip edge.
The film 16 may be simultaneously subjected to a longitudinal stretching step and a transverse stretching step after the coating step. Further, after forming the film 16 as a biaxially stretched film, a coating step using the coating apparatus 11 and a drying step of the coating liquid 17 may be performed.
[0055]
The bar 22 may be rotated in a direction opposite to the running direction of the film 16 or may not be rotated.
The coating liquid 17 may be configured as a non-Newtonian fluid like the coating liquid 17 for using the film 16 having a coating film coated on the surface as a magnetic tape, or the coating film is coated on the surface. The film 16 may be configured as a Newtonian fluid like a coating solution 17 for use as a photographic photosensitive film.
[0056]
The application liquid 17 may be applied to both sides of the film 16 by applying the application liquid 17 to the center of the lower surface of the film 16 and then applying the application liquid 17 to the center of the upper surface of the film 16.
[0057]
The film 16 may be configured as a single-layer film, or may be configured as a multilayer film such as a co-extruded laminated film. Alternatively, the film 16 may be formed of cellulose or the like, and the stretching step may be omitted and only the coating step may be performed.
[0058]
Next, technical ideas that can be grasped from the embodiment will be described below.
(1) The coating apparatus according to any one of claims 1 to 4, wherein the bubble entrapment suppressing member is inserted so that a leading edge thereof is in contact with a coating thickness adjusting bar and a film. According to this configuration, the occurrence of coating defects on the film can be suppressed more reliably by suppressing the entrapment of air bubbles into the coating liquid whose coating thickness has been adjusted.
[0059]
(2) The coating device according to any one of (1) to (4) and (1), wherein the bubble entrapment suppressing member is formed in a plate shape, and has a thickness of 50 to 100 μm. According to this configuration, the occurrence of coating defects on the film can be suppressed more reliably by suppressing the entrapment of air bubbles into the coating liquid whose coating thickness has been adjusted.
[0060]
【The invention's effect】
The present invention is configured as described above, and has the following effects.
According to the coating apparatus of the present invention, the occurrence of coating defects on the film can be suppressed by suppressing the inclusion of bubbles in the coating liquid whose coating thickness has been adjusted. .
[0061]
According to the coating method of the fifth aspect of the present invention, the coating thickness is reduced by a simple operation of inserting the bubble entrainment suppressing member between the coating thickness adjusting bar and the film from the downstream side of the coating thickness adjusting bar. By suppressing the entrapment of air bubbles in the coating liquid having the adjusted, the occurrence of coating defects on the film can be easily suppressed.
[Brief description of the drawings]
FIG. 1A is a conceptual diagram illustrating a coating apparatus according to an embodiment, and FIG. 1B is a cross-sectional view illustrating a main part of the coating apparatus.
FIG. 2 is a perspective view showing a coating apparatus.
FIG. 3 is a perspective view showing a bubble entrapment suppressing member.
FIG. 4 is a plan view showing a coating thickness adjusting bar.
FIG. 5 is a partially broken side view showing a coating thickness adjusting bar.
FIG. 6 is a sectional view of a main part showing a coating thickness adjusting bar.
[Explanation of symbols]
11: Coating device, 13: Coating mechanism, 14: Coating thickness adjusting mechanism, 16: Film, 17: Coating liquid, 22: Coating thickness adjusting bar, 34: Bubble entrapment member.

Claims (5)

On the surface of the film running continuously, a coating mechanism for applying the coating liquid excessively with respect to the coating amount after the coating thickness has been adjusted, and the coating mechanism provided on the downstream side of the coating mechanism and excessively coated A coating thickness adjusting mechanism for adjusting the coating thickness of the coating liquid, wherein the coating thickness adjusting mechanism adjusts the coating thickness by being pressed against the surface of the film on the side where the coating liquid is excessively applied; Between the coating thickness adjusting bar and the film, a bubble entrainment suppressing member for suppressing entrainment of air bubbles in the coating liquid is provided downstream of the coating thickness adjusting bar. A coating device, wherein the coating device is inserted from the device. A pair of the bubble entrainment suppressing members are inserted into positions corresponding to both end portions of the coating liquid applied to the film and the coating thickness of which is adjusted, thereby suppressing entrainment of air bubbles from both end portions. Item 6. The coating device according to Item 1. 3. The coating apparatus according to claim 1, wherein the bubble entrapment suppressing member is formed to be narrower toward the distal end and the distal end is inserted. 4. The coating liquid is configured such that when the coating thickness is adjusted by the coating thickness adjusting bar, the coating width with respect to the film is widened, and the bubble entrainment suppressing member is provided at both ends of the coating liquid before the coating thickness is adjusted. The coating device according to any one of claims 1 to 3, wherein one pair is inserted into a corresponding position. The coating apparatus according to any one of claims 1 to 4, wherein the coating mechanism applies an excessive amount to the surface of the continuously running film with respect to the coating amount after the coating thickness is adjusted by the coating mechanism. After applying the liquid, the coating thickness of the coating liquid is adjusted by pressing the coating thickness adjusting bar against the surface of the film on which the coating liquid has been excessively applied, and the bubble entrainment suppressing member prevents bubbles from entering the coating liquid. A coating method characterized by suppressing entanglement.

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