JP4360672B2 - Gravure coating equipment - Google Patents

Description

  The present invention relates to a gravure coating apparatus, and more particularly to a technique for stabilizing the coating and improving the life of the coating solution by suppressing evaporation of a solvent contained in the coating solution.

  Conventionally, in gravure coating, as shown in FIG. 4, a doctor blade 3 that supplies a coating liquid to the surface of a gravure roll 2 that is rotationally driven in the coating liquid storage unit 1 and presses it against the surface of the gravure roll 2. After the excess coating liquid on the surface of the gravure roll 2 is scraped off, the coating liquid is transferred to the film base 4 that is sent while contacting the outer peripheral surface of the gravure roll 2. Here, the outer peripheral surface of the gravure roll 2 approaches the inner peripheral surface of the coating liquid reservoir 1 and is spaced at a substantially constant interval, and a uniform amount of coating liquid is supplied to the surface of the gravure roll 2. It is like that. Moreover, although a part of the coating liquid scraped off by the doctor blade 3 is returned to the gap between the doctor blade 3 and the coating liquid storage part 1, most of the coating liquid overflows from the coating liquid storage part 1 and falls. It collects in the bread 5 provided below. Such a configuration is disclosed in, for example, Patent Document 1.

JP 2001-179151 A (summary)

The coating liquid scraped off by the doctor blade and stored in the pan is desirably collected and reused for manufacturing cost reduction. However, when such a coating liquid falls to the pan, it comes into contact with air, and the organic solvent evaporates. At the time of the evaporation, condensation and moisture absorption occur, and moisture is taken into the coating liquid. As a result, the coating liquid contains moisture or reacts with moisture to increase the viscosity, resulting in a problem that the coating properties deteriorate or the physical properties of the coating film after drying deteriorate. The current situation is disposal.
Therefore, the present invention can minimize the contact of the coating liquid overflowing from the coating liquid reservoir with the air, thereby suppressing the deterioration of the coating liquid and enabling reuse. An object of the present invention is to provide a gravure coating apparatus capable of stabilizing coating with a reused coating solution.

The gravure coating apparatus of the present invention accommodates a roll that is rotated around an axis and brought into contact with a sheet-like substrate, and a lower half portion of the roll, and a coating liquid is provided between the inner surface of the roll and the outer peripheral surface of the roll. In a gravure coating apparatus comprising a coating liquid storage unit to be supplied and a blade whose tip edge is brought into contact with the outer peripheral surface of the roll and scrapes off excess coating liquid, the coating liquid storage unit is provided along the axial direction of the roll. A first recess into which the coating liquid that has been extended and scraped off by the blade flows, a second recess into which the remaining coating liquid after being applied to the sheet-like substrate flows, and into the first and second recesses. Rutotomoni provided a flow path for discharging the coating liquid to the outside of the coating liquid reservoir portion, at both ends of the coating liquid reservoir portion, preventing the leaching of the axially outer coating liquid in contact with the outer peripheral surface of the roll The inner packing The packing, a notch for circulating the axially outward coating liquid in communication with the recess provided, is characterized by supplying the discharged coating liquid again to the coating liquid reservoir portion.

  When the coating liquid is applied to the film base by the gravure coating apparatus as described above, the coating liquid is supplied from the coating liquid supply means having a pump or the like to the coating liquid reservoir. The supplied coating liquid passes through the interior of the coating liquid reservoir and is supplied to the gap with the roll, and is carried on the surface of the rotating roll. In this case, the liquid level of the coating liquid is set as high as possible in order to shorten the contact time with the air until it is applied to the film base. For this reason, the coating liquid scraped off by the blade overflows without returning to the gap between the roll and the coating liquid reservoir. The overflowing coating liquid flows into the first recess extending along the axial direction of the roll, and is discharged to the outside from the flow path provided in the coating liquid storage section. Moreover, the remaining coating liquid after apply | coating to a sheet-like base material flows into a 2nd recessed part, and is discharged | emitted outside from the flow path provided in the coating liquid storage part. Therefore, the coating solution scraped off by the blade and the remaining coating solution after coating do not overflow, and the time for contact with air is short, so that there is little deterioration due to evaporation of volatile components in the coating solution and it is discharged. The applied coating solution can be supplied again to the coating solution storage unit and used.

  Here, inner packings that contact the outer peripheral surface of the roll and prevent leaching of the coating liquid to the outside in the axial direction are provided at both ends of the coating liquid storage part, and the coating liquid is communicated with the recesses in the inner packing. It is preferable to provide a notch that circulates outward in the axial direction. According to such an aspect, the coating liquid can be prevented from leaking outside through the roll, and the coating liquid that has flowed into the recess can be efficiently collected by collecting on both sides of the coating liquid storage section. it can. Thereby, contact with the air of a coating liquid can be decreased further.

  Furthermore, an outer packing that comes into contact with the outer peripheral surface of the roll is provided on the outer side in the axial direction of the inner packing, and a coating liquid inflow portion is provided between the outer packing and the inner packing to allow the coating liquid flowing into the recess to flow. It is preferable that the coating liquid is discharged from the liquid inflow part to the outside of the coating liquid storage part. According to such an aspect, the leakage of the coating liquid flowing into the coating liquid inflow portion is prevented by the outer packing. A hole can be provided in the coating liquid inflow portion, and the coating liquid can be returned to the coating liquid supply means by a pipe connected to the hole.

  It is more preferable to provide a cover that covers the upper surface of the roll and the coating liquid inflow portion above the coating liquid inflow portion. According to such an aspect, since the penetration | invasion of the air to a coating liquid inflow part is suppressed, degradation of a coating liquid can be prevented effectively.

  In the gravure coating apparatus according to the present invention, the coating liquid reservoir is coated on the sheet-like base material and the first concave portion into which the coating liquid extending along the axial direction of the roll and scraped off by the blade flows. Since the second concave portion into which the remaining residual coating liquid flows and the flow path for discharging the coating liquid flowing into the first and second concave portions to the outside of the coating liquid storage portion are provided, the coating liquid storage portion It is possible to minimize the contact of the overflowing coating liquid and excess coating liquid after coating with the air, thereby reducing the deterioration of the coating liquid and allowing it to be reused. The effect that the application | coating with the applied coating liquid can be stabilized is acquired.

Hereinafter, preferred embodiments of the present invention will be described with reference to FIGS.
FIG. 1 is a side view showing the entire gravure coating apparatus according to the embodiment. In the figure, reference numeral 10 denotes a guide roll. The film base B unwound from a reel (not shown) around which the film base B is wound is guided by the guide roll 10 and sent to the drying part by the guide roll 13 through the idle rolls 11 and 12.

  A manifold (coating liquid storage unit) 20 is disposed in the middle of the idle rolls 11 and 12. In the figure, reference numeral 21 denotes a manifold body. A supply pipe (not shown) through which the coating liquid supplied from a coating liquid supply means (not shown) flows into the manifold body 21 and the manifold body 21 are discharged from the manifold body 21. A discharge pipe (not shown) for returning the coating liquid to the coating liquid supply means is connected.

  A groove 24 having a semicircular cross section is formed on the upper surface of the manifold body 21. A coating liquid discharge port 25 extending in the longitudinal direction is formed in the groove 24 (see FIG. 2), and the coating liquid discharge port 25 is connected to the supply pipe via a flow path 26 formed in the manifold body 21. Has been.

  A gravure roll (roll) 27 that is rotated counterclockwise in FIG. 1 is disposed in the groove 24. The film base B is pressed against the gravure roll 27 by the idle rolls 11 and 12. The width and diameter of the gravure roll are not particularly limited, but those having a width of 300 mm or more, particularly about 300 to 2000 mm are preferred, and those having a diameter of 20 mm or more, particularly about 20 to 200 mm are suitably used.

  On the upper surface of the manifold main body 21, flanges (second recesses, first recesses) 30 and 31 are formed. It is desirable that the eaves 30 and 31 have a slight downward slope from the center of the manifold body 21 toward both ends. Inner packings 32 are attached to both ends of the manifold body 21. The inner packing 32 has a shape substantially matching the contour formed by the groove 24 and the flanges 30 and 31 formed in the manifold body 21. The inner packing 32 contacts the outer periphery of the gravure roll 27 and prevents the coating liquid from leaking out. Further, the inner packing 32 is formed with a notch 32a that is continuous with the flanges 30 and 31, and the coating liquid that has flowed into the flanges 30 and 31 is allowed to flow out.

  Outer packings 33 spaced from the inner packing 32 are attached to both ends of the manifold main body 21, and a coating liquid inflow portion 34 is formed between the inner packing 32. The outer packing 33 prevents the coating liquid flowing into the coating liquid inflow portion 34 from leaking through the gravure roll 27 by contacting the outer periphery of the gravure roll 27. The discharge pipe is connected to the coating liquid inflow portion 34. Therefore, the coating liquid that has flowed into the coating liquid inflow portion 34 is discharged through the discharge pipe and returned from the discharge pipe to the coating liquid supply means.

  As shown in FIG. 3, covers 36 are attached to both ends of the manifold body 21. The cover 36 covers the upper half of the gravure roll 27 and also covers the outer part from the upper part of the cutout 32a of the inner packing. Thereby, the inflow of air to the coating liquid inflow portion 34 is suppressed.

  In FIG. 1, reference numeral 40 denotes a blade stand, and a doctor blade (blade) 41 is attached to the blade stand 40. The leading edge of the doctor blade 41 is pressed against the outer peripheral surface of the gravure roll 27 with a predetermined contact pressure.

  Next, the operation of the gravure coating apparatus having the above configuration will be described. The coating liquid supplied from the coating liquid supply means is discharged from a coating liquid discharge port 25 formed in the groove 24 of the manifold body 21 through the flow path 26. The discharged coating liquid is stored in a gap between the groove 24 and the gravure roll 27. The gravure roll 27 rotates counterclockwise in FIG. 1, and the coating liquid adheres to the surface of the gravure roll 27 and is carried. At that time, the supply amount of the coating liquid is adjusted so that the liquid level of the coating liquid is kept constant.

  The excess coating liquid adhering to the surface of the gravure roll 27 is scraped off by the doctor blade 41 and falls along the outer peripheral surface of the gravure roll 27. A part of the dropped coating liquid is returned between the gravure roll 27 or the gravure roll 27 and the ridge 31, but most of it overflows and falls to the ridge 31. Then, the coating liquid dropped on the flange 31 flows to both ends of the manifold main body 21 and flows into the coating liquid inflow portion 34 through the notch 32 a of the inner packing 32. Thus, since the coating liquid that has flowed into the gutter 31 can be collected in the coating liquid inflow portion 34 and efficiently discharged, the contact of the coating liquid with air can be reduced. Further, in the above embodiment, since the cover 36 that covers the upper half of the gravure roll 27 and the upper surface of the coating liquid inflow portion 34 is provided, the intrusion of air into the coating liquid inflow portion 34 is suppressed, and the coating liquid is deteriorated. Can be effectively prevented. The other ridge 30 plays a role of collecting the remaining liquid adhering to the gravure roll 27 after the coating liquid is transferred to the film base B. Further, it has a function of causing the coating liquid to flow in when the coating liquid overflows due to a trouble in the coating liquid supply means.

  Next, the coating liquid flows out from the coating liquid inflow portion 34 to the discharge pipe and is returned to the coating liquid supply means. Thus, since the time for the coating liquid scraped off by the doctor blade 41 to come into contact with air is short, there is little deterioration due to evaporation of volatile components in the coating liquid. Therefore, as described above, the coating liquid discharged to the discharge pipe can be supplied again to the manifold 20 for use.

  The coating liquid remaining on the surface of the gravure roll 27 without being scraped off by the doctor blade 41 comes into contact with the film base B running in the direction opposite to the rotation direction of the gravure roll 27, and from the surface of the gravure roll 27 to the film base B Is transferred to the surface. The film base B to which the coating liquid has been transferred is sent to the drying part by the guide roll 13 and dried.

  As described above, in the gravure coating apparatus, since the time for the coating liquid scraped off by the doctor blade 27 to contact the air before reaching the discharge pipe is short, there is little deterioration due to evaporation of the volatile components of the coating liquid, The discharged coating solution can be supplied again to the manifold 20 and used, and the coating with the reused coating solution can be stabilized.

In addition, this invention is not limited to the said embodiment, A various change is possible as follows.
(1) The coating liquid that has flowed down to the troughs 30 and 31 can be collected at the center of the troughs 30 and 31 and discharged therefrom.
(2) By providing a filter in the discharge pipe, the coating liquid to be reused can be cleaned.
(3) Since the tops of the eaves 30 and 31 are open, there is a concern about contact with the air of the coating solution. Therefore, a flow path communicating with the coating liquid inflow portion 34 can be formed inside the manifold main body 21, and the branch flow path branched from this flow path can be connected to the eaves 30 and 31.

It is a side view which shows the gravure coating apparatus of embodiment of this invention. It is a perspective view which shows the gravure coating apparatus of embodiment of this invention. It is a perspective view which shows the gravure coating apparatus of embodiment of this invention. It is a side view which shows an example of the conventional gravure coating apparatus.

Explanation of symbols

20 Manifold (coating solution reservoir)
27 Gravure roll (roll)
30 樋 (second recess)
31 樋 (first recess)
32 Inner packing 33 Outer packing 36 Cover 41 Doctor blade (blade)

Claims (3)

A roll rotated around an axis and brought into contact with the sheet-like substrate; a lower half portion of the roll; a coating liquid storage section for supplying the coating liquid between the inner surface of the roll and the outer peripheral surface of the roll; In the gravure coating apparatus comprising a blade whose tip edge is brought into contact with the outer peripheral surface of the roll and scrapes off the excess coating liquid,
The coating liquid reservoir extends along the axial direction of the roll, the first recess into which the coating liquid scraped off by the blade flows, and the remaining coating liquid after being applied to the sheet-like substrate. a second recess for the inflow, these first, the coating liquid flows into the second concave portion is provided a flow path for discharging to the outside of the coating solution reservoir Rutotomoni,
Inner packings that contact the outer peripheral surface of the roll and prevent leaching of the coating liquid to the outside in the axial direction are provided at both ends of the coating liquid storage part, and the coating liquid is communicated with the recesses in the inner packing. A gravure coating apparatus, characterized in that a notch that circulates outward in the axial direction is provided, and the discharged coating liquid is supplied again to the coating liquid reservoir . An outer packing that contacts the outer peripheral surface of the roll is provided on the outer side in the axial direction of the inner packing, and a coating liquid inflow portion is provided between the outer packing and the inner packing to allow the coating liquid that has flowed into the recess to flow in. 2. The gravure coating apparatus according to claim 1 , wherein the coating liquid is discharged from the coating liquid inflow part to the outside of the coating liquid storage part. The gravure coating apparatus according to claim 2 , wherein a cover that covers an upper surface of the roll and the coating liquid inflow portion is provided above the coating liquid inflow portion.

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