JPH10328595A - Thin film coating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable uniformly recovering resin liquid in the width direction as it is in a straight flow state by arranging a recovery auxiliary utensil having a slope for guiding resin liquid below a cleaning doctor and adjacent to it and making the lower end part of the slope face into resin liquid of a resin dam. SOLUTION: On the tip side of a resin clam 5, that is, between a metal roll 2 and a doctor roll 3, a resin liquid recovery auxiliary utensil 15 having the shape of an triangle in section is arranged below a cleaning doctor 6 and adjacent to it. Resin liquid in the dam 5 passes the underside of the bottom surface of the utensil 15 and fed onto a web 1. The resin liquid prevented from forming a coating film by the doctor roll 3 is reversed and moved to between the doctor roll 3 and the auxiliary utensil 15, stuck on the doctor roll 3, and is scraped off by the cleaning doctor 6. The resin liquid scraped off crosses the top of the auxiliary utensil 15 and is moved in a layer to a slope on the rear side and flows down on the slope. Since the lower end part of the slope is dipped into the resin liquid in the dam 5, the resin liquid is recovered in the resin dam, left in a straighten flow state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method in which a metal roll and a doctor roll are arranged so as to rotate in opposite directions to each other, and a resin dam is provided in the vicinity of a gap between the two. A resin film is applied to the outside of the web while forming a film thickness with a doctor roll, and the resin liquid remaining on the doctor roll is removed by a cleaning doctor arranged above the resin dam and collected into the resin dam. The present invention relates to a coating apparatus which is used to apply a resin liquid, particularly a high-viscosity resin liquid, to a thin film.

[0002]

2. Description of the Related Art As a coating apparatus of this kind,
The one shown in FIG. 1 is used. A resin film 5 is formed on the web 1 while passing through the resin dam 5 on the web 1 running on the rotating metal roll 2 and determining the film thickness by the doctor roll 3 rotating in the opposite direction to the metal roll 2. It is supposed to. This device has a wide range of adjustment of the film thickness, and it is difficult to form longitudinal streaks (vertical streaks) on the film surface due to the action of the shearing force of the roll. It is preferably used. However, since excess resin adhering to the surface of the doctor roll 3 is to be removed from the surface of the roll 3 by the cleaning doctor 6 disposed above the resin dam 5, the removed resin becomes irregular. While being collected, it falls along the roll 3 or falls vertically from the contact point at the edge of the cleaning doctor 6 into the resin dam 5 and is collected. At this time, the collected resin entrains air and generates a turbulent flow in the resin liquid in the resin dam 5, so that the coating film 4 is formed with the resin mixed with air bubbles, or the resin liquid is mixed in the width direction. There was a problem that the pressure was not uniform and the film thickness could not be stabilized. Further, since the resin dam 5 is in an open state, the viscosity of the resin liquid changes due to the evaporation of the solvent, and dust in the air is mixed when the resin liquid is collected, which causes inconvenience in forming a mirror surface. I was

[0003]

Technical Problem The present invention arranges a metal roll and a doctor roll so as to rotate in opposite directions to each other, provides a resin dam close to a gap between the two, and runs on the metal roll through the resin dam. Applying a resin film while forming a film thickness by a doctor roll on the outside of the web to be
Resin liquid remaining on the doctor roll is removed by a cleaning doctor placed above the resin dam and collected in the resin dam. In a coating device, the resin liquid is uniformly collected in the width direction while still flowing. A first problem is to make it possible, and a second problem is to prevent air or dust from being involved when uniformly collecting the resin liquid.

[0004]

[Technical Means] The technical means for achieving the first technical problem is as follows: (a) A recovery auxiliary tool having an inclined surface for guiding a resin liquid is disposed below and adjacent to a cleaning doctor. (B) The lower end of the inclined surface faces the resin liquid of the resin dam (see claim 1). The technical means for achieving the second technical problem is, in addition to the above technical means, (c) shutting off the resin dam from the outside air (see claim 3).

[0005] Since the resin liquid recovery aid is disposed below and adjacent to the cleaning doctor, the resin scraped off by the cleaning doctor moves to the recovery aid as it is. Since this auxiliary tool has an inclined surface for guiding the resin liquid, the resin liquid flows down in a layer along the inclined surface and does not collect irregularly. Since the lower end of this inclined surface is exposed to the resin liquid of the resin dam, the resin liquid flowing down is collected in the dam in a layered static flow state, and the amount of liquid collected in the width direction is made uniform. Can be.

When the cross-sectional shape of the recovered liquid guide is substantially triangular, the distance between the bottom surface and the web and the distance between the other slope and the cleaning doctor can be stabilized (see claim 2). As a result, the amount of resin supplied between the rolls is constant and a stable coating film can be formed on the web, and the amount of resin to be recovered is also constant and the amount of resin flowing down the inclined surface is uniform. Can be changed. The cross-sectional shape of the guide does not need to be strictly triangular. It is possible to adopt an arc shape so that the bottom surface is parallel to the web and the other slope is parallel to the peripheral surface of the cleaning doctor, and the triangular top is formed round and the laminar flow is smoothly inclined. You may make it transfer to. The angle of the resin recovery slope is designed according to the type and viscosity of the resin liquid forming the coating film.

In addition to the above technical configuration, if the resin dam is sealed off from the outside air, the amount of recovery in the width direction can be evenly prevented, and external dust and dust can be prevented from being mixed into the lower resin liquid. (See claim 3). In this case, in addition to the cleaning roll, it is desirable that a liquid level sensor and other utensils generally used in the coating apparatus be disposed in the closed chamber.

[0008]

According to the present invention, the resin liquid scraped off by the cleaning doctor can be uniformly collected in the width direction and guided as it is in the resin dam. As a result, the resin pressure in the width direction becomes substantially constant and the coating film can be stabilized. There are advantages. Further, since the layered resin is directly collected in the dam, the collected resin does not involve air, and there is no possibility of generating turbulence in the resin liquid in the dam (see claims 1 and 2). In addition, as a result that we can prevent dust and garbage invasion by sealing resin dam,
There is an advantage that the mirror surface of the coating film can be reliably maintained (see claim 3).

[0009]

FIG. 1 is a schematic side view of a coating apparatus according to the present invention. The resin dam 5 disposed between the metal roll 2 and the doctor roll 3 is installed in a state in which the resin dam 5 is shielded from the outside air by the partition wall 11, thereby preventing intrusion of dust in the air and preventing evaporation of the resin liquid. . A window 12 made of a transparent glass or resin plate is attached to the rear of the partition 11 so that the state inside the dam 5 can be seen. The resin dam 5 has a step portion 7 formed on the rear side so that the resin liquid supplied from the resin liquid supply port 10 temporarily stays at the rear portion of the step portion 7 and is installed in the dam 5. When the resin liquid is supplied in accordance with the detection signal of the liquid level sensor 13, the resin liquid is supplied to the dam 5 in a layered manner over the step portion so that the internal pressure of the resin liquid in the dam 5 becomes uniform. I have.

The metal roll 2 through which the web 1 passes
The gap between the doctor roll 3 and the doctor roll 3 can be finely adjusted by combining a taper cotter, a ball screw, a worm wheel, and the like (not shown) so as to cope with a change in web thickness and a change in film thickness.

The tip side of the resin dam 5, that is, the metal roll 2
A resin liquid collecting aid 15 having a triangular cross section is disposed below and in close proximity to the cleaning doctor 6 between the cleaning roller 6 and the doctor roll 3. This auxiliary tool has a surface facing the doctor roll 3 formed in an arc shape corresponding to the roll. The auxiliary tool 15 is attached to the left and right partition walls of the resin dam 5 (not shown) so that the position can be adjusted in the up-down direction and the front-back direction. The resin liquid in the dam 5 is supplied onto the web 1 through the lower side of the bottom surface of the auxiliary tool 15, and the resin liquid, which has been prevented from forming a coating film by the doctor roll 3, adheres to the doctor roll 3 as it is. 15 and is scraped off by the cleaning doctor 6. The scraped resin liquid passes over the top of the assisting tool 15 as it is and moves in a layered manner to the rear slope, and flows down the slope. Since the lower end of the slope faces the resin liquid in the dam 5, the resin liquid is collected in the resin dam 5 with a still flow.

[Brief description of the drawings]

FIG. 1 is a schematic side view of a conventional coating apparatus.

FIG. 2 is a schematic side view of a coating apparatus according to the present invention.

[Explanation of symbols]

1 web, 2 metal roll, 3 doctor roll,
4 coatings, 5 resin dam, 6 cleaning doctor, 1
0 resin liquid supply port, 11 partition, 13 liquid level sensor,
15 Resin liquid recovery aid

Claims (3)

[Claims] 1. A metal roll and a doctor roll are arranged so as to rotate in opposite directions to each other, a resin dam is provided close to a gap between the two, and a web outside the web running on the metal roll passing through the resin dam. A resin film is applied while forming a film thickness by a doctor roll, and the resin liquid remaining on the doctor roll is removed by a cleaning doctor arranged above the resin dam and collected in the resin dam. A coating apparatus in which a recovery assisting tool having an inclined surface for guiding a resin liquid is disposed adjacent to and below a cleaning doctor, and a lower end portion of the inclined surface faces the resin liquid of the resin dam. 2. The coating apparatus according to claim 1, wherein a cross section of the recovered liquid guide is substantially triangular. 3. The coating apparatus according to claim 1, wherein the resin dam is shielded from outside air.