JP2007050407A - Slide bead coating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a slide bead coating method where a stable bead is formed over the whole in the width direction of a coating liquid, the coating liquid can be applied to the ear part of a web at a uniform thickness without leaving uncoating, and further, even if a web width is changed, the width of the coating liquid can be changed without stopping the driving of a coating line. <P>SOLUTION: A rod 58 is inserted into the liquid film of a coating liquid 14 flowing-down a slide face 40, and the flow of a thick film raised to a horseback shape is formed at the slipstream side of the rod 58. In this way, bead formation in the side edge part of the coating liquid can be stabilized, thus the coating can be performed to the ear part of a web without leaving uncoating. Further, by arranging the rod 58 on the edge line of the web 12, the width regulation of the coating liquid is performed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a slide bead coating method, and in particular in the production of photographic film, photographic printing paper, magnetic recording tape, adhesive tape, pressure-sensitive recording paper, offset printing plate, battery, etc. The present invention relates to a slide bead coating method in which a liquid film-like liquid coating composition (hereinafter referred to as “coating liquid”) that flows down the sliding surface of a coating liquid hopper is applied to a flexible support (hereinafter referred to as “web”).

  One of the methods for applying the coating liquid onto the continuously running web surface is a slide bead coating method. As an apparatus for the slide bead coating method, there is a multilayer slide bead apparatus proposed in US Pat. No. 2,761,791 by Russell et al. This apparatus forms a bead in a gap where a plurality of coating liquids flowing down the slide surface meet a web that is continuously running at the tip of the slide surface, and applies the coating liquid to the web surface via the beads. Is. Therefore, it is important that this type of device can stably form beads.

Further, this type of apparatus must cope with webs having various web widths, and it is necessary to regulate the width of the coating liquid flowing down the slide surface according to the web width. As a method for regulating the width of the coating solution, for example, there is a method using a guide plate disclosed in Japanese Patent Application Laid-Open No. 57-110364. In this method, a pair of guide plates are provided from the base end to the tip end of the slide surface at both side edges in the width direction of the slide surface, and the width of the coating liquid is regulated by this guide.
US Pat. No. 2,761,791

  However, in the conventional slide bead coating apparatus using the guide plate, since the bead formation at both side edges in the coating liquid width direction is not stable, the coating liquid remains uncoated at the web edge portion, so-called “ear part”. There is a drawback that it is easy. Therefore, since the “ear part” must be cut in a subsequent process, a cutting process for cutting the “ear part” must be provided, and the product yield is reduced by the amount that the “ear part” is cut. Problems arise.

  Further, the guide plate has a drawback that the operation of the coating line must be stopped in order to adjust the interval between the guide plates each time the web width changes. Therefore, a time loss due to the operation stop occurs, which causes a problem that the working efficiency is remarkably lowered.

  The present invention has been made in view of such circumstances, and it is possible to form a stable bead over the entire width of the coating liquid, and to apply the coating liquid in a uniform thickness without leaving the “ear part” of the web. Another object of the present invention is to provide a slide bead coating method that can change the coating liquid width without stopping the operation of the coating line even if the web width changes.

  In order to achieve the above object, the present invention provides a liquid film-like liquid coating composition that flows down the sliding surface of the coating liquid hopper between the sliding surface tip and a long flexible support that runs continuously. In the slide bead coating method in which the liquid coating composition is coated on the surface of the flexible support through the bead, a pair of rod-shaped members are formed inside both side edges of the slide surface. The tip of the liquid film is disposed so as to be inserted into the liquid film flowing down the slide surface, and the liquid film on the downstream side of the pair of rod-shaped members is raised to thicken both edges of the liquid film. In addition, the slide bead coating method is characterized in that the thick film is formed at both end positions of the long flexible support that continuously runs or at positions corresponding to inner positions from the both ends. .

  According to the present invention, when the rod-shaped member is inserted and supported in the liquid film of the liquid coating composition flowing down the slide surface, the longitudinal section of the liquid film is formed on a straight line from the rod-shaped member to the slide surface tip (lip tip). A thick film flow bulging in a curved shape can be formed. By forming this thick film flow on the side edge portion of the liquid coating composition, it is possible to stabilize the bead formation at the side edge of the liquid coating composition, so that it does not remain uncoated to the “ear part” of the web. Can be applied.

  Further, by arranging the rod-shaped member so as to substantially coincide with the substantially edge line of the web, the liquid coating composition flowing down the outside of the rod member falls from the tip of the slide surface without being applied to the web surface. The width of the coating composition can be regulated. In this case, when the web width changes, the rod-shaped member inserted in the liquid film only needs to be slid so as to substantially coincide with the edge line of the newly applied web, so the operation of the coating line is stopped. Without limiting the width of the coating liquid.

  As described above, according to the slide bead coating method of the present invention, the rod is inserted into the liquid film of the liquid coating composition flowing down the slide surface, and the both sides of the liquid coating composition are thicker than the central portion. Since the flow of the film is formed, it is possible to apply the film to the ear portion of the long flexible support without being left behind.

  Further, since the width of the liquid coating composition can be regulated simply by inserting a rod into the liquid film, the width of the liquid coating composition can be regulated without stopping the operation of the coating line. Therefore, the slide bead coating method and apparatus according to the present invention does not need to cut the “ear part” in a subsequent process unlike the conventional slide bead coating apparatus using the guide plate. It is not necessary to provide a process, and it is not necessary to cut the “ear part”, so that the product yield can be improved.

  Furthermore, since the slide bead coating method and apparatus of the present invention do not require the operation of the coating liquid line to be stopped for regulating the width of the liquid coating composition unlike the guide plate, the working efficiency can be remarkably improved. .

  Hereinafter, a preferred embodiment of the slide bead coating method according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a side sectional view for explaining a slide bead coating apparatus 10 for carrying out the slide bead coating method of the present invention, and FIG. 2 is a plan view. Further, an example of multilayer slide bead coating in which a plurality of coating liquids are coated on the web surface in the form of a multilayer film will be described below.

  As shown in FIGS. 1 and 2, a plurality of (for example, three types) coating liquids 14 applied to the surface of the web 12 are supplied from a coating liquid tank (not shown) via respective supply lines 16, 18, and 20 to the slide hopper 22. It is supplied to each manifold 24, 26, 28. The slide hopper 22 is mainly composed of a plurality of die blocks 30 and a pair of side plates 32 applied to the side surfaces in a state where the die blocks 30 are combined, and the supply pipes 16, 18, 20 are provided in the slide hopper 22. The flow path of the coating liquid 14 such as the manifolds 24, 26, 28, the slits 34, 36, 38, and the slide surface 40 is formed. Each coating solution 14 supplied to the manifolds 24, 26, 28 is expanded in the coating width direction and then pushed out to the slide surface 40 inclined downward on the upper surface of the slide hopper 22 through the slits 34, 36, 38. Each coating liquid 14 pushed out to the slide surface 40 flows into the multilayer liquid film-like coating liquid 14 without being mixed with each other, flows down the slide surface 40, and reaches the lip tip 42 at the lower end of the slide surface 40. The coating liquid 14 that has reached the lip tip 42 forms a bead 48 in a gap 46 between the lip tip 42 and the web 12 surface that is wound around the backup roller 44 and travels. To be applied.

  A decompression chamber 52 surrounded by the slide hopper 22, the backup roller 44, and the chamber forming member 50 is formed below the backup roller 44. An exhaust pipe 54 connected to a vacuum device (not shown) is connected to the side surface of the chamber forming member 50, and a drain pipe 56 for discharging the coating liquid 14 that has fallen into the decompression chamber 52 is connected to the bottom surface. The decompression chamber 52 functions to stabilize the bead 48 by setting the lower side of the bead 48 to a negative pressure and to make the excess coating liquid 14 not applied to the web 12 easily flow down to the decompression chamber 52.

  A pair of columnar rods 58 are disposed in the direction perpendicular to the slide surface 40 at both side edges of the slide surface 40 in the vicinity of the lip tip 42. The pair of rods 58 are slidable in the width direction of the slide surface 40, and are supported by a slide / advance mechanism (not shown) via the arm 60 so that the tip of the rod 58 can advance and retract with respect to the slide surface 40. Thereby, the pair of rods 58 can be inserted into the liquid film of the coating liquid 14 flowing down the slide surface 40 and can slide in the width direction of the slide surface 40.

  The shape of the rod 58 is not limited to a cylindrical shape, and the cross-sectional shape in the radial direction may be a streamline shape as shown in FIG. 3 or a rectangular shape as shown in FIG. Furthermore, the rod tip may be spherical as shown in FIG. 5, or a taper taper may be formed at the rod 58 tip as shown in FIG. The diameter of the rod 58 is preferably about several mm to several tens of mm. The reason for this is that if the diameter of the rod 58 is too thin, the effect of forming a thick film flow in a straight line from the rod 58 to the lip tip 42 (hereinafter referred to as the rod downstream side) is reduced. On the other hand, if the diameter of the rod 58 is too thick, the coating liquid 14 that has been branched to the left and right by the rod 58 reaches the lip tip 42 before joining on the downstream side.

  The material of the rod 58 is not particularly limited, but is preferably a material that is durable to the coating liquid in consideration of durability. For example, Teflon (registered trademark), plastic or stainless steel, or the surface of the rod 58 material is plated. It may be given. Further, the distance from the lip tip 42 to the center of the rod 58 varies depending on the diameter of the rod 58 and the flow rate of the coating liquid 14, but is preferably about 3 mm to 25 mm when the rod 58 diameter is used. The reason for this is that if the distance is too long, the flow of the coating liquid that has become thick on the downstream side of the rod 58 reaches the lip tip 42 before the upstream side of the rod 58 (opposite the downstream side). This is because the film thickness of the coating liquid 14, that is, the film thickness of the coating liquid flowing through the center portion of the slide surface 40 (the original film thickness applied to the web) is restored. On the other hand, if the distance is too short, as in the case where the diameter of the rod 58 is too thick, the split flow divided into the left and right by the rod 58 reaches the lip tip 42 before joining.

  Next, the operation of the slide bead coating apparatus configured as described above will be described.

  First, as a preparation, the pair of rods 58 are slid in the width direction of the slide surface 40 by operating the slide mechanism of the slide / advance mechanism so that the center of the rod 58 and the edge line 12A of the web 12 coincide (FIG. 2). (See FIG. 4). In this case, although depending on the diameter of the rod 58 and the flow rate of the coating liquid, even if the center of the rod 58 is located with a deviation of ± several millimeters in the width direction of the slide surface with respect to the edge line 12A of the web 12, the “ear portion” of the web 12. There is no problem in applying the coating solution.

  Next, the multilayer coating liquid 14 is caused to flow down on the slide surface 40 of the slide hopper 22 and the slide / advance / retreat mechanism is operated to move the rod 58 into the liquid film of the application liquid 14 flowing down the slide surface 40. Insert so that the tip is immersed. At this time, the rod 58 is inserted until the tip of the rod 58 is immersed in the lowermost layer of the coating liquid 14 having a multilayer shape. In this case, before starting the flow of the coating liquid 14 on the slide surface 40, the tip of the rod 58 may be set in advance so as to be appropriately immersed in the film liquid. The tip of the rod 58 may come into contact with the slide surface 40. However, if the rod 58 is inserted so that it does not come into contact, the flow of the coating solution 14 flows through the gap between the slide surface 40 and the tip of the rod 58. The flow is stabilized without turbulence.

  By the insertion of the rod 58 into the liquid film, the coating liquid 14 flowing down from the upstream side of the rod 58 abuts on the rod 58 and splits to the left and right, and joins again on the downstream side of the rod 58. Then, on the downstream side of the rod 58, on the straight line up to the lip tip 42, as shown in FIG. 8 (viewed from the front of the slide popper), a thick film in which the longitudinal section of the liquid film is raised in a curved shape. Stream 14A is formed. By forming this thick film flow 14 </ b> A at both side edges of the coating liquid 14, it is possible to extremely stabilize the bead formation at the both side edges of the coating liquid 14. As a result, it is possible to apply the “ear part” of the web 12 without being left behind. At this time, the coating liquid 14 that flows away from the outside of the rod 58 by several mm or more flows down to the decompression chamber 52 without being applied to the web 12.

  Therefore, the slide bead coating apparatus 10 of the present invention can reliably apply the coating liquid 14 to the “ear part” of the web 12 with a simple configuration in which the rod 58 is inserted into the liquid film of the coating liquid 14 flowing down the slide surface 40. Can be applied. Further, as an effect of the slide bead coating apparatus 10 of the present invention, the coating liquid 14 is applied to the “ear part” of the web 12, but conversely, the rod 58 is separated by several mm or more inside the web edge 12 </ b> A. Since the liquid coating composition flowing down the outside of the rod 58 is not applied to the web 12, the coating solution 14 can be prevented from being intentionally applied to the “ear part” of the web 12.

  As described above, the slide bead coating apparatus 10 of the present invention regulates the width of the coating liquid 14 by disposing the pair of rods 58 on the edge line 12A of the web 12 in correspondence with the width of the web 12. Can do. In this case, if the width of the web 12 changes, the rod 58 inserted in the liquid film need only be slid so as to be aligned with the edge line 12A of the web 12 to be newly applied. The width of the coating liquid 14 can be regulated without doing so.

  In the case of the slide bead coating apparatus 10 according to the present invention, it is generally preferable to use a pair of rods 58. However, in some cases, the rod 58 is used only on one side of both side edges of the coating solution 14. In addition, a conventional guide plate can be used on the other side. The coating solution 14 used in the present invention includes various types of liquid compositions depending on the application. For example, a photosensitive emulsion layer, an undercoat layer, a protective layer, a back layer, etc. as in a photographic photosensitive material. Coating liquids, coating liquids such as magnetic layers, undercoat layers, lubrication layers, protective layers, back layers, and other coating liquids such as adhesive layers, colored layers, rust prevention layers, etc. These coating liquids contain a water-soluble binder or an organic binder.

  The web 12 used in the present invention includes paper, plastic film, metal, resin-coated paper, synthetic paper and the like. Plastic film materials include, for example, polyolefins such as polyethylene and polypropylene, vinyl polymers such as polyvinyl acetate, polyvinyl chloride and polystyrene, polyamides such as 6,6-nylon and 6-nylon, polyethylene terephthalate, polyethylene-2 6- Polyester such as naphthalate, polycarbonate, cellulose triacetate, cellulose acetate such as cellulose diacetate, etc. are used. The resin used for the resin-coated paper is typically polyolefin such as polyethylene, but is not necessarily limited thereto. An example of the metal web is an aluminum web.

  Next, an embodiment of the slide bead coating apparatus of the present invention will be described. Table 1 shows the composition and viscosity of the coating solution.

As the web, an aluminum web having the dimensions shown in Table 2 was used.

The operating conditions of the slide bead coating apparatus are as shown in Table 3.

  As a result of applying the coating liquid over the entire width direction of the web with the above-mentioned coating liquid composition, web dimensions, and operating conditions, the coating thickness of the coating liquid was uniformly 60 μm to the “ear part” on the web surface. Could be applied. Further, the width of the coating liquid extruded from the slit having a width of 600 mm could be regulated to a width of 500 mm by the rod. That is, the coating solution that flowed down the front flow side of the rod with a width of 600 mm was set to 50 mm on both edges by the pair of rods, and the coating solution on both edges fell to the decompression chamber.

FIG. 1 is a side sectional view for explaining the configuration of a slide bead coating apparatus for carrying out the slide bead coating method of the present invention. FIG. 2 is a plan view illustrating the configuration of the slide bead coating apparatus. FIG. 3 is a plan view when a rod having a streamline cross section is used in the present invention. FIG. 4 is a plan view when a rod having a rectangular cross section is used in the present invention. FIG. 5 is a side sectional view of the present invention when the rod tip is spherical. FIG. 6 is a side sectional view when a taper is formed at the rod tip in the present invention. FIG. 7 is an explanatory diagram showing the flow of the coating liquid by the rod FIG. 8 is an explanatory diagram for explaining the action of the rod.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Slide bead coating device, 12 ... Web, 12A ... Web edge, 14 ... Coating liquid (multilayer film), 22 ... Slide hopper, 24, 26, 28 ... Manifold, 34, 36, 38 ... Slit, 40 ... Slide surface , 42 ... Lip tip, 44 ... Backup roll, 46 ... Gap, 52 ... Decompression chamber, 58 ... Rod, 60 ... Arm

Claims (3)

The liquid film-like liquid coating composition flowing down the sliding surface of the coating liquid hopper forms a bead between the tip of the sliding surface and the long flexible support that continuously runs, and through the bead In the slide bead coating method of coating the liquid coating composition on the flexible support surface,
A pair of rod-shaped members are disposed inside the side edges of the slide surfaces so that the tips thereof are inserted into the liquid film flowing down the slide surfaces, and the liquid on the downstream side of the pair of rod-shaped members The both sides of the liquid film are thickened by raising the film, and the thick film is positioned at both ends of the long flexible support that runs continuously or at a position corresponding to an inner position from both ends. A slide bead coating method characterized by being formed.   The slide bead coating method according to claim 1, wherein the rod-shaped member is slidable in the width direction of the slide surface.   The slide bead coating method according to claim 1 or 2, wherein the rod-shaped member is movable forward and backward in the thickness direction of the thick film portion with respect to the slide surface.

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