JP2012131131A - Sheet lamination method of display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet lamination method that is superior in stable productivity, by switching the peeling/winding between non-defective portions and defective portions of a sheet, without changing a tension applied to the sheet.SOLUTION: A laminated sheet is composed of a base material sheet continuously supplied in a longitudinal direction and a function sheet. The method includes: sending the function sheet on an object where the function sheet is laminated; cutting the function sheet by a length necessary for lamination; peeling the function sheet from the base material sheet by sending the base material sheet with an acute angle; and laminating the peeled function sheet on the object. Also, the rigidity of the function sheet is lowered by incising of the surface of the defective function sheet, thereby switching the peeling or winding operation.

Description

  The present invention relates to a sheet attaching method for attaching a functional sheet having functions such as electromagnetic wave shielding, light transmittance adjustment, and chromaticity adjustment to a display panel such as a plasma display panel or a liquid crystal panel.

  A conventional sheet pasting method as shown in FIG. 13A is known.

  Specifically, it is formed on a conveyance sheet (hereinafter referred to as “base sheet”) for conveying a material wound in a roll shape, and various functions (for example, electromagnetic wave shielding, transmittance adjustment, color tone adjustment). The sheet 111 (hereinafter, referred to as “functional sheet”) to be attached to a product having the function (1) is cut. And it is the technique which peels a functional sheet from a base material sheet in the peeling block 114 front-end | tip, and affixes it on a target object by conveying the base material sheet 113 on the peeling block 114. And although a non-defective part is stuck on a target object among a continuous functional sheet, when there is a defective part, it is necessary to remove. As one of the means, there is known a method in which a defective portion of a functional sheet is attached to a part other than an object (for example, a dummy object) and removed. However, if the object has a large area, it may be large in terms of equipment and cost may increase. Therefore, as shown in FIG. 13B, there is a method in which the defective portion 112 of the functional sheet is not peeled from the base sheet 113 and is wound together with the base sheet 113. Therefore, the technique regarding the switching method in the case where it peels and the case where it does not peel is also known (for example, refer patent documents 1 and 2).

  FIG. 14 is a diagram showing the operation of the peeling / winding switching means disclosed in Patent Document 1.

  14A is a diagram in the case where the functional sheet 111 is peeled from the base sheet 113, and FIG. 14B is a case in which the defective portion 112 of the functional sheet is wound around the base sheet 113 without being peeled off. FIG. In the technique disclosed in Patent Document 1, a defective part of the functional sheet is obtained by changing the angle of the peeling portion by a mechanism that moves back from the state in which the block 115 of the peeling portion protrudes to the fixed roller to the recessed state. A method for preventing 112 from peeling off and winding together with the base sheet 113 is shown.

  FIG. 15 is a diagram showing the operation of the peeling / winding switching means disclosed in Patent Document 2.

  FIG. 15A is a diagram when the functional sheet 111 is peeled off, and FIG. 15B is a diagram when the defective portion 112 of the functional sheet is wound around the base material sheet 113 without being peeled off. The technique disclosed in Patent Document 2 shows a method of preventing the functional sheet from being peeled off by widening the angle of the peeling part by moving the roller 116 in the vicinity of the peeling part, and winding it together with the base sheet. . As described above, Patent Documents 1 and 2 both change the operation of winding the functional sheet on the base material sheet without peeling or peeling by mechanically changing the radius of curvature and the angle at which the sheet is conveyed in the peeling unit. The technique characterized by performing is disclosed.

JP 2005-271437 A JP 2010-058336 A

  However, in the above-described conventional technique, the tension applied to the sheet fluctuates due to a mechanical movement that changes the curvature radius and angle of the leading end of the peeling block, and the lateral deviation of the sheet at the peeling part and the control variation of the sheet feed amount, etc. As a result, the stability of continuous production is affected.

  In addition, in order to wind up the defective part of the functional sheet, a mechanism for detecting the defective part is necessary, and a recognition process for determining the non-defective part / defective part of the sheet (usually sheet surface image inspection by image evaluation, A step of recognizing a mark indicating inspection information formed on a part of the sheet by sheet inspection by the process) is provided in the middle of sheet conveyance. As a result, the tension applied to the sheet fluctuates due to the above-described reason, which may cause erroneous recognition in the recognition process for determining the non-defective part / defective part of the sheet.

  This invention solves the said conventional problem, and aims at providing the sheet | seat bonding method which was stable and excellent in productivity.

  In a laminated sheet consisting of a base sheet and a functional sheet supplied continuously in the longitudinal direction, the functional sheet is fed onto the object to which the functional sheet is to be pasted, and the functional sheet is cut to the length necessary for pasting. Then, by conveying the base sheet at an acute angle, the functional sheet is peeled from the base sheet, and the peeled functional sheet is attached to the object and the object.

  In addition, in the laminating method in which the defective portion of the functional sheet is not peeled off and wound together with the base material sheet, by cutting the surface of the defective functional sheet, the rigidity of the functional sheet is reduced, thereby switching between peeling or winding. Perform the action.

  According to the sheet bonding method of the display panel of the present invention, the displacement of the sheet and the change in tension are less likely to occur, the non-defective part / defective part can be peeled / taken up stably, and the tension applied to the sheet can be reduced. Stable production can be realized by suppressing fluctuations, suppressing occurrence of lateral shift of the sheet at the peeling portion, variation in sheet feed amount, and the like.

Configuration diagram of the sheet used in the present embodiment Schematic configuration diagram of the sticking device used in the present embodiment The figure which shows the winding-up experiment result in Embodiment 1. The figure which shows the content of the winding experiment in Embodiment 1 Cut shape diagram in embodiment 1 Blade shape diagram for forming a cut in the first embodiment Blade shape diagram for forming a cut in the first embodiment Cut shape diagram in embodiment 2 Blade shape diagram for forming a cut in the second embodiment Blade shape diagram for forming a cut in the second embodiment Sheet fracture view Cut shape diagram in Embodiment 3 Operation diagram of peeling / winding switching means Operation diagram of peeling / winding switching means in the preceding example Operation diagram of peeling / winding switching means in the preceding example

(Embodiment 1)
Specifically, first, there is an original fabric on which a laminated sheet composed of a base sheet and a functional sheet is wound, and the laminated sheet drawn from the original is continuously conveyed via a plurality of rollers. Next, the laminated sheet is sent to a cutting process. In this cutting step, the lower base and the blade are held at a predetermined interval, and the laminated sheet is conveyed therebetween.

  And after conveying a lamination | stacking sheet | seat by the length which wants to cut | disconnect a functional sheet, the space | interval of a cutter and a base becomes narrow, and a cutter cuts into a functional sheet, and only a functional sheet is cut | disconnected. Therefore, it is necessary to maintain a gap between the lower base and the blade tip as long as the base sheet is not cut. Hereinafter, a cut state in which only the functional sheet is cut and the base sheet is not cut will be referred to as a half cut.

  Next, the laminated sheet half-cut at a predetermined interval is sent to the peeling step.

  The peeling step usually includes a peeling block having a predetermined angle (usually an acute angle of 90 ° or less) at the tip, and the substrate sheet is applied with a certain tension along the tip. By transporting the laminated sheet so that the material sheet side is in contact, when the half-cut portion reaches the tip of the release block, the base sheet is transported along the release block, and the functional sheet is peeled from the base sheet.

  At this time, since the ease of peeling differs depending on the adhesive strength of the base sheet and the functional sheet and the hardness and rigidity of the functional sheet, the angle of the peeling block tip is preferably 45 ° or less, but the pole tip has no corner. Curved surface processing is applied. The curved surface processing of the pole tip prevents the sheet from being scratched and broken, and has effects such as resistance during sheet conveyance and prevention of static electricity generation.

  Further, in the peeling step, the functional sheet is usually peeled from the base material sheet and attached to the object, but the remaining base material sheet is taken up by a take-up roller. Here, the functional sheet has defective parts such as foreign matter adhesion, dents, scratches, and abnormal thickness of each laminated layer due to manufacturing problems. In the present invention, a method of winding together with the base material sheet without peeling from the material sheet is used.

  In the present invention, the method of switching whether to peel off or wind up the functional sheet at the tip of the peeling block reduces the rigidity of the film by making one or more cuts on the surface of the defective portion of the functional sheet. By preventing the sheet from peeling from the base sheet, switching between the presence and absence of peeling was realized.

  More specific contents will be described below with reference to the drawings.

  First, the structure of the laminated sheet used in this embodiment will be described with reference to FIG.

  The film used in this embodiment was studied using an electromagnetic wave shielding sheet that is directly attached to the display surface of the plasma display panel.

  Details regarding the configuration of the sheet will be described below. Here, FIG. 1A is a configuration diagram in a laminated sheet state, and FIG. 1B shows a configuration diagram in a state of being attached to a plasma display panel.

  First, there is a substrate sheet 1 (30 to 50 μm), on which an adhesive layer 2 (20 to 40 μm), a resin film layer 3 (70 to 130 μm), a metal mesh layer 4 (1 to 10 μm), and a hard coat layer 5 are provided. It is the continuous laminated sheet of the structure laminated | stacked in order of (2-10 micrometers). Here, as the material, the base sheet 1 and the resin film layer 3 can be films of polyethylene terephthalate (PET), polycarbonate (PC), polymethyl methacrylate (PMMA), or the like. The adhesive layer 2 is an adhesive based on an acrylic monomer, and also includes a reaction initiator that initiates polymerization by ultraviolet rays, heat, pressure, or the like. In addition, an adhesive having a function of adjusting light transmittance, color tone, etc. by introducing a dye or the like as required is also possible.

  Next, the metal mesh layer 4 is made of a conductive metal such as copper, silver, gold, aluminum, stainless steel, nickel, cobalt, or an alloy thereof, or a material in which conductive fine particles are dispersed in a binder resin. It is formed on the entire sheet surface. The hard coat layer 5 is formed of a resin having high hardness using an ultraviolet curable resin such as an acrylic resin. However, the sheet material described here is merely an example and is not particularly limited.

  Further, other than the base sheet 1, that is, the adhesive layer 2, the resin film layer 3, the metal mesh layer 4, and the hard coat layer 5 are collectively described as a functional sheet 6 hereinafter. When the functional sheet 6 is bonded to the plasma display panel, the adhesive layer 2 is bonded to the display surface of the plasma display panel 8 and becomes a product as the plasma display 9. Further, the base sheet 1, the adhesive layer 2 and the resin film layer 3 may be collectively referred to as a laminated sheet 7.

  Next, the configuration and operation contents of the entire apparatus will be described with reference to FIG. Specifically, in the sheet bonding apparatus 10, a flow of bonding from a sheet conveyance to a plasma display panel will be described in order.

  First, an original fabric 13 in which a laminated sheet 7 in which a functional sheet 11 and a base sheet 12 are laminated is wound into a roll is installed, and interlocked with a motor (not shown) that can rotate while controlling the sheet feed amount. Yes. The sheet drawn from the original fabric 13 is conveyed through a plurality of conveying rollers 14. Here, the sheet is conveyed to the cutting step 15 with tension applied to the sheet so that the sheet does not sag. In this cutting step 15, for example, the cutting blade 16 and the lower base 18 are held at a predetermined interval, and the laminated sheet is conveyed between them, and the base sheet is placed in contact with the lower base 18.

  Next, the sheet is transported by the length necessary for pasting to the surface of the plasma display panel, which is the object to be pasted, from the previously half-cut position, and the sheet is half-cut by the cutting blade 16. At this time, when the cutting blade 16 or the lower base 18 is driven or the cutting blade 16 and the lower base 18 are driven, the gap between the cutting blade 16 and the lower base 18 is narrowed, and the cutting blade 16 is bitten into the functional sheet 11. Realizes half-cut. The cutting blade 16 may be a half-cut by using a disk-shaped disk blade and running in the width direction of the sheet with the blade edge biting into the sheet.

  Next, the functional sheet half-cut at a predetermined interval is sent to the peeling step 19, and the functional sheet 11 is peeled from the base sheet 12 by being conveyed on the peeling block 20 having a tip angle of about 10 to 45 °. Is done. The peeled functional sheet 11 is sandwiched between the plasma display panel 21 and the bonding roller 22 which are objects to be pasted, and the functional sheet is pasted on the surface of the plasma display panel. The remaining base material sheet 12 is wound around the take-up roller 23 and discarded.

  Here, it is this take-up roller 23 that controls the conveyance of the entire sheet, and a mechanism (not shown) for controlling sheet feeding as required, for example, a base sheet with two rollers Introducing a method in which a sheet is conveyed while being sandwiched with a constant pressure has an effect of realizing a stable conveyance. In addition, the pole tip portion of the peeling block 20 is curved so that there are no corners. It is desirable that the base sheet is treated so as to be slippery from the viewpoint of scratching and breaking the base sheet 12 or reducing resistance during transport and preventing static electricity generation. Moreover, it is also possible to apply a coating that is easy to slip on the surface, if necessary.

  Next, a winding method when a defect exists in the functional sheet 11 will be described.

  In the sheet inspection process 24 that exists in the middle of the sheet conveyance in advance, a mark provided on a sheet surface defect or a position where a defect exists in another process is detected using a detection means 25 such as a recognition camera, and at which position of the sheet Know if there are any defects. Here, the mark used is a mark printed on a line or a dot on the edge of the sheet. However, the mark is not particularly limited as long as it is detected by the detection means.

  After that, in the cutting process, when it is determined that a non-defective part cannot be obtained by calculating from the position of the defect and the length necessary for the plasma display panel that is the object to be pasted, the sheet surface of the unnecessary part (defective part) of the functional sheet 11 Incisions are made at predetermined intervals using a cutting blade 17. Then, the rigidity of the functional sheet is lowered, and the functional sheet is wound together with the base sheet 12 without being peeled off by the peeling block, and is collected by the winding roller 23.

  Here, since the ease of peeling differs depending on the adhesive strength of the functional sheet 11 and the base sheet 12 and the hardness / rigidity of the functional sheet, it is desirable to select the angle of the peeling block 20 that is suitable for the material. Further, since whether or not stable winding is possible depends on the pitch and depth at which the cut is made, further details will be described below.

  As described above, FIG. 3 shows the result of whether winding is possible or not when the pitch and depth of the cutting made by the cutting blade 17 are changed.

  3 is when the functional sheet 11 is conveyed while sliding the base sheet 12 on the peeling block 20 as shown in FIG. At that time, when the pitch of the cuts 26 introduced into the surface of the functional sheet 11 is X, the depth is Y, and X and Y are changed, the functional sheet is not peeled off by the peeling block 20 and is wound together with the base sheet. It is confirmed whether it is taken. Here, the portion where the cut is made this time is as shown in FIG.

  Specifically, FIG. 5A shows a cross section of a sheet cut into the functional sheet 11, and FIG. 5B shows a surface of the functional sheet cut. That is, half-cutting was performed at the end of the non-defective part of the functional sheet 11, and a part having a linearly printed mark (P in the figure) was regarded as a defective part, and was half-cut with an interval of about 150 to 200 mm. Further, the sheet was conveyed in a state where the entire surface in the width direction of the sheet was cut on the surface of the defective portion, and it was confirmed whether the sheet was wound up or peeled off by the peeling block.

  In addition, a metal block having an angle Z of 10 to 30 ° at the tip of the peeling block 20 is used, and the tip of the pole is subjected to curved processing of R2.5 mm on the entire surface in contact with the sheet. Further, as a method of making a cut, a method of making a cut by running the round blade 27 in the sheet width direction as shown in FIG. 6 was used. As shown in FIG. 7, a method of making a cut by pressing the guillotine blade 28 is possible.

The result of the first embodiment will be described with reference to FIGS. The detailed contents of the sheet used in the present embodiment are as follows.
-Base material sheet 1 (35-40 micrometers): Polyethylene terephthalate-Adhesive layer 2 (25-30 micrometers): Acrylic adhesive + pressure-sensitive reaction initiator-Resin film layer 3 (100 micrometers): Polyethylene terephthalate-Metal mesh layer 4 ( 1-3 μm): Copper Hard coat layer 5 (3-5 μm): Acrylic UV curable resin

  As a result of the present embodiment, the tendency of winding to be stabilized was confirmed by narrowing the pitch interval X of the cuts 30 to 30 mm, 20 mm, 15 mm, 10 mm, 5 mm, 3 mm, and 2 mm (FIG. 3 (1)). Specifically, when the pitch interval X was 30 mm and 20 mm, the sheet was completely peeled off at the sheet tip.

  In addition, when the pitch interval X is 15 mm and 10 mm, the sheet center and edges are wound up without being partially peeled at a rate of about once every several times, but it is observed that the sheet falls with its own weight and is unstable. It was a state. In addition, when the pitch interval X was 5 mm, 3 mm, and 2 mm, the winding could be stably performed.

  Next, it was also confirmed that the winding becomes unstable when the cutting depth is reduced to 90%, 70%, and 50% with respect to the functional sheet thickness (FIG. 3 (2)). Specifically, in the case of 90% and 70%, it was possible to stably wind up, but in the case of 50%, a phenomenon that the edge of the sheet was peeled once every several times was confirmed. That is, in the electromagnetic wave shield sheet for plasma display panel used in the present exemplary embodiment, it is desirable to set the pitch of the cuts 27 to be equal to or less than twice the radius of curvature of the peeling block pole tip (corresponding to the diameter).

  Further, the depth of the cut is preferably deeper, but 100% is not necessarily required for the thickness of the functional sheet, and winding is possible if there is a cut of 50% (half) or more. On the other hand, if the cutting depth is set to 100%, there is a possibility that the base sheet is also cut, and a very accurate cutting mechanism is required, and preferably 70% to 90%. A simple cutting mechanism can be used for the device. In other words, it is possible to use not a high-precision apparatus with a high price but an apparatus with a low precision and a low price, and it is considered that there is a merit in terms of cost.

  In addition, by setting the cutting depth to 70% to 90%, the possibility of cutting the base sheet and stopping production can be reduced, and stable production with a wide margin can be realized.

  In the same way, the depth of cut can be set to 70-90%, and it is possible to wind up by making several cuts only at the tip that reaches the peeling block, instead of making cuts on the entire defective part of the functional sheet. It was confirmed. That is, it can be seen that it is important whether the leading edge of the functional sheet is wound around the leading edge of the peeling block by cutting several times. From this, it can be expected that the number of cuts can be reduced only by reducing the number of cuts and shortening the tact time, etc., by limiting the number of cuts to the tip of the defective part of the functional sheet.

  In the present embodiment, an electromagnetic wave shielding sheet for plasma display is used, and a film having a structure in which a metal mesh layer and a hard coat layer are formed on the surface of the resin film layer and an adhesive layer is present on the back side is used. By completely cutting the metal mesh layer and the hard coat layer with higher rigidity than the above, the rigidity of the functional film as a whole is lowered, and even if the cutting depth is 70 to 90%, it can be wound up without peeling. Infer.

(Embodiment 2)
Next, the shape of the cut in the defective portion of the functional sheet in Embodiment 1 can be wound even when a dotted line shape is provided in the width direction of the sheet as shown in FIG. That is, reducing the rigidity of the sheet can also be achieved by cutting the sheet in a part (for example, dotted line shape) instead of the entire region in the width direction of the sheet.

  Moreover, in order to implement | achieve this shape, it can process easily by using the cutter X1 or the guillotine blade X2 which the blade edge | tip protruded intermittently as shown in FIG.9 and FIG.10. Further, when a plurality of cuts are made, it is possible to make a plurality of cuts at a time by shortening the tact time by adopting an apparatus configuration in which a plurality of blades as shown in FIG. 9 or FIG. 10 are arranged in parallel.

  Furthermore, by introducing this shape, the cutting area to be put into the functional sheet is reduced, so that the probability of occurrence of foreign matters due to the cutting is reduced, and the merit of reducing defects due to foreign matters in terms of quality can be expected.

(Embodiment 3)
Next, when the functional sheet 11 is hard to be stretched and is hard and the wound functional sheet is wound up by the peeling block 20, as shown in FIG. Become. Furthermore, in this case, the sheet cannot be wound uniformly and part of the sheet is peeled off or the functional sheet is conveyed in a floating state. There is a problem that the sheet is wrinkled and caught on the roller in the middle of conveyance, causing a bias in the tension on the sheet and a conveyance abnormality due to slipping of the sheet, which may cause continuous production to stop. Will occur.

  Therefore, in the present embodiment, the shape of the cut into the defective sheet portion in the first embodiment is as shown in FIG. That is, as shown in the figure, the sheet can be wound even when the valley portion of the notch 26 is not an acute angle but is flat or curved.

  Further, as a method of forming the cut shape, it is possible to use laser light or the like instead of using a blade. When using laser light, etc., the valley of the cut shape is not an acute angle but can be processed into a curved shape or a pseudo trapezoidal shape, eliminating sheet breakage that occurs from the valley of the cut portion of the functional sheet. Is possible.

  The sheet bonding method of the display panel of the present invention is more effective as the film has higher rigidity, and the surface of the resin layer and the metal layer formed by coating or thin film process is prevented to prevent scratches and dirt. It can be applied to a sheet having a hard coat formed thereon, and can be applied to film bonding in a wide range of fields such as an electromagnetic wave shielding film, a color tone / transmittance adjusting film, and an antireflection film.

DESCRIPTION OF SYMBOLS 11 Functional sheet 12 Base material sheet 13 Raw material 14 Conveyance roller 15 Cutting process 16 Cutting blade 17 Cutting blade 18 Lower stand 19 Peeling process 20 Peeling block 21 Display panel 22 Bonding roller 23 Winding roller 24 Inspection process 25 Detection means 26 Cutting

Claims (8)

In a method in which a laminated sheet formed by laminating a base sheet and a functional sheet is continuously conveyed in the longitudinal direction of the sheet, the base sheet and the functional sheet are separated, and the functional sheet is bonded to an object.
A detection step of detecting defects on the surface of the laminated sheet;
A cutting step of cutting a length necessary for attaching the functional sheet to the object;
When a defect is detected in the laminated sheet in the detection step, a cutting step for cutting into the surface of the defective portion of the functional sheet;
A peeling step for conveying the base sheet to a peeling block having a sharp tip and separating the base sheet and the functional sheet;
A pasting step of pasting the functional sheet peeled in the peeling step to the object,
In the peeling step, the defective portion of the functional sheet is wound up with the base sheet without peeling off,
A sheet bonding method for a display panel, characterized by: The bonding method according to claim 1, wherein the object is a display panel. The bonding method according to claim 2, wherein the object is a plasma display panel. The bonding method according to claim 1, wherein the functional sheet has an electromagnetic wave shielding function. The said functional sheet | seat consists of lamination | stacking of a metal layer, a resin layer, and a hard-coat layer, The bonding method of Claim 4 characterized by the above-mentioned. The laminating method according to any one of claims 1 to 5, wherein incisions to be made in the surface of the defective portion of the functional sheet are continuously made in the width direction of the functional sheet. The cutting method put into the defective part surface of the said functional sheet is the bonding method as described in any one of Claims 1-6 formed with a blade. The cutting method put into the defective part surface of the said functional sheet is the bonding method as described in any one of Claims 1-6 formed with a laser.

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