JP2011158908A - Method for producing liquid crystal display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a liquid crystal display element, in which such a problem can be solved simultaneously that an optical film is cut without causing the external appearance defect thereof and is prevented from being torn when stuck continuously to a liquid crystal panel. <P>SOLUTION: The method for producing the liquid crystal display element includes steps of: cutting a long sheet-like material F1, which is obtained by layering an adhesive layer F14 and a carrier film F12 temporarily stuck to the adhesive layer F14 on the optical film F11 including a polarizer, at predetermined intervals while keeping the continuity of the carrier film F12; conveying the obtained optical film fragment; exfoliating the carrier film F12 through tensile force from the optical film fragment to expose the adhesive layer; and continuously sticking the optical film fragment to the liquid crystal panel while effectively using the exposed adhesive layer. When the long sheet-like material is cut, the depth of cut reaches the carrier film F12 substantially and is less than a half of the thickness of the carrier film F12 at least at both ends of the carrier film F12 in the width direction. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention provides a long sheet-like material in which an adhesive layer and a carrier film temporarily attached to the adhesive layer are laminated on an optical film containing a polarizer, while maintaining the continuity of the carrier film. It is related with the manufacturing method of the liquid crystal display element which peels a carrier film from the obtained optical film piece, and sticks it on a liquid crystal panel continuously after cut | disconnecting to predetermined spacing.

  In a liquid crystal display device, a polarizing plate is indispensable, but the transfer and pasting of the polarizing plate are often performed in a sheet form in which each is completely cut. However, since there are problems such as low productivity and misalignment at the time of bonding due to curling of the polarizing plate, a method of continuously bonding has been proposed (see, for example, Patent Documents 1 and 2).

  In this continuous laminating method, the polarizing plate is unwound from a roll in a raw state and transferred, and by half-cutting to leave a part (carrier film) in the thickness direction of the laminated structure including the polarizing plate, After the individual polarizing plates are formed, bonding is performed. That is, since the continuity is maintained in the portion not cut by the half cut, it can be used as a carrier, and after the cut polarizing plate is conveyed by tension, it is continuously pasted on the liquid crystal panel. .

  However, in such a half cut, the pressure-sensitive adhesive layer may remain without being completely cut depending on the accuracy of the depth of cut. When such an adhesive layer is left uncut, the remaining uncut portion of the adhesive layer is torn off when the optical film is peeled off from the carrier film. Cause permanent deformation. In particular, when a pressure-sensitive adhesive having a low elastic modulus is used, such a pressure-sensitive adhesive layer is likely to be deformed. And in the process from a half cut to affixing, since a polarizing plate is on the carrier film, end face processing cannot be performed. As a result, bubbles are generated due to the deformation of the adhesive layer in the liquid crystal panel (ie, the liquid crystal display element) to which the polarizing plate is bonded, or peeling from the end portion occurs. Further, light escapes from such a portion. There is also a risk of causing fatal defects.

  Therefore, in order to avoid such a problem, it is conceivable to completely cut the pressure-sensitive adhesive layer so that the cut depth in such a half cut reaches the layer of the carrier film. When the pressure-sensitive adhesive layer is completely cut, the pressure-sensitive adhesive can be prevented from being deformed when the optical film piece is peeled from the carrier film (see Patent Document 1).

JP 2005-037416 A JP-A-57-52017

However, depending on the cut depth of the half cut, the carrier film may be broken even if the conveyance distance is short due to the tension applied during conveyance or peeling of the carrier film. In particular, in a system in which a film is continuously bonded to a liquid crystal panel while applying tension, the carrier film is transported in an inching state that repeats the start and stop of transport unlike a monotonous transport system. The stress applied to the film reaches several times the normal time, and a large load is generated when the carrier film is peeled off using an edge-shaped member or the like, so that the risk of film breakage increases dramatically.

  According to the experiments conducted by the present inventors, it has been found that the risk of film breakage is significant when the edge is cut deeper than the central portion in the width direction of the film. That is, it has been found that when the end portion of the film is deeply cut, the mechanical strength of the entire film is remarkably lowered in such an inching state, and it is easy to cause breakage during conveyance.

  In this regard, Patent Document 1 proposes that the bottom dead center of the cutter in the half cut is set to 0 to 0.5 times the thickness of the release film to eliminate the remaining adhesive layer. (See claim 5, paragraph 0021). However, in patent document 1, the problem in the continuous bonding mentioned above is not fully considered. For this reason, even if the bottom dead center of the cutter is set, it is difficult to avoid the occurrence of a deeply cut portion due to variations in the accuracy of the cut depth, and the risk of film breakage in the inching state cannot be avoided. There is a case.

  Therefore, an object of the present invention is to provide a method for manufacturing a liquid crystal display element that can simultaneously solve the problem of cutting an optical film that does not cause poor appearance and preventing film breakage in continuous bonding.

The above object can be achieved by the present invention as follows.
That is, in the method for producing a liquid crystal display element of the present invention, a long sheet-like product in which an adhesive layer and a carrier film temporarily attached to the adhesive layer are laminated on an optical film including a polarizer is used. A liquid crystal display that cuts at predetermined intervals while maintaining the continuity of the film, conveys the obtained optical film piece, and continuously bonds the liquid crystal panel to the liquid crystal panel with the exposed adhesive layer peeled off by tension. In the element manufacturing method, the cutting is performed while moving the cutting means in the width direction of the carrier film at a cutting depth substantially reaching the carrier film, and the cutting is at least both ends in the width direction of the carrier film. Thus, the depth of cut is less than half the thickness of the carrier film. Here, the “cutting depth at which the cutting substantially reaches the carrier film” means a state in which the cutting reaches the carrier film at a length of 80% or more of the cutting distance in the width direction of the carrier film. This can be done by setting the depth of cut reaching the film layer as the target value for half-cutting. For example, even when the target value of the cutting depth of the half cut is outside this range, the case where the cutting reaches the carrier film with the above length due to the accuracy of the cutting device is included.

  According to the method for manufacturing a liquid crystal display element of the present invention, the cutting is substantially the cutting depth reaching the carrier film, and the cutting depth is less than half the thickness of the film at at least both ends in the width direction of the carrier film. It is possible to simultaneously solve the problem of cutting an optical film that does not cause an appearance defect and preventing breakage of the film in continuous bonding. In other words, when half-cutting an optical film / adhesive layer / carrier film laminated in this order so as to be approximately the same size as a liquid crystal panel to be attached, leaving the carrier film, The depth is not constant depending on the blade accuracy and machine accuracy (mounting accuracy), and there is an influence of an error in the film thickness, so that a cut portion and a continuous portion of the adhesive layer are likely to occur. Thereby, the appearance defect which does not disappear with time, such as the pressure-sensitive adhesive sticking out at the time of bonding, or bubbles are generated.

  On the other hand, in order to avoid this problem, when a notch that cuts more than half of the thickness of the carrier film is added, depending on the notch state (depth) at both ends of the film, the transport distance is short due to the tension applied in the carrier. Even at a distance, the carrier film may break. On the other hand, in the present invention, by setting the average depth and the setting of the depth of cut at both ends by variation control within a predetermined range, it is continuous with cutting of the optical film that does not cause an appearance defect. The problem of preventing breakage of the film in bonding can be solved at the same time.

  In the above, when peeling the said carrier film, it is preferable to reverse the conveyance direction of a carrier film to an acute angle, for example using an edge-shaped member, and to peel from the said adhesive layer. In the present invention, since the depth of cut is less than half the thickness of the carrier film at at least both ends in the width direction of the carrier film, the carrier film is difficult to break even with such a heavy peeling method. The carrier film can be smoothly and sequentially peeled from the pressure-sensitive adhesive layer.

  Further, when performing the cutting, the carrier film supported on the pedestal by a cutting blade is cut, and the surface height of the pedestal is made lower at both ends in the width direction of the carrier film than other parts. Preferably it is. Although cutting using a cutting blade can make it difficult to generate dust or the like, there is a problem that it is difficult to slightly change the cutting depth (for example, on the order of μm). On the other hand, by decreasing the surface height of the pedestal at least at both ends in the width direction of the carrier film, the distance between the pedestal surface and the cutting blade can be partially increased, and the carrier film at that portion The depth of cut can be reduced more reliably.

  Further, when the depth of cut into the carrier film in cutting is c and the thickness of the carrier film is d, 60% or more of the cutting distance preferably satisfies 3 μm <c <(d / 2) μm. By making such a cut depth distribution, the cut depth reaches the carrier film more reliably, and at least at both ends in the width direction of the carrier film, the cut depth is more surely less than half the thickness of the film. It can be.

  Moreover, it is preferable that the thickness of the said carrier film is 20 micrometers or more and less than 40 micrometers. With such a thickness, the pressure-sensitive adhesive layer can be more securely cut to prevent poor appearance while maintaining a cut depth of less than half of the film thickness at at least both ends in the width direction of the carrier film. it can.

  The carrier film preferably has a breaking strength of 180 MPa or more. When the breaking strength is within this range, by making the cutting depth less than half of the film thickness at at least both ends in the width direction of the carrier film, it is possible to more surely prevent the film from breaking during continuous bonding. Become.

  In the cutting, it is preferable that the portion where the pressure-sensitive adhesive layer is not completely cut is 10% or less of the cutting distance, and the thickness of the pressure-sensitive adhesive layer where the portion is not cut is 3 μm at the maximum. When the ratio and thickness of the pressure-sensitive adhesive layer that is not completely cut are within this range, bubbles due to deformation of the pressure-sensitive adhesive layer are unlikely to occur in the bonded liquid crystal panel (liquid crystal display element), and peeling from the edge portion is also caused. Hard to occur. In addition, fatal defects such as light leakage due to these are less likely to occur.

The flowchart which shows an example of the manufacturing method of the liquid crystal display element of this invention. Schematic configuration diagram showing an example of a manufacturing system used in the method for manufacturing a liquid crystal display element of the present invention Schematic configuration diagram showing an example of a manufacturing system used in the method for manufacturing a liquid crystal display element of the present invention The figure for demonstrating an example of the laminated structure of a 1st, 2nd optical film The schematic block diagram which shows an example of the cutting device used for the manufacturing method of the liquid crystal display element of this invention

  The method for producing a liquid crystal display element according to the present invention includes a long sheet-like material in which an adhesive layer and a carrier film temporarily attached to the adhesive layer are laminated on an optical film including a polarizer. The film is cut at a predetermined interval while maintaining continuity, and the obtained optical film pieces are transported, and the carrier film is peeled off by tension, and is continuously bonded to the liquid crystal panel with an adhesive layer exposed.

  The manufacturing method of the liquid crystal display element of this invention can be implemented by the process as shown, for example in FIG. That is, the method for producing a liquid crystal display element of the present invention includes, as main processes, a cutting process of a long sheet-like material, and a bonding process of continuously bonding the cut optical film pieces to the liquid crystal panel, Furthermore, you may provide the roll original fabric preparation process, a conveyance process, and an inspection process. Hereafter, each process is demonstrated based on FIG.

  (1) 1st roll original fabric preparation process (FIG. 1, S1). The wound body of the present invention is prepared as a first roll raw fabric. The width | variety of a 1st roll original fabric is dependent on the bonding size of a liquid crystal panel. The long sheet-like material wound as the first roll raw fabric is obtained by laminating an adhesive layer and a carrier film temporarily attached to the adhesive layer on an optical film including a polarizer.

  As shown in FIG. 4, for example, the laminated structure of the first sheet-like material F1 includes a first optical film F11, a first carrier film F12, and a surface protective film F13. The first optical film F11 includes a first polarizer F11a, a first film F11b having an adhesive layer (not shown) on one side thereof, and a second film having an adhesive layer (not shown) on the other side. F11c. In the case of the apparatus shown in FIGS. 2 to 3, the carrier film H <b> 11 is first used as the first carrier film F <b> 12, and after peeling it, the carrier film H <b> 12 is used.

  The first and second films F11b and F11c are, for example, polarizer protective films (for example, triacetyl cellulose film, PET film, etc.). The second film F11c is bonded to the liquid crystal panel surface side via the first adhesive F14. A surface treatment can be applied to the first film F11b. Examples of the surface treatment include a hard coat treatment, an antireflection treatment, a treatment for the purpose of prevention of sticking, diffusion or antiglare, and the like. The first carrier film F12 is provided via the second film F11c and the first adhesive layer F14. Moreover, the surface protection film F13 is provided through the 1st film F11b and the adhesive layer F15. Hereinafter, a laminated structure of a polarizer and a polarizer protective film may be referred to as a polarizing plate.

  (2) Transport process (FIG. 1, S2). The first sheet material is fed out from the first roll prepared and installed, and conveyed downstream. The first transport device that transports the first sheet-like material includes, for example, a nip roller pair, a tension roller, a rotation drive device, an accumulation device, a sensor device, a control device, and the like. The first sheet-like material has a first carrier film, which functions as a carrier film.

  (3) First inspection step (FIG. 1, S3). A defect of the first sheet is inspected using a first defect inspection apparatus. The defect inspection method here includes a method of photographing and processing images with transmitted light and reflected light on both sides of the first sheet material, and an inspection optical film between the CCD camera and the inspection object. A method of taking an image and processing an image by arranging it so as to be in crossed Nicols with the polarization axis of the target polarizing plate (sometimes referred to as 0 degree cross), and an inspection optical film between the CCD camera and the inspection object In addition, it is arranged (sometimes referred to as x degree cross) so as to be at a predetermined angle (for example, a range of greater than 0 degree and within 10 degrees) with the polarization axis of the polarizing plate to be inspected, and image photographing / image processing is performed. A method is mentioned. Note that a known method can be applied to the image processing algorithm, and for example, a defect can be detected by density determination by binarization processing.

  In the image capturing / image processing method using transmitted light, foreign matter inside the first sheet can be detected. In the image capturing / image processing method using reflected light, the adhered foreign matter on the surface of the first sheet-like object can be detected. In the image photographing / image processing method using the 0-degree cross, mainly surface foreign matter, dirt, internal foreign matter, etc. can be detected as bright spots. In the image photographing / image processing method using the x-degree cross, a nick can be mainly detected.

  The defect information obtained by the first defect inspection apparatus is linked with the position information (for example, position coordinates), transmitted to the control apparatus, and can contribute to the cutting method by the first cutting apparatus described later. . In the first inspection step, from the viewpoint of improving the accuracy of the inspection, it is preferable that the carrier film is peeled off after the inspection after the carrier film is peeled off before the inspection as in the manufacturing system shown in FIG. This is the same in the second inspection process. In the case of this inspection method, the carrier films before and after the inspection may be the same or different.

  Moreover, the same yield improvement effect can be acquired by performing an inspection process at the time of manufacture of a roll original fabric instead of performing such an inspection process by a continuous manufacturing process. That is, based on the result of the inspection performed previously, the defect information of the first and second sheet-like products in a predetermined pitch unit (for example, 1000 mm) is provided at one end in the width direction of the first and second rolls. This is a case in which (defect coordinates, defect type, size, etc.) are attached as code information (for example, QR code, barcode). In such a case, the code information is read and analyzed at a stage prior to cutting, and cut into a predetermined size in the first and second cutting steps (sometimes referred to as skip cut) so as to avoid the defective portion. Then, the part including the defect is removed or bonded to a member that is not a liquid crystal panel, and a non-defective sheet-shaped product cut to a predetermined size is bonded to the liquid crystal panel. As a result, the yield of the liquid crystal panel is greatly improved.

  (4) 1st cutting process (FIG. 1, S4). The first cutting device cuts the first optical film and the first pressure-sensitive adhesive layer into a predetermined size (half cut) without cutting the first carrier film. Based on the defect information obtained by the first defect inspection apparatus 14, the cutting is performed so as to avoid the defect. Thereby, the product yield with respect to the 1st sheet-like object F1 improves significantly. The first optical film piece including the defect is excluded by a first rejection device 19 to be described later, and is not attached to the liquid crystal panel W. The cutting process will be described in detail later.

  (5) 1st optical film bonding process (FIG. 1, S5). While removing the first carrier film using the first peeling device, the first optical film from which the first carrier film has been removed is stuck to the liquid crystal panel via the first pressure-sensitive adhesive layer using the first bonding device. Match. At the time of bonding, the first optical film and the liquid crystal panel are sandwiched by a pair of rolls and pressure bonded. When peeling a carrier film, it can peel from an adhesive layer by reversing the conveyance direction of a carrier film to an acute angle using an edge-shaped member.

  (6) Cleaning step (FIG. 1, S6). If necessary, the surface of the liquid crystal panel is cleaned by a polishing cleaning device and a water cleaning device. The cleaned panel is transported to the inspection apparatus by the transport mechanism.

  (7) 2nd roll original fabric preparation process (FIG. 1, S11). The wound body of this invention is prepared as a 2nd roll original fabric. The laminated structure of the second sheet-like material has the same configuration as that of the first sheet-like material, but is not limited to this. As shown in FIG. 4, the laminated structure of the second sheet-like material F2 has the same configuration as the first sheet-like material, but is not limited to this. For example, the second sheet-like material F2 includes a second optical film F21, a second carrier film F22, and a surface protection film F23. The second optical film F21 includes a second polarizer 21a, a third film F21b having an adhesive layer (not shown) on one side thereof, and a fourth film having an adhesive layer (not shown) on the other side. F21c.

  The third and fourth films F21b and F21c are, for example, polarizer protective films (for example, triacetylcellulose film, PET film, etc.). The fourth film F21c is bonded to the liquid crystal panel surface side via the second pressure-sensitive adhesive layer F24. The third film F21b can be subjected to a surface treatment. Examples of the surface treatment include a hard coat treatment, an antireflection treatment, a treatment for the purpose of prevention of sticking, diffusion or antiglare, and the like. The second carrier film F22 is provided via the fourth film F21c and the second pressure-sensitive adhesive layer F24. Moreover, the surface protection film F23 is provided through the 3rd film F21b and the adhesive layer F25.

  (8) Transporting process (FIG. 1, S12). The second sheet material is fed out from the prepared second roll raw material and is conveyed downstream. The second conveyance device that conveys the second sheet-like material is configured by, for example, a nip roller pair, a tension roller, a rotation drive device, an accumulation device, a sensor device, a control device, and the like.

  (9) Second inspection step (FIG. 1, S13). A defect of the second sheet is inspected using a second defect inspection device. The defect inspection method here is the same as the method using the first defect inspection apparatus described above.

  (10) Second cutting step (FIG. 1, S14). The second cutting device cuts (half cuts) the second optical film and the second pressure-sensitive adhesive layer into a predetermined size without cutting the second carrier film. If necessary, it is configured to cut so as to avoid the defect based on the defect information obtained by the second defect inspection apparatus. Thereby, the yield of a 2nd sheet-like thing improves significantly. The second sheet-like material including the defect is excluded by the second exclusion device and is not attached to the liquid crystal panel.

  (11) 2nd optical film bonding process (FIG. 1, S15). Next, after the second cutting step, the second optical film from which the second carrier film has been removed using the second laminating device is removed while the second carrier film is removed using the second peeling device. The adhesive layer is bonded to a surface different from the surface to which the first optical film of the liquid crystal panel is bonded. In addition, before bonding a 2nd optical film to a liquid crystal panel, a liquid crystal panel may be rotated 90 degree | times with the conveyance direction switching mechanism of a conveyance mechanism, and a 1st optical film and a 2nd optical film may be made into a cross Nicol relationship. . At the time of bonding, the second optical film and the liquid crystal panel are sandwiched between rolls and pressure bonded.

  (12) Liquid crystal panel inspection process (FIG. 1, S16). The inspection device inspects a liquid crystal panel having optical films attached to both sides. Examples of the inspection method include a method of taking an image and processing an image using reflected light on both sides of the liquid crystal panel. As another method, a method of installing an inspection optical film between a CCD camera and an inspection object is also exemplified. Note that a known method can be applied to the image processing algorithm, and for example, a defect can be detected by density determination by binarization processing.

  (13) A non-defective product of the liquid crystal panel is determined based on the defect information obtained by the inspection apparatus. The liquid crystal panel determined to be non-defective is conveyed to the next mounting process. If a defective product is determined, a rework process is performed, a new optical film is applied, and then inspected.If a good product is determined, the process proceeds to a mounting process. Discarded.

  In the above series of manufacturing steps, the liquid crystal display element can be preferably manufactured by executing the first optical film bonding step and the second optical film bonding step on a continuous production line.

  Next, a manufacturing system for performing each process will be described. As shown in FIGS. 2 to 3, the manufacturing system includes a first transport device 12, a first pre-inspection peeling device 13, a first defect inspection device 14, a first carrier film laminating device 15, and a first cutting device. 16, what is provided with the 1st peeling apparatus 17 and the 1st bonding apparatus 18 is illustrated. In the present invention, the first optical film can be inspected with high precision by including the first pre-inspection peeling device 13, the first defect inspection device 14, and the first carrier film laminating device 15, but these devices are omitted. It is also possible to do.

  The first roll raw material of the long first sheet-like material F1 is installed on a roller mount device that is linked to a motor or the like so as to rotate freely or at a constant rotational speed. The rotational speed is set by the control device, and the drive is controlled.

  The first transport device 12 is a transport mechanism that transports the first sheet-like material F1 to the downstream side. The first transport device 12 includes a nip roller pair, a tension roller, a rotation drive device, an accumulation device A, a sensor device, a control device, and the like, and is controlled by the control device. The first transport device 12 transports the optical film before cutting or the optical film piece after cutting to the first bonding device 18 while applying tension to the first carrier film. In addition, in the position of the 1st defect inspection apparatus 14, only an optical film is conveyed downstream without using a 1st carrier film.

  The first pre-inspection peeling device 13 has a configuration in which the carrier film H11 is peeled off from the first sheet-like material F1 that has been conveyed and wound around a roll 132. The winding speed around the roll 132 is controlled by a control device. The peeling mechanism 131 has a knife edge portion with a sharp tip, and the carrier film H11 is wound around the knife edge portion and reversely transferred to peel the carrier film H11 and the carrier film H11. The first sheet-like material F1 is transported in the transport direction.

  The first defect inspection apparatus 14 performs defect inspection after the carrier film H11 is peeled off. The first defect inspection device 14 detects the defect by analyzing the image data captured by the CCD camera, and further calculates its position coordinates. The position coordinates of this defect are provided for the skip cut by the first cutting device 16 described later.

  The 1st carrier film bonding apparatus 15 bonds the carrier film H12 to the 1st optical film F11 via the 1st adhesive layer F14 after a 1st fault test | inspection. As shown in FIG. 2, the carrier film H12 is unwound from the roll 151 of the carrier film H12, and the carrier film H12 and the first optical film F11 are sandwiched by one or a plurality of roller pairs 152. Apply the pressure of and stick together. The rotation speed, pressure control, and conveyance control of the roller pair 152 are controlled by a control device.

  The first cutting device 16 cuts the first optical film F11 at a predetermined interval after the carrier film H12 is bonded and in a state where the continuity of the carrier film H12 is maintained. The present invention is characterized in that the cut depth substantially reaches the carrier film H12 at that time, and the cut depth is less than half of the thickness of the carrier film H12 at at least both ends in the width direction of the carrier film H12. To do. In the case of the first sheet-like material F1 shown in FIG. 4, the first optical film F11, the surface protective film F13, the first pressure-sensitive adhesive layer F14, and the pressure-sensitive adhesive layer F15 are of a predetermined size without completely cutting the carrier film H12. Disconnected.

  Examples of the cutting means used in the first cutting apparatus 16 include cutting apparatuses equipped with various cutting blades, laser apparatuses, and other known cutting means. Especially, it is preferable to use the cutting device provided with the knife-type cutting blade which does not accompany cutting (saw type) from a viewpoint that it is hard to take out dust, such as cutting waste. Cutting devices equipped with a knife-type cutting blade include those equipped with rotary round blades, fixed round blades, cutter knives, etc., for cutting while moving the cutting blade in the cutting direction. As what cuts without moving to a direction, what is equipped with a pressing blade blade and a straight Thomson blade is mentioned.

  In the present invention, as a result, the cut depth may be set constant over the entire width of the carrier film as long as the cut depth is less than half the thickness of the carrier film at at least both ends in the width direction of the carrier film. It is preferable to make the depth of cut shallower at both ends in the width direction of the carrier film than at other portions. In the latter case, there are a method for adjusting the surface height of the pedestal, a method for adjusting the height of the cutting blade, and a method for adjusting both. From the viewpoint of improving accuracy, a method for adjusting the surface height of the pedestal is more preferable. preferable. As a method of adjusting the height of the cutting blade, when the cutting blade is a slide type, a method of preparing a rail on which the cutting blade moves may be used. In the case of using a laser device, a method of adjusting the cutting depth by controlling the laser output is preferable.

  As such a cutting device, as shown in FIG. 5, the carrier film F12 supported on the pedestal 161 by the cutting blade 162 is cut and compared with other portions at both ends in the width direction of the carrier film F12. It is preferable to use an apparatus in which the surface height of the pedestal 161 is lowered. In this example, the height of the surface 161a of the pedestal 161 is set lower than the center portion by the height H in the range of the length L from both ends of the carrier film F12.

  When such a pedestal 161 is used, when the cutting is performed by sliding the tip 162a of the cutting blade 162 parallel to the surface of the pedestal 161 at the same height, the pedestal 161 is formed at both ends in the width direction of the carrier film F12. The distance between the surface and the cutting blade can be partially increased, and the cutting depth of the carrier film F12 at that portion can be made shallower than the central portion.

  In FIG. 5, the cutting blade 162 for the cutter knife is shown, but the same effect as described above can be obtained even if the type of the cutting blade 162 is changed. For example, it is not limited to a moving cutting device such as a rotary round blade or a fixed round blade, and the same applies to a cutting device that raises and lowers a Thomson blade (push-cut type).

  When a laser device is used as the cutting device, a holding table for sucking and holding the first sheet-like material F1 from the back surface is arranged, and the laser device is arranged above the first sheet-like material F1. It moves horizontally so as to scan the laser in the width direction of the first sheet F1, and the remaining portion is cut at a predetermined pitch in the transport direction, leaving the lowermost carrier film H12. In addition, an air nozzle that blows warm air toward the cutting portion so as to be sandwiched from the width direction of the first sheet F1, and a smoke collection device that collects gas (smoke) generated from the cutting portion conveyed by the hot air It is preferable that the duct and the duct are integrally configured.

  10-50 mm is preferable and, as for the length L in the base 161, 15-40 mm is more preferable. Further, the height H at both ends of the carrier film F12 is preferably from 3 μm to 30% of the thickness of the carrier film F12, more preferably from 2 μm to 25% of the thickness of the carrier film F12.

  In the example shown in FIG. 5, the step height is provided and the surface height is lowered by a surface parallel to the central portion of the pedestal 161. For example, the step height is formed as a curved surface or the height is gradually changed. (Tapered) may be used.

  The depth of cut in cutting is preferably such that 60% or more of the cutting distance satisfies 3 μm <c <d / 2 μm, where c is the depth of cut into the carrier film and d is the thickness of the carrier film. It is more preferable that more than 10% satisfy this condition, and more than 80% more preferably satisfy this condition.

  Considering such conditions, the thickness of the carrier film is preferably 20 μm or more and less than 40 μm. In addition, even in the same incision state, from the viewpoint of more reliably preventing breakage of the carrier film in continuous bonding, the break strength of the carrier film is preferably 180 MPa or more, and the break strength is more than 200 MPa. preferable.

  Due to the cutting as described above, almost no part of the pressure-sensitive adhesive layer is completely cut off, and it is difficult for bubbles to be generated due to deformation of the pressure-sensitive adhesive layer in the bonded liquid crystal panel (liquid crystal display element). The peeling is less likely to occur, and the fatal defects such as light leakage due to these are less likely to occur. Specifically, it is preferable that the part where the pressure-sensitive adhesive layer is not completely cut is 10% or less of the cutting distance and the thickness of the part where the pressure-sensitive adhesive layer is not cut is 3 μm at the maximum.

  Based on the position coordinates of the defect detected in the first defect inspection process, the first cutting device 16 cuts to a predetermined size so as to avoid the defect portion. That is, the cut product including the defective portion is rejected as a defective product by the first rejecting device 19 in a subsequent process. Alternatively, the first cutting device 16 may continuously cut into a predetermined size while ignoring the existence of the defect. In this case, it can be configured such that the portion is removed without being bonded in the bonding process described later. The control in this case also depends on the function of the control device.

  Moreover, the 1st cutting device 16 is provided with the holding table which adsorbs and hold | maintains the 1st sheet-like object F1 from the back surface as needed. When the first sheet-like material F1 is sucked by the holding table, the accumulation device A of the transport mechanism moves in the vertical direction so as not to stop the continuous transport of the first sheet-like material F1 on the downstream side and the upstream side. Is configured to do. This operation is also controlled by the control device.

  The 1st bonding apparatus 18 is 1st sheet-like material F1 (1st optical film piece) by which the carrier film H12 was peeled by the 1st peeling apparatus 17 after the said cutting process via the 1st adhesive layer F14. Affix to the liquid crystal panel W. The transport path of the first sheet-like material F1 is above the transport path of the liquid crystal panel W.

  As shown in FIG. 3, when bonding, the first optical film F <b> 11 is bonded to the liquid crystal panel W surface by the pressing roller 181 and the guide roller 182 while being pressed. The pressing pressure and driving operation of the pressing roller 181 and the guide roller 182 are controlled by a control device.

  The peeling mechanism 171 of the first peeling device 17 has an edge-shaped member with a sharp tip, and the carrier film H12 is wound around the knife edge portion and reversely transferred to peel off the carrier film H12 and the carrier. The first sheet-like material F1 (first optical film F11) after peeling the film H12 is configured to be sent out to the liquid crystal panel W surface. The peeled release mold H12 is wound around a roll 172. The winding control of the roll 172 is controlled by the control device.

  From the viewpoint of smoothly peeling the carrier film H12 from the pressure-sensitive adhesive layer, the radius of curvature at the tip of the edge-shaped member is, for example, 1 to 2 mm, and preferably 1 to 1.5 mm. Moreover, the tension | tensile_strength (tensile | tensile_strength for peeling) which arises in the carrier film H12 after peeling is 0.1-0.2N / mm from a viewpoint of the stable conveyance, for example, and 0.15-0.2N / mm is 0.15-0.2N / mm. preferable.

  As a bonding mechanism, it is comprised from the pressing roller 181 provided in the bonding position P31, and the guide roller 182 arrange | positioned facing it. The guide roller 182 is composed of a rubber roller that is rotationally driven by a motor, and is arranged so as to be movable up and down. In addition, a pressing roller 181 made of a metal roller that is rotationally driven by a motor is disposed directly above it. When the liquid crystal panel W is sent to the bonding position, the pressing roller 181 is raised to a position higher than the upper surface so as to open a gap between the rollers. Note that both the guide roller 182 and the pressing roller 181 may be rubber rollers or metal rollers. As described above, the liquid crystal panel W is cleaned by various cleaning devices and is transported by the transport mechanism R. The transport control of the transport mechanism R is also controlled by the control device.

  The 1st rejection apparatus 19 which excludes the 1st sheet-like material F1 containing a fault is demonstrated. When the first sheet F1 including the defect is conveyed to the bonding position, the guide roller 182 moves vertically downward. Next, the roller 192 around which the adhesive tape 191 is stretched moves to a fixed position of the guide roller 182. By moving the pressing roller 181 vertically downward, the first sheet-like material F1 including the defect is pressed against the adhesive tape 191, and the first sheet-like material F1 is attached to the adhesive tape 191. One sheet F1 is wound around a roller 193.

  The liquid crystal panel W1 manufactured as described above is transported to the downstream side, and the second optical film F21 (second sheet-like material F2) is bonded thereto. Since the series of steps is the same as the first optical film F11 (first sheet-like material F1), description thereof is omitted.

  Formation of a liquid crystal display device using the liquid crystal display element of the present invention can be performed according to conventional methods. That is, a liquid crystal display device is generally formed by appropriately assembling components such as a liquid crystal cell (liquid crystal panel), an optical film, and an illumination system as necessary, and incorporating a drive circuit. As the liquid crystal cell, for example, an arbitrary type such as a TN type, STN type, π type, VA type, or IPS type can be used.

  An appropriate liquid crystal display device such as a liquid crystal display device in which an adhesive optical film is disposed on one side or both sides of a liquid crystal cell, or a backlight or a reflector used in an illumination system can be formed. In that case, the optical film according to the present invention can be installed on one side or both sides of the liquid crystal cell. When optical films are provided on both sides, they may be the same or different.

  Further, when forming a liquid crystal display device, for example, a single layer or a suitable part such as a diffusing plate, an antiglare layer, an antireflection film, a protective plate, a prism array, a lens array sheet, a light diffusing plate, a backlight, etc. Two or more layers can be arranged.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. Evaluation items in Examples and the like were measured as follows.

(1) Average cutting depth For the cutting distance of 400 mm after half-cutting, the cutting depth was measured at 40 points at intervals of 10 mm, and the average value was obtained. With reference to the interface between the separator and the pressure-sensitive adhesive layer, “+” indicates a state where the separator is deeply cut, and “−” indicates a state where the cut does not reach the separator.

(2) Poor appearance appearance Evaluation was made such that no bubble or peeling occurred at the end of the half-cut portion at the time of pasting, ○ if these disappeared over time, and × if they did not disappear.

(3) Cutting ratio The ratio of the length of the cut portion where the cutting depth c is in the range of 3 μm <c <d / 2 μm corresponding to the layer thickness d of the carrier film is measured when determining the average cutting depth. It was obtained from 40 points.

(4) Uncut remaining ratio The ratio of the distance at which the adhesive remains uncut with respect to the cut distance was determined from 40 points measured when determining the average depth of cut.

(5) Uncut height From the 40 points measured when determining the average depth of cut, the height of the uncut portion of the highest portion where the adhesive remains uncut was measured.

(6) Both-ends part full cut length The length by which the film was cut | disconnected completely in the both-ends part (left-right both sides) of a carrier film was measured.

(7) Uncut thickness at both end portions The thickness (μm) at which both end portions of the carrier film have continuity, that is, the uncut thickness was measured. The value obtained by subtracting this value from the thickness of the film is the cutting depth.

(8) Breakage evaluation in carrier It was evaluated whether or not a breakage occurred in the carrier film after the optical film was cut and before the carrier film was peeled off.

(9) Evaluation of breakage during peeling When peeling the carrier film, the presence or absence of breakage when peeling using a knife-edge peel bar was evaluated.

Example 1
As the sheet-like material, an optical film as a polarizing plate, a carrier film (PET, thickness 38 μm, breaking strength 202 MPa), and a surface protective film (PET, thickness 38 μm) are respectively pressure-sensitive adhesive layers (acrylic pressure-sensitive adhesive, thickness 23 μm). ) Was used. The optical film consists of a polarizer (iodine-oriented PVA film, thickness 28 μm) and a polarizer protective film (triacetylcellulose film, thickness 80 μm) laminated on both sides via an adhesive layer (PVA adhesive, thickness 80 nm). ).

A cutting apparatus having a long body (width 400 mm) of this sheet-like material having a flat surface and a cutting mechanism for sliding the cutting edge of the cutting blade for a cutter knife at a constant height (moving speed 350 mm / second). Thus, the average depth of cut was changed in the range of −15 μm to +35 μm, and cut at predetermined intervals. Table 1 shows the results of the above evaluation on the cut part.

  From the results of Table 1, it can be seen that no breakage is observed when the cutting ratio is 60% or more. In addition, when the uncut ratio is 10% or less and the uncut height is 3 μm or less, the evaluation of the pasting appearance defect is “good”.

Example 2
In Example 1, cutting and evaluation were performed under the same conditions as in Example 1 except that the thickness of the carrier film was changed to 25 μm and the average depth of cut was changed in the range of −12 μm to +20 μm. . The results are shown in Table 2.

  From the results in Table 2, it can be seen that no breakage is observed when the cutting ratio is 60% or more. In addition, when the uncut ratio is 10% or less and the uncut height is 3 μm or less, the evaluation of the pasting appearance defect is “good”.

Example 3
Using the optical film piece after being cut in Example 1 and Example 2, the bonding apparatus shown in FIG. 3 continued to the apparatus of FIG. 2 (the radius of curvature of the edge of the peeling bar used for peeling the carrier film) The liquid crystal panel and the optical film piece were bonded to each other at 1.5 mm, an inversion angle of 170 ° (inner angle of 10 °), and a tension of 0.15 N / mm). Table 3 shows the results of the above evaluation.

  From the results in Table 3, it was found that the durability was remarkably lowered when both end portions of the carrier film were in a full cut state. Further, it has been found that at both end portions, when the depth of cut is more than half of the thickness of the carrier film, breakage occurs during peeling of the carrier film.

F1 1st sheet-like material F2 2nd sheet-like material F11 1st optical film F11a 1st polarizer F11b 1st film F11c 2nd film F12 1st carrier film F13 Surface protection film F14 1st adhesive layer F21 2nd optical film F21a second polarizer F21b third film F21c fourth film F22 second carrier film F23 surface protective film F24 second adhesive layer 12 first transport device 13 first pre-inspection peeling device 14 first defect inspection device 15 first carrier Film bonding device 16 First cutting device 17 First peeling device 18 First bonding device 19 First exclusion device 161 Base 162 Cutting blade (cutting means)
R Transport mechanism W LCD panel

Claims (7)

A long sheet-like material in which a pressure-sensitive adhesive layer and a carrier film temporarily attached to the pressure-sensitive adhesive layer are laminated on an optical film containing a polarizer is cut at predetermined intervals while maintaining the continuity of the carrier film. In the method for producing a liquid crystal display element, the obtained optical film piece is transported and the carrier film is peeled off by tension and is continuously bonded to the liquid crystal panel with the exposed adhesive layer.
Manufacturing of a liquid crystal display element characterized in that the cutting has a cutting depth substantially reaching the carrier film and a cutting depth less than half of the thickness of the carrier film at at least both ends in the width direction of the carrier film. Method.   The method for producing a liquid crystal display element according to claim 1, wherein when the carrier film is peeled off, the carrier film is peeled from the pressure-sensitive adhesive layer by using an edge member to reverse the carrier film transport direction to an acute angle.   When performing the cutting, the carrier film supported on the pedestal by a cutting blade is cut, and the surface height of the pedestal is made lower at both ends in the width direction of the carrier film compared to other parts. A method for producing a liquid crystal display element according to claim 1 or 2.   The cutting depth to the carrier film in cutting is c, and the thickness of the carrier film is d, 60% or more of the cutting distance satisfies 3 μm <c <(d / 2) μm. A method for producing a liquid crystal display element according to claim 1.   The method for producing a liquid crystal display element according to claim 1, wherein the carrier film has a thickness of 20 μm or more and less than 40 μm.   The method for manufacturing a liquid crystal display element according to claim 1, wherein the carrier film has a breaking strength of 180 MPa or more.   In the said cutting | disconnection, the part in which the adhesive layer is not cut | disconnected completely is 10% or less of a cutting distance, and the thickness of the adhesive layer of the part which is not cut | disconnected is 3 micrometers at maximum. Liquid crystal display element manufacturing method.

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