JP2008020598A - Method for manufacturing laminate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for continuously manufacturing a laminate by layering conveyance bodies at different layering angles while change of properties of a layer and breakage of the layer during transfer are suppressed by controlling transferability of the layer when the laminate is formed. <P>SOLUTION: In the method for manufacturing the laminate having a first intermittently conveying step for conveying a first conveyance body along a first conveyance axis, a second intermittently conveying step for conveying a second conveyance body along a second conveyance axis at an angle different from that of the first conveyance axis synchronizing with the first intermittently conveying step so that the second conveyance body can overlaps with the first conveyance body and a layering step for layering a portion or all of a first to second overlapping part where the first and the second conveyance bodies overlap with each other, the second conveyance body is formed by layering at least two layers of first and second layers having 0.03 to 0.30 N/25 mm interlayer peeling strength and the layered product comprising the first conveyance body and the first layer is manufactured by peeling the first and the second layers from each other after the first conveyance body and the first layer are layered in the first to second overlapping part. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a laminate, and more particularly to a method for manufacturing a laminate such as a circularly polarizing plate.

  Examples of films used as laminates include packaging materials with gas barrier layers, flexible circuit boards with polyimide films laminated on copper foil, adhesive tapes with laminated adhesive sheets, polyvinyl alcohol and triacetyl cellulose dyed with iodine. Examples include laminated polarizing plates.

  As one method for producing such a laminate, Patent Document 1 discloses a method using transfer. Patent Document 1 discloses a method for manufacturing a laminate in which a protective film, a liquid crystal layer, and a quarter-wave plate are laminated via an adhesive layer. However, this document only describes the transfer order of each layer of the laminate. Actually, if the adhesiveness between the pressure-sensitive adhesive layer and the layer to be transferred is not adjusted, transfer may not be performed as expected during transfer. Further, if the force is excessively applied when the transferability is poor, a change in physical properties may occur in the layer to be transferred. Further, when the layer to be transferred is thin, there may be a problem that it is torn. Moreover, this patent document 1 does not describe a continuous laminate manufacturing method.

  Patent Document 2 also describes a method for producing a polarizing plate with an optical compensation layer using transfer, but since this method is also unclear about transfer properties, there is a problem that the layer is broken or changes in physical properties during transfer. .

Moreover, it is essential to laminate | stack the laminated body of a polarizing plate and retardation film called a circularly-polarizing plate, strictly controlling the bonding angle. When the bonding angle is deviated, the optical properties of the circularly polarizing plate, which is called ellipticity, are deteriorated. As disclosed in Patent Document 3, a conventional circularly polarizing plate is cut after one laminated body, and then bonded to a predetermined angle, and the other laminated body is cut. However, there is a problem in that productivity does not increase because it is necessary to bond the sheet-fed film with accurate angle control. Moreover, in the case of a film having poor handleability such as a thin film or a fragile film, there has been a problem that a bonding angle is shifted during lamination.
JP 2003-227936 A JP 2004-145139 A Japanese Patent Laid-Open No. 11-95028

  The present invention has been achieved as a result of studying the above-described problems in the prior art as problems. That is, an object of the present invention is to provide a continuous laminate manufacturing method in which the conveying bodies are laminated at different lamination angles, and at the same time, the layers constituting the laminate are produced when the laminate is produced. It is an object of the present invention to provide a method for suppressing physical property changes and layer breakage of a layer to be transferred by controlling transferability.

  In order to achieve the above object, a method for manufacturing a laminate according to the present invention includes a first intermittent conveyance step in which a first conveyance body is intermittently conveyed along a first conveyance axis, and a first intermittent conveyance step. In synchronization with the first transport axis, the second transport body is transported so as to overlap the first transport body along the second transport axis at an angle different from that of the first transport shaft (for example, transport under the first transport body) Production of a laminate having a second intermittent conveyance step and a lamination step of laminating part or all of the first and second overlapping portions where the first conveyance body and the second conveyance body overlap each other. In the method, the second carrier is formed by laminating at least two layers of a first layer and a second layer having a peel strength between layers of 0.03 to 0.30 N / 25 mm. After laminating the first carrier and the first layer in the second overlapping portion, peeling off the first layer and the second layer It comprises a method, characterized by producing the first carrier and the stack of the first layer.

  In this method for manufacturing a laminate, the ratio of (peel strength between first carrier and first layer) / (peel strength between first layer and second layer) is preferably 10 or more.

  Moreover, the manufacturing method of the laminated body which concerns on this invention is suitable especially when a 1st conveyance body and a 1st layer are optical materials.

  In the method for manufacturing a laminate according to the present invention, examples of the range of angles formed by the first transport shaft and the second transport shaft include the following optimal angle ranges. That is, when the first transport body is a polarizing plate or a laminate of a polarizing plate and a retardation film, and the first layer is a retardation film, the angle formed by the first transport axis and the second transport axis. Is 10 ° or more and 20 ° or less, or the first carrier is a polarizing plate or a laminate of a polarizing plate and a retardation film, and the first layer is a retardation film, When the angle formed by the transport shaft and the second transport shaft is 70 ° or more and 80 ° or less, or when the first transport body is a polarizing plate and the first layer is a retardation film, The angle formed by the conveyance axis and the second conveyance axis is 40 ° or more and 50 ° or less.

  According to the present invention, as described below, a laminated body can be continuously produced while providing an angle to the two conveying bodies, and further, by improving transferability when producing the laminated body, the thin film It is advantageous for transferring a layer having poor handleability such as a layer or a fragile layer. Therefore, it becomes possible to reduce defects in the laminated body such as layer breakage and physical property change.

Hereinafter, preferred embodiments of the present invention will be described.
1-3 is a schematic block diagram which shows an example of the manufacturing method of the laminated body which concerns on this invention. (A-1) of FIG. 1 shows the first stage, and shows a state in which the second carrier 2 is arranged at a predetermined angle under the first carrier 1 such as a polarizing plate. FIG. Moreover, (A-2) of FIG. 1 is the figure which looked at the schematic of the same manufacturing method from the side. The 1st conveyance body 1 and the 2nd conveyance body 2 are intermittently conveyed from the unwinding rolls 9 and 11 to the direction of the arrow with the winding rolls 10 and 12. FIG.

  (A-3) in FIG. 1 is a cross-sectional view of the second carrier 2, and the first layer 3 to be transferred to the first carrier 1 side, such as a retardation film, is transferred via the adhesive layer 6. 2 layer 4 is laminated. Here, the second transport body 2 is a first layer 3 to be transferred to the first transport body 1 side as shown in a cross-sectional view of an example of the second transport body 2 in FIG. It is preferable that only a part is half-cut (punched) [8 of (A-4)]. As a result, after the first carrier 1 and the second carrier 2 are stacked, the first carrier 3 is necessary when the first layer 3 is peeled off from the adhesive layer 6 on the second layer 4. This is because only the first layer 3 having a size can be transferred.

  In FIG. 1A-1, the state after intermittently operating the first carrier 1 and the second carrier 2 in the direction of the arrow is the state of FIG. In the portion where the first transport body 1 and the second transport body 2 overlap (the first-second overlapping portion 5), the first transport body 2 is below the first transport body 1 on the first layer 3 side. Are laminated. In this case, it is preferable to provide an adhesive layer below the first carrier 1 or on the first layer 3 in the second carrier 2. In particular, as shown in a cross-sectional view of an example of the second carrier 2 in FIG. 2B-2, an adhesive layer 7 is provided on the first layer 3, and a half cut 8 is applied to the first layer 3 portion. (Punching out) is preferable. That is, the second transport body 2 is a laminate including the adhesive layer 7, the first layer 3, the adhesive layer 6, and the second layer 4, and the portion to be transferred is the upper adhesive layer 7 and the first layer. It is preferable to use a half cut 8 (punched) up to 3. Moreover, as the 2nd conveyance body 2, a 2nd conveyance body is transported as a roll-shaped laminated body by setting it as the laminated body which consists of a protective film, an adhesive layer, a 1st layer, an adhesive layer, and a 2nd layer. Also preferred is a method of peeling off the protective film when the first carrier and the second carrier are laminated by storage and use.

  Here, the first intermittent conveyance step is the intermittent operation of the first conveyance body 1 in the direction along the first conveyance axis (the direction of the arrow in (A-1) in FIG. 1 and (B-1) in FIG. 2). This is a step of moving the first layer 3 to a place where the first layer 3 is desired to be transferred for each synchronization operation. The second intermittent transfer step is a direction along the second transfer axis in synchronization with the intermittent operation of the first transfer body 1 (in the direction (A-1) in FIG. 1, the arrow in FIG. 2 (B-1)). Direction), and a new first layer 3 to be transferred to the first carrier 1 is moved directly below the first carrier 1 for each synchronization operation.

  By this second intermittent conveyance step, the first layer 3 is positioned directly below the first conveyance body 1, but the second conveyance body 2 is configured as shown in FIG. 2 (B-2). In this case, a new adhesive layer moves immediately below the first carrier 1 for each synchronization operation. Further, when the second transport body 2 having no adhesive layer on the first layer 3 is used, the adhesive layer is placed in a state where the first layer 3 is located directly below the first transport body 1. It is also preferable that the first carrier 1 and the first and second overlapping portions 5 of the first layer 3 are applied and laminated, or an adhesive layer is applied beforehand under the first carrier 1.

  In the state of (B-1) in FIG. 2, in the first and second overlapping portions 5, the first transport body 1 and the second transport body are formed by pressure contact means (not shown) such as a pair of bonding rolls. 2 are bonded and laminated together. The state where the first carrier 1 and the second carrier 2 are laminated is (B-3) in FIG. Subsequently, by peeling between the first layer 3 and the adhesive layer 6 on the second layer 4, the target laminate 1 composed of the first carrier 1 and the first layer 3 [(( B-4)] can be manufactured. At this time, only the first layer 3 having a size to be transferred can be transferred by performing half-cut 8 (punching) as shown in FIG.

  Thereafter, the first transport body 1 is moved intermittently along the first transport axis, and the second transport body 2 is moved along the second transport axis. -1). In (C-1) of FIG. 3, reference numeral 13 denotes a portion where the first layer 3 is transferred under the first carrier 1, and reference numeral 14 denotes that the first layer 3 is transferred from the second carrier 2. Each lost part is shown. (C-2) and (C-3) in FIG. 3 show cross sections of these portions 13 and 14, respectively. In the same manner as described above from this state, in the first to second overlapping portions 5, the first carrier 1 and the second carrier 2 are bonded and laminated to each other, and the first layer 3 and the second layer are further laminated. By peeling the adhesive layer 6 on 4, a new laminated body composed of the first transport body 1 and the first layer 3 can be manufactured. A laminate can be obtained.

  The intermittent operation (synchronous operation) of each conveyance body can be performed by intermittently driving a winding roll of the conveyance body. At this time, by providing a sprocket hole at the end of the transport body or arranging a marker by printing or the like, the transport distance can be precisely controlled, and the manufacturing efficiency and quality of the laminate can be improved. .

  In the present invention, it is important that the first transport body and the second transport body are continuously supplied by intermittent operation. Thereby, it is possible to manufacture a laminated body continuously with high accuracy. Although the method for supplying a conveyance body continuously is not specifically limited, As a conveyance body, it is preferable to use a roll-shaped conveyance body for a 1st conveyance body and a 2nd conveyance body. As a roll-shaped 2nd conveyance body, it can comprise by using a roll-shaped film for a 2nd layer at least. And it is preferable to convey this roll-shaped conveyance body by what is called a roll to roll system conveyed with the conveying apparatus which has an unwinding part and a winding-up part.

  Here, the second carrier in the present invention is formed by laminating at least two layers (first layer and second layer) having a peel strength of 0.03 to 0.30 N / 25 mm. When the peel strength between the first layer and the second layer is greater than 0.30 N / 25 mm, the first carrier and the first layer are laminated, and then the first layer and the second layer are peeled off. In this case, the first layer and the second layer may not be peeled off, which is not preferable. In addition, if a force is applied forcibly to peel off, a physical property change may occur in the layer due to the applied force. For example, when the first layer is a retardation layer, the controlled retardation may change by applying force, which is not preferable. Further, when the first layer to be transferred is a thin film or is brittle, the layer may be broken by applying force. In that case, since the first layer torn is laminated in the laminated body composed of the first transport body and the first layer finally obtained, it is not preferable.

  If the peel strength between the first layer and the second layer is less than 0.03 N / 25 mm, the adhesion between the first layer and the second layer is too weak, and the This is not preferable because the first layer and the second layer may peel off. In this case, it takes time to determine the stacking position of the first transport body and the second transport body, and it may be misaligned, which is not preferable. In this case, air bubbles or peeling may occur between the layers during storage of the second carrier.

  Therefore, the peel strength between the first layer and the second layer is 0.03 N / 25 mm or more and 0.30 N / 25 mm or less. By setting it as this range, it becomes easy to transfer a 1st layer to a 1st conveyance body, and to manufacture a laminated body. More preferably, the peel strength between the first layer and the second layer is 0.05 N / 25 mm or more and 0.20 N / 25 mm or less, and particularly preferably 0.08 N / 25 mm or more and 0.15 N / 25 mm or less.

  As a method for setting the peel strength between the first layer and the second layer within the above range, a normal pressure-sensitive adhesive may be used, and the type and thickness of the pressure-sensitive adhesive may be appropriately selected.

  Specific examples of the adhesive include styrene butadiene rubber, butyl rubber, natural rubber, silicone rubber, polyisoprene, polybutene, polyvinyl ether, acrylic, polyester, oxetane, and the like. Acrylic and rubber-based pressure-sensitive adhesives are preferred because they can exhibit appropriate adhesive strength. As a film thickness, 1-50 micrometers is preferable, More preferably, it is 1-10 micrometers.

  In the present invention, the (peel strength between the first carrier and the first layer) / (peel strength between the first layer and the second layer) is preferably 10 or more. If (Peel strength between first carrier and first layer) / (Peel strength between first layer and second layer) is less than 10, after laminating first carrier and first layer, When the first layer and the second layer are to be peeled off, the first carrier and the first layer are weakly bonded, so that the first carrier and the first layer are misaligned. Or may peel off depending on circumstances.

  Therefore, if (the peel strength between the first carrier and the first layer) / (the peel strength between the first layer and the second layer) is 10 or more, the first carrier and the second carrier are After lamination, it becomes easier when the second layer is peeled off, and it is possible to prevent air bubbles and the like from being mixed between the first carrier and the first layer, and the first layer in the finally obtained laminated body This is preferable because the adhesion between the carrier and the first layer is sufficient. More preferably, (peel strength between the first carrier and the first layer) / (peel strength between the first layer and the second layer) is 50 or more, particularly preferably 100 or more.

  In the present invention, from the second layer side of the second carrier, the first carrier and the first layer are stacked while fixing the second carrier, and the first layer and the second layer are laminated. It is preferable to peel the layer.

  When laminating the first carrier and the second carrier and subsequently peeling the first layer and the second layer, it is preferable that the position of the second carrier is fixed firmly. For example, in the production of a circularly polarizing plate, a polarizing plate is used as the first carrier, and a retardation film is used as the first layer. At this time, if the second transport body is displaced from the second transport shaft by the pressure contact means such as a bonding roll, and the positional relationship between the first transport body and the first layer is displaced, the circle The lamination angle of the polarizing plate and the retardation film in the polarizing plate is shifted, and the circular polarizing plate having sufficient physical properties may not be obtained. Further, in the case where the second transport body is configured to have an adhesive layer and its protective film on the first layer, the first transport body and the first transport body after peeling off the protective film immediately before lamination with the first transport body It will be laminated. At this time, the angle adjusted when the protective film is peeled off may be shifted, and the lamination angle of the polarizing plate and the retardation film may be shifted, so that a circularly polarizing plate having sufficient physical properties may not be obtained. For this reason, it is important to firmly fix the conveyance body and suppress the positional deviation. Here, when the second transport body is strongly fixed by increasing the tension at both ends of the second transport body, physical property changes may occur in the first layer in the second transport body. In particular, when the first layer is a retardation layer made of a liquid crystal or a retardation film, a change in retardation can occur due to the applied tension.

  Therefore, as shown in FIG. 4 (A), the second carrier 2 is fixed from the second layer 4 side of the second carrier 2 to give a strong tension to the second carrier. This is preferable because the second transfer body can be fixed without being fixed. In order to fix the 2nd conveyance body 2 from the 2nd layer 4 side of the 2nd conveyance body 2, the method of attraction | suction adsorption is mentioned, However, It is not limited to this. In FIG. 4A, 11 is an unwinding roll of the second carrier 2, 12 is a winding roll of the second carrier 2 that has lost the first layer 3, and 15 is a second carrier. Two suction stands are shown respectively.

  For suction suction, as shown in FIG. 4B, which is a top view of FIG. 4A, a structure that adsorbs the transport body 2 from the second layer 4 side of the second transport body 2 is used. (16 indicates the suction and adsorption portion of the second carrier 2). The diameter of the suction hole at the suction site is preferably 0.1 cm to 3 cm. If it is larger than 3 cm, the second carrier 2 is locally stressed, and therefore there is a case where a trace of the diameter remains on the carrier 2, which is not preferable. On the other hand, if it is less than 0.1 cm, the suction force may become weak, which is not preferable. Further, the ratio of the area of the suction site to the area of the non-suction site in the first to second overlapping portions is 0.0004 ≦ (total area of the suction site) / (area of the non-suction site) ≦ 0.5. Is preferred. If it is smaller than 0.0004, the second conveying member cannot be fixed sufficiently because the suction force is insufficient. Moreover, when larger than 0.5, since a suction part is too wide, it may not fully bond by press-contacting means, such as a bonding roll. There is also a problem that the strength of the apparatus becomes insufficient. Moreover, when fixing by suction adsorption, it is preferable to use a porous sheet for the suction surface on the suction site. The use of a porous sheet is preferable because local stress is not applied to the carrier even when the diameter of the suction site is large. In the case of using a porous sheet, it is preferable from the point that no significant problem occurs even if the pore size is 3 cm or more. Although it does not specifically limit as a porous sheet, Polyethylene, a polypropylene, etc. are used from the point of cost or availability.

An optical material is preferably used as the first carrier and the first layer in the present invention.
In particular, as the first carrier, anisotropic films such as polarizing plates, retardation films, optical compensation films, viewing angle widening films, reflectors, diffusers, light guide plates, retardation plastic substrates, and the like It can be used for a laminate having one or more films, a plastic liquid crystal cell in which a liquid crystal compound is held in an isotropic film, a liquid crystalline optical compensation film, and the like.

  In addition, as a first layer, a polarizing plate, a retardation film, an optical compensation film, a viewing angle widening film, a reflecting plate, a diffusion plate, a light guide plate, a retardation plastic substrate, and a laminate having one or more of these anisotropic films Alternatively, it can be used for a plastic liquid crystal cell, a liquid crystal optical compensation film, and a liquid crystal retardation layer in which a liquid crystal compound is held in an isotropic film. In particular, a thin film, a retardation film that is brittle and has poor handleability, a liquid crystalline retardation layer formed on the second layer, and the like are preferably used.

  Here, the polarizing plate has a function of selectively transmitting one-way linearly polarized light from natural light, and examples thereof include an iodine-based polarizing plate, a dye-based polarizing plate, and a reflective polarizing plate.

  The retardation film is a substance having a difference in light transmission speed depending on the direction. The thickness of the retardation film is preferably 1 μm to 100 μm. More preferably, it is 2 μm to 50 μm. When the thickness is less than 1 μm, the phase difference controlled by a slight force such as a tension during conveyance may change. On the other hand, when the thickness is larger than 100 μm, since the handleability of the retardation film alone is excellent, the advantage of using the laminating method of the present invention is small. Also, since optical materials are currently required to be thin, a thickness exceeding 100 μm is not preferable. Examples of the retardation film include, but are not limited to, cyclic polyolefin, polyethylene, polypropylene, polycarbonate, polyester, polyvinyl alcohol, polystyrene, polymethyl methacrylate, polyarylate, polyamide, and aramid.

  Since the second layer is a layer for transporting the first layer, any film can be used without any particular limitation. However, from the viewpoint of cost, a polyethylene terephthalate (PET) film, a polyethylene film, and a polypropylene can be used. A film or the like is preferably used. The thickness of the second layer is not particularly limited, but is preferably 30 μm or more and 500 μm or less. If the thickness is less than 30 μm, when the half-cut (punching) is performed before the second layer, if the half-cut (punching) accuracy is not sufficient, the second layer may be partially cut off, which is not preferable. On the other hand, when the thickness is larger than 500 μm, the second carrier becomes too thick and the handling property is inferior, and the thickness increases, and thus the cost increases.

  In the present invention, the number of laminated films used for the first carrier is not particularly limited. Therefore, after laminating the first carrier and the first layer, using the obtained laminate as a new first carrier, repeating the lamination with the new first layer, can do. The number of layers of the finally obtained laminate is 2 to 10 layers, more preferably 2 to 3 layers. As the number of layers increases, there are problems such as bubbles entering during lamination, and therefore two to three layers are preferred.

  For example, the state of FIG. 5A is the first carrier 1 and the first layer 3 when the polarizing plate 19 is used for the first carrier 1 and the retardation film 20 is used for the first layer 3. FIG. 5B shows a configuration of a laminated body made of a single retardation film bonded to the first carrier 1 via a polarizing plate 19 and an adhesive layer 17. 20 is a configuration example of a laminated body including the first transport body 1 and the first layer 3 in the case where a single retardation film 20 is used for the laminated body and the first layer 3. Similarly, a laminated body can be used as the first layer. For example, the state of FIG. 3C uses a laminate of two retardation films 20 bonded to each other through the polarizing plate 19 and the first layer 3 through the adhesive layer 18 on the first carrier 1. The structure of the laminated body which consists of the 1st conveyance body 1 and the 1st layer 3 is shown.

The angle of the conveying shaft in the present invention is appropriately set depending on the application.
For example, in a narrow-band circular polarizer or a broadband circular polarizer composed of one polarizer and one quarter-wave retardation film, the retardation film has a slow axis of 45 ° ± with respect to the absorption axis of the polarizer. It is preferable to bond at 5 °. Therefore, in this case, a ¼ wavelength retardation film having an absorption axis as the first transport body along the first transport axis and a slow axis as the first layer in the second transport axis direction. The angle formed by the first conveyance axis and the second conveyance axis is controlled to 45 ° ± 5 ° using the second conveyance body using the In this case, a second transport body using a quarter wavelength retardation film having a slow axis in a direction orthogonal to the second transport axis may be used as the first layer. Here, the angle formed by the first conveyance axis and the second conveyance axis is an angle indicated by 21 in FIG. 6A and indicates that this angle is 45 ° ± 5 °.

  In a broadband circularly polarizing plate composed of one polarizing plate, one half-wave retardation film, and two retardation films of one quarter-wave retardation film, it is ½ with respect to the absorption axis of the polarizing plate. The slow axis of the wavelength retardation film is 15 ° ± 5 °, and the slow axis of the quarter wavelength retardation film is 75 ° ± 5 ° with respect to the absorption axis of the polarizing plate. Therefore, in this case, a ½ wavelength retardation film having an absorption axis as the first transport body along the first transport axis and a slow axis as the first layer in the second transport axis direction. Using a second transport body using the above, the angle formed by the first transport shaft and the second transport shaft is controlled to 15 ° ± 5 °, and the polarizing plate and the half-wave retardation film are laminated. A laminate is produced. That is, in this case, the angle 21 in FIG. 6A is 15 ° ± 5 °.

  Subsequently, as the first transport body, a laminate of the above-described polarizing plate and a half-wave retardation film, and as the first layer, a quarter-wave retardation film having a slow axis in the second transport axis direction. The angle formed by the first transport shaft and the second transport shaft is controlled to 75 ° ± 5 ° using the second transport body used. That is, in this case, the angle 21 in FIG. 6A is 75 ° ± 5 °.

  Further, in this case, a polarizing plate having an absorption axis along the first conveyance axis as the first conveyance body, and a ½ wavelength phase difference having a slow axis as the first layer in a direction orthogonal to the second conveyance axis. Using the second transport body using the film, the angle formed by the first transport shaft and the second transport shaft is 75 ° ± 5 ° (the angle 21 in FIG. 6A is 75 ° ± 5 °). Next, a quarter wavelength retardation having a controlled layer and a laminate of a polarizing plate and a half wavelength retardation film as a first transport body and a slow axis as a first layer in a direction perpendicular to the second transport axis. Using the second transport body using a film, the angle formed by the first transport shaft and the second transport shaft is 15 ° ± 5 ° (the angle 21 in FIG. 6A is 15 ° ± 5 °). It can also be controlled.

  As another embodiment of the present invention, FIG. 6B shows a method of stacking three or more types of transport bodies to obtain a stack. For example, in the production of a broadband circularly polarizing plate comprising one polarizing plate, one half-wave retardation film, and two retardation films of one quarter-wave retardation film, as shown in FIG. In one manufacturing apparatus, the stacking process of the first transport body 1 and the first second transport body 22 and the first transport body 1 and the first second transport body 22 Lamination process of the laminated body composed of one layer (half-cut first layer 23) and the second second carrier 27 (half-cut second of the second second carrier 27) It is also possible to provide an apparatus having two stacking steps having a stacking step with one layer 28). In FIG. 6B, 24 is the first first-second overlapping portion, 29 is the second first-second overlapping portion, and 25 is the second from the first second carrier. A portion where one layer is lost by transfer, 26 is a portion where the first first layer is transferred under the first carrier, and 30 is a portion where the first layer is transferred from the second second carrier. A portion lost by the transfer, 31 is a portion where the second first layer is transferred under the first carrier, 32 is an angle formed by the first carrier and the first second carrier, 33 Indicates the angles formed by the first carrier and the second second carrier, respectively.

  For example, a polarizing plate having an absorption axis along the first transport axis as the first transport body, and a slow axis as the first second transport shaft as the first layer of the first second transport body Wavelength retardation film having a slow axis as a first layer of the second second transport body and a quarter wavelength having a slow axis in a direction orthogonal to the second second transport axis It is assumed that a retardation film is used.

  In this case, the angle 32 formed by the first conveyance axis and the first second conveyance axis is controlled to 75 ° ± 5 °. The first layer side of the second carrier is stacked below the first carrier at the portion where the first carrier and the second carrier overlap (first-second overlapping portion 24). That is, a polarizing plate and a half-wave retardation film are laminated. In this case, it is preferable to provide an adhesive layer under the first carrier or on the first layer in the second carrier, but more preferably as the second carrier on the first layer. It is to provide an adhesive layer. Subsequently, the first layer and the second layer in the first second carrier are peeled off. When the first transport body and the second transport body are intermittently operated while repeating these steps, the first transport body having the first layer overlaps with the second second transport body. 29 is generated. Here, as in the case of the first second transport body and the first transport body, the second second transport body and the first transport body are laminated and peeled off. A laminated body in which the first transport body, the first first layer, and the second first layer are laminated is obtained. Here, the angle 33 formed by the first conveyance axis and the second second conveyance axis is controlled to 15 ° ± 5 °. In this manner, three or more types of transport bodies (polarizing plate, laminated body of half-wave retardation film and quarter-wave retardation film) are laminated to produce a circularly polarizing plate.

  Here, the circularly polarizing plate is configured by laminating a polarizing plate and a retardation film. The circularly polarizing plate is a laminate having a function of converting linearly polarized light into circularly polarized light or converting circularly polarized light into linearly polarized light. These circularly polarizing plates are used as essential constituent members of a reflective liquid crystal display device, or are used in an organic EL display device or the like to suppress the reflection of light on the surface of the display body and increase the contrast.

  The example of the manufacturing method of the 2nd conveyance body used when manufacturing the laminated body of a polarizing plate and retardation film is described. The roll-like retardation film as the first layer and the roll-like polyethylene terephthalate (PET) film with a fine adhesion layer as the second layer are bonded in parallel using a film laminator as shown in FIG. . In FIG. 7, reference numeral 34 denotes a retardation film (first layer) or an unwinding roll of a film with an adhesive layer, and 35 denotes a polyethylene terephthalate film with a fine adhesive layer (second layer) or a retardation film (first film). Layer) and a polyethylene terephthalate film (second layer) unwinding roll, 36 is a retardation film (first layer) or a bonding roll on the film side with an adhesive layer, and 37 is polyethylene terephthalate with a microadhesive layer. A laminating roll on the laminate side of a film (second layer) or retardation film (first layer) and a polyethylene terephthalate film (second layer), 38 is a retardation film (first layer) and a polyethylene terephthalate film (Second layer) laminate or retardation film (first layer) and polyethylene terephthalate film (first layer) Layer) and the winding roll of the laminate of the adhesive layer provided films, respectively.

  The stacked body thus obtained has a structure shown in FIG. Subsequently, on the first layer side of the laminate composed of the first layer (retardation film) and the second layer (PET film), a roll-formed film with an adhesive layer (this film is bonded to the second carrier). Are laminated in parallel with a film laminator machine shown in FIG. The stacked body thus obtained has a structure shown in FIG. 8B-1 and 8B-2, 39 is a retardation film (first layer), 40 is a polyethylene terephthalate film (second layer), 41 is a slightly adhesive layer, and 42 is protection. A film 43 indicates an adhesive layer.

  Since the adhesive layer laminated on the first layer is finally used for bonding between the polarizing plate as the first carrier and the retardation film as the first layer, It is necessary to select an adhesive layer excellent in both adhesive properties of the retardation film. By cutting edge portions at both ends of the laminated body to make the widths of the respective layers in the laminated body uniform, and further half-cutting the first layer to a required size, the second carrier is manufactured. Subsequently, the second carrier (protective film + adhesive layer + retardation film (first layer) + fine adhesion layer + PET film (second layer)) is transferred to the first carrier by the method described above. By laminating with a certain polarizing plate, a laminate of the polarizing plate and the retardation film can be produced. In this case, a step for peeling off the protective film on the first layer of the second carrier is required before or after the laminating step of the first carrier and the second carrier.

  Examples of the method of half-cutting (punching) up to the first layer in the second carrier include punching using a mold such as a Thomson blade, punching with a laser, cutting with a moving blade, cutting with a diamond blade, etc. Punching using is preferably used. The shape of the first layer 44 that is half-cut in the second carrier is a quadrangle shown in FIGS. 9A-2 and 9A, or a hexagonal system shown in FIG. 9A-4. A square shape, a circle, or the like can be used, and the laminated portion 45 including the first transport body and the first layer obtained in this case is shown in FIGS. 10 (B-2), (B-3), (B -4). However, as shown in FIG. 9 (A-1), it is possible to obtain a parallelogram that matches the size of the second carrier and the angle to be bonded to the first carrier. As shown in 1), it is preferable because the loss of the conveyance body is reduced. Note that the double-headed arrows in FIGS. 9 and 10 indicate the slow axis of the first layer.

  As the adhesive layer disposed between the first carrier and the first layer, or the adhesive layer between the first layer and the second layer, an adhesive or pressure sensitive adhesive described later is used. Examples of these coating methods include roll coaters, bar coaters, die coaters, spray guns, flexographic printing, screen printing, and transfer of adhesive sheets. In particular, as the adhesive layer disposed between the first carrier and the first layer, the first carrier may be provided with an adhesive layer, or the first layer may be provided with an adhesive layer. When producing the 2 conveyance body, it is preferable to comprise the 2nd conveyance body with an adhesive layer using an adhesive sheet on the 1st layer side. Moreover, you may provide the application | coating process of an contact bonding layer before the lamination process of a 1st conveyance body and a 2nd conveyance body.

In addition, the first carrier and the first layer can be laminated by using an adhesive or a pressure-sensitive adhesive by being crimped or irradiated with light at room temperature or while heating, but immediately after bonding with a bonding roll or the like. This is preferable because the air bubbles between the two layers can be removed, and the layered body composed of the first carrier and the first layer finally obtained has no defects.

  Adhesives used for the adhesive layer include urea resin, melamine resin, phenol resin, resorcinol resin, epoxy, polyurethane resin, vinyl acetate resin, polyvinyl alcohol resin, acrylic, oxetane, cellulose Resin adhesives such as resin, chloroprene, nitrile rubber, styrene butadiene rubber, styrene block copolymer thermoplastic elastomer, butyl rubber, natural rubber, recycled rubber, chlorinated rubber, silicone rubber, etc. Examples thereof include rubber adhesives.

  An adhesive is also used for the adhesive layer. This pressure-sensitive adhesive is a kind of adhesive generally referred to as a pressure-sensitive adhesive. Specific examples include styrene butadiene rubber, butyl rubber, natural rubber, silicone rubber, polyisoprene, polybutene, polyvinyl ether, acrylic, polyester, oxetane, and the like.

  In addition, the adhesive layer between the first layer and the second layer not only defines the peel strength, but the adhesive layer does not remain on the first layer after the first layer is peeled off from the second layer. Is preferred. For this purpose, an adhesive layer excellent in compatibility with the second layer should be selected as the adhesive layer between the first layer and the second layer.

  Hereinafter, the present invention will be described based on examples. The measurement method of the present invention was performed according to the following method.

(1) Peel strength between first layer and second layer Based on JIS K6854-3 (adhesive-peel adhesion strength test method-Part 3: T-type peel), the first layer and the second layer The peel strength of the layer was measured. The width of the test piece was 25 mm, and the grip moving speed was 100 mm / min.

(2) (Peel strength between first carrier and first layer) / (Peel strength between first layer and second layer) JIS K6854-3 (Adhesive-Peel adhesive strength test method-Third Part: T-type peeling), the peel strength between the first carrier and the first layer was measured. The width of the test piece was 25 mm, and the grip moving speed was 100 mm / min. The obtained value was divided by the peel strength between the first layer and the second layer to obtain the desired value.

(3) Evaluation of Laminate Consisting of First Conveying Body and First Layer The conveying body and the laminated body were visually observed to check for defects. When a 1 m laminate was produced, it was evaluated according to the following criteria.
Location where the first layer in the laminate is torn = 0: ○, 1 or more: ×
When a 1-m second carrier is wound around a 6-inch core, peeling between the first layer and the second layer in the laminate as the second carrier: 0 to 2 pieces: ◯, 3 or more : ×
Position misalignment where the widthwise end of the first carrier in the laminate and the widthwise end of the first layer in the laminate are 0.5 cm or more = 0-2: ○, 3 or more: ×

(Example 1)
A 75 μm-thick polyvinyl alcohol (PVA) film was swollen in a 30 ° C. hot water bath, stretched about 3 times in a 30 ° C. dyeing bath composed of an aqueous solution of iodine and potassium iodide, and then 50 The film was stretched and cross-linked in a cross-linking bath composed of a boric acid aqueous solution at 0 ° C. so that the total draw ratio was 6 times. This was immersed in an aqueous solution of potassium iodide at 35 ° C. for 10 seconds to adjust the hue. Further, it was washed with water and dried to obtain a polarizing film having a thickness of 16 μm. The moisture content of the PVA polarizer was 15% by weight. Next, an adhesive composed of 7% by mass of PVA aqueous solution was applied to both sides of the PVA polarizer, and the adhesive surface was washed with an aqueous caustic soda solution as a protective film. A polarizing plate with a protective film on both sides having a total thickness of 98 μm was prepared by laminating a 40 μm thick triacetylcellulose (TAC) film. The obtained polarizing plate had a single transmittance of 43.4% and a polarization degree of 99.9%. The polarizing plate thus obtained was cut into a width of 120 mm to obtain a first carrier.

  Next, a bisphenol A type polycarbonate film was stretched in the film flow direction at 155 ° C., so that the phase difference at 550 nm was 138 nm. The obtained stretched polycarbonate film had a thickness of 50 μm, the slow axis was the stretching direction, and this film was used as the first layer.

  As a second layer, a slimliner SRL-0753B (AS) (thickness 75 μm) manufactured by Lintec Co., Ltd., which is a PET film with one side slightly adhesive layer, was used.

  The first layer and the second layer are laminated, and a supportless adhesive sheet SK1478 made by Soken Chemical Co., Ltd. is further laminated on the upper side of the first layer, and an adhesive layer (thickness 25 μm) is formed thereon. An adhesive layer protective film (thickness 38 μm) was formed. This laminate was cut to a width of 120 mm. Furthermore, this laminated body was half-cut to the first layer at an angle of 45 ° with respect to the film flow direction to obtain a second transport body.

  These first transport body and second transport body were stacked at a stacking angle of 45 ° using the apparatus having the continuous stacking mechanism shown in FIG.

  When the obtained laminated body was observed, the first layer in the laminated body was free of tears and wrinkles and was excellent in appearance.

(Example 2)
100 parts / 0.2 parts (parts by weight) of acrylic adhesive “Aron Tuck” S-1511 (X) manufactured by Toagosei Co., Ltd. and “Coronate” L-75 manufactured by Nippon Polyurethane Industry Co., Ltd. Was sufficiently mixed to obtain an adhesive preparation liquid. The obtained preparation solution was applied on a 300 mm width Toyobo Co., Ltd. E-7007 (thickness 25 μm) at a coating temperature of 25 ° C. with a comma coater so that the film thickness after drying was 25 μm. Dry at 100 ° C. for 3 minutes. Thereafter, E-7006 (thickness 25 μm) manufactured by Toyobo Co., Ltd. was laminated and wound to obtain a supportless pressure-sensitive adhesive sheet A.

  The first carrier and the first layer are the same as in Example 1 except that the supportless pressure-sensitive adhesive sheet A is used as the supportless pressure-sensitive adhesive sheet laminated on the first layer in the second carrier. Were laminated.

  When the obtained laminated body was observed, the first layer in the laminated body was free of tears and wrinkles and was excellent in appearance.

(Example 3)
Polyethylene terephthalate film ["LUMIRROR" T60 (thickness: 188 μm) manufactured by Toray Industries, Inc.] as the first carrier, and aromatic polyamide film [“MICTRON” (thickness: 12 μm), manufactured by Toray Industries, Inc.] as the first layer Except for the point used, the first carrier and the first layer were laminated in the same manner as in Example 1.

  When the obtained laminated body was observed, the first layer in the laminated body was free of tears and wrinkles and was excellent in appearance.

Example 4
Toagosei Co., Ltd. acrylic adhesive “Aron Tuck” S-1601 and Nippon Polyurethane Industry Co., Ltd. “Coronate” L-75 at a ratio of 100 parts / 0.2 parts (parts by weight). The mixture was sufficiently mixed to obtain a pressure-sensitive adhesive preparation solution. The obtained preparation solution was applied on a 300 mm width Toyobo Co., Ltd. E-7007 (thickness 25 μm) at a coating temperature of 25 ° C. with a comma coater so that the film thickness after drying was 25 μm. Dry at 100 ° C. for 3 minutes. Then, supportless adhesive sheet B was obtained by laminating and winding E-7006 (thickness 25 μm) manufactured by Toyobo Co., Ltd.

  In the second carrier, the supportless adhesive sheet B obtained in Example 2 is used as the supportless adhesive sheet laminated on the first layer, and “Slim Liner” manufactured by Lintec Corporation is used as the second layer. The first carrier and the first layer were laminated in the same manner as in Example 1 except that SRL-0753 (AS) (thickness 75 μm) was used.

  When the obtained laminated body was observed, although a tear and a bubble were not generated in the laminated body, a positional deviation such that a part of the first layer protruded from the width direction of the first conveying body was observed.

(Comparative Example 1)
Toagosei Co., Ltd. acrylic adhesive “Aron Tuck” S-1601 and Nippon Polyurethane Industry Co., Ltd. “Coronate” L-75 at a ratio of 100 parts / 0.2 parts (parts by weight). The mixture was sufficiently mixed to obtain a pressure-sensitive adhesive preparation solution. The obtained preparation solution was applied onto a “Lumirror” (thickness 75 μm) manufactured by Toray Industries, Inc. having a width of 300 mm with a comma coater at a coating temperature of 25 ° C. so that the film thickness after drying was 3 μm. Dry at 3 ° C. for 3 minutes. Thereafter, E-7007 (thickness 25 μm) manufactured by Toyobo Co., Ltd. was laminated and wound up to obtain a PET film A with a one-sided slightly adhesive layer.

  The first carrier and the first layer were laminated in the same manner as in Example 1 except that the PET film A with one side slightly adhesive layer obtained here was used as the second layer.

  When the obtained laminate was observed, bubbles and sagging in the first layer were found between the first carrier and the first layer in the laminate. In addition, peeling of the second carrier used at this time was observed between the first layer and the second layer. The peeling in the second transport body is considered to be the cause of slack and bubbles between the layers of the obtained laminate.

(Comparative Example 2)
As the second layer, except for using a “slim liner” SRL-0754 (AS) (thickness 75 μm) manufactured by Lintec Co., Ltd., which is a PET film adhesively processed on one side, The 1st conveyance body and the 1st layer were laminated | stacked. When the obtained laminated body was observed, the torn part was seen by the 1st layer in a laminated body.

It is a schematic block diagram which shows the manufacturing method of the laminated body which concerns on one embodiment of this invention. It is a schematic block diagram for demonstrating an example of the step in the method of FIG. It is a schematic block diagram for demonstrating an example of another step in the method of FIG. It is a schematic block diagram which shows the conveyance example of the 2nd conveyance body in the manufacturing method of the laminated body which concerns on one embodiment of this invention. It is a schematic sectional drawing which shows the structural example of a laminated body in the manufacturing method of the laminated body which concerns on one embodiment of this invention. It is a schematic block diagram which shows the example of a manufacturing method of the laminated body which concerns on the embodiment of this invention. It is a schematic block diagram which shows the example of the manufacturing method of the 2nd conveying body in this invention. It is a schematic sectional drawing which shows the structural example of the 2nd conveyance body in this invention. It is a schematic block diagram which shows the example of a half cut shape of the 2nd conveyance body in this invention. It is a schematic block diagram which shows the structural example of the laminated body corresponding to the half cut shape example of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st conveyance body 2 2nd conveyance body 3 1st layer 4 2nd layer 5 1st-2nd overlap part 6 Adhesion layer between 1st layer and 2nd layer 7 On 1st layer Adhesive layer 8 Half cut in the second carrier (half cut line)
DESCRIPTION OF SYMBOLS 9 Unwinding roll of 1st conveyance body 10 Winding roll of laminated body 11 Unwinding roll of 2nd conveyance body 12 Winding roll of 2nd conveyance body which lost 1st layer 13 1st conveyance body The part which transferred the 1st layer below 14 The part which lost the 1st layer from the 2nd conveyance body by transfer 15 The adsorption stand of the 2nd conveyance body 16 The suction adsorption part of the 2nd conveyance body 17 The 1st Adhesive layer in carrier 18 Adhesive layer in first layer 19 Polarizing plate 20 Retardation film 21 Angle formed by first carrier and second carrier 22 First second carrier 23 First The first layer that is half-cut in the second transport body 24 The first first-second overlapping portion 25 The portion that lost the first layer from the first second transport body 26 by the transfer 26 The portion where the first first layer is transferred under the first carrier 27 The second second carrier 28 The second Half-cut first layer 29 in second carrier 29 Second first-second overlap portion 30 First layer lost from second second carrier due to transfer 31 First The portion where the second first layer is transferred under the transport body 32 The angle formed by the first transport body and the first second transport body 33 The first transport body and the second second layer Angle formed by carrier 34 Retardation film (first layer) or unwinding roll of film with adhesive layer 35 Polyethylene terephthalate film (second layer) with microadhesive or retardation film (first layer) and polyethylene Unwinding roll of laminate of terephthalate film (second layer) 36 Retardation film (first layer) or laminating roll on film side with adhesive layer 37 Polyethylene terephthalate film with fine adhesive (second layer) or Phase difference fill Laminating roll on the laminate side of (first layer) and polyethylene terephthalate film (second layer) 38 Laminate or retardation film of retardation film (first layer) and polyethylene terephthalate film (second layer) Winding roll of laminate of (first layer), polyethylene terephthalate film (second layer) and film with adhesive layer 39 Retardation film (first layer)
40 Polyethylene terephthalate film (second layer)
41 Slightly Adhesive Layer 42 Protective Film 43 Adhesive Layer 44 Half-Cut First Layer in Second Conveying Body 45 Laminated Portion of First Conveying Body and First Layer

Claims (7)

  A first intermittent conveyance step of intermittently conveying the first conveyance body along the first conveyance axis, and a second conveyance body at an angle different from the first conveyance axis in synchronization with the first intermittent conveyance step. About the second intermittent conveyance process in which the first conveyance body and the second conveyance body overlap with each other, and the second intermittent conveyance process in which the first conveyance body and the first conveyance body overlap with each other along the second conveyance axis, A method of manufacturing a laminate having a laminating step of laminating part or all of the first and second layers, wherein the second carrier has a first layer having an interlayer peel strength of 0.03 to 0.30 N / 25 mm And at least two layers of the second layer are laminated, and after the first carrier and the first layer are laminated in the first to second overlapping portions, the first layer and the second layer are peeled off. A method for producing a laminate, comprising producing a laminate comprising a first carrier and a first layer.   The manufacturing method of the laminated body of Claim 1 whose ratio of (peel strength between the 1st conveyance body and the 1st layer) / (peel strength between the 1st layer and the 2nd layer) is 10 or more.   The manufacturing method of the laminated body of Claim 1 or 2 whose 1st conveyance body and 1st layer are optical materials.   The first transport body is a polarizing plate or a laminate of a polarizing plate and a retardation film, the first layer is a retardation film, and the angle formed by the first transport axis and the second transport axis is 10 °. The manufacturing method of the laminated body in any one of Claims 1-3 which is 20 degrees or less above.   The first transport body is a polarizing plate or a laminate of a polarizing plate and a retardation film, the first layer is a retardation film, and the angle formed by the first transport axis and the second transport axis is 70 °. The manufacturing method of the laminated body in any one of Claims 1-3 which is 80 degrees or less above.   The first transport body is a polarizing plate, the first layer is a retardation film, and an angle formed by the first transport shaft and the second transport shaft is 40 ° or more and 50 ° or less. 4. A method for producing a laminate according to any one of 3 above.   The manufacturing method of the laminated body in any one of Claims 1-6 which supplies a 1st conveyance body and a 2nd conveyance body from a roll-shaped thing.

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