JP5799989B2 - Optical film, image display device, optical film transfer body, optical film manufacturing method, and optical film transfer body manufacturing method - Google Patents

Description

  The present invention relates to a circularly polarizing plate by laminating a linearly polarizing plate and a quarter-wave plate, and an optical device comprising the quarter-wave plate by laminating a half-wave retardation layer and a quarter-wave retardation layer. Related to film.

  Conventionally, regarding an image display device, a method has been proposed in which an optical film made of a circularly polarizing plate is arranged on the panel surface (viewer side surface) of an image display panel, and reflection of extraneous light is reduced by this optical film. Here, this optical film is composed of a laminate of a linear polarizing plate and a quarter-wave plate, and converts external light directed to the panel surface of the image display panel into linearly-polarized light by the linear polarizing plate, followed by a quarter-wave plate. Convert to circularly polarized light. Here, the extraneous light by the circularly polarized light is reflected by the surface of the image display panel or the like, but the rotation direction of the polarization plane is reversed during the reflection. As a result, contrary to the arrival time, this reflected light is converted into linearly polarized light in the direction shielded by the linear polarizing plate by the quarter wavelength plate, and then shielded by the subsequent linear polarizing plate. Outgoing emission is significantly suppressed.

  With regard to this optical film, Patent Document 1 and the like include a 1/2 wavelength phase difference layer that imparts a phase difference of ½ wavelength to transmitted light, and a 1 / wavelength that imparts a phase difference of ¼ wavelength to transmitted light. A method has been proposed in which a quarter-wave plate is formed by laminating four-wavelength retardation layers to use a liquid crystal material having a positive dispersion characteristic so that the quarter-wave plate functions with a reverse dispersion characteristic. Here, the reverse dispersion characteristic is a wavelength dispersion characteristic in which the phase difference in transmitted light is smaller as the wavelength is shorter.

  The half-wave retardation layer, the quarter-wave retardation layer, and the like can be created by solidifying (curing) the liquid crystal material in a state where the liquid crystal material is aligned by the alignment regulating force of the alignment film. . More specifically, this type of retardation layer is formed by laminating a polymerizable liquid crystal monomer on an alignment film, raising the temperature to the phase transition point, and then polymerizing by ultraviolet irradiation or the like to fix the alignment state of the liquid crystal. Can be produced. In addition, the alignment film can be formed by transferring a fine line-shaped uneven shape formed on the forming mold by a forming process using a forming mold, for example, or by a so-called photo-alignment technique. Can also be created.

  By the way, after a ½ wavelength phase difference layer and a ¼ wavelength phase difference layer are individually formed, and then bonded together by an adhesive layer, a ½ wavelength phase difference layer and a ¼ wavelength phase difference layer are laminated. It is thought that a quarter wave plate can be produced by the body. At this time, it is considered that the entire thickness can be reduced by directly bonding the ½ wavelength retardation layer and the ¼ wavelength retardation layer with an adhesive layer (adhesive layer). In addition, the half-wave retardation layer and the quarter-wave retardation layer laminated body thus produced are integrated with the linear polarizing plate by a transfer method, and this half-wave retardation is obtained. It is considered that the overall thickness can be reduced by directly attaching the laminate of the layer and the quarter wavelength retardation layer to the panel surface of the image display panel. The transfer method refers to, for example, when a desired layer is formed on a base material, the layer is not directly formed on the base material, but can be peeled once on a releasable support. After forming the transfer body by laminating the layers, the layer formed on the support is finally placed on the substrate (transfer base material) on which the layer is to be laminated according to the process, demand, etc. In this method, a desired layer is formed on the substrate by bonding and laminating, and then peeling and removing the support.

  However, when this is done, the retardation value in the retardation layer is lowered due to the influence of the adhesive used for attaching to the image display panel, and as a result, there is a problem that the intended optical characteristics cannot be secured due to changes over time. . More specifically, the color of the display screen is lowered. It is conceivable that the characteristics change with time. Hereinafter, such a decrease in retardation value is referred to as retardation drop.

JP-A-10-68816 JP 2000-284126 A

  The present invention has been made in view of such a situation. In a configuration in which a laminate of a ½ wavelength phase difference layer and a ¼ wavelength phase difference layer is directly arranged on the panel surface of an image display panel, The effect of retardation drop can be effectively avoided while reducing the thickness.

  In order to solve the above-mentioned problems, the present inventor has conducted intensive research, and in a laminate of a ½ wavelength retardation layer and a ¼ wavelength retardation layer, the image display panel side is provided with an alignment film as a protective layer. This led to the idea that an alignment film is not provided on the opposite side, and the present invention has been completed.

(1) In an optical film in which an adhesive layer, a quarter-wave plate, and a linear polarizing plate are sequentially laminated,
The quarter-wave plate is
Adhering a 1/2 wavelength retardation layer that gives a phase difference of 1/2 wavelength to transmitted light and a 1/4 wavelength retardation layer that gives a phase difference of 1/4 wavelength to the transmitted light by an adhesive layer The adhesive layer side is the ¼ wavelength phase difference layer,
Between the 1/4 wavelength retardation layer and the adhesive layer, an alignment film for a 1/4 wavelength retardation layer according to the 1/4 wavelength retardation layer is provided,
The half-wave retardation layer is attached to the linearly polarizing plate by an adhesive layer.

  According to (1), the retardation film of the 1/4 wavelength retardation layer due to the residual solvent of the adhesive layer is reduced by causing the alignment film for the 1/4 wavelength retardation layer to function as a protective layer of the 1/4 wavelength retardation layer. can do. On the 1/2 phase difference layer side, the influence of retardation drop is small, and by making the upper and lower layers adhesive, the influence of the residual solvent is also small. The effect of dropping can be reduced, and in these arrangements, the overall thickness is reduced in a configuration in which a laminate of a 1/2 wavelength retardation layer and a 1/4 wavelength retardation layer is directly disposed on the panel surface of an image display panel. However, the influence of retardation drop can be effectively avoided.

(2) In (1),
An antireflection coating layer and / or a hard coating layer was provided on the side surface of the linear polarizing plate opposite to the quarter-wave plate.

  According to (2), with respect to the optical film provided with the antireflection coating layer and / or the hard coating layer, the influence of the retardation drop can be effectively avoided while reducing the overall thickness.

  (3) The image display apparatus which has arrange | positioned the optical film as described in (1) or (2) on the image display panel surface by the said adhesion layer.

  According to (3), it is possible to prevent reflection with an optical film that effectively avoids the effects of retardation drops while reducing the overall thickness.

(4) A transfer body for an optical film comprising at least a support substrate and a transfer layer,
The transfer layer is from the support substrate side,
An alignment film for a quarter wavelength retardation layer according to a quarter wavelength retardation layer, the quarter wavelength retardation layer for imparting a phase difference corresponding to a quarter wavelength to transmitted light, an adhesive layer, and a transmission layer A half-wave retardation layer for providing a half-wave phase difference to the light, and the adhesive layer provides the quarter-wave retardation layer, the half-wave retardation layer, Was pasted together.

  According to (4), the retardation layer of the 1/4 wavelength phase difference layer due to the residual solvent of the adhesive layer is reduced by causing the alignment film for the 1/4 wavelength phase difference layer to function as a protective layer of the 1/4 wavelength phase difference layer. can do. Further, on the 1/2 phase difference layer side, the influence of retardation drop is small, and the influence of the residual solvent can be reduced by making the upper and lower adhesive layers, thereby eliminating the need for providing an alignment film. In the configuration in which the influence of retardation drop can be sufficiently reduced, and the laminate of the ½ wavelength retardation layer and the ¼ wavelength retardation layer is directly arranged on the panel surface of the image display panel. The effect of retardation drop can be effectively avoided while reducing the thickness.

(5) In (4), on the side opposite to the adhesive layer of the 1/2 wavelength retardation layer, the alignment film for 1/2 wavelength retardation layer according to the 1/2 wavelength retardation layer, and the 1 / 2 wavelength retardation layer, a substrate on the 1/2 wavelength retardation layer side holding the alignment film for the 1/2 wavelength retardation layer, and
The half-wave retardation layer and the alignment layer for the half-wave retardation layer were prepared so as to have the smallest adhesive strength between other portions.

  According to (5), at the time of bonding with the linearly polarizing plate, the substrate on the ½ wavelength retardation layer side is peeled off integrally with the alignment film for ½ wavelength retardation layer, and directly ½ A wavelength retardation layer can be attached to a linearly polarizing plate with an adhesive layer, whereby an optical film comprising an alignment film for a ½ wavelength retardation layer and a substrate on the ½ wavelength retardation layer side With respect to the transfer body, the influence of retardation drop can be effectively avoided while reducing the overall thickness.

(6) an optical film transfer body producing step for producing an optical film transfer body;
A bonding step according to a linearly polarizing plate, wherein the optical film transfer body is bonded to a linearly polarizing plate to produce a laminate of the optical film transfer body and the linearly polarizing plate;
A support substrate peeling step in which the support substrate of the optical film transfer member is peeled from the laminate of the optical film transfer member and the linearly polarizing plate, and the adhesive layer and the separator film are sequentially disposed,
The transfer film production process for the optical film,
An alignment film for a quarter-wave retardation layer according to a quarter-wave retardation layer on the support substrate, and the quarter-wave retardation for imparting a quarter-wave phase difference to transmitted light. A quarter wavelength phase difference layer manufacturing step of sequentially manufacturing layers and manufacturing a quarter wavelength phase difference layer side laminate;
On the base on the 1/2 wavelength phase difference layer side, the alignment film for 1/2 wavelength phase difference layer related to the 1/2 wavelength phase difference layer and the phase difference for 1/2 wavelength are given to the transmitted light A step of producing a ½ wavelength phase difference layer in which a ½ wavelength phase difference layer is sequentially produced to produce a laminate on the side of the ½ wavelength phase difference layer;
A bonding step according to a quarter-wave plate for producing a quarter-wave plate by bonding the quarter-wave retardation layer and the half-wave retardation layer with an adhesive layer;
A peeling step in which the substrate on the half wavelength retardation layer side is peeled integrally with the alignment film for half wavelength retardation layer from the quarter wavelength plate to produce the optical film transfer body. Prepare.

  According to (6), the retardation layer of the 1/4 wavelength retardation layer due to the residual solvent of the adhesive layer is reduced by causing the alignment film for the 1/4 wavelength retardation layer to function as a protective layer of the 1/4 wavelength retardation layer. can do. On the 1/2 phase difference layer side, the influence of retardation drop is small, and by making the upper and lower adhesive layers, the influence of the residual solvent can be reduced. In the configuration in which the influence of retardation drop can be sufficiently reduced, and the laminate of the ½ wavelength retardation layer and the ¼ wavelength retardation layer is directly arranged on the panel surface of the image display panel. The effect of retardation drop can be effectively avoided while reducing the thickness.

(7) An optical film transfer body producing step for producing an optical film transfer body,
A bonding step according to a linearly polarizing plate, wherein the optical film transfer body is bonded to a linearly polarizing plate to produce a laminate of the optical film transfer body and the linearly polarizing plate;
A support substrate peeling step in which the support substrate of the optical film transfer member is peeled from the laminate of the optical film transfer member and the linearly polarizing plate, and the adhesive layer and the separator film are sequentially disposed,
The transfer film production process for the optical film,
An alignment film for a quarter-wave retardation layer according to a quarter-wave retardation layer on the support substrate, and the quarter-wave retardation for imparting a quarter-wave phase difference to transmitted light. A quarter wavelength phase difference layer manufacturing step of sequentially manufacturing layers and manufacturing a quarter wavelength phase difference layer side laminate;
On the base on the 1/2 wavelength phase difference layer side, the alignment film for 1/2 wavelength phase difference layer related to the 1/2 wavelength phase difference layer and the phase difference for 1/2 wavelength are given to the transmitted light A step of producing a ½ wavelength phase difference layer in which a ½ wavelength phase difference layer is sequentially produced to produce a laminate on the side of the ½ wavelength phase difference layer;
Bonding the quarter-wave retardation layer and the half-wave retardation layer together with an adhesive layer to prepare the optical film transfer body, and a bonding step according to the optical film transfer body,
The bonding process according to the linearly polarizing plate,
The substrate on the ½ wavelength retardation layer side is peeled integrally with the alignment film for ½ wavelength retardation layer from the transfer body for optical film, and bonded to the linear polarizing plate.

  According to (7), the retardation layer of the 1/4 wavelength retardation layer due to the residual solvent of the adhesive layer is reduced by causing the alignment film for the 1/4 wavelength retardation layer to function as a protective layer of the 1/4 wavelength retardation layer. can do. On the 1/2 phase difference layer side, the influence of retardation drop is small, and by making the upper and lower adhesive layers, the influence of the residual solvent can be reduced. In the configuration in which the influence of retardation drop can be sufficiently reduced, and the laminate of the ½ wavelength retardation layer and the ¼ wavelength retardation layer is directly arranged on the panel surface of the image display panel. The effect of retardation drop can be effectively avoided while reducing the thickness.

(8) An alignment film for a quarter wavelength retardation layer according to a quarter wavelength retardation layer on the support substrate, and the quarter wavelength for imparting a retardation for a quarter wavelength to transmitted light. A step of producing a quarter-wave retardation layer for producing a laminate on the quarter-wave retardation layer side by sequentially producing a retardation layer;
On the base on the 1/2 wavelength phase difference layer side, the alignment film for 1/2 wavelength phase difference layer related to the 1/2 wavelength phase difference layer and the phase difference for 1/2 wavelength are given to the transmitted light A step of producing a ½ wavelength phase difference layer in which a ½ wavelength phase difference layer is sequentially produced to produce a laminate on the side of the ½ wavelength phase difference layer;
A bonding step according to a quarter-wave plate for producing a quarter-wave plate by bonding the quarter-wave retardation layer and the half-wave retardation layer with an adhesive layer;
A peeling step of producing a transfer body for an optical film by peeling the base on the half wavelength retardation layer side from the quarter wavelength plate integrally with the alignment film for half wavelength retardation layer. .

  According to (8), the retardation layer of the 1/4 wavelength retardation layer due to the residual solvent of the adhesive layer is reduced by causing the alignment film for the 1/4 wavelength retardation layer to function as a protective layer of the 1/4 wavelength retardation layer. can do. On the 1/2 phase difference layer side, the influence of retardation drop is small, and by making the upper and lower adhesive layers, the influence of the residual solvent can be reduced. In the configuration in which the influence of retardation drop can be sufficiently reduced, and the laminate of the ½ wavelength retardation layer and the ¼ wavelength retardation layer is directly arranged on the panel surface of the image display panel. The effect of retardation drop can be effectively avoided while reducing the thickness.

(9) On the support substrate, the quarter wavelength retardation layer alignment film according to the quarter wavelength retardation layer, and the quarter wavelength for imparting a quarter wavelength retardation to the transmitted light. A step of producing a quarter-wave retardation layer for producing a laminate on the quarter-wave retardation layer side by sequentially producing a retardation layer;
On the base on the 1/2 wavelength phase difference layer side, the alignment film for 1/2 wavelength phase difference layer related to the 1/2 wavelength phase difference layer and the phase difference for 1/2 wavelength are given to the transmitted light A step of producing a ½ wavelength phase difference layer in which a ½ wavelength phase difference layer is sequentially produced to produce a laminate on the side of the ½ wavelength phase difference layer;
A bonding step of bonding the quarter-wave retardation layer and the half-wave retardation layer with an adhesive layer to produce a transfer body for an optical film,
The optical film transfer body is prepared so that the adhesion force between the half-wave retardation layer and the alignment film for the half-wave retardation layer is minimized as compared with the adhesion between other portions. To do.

  According to (9), the quarter wavelength retardation layer alignment film is allowed to function as a protective layer for the quarter wavelength retardation layer to reduce retardation drop of the quarter wavelength retardation layer due to the residual solvent of the adhesive layer. can do. On the 1/2 phase difference layer side, the influence of retardation drop is small, and by making the upper and lower adhesive layers, the influence of the residual solvent can be reduced. In the configuration in which the influence of retardation drop can be sufficiently reduced, and the laminate of the ½ wavelength retardation layer and the ¼ wavelength retardation layer is directly arranged on the panel surface of the image display panel. The effect of retardation drop can be effectively avoided while reducing the thickness.

  In the present invention, in a configuration in which a laminate of a ½ wavelength retardation layer and a ¼ wavelength retardation layer is directly arranged on the panel surface of an image display panel, the effect of retardation drop is effectively reduced while reducing the overall thickness. Can be avoided.

It is sectional drawing which shows the image display apparatus which concerns on 1st Embodiment of this invention. It is sectional drawing which shows the optical film applied to the image display apparatus of FIG. It is a figure where it uses for description of the optical film of FIG. It is sectional drawing which shows the transfer film which concerns on the optical film of FIG. It is a figure where it uses for description of the manufacturing process of the transfer film of FIG. It is a figure where it uses for description of the manufacturing process of the optical film by the transfer film of FIG. It is a figure where it uses for description of the process of the continuation of FIG. It is a figure where it uses for description of the manufacturing process of FIG. FIG. 9 is a diagram for explaining the continuation of FIG. 8.

[First Embodiment]
[Optical film and image display device]
FIG. 1 is a diagram showing an image display apparatus according to the first embodiment of the present invention. In the image display device 11, an optical film 13 is disposed on the panel surface (viewer side surface) of the image display panel 12. Here, the image display panel 12 is an organic EL panel, for example, and displays a desired color image. Note that the image display panel 12 is not limited to the organic EL panel, and various image display panels such as a liquid crystal display panel can be widely applied.

  FIG. 2 is a cross-sectional view showing the optical film 13. The optical film 13 is an optical film that suppresses reflection of extraneous light arriving at the image display panel 12 by the function of a circularly polarizing plate. For this reason, the optical film 13 is configured by laminating a linear polarizing plate 15 and a quarter-wave plate 16. The optical film 13 is peeled off the separator film to expose the pressure-sensitive adhesive layer 14 made of a pressure-sensitive adhesive that is a pressure-sensitive adhesive, and is then stuck and held on the panel surface of the image display panel 12 by the pressure-sensitive adhesive layer 14. . In addition, it may replace with a pressure sensitive adhesive and you may arrange | position the optical film 13 with another adhesive. The linear polarizing plate 15 and the quarter wavelength plate 16 are integrated with each other through the adhesive layer 17. Here, the adhesive layer 17 only needs to be able to secure a practically sufficient adhesive force. For example, although an adhesive of an ultraviolet curable resin or a thermosetting resin can be widely applied, the viewpoint of reducing the overall thickness From the viewpoint of effectively avoiding the retardation drop of the ½ wavelength retardation layer 19 caused by the adhesive layer 17, it is preferable to apply an ultraviolet curable resin, and in this case, a thickness of about 1 μm is used. Can do.

  The quarter wavelength plate 16 includes a quarter wavelength retardation layer 18 that imparts a phase difference of ¼ wavelength to transmitted light, and a ½ wavelength that imparts a phase difference of ½ wavelength to the transmitted light. It is comprised by the laminated body which bonded together the phase difference layer 19 with the contact bonding layer 20. FIG. Thereby, the optical film 13 sufficiently suppresses reflection of extraneous light in a wide wavelength band used for displaying a color image.

  The quarter wavelength plate 16 includes, from the image display panel 12 side, a quarter wavelength retardation layer alignment film 22, a quarter wavelength retardation layer 18, and an adhesive layer that are used for the production of the quarter wavelength retardation layer 18. 20, 1/2 wavelength phase difference layers 19 are sequentially provided. As a result, the quarter-wave plate 16 causes the quarter-wave retardation layer alignment film 22 to function as a protective layer, thereby reducing damage to the quarter-wave retardation layer 18.

  Further, the influence of the residual solvent on the adhesive layer 14 is reduced by the function as the protective layer of the alignment film 22 for the quarter wavelength retardation layer, and the retardation drop of the quarter wavelength retardation layer 18 due to the influence of the residual solvent is effectively performed. To avoid. That is, the optical film 13 may be peeled off from the image display panel 12 due to misalignment, mixing of bubbles, and the like, and thus reworkability is required. For this reason, although it is necessary to arrange the adhesive (adhesive layer 14) on the image display panel 12, the adhesive has a large amount of residual solvent, and the adhesive layer 14 is provided directly on the quarter-wave retardation layer 18. Then, a retardation drop occurs. However, in the case where the adhesive layer 14 is disposed via the quarter-wave retardation layer alignment film 22 as in this embodiment, the quarter-wave retardation layer alignment film 22 is also free from residual solvent. It functions as a protective layer, thereby preventing retardation drop of the quarter-wave retardation layer 18.

  On the other hand, on the ½ wavelength phase difference layer 19 side, the retardation drop due to the influence of the residual solvent amount is reduced by integrating the linear polarizing plate 15 with the adhesive layer 17 made of an ultraviolet curable resin or the like. be able to. Further, the half-wavelength retardation layer 19 has a thickness approximately twice that of the quarter-wavelength retardation layer 18, so that even if retardation drops occur, The effect is small. Thus, on the ½ wavelength phase difference layer 19 side, the entire thickness of the linear polarizing plate 15 is directly integrated with the adhesive layer 17 without providing an alignment film for ½ wavelength phase difference layer. Can be reduced.

  Accordingly, in this embodiment, in the laminated body of the ½ wavelength retardation layer and the ¼ wavelength retardation layer, the ¼ wavelength retardation layer side which is the image display panel side uses the corresponding alignment film as a protective layer. By making it function and by not providing an alignment film on the ½ wavelength phase difference layer side which is the opposite side, the influence of retardation drop is reduced while reducing the overall thickness.

  Accordingly, in the image display device 11, the ¼ wavelength phase difference layer 18, the ½ wavelength phase difference layer 19, and the linear polarizing plate 15 are sequentially arranged from the display screen side of the image display panel 12. Also, as shown in FIG. 3, the slow axes (indicated by arrows respectively) of the ½ wavelength phase difference layer 19 and the ¼ wavelength phase difference layer 18 with respect to the transmission axis of the linearly polarizing plate 15 indicated by arrows. Are arranged so as to form angles of 15 degrees and 73 degrees counterclockwise, respectively.

  The quarter-wave retardation layer alignment film 22 is formed by forming a fine line-shaped uneven shape on the surface, and is related to the quarter-wave retardation layer 18 by the alignment regulating force due to the fine line-shaped uneven shape. Align the liquid crystal material. The alignment film 22 for quarter-wave retardation layer has a ten-point average roughness (Rz) of 10 nm or more and 45 nm or less, and an average surface roughness (Ra) of 1 nm or more and 4 nm or less. . Thereby, the alignment film 22 for 1/4 wavelength phase difference layer ensures sufficient adhesion strength with the corresponding 1/4 wavelength phase difference layer 18, so that the 1/4 wavelength phase difference layer related to so-called black luminance is obtained. 18 variations can be made sufficiently small.

  In this embodiment, the quarter-wave retardation layer alignment film 22 is formed on the surface of the shaping resin layer by a shaping treatment after a shaping resin layer for forming a fine uneven shape is formed. It is formed by creating a fine lie-like uneven shape. In this embodiment, an ultraviolet curable resin is applied to the shaping resin, and an acrylic ultraviolet curable resin is used. However, the present invention is not limited to this, and various resins used for the shaping process can be widely applied. it can.

  Further, the fine uneven shape of the alignment film 22 for the quarter wavelength retardation layer is formed by a line-like uneven shape extending in one direction, and the direction extending in this one direction is the linear polarizing plate 15. It is created in a direction that forms an angle of 15 degrees counterclockwise with respect to the transmission axis.

  The quarter-wave retardation layer 18 and the half-wave retardation layer 19 are in a state in which the refractive index anisotropy is maintained by the orientation regulating force of the corresponding orientation films 22 and 23 (the orientation film 23 will be described later). It is formed of a solidified (cured) liquid crystal material. More specifically, the quarter-wave retardation layer 18 and the half-wave retardation layer 19 are formed by laminating a polymerizable liquid crystal monomer on the alignment films 22 and 23, and then raising the temperature to the phase transition point. It is produced by polymerizing a polymerizable liquid crystal monomer by irradiation to fix the alignment state of the liquid crystal. Although the ¼ wavelength retardation layer 18 and the ½ wavelength retardation layer 19 can widely apply various liquid crystal materials applicable to this type of optical film, in this embodiment, the same material is used. Applied. More specifically, for example, the compounds represented by the following chemical formulas (1) to (13) are used for the quarter-wave retardation layer 18 and the half-wave retardation layer 19.

  Although the adhesive layer 20 can widely apply various adhesives such as an ultraviolet curable resin and a thermosetting resin agent, it is an ultraviolet curable resin from the viewpoint of reducing the overall thickness and reducing retardation drops. In this case, it can be formed with a thickness of about 1 μm. In this embodiment, an ultraviolet curable resin applied to the preparation of the alignment film is applied.

  The linearly polarizing plate 15 is provided with the optical functional layer 15B after the lower surface side of the base material 15A made of a transparent film such as TAC (triacetylcellulose) is saponified. In addition, 15 A of base materials replace with this, poly (meth) methyl acrylate, poly (meth) butyl acrylate, methyl (meth) acrylate- (meth) butyl acrylate copolymer, (meth) acrylate methyl- A resin such as an acrylic resin such as a styrene copolymer, a glass such as soda glass, potash glass, lead glass, or quartz glass can be used.

  The optical functional layer 15B is a part that bears an optical function as a linearly polarizing plate, and is produced, for example, by adsorbing and orienting iodine compound molecules on a film material made of polyvinyl alcohol (PVA).

  Thus, in the optical film 13, by configuring the quarter wavelength plate 16 with a laminate in which the quarter wavelength retardation layer 18 and the half wavelength retardation layer 19 are bonded by the adhesive layer 20, respectively. The ¼ wavelength phase difference layer 18 and the ½ wavelength phase difference layer 19 created by separate processes can be used, and thereby an alignment film and a phase difference layer are sequentially laminated. In this case, it can be created by effectively avoiding shortage of adhesion and insufficient adhesion, and as a result, it can be created with high stability and reliability.

  In the optical film 13, an antireflection coating layer, a hard coating layer, an antireflection coating layer, and a hard coating layer are formed on the side surface opposite to the optical functional layer 15B of the base material 15A provided on the linear polarizing plate 15, as necessary. Various functional layers 10 such as a laminate are provided.

[Transcript]
In the optical film 13, the quarter-wave plate 16 and the linear polarizing plate 15 are integrated by the adhesive layer 17, and the transfer method is applied to a series of processes related to this integration. Thereby, in this embodiment, the substrate to be transferred is the linear polarizing plate 15, and the layers (transfer layers) used for transfer are the quarter-wave retardation layer alignment film 22 and the quarter-wave retardation layer 18. 1 is a laminate of an adhesive layer 20 and a half-wave retardation layer 19.

  FIG. 4 is a diagram showing a configuration of a transfer film 21 which is this transfer body. The transfer film 21 is formed on the support base material 25, the quarter-wave retardation layer alignment film 22, the quarter-wave retardation layer 18, the adhesive layer 20, and the half-wave retardation layers 19, 1/2. A wavelength retardation layer alignment film 23 and a substrate 24 are provided.

  Here, the support base material 25 is a base material that is detachably supported after the transfer layer is detachably supported and the transfer layer is bonded and laminated on the transfer target substrate. In this embodiment, a PET (Polyethylene terephthalate) film, which is a transparent film material, is applied. The PET film is subjected to corona treatment as necessary, whereby the adhesion force is appropriately set. The support substrate 25 may be a resinous film material made of a resin such as a polyester resin such as polybutylene terephthalate or polyethylene aphthalate, or a polyolefin resin such as polypropylene or polymethylpentene.

  When the peelability from the transfer layer is insufficient, the support base material 25 is provided with a release layer that promotes peeling on the transfer layer side. Here, the release layer can be applied with a material having relatively high adhesion to the support substrate 25 (low peelability) and low adhesion to the transfer layer (high peelability). . In this embodiment, the lowermost layer of the transfer layer is an alignment film 22 for a quarter wavelength retardation layer made of an ultraviolet curable resin. Polymer compound), fluorine-based resin, melamine resin, epoxy resin, or a mixture of these resins and other resins (acrylic resin, cellulose-based resin, polyester resin, etc.) as appropriate.

  Incidentally, when the peelability by the release layer is insufficient, a release layer may be provided between the support substrate 25 and the release layer, and this release layer may be used to supplement the peelability by the release layer. . For the release layer, a material having relatively low adhesion to the support film (high peelability) and high adhesion to the release layer (low peelability) can be applied. More specifically, in this embodiment, the release layer includes an acrylic resin, a cellulose resin, a polyester resin, a urethane resin, a vinyl chloride-vinyl acetate copolymer, or a mixture of two or more selected from the above. Alternatively, a mixture of one or more selected from the above and other resins can be applied.

  The alignment film 23 for the half-wave retardation layer is formed such that the extending direction of the line-shaped uneven shape is a direction that forms an angle of 73 degrees counterclockwise with respect to the transmission axis of the linear polarizing plate 15. Except for the configuration related to the ½ wavelength retardation layer 29 such as a point, the configuration is the same as the alignment film 22 for the ¼ wavelength retardation layer.

  The base material 24 is a base material that carries the transfer layer (in this case, the ½ wavelength retardation layer 19) so as to be peelable, and is subjected to peeling and removal as appropriate at the time of transfer or the like. In this embodiment, it is configured the same as the support base material 25. Moreover, also in the base material 24, in order to set appropriately the contact | adhesion power with the alignment film 23 for lower layer 1/2 wavelength phase difference layers, a corona process is performed as needed, and contact | adhesion power is improved.

  These support substrate 25, 1/4 wavelength retardation layer alignment film 22, 1/4 wavelength retardation layer 18, adhesive layer 20, 1/2 wavelength retardation layer 19, 1/2 wavelength retardation layer alignment The transfer film 21 made of a laminate of the film 23 and the base material 24 is between the ½ wavelength phase difference layer 19 and the ½ wavelength phase difference layer alignment film 23 indicated by reference numeral M1 among these layers. The adhesive layer 17 is set so as to have the smallest adhesion force, whereby the alignment film 23 for the ½ wavelength retardation layer is peeled off integrally with the base material 25, and the adhesive layer 17 is directly attached to the ½ wavelength retardation layer 19. It arrange | positions and it is comprised so that it can integrate with the linearly-polarizing plate 15. FIG. Subsequently, as indicated by reference numeral M2, the adhesive force between the support substrate 25 and the quarter-wave retardation layer alignment film 22 is set to be small, whereby the alignment film 22 is used as a transfer layer. It is comprised so that it can function as a protective layer including. In addition, when a long film material is pulled out from a roll, which will be described later, and processed continuously, the adhesion between the ½ wavelength phase difference layer 19 and the ½ wavelength phase difference layer alignment film 23 is reduced to other parts. By setting it to 7/8 or less as compared with the smallest adhesion force, stable and reliable processing can be executed. The adhesion between the support substrate 25 and the quarter-wave retardation layer alignment film 22 is between the half-wave retardation layer 19 and the half-wave retardation layer alignment film 23. If the adhesion strength is set to 9/10 or less compared to the smallest adhesion strength between other parts, the stable and reliable processing can be executed.

〔Manufacturing process〕
FIG. 5 is a diagram for explaining the manufacturing process of the transfer film 21. In this manufacturing process, the half-wave retardation layer alignment film 23 and the half-wave retardation layer 19 are formed on the substrate 24 (FIG. 5A). In addition, the quarter-wave retardation layer alignment film 22 and the quarter-wave retardation layer 18 are formed on the substrate 25 (FIG. 5B). In the manufacturing process, the optical characteristics of the ½ wavelength phase difference layer 19 and the ¼ wavelength phase difference layer 18 are inspected by transmitted light, respectively, and then the ½ wavelength phase difference layer 19 and ¼ wavelength are obtained by the adhesive layer 20. The phase difference layer 18 is bonded together, thereby creating the transfer film 21 (FIG. 5C).

  In the case where the ½ wavelength phase difference layer 19 and the ¼ wavelength phase difference layer 18 are individually formed and integrated as in this embodiment, the ½ wavelength phase difference layer 19, 1 / The optical characteristics of the four-wavelength retardation layer 18 can be inspected. As a result, the quality can be improved and the optical film 13 can be produced stably.

  FIG. 6 is a diagram for explaining the manufacturing process of the optical film 13 that follows. In this manufacturing process, the base material 24 is peeled off from the transfer film 21 integrally with the alignment film 23 for the half-wave retardation layer (FIG. 6A), and then the linear polarizing plate 15 is formed via the adhesive layer 17. Pasting (FIG. 6 (B)), thereby producing the optical film 13. In this embodiment, the step of peeling the base material 24 and the alignment film 23 for the ½ wavelength phase difference layer is provided in the manufacturing process of the optical film 13, the base material 24, the ½ wavelength phase difference. The transfer film 21 is provided to the manufacturing process of the optical film 13 in a form in which the alignment film 23 for the layer is peeled off, and the base film 24 and the alignment film 23 for the ½ wavelength retardation layer are formed in the manufacturing process of the transfer film 21. It may be peeled off.

  Subsequently, as shown in FIG. 7, this step is performed after the support base material 25 is peeled from the optical film 13 (FIG. 7A), and then the adhesive layer 14 and the separator film are arranged to have a desired size. The optical film 13 is produced by cutting. In the subsequent manufacturing process of the image display device 11, in the final process, the separator film is peeled to expose the adhesive layer 14, and the optical film 13 is attached to the panel surface of the image display panel 12 through the adhesive layer 14 (FIG. 7). (B)). In addition, you may perform the process which peels the support body base material 25 in the manufacturing process of an image display apparatus.

  FIG. 8 is a diagram showing the manufacturing process described above with reference to FIGS. 5 (A) and 5 (B). In FIG. 8, the structure for forming the quarter-wave retardation layer 22 and the quarter-wave retardation layer 18 on the base material 25 shown in FIG. Show.

  In this manufacturing process, the base material 24 is pulled out from the supply reel 31, coated with a coating solution of an ultraviolet curable resin with a die 32, and then dried with a drying furnace 33. Note that the coating of the coating liquid is not limited to using a die, and various methods can be applied. In this manufacturing process, the roll plate 34 is a mold for molding in which the line-shaped uneven shape related to the alignment film 23 for the half-wavelength retardation layer is formed on the peripheral side surface. In this manufacturing process, the base material 24 coated with an ultraviolet curable resin is pressed against a roll plate 34 by a pressure roller 35, and the ultraviolet curable resin is cured by irradiation with ultraviolet rays by an ultraviolet irradiation device 36 made of high-pressure mercury vapor. . Thus, in the manufacturing process, the uneven shape formed on the peripheral side surface of the roll plate 34 is transferred to the substrate 24. Thereafter, the substrate 24 is peeled off together with the ultraviolet curable resin cured from the roll plate 34 by the peeling roller 37, and a coating liquid of a liquid crystal material is applied by the die 39. Then, after drying in the drying furnace 40, the liquid crystal material is cured by irradiating ultraviolet rays from the ultraviolet irradiating device 41, and taken up on the take-up reel 42. By this series of treatments, the half-wave retardation layer alignment film 23 and the half-wave retardation layer 19 are formed on the substrate 24.

  Further, in this manufacturing process, instead of the roll plate 34, a roll plate 44 used for the production of the alignment film 22 for the quarter wavelength retardation layer is arranged, and similarly, the base material 25 is pulled out from the supply reel 31, After coating the coating solution of the ultraviolet curable resin by 32, the coating liquid is dried by the drying furnace 33, and the quarter wavelength retardation layer alignment film 22 is formed by the roll plate 44. Further, after the liquid crystal material is applied and dried, the liquid crystal material is cured and wound on the take-up reel 52, whereby the quarter-wave retardation layer alignment film 22 is formed on the substrate 25. The quarter wavelength retardation layer 18 is formed.

  FIG. 9 is a diagram for explaining the bonding process of the quarter wavelength retardation layer 18 and the half wavelength retardation layer 19 (FIG. 5C). In this manufacturing process, the laminate of the base material 24, the ½ wavelength retardation layer alignment film 23, and the ½ wavelength retardation layer 19 is drawn out from the take-up reel 42, and the ultraviolet curing as an adhesive is performed by the die 55. After the application of the conductive resin, the laminate of the substrate 25, the quarter-wave retardation layer alignment film 22 and the quarter-wave retardation layer 18 which are dried by the drying furnace 56 and pulled out from the take-up reel 52, Laminate. Thereafter, the rollers 59A and 59B are sandwiched and brought into close contact with each other, and then the ultraviolet curable resin applied by irradiating the ultraviolet rays with the ultraviolet irradiation device 57 is cured, and then wound around the take-up reel 58.

[Other Embodiments]
The specific configuration suitable for the implementation of the present invention has been described in detail above. However, the present invention can be variously combined or modified with the configuration of the above-described embodiment without departing from the spirit of the present invention. Can do.

  That is, in the above-described embodiment, the case where the ¼ wavelength phase difference alignment film and the ½ phase difference alignment film are produced by the shaping process is described. However, the present invention is not limited to this, and the light distribution film. Therefore, the present invention can be widely applied to the production of the quarter wavelength retardation film and the half retardation film.

2, 15A, 24, 25 Base material 3, 23 Alignment film for 1/2 wavelength retardation layer (alignment film)
4, 19 1/2 wavelength retardation layer 5, 22 Alignment film for 1/4 wavelength retardation layer (alignment film)
6, 18 1/4 wavelength retardation layer 7, 16 1/4 wavelength plate 11, 71 Image display device 12 Image display panel 13, 73 Optical film 14 Adhesive layer 15 Linearly polarizing plate 15B Optical functional layer 17, 20 Adhesive layer 21 Transfer film 31 Supply reel 32, 39 Die 33, 40 Drying furnace 34, 44 Roll plate 35, 37 Roller 36, 41, 57 Ultraviolet irradiation device 42, 52, 58 Take-up reel 55 Die 56 Drying furnace 59A, 59B Roller

Claims (4)

An optical film transfer body producing step for producing an optical film transfer body;
A bonding step according to a linearly polarizing plate, wherein the optical film transfer body is bonded to a linearly polarizing plate to produce a laminate of the optical film transfer body and the linearly polarizing plate;
A support substrate peeling step in which the support substrate of the optical film transfer member is peeled from the laminate of the optical film transfer member and the linearly polarizing plate, and the adhesive layer and the separator film are sequentially disposed,
The transfer film production process for the optical film,
An alignment film for a quarter-wave retardation layer according to a quarter-wave retardation layer on the support substrate, and the quarter-wave retardation for imparting a quarter-wave phase difference to transmitted light. A quarter wavelength phase difference layer manufacturing step of sequentially manufacturing layers and manufacturing a quarter wavelength phase difference layer side laminate;
On the base on the 1/2 wavelength phase difference layer side, the alignment film for 1/2 wavelength phase difference layer related to the 1/2 wavelength phase difference layer and the phase difference for 1/2 wavelength are given to the transmitted light A step of producing a ½ wavelength phase difference layer in which a ½ wavelength phase difference layer is sequentially produced to produce a laminate on the side of the ½ wavelength phase difference layer;
A bonding step according to a quarter-wave plate for producing a quarter-wave plate by bonding the quarter-wave retardation layer and the half-wave retardation layer with an adhesive layer;
A peeling step in which the substrate on the half wavelength retardation layer side is peeled integrally with the alignment film for half wavelength retardation layer from the quarter wavelength plate to produce the optical film transfer body. A method for producing an optical film. An optical film transfer body producing step for producing an optical film transfer body;
A bonding step according to a linearly polarizing plate, wherein the optical film transfer body is bonded to a linearly polarizing plate to produce a laminate of the optical film transfer body and the linearly polarizing plate;
A support substrate peeling step in which the support substrate of the optical film transfer member is peeled from the laminate of the optical film transfer member and the linearly polarizing plate, and the adhesive layer and the separator film are sequentially disposed,
The transfer film production process for the optical film,
An alignment film for a quarter-wave retardation layer according to a quarter-wave retardation layer on the support substrate, and the quarter-wave retardation for imparting a quarter-wave phase difference to transmitted light. A quarter wavelength phase difference layer manufacturing step of sequentially manufacturing layers and manufacturing a quarter wavelength phase difference layer side laminate;
On the base on the 1/2 wavelength phase difference layer side, the alignment film for 1/2 wavelength phase difference layer related to the 1/2 wavelength phase difference layer and the phase difference for 1/2 wavelength are given to the transmitted light A step of producing a ½ wavelength phase difference layer in which a ½ wavelength phase difference layer is sequentially produced to produce a laminate on the side of the ½ wavelength phase difference layer;
Bonding the quarter-wave retardation layer and the half-wave retardation layer together with an adhesive layer to prepare the optical film transfer body, and a bonding step according to the optical film transfer body,
The bonding process according to the linearly polarizing plate,
A method for producing an optical film, wherein the substrate on the half-wavelength phase difference layer side is peeled integrally with the alignment film for the half-wavelength phase difference layer from the transfer body for the optical film and bonded to the linearly polarizing plate. . An alignment film for a quarter-wave retardation layer related to a quarter-wave retardation layer on a support substrate, and the quarter-wave retardation layer for imparting a quarter-wave phase difference to transmitted light. Are sequentially manufactured to produce a quarter-wave retardation layer-side laminate.
On the base on the 1/2 wavelength phase difference layer side, the alignment film for 1/2 wavelength phase difference layer related to the 1/2 wavelength phase difference layer and the phase difference for 1/2 wavelength are given to the transmitted light A step of producing a ½ wavelength phase difference layer in which a ½ wavelength phase difference layer is sequentially produced to produce a laminate on the side of the ½ wavelength phase difference layer;
A bonding step according to a quarter-wave plate for producing a quarter-wave plate by bonding the quarter-wave retardation layer and the half-wave retardation layer with an adhesive layer;
A peeling step of producing a transfer body for an optical film by peeling the base on the half wavelength retardation layer side from the quarter wavelength plate integrally with the alignment film for half wavelength retardation layer. ,
The production process of the ¼ wavelength retardation layer includes:
Following the adhesion between the half-wave retardation layer and the alignment film for half-wave retardation layer, the adhesion between the support substrate and the alignment film for quarter-wave retardation layer The manufacturing method of the transfer body for optical films which produces the laminated body by the side of 1/4 wavelength phase difference layer so that may become small. An alignment film for a quarter-wave retardation layer related to a quarter-wave retardation layer on a support substrate, and the quarter-wave retardation layer for imparting a quarter-wave phase difference to transmitted light. Are sequentially manufactured to produce a quarter-wave retardation layer-side laminate.
On the base on the 1/2 wavelength phase difference layer side, the alignment film for 1/2 wavelength phase difference layer related to the 1/2 wavelength phase difference layer and the phase difference for 1/2 wavelength are given to the transmitted light A step of producing a ½ wavelength phase difference layer in which a ½ wavelength phase difference layer is sequentially produced to produce a laminate on the side of the ½ wavelength phase difference layer;
A bonding step of bonding the quarter-wave retardation layer and the half-wave retardation layer with an adhesive layer to produce a transfer body for an optical film,
The adhesion between the half-wave retardation layer and the alignment film for the half-wave retardation layer is the smallest compared to the adhesion between other parts, and then the support substrate and 1 The method for producing a transfer member for an optical film, wherein the transfer member for an optical film is prepared so that the adhesion between the alignment film for a / 4 wavelength retardation layer is reduced.

Images