JP2014071380A - Transfer body for optical film, optical film, image display device, and production method of optical film - Google Patents

Abstract

An optical film that reduces the reflection of extraneous light by controlling the plane of polarization is provided that does not impair the flexibility of an object to be placed.
A linear polarizing plate 103 comprising a transparent film substrate 132 and an optical functional layer 131, a quarter-wave plate retardation layer 101, an adhesive layer 121b, and a half-wave plate retardation layer 102 are provided. The optical film 1 is formed by laminating a circularly polarizing plate 104, and the quarter-wave plate retardation layer 101 or the half-wave plate retardation layer 102 has a plurality of linear shapes extending in a certain direction. It is an optical film consisting of a liquid crystal layer with irregularities formed on the surface.
[Selection] Figure 1

Description

  The present invention relates to an optical film that is disposed on, for example, an image display panel and reduces reflection of extraneous light by controlling a polarization plane.

  Conventionally, with respect to an image display panel or the like, a method has been proposed in which an optical film is disposed on the exit surface of the image display panel and the reflection of extraneous light is reduced by controlling the polarization plane with the optical film. This optical film is composed of a linearly polarizing plate and a circularly polarizing plate, and converts external light directed to the panel surface of the image display panel into linearly polarized light by the linearly polarizing plate and then converts it to circularly polarized light by the subsequent circularly polarizing plate. 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, the reflected light is converted from the circularly polarizing plate to linearly polarized light in the direction shielded by the linearly polarizing plate, and then shielded by the subsequent linearly polarizing plate. Is significantly suppressed.

  With regard to this optical film, Patent Document 1 and the like describe a method of configuring this optical film with negative dispersion characteristics by configuring a circularly polarizing plate by combining a 1/2 retardation plate and a 1/4 retardation plate. Proposed. In the case of this method, an optical film can be formed with negative dispersion characteristics in a wide wavelength band used for displaying a color image.

  By the way, in an image display apparatus using an organic EL panel, a flexible sheet shape is being provided in recent years. In such an image display device having a flexible sheet shape, for example, an image can be displayed in a state where the entire image is bent outward or bent in the opposite direction. It is considered that the application field of image display devices can be expanded.

  However, when displaying an image in a state where the entire image is bent outward or bent in the opposite direction, it is necessary to significantly reduce the reflection of external light as compared with the conventional case. Thereby, in the image display apparatus by the sheet | seat shape which has flexibility, it is thought that it is necessary to avoid the influence by external light effectively by arrange | positioning the above-mentioned optical film. In particular, in an organic EL panel, the reflection of extraneous light by the internal electrodes is remarkable, so that it is desirable to apply this type of optical film.

  However, when a conventional optical film is simply applied to a flexible sheet-shaped image display panel, there is a problem that the flexibility of the image display panel is significantly impaired.

JP-A-10-68816

  This invention is made | formed in view of such a condition, It aims at keeping the flexibility of an arrangement | positioning target object with respect to the optical film which reduces reflection of external light by control of a polarization plane.

The present inventor has intensively studied to solve the above-mentioned problems, and has arrived at the idea of reducing the overall thickness by creating an optical film by applying a transfer technique, thereby completing the present invention. It came to.
(1) a substrate made of a transparent film;
A liquid crystal layer that is formed on a substrate made of the transparent film and that has a plurality of line-shaped irregularities extending in a certain direction on the surface to impart a phase difference to transmitted light. For transfer.
According to (1), since the retardation layer can be formed only by the liquid crystal layer, it is thinner than a known optical film having an alignment layer together with the liquid crystal layer, and is advantageous in not impairing the flexibility of the object to be arranged. An optical film transfer body for an optical film can be provided.
(2) a substrate made of a transparent film;
An optical functional layer of a linearly polarizing plate that functions as a linearly polarizing plate;
The optical functional layer of the circularly polarizing plate that functions as a circularly polarizing plate is laminated,
The optical functional layer of the circularly polarizing plate includes the liquid crystal layer of the optical film transfer body according to any one of claims 1 to 3 on the optical functional layer of the linearly polarizing plate. .
According to (2), since the optical functional layer is a retardation layer formed only of a liquid crystal layer, the optical functional layer is thinner than an optical film having a known retardation layer having an alignment layer together with the liquid crystal layer as an optical functional layer. An optical film advantageous in that the flexibility of the object is not impaired can be provided.
(3) The liquid crystal layer is an optical film of a retardation layer for a half-wave plate that imparts a retardation of a half wavelength to transmitted light.
According to (3), since the retardation layer for a half-wave plate can be formed only by a liquid crystal layer, an optical film including a known retardation layer for a half-wave plate having an alignment layer together with the liquid crystal layer It is possible to provide an optical film that is thinner than that and advantageous in that the flexibility of the object to be placed is not impaired.
(4) The liquid crystal layer is an optical film of a retardation layer for a quarter wavelength plate that imparts a retardation for a quarter wavelength to transmitted light.
According to (4), since the retardation layer for a quarter wavelength plate can be formed only by the liquid crystal layer, the configuration includes a known retardation layer for a quarter wavelength plate having an alignment layer together with the liquid crystal layer. It is possible to provide an optical film that is advantageous in that it is thin and does not impair the flexibility of the object to be arranged.
(5) a laminate configured by laminating a plurality of optical films;
An optical functional layer of a circularly polarizing plate serving as a circularly polarizing plate transferred to the laminate,
With
The optical functional layer of the circularly polarizing plate is an optical film of a liquid crystal layer in which a plurality of line-shaped irregularities extending in a certain direction are formed on the surface and a phase difference is imparted to transmitted light.
According to (5), since the retardation layer of the circularly polarizing plate contained in the laminate can be formed only by the liquid crystal layer, it is thinner than the configuration including a known retardation layer having an alignment layer together with the liquid crystal layer, It is possible to provide an optical film that is advantageous in that the flexibility of the object to be placed is not impaired.
(6) The image display apparatus which has arrange | positioned the optical film as described in any one of said (2) to said (5).
According to (6), it is possible to provide an image display device in which the flexibility of the display screen is not impaired by disposing the thinned optical film.
(7) In the method of manufacturing an optical film that reduces reflection of extraneous light by controlling the polarization plane,
An application process for directly applying a liquid crystal material to a transparent substrate;
A drying step of drying the liquid crystal material applied in the application step;
The surface of the liquid crystal material dried in the drying step is subjected to a shaping treatment, and the crystalline material is solidified in a state of being oriented by the orientation regulating force by the shaping mold according to the shaping treatment to form a retardation layer. A retardation layer forming step of forming an optical film.
According to (7), since the phase difference layer can be formed by aligning the surface of the liquid crystal material, the optical film is manufactured with fewer steps than the known optical film manufacturing method for forming the alignment layer together with the liquid crystal layer. Can do. For this reason, the manufacturing process of an optical film which is thinner than a well-known optical film and is advantageous in not sacrificing the flexibility of an arrangement | positioning target object can be simplified, manufacturing cost can be reduced, and production efficiency can be improved.
(8) The quarter-wave plate retardation layer for imparting a phase difference of ¼ wavelength to the transmitted light or the ½ wavelength for imparting a phase difference of ½ wavelength to the transmitted light It is a manufacturing method of the optical film of the phase difference layer for plates.
According to (8), the manufacturing process of the optical film including the retardation layer for a quarter-wave plate and the retardation layer for a half-wave plate can be simplified, the manufacturing cost can be reduced, and the production efficiency can be increased. .

  With respect to the optical film that reduces the reflection of extraneous light by controlling the polarization plane, the flexibility of the object to be arranged can be maintained.

It is a figure which shows the image display apparatus by which the optical film and optical film of one Embodiment of this invention are arrange | positioned. It is a figure for demonstrating the slow layer axis | shaft of the phase difference layer for 1/4 wavelength plates shown in FIG. 1, the phase difference layer for 1/2 wavelength plates, and a linearly-polarizing plate. It is a figure which shows the structure of the transfer film which is a transfer body of one Embodiment of this invention. It is a figure for demonstrating the manufacturing process of the optical film of one Embodiment of this invention. It is a figure for demonstrating the manufacturing process of the transfer film of one Embodiment of this invention. It is the figure which illustrated the antireflection film to which the transfer film of one embodiment of the present invention is applied. It is a figure for demonstrating other embodiment of this invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[Optical film and image display device]
FIG. 1 is a diagram showing an optical film 1 of the present embodiment and an image display device 100 on which the optical film 1 is arranged. The optical film 1 is disposed on the display surface (image display panel surface) of the image display device 100. The image display panel 5 is an organic EL panel having a flexible sheet shape.

  The optical film 1 is an optical film that suppresses reflection of extraneous light arriving at the image display panel 5 by controlling the polarization plane, and is configured by laminating a linearly polarizing plate 103 and a circularly polarizing plate 104. The linearly polarizing plate 103 and the circularly polarizing plate 104 are bonded together by an adhesive layer 121a. Further, the circularly polarizing plate 104 is configured by bonding a quarter-wave plate retardation layer 101 and a half-wave plate retardation layer 102 with an adhesive layer 121b.

  Furthermore, an adhesive layer 121c is provided on the surface (back surface) of the circularly polarizing plate 104 that is in contact with the image display panel 5. The separator film (not shown) is peeled from the adhesive layer 121 c to expose the adhesive layer 121 c and contact the surface of the image display panel 5, whereby the optical film 1 is attached to the image display panel 5. The pressure-sensitive adhesive layers 121a, 121b, and 121c in this embodiment are layers formed by applying a pressure sensitive adhesive (PSA).

The quarter-wave plate retardation layer 101 is a portion of the circularly polarizing plate 104 that functions as a quarter-phase plate that imparts a quarter-wave phase difference to transmitted light. The half-wave plate retardation layer 102 is a part that functions as a half-phase plate that imparts a half-wave phase difference to transmitted light.
In the present embodiment, a quarter-wave plate retardation layer 101, a half-wave plate retardation layer 102, and a linear polarizing plate 103 are sequentially arranged from the display screen side of the image display panel 5.
The circularly polarizing plate 104 ensures positive dispersion characteristics in a wide wavelength band used for displaying a color image, and the optical film 1 sufficiently suppresses reflection of extraneous light in a wide wavelength band.

  FIG. 2 is a diagram for explaining the slow axis of the quarter-wave plate retardation layer 101, the half-wave plate retardation layer 102, and the linear polarizing plate 103 shown in FIG. As shown in FIG. 2, the slow axes of the quarter-wave plate retardation layer 101 and the half-wave plate retardation layer 102 with respect to the transmission axis of the linearly polarizing plate 103 indicated by arrows (respectively indicated by arrows). Are arranged so as to form angles of 15 degrees and 73 degrees counterclockwise, respectively.

  More specifically, the in-plane retardation (Re) of the quarter-wave plate retardation layer 101 is 110 nm or more and 150 nm or less, and the in-plane retardation (Re) of the half-wave plate retardation layer 102. ) Is not less than 235 nm and not more than 285 nm. With such a retardation plate 101 for a quarter wavelength plate and a retardation layer 102 for a half wavelength plate, the optical film 1 has a visible light wavelength range (380 to 780 nm) incident from the linear polarizing plate 103 side. The transmitted light is irradiated with circularly polarized light having an ellipticity of 0.8 or more and emitted.

  The circularly polarizing plate 104 includes a quarter-wave plate retardation layer 101 and a half-wave plate retardation layer 102 provided in this order from the image display panel 5 side. The quarter-wave plate retardation layer 101 and the half-wave plate retardation layer 102 are formed of a liquid crystal material that is solidified (cured) while maintaining refractive index anisotropy. Fine line-shaped irregularities are formed on the surfaces of the quarter-wave plate retardation layer 101 and the half-wave plate retardation layer 102 by a shaping process. Hereinafter, the surface having the irregularities of the quarter-wave plate retardation layer 101 is referred to as a shaping surface 101a, and the surface having the irregularities of the half-wave plate retardation layer 102 is referred to as a shaping surface 102a.

  The fine irregularities of the shaping surface 101a and the shaping surface 102a are formed by linear (line) irregularities extending in one direction. The line-shaped unevenness of the shaping surface 101 a is created so that the line forms an angle of 73 degrees counterclockwise with respect to the absorption axis (slow axis) of the linear polarizing plate 103. The line-shaped unevenness of the shaping surface 102 a is created so that the line forms an angle of 15 degrees counterclockwise with respect to the absorption axis (slow axis) of the linear polarizing plate 103.

  In the linear polarizing plate 103, the optical functional layer 131 is disposed after the lower surface side of the base material 132 made of a transparent film such as TAC (triacetyl cellulose) is saponified. The base material 132 is replaced with methyl poly (meth) acrylate, poly (meth) butyl acrylate, methyl (meth) acrylate-butyl (meth) acrylate copolymer, methyl (meth) acrylate- 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 131 is a part that bears an optical function as a linear polarizing plate, and is produced, for example, by adsorbing and orienting iodine compound molecules on a film material of polyvinyl alcohol (PVA).
In the circularly polarizing plate 104 described above, the thickness of the quarter-wave plate retardation layer 101 is about 1 μm. The thickness of the half-wave plate retardation layer 102 is about 2 μm, and the thickness of the adhesive layer 121 c is 15 μm or less. For this reason, in this embodiment, the thickness of the circularly polarizing plate 104 can be 18 μm or less. In the linear polarizing plate 103, the thickness of the base material 132 is about 30 μm, the thickness of the optical functional layer 131 is 20 μm or less, and the thickness of the adhesive layer 121a is 15 μm or less. For this reason, in this embodiment, the thickness of the linearly polarizing plate 103 can be set to 65 μm or less.

  From the above, in this embodiment, the optical film 1 having an overall thickness of 85 μm or less can be provided. Such an optical film 1 can ensure sufficient flexibility.

[Transfer]
The circularly polarizing plate 104 shown in FIG. 1 is integrated with the linearly polarizing plate 103 through the adhesive layer 121a to form the optical film 1. A transfer method is applied to the process of integrating the circularly polarizing plate 104 and the linearly polarizing plate 103.
In this transfer method, 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 bonded to the substrate (transferred substrate) 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 laminating and then peeling off and removing the support.

In this embodiment, the layer configuration related to the circularly polarizing plate 104 is laminated on the linearly polarizing plate 103 by a transfer method. At this time, the substrate to be transferred is the linearly polarizing plate 103, and the layer used for transfer (transfer layer) has a shaping surface 102a on the quarter-wave plate retardation layer 101 having the shaping surface 101a. The circularly polarizing plate 104 to which the wave plate retardation layer 102 is transferred is obtained.
FIG. 3 is a diagram illustrating a configuration of a transfer film 3 which is a transfer body according to the present embodiment. The transfer film 3 includes a quarter-wave plate retardation layer 101 provided on a support substrate 301 and a half-wave plate retardation layer 102 provided on another substrate (not shown). It is constituted by adhering with the adhesive layer 121b and further adhering the separator film 302 with the adhesive layer 121a.

  The adhesive layer 121a is a layer for adhering the separator film 302 onto the retardation layer 102 for a half-wave plate. The adhesive layer 121b is a layer for adhering the transfer layer and the substrate to be transferred. As the material of the adhesive layers 121a and 121b, a material having high adhesiveness is applied to both according to the material of the transfer layer and the material of the substrate to be transferred. The adhesive layers 121a and 121b of the present embodiment include, for example, acetylcellulose (cellulose acetate), nitrocellulose (cellulose nitrate or nitrified cotton), cellulose (fiberglass) resin such as cellulose acetate propionate, poly ( Acrylic resins such as methyl (meth) acrylate, poly (meth) butyl acrylate, (meth) methyl acrylate- (meth) butyl acrylate copolymer, (meth) methyl acrylate-styrene copolymer, urethane resin, Materials such as polyester resin, vinyl chloride-vinyl acetate copolymer, ionomer, natural or synthetic rubber are used. The thickness of the adhesive layer 121a is about 1 to 30 μm. Moreover, the thickness of the adhesion layer 121b is about 0.1-50 micrometers.

  The molding surface 101a is created by using a molding die (roll plate) in which fine line-shaped irregularities are formed on the peripheral side surface and providing irregularities on the surface of the retardation layer 101 for quarter-wave plates. Is done. Further, the shaping surface 102a is created by using a roll plate having fine line-shaped irregularities formed on the peripheral side surface and providing irregularities on the surface of the retardation layer 102 for half-wave plates. The detailed manufacturing method of the retardation layer 101 for quarter wavelength plates and the retardation layer 102 for half wavelength plates will be described later.

  The separator film 302 is a release sheet that covers the surface of the pressure-sensitive adhesive layer 121a so that it can be released. The separator film 302 is provided in order to prevent the adhesive layer 121a from being exposed and causing unnecessary adhesion to unnecessary articles, and is peeled off and removed immediately before transfer.

The support substrate 301 detachably supports a layer (transfer layer) to be transferred, and after the transfer layer is bonded and laminated on the transfer target substrate, the substrate is appropriately peeled off and removed as needed. It is. In the present embodiment, for example, a PET (Polyethylene terephthalate) film, which is a transparent film material, is applied to the support substrate 301. By applying a transparent film material to the support substrate 301, the optical properties of the transfer film 3 can be inspected.
The PET film is subjected to corona treatment in order to adjust the adhesion between the release film and a release layer described later. The support base material 301 may have a sheet shape as a whole. The support substrate 301 is not limited to a PET film, but is a resinous film made of a resin such as a polyester resin such as polyethylene terephthalate, polybutylene terephthalate, or polyethylene aphthalate, or a polyolefin resin such as polypropylene or polymethylpentene. Material may be applied. In addition, the thickness of the support base material 301 is 20-100 micrometers. If the peelability from the transfer layer is insufficient, a release layer that promotes peeling may be provided on the transfer layer side.

  As the release layer, a material having relatively high adhesion to the support substrate 301 (low releasability) and low adhesion to the transfer layer (high releasability) can be applied. In the present embodiment, as the release layer, for example, a silicon resin (organosilicon-based polymer compound), a fluorine-based resin, a melamine resin, an epoxy resin, or other appropriate resin (acrylic resin, cellulose-based resin, A mixture with a polyester resin or the like) is used.

  In this embodiment, instead of providing a release layer made of melamine resin on a corona-treated PET film, a PET film that has not been surface-treated at all may be applied to a support substrate to omit the release layer. . Alternatively, a release layer may be omitted by applying a TAC film without a so-called permeation layer called a nonsol to the support substrate. In this way, the configuration can be simplified.

  Incidentally, when the peelability by the release layer is insufficient, a release layer may be provided between the support substrate 301 and the release layer, and the release layer may supplement the peelability by the release layer. . As 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, 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, or a combination of the above. A mixture of one or more selected from the above and other resins is used. The thickness of the release layer is usually about 1 to 10 μm. Further, the release layer may be provided on the support substrate 301 or may be provided on the release layer.

[Manufacturing process of optical film]
FIG. 4 is a view for explaining a manufacturing process of the optical film 1 and shows a process of integrating the linearly polarizing plate 103 and the transfer film 3 shown in FIG. In this step, the base material 132 that has been subjected to the saponification treatment related to the linearly polarizing plate 103 is provided by the supply reel 403. An optical functional layer 131 is provided by the supply reel 404. Then, the transfer film 3 is provided by the supply reel 406.

The transfer film 3 is pulled out from the supply reel 406, and the separator film 302 is peeled off by the peeling roller 407. The pressure-sensitive adhesive layer 121a is exposed by the separation of the separator film 302. The separated separator film 302 is taken up by a take-up reel 405.
Further, the base material 132 is pulled out from the supply reel 403, and the film member related to the optical function layer 131 is pulled out from the supply reel 404. The transfer film 3 from which the separator film 302 has been peeled is laminated with the film member and the base material 132 related to the optical function layer 131 and pressed by the pressure rollers 402A and 402B. The pressed transfer film 3 (separator film 302 peeling), the film member, and the base material 132 are integrated.

Subsequently, the support base material 301 is peeled off by the peeling roller 408 from the transfer film 3 (separator film 302 peeling) integrated with the film member and the base material 132. The peeled support substrate 301 is taken up by the take-up reel 40. Through the above steps, the optical film 1 shown in FIG. 1 is manufactured.
An adhesive that will later become the adhesive layer 121c is applied to the surface of the optical film 1 from which the support substrate 301 has been peeled off (not shown). After the separator film 303 supplied from the supply reel 411 is attached on the adhesive, the optical film 1 is pressed by the pressure rollers 409A and 409B and taken up by the take-up reel 401.

[Transfer manufacturing process]
Next, the manufacturing method of the transfer film 3 shown in FIGS. In the following description, the half-wave plate retardation layer 102 and the quarter-wave plate retardation layer 101 are described as being manufactured on the same line. However, the half-wave plate retardation layer 102 and the quarter-wave plate retardation layer 101 may be manufactured on different lines.
FIGS. 5A and 5B are diagrams for explaining the manufacturing process of the transfer film 3. FIG. 5A shows a manufacturing process of the quarter-wave plate retardation layer 101, and FIG. 5B shows a manufacturing process of the half-wave plate retardation layer 102. As shown in FIG. 5A, in the present embodiment, first, the support base material 301 is pulled out from the supply reel 501. In step A, an ultraviolet curable liquid crystal material 521 is applied to the surface of the support substrate 301.

In this embodiment, the liquid crystal material 521 is applied by applying a so-called gravure printing technique. According to this method, the plate cylinder 503 is immersed in the liquid crystal material and rotated to apply the liquid crystal material to the contact surface with the support base material 301. The impression cylinder 502 comes into contact with the back surface of the surface of the support substrate 301 that contacts the plate cylinder 503, and the amount of the liquid crystal material 521 on the surface of the support substrate 301 is adjusted.
The support base material 301 to which the liquid crystal material 521 is applied is sent to the process B. In step B, the support base material 301 and the liquid crystal material 521 are sent to the drying furnace 505 and dried.

In the above process, as the liquid crystal material 521, for example, a nematic liquid crystal, a smectic liquid crystal, specifically, an A plate forming material manufactured by Merck is considered. Moreover, in this embodiment, the conveyance speed of the support base material 301 and the liquid crystal material 521 heading from the process A to the process B is 0.5 m / min to 40 m / min, the drying temperature in the process B is 40 degrees to 150 degrees, The drying time is 10 seconds to 180 seconds. The support substrate 301 is not damaged even when heated to 150 degrees.
By doing in this way, in this embodiment, the liquid crystal material 521 can be made into a hardness suitable for a subsequent shaping process.

The support base material 301 and the liquid crystal material 521 that have exited the drying furnace 505 are sent to Step C. In Step C, the liquid crystal material 521 comes into contact with the peripheral surface of the roll plate 507 while being pressed from the back surface of the support base material 301 by a nip roll (not shown). The roll plate 507 is a mold for molding in which fine irregularities for forming the molding surface 101a are formed on the peripheral side surface (rubbed in a certain direction).
When the surface of the dried liquid crystal material 521 is brought into contact with the peripheral surface of the roll plate 507, fine irregularities are formed on the surface of the liquid crystal material 521. In Step C, the liquid crystal material 521 is irradiated with ultraviolet (UV) light while the unevenness is formed. The liquid crystal material 521 is cured (solidified) by irradiation with ultraviolet rays to form the quarter-wave plate retardation layer 101, and the surface thereof becomes the shaping surface 101a.

In Step C, UV irradiation is performed while adjusting the temperature so that the liquid crystal material 521 has a temperature equal to or higher than the phase transition temperature. By adjusting the temperature, the liquid crystal material 521 is aligned on the roll plate 507 and cured in that state. The temperature adjustment is performed, for example, so that the liquid crystal material 521 has a temperature of 40 degrees to 150 degrees.
Through the above steps, the quarter-wave plate retardation layer 101 is directly formed on the support substrate 301. The support substrate 301 and the quarter-wave plate retardation layer 101 are taken up by a take-up reel 508.

  Next, a manufacturing process of the half-wave plate retardation layer 102 shown in FIG. 5B will be described. In the present embodiment, in the process D, the support base material 511 taken up by the take-up reel 508 is drawn out. A liquid crystal material 522 is applied on the drawn support base material 511 by a plate cylinder 503 and an impression cylinder 502. Note that the application of the liquid crystal material 522 is performed in the same manner as the application of the liquid crystal material 521 in Step A.

The support base material 511 to which the liquid crystal material 522 is applied is sent to the process E. In step E, the support substrate 511 and the liquid crystal material 522 (hereinafter also referred to as the liquid crystal material 522 and the like) are sent to the drying furnace 505 and dried.
In the above process, as the liquid crystal material 522, for example, a nematic liquid crystal, a smectic liquid crystal, specifically, an A plate forming material manufactured by Merck is considered. In the present embodiment, the transport speed of the liquid crystal material 522 and the like from the process D to the process E is 0.5 m / min to 40 m / min, the drying temperature in the process E is 40 to 150 degrees, and the drying time is 10 seconds. ˜180 seconds. The support substrate 301 is not damaged even when heated to 150 degrees.
By doing in this way, in this embodiment, the liquid crystal material 522 can be made into a hardness suitable for the subsequent shaping process.

The liquid crystal material 522 and the like exiting the drying furnace 505 are sent to the process F. In step F, the roll plate 507 is replaced with a roll plate 517 whose peripheral surface is rubbed in a direction different from that of the roll plate 507. The roll plate 507 is replaced when the quarter-wave plate retardation layer 101 and the half-wave plate retardation layer 102 are manufactured using the same line.
In Step F, the liquid crystal material 522 and the like come into contact with the peripheral surface of the roll plate 517 while being pressed from the back by a nip roll (not shown). The roll plate 517 is a mold for molding in which fine irregularities for forming the molding surface 102a are formed on the peripheral side surface (rubbed in a certain direction).
When the surface of the dried liquid crystal material 522 comes into contact with the peripheral surface of the roll plate 517, fine irregularities are formed on the surface of the liquid crystal material 522. In the process F, the liquid crystal material 522 is irradiated with ultraviolet rays while the unevenness is formed. The liquid crystal material 522 is cured (solidified) by ultraviolet irradiation to form the half-wave plate retardation layer 102, and the surface thereof becomes the shaping surface 102a.

In Step C, UV irradiation is performed while adjusting the temperature so that the liquid crystal material 521 has a temperature equal to or higher than the phase transition temperature. By adjusting the temperature, the liquid crystal material 521 is aligned on the roll plate 507 and cured in that state. The temperature adjustment is performed, for example, so that the liquid crystal material 521 has a temperature of 40 degrees to 150 degrees.
The half-wave plate retardation layer 102 is directly formed on the support substrate 301 through the above steps. The support substrate 301 and the half-wave plate retardation layer 102 are taken up by a take-up reel 508.

When the peripheral surface of the roll plate 517 and the surface of the liquid crystal material 522 are in contact with each other, the shaping surface 102 a is formed on the surface of the liquid crystal material 522. Further, the liquid crystal material 522 is cured by receiving ultraviolet (UV) irradiation in the process F. By the formation and curing of the shaping surface 102a, the liquid crystal material 522 becomes the quarter-wave plate retardation layer 101.
In the present embodiment, in step F, as in step C, UV irradiation is performed while adjusting the temperature so that the liquid crystal material 522 has a temperature equal to or higher than the phase transition temperature. The temperature adjustment at this time is performed, for example, so that the liquid crystal material 522 has a temperature of 40 degrees to 150 degrees.

  The retardation layer 102 for half-wave plates manufactured in the process of FIG. 5B passes through the adhesive layer 121b to the retardation layer 101 for quarter-wave plates manufactured in the process of FIG. And pasted together. After the quarter-wave plate retardation layer 101 is bonded, the support substrate 511 is peeled off. Through the above steps, the circularly polarizing plate 104 is formed. In the next step (not shown), an adhesive layer 121 a is formed on the circularly polarizing plate 104. A separator film 302 is disposed on the adhesive layer 121a, and the transfer film 3 shown in FIG. 3 is completed.

  According to the present embodiment described above, the quarter-wave plate retardation layer 101 and the half-wave plate retardation layer 102 without the alignment layer can be formed by aligning the liquid crystal layer. For this reason, the configuration can be simplified, and the overall shape can be reduced to ensure sufficient flexibility.

[Application example]
6A and 6B are diagrams illustrating an antireflection film to which the transfer film 3 of the present embodiment described above is applied. The antireflection film shown in FIG. 6A is provided on the surface of the support substrate 301 of the transfer film (separator film 302, adhesive layer 121a peeling) shown in FIG. 3 where the circularly polarizing plate 104 is not provided. A pressure-sensitive adhesive (PSA) 601, TAC (triacetyl cellulose) 602, polyvinyl alcohol (PVA) 603, TAC 604, and hard coat material (HC) 605 are laminated.

In the antireflection film of FIG. 6A, the pressure-sensitive adhesive 601 may be an ultraviolet curable adhesive. The TAC 602 may be an acrylic resin film or a Zero Retention TAC (Z-TAC).
In addition, the antireflection film shown in FIG. 6A can be configured not to include the TAC 602.
The antireflection film shown in FIG. 6B is the same as the transfer film (separator film 302, adhesive layer 121a peeled off) shown in FIG. 3 except for the pressure sensitive adhesive 601, TAC602, polyvinyl alcohol 603, TAC604, and hard coat material 605. It is constituted by being transferred to the laminate. The antireflection film shown in FIG. 6B is advantageous in reducing the thickness of the film than the antireflection film shown in FIG.

[effect]
According to the manufacturing method of the optical film of the present embodiment described above, the quarter-wave plate retardation layer 101 and the half-wave plate retardation layer 102 are formed by directly shaping the surface of the resin material. can do.
For this reason, this embodiment is more advantageous for reducing the thickness, and can provide an optical film and an optical film transfer body that do not impair the flexibility of the object to be arranged. Moreover, this embodiment can provide the image display apparatus by which such an optical film is arrange | positioned.

Furthermore, according to the manufacturing method of the optical film of this embodiment described above, for example, a phase difference phase such as a phase difference layer for a quarter wavelength plate, a phase difference layer for a half wavelength plate, An optical film can be manufactured in fewer steps than a known technique in which an alignment layer is formed by laminating a liquid crystal layer and an alignment layer.
For this reason, this embodiment can raise the productivity of the optical film and the transfer body for optical films, and can also reduce the cost concerning manufacture.

[Experimental example]
The inventors of the present invention verified the effect of the antireflection film of this embodiment by the following experiment. The experimental conditions will be specifically described below.
In the experiment, a half-wave plate retardation layer was formed on the TAC substrate. The half-wave plate retardation layer was formed by the following procedure.
A Miyabar liquid crystal (Merck RMM899) was applied to one side of the TAC original fabric, dried by oven drying at 80 ° C. for 1 minute, and cooled to room temperature. Furthermore, it is laminated with a hand roller on a ballad plate whose surface is rubbed at 45 ° (preheated to a surface temperature of 65 ° C. to 67 ° C.), irradiated with ultraviolet rays from the TAC original fabric side, and the liquid crystal layer is peeled from the TAC original fabric. .

  The liquid crystal layer prepared by the above experiment functioned as a retardation layer for a half-wave plate. Moreover, in the said experiment, even if it changed the TAC base material into PET, the same retardation layer for 1/2 wavelength plates was able to be obtained. Furthermore, by separating the liquid crystal layer from PET, a retardation layer for a half-wave plate, which was a single transfer product, could be obtained.

[Other Embodiments]
The specific configuration suitable for the implementation of the present invention has been described in detail above. However, the present invention is not limited to the scope of the present invention, and various combinations of the above-described embodiments, and further the configuration of the above-described embodiments. Can be variously changed.
That is, in the above-described embodiment, the circularly polarizing plate 104 in which the quarter-wave plate retardation layer 101 and the half-wave plate retardation layer 102 are bonded together by the adhesive layer 121b is described. However, the present invention is not limited to this, and the quarter-wave plate retardation layer 101 and the half-wave plate retardation layer 102 can each be used as a single optical film.

Further, the quarter-wave plate retardation layer 101 and the half-wave plate retardation layer 102 of the present embodiment are not limited to optical films formed on a support substrate. The quarter-wave plate retardation layer 101 and the half-wave plate retardation layer 102 of the present embodiment are transferred products that are transferred to a laminated product of another optical film and then peeled off from the support substrate. Can also be configured.
FIG. 7A is a diagram showing a quarter-wave plate retardation layer 101 configured as a single optical film, and FIG. 7B is a diagram showing a half-wave plate retardation layer 102. is there. FIG. 7 (c) shows a single quarter-wave plate retardation layer 101 configured as a transfer product, and FIG. 7 (d) shows a single product for a half-wave plate configured as a transfer product. The phase difference layer 102 is shown.

  In the above-described embodiment, an adhesive layer is provided on the transfer layer side, and the linearly polarizing plate and the transfer layer are integrated by this adhesive layer. However, the present invention is not limited to this, and the adhesive layer may be provided on the linearly polarizing plate side.

Further, in the above-described embodiment, the liquid crystal materials to be the quarter-wave plate retardation layer 101 and the half-wave plate retardation layer 102 are applied by a gravure printing technique. However, the present invention is not limited to this, and a liquid crystal material may be applied to a substrate using a die coater, a micro gravure, or a comma coater.
In the above-described embodiment, the ultraviolet curable resin is applied to the retardation layer 101 for quarter-wave plate and the retardation layer 102 for half-wave plate. However, the present invention is not limited to this, and thermosetting is performed. The quarter-wave plate retardation layer 101 and the half-wave plate retardation layer 102 can also be manufactured using a resin.

In the above-described embodiment, the case where the quarter-wave plate retardation layer 101 and the half-wave plate retardation layer 102 are subjected to a shaping process using a roll plate is described, but the present invention is not limited thereto. The present invention can also be widely applied to the case where the forming process is performed using a flat plate.
Further, in the above-described embodiment, the surface of the quarter-wave plate retardation layer 101 and the half-wave plate retardation layer 102 is used as an alignment film by the shaping process, but the present invention is not limited to this, and the light The present invention can be widely applied to the case where an alignment film is formed by an alignment method. In this case, only one of the quarter-wave plate retardation layer 101 and the half-wave plate retardation layer 102 may be formed of a photo-alignment film, or both may be formed of a photo-alignment film. May be.

Moreover, in the above-described embodiment, the case where the adhesive layer 121c and the separator film 303 are arranged by continuous processing of the roll material has been described, but the present invention is not limited thereto, and after separately cutting the optical film into a sheet shape, It may be arranged on the transfer film 3.
In the above-described embodiment, the case where the optical film is arranged on the image display panel having a flexible sheet shape is described. can do. Furthermore, it can be widely applied when it is arranged on various members to prevent reflection.

DESCRIPTION OF SYMBOLS 1 Optical film 3 Transfer film 5 Image display panel 100 Image display apparatus 101 1/4 wavelength plate phase difference layer 101a, 102a Molding surface 102 1/2 wavelength plate phase difference layer 103 Linearly polarizing plate 104 Circularly polarizing plate 121a, 121b, 121c Adhesive layer 131 Optical functional layer 132 Base material 301 Support base material 302, 303 Separator film

Claims (8)

A substrate made of a transparent film;
A transfer body for an optical film, comprising: a liquid crystal layer formed on a substrate made of the transparent film, wherein a plurality of line-shaped irregularities extending in a certain direction are formed on a surface to impart a retardation to transmitted light. A substrate made of a transparent film;
An optical functional layer of a linearly polarizing plate that functions as a linearly polarizing plate;
The optical functional layer of the circularly polarizing plate that functions as a circularly polarizing plate is laminated,
The optical functional layer of the circularly polarizing plate includes the liquid crystal layer of the optical film transfer body according to claim 1. The optical film according to claim 2, wherein the liquid crystal layer is a retardation layer for a ½ wavelength plate that imparts a retardation of ½ wavelength to transmitted light. The optical film according to claim 2, wherein the liquid crystal layer is a quarter-wave plate retardation layer that imparts a phase difference of ¼ wavelength to transmitted light. A laminate formed by laminating a plurality of optical films;
An optical functional layer of a circularly polarizing plate serving as a circularly polarizing plate transferred to the laminate,
With
The optical functional layer of the circularly polarizing plate is a liquid crystal layer in which a plurality of line-shaped irregularities extending in a certain direction are formed on the surface, and a phase difference is imparted to transmitted light. An image display device comprising the optical film according to any one of claims 2 to 5. In the method of manufacturing an optical film that reduces the reflection of extraneous light by controlling the polarization plane,
An application process for directly applying a liquid crystal material to a transparent substrate;
A drying step of drying the liquid crystal material applied in the application step;
The surface of the liquid crystal material dried in the drying step is subjected to a shaping treatment, and the crystalline material is solidified in a state of being oriented by the orientation regulating force by the shaping mold according to the shaping treatment to form a retardation layer. A retardation layer forming step of forming an optical film. A phase difference layer for a quarter-wave plate in which the retardation layer imparts a phase difference of ¼ wavelength to transmitted light, or a position for a half-wave plate in which a phase difference of ½ wavelength is imparted to transmitted light It is a phase difference layer, The manufacturing method of the optical film of Claim 7.

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