Method for manufacturing optical film pieces and method for cutting optical film

Abstract

To provide optical film pieces having desired shapes with good yield.SOLUTION: A method for manufacturing an optical film piece 2 comprises: preparing an optical film body 1 rectangular or square in a plan view; and irradiating the optical film body 1 with a laser beam to cut the optical film body 1, thereby providing a plurality of optical film pieces 2. The major axes 2b of the optical film pieces 2 to be cut are arranged roughly in parallel with the first side of the optical film body 1, and the sum total of the major axes 2b of the optical film pieces 2 to be cut on a line 1b along the first side of the optical film body 1 is longer than the length of the first side of the optical film body 1.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing an optical film piece and a method for cutting an optical film. [Background technology]

[0002] Image display devices, such as liquid crystal display devices and electroluminescence (EL) display devices (e.g., organic EL display devices), are rapidly becoming popular. In image display devices, optical components such as retardation components and polarizing components are generally used to realize image display and improve the performance of the image display (see, for example, Patent Document 1).

[0003] In recent years, new applications for image display devices have been developed. For example, goggles with displays (VR goggles) for realizing virtual reality (VR) have begun to be commercialized. As the applications of image display devices expand, optical films including the optical components described above are desired to have shapes suited to the applications. For example, there is a demand for the production of optical film pieces having desired shapes. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2021-103286 Summary of the Invention [Problem to be solved by the invention]

[0005] However, depending on the shape, the yield of manufacturing the optical film pieces may be significantly reduced.

[0006] In view of the above, a main object of the present invention is to provide optical film pieces having a desired shape with a high yield. [Means for solving the problem]

[0007] 1. A method for manufacturing an optical film piece according to an embodiment of the present invention includes preparing an optical film body that is rectangular or square in plan view, and irradiating the optical film body with laser light to cut the optical film body to obtain a plurality of optical film pieces, wherein the long axes of the optical film pieces to be cut are arranged approximately parallel to a first side of the optical film body, and the sum of the long axes of the optical film pieces to be cut that exist on a line along the first side of the optical film body is longer than the length of the first side of the optical film body. 2. The manufacturing method described in 1 above includes placing the prepared optical film body on a holding plate, and the holding plate may have a through groove formed therein that corresponds to the planned cutting line of the optical film body and that allows the product produced by the laser irradiation to be sucked in. 3. In the manufacturing method described in 2 above, the planned cutting line of the prepared optical film body may be positioned so as to overlap the through groove of the holding plate in a plan view. 4. In the manufacturing method described in 2 or 3 above, the width of the through groove may be 0.1 mm or more and 3 mm or less. 5. In the manufacturing method according to any one of 2 to 4 above, the width of the through groove may be 1 to 30 times the diameter of the irradiated laser light. 6. In the manufacturing method according to any one of 2 to 5 above, the optical film body may include a sacrificial member disposed in direct contact with the holding plate. 7. In the manufacturing method according to any one of the above 1 to 6, the distance between adjacent planned cutting lines in the optical film body may be 3 mm or less. 8. In the manufacturing method according to any one of the above 1 to 7, the interval between adjacent planned cutting lines in the optical film body may be 30 times or less the diameter of the irradiated laser beam. 9. In the manufacturing method according to any one of the above 1 to 8, the distance between adjacent planned cutting lines in the optical film body may be 0.3 mm or more. 10. In the manufacturing method according to any one of the above 1 to 9, the interval between adjacent planned cutting lines in the optical film body may be three times or more the diameter of the irradiated laser beam. 11. In the manufacturing method described in any one of 1 to 10 above, the optical film piece may have at least one of a cutout portion in which the outer periphery is partially cut out in a planar view and a protrusion portion in which the outer periphery is partially protruding in a planar view.

[0008] 12. Another embodiment of a method for cutting an optical film according to the present invention includes preparing an optical film body that is rectangular or square in plan view, and irradiating the optical film body with laser light to cut the optical film body to obtain a plurality of optical film pieces, wherein the long axes of the optical film pieces to be cut are arranged approximately parallel to a first side of the optical film body, and the sum of the long axes of the optical film pieces to be cut that exist on a line along the first side of the optical film body is longer than the length of the first side of the optical film body. [Effects of the Invention]

[0009] According to the embodiment of the present invention, optical film pieces having desired shapes can be provided with a high yield. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a top view of an optical film body according to one embodiment of the present invention. [Figure 2A] 2 is a top view of an example of a holding plate on which the optical film body shown in FIG. 1 is placed. FIG. [Figure 2B] 2B is a cross-sectional view of the holding plate shown in FIG. 2A. [Figure 3] FIG. 1 is a schematic diagram showing a general configuration of an example of a display system for VR goggles. [Figure 4] FIG. 2 is a schematic cross-sectional view showing an example of the details of an optical film. [Figure 5] FIG. 1 is a schematic perspective view showing an example of a multilayer structure included in a reflective polarizing film. [Figure 6] FIG. 2 is a top view of an optical film body of a comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments. In order to clarify the description, the drawings may schematically show the width, thickness, shape, etc. of each part compared to the embodiments, but these are merely examples and do not limit the interpretation of the present invention. Furthermore, in the drawings, the same or equivalent elements are given the same reference numerals, and redundant explanations may be omitted.

[0012] (Definition of terms and symbols) The definitions of terms and symbols used in this specification are as follows. (1) Refractive index (nx, ny, nz) "nx" is the refractive index in the direction in which the in-plane refractive index is greatest (i.e., the slow axis direction), "ny" is the refractive index in the direction perpendicular to the slow axis in the plane (i.e., the fast axis direction), and "nz" is the refractive index in the thickness direction. (2) In-plane phase difference (Re) "Re(λ)" is the in-plane retardation measured with light of wavelength λ nm at 23°C. For example, "Re(550)" is the in-plane retardation measured with light of wavelength 550 nm at 23°C. Re(λ) is calculated by the formula: Re(λ)=(nx-ny)×d, where d (nm) is the thickness of the layer (film). (3) Retardation in the thickness direction (Rth) "Rth(λ)" is the retardation in the thickness direction measured with light of wavelength λ nm at 23°C. For example, "Rth(550)" is the retardation in the thickness direction measured with light of wavelength 550 nm at 23°C. Rth(λ) is calculated by the formula: Rth(λ) = (nx - nz) × d, where d (nm) is the thickness of the layer (film). (4) Nz coefficient The Nz coefficient is calculated by Nz=Rth / Re. (5)Angle When angles are referred to herein, the angles include both clockwise and counterclockwise angles relative to a reference direction, so for example, "45°" means ±45°.

[0013] An optical film cutting method according to an embodiment of the present invention includes a step of irradiating a prepared sheet-like optical film body with laser light to cut the optical film body. By cutting the optical film body, for example, multiple optical film pieces having a desired shape can be obtained. Furthermore, using a laser can significantly improve the degree of freedom in the shape of the obtained optical film pieces compared to, for example, cutting with a blade. Note that, in this specification, the term "optical film" may be used as a general term for sheet-like optical film bodies, optical film pieces, and precursors for obtaining sheet-like optical film bodies (e.g., long optical film bodies). Here, "long" refers to an elongated shape in which the length is sufficiently longer than the width, for example, a elongated shape in which the length is 10 times or more, preferably 20 times or more, the width.

[0014] The planar shape of the sheet-like optical film body can be rectangular or square. FIG. 1 is a top view of an optical film body according to one embodiment of the present invention. The planar shape of the optical film body 1 is rectangular. The dashed line 1a in FIG. 1 indicates a planned cutting line. By irradiating the planned cutting line 1a with laser light to cut the optical film body 1, multiple optical film pieces 2 can be obtained. In the illustrated example, the optical film pieces 2 are substantially elliptical with a major axis, but are not limited thereto. For example, the optical film pieces 2 may be substantially circular or rectangular with rounded corners.

[0015] The major axis of the optical film piece 2 to be cut is arranged substantially parallel to the direction of the first side (e.g., long side) of the optical film body 1. Here, the major axis is the distance between the two most distant points on the planned cutting line or the outer periphery. "Substantially parallel" encompasses a case where the angle is 0°±5°, and is preferably 0°±3°, more preferably 0°±1°, and even more preferably 0°±0.5°. The first side corresponds, for example, to the width direction of the long optical film body.

[0016] In the illustrated example, six optical film pieces 2 to be cut are present on a line 1b along the first side of the optical film body 1. The six optical film pieces 2 to be cut are arranged at positions overlapping the line 1b. The sum of the major axes 2b of the optical film pieces 2 to be cut that are present on the line 1b is longer than the length of the first side (line 1b) of the optical film body 1. By arranging the optical film pieces 2 to be cut in a zigzag pattern in this way, the optical film pieces 2 can be obtained with a good yield.

[0017] In the optical film body 1, the distance between adjacent planned cutting lines 1a is preferably 3 mm or less, more preferably 2.5 mm or less, and even more preferably 2 mm or less. The distance between adjacent planned cutting lines 1a is, for example, 30 times or less, more preferably 25 times or less, and even more preferably 20 times or less the diameter of the irradiated laser light. On the other hand, the distance between adjacent planned cutting lines 1a is, for example, 0.2 mm or more, preferably 0.3 mm or more, and even more preferably 0.5 mm or more. The distance between adjacent planned cutting lines 1a is, for example, 2 times or more, preferably 3 times or more, and even more preferably 5 times or more the diameter of the irradiated laser light. Setting the distance in this manner can ensure the spacing between adjacent through grooves in the holding plate described below, and more accurately achieve the desired shape in the resulting optical film piece 2. Furthermore, adhesion of foreign matter (e.g., products that may be generated by laser irradiation) to the optical film piece 2 obtained by cutting can be prevented. The foreign matter is thought to be mainly products generated during cutting along adjacent planned cutting lines. The interval between adjacent planned cutting lines means the minimum distance between adjacent planned cutting lines.

[0018] The optical film piece 2 obtained by cutting has cutout portions 2a, 2a formed by partially cutting out the outer periphery in plan view. The cutout portions 2a can function, for example, as positioning portions when laminating to another member. In the illustrated example, the optical film piece has cutout portions formed therein, but this is not limiting. For example, protrusions may be formed by partially protruding the outer periphery in plan view.

[0019] Any appropriate laser can be used for irradiation as long as it can cut the optical film body 1. Preferably, a laser that emits light with a wavelength at least in the range of 8.9 μm to 10.5 μm is used. Specific examples include gas lasers such as carbon dioxide lasers (CO2 lasers), solid-state lasers, and semiconductor lasers. Any appropriate conditions for irradiating the laser light can be adopted depending on the laser used, for example. When a carbon dioxide laser is used, the frequency is, for example, 1 kHz to 100 kHz. The average power is, for example, 2 W to 200 W. The moving speed is, for example, 100 mm / sec to 1000 mm / sec.

[0020] The diameter of the laser light irradiated onto the optical film body 1 is, for example, 10 μm to 300 μm, and preferably 50 μm to 100 μm.

[0021] During laser irradiation, the optical film body 1 is typically placed on a holding plate. Fig. 2A is a top view of an example of a holding plate for placing the optical film body shown in Fig. 1, and Fig. 2B is a BB cross-sectional view of the holding plate shown in Fig. 2A. The holding plate 3 has a placement surface 3a that is a substantially horizontal plane. A large number of through holes 3b are formed in the holding plate 3, and the optical film body 1 placed on the placement surface 3a can be held on the holding plate 3 by sucking it through the through holes 3b. The diameter of the through holes 3b is, for example, 0.1 mm to 1.2 mm.

[0022] A through groove 3c is formed in the holding plate 3. The through groove 3c is formed corresponding to the planned cutting line 1a of the optical film body 1 to be placed. By forming such a through groove 3c, products that may be generated by laser irradiation (e.g., smoke, burnt residue) can be sucked from the side opposite to the laser-irradiated surface of the optical film body 1. As shown in the figure, it is preferable that one through groove 3c is formed for one optical film piece 2. From the viewpoint of efficiently removing products that may be generated by laser irradiation, it is preferable that adjacent through grooves 3c do not communicate with each other. However, some of the through grooves 3c may communicate with some of the adjacent through grooves 3c. The optical film body 1 is preferably positioned so that its planned cutting line 1a overlaps with the through groove 3c of the holding plate 3 in a planar view. This arrangement allows for efficient removal of products that may be generated by laser irradiation, and can reduce the amount of foreign matter adhering to the resulting optical film piece 2, for example. This is particularly useful when the optical film piece 2 has a cutout and / or a protrusion, as in the illustrated example. Specifically, since foreign matter tends to adhere to the cutout portion and / or protrusion, it is preferable that the products that may be generated by laser irradiation can be efficiently removed.

[0023] The width of the through groove 3c can be set to any appropriate value. The width of the through groove 3c can be set depending on, for example, the diameter of the irradiated laser light, the shape of the optical film piece, etc. The width of the through groove 3c is, for example, 0.1 mm or more and 3 mm or less. The width of the through groove 3c is, for example, 1 time or more and 30 times or less the diameter of the irradiated laser light.

[0024] A component (e.g., a retardation component and / or a polarizing component) that may be included in the optical film body 1 may have an optical axis. For example, depending on the state of the optical axis of a component that may be included in the optical film body 1, the position of the planned cutting line 1a (optical film piece 2) may be finely adjusted. Specifically, the angle formed by the direction of the major axis 2b of the optical film piece 2 with a line 1b along the direction of the first side (e.g., the long side) or a line 1c along the direction of the second side (e.g., the short side) may be finely adjusted. Even in such a case, the optical film body 1 is preferably positioned so that the planned cutting line 1a overlaps with the through groove 3c of the holding plate 3 in a planar view.

[0025] The optical film may have an optical axis. For example, the optical film may include a retardation member and may have a slow axis and a fast axis. Also, for example, the optical film may include a polarizing member and may have an absorption axis and / or a reflection axis. The optical film may be used in any appropriate image display device. The optical film may be used in, for example, VR goggles. In VR goggles, the direction of the optical axis (e.g., reflection axis) of the optical film can be controlled with extremely high precision. Therefore, the above-mentioned fine adjustment may be necessary depending on the state of the optical film body to be cut.

[0026] FIG. 3 is a schematic diagram showing the overall configuration of an example of a display system for VR goggles, illustrating the arrangement and shape of each component of the display system. The display system 10 includes a display element 12, a reflective polarizing element 14, a first lens unit 16, a half mirror 18, a first λ / 4 element 20, a second λ / 4 element 22, and a second lens unit 24. The reflective polarizing element 14 is disposed in front of the display surface 12a of the display element 12 and can reflect light emitted from the display element 12. The first lens unit 16 is disposed on the optical path between the display element 12 and the reflective polarizing element 14, and the half mirror 18 is disposed between the display element 12 and the first lens unit 16. The first λ / 4 element 20 is disposed on the optical path between the display element 12 and the half mirror 18, and the second λ / 4 element 22 is disposed on the optical path between the half mirror 18 and the reflective polarizing element 14.

[0027] The display element 12 is, for example, a liquid crystal display or an organic EL display, and has a display surface 12a for displaying an image. The light emitted from the display surface 12a passes through, for example, a polarizing member that may be included in the display element 12, and is converted into a first linearly polarized light.

[0028] The first λ / 4 member 20 can convert the first linearly polarized light incident on the first λ / 4 member 20 into first circularly polarized light. The first λ / 4 member 20 may be provided integrally with the display element 12.

[0029] The half mirror 18 transmits the light emitted from the display element 12 and reflects the light reflected by the reflective polarizing member 14 back toward the reflective polarizing member 14. The half mirror 18 is provided integrally with the first lens portion 16.

[0030] The second λ / 4 member 22 can transmit light reflected by the reflective polarizing member 14 and the half mirror 18 through the reflective polarizing member 14. The second λ / 4 member 22 may be provided integrally with the first lens portion 16.

[0031] The first circularly polarized light output from the first λ / 4 element 20 passes through the half mirror 18 and the first lens unit 16, and is converted into the second linearly polarized light by the second λ / 4 element 22. The second linearly polarized light output from the second λ / 4 element 22 is reflected toward the half mirror 18 without passing through the reflective polarizing element 14. At this time, the polarization direction of the second linearly polarized light incident on the reflective polarizing element 14 is the same as the reflection axis of the reflective polarizing element 14. Therefore, the second linearly polarized light incident on the reflective polarizing element 14 is reflected by the reflective polarizing element 14.

[0032] The second linearly polarized light reflected by the reflective polarizing element 14 is converted into second circularly polarized light by the second λ / 4 element 22, and the second circularly polarized light emitted from the second λ / 4 element 22 passes through the first lens unit 16 and is reflected by the half mirror 18. The second circularly polarized light reflected by the half mirror 18 passes through the first lens unit 16 and is converted into third linearly polarized light by the second λ / 4 element 22. The third linearly polarized light is transmitted through the reflective polarizing element 14. At this time, the polarization direction of the third linearly polarized light incident on the reflective polarizing element 14 is the same as the transmission axis of the reflective polarizing element 14. Therefore, the third linearly polarized light incident on the reflective polarizing element 14 is transmitted through the reflective polarizing element 14.

[0033] The light transmitted through the reflective polarizing member 14 passes through the second lens portion 24 and enters the eye 26 of the user.

[0034] The absorption axis of the polarizing member included in the display element 12 and the reflection axis of the reflective polarizing member 14 may be disposed approximately parallel to each other or approximately perpendicular to each other. The angle formed between the absorption axis of the polarizing member included in the display element 12 and the slow axis of the first λ / 4 member 20 is, for example, 40° to 50°, or may be 42° to 48°, or may be approximately 45°. The angle formed between the absorption axis of the polarizing member included in the display element 12 and the slow axis of the second λ / 4 member 22 is, for example, 40° to 50°, or may be 42° to 48°, or may be approximately 45°.

[0035] The in-plane retardation Re(550) of the first λ / 4 component 20 is, for example, 100 nm to 190 nm, or alternatively, 110 nm to 180 nm, 130 nm to 160 nm, or 135 nm to 155 nm. The first λ / 4 component 20 preferably exhibits inverse dispersion wavelength characteristics in which the retardation value increases according to the wavelength of the measurement light. The Re(450) / Re(550) of the first λ / 4 component 20 may be, for example, 0.75 or more and less than 1, or 0.8 or more and 0.95 or less.

[0036] The in-plane retardation Re(550) of the second λ / 4 component 22 is, for example, 100 nm to 190 nm, or alternatively, 110 nm to 180 nm, 130 nm to 160 nm, or 135 nm to 155 nm. The second λ / 4 component 22 preferably exhibits inverse dispersion wavelength characteristics in which the retardation value increases according to the wavelength of the measurement light. The Re(450) / Re(550) of the second λ / 4 component 22 may be, for example, 0.75 or more and less than 1, or 0.8 or more and 0.95 or less.

[0037] The optical film may include, for example, components included in the display system. Specifically, the optical film may include a retardation component such as a λ / 4 component. The optical film may also include a polarizing component such as a reflective polarizing component or an absorptive polarizing component. The optical film may also include other components such as a protective component and an adhesive layer for integrating adjacent components. The thickness of the optical film may vary depending on the type and number of components included, but is, for example, 50 μm to 400 μm. The optical film applied to the display system may have a shape corresponding to the shape of the first lens portion or the second lens portion. For example, it may be designed to have a shape such as a substantially elliptical or substantially circular shape. In this case, the optical film may be provided integrally with the first lens portion or the second lens portion.

[0038] FIG. 4 is a schematic cross-sectional view showing an example of the details of an optical film. The optical film piece 2 (optical film body 1) includes a reflective polarizing element 14 and an adhesive layer (e.g., a pressure-sensitive adhesive layer) that can be disposed between the reflective polarizing element 14 and the second lens portion 24. The optical film 2 further includes an absorbing polarizing element 28 that can be disposed between the reflective polarizing element 14 and the second lens portion 24, for example, to improve visibility. The absorbing polarizing element 28 is laminated in front of the reflective polarizing element 14 via an adhesive layer (e.g., a pressure-sensitive adhesive layer) 42. The absorbing polarizing element 28 includes at least an absorbing polarizing film. As shown in FIG. 4, when the absorbing polarizing element 28 does not include any other components (e.g., a protective layer) other than the absorbing polarizing film, the absorbing polarizing element 28 can correspond to the absorbing polarizing film. The absorbing polarizing film can be disposed adjacent to the reflective polarizing element 14. The reflection axis of the reflective polarizing element 14 and the absorption axis of the absorptive polarizing film included in the absorptive polarizing element 28 can be arranged substantially parallel to each other, and the transmission axis of the reflective polarizing element 14 and the transmission axis of the absorptive polarizing film included in the absorptive polarizing element 28 can be arranged substantially parallel to each other. By laminating the reflective polarizing element 14 and the absorptive polarizing element 28 via an adhesive layer, the reflective polarizing element 14 and the absorptive polarizing element 28 are fixed together, preventing misalignment of the reflection axis and the absorption axis (transmission axis and transmission axis). Furthermore, adverse effects due to an air layer that may form between the reflective polarizing element 14 and the absorptive polarizing element 28 can be suppressed. In this specification, "adjacent" includes not only being directly adjacent to each other but also being adjacent to each other via an adhesive layer.

[0039] The optical film 2 further includes a protective member 31 that can be disposed behind the reflective polarizing member 14. The protective member 31 is laminated to the reflective polarizing member 14 via an adhesive layer (for example, a pressure-sensitive adhesive layer) 41.

[0040] As shown in FIG. 4, the optical film 2 may further include a third λ / 4 member 30 that can be disposed between the absorptive polarizing member 28 and the second lens section 24. The third λ / 4 member 30 is laminated to the absorptive polarizing member 28 via an adhesive layer (e.g., a pressure-sensitive adhesive layer) 43. The angle between the absorption axis of the absorptive polarizing member 28 and the slow axis of the third λ / 4 member 30 is, for example, 40° to 50°, or may be 42° to 48°, or approximately 45°. By providing such a member, for example, reflection of external light from the second lens section 24 side can be prevented. The in-plane retardation Re(550) of the third λ / 4 member 30 is, for example, 100 nm to 190 nm, or may be 110 nm to 180 nm, 130 nm to 160 nm, or 135 nm to 155 nm. The third λ / 4 member 30 preferably exhibits inverse dispersion wavelength characteristics in which the retardation value increases according to the wavelength of the measurement light. The Re(450) / Re(550) of the third λ / 4 member is, for example, not less than 0.75 and less than 1, and may be not less than 0.8 and not more than 0.95.

[0041] In the illustrated example, the optical film 2 includes a surface protection film 51 releasably bonded to the protective member 31. The surface protection film 51 may be peeled off before the optical film 2 is used (e.g., before being laminated on the second lens portion 24) or during the manufacturing process of the final product (e.g., VR goggles), or may be directly mounted on the final product. The optical film 2 includes a sacrificial member 52 disposed on the outermost side. During the laser irradiation, if the optical film body 1 is disposed so that the sacrificial member 52 is in direct contact with the placement surface of the holding plate, suction marks due to suction may be generated on the sacrificial member 52. In the illustrated example, the optical film 2 includes an adhesive layer (e.g., a pressure-sensitive adhesive layer) 44 for integrating the optical film 2 with an adherend (e.g., the second lens portion 24), and the sacrificial member 52 is bonded to the surface of the adhesive layer 44. The sacrificial member 52 can function as a release liner. For example, the adhesive layer 44 can be protected by the sacrificial member 52.

[0042] The above λ / 4 member preferably exhibits a refractive index characteristic showing a relationship of nx > ny ≧ nz. Here, "ny = nz" includes not only the case where ny and nz are exactly equal but also the case where they are substantially equal. Therefore, within a range that does not impair the effects of the present invention, ny < nz may occur. The Nz coefficient of the λ / 4 member is preferably 0.9 to 3, more preferably 0.9 to 2.5, still more preferably 0.9 to 1.5, and particularly preferably 0.9 to 1.3.

[0043] The λ / 4 member can be, for example, a stretched film of a resin film or an orientation solidified layer of a liquid crystal compound.

[0044] Examples of the resin contained in the resin film include polycarbonate resins, polyester carbonate resins, polyester resins, polyvinyl acetal resins, polyarylate resins, cyclic olefin resins, cellulose resins, polyvinyl alcohol resins, polyamide resins, polyimide resins, polyether resins, polystyrene resins, acrylic resins, etc. These resins may be used alone or in combination. Examples of the combination method include blending and copolymerization. When the λ / 4 member exhibits an inverse dispersion wavelength characteristic, a resin film containing a polycarbonate resin or a polyester carbonate resin (hereinafter sometimes simply referred to as a polycarbonate resin) can be preferably used.

[0045] Any suitable polycarbonate-based resin can be used as the polycarbonate-based resin. For example, the polycarbonate-based resin contains structural units derived from a fluorene-based dihydroxy compound, structural units derived from an isosorbide-based dihydroxy compound, and structural units derived from at least one dihydroxy compound selected from the group consisting of alicyclic diols, alicyclic dimethanols, di-, tri-, or polyethylene glycols, and alkylene glycols or spiroglycols. Preferably, the polycarbonate-based resin contains structural units derived from a fluorene-based dihydroxy compound, structural units derived from an isosorbide-based dihydroxy compound, structural units derived from an alicyclic dimethanol, and / or structural units derived from di-, tri-, or polyethylene glycol; more preferably, it contains structural units derived from a fluorene-based dihydroxy compound, structural units derived from an isosorbide-based dihydroxy compound, and structural units derived from di-, tri-, or polyethylene glycol. The polycarbonate-based resin may contain structural units derived from other dihydroxy compounds as needed. Details of polycarbonate-based resins suitable for use in λ / 4 components and methods for forming λ / 4 components are described, for example, in JP 2014-10291 A, JP 2014-26266 A, JP 2015-212816 A, JP 2015-212817 A, and JP 2015-212818 A, and the descriptions in these publications are incorporated herein by reference.

[0046] The thickness of the λ / 4 member made of a stretched resin film is, for example, 10 μm to 100 μm, preferably 10 μm to 70 μm, and more preferably 20 μm to 60 μm.

[0047] The above-mentioned liquid crystal compound alignment solidified layer is a layer in which the liquid crystal compound is aligned in a predetermined direction within the layer and the alignment state is fixed. The term "alignment solidified layer" encompasses an alignment solidified layer obtained by solidifying a liquid crystal monomer, as described below. In a λ / 4 component, rod-shaped liquid crystal compounds are typically aligned in the slow axis direction of the λ / 4 component (homogeneous alignment). Examples of rod-shaped liquid crystal compounds include liquid crystal polymers and liquid crystal monomers. The liquid crystal compound is preferably polymerizable. If the liquid crystal compound is polymerizable, the alignment state of the liquid crystal compound can be fixed by aligning the liquid crystal compound and then polymerizing it.

[0048] The alignment and solidification layer of the liquid crystal compound (liquid crystal alignment and solidification layer) can be formed by performing an alignment treatment on the surface of a predetermined substrate, applying a coating liquid containing a liquid crystal compound to the surface to align the liquid crystal compound in a direction corresponding to the alignment treatment, and fixing the alignment state. Any appropriate alignment treatment can be used as the alignment treatment. Specific examples include mechanical alignment treatment, physical alignment treatment, and chemical alignment treatment. Specific examples of mechanical alignment treatment include rubbing treatment and stretching treatment. Specific examples of physical alignment treatment include magnetic field alignment treatment and electric field alignment treatment. Specific examples of chemical alignment treatment include oblique vapor deposition and photoalignment treatment. Any appropriate treatment conditions can be used for the various alignment treatments depending on the purpose.

[0049] The alignment of liquid crystal compounds is achieved by treating them at a temperature at which they exhibit a liquid crystal phase depending on the type of liquid crystal compound. By performing such temperature treatment, the liquid crystal compounds assume a liquid crystal state and are aligned in accordance with the alignment treatment direction on the substrate surface.

[0050] In one embodiment, the alignment state is fixed by cooling the liquid crystal compound aligned as described above. When the liquid crystal compound is polymerizable or crosslinkable, the alignment state is fixed by subjecting the liquid crystal compound aligned as described above to a polymerization treatment or crosslinking treatment.

[0051] Any suitable liquid crystal polymer and / or liquid crystal monomer can be used as the liquid crystal compound. The liquid crystal polymer and the liquid crystal monomer can be used alone or in combination. Specific examples of liquid crystal compounds and methods for producing a liquid crystal alignment solidified layer are described in, for example, JP 2006-163343 A, JP 2006-178389 A, and WO 2018 / 123551 A. The descriptions in these publications are incorporated herein by reference.

[0052] The thickness of the second λ / 4 member formed of the liquid crystal alignment solidified layer is, for example, 1 μm to 10 μm, preferably 1 μm to 8 μm, more preferably 1 μm to 6 μm, and even more preferably 1 μm to 4 μm.

[0053] The reflective polarizing element transmits polarized light parallel to its transmission axis (typically, linearly polarized light) while maintaining its polarization state, and can reflect light in other polarization states. The reflective polarizing element is typically made of a film (sometimes referred to as a reflective polarizing film) having a multilayer structure. In this case, the thickness of the reflective polarizing element is, for example, 10 μm to 150 μm, preferably 20 μm to 100 μm, and more preferably 30 μm to 60 μm.

[0054] FIG. 5 is a schematic perspective view showing an example of a multilayer structure included in a reflective polarizing film. The multilayer structure 14a has alternating birefringent layers A and layers B that are substantially not birefringent. The total number of layers constituting the multilayer structure may be 50 to 1000. For example, the refractive index nx in the x-axis direction of layer A is larger than the refractive index ny in the y-axis direction, and the refractive index nx in the x-axis direction and the refractive index ny in the y-axis direction of layer B are substantially the same, and the refractive index difference between layer A and layer B is large in the x-axis direction and substantially zero in the y-axis direction. As a result, the x-axis direction can be the reflection axis, and the y-axis direction can be the transmission axis. The refractive index difference between layer A and layer B in the x-axis direction is preferably 0.2 to 0.3.

[0055] The A layer is typically made of a material that exhibits birefringence upon stretching. Examples of such materials include naphthalenedicarboxylic acid polyesters (e.g., polyethylene naphthalate), polycarbonates, and acrylic resins (e.g., polymethyl methacrylate). The B layer is typically made of a material that does not substantially exhibit birefringence upon stretching. Examples of such materials include copolyesters of naphthalenedicarboxylic acid and terephthalic acid. The multilayer structure can be formed by a combination of coextrusion and stretching. For example, the materials constituting the A layer and the B layer are extruded and then multilayered (e.g., using a multiplier). The resulting multilayer laminate is then stretched. The x-axis direction in the illustrated example corresponds to the stretching direction.

[0056] Commercially available reflective polarizing films include, for example, "DBEF" and "APF" manufactured by 3M, and "APCF" manufactured by Nitto Denko Corporation.

[0057] The crossed transmittance (Tc) of the reflective polarizing member (reflective polarizing film) can be, for example, 0.001% to 3%. The single transmittance (Ts) of the reflective polarizing member (reflective polarizing film) can be, for example, 43% to 49%, preferably 45% to 47%. The polarization degree (P) of the reflective polarizing member (reflective polarizing film) can be, for example, 92% to 99.99%.

[0058] The crossed transmittance, single transmittance, and degree of polarization can be measured, for example, using an ultraviolet-visible spectrophotometer. The degree of polarization P can be calculated from the obtained Tp and Tc by measuring the single transmittance Ts, parallel transmittance Tp, and crossed transmittance Tc using an ultraviolet-visible spectrophotometer, using the following formula. Note that Ts, Tp, and Tc are Y values ​​measured using a 2-degree visual field (C light source) according to JIS Z 8701 and corrected for luminosity. Polarization degree P(%)={(Tp-Tc) / (Tp+Tc)} 1 / 2 ×100

[0059] The absorptive polarizing element includes an absorptive polarizing film. The crossed transmittance (Tc) of the absorptive polarizing element (absorptive polarizing film) is preferably 0.5% or less, more preferably 0.1% or less, and even more preferably 0.05% or less. The single transmittance (Ts) of the absorptive polarizing element (absorptive polarizing film) is, for example, 41.0% to 45.0%, and preferably 42.0% or more. The degree of polarization (P) of the absorptive polarizing element (absorptive polarizing film) is, for example, 99.0% to 99.997%, and preferably 99.8% or more.

[0060] The absorptive polarizing film is typically composed of a film containing a dichroic substance such as iodine or an organic dye. The thickness of the absorptive polarizing film is, for example, 10 μm or less, preferably 9 μm or less, more preferably 8 μm or less, and even more preferably 7 μm or less. On the other hand, the thickness of the absorptive polarizing film is, for example, 1 μm or more.

[0061] For example, the absorptive polarizing film may be made of a liquid crystal compound. The thickness of the absorptive polarizing film made of a liquid crystal compound may be, for example, 4 μm or less, or may be 3 μm or less, or may be 2 μm or less.

[0062] As the liquid crystal compound, a lyotropic liquid crystal polymer is preferably used. The liquid crystal compound is typically aligned in a predetermined direction in the absorptive polarizing film, and the alignment state is fixed. Specifically, the absorptive polarizing film can be a layer in which the alignment of the liquid crystal compound is fixed. The liquid crystal phase of the liquid crystal compound may be, for example, any of a nematic phase, a smectic phase, and a columnar phase.

[0063] The lyotropic liquid crystalline polymer has, for example, a structural unit containing a ring structure, a linking group, and a sulfo group and / or a sulfonate group. The ring structure is typically contained in the main chain of the lyotropic liquid crystalline polymer. The number of ring structures contained in each structural unit is, for example, 1 or more and 5 or less. A typical example of the ring structure is an aromatic ring. Examples of the ring structure include a benzene ring, an oxazole ring, a thiazole ring, an oxadiazole ring, a biphenyl ring, and condensed rings thereof. A benzene ring is preferably used. The linking group links, for example, two ring structures. Both ends of the linking group are, for example, directly bonded to the ring structures. Examples of the linking group include sp 3 Carbon-containing linking groups include amide bonds. 3 A carbon-containing linking group is used. 3 Specific examples of the carbon-containing linking group include alkylene groups and oxyalkylene groups. Preferably, alkylene groups having 1 to 8 carbon atoms are used, and more preferably, methylene groups and ethylene groups are used.

[0064] The sulfo group and / or sulfonate group can impart water solubility and lyotropic liquid crystallinity to the lyotropic liquid crystalline polymer. The sulfo group and / or sulfonate group is, for example, directly bonded to the ring structure. The number of sulfo groups and / or sulfonate groups contained in each structural unit is, for example, 1 to 5. Representative examples of the counter cation of the sulfonate group include alkali metal cations, and preferably Li + , Na + , K. + , Rb + , Cs +By exchanging the counter cation of the sulfonate group for a cation with lower water solubility (so-called insolubilization treatment), an absorptive polarizing film with excellent water resistance can be obtained. Typical examples of cations with lower water solubility than alkali metal cations include ammonium ions and polyvalent metal cations. Typical ammonium ions used are ammonium ions of organic nitrogen compounds having two or more nitrogen atoms in the molecule. The number of nitrogen atoms contained in the organic nitrogen compound is not particularly limited, but is preferably 2 to 5, more preferably 2 to 3, and even more preferably 2. Examples of polyvalent metal cations include alkaline earth metal cations (e.g., Ca 2+ , Mg 2+ , Sr 2+ , Ba 2+ ), transition metal cations (e.g., La 3+ , Fe 3+ , Cr 3+ , Mn 2+ , Cu 2+ , Ce 3+ ), poor metal cations (e.g., Al 3+ , Pb 2+ , Sn 2+ , Zn 2+ ) are listed.

[0065] Examples of structural units of lyotropic liquid crystalline polymers include structures shown in the following formulas (1) to (23). Here, formulas (1), (3) to (10) represent structural units having an alkylene group (linking group) and a benzene ring (ring structure). Formula (2) represents a structural unit having an amide bond (linking group) and a benzene ring (ring structure). Formulas (11) to (19) represent structural units having an alkylene group (linking group) and a fused ring (ring structure). Formulas (20) to (23) represent structural units having an oxyalkylene group (linking group) and a benzene ring (ring structure). For convenience, formulas (2) to (23) below contain a sulfo group, but a sulfonate group may also be used.

[0066] [ka] (In formula (1), X represents a hydrogen atom or a counter cation selected from an ammonium ion, an alkali metal cation, an alkaline earth metal cation, a transition metal cation, or a poor metal cation.)

[0067] [ka]

[0068] [ka]

[0069] [ka]

[0070] [ka]

[0071] Among these structural units, structural units having an alkylene group (linking group) and a benzene ring (ring structure) (the above formulas (1), (3) to (10)) and structural units having an amide bond (linking group) and a benzene ring (ring structure) (the above formula (2)) are preferably used, with the structural unit represented by the above formula (1) being more preferably used. The lyotropic liquid crystalline polymer may, for example, have one of the above structural units alone, or may have a combination of multiple structural units. The lyotropic liquid crystalline polymer is preferably a homopolymer having one of the above structural units alone, more preferably a homopolymer of a structural unit represented by the above formula (1) or (2), and even more preferably a homopolymer of a structural unit represented by the above formula (1).

[0072] In the lyotropic liquid crystalline polymer, the number of repeating constitutional units is, for example, 25 to 1000. The lyotropic liquid crystalline polymer itself can be transparent and does not substantially exhibit absorption dichroism. The single transmittance of the lyotropic liquid crystalline polymer is, for example, 85% to 100%.

[0073] In one embodiment, the absorptive polarizing film made of a liquid crystal compound may contain, as a dichroic material, an organic dye capable of imparting absorptive dichroism. Examples of such organic dyes include those represented by the following formulas (24) to (26). [ka] In formula (24), A represents a sulfo group or a sulfonate group. m represents 1 or more and 4 or less. B represents a chlorine atom. p represents 0 or more and 2 or less. m+p is 4 or less. When A is a sulfonate group, its counter cation is Na + , K. + , Cs + , or NH4 + ) [ka] In formula (25), A represents a sulfo group or a sulfonate group. m represents 1 or more and 4 or less. B represents a hydroxyl group. p represents 0 or more and 4 or less. C represents a sulfonyl group. n represents 0 or more and 2 or less. R represents an oxygen atom. q represents 0 or more and 4 or less. m+p+q is 6 or less. When A is a sulfonate group, its counter cation is Na + , K. + , Cs + , or NH4 + ) [ka] In formula (26), A represents a sulfo group or a sulfonate group. When A represents a sulfonate group, its counter cation is Na + , K. + , Cs + , or NH4+ )

[0074] Further, examples of organic dyes include azo dyes, azoxy dyes, azomethine dyes, stilbene dyes, polymethine dyes, cationic dyes, naphthalene dyes, perylene dyes, and anthrone dyes described in paragraphs

[0035] to

[0037] of JP-A No. 2004-528603; stilbene dyes described in U.S. Pat. No. 5,007,942 or U.S. Pat. No. 5,340,504; and azo and metallized dyes described in European Patent No. 0 530 106, European Patent Application Publication No. 0 626 598, or U.S. Pat. No. 5,318,856.

[0075] In addition, examples of organic dyes include CI Direct Yellow 12, CI Direct Yellow 28, CI Direct Yellow 44, CI Direct Yellow 142, CI Direct Orange 6, CI Direct Orange 26, CI Direct Orange 39, CI Direct Orange 72, CI Direct Orange 107, CI Direct Red 2, CI Direct Red 31, CI Direct Red 79, CI Direct Red 81, CI Direct Red 240, CI Direct Red 247, CI Direct Violet 9, CI Direct Violet 48, CI Direct Violet 51, CI Direct Blue 1, CI Direct Blue 15, CI Direct Blue 71, CI Direct Blue 78, CI Direct Blue 98, CI Direct Blue 168, CI Direct Blue 202, CI Direct Blue 169, CI Direct Blue 170, CI Direct Blue 171, CI Direct Blue 172, CI Direct Blue 173, CI Direct Blue 174, CI Direct Blue 175, CI Direct Blue 176, CI Direct Blue 177, CI Direct Blue 178, CI Direct Blue 179 ... Direct dyes such as Direct Brown 106, CI Direct Brown 223, and CI Direct Green 85; reactive dyes such as Active Yellow 1, Active Red 1, Active Red 6, Active Red 14, Active Red 46, Active Violet 1, Active Blue 9, and Active Blue 10; acid dyes such as Acid Orange 63, Acid Red 85, Acid Red 144, Acid Red 152, Acid Brown 32, Acid Violet 50, Acid Blue 18, Acid Blue 44, Acid Blue 61, Acid Blue 102, and Acid Black 21; and cationic dyes such as Basic Red 12, Basic Brown (CI 33500), and Basic Black.

[0076] Further examples of organic dyes include organic molecules described in U.S. Patent Application Publication No. 2001 / 0029638. Specific examples include polymethine dyes (e.g., pseudoisocyanine, piacyanol), triarylmethane dyes (e.g., Basic Turquose, Acid Light Blue 3), diaminoxanthene dyes (e.g., sulforhodamine), acridine dyes (e.g., Basic Yellow K), sulfonated acridine dyes (e.g., trans-quinacridone), water-soluble derivatives of anthraquinone dyes (e.g., Activite Light Blue KX), sulfonated vat dyes (e.g., flavanthrone, indanthrene yellow, vat yellow 4K, vat dark green G, vat violet C, indanthrone, perylene violet, vat scarlet 2G), and azo dyes (e.g., benzopurpurin 4B, Direct Lightfast Yellow). O), water-soluble diazine dyes (e.g., Acid Dark Blue 3), sulfonated dioxazine dyes (e.g., Pigment Violet Dioxazine), soluble thiazine dyes (e.g., Methylene Blue), water-soluble phthalocyanine derivatives (e.g., copper octacarboxyphthalocyanine salts), cromoglycate disodium, perylenetetracarboxylic diimide red (PADR), benzimidazoles of PADR (i.e., purple), naphthalenetetracarboxylic acid (i.e., yellow, deep red-purple), phenanthro-9',10':2,3-quinoxaline, and sulfoderivatives of benzimidazoles.

[0077] Such organic dyes can be used alone or in combination of two or more. In a preferred embodiment, the organic dyes represented by the above formulas (24) to (26) are used in combination.

[0078] An absorptive polarizing film made of a liquid crystal compound can be obtained, for example, by coating a liquid crystal polymer solution prepared by dissolving the above-mentioned lyotropic liquid crystalline polymer in an aqueous solvent on a substrate, drying the liquid crystal polymer solution, and then dyeing the lyotropic liquid crystal layer. After dyeing, excess dye solution can be removed.

[0079] Examples of the aqueous solvent include water and a mixed solvent of water and alcohol, with water being preferred. The solids concentration in the liquid crystal polymer solution is, for example, 5% by mass to 30% by mass, preferably 10% by mass to 20% by mass. When applying the liquid crystal polymer solution, a primer layer (e.g., containing polyethyleneimine) may be formed on the coated surface of the substrate. The thickness of the primer layer is, for example, 10 nm to 50 nm. The liquid crystal polymer solution can be applied by a coating method capable of applying shear stress. A wire bar is typically used for application. A lyotropic liquid crystal layer can be formed by drying the coated film of the liquid crystal polymer solution. The drying temperature is, for example, 40°C to 80°C, preferably 50°C to 70°C. The drying time is, for example, 10 seconds to 10 minutes, preferably 5 minutes or less. The lyotropic liquid crystal polymer can be oriented by the shear stress during application, and the lyotropic liquid crystal layer can exhibit retardation with a slow axis in the coating direction.

[0080] The dyeing can be typically performed by immersing the lyotropic liquid crystal layer in a dye solution containing a dichroic material. The temperature of the dye solution during dyeing is, for example, from 10° C. to 50° C., preferably from 20° C. to 40° C. The immersion time (dyeing time) is, for example, from 5 seconds to 300 seconds, preferably from 30 seconds to 180 seconds.

[0081] When the dichroic substance is iodine, the dye solution preferably further contains an iodine compound, more preferably an iodine compound and a polyvalent metal salt. Examples of iodine compounds include potassium iodide, lithium iodide, sodium iodide, zinc iodide, aluminum iodide, lead iodide, copper iodide, barium iodide, calcium iodide, tin iodide, and titanium iodide. Potassium iodide is preferably used. The mass ratio of iodine to the iodine compound (iodine:iodine compound) in the dye solution is, for example, 1:5 to 1:30, preferably 1:5 to 1:15. By including a polyvalent metal salt in the dye solution, water resistance can be imparted to the absorptive polarizing film. Examples of polyvalent metal salts include chlorides, sulfates, nitrates, phosphates, oxalates, and acetates. Examples of counter metals for polyvalent metal salts include alkali metals, alkaline earth metals, transition metals, and non-metallic metals, specifically barium, aluminum, lead, chromium, strontium, cerium, lanthanum, samarium, yttrium, copper, and iron. Strontium chloride is preferably used. The mass ratio of iodine to polyvalent metal salt (iodine:polyvalent metal salt) in the dye solution is, for example, 1:5 to 1:30, and preferably 1:5 to 1:15.

[0082] When the dichroic material is an organic dye, the solids concentration of the organic dye in the dye solution is, for example, 0.1% by mass to 3.0% by mass, and preferably 1.0% by mass or more. When organic dyes represented by the above formulas (24) to (26) are used in combination, the mass ratio of formula (24):formula (25):formula (26) is, for example, 40-60:10-30:10-30.

[0083] The protective member typically includes a substrate. The substrate can be made of any appropriate film. Examples of materials that form the main component of the film constituting the substrate include cellulose-based resins such as triacetyl cellulose (TAC), polyester-based, polyvinyl alcohol-based, polycarbonate-based, polyamide-based, polyimide-based, polyethersulfone-based, polysulfone-based, polystyrene-based, cycloolefin-based resins such as polynorbornene, polyolefin-based, (meth)acrylic, and acetate-based resins. Here, (meth)acrylic refers to acrylic and / or methacrylic. The thickness of the substrate is preferably 5 μm to 80 μm, more preferably 10 μm to 50 μm, and even more preferably 15 μm to 40 μm.

[0084] The protective member is preferably composed of a laminated film having a substrate and a surface treatment layer formed on the substrate. The thickness of the laminated film is preferably 10 μm to 80 μm, more preferably 15 μm to 60 μm, and even more preferably 20 μm to 45 μm. The thickness of the surface treatment layer is preferably 0.5 μm to 10 μm, more preferably 1 μm to 7 μm, and even more preferably 2 μm to 5 μm.

[0085] The surface treatment layer typically includes a hard coat layer. The hard coat layer is typically formed by applying a hard coat layer-forming material to a substrate and curing the applied layer. The hard coat layer-forming material typically includes a curable compound as a layer-forming component. Examples of the curing mechanism of the curable compound include heat curing and photocuring. Examples of the curable compound include monomers, oligomers, and prepolymers. Preferably, a polyfunctional monomer or oligomer is used as the curable compound. Examples of the polyfunctional monomer or oligomer include a monomer or oligomer having two or more (meth)acryloyl groups, a urethane (meth)acrylate or a urethane (meth)acrylate oligomer, an epoxy-based monomer or oligomer, and a silicone-based monomer or oligomer.

[0086] The thickness of the hard coat layer is preferably 0.5 μm to 10 μm, more preferably 1 μm to 7 μm, and even more preferably 2 μm to 5 μm.

[0087] The surface treatment layer preferably includes a functional layer. The functional layer preferably functions as an antireflection layer. In a preferred embodiment, the surface treatment layer includes the hard coat layer and the antireflection layer in this order from the substrate side. The thickness of the functional layer is preferably 0.05 μm to 10 μm, more preferably 0.1 μm to 5 μm, and even more preferably 0.1 μm to 2 μm.

[0088] The surface protection film is typically a laminate of a substrate film and a pressure-sensitive adhesive layer. Materials for forming the substrate film include polyester-based polymers such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate (PBT); cellulose-based polymers such as diacetyl cellulose and triacetyl cellulose; polycarbonate-based polymers; (meth)acrylic polymers such as polymethyl methacrylate; and cycloolefin-based polymers such as polynorbornene. These may be used alone or in combination of two or more. The thickness of the substrate film is preferably 15 μm to 70 μm, more preferably 20 μm to 60 μm, and even more preferably 25 μm to 50 μm. The thickness of the pressure-sensitive adhesive layer is, for example, 5 μm to 15 μm.

[0089] The sacrificial member may typically be made of any suitable plastic film. Specific examples of plastic films include polyethylene terephthalate (PET) film, polyethylene film, and polypropylene film. As described above, the sacrificial member may function as a release liner. A plastic film whose surface is coated with a release agent is preferably used as the release liner. Examples of release agents include silicone-based release agents, fluorine-based release agents, and long-chain alkyl acrylate-based release agents.

[0090] The thickness of the sacrificial member is preferably 36 μm or more, more preferably 48 μm or more, and even more preferably 58 μm or more. Such a thickness can prevent the suction marks from remaining on a member or layer disposed adjacent to the sacrificial member. The thickness of the sacrificial member is, for example, 100 μm or less.

[0091] The sacrificial member preferably has a modulus of elasticity of 1×10 8 Pa or more, more preferably 1×10 9 Pa or more, and more preferably 2×10 9 Such an elastic modulus can prevent the suction marks from remaining on a member or layer disposed adjacent to the sacrificial member. The elastic modulus of the sacrificial member is, for example, 1×10 10 Pa or less.

[0092] As shown in the figure, each member included in the optical film 2 can be integrated via an adhesive layer. Alternatively, the optical film 2 may be provided integrally with the lens portion of the display system via an adhesive layer (for example, a pressure-sensitive adhesive layer). The adhesive layer may be formed of an adhesive or a pressure-sensitive adhesive. The thickness of the adhesive layer is, for example, 0.05 μm to 30 μm, preferably 3 μm to 20 μm, and more preferably 5 μm to 15 μm. [Example]

[0093] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. The thickness, retardation value, and modulus of elasticity are values ​​measured by the following measurement methods. Unless otherwise specified, "parts" and "%" are based on weight. <Thickness> Thicknesses of 10 μm or less were measured using a scanning electron microscope (manufactured by JEOL Ltd., product name "JSM-7100F"), and thicknesses of more than 10 μm were measured using a digital micrometer (manufactured by Anritsu Corporation, product name "KC-351C"). <Phase difference value> The phase difference value at each wavelength at 23°C was measured using a Mueller matrix polarimeter (manufactured by Axometrics, product name "Axoscan"). <Elastic modulus> The measurement object was molded into a tensile test dumbbell having a parallel part width of 10 mm and a length of 40 mm based on JIS K 6734:2000, and a tensile test was carried out in accordance with JIS K 7161:1994 to determine the tensile modulus.

[0094] [Example 1] (Fabrication of an absorption polarizing film) A primer composition was prepared according to U.S. Patent Application Publication No. 2020 / 0110209. The resulting primer composition was applied to a 25 μm thick TAC film (Konica Minolta, Inc., "KC2UA") using a wire bar, and the coated film was dried at 60° C. for 3 minutes to form a 30 nm thick primer layer. Next, a lyotropic liquid crystalline polymer consisting of the structural unit of formula (1) was dissolved in water to a solids concentration of 14% by mass. A birefringent aromatic polymer (Structure P1) was prepared as the lyotropic liquid crystalline polymer according to Example 17 of U.S. Patent Application Publication No. 2020 / 0110209. The lyotropic liquid crystalline polymer contained a sodium sulfonate base group. The resulting liquid crystalline polymer aqueous solution was applied to the primer layer using a wire bar and dried at 60°C for 3 minutes to form a 2 μm-thick lyotropic liquid crystalline layer. This material exhibited a retardation with a slow axis in the coating direction due to molecular orientation caused by shear stress during application. Next, the organic dyes represented by the above formulas (24) to (26) were prepared in accordance with U.S. Patent Application Publication No. 2020 / 0110209. Thereafter, the organic dyes represented by the above formulas (24) to (26) were dissolved in water in a mass ratio of formula (24):formula (25):formula (26) = 18:7:8 to prepare a dyeing solution with a solids concentration of 1.9 mass%. The lyotropic liquid crystal layer was then dyed by immersion in the dye solution for 90 seconds, and then insolubilized by immersion in a 10% by mass SrCl2 aqueous solution for 3 seconds. The lyotropic liquid crystal layer was then washed by immersion in pure water for 3 seconds, and then air-dried by blowing off excess water with compressed air. In this way, an absorptive polarizing film having a thickness of 2 μm was formed on the TAC film.

[0095] (Fabrication of λ / 4 components) Polymerization was carried out using a batch polymerization apparatus consisting of two vertical reactors equipped with stirring blades and reflux condensers controlled at 100° C. The polymerization mixture contained 29.60 parts by mass (0.046 mol) of bis[9-(2-phenoxycarbonylethyl)fluoren-9-yl]methane, 29.21 parts by mass (0.200 mol) of isosorbide (ISB), 42.28 parts by mass (0.139 mol) of spiroglycol (SPG), 63.77 parts by mass (0.298 mol) of diphenyl carbonate (DPC), and 1.19 × 10 calcium acetate monohydrate as a catalyst. -2 Part of mass (6.78×10 -5 (mol) was charged. After purging the reactor with nitrogen under reduced pressure, heating was performed using a heat transfer medium. Stirring was initiated when the internal temperature reached 100°C. Forty minutes after the start of the temperature increase, the internal temperature reached 220°C. This temperature was maintained while simultaneously reducing the pressure. 90 minutes after reaching 220°C, the pressure was reduced to 13.3 kPa. Phenol vapor by-produced during the polymerization reaction was introduced into a reflux condenser at 100°C, and the small amount of monomer components contained in the phenol vapor was returned to the reactor. Uncondensed phenol vapor was collected by introducing nitrogen into the first reactor and temporarily restoring the pressure to atmospheric pressure. The oligomerized reaction liquid in the first reactor was then transferred to the second reactor. Next, heating and depressurization of the second reactor were initiated, and the internal temperature reached 240°C and the pressure reached 0.2 kPa in 50 minutes. The polymerization was then allowed to proceed until the specified stirring power was reached. When the predetermined power was reached, nitrogen was introduced into the reactor to restore pressure, and the polyester carbonate resin produced was extruded into water, and the strands were cut to obtain pellets.

[0096] The resulting polyester carbonate resin pellets were vacuum-dried at 80°C for 5 hours and then used in a film-making machine equipped with a single-screw extruder (manufactured by Toshiba Machine Co., Ltd., cylinder temperature setting: 250°C), a T-die (width: 200 mm, temperature setting: 250°C), a chill roll (temperature setting: 120-130°C), and a winder to produce a 135 μm-thick long resin film. The resulting long resin film was stretched in the width direction at a stretching temperature of 143°C and a stretch ratio of 2.8 to obtain a 47 μm-thick stretched film. The resulting stretched film had an Re(550) of 143 nm, an Re(450) / Re(550) of 0.86, and an Nz coefficient of 1.12.

[0097] (Production of protective material) The hard coat layer-forming material described below was applied to an acrylic film (thickness: 40 μm) having a lactone ring structure and heated at 90°C for 1 minute. After heating, the applied layer was irradiated with a high-pressure mercury lamp at an integrated light intensity of 300 mJ / cm. 2 The coating layer was cured by irradiation with ultraviolet light of 1000 kJ / cm, thereby producing an acrylic film (thickness: 44 μm) on which a hard coat layer having a thickness of 4 μm was formed. Next, the following coating solution A for forming an antireflection layer was applied onto the hard coat layer using a wire bar, and the applied coating solution was heated at 80°C for 1 minute and dried to form a coating film. The dried coating film was then irradiated with a high-pressure mercury lamp at an integrated light intensity of 300 mJ / cm. 2 The coating was cured by irradiating it with ultraviolet light of 1000 kJ / cm 2 , thereby forming an antireflection layer A having a thickness of 140 nm. Next, the following coating solution B for forming an antireflection layer was applied onto the antireflection layer A using a wire bar, and the applied coating solution was heated at 80°C for 1 minute and dried to form a coating film. The dried coating film was irradiated with an integrated light dose of 300 mJ / cm using a high-pressure mercury lamp. 2 The coating was cured by irradiating it with ultraviolet light of 1000 kJ / cm 2 , thereby forming an antireflection layer B having a thickness of 105 nm. In this way, a protective member (thickness: 44 μm) was obtained.

[0098] (Hard Coat Layer Forming Material) A hard coat layer-forming material was prepared by mixing 50 parts of a urethane acrylic oligomer (manufactured by Shin-Nakamura Chemical Co., Ltd., "NK Oligo UA-53H"), 30 parts of a multifunctional acrylate whose main component is pentaerythritol triacrylate (manufactured by Osaka Organic Chemical Industry Ltd., trade name "Viscoat #300"), 20 parts of 4-hydroxybutyl acrylate (manufactured by Osaka Organic Chemical Industry Ltd.), 1 part of a leveling agent (manufactured by DIC Corporation, "GRANDIC PC4100"), and 3 parts of a photopolymerization initiator (manufactured by Ciba Japan, "Irgacure 907") and diluting with methyl isobutyl ketone to a solids concentration of 50%.

[0099] (Anti-reflection layer forming coating solution A) 100 parts by weight of a multifunctional acrylate (manufactured by Arakawa Chemical Industries, Ltd., trade name "Opstar KZ6728", solid content 20% by weight), 3 parts by weight of a leveling agent (manufactured by DIC Corporation, "GRANDIC PC4100"), and 3 parts by weight of a photopolymerization initiator (manufactured by BASF, trade name "OMNIRAD907", solid content 100% by weight) were mixed. The mixture was diluted with butyl acetate as a dilution solvent to a solid content of 12% by weight, and the mixture was stirred to prepare Coating Solution A for forming an antireflection layer.

[0100] (Anti-reflection layer forming coating solution B) 100 parts by weight of a polyfunctional acrylate containing pentaerythritol triacrylate as the main component (manufactured by Osaka Organic Chemical Industry Co., Ltd., trade name "Viscoat #300", solid content 100 wt%), 150 parts by weight of hollow nanosilica particles (manufactured by JGC Catalysts and Chemicals Industries, Ltd., trade name "Sururia 5320", solid content 20 wt%, weight average particle diameter 75 nm), 50 parts by weight of solid nanosilica particles (manufactured by Nissan Chemical Industries, Ltd., trade name "MEK-2140Z-AC", solid content 30 wt%, weight average particle diameter 10 nm), 12 parts by weight of a fluorine-containing additive (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "KY-1203", solid content 20 wt%), and 3 parts by weight of a photopolymerization initiator (manufactured by BASF, trade name "OMNIRAD907", solid content 100 wt%) were mixed. To this mixture, a mixed solvent of TBA (tertiary butyl alcohol), MIBK (methyl isobutyl ketone), and PMA (propylene glycol monomethyl ether acetate) in a weight ratio of 60:25:15 was added as a dilution solvent to make the total solid content 4% by weight, and the mixture was stirred to prepare coating solution B for forming an anti-reflection layer.

[0101] (Production of optical films) A reflective polarizing film ("APCF" manufactured by Nitto Denko Corporation) was attached to the above protective member (acrylic film with a hard coat layer and an anti-reflection layer) via an 11 μm thick adhesive layer, which had previously been attached to a surface protective film ("RP397CK" manufactured by Nitto Denko Corporation) consisting of a 38 μm thick PET film with a 15 μm thick adhesive layer formed thereon. The acrylic film of the protective member was attached so that it faced the reflective polarizing film. Next, the above-mentioned absorptive polarizing film alone was attached to the reflective polarizing film as an absorptive polarizing member via an 11 μm-thick adhesive layer so that the reflection axis of the reflective polarizing film and the absorption axis of the absorptive polarizing film were arranged parallel to each other. Specifically, after attachment, the TAC film (including the primer layer) was peeled off from the absorptive polarizing film. Next, the λ / 4 member was attached to the absorptive polarizing film via a 5 μm thick adhesive layer so that the absorption axis of the absorptive polarizing film and the slow axis of the λ / 4 member formed an angle of 45°. Next, a 15 μm thick adhesive layer was formed on the λ / 4 member, and a polyethylene terephthalate film (thickness 50 μm, elastic modulus 3.5×10) treated with a silicone-based release agent was applied to the surface of the adhesive layer. 9 Pa, "Diafoil MHE50" manufactured by Mitsubishi Chemical Corporation) was attached to the film to obtain a long optical film.

[0102] (Production of optical film body) The long optical film was cut to obtain a sheet-like (rectangular) optical film body as shown in Figure 1. The long side of the obtained optical film body was 310 mm long, and the short side was 230 mm long. The long side of the obtained optical film body corresponded to the width direction of the long optical film, and the short side of the obtained optical film body corresponded to the length direction of the long optical film.

[0103] (Cutting the optical film body) A holding plate with numerous through holes and 1 mm-wide through grooves was prepared, as shown in Figure 2. The optical film body was placed on the upper surface (mounting surface) of the holding plate, and the optical film body was sucked from the lower side of the holding plate to hold the optical film body. In this state, a planned cutting line was set on the optical film body as shown in Figure 1, and a 100 μm diameter laser beam was irradiated at a moving speed of 500 mm / s using a carbon dioxide laser ("TLSM-401" manufactured by Takei Electric Co., Ltd., wavelength: 9360 nm, frequency: 20 kHz) to cut the optical film body and obtain optical film pieces. During laser irradiation, the planned cutting line overlapped the through grooves in the holding plate in a planar view. Here, the length of the long side of the optical film body (310 mm) was 320 mm, and the total major diameter of the six optical film pieces present on line 1b along the long side was 320 mm. The spacing between adjacent planned cutting lines was 1.1 mm.

[0104] [Example 2] An optical film piece was obtained in the same manner as in Example 1, except that the distance between adjacent planned cutting lines was set to 0.3 mm and, accordingly, a holding plate having a large number of through holes and a through groove with a width of 0.2 mm, as shown in Figure 2, was prepared.

[0105] [Comparative Example 1] An optical film piece was obtained in the same manner as in Example 1, except that the length of the long side of the optical film body was 361 mm and the planned cutting lines (obtained optical film pieces) were not arranged in a zigzag pattern but the interval between adjacent planned cutting lines was 4 mm, as shown in Figure 6. A holding plate having through grooves corresponding to the planned cutting lines was separately prepared.

[0106] In Examples 1 and 2, the long side of the optical film body could be reduced by 14.1% compared to Comparative Example 1 while obtaining the same number (24) of optical film pieces, thereby improving yield. By reducing the long side of the optical film body, smoke and fumes generated by laser irradiation could be efficiently dissipated by the airflow in the irradiation atmosphere. Furthermore, the travel distance of the laser head could be shortened, thereby reducing takt time. Thus, the Examples are superior in terms of ESG (Environment, Social, and Governance) evaluation and production costs.

[0107] When the obtained optical film pieces were observed with an optical microscope (Olympus MX61), foreign matter (less than 150 μm in size) was found to be attached to the cutout portion in Example 2, whereas no foreign matter was found in Example 1 or Comparative Example 1. If foreign matter is attached to the cutout portion of the optical film piece, accurate positioning (e.g., alignment of the optical axis) may not be possible when integrating the optical film piece with an adherend (e.g., a lens portion). This may result in a loss of display quality in, for example, VR goggles.

[0108] The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the configurations shown in the above-described embodiment can be replaced with configurations that are substantially the same as those shown in the above-described embodiment, that have the same effects, or that can achieve the same purpose. [Industrial Applicability]

[0109] The optical film piece according to the embodiment of the present invention can be used in a display such as VR goggles, for example. [Explanation of symbols]

[0110] 1 Optical film body, 1a Cutting line, 2 Optical film piece (optical film), 2a Cutout portion, 3 Holding plate, 3a Arrangement surface, 3b Through hole, 3c Through groove, 10 Display system, 12 Display element, 14 Reflective polarizing element, 16 First lens portion, 18 Half mirror, 20 First λ / 4 element, 22 Second λ / 4 element, 24 Second lens portion, 26 User's eye, 28 Absorbent polarizing element, 30 Third λ / 4 element, 31 Protective element, 41 Adhesive layer, 42 Adhesive layer, 43 Adhesive layer, 44 Adhesive layer, 51 Surface protective film, 52 Sacrificial element.

Claims

1. Preparing an optical film body that is rectangular or square in plan view; placing the prepared optical film body on a holding plate; and irradiating the optical film body with laser light to cut the optical film body to obtain a plurality of optical film pieces. the holding plate has a through groove formed therein, the through groove corresponding to the planned cutting line of the optical film body, and allowing for the suction of products generated by the laser irradiation; a major axis of the optical film piece to be cut is disposed substantially parallel to a first side of the optical film body; the sum of the major axes of the optical film pieces to be cut that are present on a line along the first side of the optical film body is longer than the length of the first side of the optical film body; A method for manufacturing an optical film piece.

2. The manufacturing method according to claim 1 , wherein the planned cutting line of the prepared optical film body is arranged at a position that overlaps the through groove of the holding plate in a plan view.

3. The manufacturing method according to claim 1 , wherein the width of the through groove is 0.1 mm or more and 3 mm or less.

4. The manufacturing method according to claim 1 , wherein the width of the through groove is from 1 to 30 times the diameter of the irradiated laser light.

5. The method of claim 1 , wherein the optical film body includes a sacrificial member disposed directly on the holding plate.

6. The method according to claim 1 , wherein the distance between adjacent planned cutting lines in the optical film body is 3 mm or less.

7. The method according to claim 1 , wherein the distance between adjacent planned cutting lines in the optical film body is 30 times or less the diameter of the irradiated laser beam.

8. The method according to claim 1 , wherein the distance between adjacent planned cutting lines in the optical film body is 0.3 mm or more.

9. The method according to claim 1 , wherein the distance between adjacent planned cutting lines in the optical film body is at least three times the diameter of the irradiated laser beam.

10. The manufacturing method according to claim 1 , wherein the optical film piece has at least one of a cutout portion in which the outer periphery is partially cut out in a plan view and a protrusion portion in which the outer periphery is partially protruding in a plan view.

11. Preparing an optical film body that is rectangular or square in plan view; placing the prepared optical film body on a holding plate; and irradiating the optical film body with laser light to cut the optical film body to obtain a plurality of optical film pieces. the holding plate has a through groove formed therein, the through groove corresponding to the planned cutting line of the optical film body, and allowing for the suction of products generated by the laser irradiation; a major axis of the optical film piece to be cut is disposed substantially parallel to a first side of the optical film body; the sum of the major axes of the optical film pieces to be cut that are present on a line along the first side of the optical film body is longer than the length of the first side of the optical film body; How to cut optical film.

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