Optical sheet

Abstract

To provide an optical sheet that is tinted brown and allows blue light to be visually recognized with excellent visibility.SOLUTION: An optical sheet 10 of the present invention is an optical sheet formed of a laminate including a polarizing layer 4 having a polarization function and containing at least one kind of light absorber, and a protective layer 1 laminated on the polarizing layer 4. The polarizing layer 4 satisfies the following conditions: in the L*a*b* color system defined in JIS Z 8781-4, the value of a* is at least 0 and 15 or less, and the value of b* is at least 13.5 and 45 or less; the magnitude of the Q Blue value defined in the Australian / New Zealand Standard 1067-2016 is 0.70 or greater; and the luminous transmittance Tv in the visible light region is 28% or less.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an optical sheet. [Background technology]

[0002] For example, optical sheets having a polarizing function are known for the purposes of increasing the contrast of the field of view, anti-glare, etc. (See, for example, Patent Document 1.) This optical sheet is used by being attached to eyeglasses, sunglasses, sun visors, etc.

[0003] The optical sheet described in Patent Document 1 is manufactured by, for example, stretching in one direction a layer containing a resin material and a dye (light absorbing agent) dispersed in the resin material.

[0004] There are optical sheets of this type whose color is toned to brown, which is the standard color for sunglasses, etc., but in this case there is a problem that the discrimination of blue light is generally reduced. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] WO2014 / 115705 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide an optical sheet that is toned brown and can be viewed with excellent discrimination even under blue light, and an optical component that includes such an optical sheet. [Means for solving the problem]

[0007] These objects can be achieved by the present invention as set forth in (1) to (4) below. (1) An optical sheet comprising a laminate including a polarizing layer containing at least one light absorbing agent and having a polarizing function, and a protective layer laminated on the polarizing layer, The polarizing layer has a thickness of L defined in JIS Z 8781-4. * a * b * In the color system, a * The value of is between 0 and 15, and b * The value of is between 13.5 and 45, and The Q Blue value specified in Australian / New Zealand Standard 1067-2016 is 0.70 or greater, and An optical sheet having a luminous transmittance Tv of 28% or less in the visible light region.

[0008] (2) The optical sheet according to (1), wherein the polarizing layer has a luminous transmittance Tv of 10% or more and 25% or less.

[0009] (3) The optical sheet according to (1) or (2), wherein the polarizing layer has an average transmittance of 5% to 25% in the wavelength range of 460 nm to 510 nm.

[0010] (4) The optical sheet according to any one of (1) to (3), wherein the polarizing layer has an average transmittance of 1% to 5% in the wavelength range of 380 nm to 450 nm. [Effects of the Invention]

[0011] According to the present invention, an optical sheet toned to brown can be visually recognized with excellent discrimination even when illuminated with blue light. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a perspective view of sunglasses as an optical component, showing a state in which the optical sheet of the present invention is attached. [Figure 2] 1 is a partially enlarged longitudinal sectional view showing an embodiment of an optical sheet of the present invention. [Figure 3] 3 is a graph showing the light absorption spectrum of a polarizing layer included in the optical sheet shown in FIG. [Figure 4] 3 is a graph showing the light absorption spectrum of a second light-absorbing agent contained in a polarizing layer of the optical sheet shown in FIG. 2. [Figure 5] 3 is a side view schematically showing an optical sheet manufacturing apparatus for manufacturing the optical sheet shown in FIG. 2. FIG. [Figure 6] 1 is a cross-sectional view schematically showing a spectacle lens manufacturing apparatus for manufacturing spectacle lenses provided with optical sheets. DETAILED DESCRIPTION OF THE INVENTION

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The optical sheet of the present invention will be described in detail below with reference to preferred embodiments shown in the accompanying drawings.

[0014] The optical sheet 10 of the present invention is composed of a laminate including a polarizing layer 4 containing at least one light absorbing agent and having a polarizing function, and a protective layer 1 laminated on the polarizing layer 4. The polarizing layer 4 has a L * a * b * In the color system, a * The value of is between 0 and 15, and b * is 13.5 or more and 45 or less, the Q Blue value specified in Australian / New Zealand Standard 1067-2016 is 0.70 or more, and the luminous transmittance Tv in the visible light region is 28% or less. Therefore, this optical sheet 10 can be said to be an optical sheet toned to brown. Furthermore, optical sheet 10 toned to brown can be visually recognized with excellent discrimination even in the case of blue light.

[0015] The optical sheet 10 of the present invention is used by being attached to, for example, a spectacle lens 30 included in sunglasses 100 as an optical component. Therefore, before describing the optical sheet 10 of the present invention, the sunglasses 100 as an optical component, showing a state in which the optical sheet 10 of the present invention is attached, will be described below.

[0016] <Sunglasses> Fig. 1 is a perspective view of sunglasses as an optical component, showing a state in which the optical sheet of the present invention is attached. In Fig. 1, when the sunglasses are worn on the head of a user, the surface of the lens facing the user's eyes is referred to as the back surface, and the opposite surface is referred to as the front surface.

[0017] As shown in FIG. 1, the sunglasses 100 include a frame 20, spectacle lenses 30, and an optical sheet 10.

[0018] In this specification, the term "eyeglass lenses" includes both those with a light-condensing function and those without a light-condensing function.

[0019] The frame 20 is worn on the head of the user and positions the eyeglass lenses 30 in front of and near the user's eyes.

[0020] The frame 20 has a rim portion 21, a bridge portion 22, temple portions 23, and a nose pad portion 24.

[0021] The rim portions 21 are ring-shaped and are provided one for each of the right and left eyes, with spectacle lenses 30 attached to the inside thereof. This allows the user to view external information through the spectacle lenses 30.

[0022] The bridge portion 22 is rod-shaped and is positioned in front of the upper part of the user's nose when the glasses are worn on the user's head, connecting the pair of rim portions 21 together.

[0023] The temple portions 23 are temple-shaped and connected to the edge of each rim portion 21 on the opposite side to the position where the bridge portions 22 are connected. The temple portions 23 are hung over the user's ears when wearing the glasses on the user's head.

[0024] The nose pads 24 are provided on the edges of the rims 21 that correspond to the user's nose when the sunglasses 100 are worn on the head of the user, and come into contact with the user's nose, with a shape that corresponds to the contacting part of the user's nose at this time. This allows the sunglasses 100 to be kept stably worn.

[0025] The constituent materials of the components of the frame 20 are not particularly limited, and may be, for example, various metal materials, various resin materials, etc. The shape of the frame 20 is not limited to that shown in the drawings, as long as it can be worn on the user's head.

[0026] The eyeglass lenses 30 are attached to the rim portions 21. The eyeglass lenses 30 are optically transparent, plate-shaped members that are curved outward.

[0027] The constituent material of the eyeglass lens 30 is not particularly limited as long as it has optical transparency, but examples include various resin materials such as various thermoplastic resins, thermosetting resins, and various curable resins such as photocurable resins, various glass materials, and various crystalline materials, and one or more of these can be used in combination.

[0028] Examples of resin materials include polyolefins such as polyethylene, polypropylene, and ethylene-propylene copolymers, polyvinyl chloride, polystyrene, polyamide, polyimide, polycarbonate, poly-(4-methylpentene-1), ionomers, acrylic resins, polymethyl methacrylate, acrylonitrile-butadiene-styrene copolymers (ABS resins), acrylonitrile-styrene copolymers (AS resins), butadiene-styrene copolymers, polyesters such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT), polyethers, and polyether ketones (P). Examples of the resin include polyether ether ketone (PEEK), polyetherimide, polyacetal (POM), polyphenylene oxide, polysulfone, polyethersulfone, polyphenylene sulfide, polyarylate, aromatic polyester (liquid crystal polymer), polytetrafluoroethylene, polyvinylidene fluoride, other fluorine-based resins, epoxy resins, phenolic resins, urea resins, melamine resins, silicone resins, polyurethanes, etc., or copolymers, blends, polymer alloys, etc. that mainly contain these, and these can be used alone or in combination of two or more.

[0029] Examples of glass materials include soda glass, crystalline glass, quartz glass, lead glass, potassium glass, borosilicate glass, and alkali-free glass, and one or more of these can be used in combination.

[0030] Examples of crystalline materials include sapphire and quartz, and one or more of these may be used in combination.

[0031] The thickness of the eyeglass lens 30 is not particularly limited, but is preferably 0.5 mm to 5.0 mm, and more preferably 1.0 mm to 3.0 mm, for example, which allows for both relatively high strength and light weight.

[0032] In this embodiment, the optical sheet 10 is attached to the outer surface of the eyeglass lens 30, i.e., the curved convex surface, in a curved shape corresponding to this shape, thereby imparting decorativeness to the sunglasses 100. Furthermore, light in a predetermined wavelength range is selectively reflected and transmitted, and in the present invention, the optical sheet 10 is toned brown, thereby allowing the sunglasses 100 to function as sunglasses.

[0033] In such sunglasses 100, the optical sheet 10 is made of the optical sheet of the present invention. The optical sheet 10, that is, the optical sheet of the present invention, will be described below.

[0034] <Optical sheet> FIG. 2 is a partially enlarged longitudinal sectional view showing an embodiment of the optical sheet of the present invention, FIG. 3 is a graph showing a light absorption spectrum of a polarizing layer included in the optical sheet shown in FIG. 2, and FIG. 4 is a graph showing a light absorption spectrum of a second light-absorbing agent included in the polarizing layer included in the optical sheet shown in FIG.

[0035] 2, the upper side is also referred to as "upper" or "top," and the lower side is also referred to as "lower" or "bottom." In addition, in the drawings referred to in this specification, the dimensions in the thickness direction are exaggerated and differ greatly from the actual dimensions.

[0036] 2, the optical sheet 10 has a protective layer 1, an adhesive layer 15, and a polarizing layer 4, which are laminated in this order. That is, the polarizing layer 4 and the protective layer 1 are bonded together via the adhesive layer 15. In this embodiment, the polarizing layer 4 is bonded to the spectacle lens 30 with the polarizing layer 4 facing the spectacle lens 30.

[0037] Each layer constituting the optical sheet 10 will now be described. (polarizing layer) The polarizing layer 4 has the function of extracting linearly polarized light having a polarization plane in a predetermined direction from incident light (unpolarized natural light). As a result, the incident light that enters the eye through the optical sheet 10 has diffused light removed and becomes polarized.

[0038] The degree of polarization of the polarizing layer 4 is not particularly limited, but is preferably, for example, 50% or more and 100% or less, and more preferably 80% or more and 100% or less.

[0039] This polarizing layer 4 is made by uniaxially stretching a polymer film made of a resin material, and as a result, the polarizing layer 4 is endowed with the above-mentioned functions.

[0040] In the present invention, the polarizing layer 4 has an a* value of 0 to 15 and a b* value of 13.5 to 45 in the L*a*b* color system defined in JIS Z 8781-4, a Q Blue value of 0.70 or greater, and a luminous-corrected transmittance Tv in the visible light region of 28% or less, as defined in Australian / New Zealand Standard 1067-2016. Thus, when the polarizing layer 4 has an a* value of 0 to 15 and a b* value of 13.5 to 45 in the L*a*b* color system, the optical sheet 10 can be toned to brown. Furthermore, when the Q Blue value is 0.70 or greater and the luminous-corrected transmittance Tv in the visible light region of 28% or less, blue light can be visually recognized with excellent discrimination, even in the optical sheet 10 toned to brown.

[0041] The luminous transmittance Tv is a value measured in accordance with JIS T 7333:2018.

[0042] The polarizing layer 4 having such a configuration is not particularly limited, but preferably includes, for example, a first light-absorbing agent having a light absorptance peak in a wavelength range of 580 nm to 680 nm, a second light-absorbing agent having a light absorptance peak in a wavelength range of 380 nm to 430 nm, and a third light-absorbing agent having a light absorptance peak in a wavelength range of 430 nm to 580 nm, and these are adsorbed to a resin material contained in the polarizing layer 4 to dye the polarizing layer 4. By including the first light-absorbing agent, the second light-absorbing agent, and the third light-absorbing agent having a light absorptance peak in the above-mentioned wavelength ranges in the polarizing layer 4, the optical sheet 10 can be relatively easily toned to brown. That is, in the L*a*b* color system, the a* value can be relatively easily satisfied, being 0 to 15 and b* value being 13.5 to 45, preferably 2.0 to 14 and 25 to 40.

[0043] As described above, the first light absorber has a peak light absorptivity in the wavelength range of 580 nm or more and 680 nm or less. Specific examples of the first light absorber include blue dyes such as direct dyes, acid dyes, and basic dyes, and one or more of these may be used in combination.

[0044] The second light absorber has a peak light absorptance in the wavelength range of 380 nm or more and 430 nm or less, and specific examples thereof include yellow dyes such as direct dyes, acid dyes, and basic dyes, and one or more of these may be used in combination.

[0045] The third light absorber has a peak light absorptance in the wavelength range of 430 nm or more and 580 nm or less. Specific examples of the third light absorber include red dyes such as direct dyes, acid dyes, and basic dyes, and one or more of these may be used in combination.

[0046] Examples of direct dyes include azo-based, phthalocyanine-based, and dioxazine-based dyes; examples of acidic dyes include azo-based, anthraquinone-based, triphenylmethane-based, phthalocyanine-based, oxygen anthracene-based, xanthene-based, indigoid-based, nitroso group-based, and pyrazolone-based dyes; and examples of basic dyes include azo-based, triphenylmethane-based, azine-based, thiazine-based, and oxazine-based dyes. Among these, dyes are used as the first to third light absorbents depending on the positions of their respective peaks of absorbance.

[0047] Among these, the first light absorbing agent, the second light absorbing agent, and the third light absorbing agent are preferably azo dyes, and particularly preferably azo direct dyes. This allows efficient dyeing of polyvinyl alcohol (PVA) in water, ensuring reliable dyeing to the desired brown color. In other words, the optical sheet 10 can be reliably toned to brown.

[0048] Of these first to third light absorbing materials, the second light absorbing material is preferably at least one of yellow dyes (azo-based yellow dyes) represented by the following general formula (1) and the following general formula (2).

[0049] [ka] [In the general formula (1), each R1 independently represents a hydrogen atom, a methyl group, or a sodium sulfonate group.]

[0050] [ka] [In the general formula (2), each R2 independently represents a hydrogen atom, a methyl group, or a sodium sulfonate group.]

[0051] Specific examples of the yellow dyes represented by the general formula (1) and the general formula (2) include compounds represented by the following formula (1A) and the following formulas (2A) and (2B), respectively.

[0052] [ka]

[0053] [ka]

[0054] [ka]

[0055] When such a second light-absorbing agent is dyed into a transparent film, i.e., the polarizing layer 4, so that the transmittance Tt of the peak top Pt is 30% and the transmittance Th from 680 nm to 780 nm is 90% or more, as shown in Fig. 4, the average transmittance Ta in the wavelength range of 480 nm to 530 nm can be set to preferably 67% to 99%, more preferably 70% to 90%, and even more preferably 70% to 87%. By using a second light-absorbing agent having the above-mentioned characteristics, the blending amount of the light-absorbing agent can be adjusted to an appropriate amount.

[0056] Therefore, the light absorption spectrum of the polarizing layer 4 can be made to have the spectral characteristics shown in FIG.

[0057] 3 and 4, the horizontal axis represents wavelength (nm) and the vertical axis represents transmittance (%), with Fig. 3 being a graph showing the light absorption spectrum of the polarizing layer 4 and Fig. 4 being a graph showing the light absorption spectrum of the second light-absorbing agent. The transmittance on the vertical axis is assumed to correlate with the light absorbance, i.e., the larger the light absorbance, the smaller the transmittance, and vice versa.

[0058] In the optical absorption spectrum of the polarizing layer 4, the transmittance increases as the wavelength increases in the visible light region. The optical absorption spectrum of the polarizing layer 4 has no peak in the visible light region, and the transmittance steadily increases as the wavelength increases. Note that "no peak" means that the amount of change in transmittance is 30% or less in any wavelength range (30 nm) in the visible light region. In other words, in the optical absorption spectrum of the polarizing layer 4, no matter where a 30-nm wavelength range is extracted in the visible light region, the amount of change in transmittance in the extracted region is 30% or less. This makes it relatively easy to satisfy the requirement that the luminous transmittance Tv be 28% or less.

[0059] The luminous transmittance Tv may be 28% or less, but is preferably 10% to 25%, and more preferably 12% to 22%, which ensures improved visibility of blue despite the low transmittance.

[0060] Furthermore, the average transmittance of the polarizing layer 4 in the wavelength range of 460 nm to 510 nm is preferably 5% to 25%, and more preferably 7% to 22%, which can more reliably improve the visibility of blue.

[0061] In the light absorption spectrum of the polarizing layer 4, in the wavelength range of 460 nm to 510 nm, the change in transmittance of the extracted region is preferably 25% or less, and more preferably 22% or less, regardless of the position at which a 30 nm wavelength range is extracted. This can more reliably improve the visibility of blue.

[0062] Furthermore, the polarizing layer 4 preferably has an average transmittance of 1% to 5%, and more preferably 1% to 3%, in the wavelength range of 380 nm to 450 nm, which can reliably improve the visibility of blue despite the brown color.

[0063] In the light absorption spectrum of the polarizing layer 4, in the wavelength range of 380 nm to 450 nm, the amount of change in transmittance of the extracted region is preferably 10% or less, and more preferably 5% or less, regardless of the position at which a 30 nm wavelength range is extracted. This can more reliably improve the visibility of blue.

[0064] As described above, the polarizing layer 4 has a L * a * b * In the color system, a * The value of is between 0 and 15, and b * is 13.5 or more and 45 or less, the Q Blue value specified in Australian / New Zealand Standard 1067-2016 is 0.70 or more, and the luminous transmittance Tv in the visible light region is 28% or less. An optical sheet 10 including such a polarizing layer 4 allows even blue light to be seen with excellent discrimination. Therefore, when wearing the sunglasses 100, the user can clearly recognize the outlines and colors of objects and people, thereby increasing safety when wearing the sunglasses.

[0065] The contents of the first light absorber, second light absorber, and third light absorber in the polarizing layer 4 are preferably 0.0005 wt% or more and 0.12 wt% or less, and more preferably 0.002 wt% or more and 0.10 wt% or less. By adding the first light absorber, second light absorber, and third light absorber to the polarizing layer 4 at contents within these ranges, the polarizing layer 4 can reliably satisfy the a* value of 0 to 15 and the b* value of 13.5 to 45, as well as the Q Blue value of 0.70 or more and the luminous transmittance Tv in the visible light region of 28% or less.

[0066] In addition, examples of resin materials contained in the polarizing layer 4 include polyvinyl alcohol (PVA), partially formalized polyvinyl alcohol, polyethylene vinyl alcohol, polyvinyl butyral, polycarbonate, and partially saponified ethylene-vinyl acetate copolymers, and one or more of these may be used in combination.

[0067] Among these resin materials, polyvinyl alcohol (PVA) is particularly excellent in transparency, heat resistance, affinity with the first to third light absorbents, and alignment during stretching. Therefore, the polarizing layer 4 containing PVA as the main material has excellent heat resistance and polarizing function.

[0068] Among the resin materials contained in the polarizing layer 4, polycarbonate is a material that is excellent in light transmittance, heat resistance, and strength. Therefore, the polarizing layer 4 that is mainly made of polycarbonate has excellent strength.

[0069] The polycarbonate is not particularly limited and various types can be used, but aromatic polycarbonates are preferred. Aromatic polycarbonates have aromatic rings in their main chains, which can improve the strength of the optical sheet 10.

[0070] In addition to the above-mentioned first to third light absorbents and resin material, the polarizing layer 4 may further contain an additive such as an ultraviolet absorber that absorbs ultraviolet light (light with a wavelength range of 100 nm or more and 420 nm or less).

[0071] The thickness of the polarizing layer 4 is not particularly limited, and is preferably, for example, from 5 μm to 60 μm, and more preferably from 10 μm to 40 μm, which ensures that the polarizing layer 4 has the above-described function as the polarizing layer 4.

[0072] (protective layer) The protective layer 1 is located on the outermost side when the optical sheet 10 is bonded to the eyeglass lens 30 , and has the function of protecting the layer located inside the protective layer 1 , that is, the polarizing layer 4 .

[0073] The material constituting the protective layer 1 is not particularly limited as long as it has optical transparency, and examples thereof include various resin materials, various glass materials, etc. The resin material is not particularly limited, and examples thereof include the same materials as the resin material of the polarizing layer 4 described above, but it is preferable that the resin material be the same type as the resin material of the polarizing layer 4.

[0074] The protective layer 1 is preferably stretched in one direction, and the stretching degree is preferably 1% to 10%, more preferably 2% to 8%. The stretching direction preferably coincides with the stretching direction of the polarizing layer 4. This can improve the polarization characteristics of the optical sheet 10 as a whole.

[0075] Furthermore, the thickness of the protective layer 1 is not particularly limited, and is preferably, for example, from 10 μm to 100 μm, and more preferably from 30 μm to 60 μm, so that the protective layer 1 can reliably function.

[0076] (adhesive layer) The adhesive layer 15 has the function of bonding the polarizing layer 4 and the protective layer 1 together.

[0077] The adhesive (or pressure-sensitive adhesive) constituting the adhesive layer 15 is not particularly limited, and examples thereof include acrylic adhesives, urethane adhesives, epoxy adhesives, and silicone adhesives. Among these, urethane adhesives are preferred. This allows the adhesive layer 15 to have excellent transparency, adhesive strength, and durability, while also having excellent adaptability to shape changes.

[0078] The thickness of the adhesive layer 15 is not particularly limited, but is preferably 5 μm or more and 60 μm or less, and more preferably 10 μm or more and 40 μm or less, for example, so that the function of the adhesive layer 15 can be reliably imparted.

[0079] The optical sheet 10 as described above preferably has a total thickness of 0.1 mm or more and 2 mm or less.

[0080] The optical sheet 10 described above and the eyeglass lens 30 provided with the optical sheet 10 can be manufactured by, for example, applying the following methods for manufacturing an optical sheet and a method for manufacturing an eyeglass lens provided with the optical sheet. Note that the following describes an example in which an optical sheet is manufactured using an extrusion method.

[0081] <Method of manufacturing optical sheets> First, before describing the method for manufacturing an optical sheet, an optical sheet manufacturing apparatus will be described.

[0082] Fig. 5 is a side view that schematically shows an optical sheet manufacturing apparatus that manufactures the optical sheet shown in Fig. 2. In the following description, the upper side in Fig. 5 will be referred to as "upper" and the lower side as "lower."

[0083] The optical sheet manufacturing apparatus 1000 shown in FIG. 5 includes a sheet supply unit 200 and a sheet forming unit 300.

[0084] In this embodiment, the sheet supply section 200 is composed of an extruder 210 and a T-die 220 connected via a pipe to a molten resin discharge section of the extruder 210. A strip-shaped sheet 1' in a molten or softened state is supplied to the sheet forming section 300 by this T-die 220.

[0085] The T-die 220 is an extrusion molding unit that extrudes the sheet 1' in a molten or softened state into a strip-shaped sheet by an extrusion method. The constituent materials of each layer that makes up the optical sheet 10 described above are sequentially loaded into the T-die 220 in a molten state, and by extruding this molten material from the T-die 220, the strip-shaped sheet 1' is continuously fed out.

[0086] The sheet forming unit 300 has a touch roll 310, a cooling roll 320, and a rear-stage cooling roll 330. These rolls are configured to rotate independently by a motor (driving means) (not shown), and are cooled and continuously fed out by the rotation of these rolls. By continuously feeding the sheet 1' into the sheet forming unit 300, the surface of the sheet 1' is flattened, and the sheet 1' is cooled to a desired thickness. Then, by appropriately selecting the constituent materials of each layer constituting the optical sheet 10 to be loaded into the extruder 210 (T-die 220), the polarizing layer 4 or the protective layer 1 is obtained as the cooled sheet 1'. The polarizing layer 4 and the protective layer 1 are then bonded to each other via an adhesive layer 15, and the resulting product is cut to a predetermined length to obtain the optical sheet 10.

[0087] The optical sheet 10 is manufactured by the method for manufacturing the optical sheet 10 using the optical sheet manufacturing apparatus 1000 as described above.

[0088] The method for manufacturing the optical sheet 10 using the optical sheet manufacturing apparatus 1000 includes an extrusion step, a molding step, a cooling step, a joining step, and a cutting step.

[0089] <1A> First, a strip-shaped sheet 1' in a molten or softened state is extruded (extrusion step).

[0090] In this extrusion process, the constituent materials of each layer that constitutes the optical sheet 10 are sequentially loaded into the extruder 210. Furthermore, the constituent materials of each layer that constitutes the optical sheet 10 are in a molten or softened state within the extruder 210.

[0091] <2A> Next, the surface of the sheet 11' is flattened, and the sheet 11' is set to a predetermined thickness (forming step). This step is carried out between a touch roll 310 and a cooling roll 320.

[0092] <3A> Next, the surface of the sheet 1' is cooled (cooling step). This step is carried out between the cooling roll 320 and the rear cooling roll 330.

[0093] The above-described steps <1A> to <3A> can be repeatedly performed by appropriately selecting the constituent materials of each layer of the optical sheet 10 to be loaded into the extruder 210, thereby obtaining the polarizing layer 4 and the protective layer 1, respectively.

[0094] <4A> Next, an adhesive for forming the adhesive layer 15 is applied onto the protective layer 1, and the coating is dried to form the adhesive layer 15. The protective layer 1 and the polarizing layer 4 are bonded together so that the adhesive layer 15 is interposed between the protective layer 1 and the polarizing layer 4 (bonding step).

[0095] As a result, the polarizing layer 4 and the protective layer 1 are bonded together via the adhesive layer 15, and a laminate in which the polarizing layer 4, the adhesive layer 15, and the protective layer 1 are laminated in this order can be obtained.

[0096] <5A> Next, the obtained laminate is cut to a predetermined length (cutting step). As a result, an optical sheet 10 can be obtained in which the polarizing layer 4 and the protective layer 1 are bonded together via the adhesive layer 15.

[0097] The optical sheet 10 is obtained through the above steps. Next, a method for manufacturing a spectacle lens, which manufactures a spectacle lens 30 provided with this optical sheet 10, will be described.

[0098] <Method for manufacturing eyeglass lenses provided with optical sheets> First, before describing a method for manufacturing a spectacle lens provided with an optical sheet, a spectacle lens manufacturing apparatus will be described.

[0099] FIG. 6 is a cross-sectional view that schematically shows a spectacle lens manufacturing apparatus that manufactures spectacle lenses provided with optical sheets.

[0100] The eyeglass lens manufacturing apparatus 400 shown in Fig. 6 has a resin supply unit 500 and a mold 600. The resin supply unit 500 is filled with the constituent material (lens material) of the eyeglass lens 30 described above. The mold 600 has a cavity 610 and a supply port 620 that communicates between the inside and outside of the cavity 610. The mold 600 is also made up of an upper member 630 and a lower member 640, and when these are assembled together, the mold 600 that defines the eyeglass lens manufacturing apparatus 400 is configured.

[0101] The eyeglass lens 30 provided with the optical sheet 10 is manufactured by the method for manufacturing an eyeglass lens provided with an optical sheet using the eyeglass lens manufacturing apparatus 400 as described above.

[0102] The method for manufacturing a spectacle lens provided with an optical sheet includes an optical sheet arrangement step and a lens material supply step.

[0103] <1B> First, in a state in which the upper member 630 and the lower member 640 are disassembled, the optical sheet 10 manufactured by the optical sheet manufacturing method described above is placed on the bottom surface 641 of the lower member 640 so that the protective layer 1 faces the bottom surface 641 (optical sheet placement step). The bottom surface 641 is a curved concave surface, which allows a curved surface to be formed on the eyeglass lens 30. Furthermore, the optical sheet 10 is flexible, so it is placed following the shape of the bottom surface 641.

[0104] <2B> Next, the upper member 630 and the lower member 640 are assembled, and a molten or softened lens material is poured through the supply port 620 (lens material supply step). The molten or softened lens material is then cooled to obtain a laminate in which the optical sheet 10 and the eyeglass lens 30 are stacked, i.e., the eyeglass lens 30 to which the optical sheet 10 is attached.

[0105] Although the so-called sheet insert method has been described above as an example, the eyeglass lens 30 provided with the optical sheet 10 is not limited to this, and may be configured, for example, such that the optical sheet 10 is laminated onto a molded eyeglass lens 30 via an adhesive layer.

[0106] The above describes a preferred embodiment of the present invention, but the present invention is not limited to the above, and modifications and improvements within the scope of achieving the object of the present invention are included in the present invention.

[0107] For example, each part constituting the optical sheet of the present invention can be replaced with any other part having a similar function.

[0108] Furthermore, the optical sheet of the present invention may have any additional components in addition to the above-mentioned components.

[0109] More specifically, for example, the optical sheet of the present invention may include an intermediate layer, a power adjusting layer for adjusting the power of the lens, and the like.

[0110] Furthermore, the optical sheet of the present invention is not limited to being attached to eyeglass lenses as described in the above embodiment, but can also be used for optical components such as those attached to the brim of a sun visor, or curved window members of vehicles such as automobiles, motorcycles, and trains, as well as aircraft, ships, and houses. [Example]

[0111] The present invention will be described in more detail below based on examples. 1. Preparation of Light Absorber (Light Absorber 1) As the first light absorber, a blue dye represented by the following formula (DB-85) was prepared.

[0112] [ka]

[0113] (Second light absorber) As the second light absorber, yellow dyes represented by the following formula (1A), (2A), (3A), and (4A) were prepared.

[0114] [ka]

[0115] [ka]

[0116] [ka]

[0117] [ka]

[0118] (Third light absorber) As the third light absorber, a red dye represented by the following formula (DR-81) was prepared.

[0119] [ka]

[0120] 2. Creating optical sheets [Example 1] [1] First, a polyvinyl alcohol film (Kuraray Vinylon #7500 manufactured by Kuraray Co., Ltd.) was stretched in a water tank and dyed with an aqueous solution in which the first to third light absorbents shown in Table 1 were dissolved, and then the film was immersed in a boric acid solution, washed with water, and dried to obtain a polarizing layer 4.

[0121] When dissolving the dye, the first light absorber, the second light absorber, and the third light absorber were dissolved so that the blending amounts of the first light absorber, the second light absorber, and the third light absorber would be 0.90 parts by weight, 2.3 parts by weight, and 0.64 parts by weight, respectively, relative to 100 parts by weight of polyvinyl alcohol after drying. The resulting polarizing layer 4 had a thickness of 0.02 mm.

[0122] Furthermore, the polarizing layer 4 was measured in the L*a*b* color system defined in JIS Z 8781-4 using a spectrophotometer V-660 manufactured by JASCO Corporation, and the results were that the L* value was 50.9, the a* value was 6.1, and the b* value was 34.6.

[0123] Furthermore, the Q Blue value of the polarizing layer 4, as defined in Australian / New Zealand Standard 1067-2016, was measured using a spectrophotometer V-660 manufactured by JASCO Corporation, and the result was that the Q Blue value was 0.77.

[0124] Furthermore, the optical absorption spectrum of the polarizing layer 4 was measured using a JASCO V-660 spectrophotometer to determine the luminous transmittance Tv in the visible light region and the average transmittance in the wavelength region of 380 nm to 450 nm. The luminous transmittance Tv in the visible light region was 19.2%, and the average transmittance in the wavelength region of 380 nm to 450 nm was 2.5%.

[0125] [2] Next, 100 parts by weight of bisphenol A polycarbonate (manufactured by Mitsubishi Engineering Plastics Corporation, "Iupilon E2000FN E5100") was prepared as a protective layer-forming material, and the protective layer-forming material was placed in the extruder 210 of the optical sheet manufacturing apparatus 1000 shown in Fig. 5, melted, and extruded through a T-die 220 to obtain a protective layer 1. The thickness of the obtained protective layer 1 was 0.325 mm.

[0126] [3] Next, a two-component moisture-curing polyurethane adhesive (base: Mitsui Chemicals' "Takelac A-520", curing agent: Mitsui Chemicals' "Takenate A-50") was applied to one surface of the protective layer 1 using a bar coater so that the thickness after drying would be 20 μm. The protective layer 1 with the adhesive applied was placed in an oven and heated to dry the solvent in the adhesive, resulting in a laminate in which an adhesive layer 15 was laminated on one surface of the protective layer 1. The laminate in which the adhesive layer 15 was laminated on the protective layer 1 was then bonded to the polarizing layer 4 so that the adhesive layer 15 was interposed between the protective layer 1 and the polarizing layer 4, thereby obtaining an optical sheet 10.

[0127] [Examples 2 and 3, Comparative Example 1] The optical sheets of Examples 2 and 3 and Comparative Example 1 were obtained in the same manner as in Example 1, except that the types and contents of the first to third light absorbents used to form the optical sheet 10 were changed as shown in Table 1.

[0128] 3.Evaluation of optical sheets The optical sheets of the examples and comparative examples were evaluated by the following methods.

[0129] (Blue color discrimination evaluation) A photograph of a blue object was taken through the optical sheet manufactured as described above, and 10 people were asked to check whether they could distinguish the blue color from the photograph.

[0130] ○: 10 out of 10 people can be identified ×: Some people cannot be identified

[0131] The evaluation results of the optical sheets of the Examples and Comparative Examples obtained as described above are shown in Table 1 below.

[0132] [Table 1]

[0133] As shown in Table 1, in the optical sheets toned to brown in each example, the polarizing layer 4 has a L* a * b * In the color system, a * The value of is between 0 and 15, and b * The value of this test was between 13.5 and 45, the Q Blue value was 0.70 or greater as specified in Australian / New Zealand Standard 1067-2016, and the visually corrected transmittance Tv in the visible light range was 28% or less, so that the test was able to provide excellent visibility even with blue light.

[0134] In contrast to this, the optical sheet toned to brown in the comparative example did not satisfy the above requirements, and as a result, blue light could not be distinguished. [Explanation of symbols]

[0135] 1 protective layer 1' sheet 4 Polarizing layer 10 Optical Sheet 15 Adhesive layer 20 frames 21 Rim 22 Bridge section 23 Temple 24 Nose pad section 30 Eyeglass lenses 100 sunglasses 200 Sheet supply unit 210 Extruder 220 T-die 300 Sheet forming section 310 Touch Roll 320 Cooling Roll 330 Rear cooling roll 400 Eyeglass lens manufacturing equipment 500 Resin supply section 600 molds 610 Cavity 620 Supply port 630 Upper member 640 Lower member 641 bottom 1000 Optical sheet manufacturing equipment Pt Peak Top Ta average transmittance Th transmittance Tt transmittance TV luminous correction transmittance

Claims

1. An optical sheet comprising a laminate including a polarizing layer containing at least one light absorbing agent and having a polarizing function, and a protective layer laminated on the polarizing layer, The polarizing layer has a L defined in JIS Z 8781-4. ＊ a ＊ b ＊ In the color system, a ＊ The value of b is 0 or more and 15 or less, ＊ The value of is 13.5 or more and 45 or less, and The Q Blue value as defined in Australian Standard Australian / New Zealand Standard 1067-2016 is 0.70 or more, and An optical sheet having a luminous transmittance Tv of 28% or less in the visible light region.

2. 2. The optical sheet according to claim 1, wherein the luminous transmittance Tv of the polarizing layer is 10% or more and 25% or less.

3. 2. The optical sheet according to claim 1, wherein the polarizing layer has an average transmittance of 5% to 25% in a wavelength range of 460 nm to 510 nm.

4. 2. The optical sheet according to claim 1, wherein the polarizing layer has an average transmittance of 1% to 5% in a wavelength range of 380 nm to 450 nm.

Images