Optical laminate

Abstract

To provide an optical laminate with which, while preventing damage to a polarization film, inadvertent separation of any layer can be prevented at the time of hot bending molding.SOLUTION: An optical laminate 10 according to the present invention is characterized by comprising: a polarization film 4; a first resin layer 2 provided on a first surface side of the polarization film 4 and including mainly polycarbonate; a second resin layer 3 provided on the other side of the polarization film 4 and including mainly polycarbonate; a first adhesive layer 5 provided between the polarization film 4 and the first resin layer 2, for adhering these; and a second adhesive layer 6 provided between the polarization film 4 and the second first resin layer 3, for adhering these. The polarization film 4 contains boric acid, the concentration of which is 5.0 wt% to 10.0 wt% inclusive, and the first adhesive layer 5 and second adhesive layer 6 respectively have a storage elastic modulus at 23°C, G'(23°C), of 3.0 MPa to 200.0 MPa inclusive.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] Optical components such as eyeglasses and sunglasses have a lens layer made of a light-transmitting material such as a resin material or a glass material, and an optical function layer laminated on the lens layer and containing a filler that optically acts on light passing through the lens layer (see, for example, Patent Document 1).

[0003] In the optical component described in Patent Document 1, the optical function layer is composed of a half-mirror layer in which metal films are laminated in multiple layers on a lens layer. Therefore, when viewed from the outside, the optical component appears to sparkle, enhancing the design and making it difficult for the user's eyes to be seen from the outside. In addition, it can exert an anti-glare effect and reduce eye fatigue.

[0004] However, the lens layer often has a curved surface, and in a configuration in which the optical function layer is bonded to this curved surface, the optical function layer may be subjected to a thermal bending process before bonding the lens layer and the optical function layer. In this case, the optical function layer may be damaged, resulting in a decrease in polarization function or interlayer delamination in the optical function layer. Until now, sufficient research has not been conducted on this issue. [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 laminate that can prevent damage to a polarizing film and unintentional peeling of each layer during heat bending molding. [Means for solving the problem]

[0007] These objects can be achieved by the present invention as set forth in (1) to (4) below. (1) a polarizing film; a first resin layer provided on one surface of the polarizing film and containing mainly polycarbonate; a second resin layer provided on the other surface of the polarizing film and containing mainly polycarbonate; a first adhesive layer provided between the polarizing film and the first resin layer to bond them together; a second adhesive layer provided between the polarizing film and the second resin layer to bond them together, the polarizing film contains boric acid at a concentration of 5.0% by weight or more and 10.0% by weight or less; An optical laminate, wherein the first adhesive layer and the second adhesive layer each have a storage modulus G' (23°C) at 23°C of 3.0 MPa or more and 200.0 MPa or less.

[0008] (2) The optical laminate according to (1), wherein the first adhesive layer and the second adhesive layer each have a storage modulus G'(130°C) at 130°C of 0.5 MPa or more and 15.0 MPa or less.

[0009] (3) The optical laminate according to (1) or (2) above, wherein G'(23°C) / G'(130°C) is 5 or more and 30 or less.

[0010] (4) The optical laminate according to any one of (1) to (3) above, wherein the first adhesive layer and the second adhesive layer contain polyurethane. [Effects of the Invention]

[0011] According to the present invention, damage to the polarizing film can be prevented and unintended peeling of each layer can be prevented during the heat bending molding of the optical laminate. [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 laminate of the present invention is attached. [Figure 2] 1 is a partially enlarged longitudinal sectional view showing an embodiment of an optical laminate of the present invention. [Figure 3] FIG. 3 is a side view that schematically shows an optical laminate manufacturing apparatus that manufactures the optical laminate shown in FIG. [Figure 4] FIG. 1 is a cross-sectional view schematically showing a spectacle lens manufacturing apparatus for manufacturing spectacle lenses provided with an optical laminate. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, the optical layered body of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

[0014] The optical laminate 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 laminate 10 of the present invention, sunglasses 100 as an optical component, showing a state in which the optical laminate 10 of the present invention is attached, will be described below.

[0015] <Sunglasses> Fig. 1 is a perspective view of sunglasses as an optical component, showing a state in which the optical laminate 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.

[0016] As shown in FIG. 1, the sunglasses 100 include a frame 20, spectacle lenses 30, and an optical laminate 10.

[0017] In this specification, the term "eyeglass lenses" includes both those with a light-condensing function and those without a light-condensing function.

[0018] 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.

[0019] The frame 20 has a rim portion 41, a bridge portion 42, temple portions 43, and a nose pad portion 44.

[0020] The rim portions 41 are ring-shaped, and one is provided for each of the right and left eyes, with the spectacle lenses 30 attached to the inside thereof. This allows the user to view external information through the spectacle lenses 30.

[0021] The bridge portion 42 is rod-shaped and is positioned in front of the upper part of the user's nose when the headset is worn on the user's head, connecting the pair of rim portions 41 together.

[0022] The temple portions 43 are shaped like temples and are connected to the edges of the rim portions 41 on the opposite side to the positions where the bridge portions 42 are connected. The temple portions 43 are placed over the user's ears when the glasses are worn on the user's head.

[0023] The nose pads 44 are provided on the edges of the rims 41 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.

[0024] 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.

[0025] The eyeglass lenses 30 are attached to the rim portions 41. The eyeglass lenses 30 are optically transparent, plate-shaped members that are curved outward.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] Examples of crystalline materials include sapphire and quartz, and one or more of these may be used in combination.

[0030] 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.

[0031] In this embodiment, as shown in Fig. 2, the optical laminate 10 is attached in a curved shape corresponding to the outer surface of the eyeglass lens 30, i.e., the curved convex surface, thereby imparting decorativeness and polarization performance to the sunglasses 100.

[0032] In such sunglasses 100, the optical laminate 10 is made of the optical laminate of the present invention. The optical laminate 10 will be described below.

[0033] <Optical laminate> FIG. 2 is a partially enlarged longitudinal sectional view showing an embodiment of the optical laminate of the present invention.

[0034] 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.

[0035] 2, the optical laminate 10 has a first resin layer 2, a first adhesive layer 5, a polarizing film 4, a second adhesive layer 6, and a second resin layer 3, which are laminated in this order. That is, the polarizing film 4 is bonded to the first resin layer 2 via the first adhesive layer 5, and is bonded to the second resin layer 3 via the second adhesive layer 6. The first resin layer 2 is bonded to the spectacle lens 30 with the first resin layer 2 facing the spectacle lens 30.

[0036] Each layer constituting this optical laminate 10 will be described below. (Polarizing film 4) The polarizing film 4 has the function of extracting linearly polarized light having a polarization plane in a predetermined direction from incident light (unpolarized natural light), thereby making the incident light that enters the eye through the optical laminate 10 polarized.

[0037] The polarization degree of the polarizing film 4 is not particularly limited, but is preferably, for example, from 50% to 100%, and more preferably from 80% to 100%. The visible light transmittance of the polarizing film 4 is not particularly limited, but is, for example, preferably from 10% to 80%, and more preferably from 20% to 50%.

[0038] The material for forming such polarizing film 4 is not particularly limited as long as it has the above-mentioned function. Examples include a polymer film made of polyvinyl alcohol (PVA), partially formalized polyvinyl alcohol, polyethylene vinyl alcohol, polyvinyl butyral, polycarbonate, ethylene-vinyl acetate copolymer partially saponified product, or the like, which is dyed by adsorbing iodine or a dichroic substance such as a dichroic dye, and then uniaxially stretched, and a polyene-based oriented film such as a dehydrated product of polyvinyl alcohol or a dehydrochlorinated product of polyvinyl chloride.

[0039] Among these, the polarizing film 4 is preferably a polymer film whose main material is polyvinyl alcohol (PVA) that has been dyed with iodine or a dichroic dye and then uniaxially stretched. Polyvinyl alcohol (PVA) is a material that excels in transparency, heat resistance, affinity with the dyeing agent iodine or a dichroic dye, and orientation during stretching. Therefore, the polarizing film 4 whose main material is PVA has excellent heat resistance and polarizing function.

[0040] Examples of the dichroic dye include chloratin fast red, Congo red, brilliant blue 6B, benzopurpurine, chlorazol black BH, direct blue 2B, diamine green, chrysophenone, sirius yellow, direct fast red, and acid black.

[0041] The thickness of the polarizing film 4 is not particularly limited, and is preferably, for example, 5 μm or more and 60 μm or less, and more preferably 10 μm or more and 40 μm or less.

[0042] (1st resin layer 2, 2nd resin layer 3) The first resin layer 2 and the second resin layer 3 have the function of protecting the polarizing film 4. The first resin layer 2 is located on the curved concave surface side, and the second resin layer 3 is located on the curved convex surface side.

[0043] The first resin layer 2 and the second resin layer 3 mainly contain polycarbonate. "Mainly contain polycarbonate" means that the content of polycarbonate in the first resin layer 2 is 70% by weight or more. The same applies to the second resin layer 3.

[0044] The polycarbonate contained in the first resin layer 2 and the polycarbonate contained in the second resin layer 3 may be the same type or may have different compositions.

[0045] 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 laminate 10.

[0046] The aromatic polycarbonate is synthesized, for example, by an interfacial polycondensation reaction between bisphenol and phosgene, or an ester exchange reaction between bisphenol and diphenyl carbonate.

[0047] Examples of bisphenols include bisphenol A and bisphenol (modified bisphenol) which is the origin of the repeating unit of polycarbonate represented by the following formula (1).

[0048] [ka] (In formula (1), X represents an alkyl group, aromatic group, or cycloaliphatic group having 1 to 18 carbon atoms; Ra and Rb each independently represent an alkyl group having 1 to 12 carbon atoms; m and n each represent an integer of 0 to 4; and p represents the number of repeating units.)

[0049] Specific examples of bisphenols that are the source of the repeating units of the polycarbonate represented by formula (1) include 4,4'-(pentane-2,2-diyl)diphenol, 4,4'-(pentane-3,3-diyl)diphenol, 4,4'-(butane-2,2-diyl)diphenol, 1,1'-(cyclohexanediyl)diphenol, 2-cyclohexyl-1,4-bis(4-hydroxyphenyl)benzene, 2,3-biscyclohexyl-1,4-bis(4-hydroxyphenyl)benzene, 1,1'-bis(4-hydroxy-3-methylphenyl)cyclohexane, and 2,2'-bis(4-hydroxy-3-methylphenyl)propane, and these can be used alone or in combination of two or more.

[0050] In particular, it is preferable that the polycarbonate contains, as a main component, a bisphenol-type polycarbonate having a skeleton derived from bisphenol. By using such a bisphenol-type polycarbonate, the optical laminate 10 exhibits even greater strength.

[0051] The thicknesses of the first resin layer 2 and the second resin layer 3 are not particularly limited, but are preferably 0.1 mm or more and 15 mm or less, and more preferably 0.2 mm or more and 5 mm or less, thereby ensuring sufficient strength of the optical laminate 10. The first resin layer 2 and the second resin layer 3 may have different thicknesses.

[0052] (First adhesive layer 5 and second adhesive layer 6) The adhesive (or pressure-sensitive adhesive) constituting the first adhesive layer 5 and the second adhesive layer 6 is not particularly limited, and examples thereof include acrylic adhesives, urethane adhesives, epoxy adhesives, and silicone adhesives. Among these, urethane adhesives, particularly those containing polyurethane, are preferred. This can improve the transparency, adhesive strength, and durability of the first adhesive layer 5 and the second adhesive layer 6, while also improving their ability to adapt to shape changes.

[0053] The thickness of the first adhesive layer 5 and the second adhesive layer 6 is not particularly limited, and 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. This ensures that the functions of the first adhesive layer 5 and the second adhesive layer 6 can be properly imparted. The first adhesive layer 5 and the second adhesive layer 6 may have different thicknesses.

[0054] The optical laminate 10 as described above preferably has a total thickness of 0.1 mm or more and 2 mm or less.

[0055] As described above, the optical laminate 10 is used by being attached to the curved convex surface of the eyeglass lens 30. That is, the optical laminate 10 is heat-bent into a curved state and then bonded to the eyeglass lens 30 in that curved state before use. The heat-bending process is performed, for example, using a Rema molding machine (vacuum molding machine) (CR-32 type) by suctioning the laminate at approximately 150°C for approximately 10 minutes to curve it. During this heat-bending process, damage to the polarizing film 4 can accumulate, causing problems such as streaks of light leakage through the polarizing film 4 or partial peeling of the first resin layer 2 or the second resin layer 3 from the polarizing film 4 due to deterioration of the first adhesive layer 5 and the second adhesive layer 6. The optical laminate 10 can solve these problems by satisfying the following requirements A and B.

[0056] Requirement A: The polarizing film 4 contains boric acid, and the concentration (hereinafter referred to as "boric acid concentration") is 5.0% by weight or more and 10.0% by weight or less. Requirement B: The first adhesive layer 5 and the second adhesive layer 6 each have a storage modulus G' (23°C) at 23°C of 3.0 MPa or more and 200.0 MPa or less.

[0057] By satisfying these requirements A and B, damage to the polarizing film 4 during the heat bending process can be prevented, and partial peeling of the first resin layer 2 or the second resin layer 3 from the polarizing film 4 can also be prevented.

[0058] If requirement A is not satisfied, the polarizing film 4 will be damaged during heat bending, resulting in streaky light leakage. Specifically, if the boric acid concentration is too low, the orientation of the PVA molecules cannot be maintained during molding, and the orientation of the dye adsorbed to the PVA molecular chains will be disrupted, resulting in a decrease in polarization. On the other hand, if the boric acid concentration is too high, the flexibility of the polarizing film will be reduced, resulting in cracks in the polarizing film during bending or injection molding.

[0059] If requirement B is not satisfied, the first resin layer 2 or the second resin layer 3 will partially peel off from the polarizing film 4. Specifically, if the storage modulus G' (23°C) of the first adhesive layer 5 and the second adhesive layer 6 is too low, they will not be able to maintain their adhesive strength against shear stress, and shear stress will be applied to the polarizing film 4, causing peeling. On the other hand, if the storage modulus G' (23°C) of the first adhesive layer 5 and the second adhesive layer 6 is too high, the first adhesive layer 5 and the second adhesive layer 6 will not be able to follow deformation of the polarizing film 4 as well, and they will not be able to maintain their adhesive strength against impact or edge peeling, causing peeling.

[0060] The boric acid content was measured by titrating a test solution prepared by dissolving the polarizing film 4 in water with heating using a neutralization titration method.

[0061] In addition, the storage modulus G' (23°C) of the first adhesive layer 5 and the second adhesive layer 6 can be obtained in accordance with JIS K7244-4 by preparing adhesive layers 16 and 17 having a width of 4 mm and a length of 20 mm, and measuring them using a dynamic viscoelasticity measuring device (manufactured by SII NanoTechnology Inc., "DMS6100") in tensile mode, at a frequency of 1 Hz, and at a heating rate of 5°C / min.

[0062] The boric acid concentration in the polarizing film 4 may be from 5.0 to 10.0% by weight, more preferably from 5.1 to 9.8% by weight, and even more preferably from 5.5 to 8.0% by weight, which more effectively prevents damage to the polarizing film 4 during the heat bending process.

[0063] The storage modulus G' (23°C) of the first adhesive layer 5 and the second adhesive layer 6 at 23°C may be from 3.0 MPa to 200.0 MPa, preferably from 3.5 MPa to 180.0 MPa, and more preferably from 4.0 MPa to 160.0 MPa, which can more effectively prevent the first resin layer 2 or the second resin layer 3 from being partially peeled off from the polarizing film 4 due to the heat bending process.

[0064] The storage modulus G'(130°C) of each of the first adhesive layer 5 and the second adhesive layer 6 at 130°C is preferably 0.5 MPa or more and 15.0 MPa or less, and more preferably 1.0 MPa or more and 14.0 MPa or less, which can more effectively prevent peeling during hot bending.

[0065] G'(23°C) / G'(130°C) is preferably 5 or more and 30 or less, and more preferably 6 or more and 27 or less, thereby making it possible to more reliably exert the above-mentioned effects.

[0066] The first adhesive layer 5 and the second adhesive layer 6 may have the same or different storage moduli G' (23°C) at 23°C. If they are different, then when the storage modulus G' of the first adhesive layer 5 is G1 (23°C) and the storage modulus G' of the second adhesive layer 6 is G2 (23°C), G2 (23°C) / G1 (23°C) is preferably 0.5 to 0.9, more preferably 0.55 to 0.85. This ensures the above-mentioned effects. In particular, since the first resin layer 2 located on the inner side of the curve tends to peel easily from the polarizing film 4, the storage modulus G' (23°C) of the first adhesive layer 5 bonding them together can be set to a relatively high value, which is effective in preventing this peeling.

[0067] The first adhesive layer 5 and the second adhesive layer 6 may have the same or different storage moduli G'(130°C) at 130°C. If they are different, then when the storage modulus G' of the first adhesive layer 5 is G1(130°C) and the storage modulus G' of the second adhesive layer 6 is G2(130°C), G2(130°C) / G1(130°C) is preferably 0.55 or more and 0.85 or less, and more preferably 0.6 or more and 0.8 or less. This ensures that the above-mentioned effects can be achieved. In particular, since the first resin layer 2 located on the inner side of the curve tends to peel easily from the polarizing film 4, setting the storage modulus G1(130°C) of the first adhesive layer 5 bonding them together to a relatively large value is effective in preventing this peeling during hot bending.

[0068] The optical laminate 10 described above and the eyeglass lens 30 provided with the optical laminate 10 can be manufactured by, for example, applying the following methods for manufacturing an optical laminate and a method for manufacturing an eyeglass lens provided with an optical laminate. Note that the following describes an example in which an optical laminate is manufactured using an extrusion method.

[0069] <Method for producing optical laminate> First, before describing the method for producing an optical laminate, an apparatus for producing an optical laminate will be described.

[0070] Fig. 3 is a side view schematically showing an optical laminate manufacturing apparatus for manufacturing the optical laminate shown in Fig. 2. In the following description, the upper side in Fig. 3 will be referred to as "upper" and the lower side as "lower".

[0071] The optical laminate manufacturing apparatus 1000 shown in FIG. 3 includes a sheet supply unit 200 and a sheet forming unit 300.

[0072] 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.

[0073] The T-die 220 is an extrusion molding section 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 constitutes the optical laminate 10 are sequentially loaded into the T-die 220 in a molten state, and by extruding these molten materials from the T-die 220, the strip-shaped sheet 1' is continuously fed out.

[0074] The sheet forming section 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 this sheet forming section 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 laminate 10 to be loaded into the extruder 210 (T-die 220), the first resin layer 2, the second resin layer 3, and the polarizing film 4 are obtained as the cooled sheet 1'.

[0075] Thereafter, the first resin layer 2 and the polarizing film 4 are bonded via a first adhesive layer 5, and the second resin layer 3 and the polarizing film 4 are bonded via a second adhesive layer 6, thereby obtaining an optical laminate 10.

[0076] The optical laminate 10 is manufactured by the manufacturing method for the optical laminate 10 using the optical laminate manufacturing apparatus 1000 as described above.

[0077] The method for producing the optical laminate 10 using the optical laminate production apparatus 1000 includes an extrusion step, a molding step, a cooling step, an ultraviolet irradiation step, a joining step, and a cutting step.

[0078] <1A> First, a strip-shaped sheet 1' in a molten or softened state is extruded (extrusion step).

[0079] In this extrusion process, the constituent materials of each layer that constitutes the optical laminate 10 are sequentially loaded into the extruder 210. Furthermore, the constituent materials of each layer that constitutes the optical laminate 10 are in a molten or softened state within the extruder 210.

[0080] <2A> Next, the surface of the sheet 1' is flattened, and the sheet 1' is set to a predetermined thickness (forming step). This step is carried out between the touch roll 310 and the cooling roll 320.

[0081] <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.

[0082] The above-described steps <1A> to <3A> can be repeatedly performed by appropriately selecting the constituent materials of each layer that constitutes the optical laminate 10 to be loaded into the extruder 210, thereby obtaining the first resin layer 2, the second resin layer 3, and the polarizing film 4, respectively.

[0083] <4A> The polarizing film 4 is dyed with an aqueous solution of a light absorber ("DB-85") while being stretched in a water tank, then immersed in a boric acid solution, washed with water, and dried. The boric acid solution has a concentration such that the boric acid concentration in the polarizing film 4 is 5.0% by weight or more and 10.0% by weight or less. Specifically, the boric acid concentration in the boric acid solution is approximately 0.30% by weight or more and 1.50% by weight or less.

[0084] <5A> Next, an adhesive for forming the first adhesive layer 5 is applied to the polarizing film 4, and the first resin layer 2 is bonded onto this adhesive, and the adhesive is solidified to form the first adhesive layer 5. In addition, an adhesive for forming the second adhesive layer 6 is applied to the surface of the polarizing film 4 opposite to the first adhesive layer 5, and the second resin layer 3 is bonded onto this adhesive, and the adhesive is solidified to form the second adhesive layer 6 (bonding step). <6A> Next, the obtained laminate is cut to a predetermined length (cutting step).

[0085] As a result, an optical laminate 10 can be obtained in which the first resin layer 2, the second resin layer 3, and the polarizing film 4 are bonded together.

[0086] Through the above steps, the optical laminate 10 is obtained. Next, a method for manufacturing an eyeglass lens, which manufactures an eyeglass lens 30 provided with this optical laminate 10, will be described.

[0087] <Method for manufacturing eyeglass lenses provided with optical laminate> First, before describing the method for manufacturing an eyeglass lens provided with an optical laminate, an eyeglass lens manufacturing apparatus will be described.

[0088] FIG. 4 is a cross-sectional view that schematically shows a spectacle lens manufacturing apparatus that manufactures spectacle lenses provided with an optical laminate.

[0089] The eyeglass lens manufacturing apparatus 400 shown in Fig. 4 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.

[0090] The eyeglass lens 30 provided with the optical laminate 10 is manufactured by the eyeglass lens manufacturing method using the eyeglass lens manufacturing apparatus 400 as described above.

[0091] The method for manufacturing a spectacle lens provided with an optical laminate includes an optical laminate arrangement step and a lens material supply step.

[0092] <1B> First, in a state in which the upper member 630 and the lower member 640 are disassembled, the optical laminate 10 manufactured by the above-described method for manufacturing an optical laminate is placed on the bottom surface 641 of the lower member 640 so that the second resin layer 3 faces the bottom surface 641 (optical laminate 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, since the optical laminate 10 is flexible, it is placed following the shape of the bottom surface 641.

[0093] <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). Then, by cooling the molten or softened lens material, a laminate in which the optical laminate 10 and the eyeglass lens 30 are stacked, i.e., an eyeglass lens 30 to which the optical laminate 10 is attached, can be obtained.

[0094] Although the so-called sheet insert method has been described above as an example, the eyeglass lens 30 provided with the optical laminate 10 is not limited to this, and may be configured, for example, such that the optical laminate 10 is laminated onto a molded eyeglass lens 30 via an adhesive layer.

[0095] 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.

[0096] For example, each part constituting the optical laminate of the present invention can be replaced with any part having an arbitrary configuration that can exert the same function.

[0097] In addition to the above-mentioned components, the optical layered body of the present invention may further include any other components.

[0098] More specifically, for example, the optical layered body of the present invention may include an intermediate layer, a power adjusting layer for adjusting the power of the lens, and the like.

[0099] Furthermore, the optical laminate of the present invention is not limited to being attached to the eyeglass lenses described in the above embodiment, but can also be used for optical components that are attached to, for example, 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]

[0100] The present invention will be described in more detail below based on examples. 1. Preparation of optical laminate [Example 1] [1] First, a polyvinyl alcohol film (Kuraray Co., Ltd.'s "Kuraray Vinylon #7500") was stretched in a water tank while being dyed with an aqueous solution of light absorber ZX ("DB-85"), and then immersed in a boric acid solution, followed by washing with water and drying to obtain polarizing film 4. The boric acid content was measured by titrating a test solution prepared by heating and dissolving polarizing film 4 in water using the neutralization titration method.

[0101] [2] Next, 100 parts by weight of bisphenol A polycarbonate (manufactured by Mitsubishi Engineering-Plastics Corporation, "Iupilon E2000FN E5100") was prepared as a resin layer-forming material, and the resin layer-forming material was placed in the extruder 210 of the optical laminate manufacturing apparatus 1000 shown in Fig. 5, melted, and extruded through a T-die 220 to obtain a first resin layer 2. In the same manner, a second resin layer 3 was obtained.

[0102] [3] Next, a coating film consisting of a base agent: "Takelac A-1143" manufactured by Mitsui Chemicals, Inc. and a curing agent: "Takenate A-50" manufactured by Mitsui Chemicals, Inc. was applied to both sides of the polarizing film 4 so that the thickness of the adhesive layer formed after solidification would be 20 μm. In addition, a first resin layer 2 was attached to one side of the laminate in which the coating film was laminated on the polarizing film 4, and a second resin layer 3 was attached to the other side, and then the coating film was solidified to obtain an optical laminate 10.

[0103] The storage modulus G'(23°C) of the first adhesive layer 5 and the second adhesive layer 6 was the same, 14.3 MPa. The storage modulus G'(130°C) of the first adhesive layer 5 and the second adhesive layer 6 was the same, 0.9 MPa. G'(23°C) / G'(130°C) was 15.9.

[0104] The storage modulus G' (23°C) of the first adhesive layer 5 and the second adhesive layer 6 was measured in accordance with JIS K7244-4 using adhesive layers 16 and 17 measuring 4 mm in width and 20 mm in length, using a dynamic viscoelasticity measuring device (manufactured by SII NanoTechnology, Inc., "DMS6100") The measurement conditions were tensile mode, frequency 1 Hz, heating rate 5°C / min, and temperature 23°C.

[0105] The storage modulus G' (130°C) of the first adhesive layer 5 and the second adhesive layer 6 was measured in accordance with JIS K7244-4 using a dynamic viscoelasticity measuring device ("DMS6100" manufactured by SII NanoTechnology Inc.) with adhesive layers 16 and 17 measuring 4 mm in width and 20 mm in length. The measurement conditions were tensile mode, frequency 1 Hz, heating rate 5°C / min, and temperature 130°C.

[0106] Next, this optical laminate 10 was punched out to a diameter of 8 cm, and then subjected to hot bending processing while suctioning at 150°C for 10 minutes using a Rema molding machine (vacuum molding machine) (CR-32 type), thereby obtaining the optical laminate 10 of Example 1.

[0107] [Examples 2 to 4, Comparative Example 1] The optical laminates of Examples 2 to 4 and Comparative Example 1 were obtained in the same manner as in Example 1, except that the boric acid concentration in the polarizing film 4, and the types and contents of the first adhesive layer 5 and the second adhesive layer 6 were changed as shown in Table 1.

[0108] 3. Evaluation of optical laminates The optical laminates of the examples and comparative examples were evaluated by the following methods.

[0109] (Light leakage) Twenty of the prepared optical laminates were placed on a backlight equipped with a polarizer, and the appearance was observed using transmitted light in both crossed Nicols and parallel Nicols states to check whether streaky light leakage had occurred, and the results were evaluated as follows.

[0110] ◎: No streaky light leakage was observed ◯: Streaky light leakage was observed, but was at a level that did not pose a problem in practical use. ×: Numerous streaky light leakage was observed, and the polarizing film was damaged.

[0111] (Indentation marks at room temperature) The optical laminates 10 of the examples and comparative examples were evaluated for their ability to leave indentation marks at room temperature by the following method.

[0112] First, a test specimen was prepared by stacking cushion paper, the optical laminate 10, and a 20 mm square, 2 mm thick polycarbonate plate in this order. The test specimen was then placed in a press and subjected to a press test at pressures of 1 MPa and 5 MPa for 30 seconds each. The surface of the optical laminate 10 after the test (the surface in contact with the polycarbonate plate) was then visually observed. The observation results were then evaluated for indentation at room temperature according to the following evaluation criteria.

[0113] ◎: No marks are left even when pressed with 5 MPa ○: No marks are left even when pressed at 1 MPa ×: Marks are left when pressed at 1 MPa

[0114] (heat bending formability) The optical laminate 10 of each example and comparative example was visually observed to calculate the ratio of peeled area per unit area of ​​the optical laminate 10. The calculated results were then used to evaluate the heat bending formability of the optical laminate 10 in accordance with the following evaluation criteria.

[0115] ◎: The ratio of peeled area is 0% (no peeling) ○: The ratio of peeled area is more than 0% and 5% or less ×: The ratio of peeled area is more than 5%

[0116] (End melts when emitted) The optical laminate of each example was adsorbed onto a mold having a curved concave surface, and then a resin layer composed of an optical resin for injection molding (polycarbonate-based resin, manufactured by Mitsubishi Gas Chemical Company, Inc., "H-3000") was injection molded onto the curved concave surface of the optical laminate using an insert injection molding method at 150°C. This resulted in a spectacle lens 30 comprising the optical laminate and a resin layer composed of a polycarbonate-based resin. The edges of the optical laminate were then visually observed for the presence or absence of molten adhesive layers 5, 6, i.e., the presence or absence of edge melting during injection. The observation results were then evaluated for edge melting during injection in light of the following evaluation criteria.

[0117] ◎: No edge melting was observed ○: Melting of the edge was observed, but it was at a level that did not pose a problem in practical use. ×: Melting of the edge occurred, and a defect in appearance occurred.

[0118] The evaluation results of the optical laminates of the Examples and Comparative Examples obtained as described above are shown in Table 1 below.

[0119] [Table 1]

[0120] As shown in Table 1, in the optical laminate of each example, the optical laminate 10 satisfies the following requirements A and B, thereby preventing damage to the polarizing film 4 during thermal bending processing while preventing partial peeling of the first resin layer 2 or the second resin layer 3 from the polarizing film 4.

[0121] Requirement A: The polarizing film 4 contains boric acid, and the concentration (hereinafter referred to as "boric acid concentration") is 5.0% by weight or more and 10.0% by weight or less. Requirement B: The first adhesive layer 5 and the second adhesive layer 6 each have a storage modulus G' (23°C) at 23°C of 3.0 MPa or more and 200.0 MPa or less.

[0122] In contrast, the optical laminate in the comparative example did not satisfy the above requirements A and B, and as a result, damage to the polarizing film 4 was confirmed during the thermal bending process, and partial peeling of the first resin layer 2 or the second resin layer 3 from the polarizing film 4 was confirmed. [Explanation of symbols]

[0123] 1' sheet 2 First resin layer 3 Second resin layer 4. Polarizing film 5 First adhesive layer 6 Second adhesive layer 10 Optical laminate 20 frames 30 Eyeglass lenses 41 Rim 42 Bridge section 43 Temple 44 Nose pad section 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 laminate manufacturing equipment

Claims

1. A polarizing film; a first resin layer provided on one surface of the polarizing film and containing mainly polycarbonate; a second resin layer provided on the other surface of the polarizing film and containing mainly polycarbonate; a first adhesive layer provided between the polarizing film and the first resin layer to bond them together; a second adhesive layer provided between the polarizing film and the second resin layer to bond them together, the polarizing film contains boric acid at a concentration of 5.0% by weight or more and 10.0% by weight or less; The optical laminate, wherein the first adhesive layer and the second adhesive layer each have a storage modulus G' (23°C) at 23°C of 3.0 MPa or more and 200.0 MPa or less.

2. 2. The optical laminate according to claim 1, wherein the first adhesive layer and the second adhesive layer each have a storage modulus G'(130°C) at 130°C of 0.5 MPa or more and 15.0 MPa or less.

3. 3. The optical laminate according to claim 2, wherein G'(23°C) / G'(130°C) is 5 or more and 30 or less.

4. The optical laminate according to claim 1 , wherein the first adhesive layer and the second adhesive layer contain polyurethane.

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