Optical laminate, method for producing optical laminate, and optical information transmission device

Abstract

An optical laminate (10) comprises an optical substrate (1), a (thio)urethane-based optical resin layer α on one surface α side of the optical substrate (1), and a (thio)urethane-based optical resin layer β on a surface β side on the opposite side of the optical substrate from the surface α.

Description

Optical laminate, method for manufacturing optical laminate, and optical information transmission device

[0001] The present invention relates to an optical laminate, a method for manufacturing an optical laminate, and an optical information transmission device.

[0002] In recent years, there has been an increasing demand for resin materials in the field of optical devices due to reasons such as weight reduction and improved impact resistance. For example, the use of resin materials is required in optical devices that are worn on the human body when used, such as wearable devices.

[0003] Patent Document 1 discloses a light-weight optical element that contains an organic polymer and has an area of ​​1 mm ２ or more, and the area is 1 mm ２ The document discloses an optical member including a surface A, the flatness of which is measured by a non-contact optical flatness meter and is 80 μm or less.

[0004] International Publication No. 2020 / 170801

[0005] The present invention provides an optical laminate comprising an optical substrate and a (thio)urethane-based optical resin layer, which can suppress warping.

[0006] That is, according to the present invention, there are provided the following optical laminate, a method for manufacturing an optical laminate, and an optical information transmission device. 1. An optical laminate comprising: an optical substrate; a (thio)urethane-based optical resin layer α on one surface α of the optical substrate; and a (thio)urethane-based optical resin layer β on a surface β of the optical substrate opposite to surface α. 2. The optical laminate according to 1., wherein the (thio)urethane-based optical resin layer α and the (thio)urethane-based optical resin layer β each have a thickness of 2.0 mm or less. 3. The optical laminate according to 1. or 2., wherein the (thio)urethane-based optical resin layer α and the (thio)urethane-based optical resin layer β each have a refractive index of 1.47 or more at a temperature of 25°C and a wavelength of 587.6 nm in accordance with JIS K-0062:1992. 4. The optical laminate according to any one of 1. to 3., wherein the optical substrate has a refractive index of 1.47 or more at a temperature of 25°C and a wavelength of 587.6 nm in accordance with JIS K-0062:1992. 5. The optical laminate according to any one of 1. to 4., wherein the optical substrate comprises one or more substrates selected from the group consisting of glass substrates and optical crystal substrates. 6. The optical laminate according to any one of 1. to 5., further comprising: an adhesive layer α between the optical substrate and the (thio)urethane-based optical resin layer α; and an adhesive layer β between the optical substrate and the (thio)urethane-based optical resin layer β. 7. The optical laminate according to 6., wherein the adhesive layer α and the adhesive layer β each have a thickness of 0.5 μm or more and 1000 μm or less. 8. The optical laminate according to 6. or 7., further comprising a transparent inorganic layer at least either between the optical substrate and the adhesive layer α or between the optical substrate and the adhesive layer β. 9. 10. The optical laminate according to any one of 6. to 8., further comprising a coupling agent layer at least one between the optical substrate and the adhesive layer α and between the optical substrate and the adhesive layer β. 10. The amount of warpage F of the surface A on the side of the (thio)urethane-based optical resin layer α after leaving the optical laminate at 50°C for 30 minutes Ａ11. The optical laminate according to any one of 1. to 9., wherein the warpage F of the surface A on the (thio)urethane-based optical resin layer α side of the optical laminate is measured using a non-contact optical flatness meter after the optical laminate is left standing for 360 hours in an environment of a temperature of 60°C and a humidity of 90%. ＡThe optical laminate according to any one of 1. to 10., wherein the refractive index of the optical laminate is 1.47 or more at a temperature of 25°C and a wavelength of 587.6 nm in accordance with JIS K-0062:1992. 13. The optical laminate according to any one of 1. to 12., which can be used in a wearable device. 14. 15. A method for producing an optical laminate, comprising: step (A) of preparing a laminate X comprising an optical substrate, a (thio)urethane-based optical resin layer α on one surface α of the optical substrate, an uncured or semi-cured adhesive layer α between the optical substrate and the (thio)urethane-based optical resin layer α, a (thio)urethane-based optical resin layer β on a surface β of the optical substrate opposite to surface α, and an uncured or semi-cured adhesive layer β between the optical substrate and the (thio)urethane-based optical resin layer β, and step (B) of simultaneously curing the uncured or semi-cured adhesive layer α and the uncured or semi-cured adhesive layer β to obtain an optical laminate. 16. The method for producing an optical laminate according to item 14, further comprising step (C) of placing the laminate X in a reduced pressure environment before step (B). 17. A method for producing an optical laminate, comprising: step (D) of preparing a laminate Y including an optical substrate, a (thio)urethane-based optical resin layer α on one surface α of the optical substrate, and an uncured or semi-cured adhesive layer α between the optical substrate and the (thio)urethane-based optical resin layer α; step (E) of curing the uncured or semi-cured adhesive layer α to obtain a cured laminate Y; step (F) of preparing a laminate Z including the cured laminate Y, a (thio)urethane-based optical resin layer β on the surface β side of the cured laminate Y facing the optical substrate, and an uncured or semi-cured adhesive layer β between the cured laminate Y and the (thio)urethane-based optical resin layer β; and step (G) of curing the uncured or semi-cured adhesive layer β to obtain an optical laminate. 17. The method for producing an optical laminate according to 16., further comprising step (H) of placing the laminate Y in a reduced pressure environment before step (E). 18. 18. The method for producing an optical laminate according to 16. or 17., further comprising a step (I) of placing the laminate Z in a reduced pressure environment before the step (G).19. The optical laminate further comprises a step (J) of annealing the optical laminate, wherein the glass transition temperatures of the adhesive layers α and β are T. １ When the annealing temperature T ２ But (T １ +5)℃ or higher (T １ 20. The method for producing an optical laminate according to any one of 14. to 18., wherein the annealing temperature T ２ 19. The method for producing the optical laminate according to 19., wherein the temperature is 60° C. or higher. 21. An optical information transmission device comprising: a light irradiation unit; and the optical laminate according to any one of 1. to 13.

[0007] According to the present invention, it is possible to provide an optical laminate comprising an optical substrate and a (thio)urethane-based optical resin layer, which can suppress warping.

[0008] 1 is a cross-sectional view schematically showing an example of an optical laminate according to an embodiment of the present invention; 2 is a cross-sectional view schematically showing an example of an optical information transmission device according to an embodiment of the present invention;

[0009] The present invention will be described below based on the embodiments. When numerical ranges are described in stages, the upper and lower limits of each numerical range can be combined in any way.

[0010] [Optical Laminate] The optical laminate of this embodiment will be described in detail below.

[0011] The optical laminate of this embodiment will be described with reference to Fig. 1. The optical laminate 10 of this embodiment includes an optical substrate 1, a (thio)urethane-based optical resin layer α (2) on one surface α of the optical substrate 1, and a (thio)urethane-based optical resin layer β (3) on a surface β of the optical substrate 1 opposite to the surface α.

[0012] Although the mechanism by which the optical laminate of this embodiment solves the above-mentioned problems is not clear, it is speculated that the above-mentioned problems are solved by the following mechanism. First, as a premise, due to the difference in linear expansion coefficient between the optical substrate and the (thio)urethane-based optical resin layer, distortion is likely to occur in the optical laminate, which is likely to cause warping. It is speculated that in the optical laminate of this embodiment, sandwiching the optical substrate between the (thio)urethane-based optical resin layers contributes to suppressing warping.

[0013] <(Thio)urethane-Based Optical Resin Layer> Hereinafter, the (thio)urethane-based optical resin layer of the optical laminate of this embodiment will be described.

[0014] The (thio)urethane-based optical resin layer contains a (thio)urethane-based resin. The (thio)urethane-based resin can be obtained from an iso(thio)cyanate compound and a bifunctional or higher functional active hydrogen compound. Examples of the bifunctional or higher functional active hydrogen compound include a polyol compound and a polythiol compound.

[0015] Examples of the iso(thio)cyanate compound include hexamethylene diisocyanate, pentamethylene diisocyanate, xylylene diisocyanate, isophorone diisocyanate, bis(isocyanatomethyl)cyclohexane, bis(isocyanatocyclohexyl)methane, 2,5-bis(isocyanatomethyl)bicyclo-[2.2.1]-heptane, 2,6-bis(isocyanatomethyl)bicyclo-[2.2.1]-heptane, tolylene diisocyanate, phenylene diisocyanate, and 4,4'-diphenylmethane diisocyanate.

[0016] Examples of polythiol compounds include pentaerythritol tetrakis(2-mercaptoacetate), pentaerythritol tetrakis(3-mercaptopropionate), bis(2-mercaptoethyl) sulfide, 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane, 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4,7-dimercaptomethyl-1,11-dimercapto-3,6, 9-trithiaundecane, 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 2,5-dimercaptomethyl-1,4-dithiane, 1,1,3,3-tetrakis(mercaptomethylthio)propane, 4,6-bis(mercaptomethylthio)-1,3-dithiane, 2-(2,2-bis(mercaptomethylthio)ethyl)-1,3-dithietane, ethylene glycol bis(3-mercaptopropionate), and the like.

[0017] Examples of polyol compounds include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 3-methyl-1,3-butanediol, 1,2-pentanediol, 1,3-pentanediol, 1,5-pentanediol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 3-methyl linear or branched aliphatic alcohols such as 1,5-pentanediol, 1,6-hexanediol, 2,5-hexanediol, glycerol, diglycerol, polyglycerol, trimethylolpropane, pentaerythritol, and di(trimethylolpropane); and alicyclic alcohols such as 1,2-cyclopentanediol, 1,3-cyclopentanediol, 3-methyl-1,2-cyclopentanediol, 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 4,4'-bicyclohexanol, and 1,4-cyclohexanedimethanol.

[0018] The thickness of the (thio)urethane-based optical resin layer α and the (thio)urethane-based optical resin layer β is preferably 2.0 mm or less, more preferably 1.5 mm or less, even more preferably 1.0 mm or less, even more preferably 0.8 mm or less, even more preferably 0.6 mm or less, and even more preferably 0.4 mm or less.

[0019] From the viewpoint of improving the optical properties of the optical laminate, the refractive index of the (thio)urethane-based optical resin layer α and the (thio)urethane-based optical resin layer β at a temperature of 25°C and a wavelength of 587.6 nm in accordance with JIS K-0062:1992 is preferably 1.47 or more, more preferably 1.49 or more, even more preferably 1.51 or more, and still more preferably 1.53 or more, and may be, for example, 1.90 or less, 1.80 or less, or 1.70 or less.

[0020] The linear expansion coefficient of the (thio)urethane-based optical resin layer α and the (thio)urethane-based optical resin layer β measured under the following <Measurement Conditions> is preferably 100×10 from the viewpoint of further suppressing warping of the optical laminate and suppressing peeling of the optical laminate. －６ / °C or less, more preferably 80 x 10 －６ / °C or less, and from the viewpoint of further suppressing warping of the optical laminate and suppressing peeling of the optical laminate, it is better that the difference in linear expansion coefficient between the optical laminate and the optical substrate is small. Therefore, it is preferably 2 × 10 －６ / °C or more, more preferably 4 x 10 －６ / °C or more, more preferably 6 × 10 －６ / °C or more, more preferably 8 × 10 －６ / °C or more. <Measurement conditions> Measurement mode: TMA compression mode Test load: 50 mN Heating rate: 5°C / min Test temperature range: 23 to 200°C Measurement atmosphere: nitrogen (100 ml / min)

[0021] <Optical Substrate> Hereinafter, the optical substrate of the optical laminate of this embodiment will be described.

[0022] The refractive index of the optical substrate at a temperature of 25°C and a wavelength of 587.6 nm according to JIS K-0062:1992 is, from the viewpoint of improving the optical properties of the optical laminate, preferably 1.47 or more, more preferably 1.49 or more, even more preferably 1.51 or more, and still more preferably 1.53 or more, and may be, for example, 1.90 or less, 1.80 or less, or 1.70 or less.

[0023] The optical substrate preferably includes one or more types selected from the group consisting of a glass substrate and an optical crystal substrate. Examples of the optical crystal substrate include a SiC substrate, a LiNb ２ O ３ Substrate (LN substrate), Al ２ O ３ Examples of the substrate include a sapphire substrate, a crystal substrate, and a quartz substrate.

[0024] The linear expansion coefficient of the optical substrate measured under the following <Measurement Conditions> is preferably 0.1 × 10 because the difference in linear expansion coefficient between the adhesive layer and the (thio)urethane-based optical resin layer is preferably small from the viewpoint of further suppressing warping of the optical laminate and suppressing peeling of the optical laminate. －６ / °C or more, more preferably 0.5 × 10 －６ / °C or more, more preferably 2 × 10 －６ / °C or more, more preferably 4 x 10 －６ / °C or more, and for example, 40 x 10 －６ / °C or less, and －６ / °C or less. <Measurement conditions> Measurement mode: TMA compression mode Test load: 50 mN Heating rate: 5°C / min Test temperature range: 23 to 200°C Measurement atmosphere: nitrogen (100 ml / min)

[0025] <Other Layer Configurations> The optical laminate of this embodiment may have configurations other than the (thio)urethane-based optical resin layer α, the (thio)urethane-based optical resin layer β, and the optical substrate.

[0026] From the viewpoint of further suppressing warping of the optical laminate and suppressing peeling of the optical laminate, the optical laminate of this embodiment preferably further comprises an adhesive layer α between the optical substrate and the (thio)urethane-based optical resin layer α, and an adhesive layer β between the optical substrate and the (thio)urethane-based optical resin layer β.

[0027] From the viewpoint of further suppressing warping of the optical laminate and from the viewpoint of suppressing peeling of the optical laminate, the thicknesses of the adhesive layer α and the adhesive layer β are each preferably 0.5 μm or more, more preferably 1 μm or more, even more preferably 5 μm or more, even more preferably 10 μm or more, and even more preferably 15 μm or more, and from the viewpoint of reducing the overall thickness of the optical laminate, the thicknesses of the adhesive layer α and the adhesive layer β are each preferably 1000 μm or less, more preferably 500 μm or less, even more preferably 200 μm or less, even more preferably 100 μm or less, even more preferably 80 μm or less, and even more preferably 60 μm or less.

[0028] From the viewpoint of further suppressing warping of the optical laminate, suppressing peeling of the optical laminate, and reducing the overall thickness of the optical laminate, the thicknesses of the adhesive layer α and the adhesive layer β are each preferably 0.5 μm or more and 1000 μm or less, more preferably 1 μm or more and 500 μm or less, even more preferably 5 μm or more and 200 μm or less, even more preferably 10 μm or more and 100 μm or less, even more preferably 15 μm or more and 80 μm or less, and even more preferably 15 μm or more and 60 μm or less.

[0029] The glass transition temperatures of the adhesive layer α and the adhesive layer β are, from the viewpoint of further suppressing warping of the optical laminate and suppressing peeling of the optical laminate, preferably 70°C or lower, more preferably 65°C or lower, even more preferably 60°C or lower, even more preferably 55°C or lower, even more preferably 50°C or lower, and even more preferably 45°C or lower, respectively; and, from the viewpoint of further suppressing warping of the optical laminate and suppressing peeling of the optical laminate in a high temperature environment and / or a high humidity environment, are preferably -20°C or higher, more preferably -10°C or higher, even more preferably 0°C or higher, even more preferably 10°C or higher, even more preferably 15°C or higher, and even more preferably 20°C or higher, respectively.

[0030] The glass transition temperatures of the adhesive layer α and the adhesive layer β can be measured by dynamic viscoelasticity measurement (DMA). Specifically, they can be measured under the following <measurement conditions>. <Measurement conditions> Apparatus: Dynamic viscoelasticity measuring apparatus Sample shape: Width 10 mm × Thickness 0.1 mm × Length 20 mm Heating rate: 5°C / min Measurement mode: Tension

[0031] The glass transition temperatures of the adhesive layers α and β can be adjusted by adjusting the composition of the adhesive layers, for example, by adjusting the ratio of high-molecular-weight components to low-molecular-weight components in the adhesive layers or by adjusting the crosslink density of the adhesive layers.

[0032] The loss modulus of the adhesive layer α and the adhesive layer β, measured in tension at a temperature of 25°C and a measurement frequency of 1 Hz, is preferably 0.001 GPa or more, more preferably 0.01 GPa or more, and even more preferably 0.03 GPa or more, from the viewpoint of further suppressing warping of the optical laminate and suppressing peeling of the optical laminate, and is preferably 1.5 GPa or less, more preferably 1.3 GPa or less, even more preferably 1.1 GPa or less, even more preferably 0.9 GPa or less, even more preferably 0.7 GPa or less, even more preferably 0.5 GPa or less, and even more preferably 0.3 GPa or less, from the viewpoint of further suppressing warping of the optical laminate and suppressing peeling of the optical laminate.

[0033] The loss modulus of the adhesive layer α and the adhesive layer β can be measured by dynamic mechanical analysis (DMA). Specifically, the measurement can be performed under the following <measurement conditions>. <Measurement conditions> Apparatus: Dynamic mechanical analysis apparatus Sample shape: Width 10 mm × Thickness 0.1 mm × Length 20 mm Temperature: 25°C Measurement mode: Tension

[0034] The loss modulus of the adhesive layer α and the adhesive layer β can be adjusted by adjusting the composition of the adhesive layer, for example, by adjusting the ratio of high molecular weight components to low molecular weight components in the adhesive layer or by adjusting the crosslink density of the adhesive layer.

[0035] The adhesive layer α and the adhesive layer β preferably contain one or more resins selected from the group consisting of (meth)acrylic resins and epoxy resins, and more preferably contain a (meth)acrylic resin.

[0036] The adhesive layer α and the adhesive layer β may further contain a known adhesive. Examples of known adhesives include laminating adhesives composed of organic titanium resins, polyethyleneimine resins, urethane resins, polyester resins, oxazoline group-containing resins, modified silicone resins, alkyl titanates, polyester polybutadienes, etc., as well as one-component and two-component polyols and polyisocyanates, water-based urethanes, ionomers, etc. Alternatively, aqueous adhesives whose main raw materials are acrylic resins, vinyl acetate resins, urethane resins, polyester resins, etc. may be used. Furthermore, other additives such as curing agents and silane coupling agents may be added to the adhesive depending on the application of the gas barrier laminate.

[0037] From the viewpoint of suppressing peeling of the optical laminate of this embodiment, the optical laminate preferably further includes a transparent inorganic layer between the optical substrate and the adhesive layer α and / or between the optical substrate and the adhesive layer β. The means for forming the transparent inorganic layer is not particularly limited, but it can be formed, for example, by sputtering the surface of the optical substrate. Specifically, the optical substrate is first placed in a vacuum chamber, a gas such as argon gas is introduced, and then a negative voltage is applied to the surface of the optical substrate to generate a glow discharge and ionize the gas atoms. This causes the ionized gas atoms to collide with the surface of the optical substrate, ejecting particles (atoms and molecules) from the surface of the optical substrate and adhering and depositing on the surface of the optical substrate, thereby forming a transparent inorganic layer.

[0038] The thickness of the transparent inorganic layer is not particularly limited, but from the viewpoint of further suppressing warping of the optical laminate and suppressing peeling of the optical laminate, it is preferably 5 nm or more, more preferably 10 nm or more, even more preferably 20 nm or more, and still more preferably 50 nm or more, and may be, for example, 100 nm or less.

[0039] From the viewpoint of suppressing peeling of the optical laminate, the optical laminate of this embodiment preferably further comprises a coupling agent layer at least either between the optical substrate and the adhesive layer α or between the optical substrate and the adhesive layer β.

[0040] The coupling agent contained in the coupling agent layer is not particularly limited, and examples thereof include silane coupling agents. Examples of the silane coupling agent include vinyl group-containing silane coupling agents such as vinyltrimethoxysilane and vinyltriethoxysilane, epoxy group-containing silane coupling agents such as 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane and 3-glycidoxypropyltriethoxysilane, and (meth)acrylic group-containing silane coupling agents such as 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane and 3-acryloxypropyltrimethoxysilane.

[0041] The thickness of the coupling agent layer is not particularly limited, but from the viewpoint of further suppressing warping of the optical laminate and suppressing peeling of the optical laminate, it is preferably 1 nm or more, more preferably 2 nm or more, even more preferably 5 nm or more, and even more preferably 10 nm or more, and may be, for example, 50 nm or less.

[0042] In addition to the configuration described above, the optical laminate of this embodiment may also have layer configurations such as an antistatic layer that prevents the optical laminate from becoming charged, a hard coat layer that prevents the optical laminate from being scratched, a moisture-blocking layer that blocks moisture from penetrating into the optical laminate, and an antireflection film that reduces surface reflection of the optical laminate.

[0043] <Physical Properties and Applications of Optical Laminate> Hereinafter, the physical properties and applications of the optical laminate of this embodiment will be described.

[0044] The amount of warpage F of the surface A on the (thio)urethane-based optical resin layer α side of the optical laminate of this embodiment after being left standing at 50° C. for 30 minutes Ａ is preferably 200 μm or less, more preferably 150 μm or less, even more preferably 100 μm or less, and even more preferably 50 μm or less, and may be, for example, 0.01 μm or more.

[0045] Amount of warpage F Ａ can be measured using an ultra-high precision three-dimensional measuring machine. Specifically, the measurement can be performed under the following conditions: Apparatus: UA3P (manufactured by Panasonic Production Engineering Co., Ltd.) Measurement area: a circular area of ​​±30 mm in the X and Y directions from the center of the optical laminate.

[0046] The optical laminate of this embodiment is left standing for 360 hours in an environment of a temperature of 60°C and a humidity of 90%, and then the surface A on the side of the (thio)urethane-based optical resin layer α of the optical laminate is measured with a non-contact optical flatness meter to obtain the warpage F of the surface A. Ａ is preferably 350 μm or less, more preferably 300 μm or less, even more preferably 250 μm or less, even more preferably 200 μm or less, even more preferably 150 μm or less, even more preferably 100 μm or less, even more preferably 50 μm or less, and may be, for example, 0.01 μm or more.

[0047] The refractive index of the optical laminate at a temperature of 25°C and a wavelength of 587.6 nm according to JIS K-0062:1992 is, from the viewpoint of improving the optical properties of the optical laminate, preferably 1.47 or more, more preferably 1.49 or more, even more preferably 1.51 or more, and still more preferably 1.53 or more, and may be, for example, 1.90 or less, 1.80 or less, or 1.70 or less.

[0048] The use of the optical laminate of the present embodiment is not particularly limited, but it can be used in wearable devices, and more specifically, it can be used in wearable displays that display virtual reality (VR), augmented reality (AR), and the like.

[0049] [Method for manufacturing optical laminate] Hereinafter, a method for manufacturing the optical laminate of this embodiment will be described. The method for manufacturing the optical laminate of this embodiment can be roughly divided into a method in which an optical substrate, a (thio)urethane-based optical resin layer α, and a (thio)urethane-based optical resin layer β are all laminated together and then cured (simultaneous curing), and a method in which an optical substrate and a (thio)urethane-based optical resin layer α are laminated together, cured, and then a urethane-based optical resin layer β is laminated together and then cured (sequential curing).

[0050] <Simultaneous Curing> Simultaneous curing will now be described.

[0051] The method for producing an optical laminate of this embodiment includes the steps of: (A) preparing a laminate X including an optical substrate; a (thio)urethane-based optical resin layer α on one surface α of the optical substrate; an uncured or semi-cured adhesive layer α between the optical substrate and the (thio)urethane-based optical resin layer α; a (thio)urethane-based optical resin layer β on a surface β of the optical substrate opposite to surface α; and an uncured or semi-cured adhesive layer β between the optical substrate and the (thio)urethane-based optical resin layer β; and (B) simultaneously curing the uncured or semi-cured adhesive layer α and the uncured or semi-cured adhesive layer β to obtain the optical laminate.

[0052] The method for producing an optical laminate of this embodiment may further include a step (C) of placing the laminate X in a reduced pressure environment before the step (B). This can prevent misalignment of the components during lamination. This can also prevent air bubbles from forming between the layers.

[0053] <Sequential Curing> Sequential curing will now be described.

[0054] The method for producing the optical laminate of this embodiment includes the steps of: (D) preparing a laminate Y including an optical substrate, a (thio)urethane-based optical resin layer α on one surface α of the optical substrate, and an uncured or semi-cured adhesive layer α between the optical substrate and the (thio)urethane-based optical resin layer α; (E) curing the uncured or semi-cured adhesive layer α to obtain a cured laminate Y; (F) preparing a laminate Z including the cured laminate Y, a (thio)urethane-based optical resin layer β on the surface β of the cured laminate Y facing the optical substrate, and an uncured or semi-cured adhesive layer β between the cured laminate Y and the (thio)urethane-based optical resin layer β; and (G) curing the uncured or semi-cured adhesive layer β to obtain the optical laminate.

[0055] The method for producing an optical laminate of this embodiment may further include a step (H) of placing the laminate Y in a reduced pressure environment before the step (E). This can prevent misalignment of the components during lamination. This can also prevent air bubbles from being generated between layers.

[0056] The method for producing an optical laminate of this embodiment may further include a step (I) of placing the laminate Z in a reduced pressure environment before the step (G). This can prevent misalignment of the components during lamination. This can also prevent air bubbles from forming between the layers.

[0057] <Other Steps> The method for producing an optical laminate of this embodiment may include steps other than the steps described above.

[0058] The method for producing an optical laminate of this embodiment may further include a step (J) of annealing the optical laminate. １ When the annealing temperature T ２ is preferably (T １ +5) ° C. or higher, more preferably (T １ +10) ° C. or higher, and preferably (T １ +20) ° C. or less, more preferably (T １ +15° C. or lower. This makes it possible to further suppress warping of the optical laminate.

[0059] The glass transition temperatures of the adhesive layers α and β are defined as T １ When the annealing temperature T ２ is preferably (T １ +5)℃ or higher (T １ +20) ° C. or less, more preferably (T １ +10)℃ or higher (T １ +15° C. or lower. This makes it possible to further suppress warping of the optical laminate.

[0060] The annealing temperature is preferably 60° C. or higher, more preferably 70° C. or higher, even more preferably 80° C. or higher, even more preferably 90° C. or higher, and even more preferably 100° C. or higher, and may be, for example, 200° C. or lower, thereby further suppressing warping of the optical laminate.

[0061] The method for producing an optical laminate of this embodiment may further include a step of sputtering the surface of the optical substrate. By sputtering the surface of the optical substrate, a transparent inorganic layer can be formed on the surface of the optical substrate.

[0062] The method for producing an optical laminate of this embodiment may further include a step of performing surface treatment plasma ashing on the surface of the optical substrate. By performing plasma ashing on the surface of the optical substrate, the surface of the optical substrate can be activated.

[0063] The method for producing an optical laminate of this embodiment may further include a step of applying a coupling agent to the surface of the optical substrate. By applying the coupling agent to the surface of the optical substrate, a coupling agent layer can be formed on the surface of the optical substrate.

[0064] In the manufacturing method of the optical laminate of this embodiment, it is preferable to apply a coupling agent to the sputtered surface of the optical substrate from the viewpoint of further suppressing warping of the optical laminate and suppressing peeling of the optical laminate.

[0065] [Optical Information Transmission Device] Hereinafter, an optical information transmission device according to this embodiment will be described.

[0066] The optical information transmission device of this embodiment will be described with reference to Fig. 2. The optical information transmission device 20 of this embodiment includes a light irradiation unit 11 and the optical laminate 10 described above.

[0067] Light 12 emitted from the light emitting unit 11 is reflected by the optical laminate 10, and the reflected light is irradiated onto the user's eye 13. As a result, the light emitted from the light emitting unit 11 is recognized by the user wearing the optical information transmission device 10.

[0068] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various other configurations may be adopted. Furthermore, the present invention is not limited to the above-described embodiments, and modifications and improvements within the scope of achieving the object of the present invention are included in the present invention.

[0069] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to the following examples as long as it does not depart from the gist of the invention.

[0070] <Preparation of Optical Laminate> The following materials were prepared: Glass substrate (1) (manufactured by Corning Incorporated, diameter 80 mm, thickness 0.5 mm, refractive index 1.51, linear expansion coefficient 31.7 × 10 ―７ / °C) Thiourethane-based optical resin sheet α(1) (manufactured by Mitsui Chemicals, Inc., product name SK-600, diameter 78 mm, thickness 0.35 mm, refractive index 1.67, linear expansion coefficient 6.5×10 ―５ / °C) Thiourethane-based optical resin sheet β(1) (manufactured by Mitsui Chemicals, Inc., product name SK-600, diameter 78 mm, thickness 0.35 mm, refractive index 1.67, linear expansion coefficient 6.5 × 10 ―５ / °C) Adhesive resin composition (A) (acrylic, ultraviolet curable) Adhesive resin composition (C) (acrylic, ultraviolet curable)

[0071] (Examples 1 and 3) (Double-sided application, simultaneous curing) A glass substrate (1) was sputtered to form a transparent inorganic layer α on the surface of the glass substrate (1). Metallic Si was used as the sputtering target. Ar and O were used as the carrier gas. ２The sputtering power was 5.5 kW. The method for forming the transparent inorganic layer is not particularly limited, and the layer may be formed by ion-assisted deposition. Next, a silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., product name KBM-5103) was applied to the transparent inorganic layer α of the glass substrate (1) to form a silane coupling agent layer α with a thickness of 7 nm. Next, an adhesive resin composition shown in Table 1 was applied to the silane coupling agent layer α of the glass substrate (1) so that the thickness after curing would be 50 μm. Next, a thiourethane-based optical resin sheet α (1) was laminated on the surface on which the adhesive resin composition was applied. Next, the surface of the glass substrate (1) opposite the surface on which the thiourethane-based optical resin sheet α (1) was laminated was sputtered under the same conditions as when the transparent inorganic layer α was formed, to form a transparent inorganic layer β on the surface of the glass substrate (1). Next, a silane coupling agent layer β was formed on the transparent inorganic layer β of the glass substrate (1) under the same conditions as when the transparent inorganic layer α was formed. Next, the adhesive resin compositions shown in Table 1 were applied to the silane coupling agent layer β of the glass substrate (1) so that the thickness after curing would be 50 μm. Next, a thiourethane-based optical resin sheet β(1) was laminated on the surface on which the adhesive resin composition was applied, and ultraviolet light having a wavelength of 405 nm was irradiated at an irradiation intensity of 600 mW / cm. ２ The two layers of adhesive resin composition were simultaneously cured to obtain optical laminates.

[0072] (Examples 2 and 4) (Double-sided bonding, sequential curing) A glass substrate (1) was sputtered under the same conditions as when the transparent inorganic material layer α of Example 1 was formed, to form a transparent inorganic material layer α on the surface of the glass substrate (1). Next, a silane coupling agent layer α was formed on the transparent inorganic material layer α of the glass substrate (1) under the same conditions as when the silane coupling agent layer α of Example 1 was formed. Next, an adhesive resin composition shown in Table 1 was applied to the silane coupling agent layer α of the glass substrate (1) so that the thickness after curing would be 50 μm. Next, a thiourethane-based optical resin sheet α (1) was laminated on the surface on which the adhesive resin composition was applied, and ultraviolet light having a wavelength of 405 nm was irradiated at an irradiation intensity of 600 mW / cm. ２The adhesive resin composition was cured by irradiating with UV light for 50 seconds to obtain a cured laminate Y. Next, the surface of the glass substrate (1) opposite to the surface on which the thiourethane-based optical resin sheet α (1) of the obtained cured laminate Y was laminated was sputtered under the same conditions as when the transparent inorganic material layer α of Example 1 was formed, thereby forming a transparent inorganic material layer β on the surface of the glass substrate (1). Next, a silane coupling agent layer β was formed on the transparent inorganic material layer β of the glass substrate (1) under the same conditions as when the silane coupling agent layer α of Example 1 was formed. Next, an adhesive resin composition shown in Table 1 was applied to the silane coupling agent layer β of the glass substrate (1) so that the thickness after curing was 50 μm. Next, a thiourethane-based optical resin sheet β (1) was laminated on the surface on which the adhesive resin composition was applied, and ultraviolet light having a wavelength of 405 nm was irradiated at an irradiation intensity of 600 mW / cm. ２ The adhesive resin composition was cured by irradiation at 70° C. for 50 seconds, and then annealed at 70° C. for 120 minutes to obtain an optical laminate.

[0073] (Comparative Examples 1 and 2) (Single-Sided Bonding) A glass substrate (1) was sputtered under the same conditions as when the transparent inorganic material layer α of Example 1 was formed, to form a transparent inorganic material layer on the surface of the glass substrate (1). Next, a silane coupling agent layer was formed on the transparent inorganic material layer of the glass substrate (1) under the same conditions as when the silane coupling agent layer α of Example 1 was formed. Next, an adhesive resin composition shown in Table 1 was applied to the silane coupling agent layer of the glass substrate (1) so that the thickness after curing would be 50 μm. Next, a thiourethane-based optical resin sheet α (1) was laminated on the surface on which the adhesive resin composition was applied, and ultraviolet light having a wavelength of 405 nm was irradiated at an irradiation intensity of 600 mW / cm. ２ The adhesive resin composition was cured by irradiation with light at a rate of 1000 kJ / cm for 50 seconds, and an optical laminate was obtained.

[0074] <Preparation of Samples for Evaluating Adhesive Layer> Each adhesive resin composition shown in Table 1 was applied to a PET sheet so that the thickness after curing would be 0.1 mm. Then, ultraviolet light with a wavelength of 405 nm was irradiated at an intensity of 600 mW / cm. ２The adhesive resin composition was then irradiated with light at 1000 V for 50 seconds to cure the adhesive resin composition. The cured adhesive resin composition was then peeled off from the PET sheet and cut into a piece 10 mm wide and 20 mm long to obtain a sample for evaluating the adhesive layer.

[0075] <Glass Transition Temperature of Adhesive Layer> The glass transition temperature of the adhesive layer evaluation sample obtained by the above method was measured under the following conditions. The results are shown in Table 1. Apparatus: DMA7100 (manufactured by Hitachi High-Tech Science Corporation) Temperature range: 0 to 200°C Heating rate: 5°C / min Measurement interval: 3 seconds Measurement frequency: 1 Hz Measurement mode: Tension

[0076] <Loss modulus of adhesive layer> The loss modulus of the adhesive layer evaluation sample obtained by the above method was measured under the following conditions. The results are shown in Table 1. Apparatus: DMA7100 (manufactured by Hitachi High-Tech Science Corporation) Sample shape: Width 10 mm × Thickness 0.1 mm × Length 20 mm Measurement temperature: 25°C Measurement frequency: 1 Hz Measurement mode: Tension

[0077] <Warpage of Optical Laminate> The optical laminate obtained by the above method was allowed to stand at 50°C for 30 minutes, and then the warpage was measured under the following conditions. Apparatus: UA3P (manufactured by Panasonic Production Engineering Co., Ltd.) Measurement area: Circular area of ​​±30 mm from the center of the optical laminate in the X and Y directions The obtained warpage was evaluated according to the following criteria. The results are shown in Table 1. A: 50 μm or less B: More than 50 μm to 200 μm or less C: More than 200 μm

[0078]

[0079] Warpage was suppressed in the optical laminates of the examples, which shows that warpage can be suppressed in the optical laminate of this embodiment.

[0080] This application claims priority based on Japanese Patent Application No. 2023-118138, filed on July 20, 2023, the disclosure of which is incorporated herein by reference in its entirety.

[0081] REFERENCE SIGNS LIST 1 Optical substrate 2 (Thio)urethane-based optical resin layer α 3 (Thio)urethane-based optical resin layer β 10 Optical laminate 11 Light irradiation unit 12 Light 13 Eye 20 Optical information transmission device

Claims

1. an optical substrate; a (thio)urethane-based optical resin layer α on one surface α side of the optical substrate; a (thio)urethane-based optical resin layer β on a surface β side opposite to the surface α of the optical substrate; An optical laminate comprising:

2. 2. The optical laminate according to claim 1, wherein the (thio)urethane-based optical resin layer α and the (thio)urethane-based optical resin layer β each have a thickness of 2.0 mm or less.

3. 3. The optical laminate according to claim 1, wherein the refractive index of each of the (thio)urethane-based optical resin layer α and the (thio)urethane-based optical resin layer β is 1.47 or more at a temperature of 25°C and a wavelength of 587.6 nm in accordance with JIS K-0062:1992.

4. 3. The optical laminate according to claim 1, wherein the refractive index of the optical substrate is 1.47 or more at a temperature of 25° C. and a wavelength of 587.6 nm according to JIS K-0062:1992.

5. The optical laminate according to claim 1 or 2, wherein the optical substrate comprises one or more substrates selected from the group consisting of glass substrates and optical crystal substrates.

6. an adhesive layer α between the optical substrate and the (thio)urethane-based optical resin layer α; an adhesive layer β between the optical substrate and the (thio)urethane-based optical resin layer β; The optical laminate according to claim 1 or 2, further comprising:

7. The optical laminate according to claim 6 , wherein the thickness of the adhesive layer α and the thickness of the adhesive layer β are each 0.5 μm or more and 1000 μm or less.

8. The optical laminate according to claim 6 , further comprising a transparent inorganic layer at least one between the optical substrate and the adhesive layer α and between the optical substrate and the adhesive layer β.

9. The optical laminate according to claim 6 , further comprising a coupling agent layer at least one between the optical substrate and the adhesive layer α and between the optical substrate and the adhesive layer β.

10. The amount of warpage F of the surface A on the (thio)urethane-based optical resin layer α side of the optical laminate after the optical laminate was left standing at 50° C. for 30 minutes Ａ The optical laminate according to claim 1 or 2, wherein the thickness is 200 μm or less.

11. The optical laminate is left standing for 360 hours in an environment of a temperature of 60°C and a humidity of 90%, and then the surface A of the optical laminate on the (thio)urethane-based optical resin layer α side is measured with a non-contact optical flatness meter to obtain the warpage F of the surface A. Ａ The optical laminate according to claim 1 or 2, wherein the thickness is 350 μm or less.

12. 3. The optical laminate according to claim 1, wherein the refractive index of the optical laminate is 1.47 or more at a temperature of 25° C. and a wavelength of 587.6 nm according to JIS K-0062:1992.

13. The optical laminate according to claim 1 or 2, which can be used in a wearable device.

14. a step (A) of preparing a laminate X including an optical substrate, a (thio)urethane-based optical resin layer α on one surface α of the optical substrate, an uncured or semi-cured adhesive layer α between the optical substrate and the (thio)urethane-based optical resin layer α, a (thio)urethane-based optical resin layer β on a surface β of the optical substrate opposite to the surface α, and an uncured or semi-cured adhesive layer β between the optical substrate and the (thio)urethane-based optical resin layer β; a step (B) of simultaneously curing the uncured or semi-cured adhesive layer α and the uncured or semi-cured adhesive layer β to obtain an optical laminate; A method for producing an optical laminate, comprising:

15. The method for producing an optical laminate according to claim 14 , further comprising, before the step (B), a step (C) of placing the laminate X in a reduced pressure environment.

16. a step (D) of preparing a laminate Y including an optical substrate, a (thio)urethane-based optical resin layer α on one surface α of the optical substrate, and an uncured or semi-cured adhesive layer α between the optical substrate and the (thio)urethane-based optical resin layer α; a step (E) of curing the uncured or semi-cured adhesive layer α to obtain a cured laminate Y; a step (F) of preparing a laminate Z including the cured laminate Y, a (thio)urethane-based optical resin layer β on the surface β side of the cured laminate Y facing the optical substrate, and an uncured or semi-cured adhesive layer β between the cured laminate Y and the (thio)urethane-based optical resin layer β; a step (G) of curing the uncured or semi-cured adhesive layer β to obtain an optical laminate; A method for producing an optical laminate, comprising:

17. The method for producing an optical laminate according to claim 16 , further comprising, before the step (E), a step (H) of placing the laminate Y in a reduced pressure environment.

18. The method for producing an optical laminate according to claim 16 or 17, further comprising a step (I) of placing the laminate Z in a reduced pressure environment before the step (G).

19. Further comprising a step (J) of annealing the optical laminate; The glass transition temperatures of the adhesive layers α and β are defined as T １ When the annealing temperature T ２ But (T １ +5)℃ or higher (T １ The method for producing an optical laminate according to any one of claims 14 to 17, wherein the temperature is +20) ° C. or lower.

20. The annealing temperature T ２ The method for producing an optical laminate according to claim 19, wherein the temperature is 60°C or higher.

21. A light irradiation unit; The optical laminate according to claim 1 or 2, An optical information transmission device comprising: