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

Abstract

An optical laminate (10) comprising an optical substrate (1), a (thio) urethane-based optical resin layer (2) on at least one surface of the optical substrate (1), and an adhesive layer (3) between the optical substrate (1) and the (thio) urethane-based optical resin layer (2), the adhesive layer (3) having a glass transition temperature of 70 DEG C or less.

Description

Technical Field

[0001] This invention relates to optical laminates, methods for manufacturing optical laminates, and optical information transmission devices. Background Technology

[0002] In recent years, the demand for resin materials in the field of optical devices has increased due to reasons such as lightweighting and improved impact resistance. For example, the use of resin materials is required in optical devices worn on the human body, such as wearable devices.

[0003] In Patent Document 1, in order to provide a lightweight optical component capable of high-precision optical information transmission, an optical component comprising an organic polymer with an area of ​​1 mm² is disclosed. 2 The above includes measurements of an area of ​​1 mm² using a non-contact optical flatness meter. 2 When considering the flatness of the region, the aforementioned flatness is for surface A, which is less than 80 μm.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: International Publication No. 2020 / 170801 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] The present invention provides an optical laminate consisting of an optical substrate and a (thio)urethane-based optical resin layer capable of suppressing warping.

[0009] Methods for solving problems

[0010] That is, according to the present invention, an optical laminate, a method for manufacturing an optical laminate, and an optical information transmission device are provided as shown below.

[0011] 1. An optical laminate comprising:

[0012] Optical substrate,

[0013] The (thio)urethane-based optical resin layer on at least one side of the aforementioned optical substrate, and

[0014] The adhesive layer between the aforementioned optical substrate and the aforementioned (thio)carbamate-based optical resin layer.

[0015] The glass transition temperature of the above adhesive layer is below 70°C.

[0016] 2. According to the optical laminate described in 1, the loss modulus of the adhesive layer measured under the conditions of tension, temperature 25°C, and measurement frequency 1Hz is 0.001 GPa or more and 1.5 GPa or less.

[0017] 3. In the optical laminate according to 1 or 2, the thickness of the adhesive layer is 0.5 μm or more and 1000 μm or less.

[0018] 4. The optical laminate according to any one of 1 to 3, wherein the curing shrinkage rate obtained by the following formula (1) is 10% or less, based on the density D0 of the adhesive layer before curing and the density D1 after curing as measured according to JIS K-5600-2-4:2014.

[0019] Curing shrinkage rate (%) = (D1 - D0) / D0 (1)

[0020] 5. The optical laminate according to any one of 1 to 4, wherein the refractive index of the adhesive layer at a temperature of 25°C and a wavelength of 587.6 nm, in accordance with JIS K-0062:1992, is 1.47 or higher.

[0021] 6. The optical laminate according to any one of 1 to 5, wherein the adhesive layer comprises one or more of the group consisting of (meth)acrylic resins and epoxy resins.

[0022] 7. The optical laminate according to any one of 1 to 6, wherein the adhesive layer is composed of a cured adhesive resin composition, wherein the adhesive resin composition is a photocurable resin composition or a thermosetting resin composition.

[0023] 8. In any one of claims 1 to 7, the thickness of the (thio)carbamate-based optical resin layer is 2.0 mm or less.

[0024] 9. The optical laminate according to any one of 1 to 8, wherein the refractive index of the (thio)carbamate-based optical resin layer at a temperature of 25°C and a wavelength of 587.6 nm, according to JIS K-0062:1992, is 1.47 or higher.

[0025] 10. The optical laminate according to any one of 1 to 9, wherein the optical substrate comprises one or more selected from the group consisting of a glass substrate and an optical crystal substrate.

[0026] 11. The optical laminate according to any one of 1 to 10, wherein 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 1.47 or higher.

[0027] 12. The optical laminate according to any one of 1 to 11, further comprising a transparent inorganic layer between the optical substrate and the adhesive layer.

[0028] 13. The optical laminate according to any one of 1 to 12, further comprising a coupling agent layer between the optical substrate and the adhesive layer.

[0029] 14. The optical laminate according to any one of 1 to 13, wherein the warpage F of the surface A on the side of the (thio)carbamate-based optical resin layer in the optical laminate is... A It is below 350μm.

[0030] 15. The optical laminate according to any one of 1 to 14, when the optical laminate is left to stand for 360 hours at a temperature of 60°C and a humidity of 90%, the (thio)urethane-based optical resin layer will not peel off from the optical substrate.

[0031] 16. The optical laminate according to any one of 1 to 15, wherein 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 1.47 or higher.

[0032] 17. The optical laminate according to any one of 1 to 16, which can be used in wearable devices.

[0033] 18. A method for manufacturing an optical laminate, comprising:

[0034] A step (A) of preparing a laminate, wherein the laminate comprises an optical substrate, a (thio)urethane-based optical resin layer on at least one side of the optical substrate, and an uncured or semi-cured adhesive layer between the optical substrate and the (thio)urethane-based optical resin layer; and

[0035] Step (B) involves curing the uncured or semi-cured adhesive layer to obtain an optical laminate.

[0036] 19. The method for manufacturing an optical laminate according to 18 further includes a step (C) of placing the laminate in a depressurized environment before the above-mentioned step (B).

[0037] 20. An optical information transmission device, comprising: a light irradiation unit and an optical laminate as described in any one of 1 to 17.

[0038] Effects of the Invention

[0039] According to the present invention, an optical laminate consisting of an optical substrate and a (thio)urethane-based optical resin layer can be provided, which is capable of suppressing warping. Attached Figure Description

[0040] Figure 1 This is a cross-sectional view schematically showing an example of an optical laminate of this embodiment.

[0041] Figure 2 This is a cross-sectional view schematically showing an example of the optical information transmission device of this embodiment. Detailed Implementation

[0042] The present invention will now be described based on embodiments.

[0043] When numerical ranges are recorded in stages, the upper and lower limits of each numerical range can be combined arbitrarily.

[0044] [Optical laminate]

[0045] The optical laminate of this embodiment will now be described in detail.

[0046] use Figure 1 The optical laminate of this embodiment will be described. The optical laminate 10 of this embodiment includes an optical substrate 1, a (thio)urethane-based optical resin layer 2 on at least one side of the optical substrate 1, and an adhesive layer 3 between the optical substrate 1 and the (thio)urethane-based optical resin layer 2, wherein the glass transition temperature of the adhesive layer 3 is 70°C or less.

[0047] The mechanism by which the optical laminate of this embodiment solves the above-mentioned problems is not yet clear, but it is speculated that the above-mentioned problems are solved by the following mechanism.

[0048] First, as a premise, due to the difference in the coefficients of linear expansion between the optical substrate and the (thio)urethane-based optical resin layer, the optical laminate is prone to strain, which in turn easily leads to warping. It is speculated that in the optical laminate of this embodiment, if strain is applied to the optical laminate, the adhesive layer will alleviate the stress, thereby suppressing the occurrence of warping.

[0049] <Adhesive layer>

[0050] The adhesive layer of the optical laminate of this embodiment will be described below.

[0051] From the viewpoint of further suppressing warping of the optical laminate and suppressing peeling of the optical laminate, the glass transition temperature of the adhesive layer is preferably 65°C or lower, more preferably 60°C or lower, even more preferably 55°C or lower, even more preferably 50°C or lower, even more preferably 45°C or lower. Furthermore, from the viewpoint of further suppressing warping of the optical laminate and suppressing peeling of the optical laminate in high temperature and / or high humidity environments, it is 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, even more preferably 20°C or higher.

[0052] From the viewpoints of further suppressing warping of the optical laminate and suppressing peeling of the optical laminate, the glass transition temperature of the adhesive layer is preferably -20°C or higher and 70°C or lower, more preferably -10°C or higher and 65°C or lower, even more preferably 0°C or higher and 60°C or lower, even more preferably 10°C or higher and 55°C or lower, even more preferably 15°C or higher and 50°C or lower, and even more preferably 20°C or higher and 45°C or lower.

[0053] The glass transition temperature of the adhesive layer can be determined by dynamic viscoelasticity measurement (DMA). Specifically, it can be determined under the following <Measurement Conditions>.

[0054] <Measurement Conditions>

[0055] Apparatus: Dynamic viscoelasticity measuring device

[0056] Sample shape: 10mm width × 0.1mm thickness × 20mm length

[0057] Heating rate: 5℃ / min

[0058] Measurement mode: Tension

[0059] The glass transition temperature of the adhesive layer can be adjusted by changing its composition. For example, the ratio of high molecular weight components to low molecular weight components (e.g., additives, curing agents, etc.) in the adhesive layer can be adjusted, as can the crosslinking density of the adhesive layer.

[0060] For the loss modulus of the adhesive layer measured under the conditions of tension, temperature 25°C, and measurement frequency 1Hz, from the viewpoint of further suppressing the warping of the optical laminate and suppressing the peeling of the optical laminate, the loss modulus is preferably 0.001 GPa or more, more preferably 0.01 GPa or more, and even more preferably 0.03 GPa or more. Furthermore, from the viewpoint of further suppressing the warping of the optical laminate and suppressing the peeling of the optical laminate, the loss modulus 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.

[0061] From the viewpoints of further suppressing warping of the optical laminate and suppressing peeling of the optical laminate, the loss modulus of the adhesive layer measured under the conditions of tension, temperature 25°C, and measurement frequency 1Hz is preferably 0.001 GPa or more and 1.5 GPa or less, more preferably 0.01 GPa or more and 1.3 GPa or less, even more preferably 0.03 GPa or more and 1.1 GPa or less, even more preferably 0.03 GPa or more and 0.9 GPa or less, even more preferably 0.03 GPa or more and 0.7 GPa or less, even more preferably 0.03 GPa or more and 0.5 GPa or less, and even more preferably 0.03 GPa or more and 0.3 GPa or less.

[0062] The loss modulus of the adhesive layer can be determined by dynamic viscoelasticity (DMA). Specifically, it can be determined under the following <Test Conditions>.

[0063] <Measurement Conditions>

[0064] Apparatus: Dynamic viscoelasticity measuring device

[0065] Sample shape: 10mm width × 0.1mm thickness × 20mm length

[0066] Temperature: 25℃

[0067] Measurement mode: Tension

[0068] The loss modulus of the adhesive layer can be adjusted by changing its composition. For example, the ratio of high molecular weight to low molecular weight components in the adhesive layer can be adjusted, as can the crosslinking density of the adhesive layer.

[0069] From the viewpoint of further suppressing warping of the optical laminate and suppressing peeling of the optical laminate, the thickness of the adhesive layer is 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, even more preferably 15 μm or more. Furthermore, from the viewpoint of reducing the overall thickness of the optical laminate, it is 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, even more preferably 60 μm or less.

[0070] From the viewpoints of reducing the overall thickness of the optical laminate and further suppressing the warping of the optical laminate, and from the viewpoints of suppressing the peeling of the optical laminate, the thickness of the adhesive layer is 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.

[0071] From the viewpoint of further suppressing the warping of the optical laminate and suppressing the peeling of the optical laminate, the curing shrinkage rate obtained by using the following formula (1) based on the density D0 of the adhesive layer before curing and the density D1 after curing as measured according to JIS K-5600-2-4:2014 is preferably 10% or less, more preferably 9% or less, and even more preferably 8% or less, and, for example, can be 0.01% or more, 0.1% or more, or 1% or more.

[0072] Curing shrinkage rate (%) = (D1 - D0) / D0 (1)

[0073] The curing shrinkage rate of the adhesive layer can be adjusted by changing its composition. For example, the ratio of high molecular weight to low molecular weight components in the adhesive layer can be adjusted, as can the crosslinking density of the adhesive layer.

[0074] From the viewpoint of improving the optical properties of the optical laminate, according to JIS K-0062:1992, the refractive index of the adhesive layer at a temperature of 25°C and a wavelength of 587.6 nm is preferably 1.47 or higher, more preferably 1.49 or higher, even more preferably 1.51 or higher, even more preferably 1.53 or higher, and, for example, can be 1.90 or lower, 1.80 or lower, or 1.70 or lower.

[0075] From the viewpoints of further suppressing warping of the optical laminate and suppressing peeling of the optical laminate, the coefficient of linear expansion of the adhesive layer measured under the following <measurement conditions> is preferably 200 × 10⁻⁶. -6 Below / ℃, more preferably 150×10 -6 Below / ℃, and from the viewpoints of further suppressing warping of the optical laminate and suppressing peeling of the optical laminate, the smaller the difference between the coefficient of linear expansion and the coefficient of linear expansion of the optical substrate, the better; therefore, 2×10 is preferred. -6 / ℃ or higher, more preferably 4×10 -6 / ℃ or higher, more preferably 6×10 -6 / ℃ or higher, more preferably 8×10 -6 / ℃ or above.

[0076] <Measurement Conditions>

[0077] Measurement mode: TMA compression mode

[0078] Test load: 50mN

[0079] Heating rate: 5℃ / min

[0080] Test temperature range: 0~200℃

[0081] Measurement atmosphere: Nitrogen (100 ml / min)

[0082] The adhesive layer preferably comprises one or more of the group consisting of (meth)acrylic resins and epoxy resins, and more preferably comprises (meth)acrylic resins.

[0083] The aforementioned adhesive layer may further comprise known adhesives. Examples of known adhesives include, for instance, laminated adhesives composed of organotitanium resins, polyethyleneimine resins, polyurethane resins, polyester resins, oxazoline-containing resins, modified organosilicon resins and alkyl titanates, polyester polybutadiene, etc.; or one-component and two-component polyols and polyisocyanates, aqueous polyurethanes, ionomers, etc. Alternatively, aqueous adhesives based on acrylic resins, vinyl acetate resins, polyurethane resins, polyester resins, etc., may be used. Furthermore, depending on the application of the gas-barrier laminate, other additives such as curing agents and silane coupling agents may be added to the adhesive.

[0084] The adhesive layer is preferably composed of a cured adhesive resin composition, wherein the adhesive resin composition is a photocurable resin composition or a thermosetting resin composition, and more preferably composed of a cured adhesive resin composition, wherein the adhesive resin composition is a photocurable resin composition.

[0085] The viscosity of the above-mentioned adhesive resin composition, measured using a cone-plate viscometer (Brookfield, model DV2T) and a CPA-40G (angle: 0.8°, radius: 24 mm, sample volume: 0.5 mL, shear rate: 7.5 N / s) as the cone rotor, at a temperature of 25°C, is preferably 50 mPa·s or more, more preferably 100 mPa·s or more, even more preferably 200 mPa·s or more, even more preferably 300 mPa·s or more, even more preferably 400 mPa·s or more, and preferably 5000 mPa·s or less, more preferably 2000 mPa·s or less, even more preferably 1000 mPa·s or less, and even more preferably 800 mPa·s or less.

[0086] <(Thio)carbamate-based optical resin layer>

[0087] The (thio)carbamate-based optical resin layer of this embodiment will be described below.

[0088] The aforementioned (thio)carbamate-based optical resin layer comprises a (thio)carbamate-based resin. The (thio)carbamate-based resin can be obtained from iso(thio)cyanate compounds and difunctional or higher active hydrogen compounds. Examples of difunctional or higher active hydrogen compounds include polyol compounds and polythiols.

[0089] Examples of iso(thio)cyanate compounds include hexamethylene diisocyanate, pentamethylene diisocyanate, phenyl diisocyanate, isophorone diisocyanate, bis(isocyanate methyl)cyclohexane, bis(isocyanate cyclohexyl)methane, 2,5-bis(isocyanate methyl)bicyclo-[2.2.1]-heptane, 2,6-bis(isocyanate methyl)bicyclo-[2.2.1]-heptane, toluene diisocyanate, phenyl diisocyanate, and 4,4'-diphenylmethane diisocyanate.

[0090] Examples of polythiols include pentaerythritol tetra(2-mercaptoacetate), pentaerythritol tetra(3-mercaptopropionate), bis(2-mercaptoethyl) sulfide, 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane, 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, and 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane. Thia-undecane, 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithia-undecane, 2,5-dimercaptomethyl-1,4-dithiaane, 1,1,3,3-tetra(mercaptomethylthio)propane, 4,6-bis(mercaptomethylthio)-1,3-dithiaane, 2-(2,2-bis(mercaptomethylthio)ethyl)-1,3-dithiobutane, ethylene glycol bis(3-mercaptopropionate), etc.

[0091] 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, and 2-methyl-2,4-pentanediol. Alcohols such as diols, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 2,5-hexanediol, glycerol, diglycerol, polyglycerol, trimethylolpropane, pentaerythritol, di(trimethylolpropane) and other straight-chain or branched aliphatic alcohols, 1,2-cyclopentanediol, 1,3-cyclopentanediol, 3-methyl-1,2-cyclopentanediol, 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 4,4'-bicyclohexanol, 1,4-cyclohexanediol and other alicyclic alcohols.

[0092] The thickness of the above-mentioned (thio)carbamate-based optical resin layer 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.

[0093] From the viewpoint of improving the optical properties of the optical laminate, according to JIS K-0062:1992, the refractive index of the above-mentioned (thio)carbamate-based optical resin layer at a temperature of 25°C and a wavelength of 587.6 nm is preferably 1.47 or more, more preferably 1.49 or more, even more preferably 1.51 or more, even more preferably 1.53 or more, and, for example, can be 1.90 or less, 1.80 or less, or 1.70 or less.

[0094] From the viewpoints of further suppressing warping and peeling of the optical laminate, the coefficient of linear expansion of the (thio)urethane-based optical resin layer, measured under the following <measurement conditions>, is preferably 100 × 10⁻⁶. -6 Below / ℃, more preferably 80×10 -6 Below / ℃, and from the viewpoints of further suppressing warping of the optical laminate and suppressing peeling of the optical laminate, the smaller the difference between the coefficient of linear expansion and the coefficient of linear expansion of the optical substrate, the better; therefore, 2×10 is preferred. -6 / ℃ or higher, more preferably 4×10 -6 / ℃ or higher, more preferably 6×10 -6 / ℃ or higher, more preferably 8×10 -6 / ℃ or above.

[0095] <Measurement Conditions>

[0096] Measurement mode: TMA compression mode

[0097] Test load: 50mN

[0098] Heating rate: 5℃ / min

[0099] Test temperature range: 23~200℃

[0100] Measurement atmosphere: Nitrogen (100 ml / min)

[0101] <Optical substrate>

[0102] The optical substrate of the optical laminate of this embodiment will be described below.

[0103] The aforementioned optical substrate preferably comprises one or more of the group consisting of glass substrates and optical crystal substrates. Examples of optical crystal substrates include SiC substrates, LiNb2O3 substrates (LN substrates), Al2O3 substrates, sapphire substrates, crystal substrates, and quartz substrates.

[0104] From the viewpoint of improving the optical properties of the optical laminate, according to JIS K-0062:1992, the refractive index of the optical substrate at a temperature of 25°C and a wavelength of 587.6 nm is preferably 1.47 or higher, more preferably 1.49 or higher, even more preferably 1.51 or higher, even more preferably 1.53 or higher, and, for example, can be 1.90 or lower, 1.80 or lower, or 1.70 or lower.

[0105] Regarding the coefficient of linear expansion of the optical substrate measured under the following <measurement conditions>, from the viewpoints of further suppressing warping of the optical laminate and suppressing peeling of the optical laminate, the smaller the difference between the coefficient of linear expansion of the substrate and the coefficient of linear expansion of the adhesive layer and the (thio)urethane-based optical resin layer, the better; therefore, 0.1 × 10⁻⁶ is preferred. -6 / ℃ or higher, more preferably 0.5×10 -6 / ℃ or higher, more preferably 2×10 -6 / ℃ or higher, further preferably 4×10 -6 / ℃ or higher, and, for example, can be 40×10 -6 Below / ℃, it can also be 20×10 -6 / ℃ below.

[0106] <Measurement Conditions>

[0107] Measurement mode: TMA compression mode

[0108] Test load: 50mN

[0109] Heating rate: 5℃ / min

[0110] Test temperature range: 23~200℃

[0111] Measurement atmosphere: Nitrogen (100 ml / min)

[0112] <Other Layers>

[0113] The optical laminate of this embodiment may also include components other than the adhesive layer, the (thio)carbamate optical resin layer, and the optical substrate.

[0114] From the viewpoint of suppressing the peeling of the optical laminate, the optical laminate of this embodiment preferably further includes a transparent inorganic layer between the optical substrate and the adhesive layer.

[0115] There are no particular limitations on the method used to form the transparent inorganic layer; for example, it can be formed by sputtering the surface of an optical substrate. Specifically, the optical substrate is first placed in a vacuum container, and a gas such as argon is introduced. Then, a negative voltage is applied to the surface of the optical substrate to generate a glow discharge, causing the gas atoms to ionize. As a result, the ionized gas atoms collide with the surface of the optical substrate, and particles (atoms / molecules) on the surface of the optical substrate are ejected, adhering to and accumulating on the surface of the optical substrate to form a transparent inorganic layer.

[0116] The thickness of the transparent inorganic layer is not particularly limited, but from the viewpoint of further suppressing the warping of the optical laminate and suppressing the 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, even more preferably 50 nm or more, and, for example, 100 nm or less.

[0117] From the viewpoint of suppressing the peeling of the optical laminate, the optical laminate of this embodiment preferably includes a coupling agent layer between the optical substrate and the adhesive layer.

[0118] The coupling agent contained in the coupling agent layer is not particularly limited; for example, silane coupling agents can be cited. Examples of silane coupling agents include vinyltrimethoxysilane and vinyltriethoxysilane, epoxysilane coupling agents such as 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-epoxypropoxypropylmethyldimethoxysilane, 3-epoxypropoxypropyltrimethoxysilane, 3-epoxypropoxypropylmethyldiethoxysilane and 3-epoxypropoxypropyltriethoxysilane, and (meth)acryloylsilane coupling agents such as 3-methacryloyloxypropylmethyldimethoxysilane, 3-methacryloyloxypropylmethyldiethoxysilane, 3-methacryloyloxypropyltriethoxysilane and 3-acryloyloxypropyltrimethoxysilane.

[0119] The thickness of the coupling agent layer is not particularly limited, but from the viewpoint of further suppressing the warping of the optical laminate and suppressing the 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, even more preferably 10 nm or more, and for example, it can be 50 nm or less.

[0120] In addition to the above-described configuration, the optical laminate of this embodiment may also include, for example, an antistatic layer to prevent the optical laminate from becoming charged, a hard coating to prevent damage to the optical laminate, a moisture-blocking layer to prevent moisture from penetrating into the optical laminate, and an antireflective film to reduce surface reflection of the optical laminate.

[0121] <Properties and Applications of Optical Laminates>

[0122] The physical properties and applications of the optical laminate of this embodiment will be described below.

[0123] The warpage F of surface A on the side of the (thio)carbamate-based optical resin layer in the optical laminate of this embodiment A Preferably, it is 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, for example, it can be 0.01 μm or more.

[0124] Warpage F A Measurements can be performed using an ultra-high precision three-dimensional measuring machine. Specifically, measurements can be performed under the following conditions.

[0125] Device: UA3P (manufactured by Panasonic Production Engineering Co., Ltd.)

[0126] Measurement area: A circular area extending ±30 mm in both the X and Y directions from the center of the optical laminate.

[0127] When the optical laminate of this embodiment is left to stand for 360 hours at a temperature of 60°C and a humidity of 90%, the (thio)urethane-based optical resin layer preferably does not peel off from the optical substrate.

[0128] From the viewpoint of improving the optical properties of the optical laminate, according to JIS K-0062:1992, the refractive index of the optical laminate at a temperature of 25°C and a wavelength of 587.6 nm is preferably 1.47 or higher, more preferably 1.49 or higher, even more preferably 1.51 or higher, even more preferably 1.53 or higher, and, for example, can be 1.90 or lower, 1.80 or lower, or 1.70 or lower.

[0129] The application of the optical laminate in this embodiment is not particularly limited. It can be used in wearable devices, and more specifically, in wearable displays that display virtual reality (VR), augmented reality (AR), and the like.

[0130] [Manufacturing method of optical laminates]

[0131] The manufacturing method of the optical laminate of this embodiment will be described below.

[0132] The method for manufacturing an optical laminate according to this embodiment includes: a step (A) of preparing a laminate, wherein the laminate comprises an optical substrate, a (thio)carbamate-based optical resin layer on at least one side of the optical substrate, and an uncured or semi-cured adhesive layer between the optical substrate and the (thio)carbamate-based optical resin layer; and a step (B) of curing the uncured or semi-cured adhesive layer to obtain the optical laminate.

[0133] The method for manufacturing the optical laminate of this embodiment may further include a step (C) of placing the laminate under a reduced pressure environment before the above-described step (B). This prevents positional shifts of the components during lamination. Furthermore, it prevents the formation of air bubbles between layers.

[0134] The method for manufacturing the optical laminate in this embodiment may further include a step of sputtering the surface of an optical substrate. By sputtering the surface of the optical substrate, a transparent inorganic layer can be formed on the surface of the optical substrate.

[0135] The method for manufacturing the optical laminate in this embodiment may further include a process of surface treatment plasma ashing of the surface of the optical substrate. By plasma ashing the surface of the optical substrate, the surface of the optical substrate can be activated.

[0136] The method for manufacturing the optical laminate of this embodiment may further include a step of coating a coupling agent on the surface of an optical substrate. By coating a coupling agent on the surface of the optical substrate, a coupling agent layer can be formed on the surface of the optical substrate.

[0137] In the manufacturing method of the optical laminate of this embodiment, from the viewpoints of further suppressing the warping of the optical laminate and suppressing the peeling of the optical laminate, it is preferable to coat the surface of the optical substrate that has been sputtered with a coupling agent.

[0138] [Optical Information Transmission Device]

[0139] The optical information transmission device of this embodiment will be described below.

[0140] use Figure 2 The optical information transmission device of this embodiment will be described. The optical information transmission device 20 of this embodiment includes a light irradiation unit 11 and the optical laminate 10 described above.

[0141] The light 12 generated from the light irradiation unit 11 is reflected by the optical laminate 10, and the reflected light shines into the user's eyes 13. Thus, the light generated from the light irradiation unit 11 is recognized by the user wearing the light information transmission device 10.

[0142] The embodiments of the present invention have been described above, but these are merely examples of the present invention, and various configurations other than those described above may also be used.

[0143] Furthermore, the present invention is not limited to the above-described embodiments, and variations and improvements within the scope of achieving the objectives of the present invention are included in the present invention.

[0144] Example

[0145] The present invention will be further described in detail below through embodiments, but the present invention is not limited to the following embodiments as long as it does not depart from its spirit.

[0146] <Optical laminate>

[0147] Prepare the following materials.

[0148] Glass substrate (1) (Made by Corning Incorporated, 80 mm in diameter, 0.5 mm in thickness, refractive index 1.51, coefficient of linear expansion 31.7 × 10⁻⁶) -7 / ℃)

[0149] Thiocarbamate-based optical resin sheet (1) (Made by Mitsui Chemicals, product name SK-600, diameter 78mm, thickness 0.35mm, refractive index 1.67, coefficient of linear expansion 6.5×10⁻⁶) -5 / ℃)

[0150] Adhesive resin composition (A) (acrylic, UV-curable)

[0151] Adhesive resin composition (B) (acrylic, UV-curable)

[0152] Adhesive resin composition (C) (acrylic, UV-curable)

[0153] Adhesive resin composition (D) (acrylic, UV-curable)

[0154] Adhesive resin composition (E) (epoxy-based, thermosetting)

[0155] Adhesive resin composition (F) (epoxy-based, thermosetting)

[0156] (Examples 1-4)

[0157] A transparent inorganic layer was formed on the surface of a glass substrate (1) by sputtering. Metallic Si was used as the sputtering target. Ar and O2 were used as the carrier gases. The sputtering power was 5.5 kW. It should be noted that the method for forming the transparent inorganic layer is not particularly limited and can be achieved by ion-assisted evaporation.

[0158] Next, a silane coupling agent (manufactured by Shin-Etsu Chemical Industry Co., Ltd., product name KBM-5103) is coated on the transparent inorganic layer of the glass substrate (1) to form a silane coupling agent layer with a thickness of 7 nm.

[0159] Next, the adhesive resin compositions shown in Table 1 are coated onto the silane coupling agent layer of the glass substrate (1) to a cured thickness of 50 μm.

[0160] Next, a thiourethane-based optical resin sheet (1) is laminated onto the surface coated with the adhesive resin composition, and irradiated at an intensity of 600 mW / cm. 2 Irradiate the adhesive resin composition with ultraviolet light at a wavelength of 405 nm for 50 seconds to cure it, thereby obtaining optical laminates.

[0161] (Example 5)

[0162] The thickness of the adhesive layer was set to 20 μm, and otherwise, the optical laminate was obtained in the same manner as in Example 1.

[0163] (Example 6)

[0164] The thickness of the adhesive layer was set to 20 μm, and otherwise, the optical laminate was obtained in the same manner as in Example 3.

[0165] (Comparative Examples 1-2)

[0166] A transparent inorganic layer was formed on the surface of a glass substrate (1) by sputtering under the same conditions as in Example 1 when forming a transparent inorganic layer.

[0167] Next, the silane coupling agent layer is formed under the same conditions as when the silane coupling agent layer of Example 1 is formed on the transparent inorganic layer of the glass substrate (1).

[0168] Next, the adhesive resin compositions shown in Table 1 are coated onto the silane coupling agent layer of the glass substrate (1) to a cured thickness of 50 μm.

[0169] Next, a thiourethane-based optical resin sheet (1) is laminated onto the surface coated with the adhesive resin composition, and irradiated at an intensity of 600 mW / cm. 2 Irradiate with ultraviolet light at a wavelength of 405 nm for 50 seconds, and then heat at 80°C for 30 minutes to cure the adhesive resin composition, thereby obtaining optical laminates.

[0170] <Viscosity of adhesive resin compositions>

[0171] The viscosity of the adhesive resin composition was determined using a cone-plate viscometer (Brookfield, model DV2T) with a CPA-40G (angle: 0.8°, radius: 24 mm, sample volume: 0.5 mL, shear rate: 7.5 N / s) as the cone rotor at 25°C. The results are shown in Table 1.

[0172] <Preparation of Samples for Adhesive Layer Evaluation>

[0173] (Examples 1-6)

[0174] The adhesive resin compositions shown in Table 1 were coated onto PET sheets to a cured thickness of 0.1 mm. Then, they were subjected to an irradiation intensity of 600 mW / cm². 2 The adhesive resin composition was cured by irradiating it with ultraviolet light at a wavelength of 405 nm for 50 seconds. Then, the cured adhesive resin composition was peeled off from the PET sheet and cut into samples with a width of 10 mm and a length of 20 mm to obtain samples for evaluating the adhesive layer.

[0175] (Comparative Examples 1-2)

[0176] The adhesive resin compositions shown in Table 1 were coated onto PET sheets to a cured thickness of 0.1 mm. Then, they were subjected to an irradiation intensity of 600 mW / cm². 2 The adhesive resin composition was cured by irradiating it with ultraviolet light at a wavelength of 405 nm for 50 seconds and then heating it at 80°C for 30 minutes. The cured adhesive resin composition was then peeled off from the PET sheet and cut into samples 10 mm wide and 20 mm long to obtain samples for evaluating the adhesive layer.

[0177] <Glass transition temperature of adhesive layer>

[0178] The glass transition temperature was determined using the adhesive layer evaluation sample obtained by the above method under the following conditions. The results are shown in Table 1.

[0179] Device: DMA 7100 (manufactured by Hitachi High Technology Co., Ltd.)

[0180] Temperature range: 0~200℃

[0181] Heating rate: 5℃ / min

[0182] Measurement interval: 3 seconds

[0183] Measurement frequency: 1Hz

[0184] Measurement mode: Tension

[0185] <Loss Modulus of Adhesive Layer>

[0186] The loss modulus was determined using the adhesive layer evaluation sample obtained by the above method under the following conditions. The results are shown in Table 1.

[0187] Device: DMA 7100 (manufactured by Hitachi High Technology Co., Ltd.)

[0188] Sample shape: 10mm width × 0.1mm thickness × 20mm length

[0189] Measurement temperature: 25℃

[0190] Measurement frequency: 1Hz

[0191] Measurement mode: Tension

[0192] <Refractive index of the adhesive layer>

[0193] Using the adhesive layer evaluation sample obtained by the above method, the refractive index at 25°C and 587.6 nm was measured using an Abbe refractometer according to JIS K-0062:1992. The results are shown in Table 1.

[0194] <Curing shrinkage rate of adhesive layer>

[0195] Using the adhesive layer evaluation sample obtained by the above method, the curing shrinkage rate was calculated using the following formula (1) based on the density D0 before curing and the density D1 after curing of the adhesive layer as determined according to JIS K-5600-2-4:2014. The results are shown in Table 1.

[0196] Curing shrinkage rate (%) = (D1 - D0) / D0 (1)

[0197] <Warp of optical laminate (23℃)>

[0198] After the optical laminate obtained by the above method was left to stand at room temperature (23°C) for 1 hour, the warpage was measured under the following conditions.

[0199] Device: UA3P (manufactured by Panasonic Engineering Co., Ltd.)

[0200] Measurement area: A circular area extending ±30 mm in both the X and Y directions from the center of the optical laminate.

[0201] The warpage was evaluated according to the following criteria. The results are shown in Table 1.

[0202] A: Below 100μm

[0203] B: Greater than 100μm and less than 350μm

[0204] C: Greater than 350μm

[0205] [Table 1]

[0206]

[0207] Warpage is suppressed in the optical laminate of the embodiment. Therefore, it can be seen that the optical laminate according to this embodiment can suppress warpage.

[0208] <Warp of optical laminates (50℃)>

[0209] The optical laminate obtained by the above method was left to stand at 50°C for 30 minutes, and the warpage was measured under the following conditions. The results are shown in Table 2.

[0210] Device: UA3P (manufactured by Panasonic Engineering Co., Ltd.)

[0211] Measurement area: A circular area extending ±30 mm in both the X and Y directions from the center of the optical laminate.

[0212] [Table 2]

[0213]

[0214] Increasing the thickness of the adhesive layer reduces warpage. Therefore, increasing the thickness of the adhesive layer can further suppress warpage.

[0215] This application claims priority based on Japanese Patent Application No. 2023-118126, filed on July 20, 2023, the entire disclosure of which is incorporated herein by reference.

[0216] Explanation of reference numerals in the attached figures

[0217] 1 Optical substrate

[0218] 2-(thio)carbamate-based optical resin layer α

[0219] 3-(thio)carbamate optical resin layer β

[0220] 10 Optical laminates

[0221] 11Light irradiation part

[0222] 12 Light

[0223] 13 Eyes

[0224] 20. Optical information transmission device.

Claims

1. An optical laminate comprising: Optical substrate, At least one side of the optical substrate has a (thio)carbamate-based optical resin layer, and The adhesive layer between the optical substrate and the (thio)carbamate-based optical resin layer. The glass transition temperature of the adhesive layer is below 70°C.

2. According to claim 1, the loss modulus of the adhesive layer measured under the conditions of tension, temperature 25°C, and measurement frequency 1Hz is 0.001 GPa or more and 1.5 GPa or less.

3. The optical laminate according to claim 1 or 2, wherein the thickness of the adhesive layer is 0.5 μm or more and 1000 μm or less.

4. The optical laminate according to any one of claims 1 to 3, wherein the curing shrinkage rate obtained by using the following formula (1) is 10% or less, based on the density D0 of the adhesive layer before curing and the density D1 after curing as measured according to JIS K-5600-2-4:2014. Curing shrinkage rate (%) = (D1-D0) / D0 (1).

5. The optical laminate according to any one of claims 1 to 4, wherein the refractive index of the adhesive layer at a temperature of 25°C and a wavelength of 587.6 nm, according to JIS K-0062:1992, is 1.47 or higher.

6. The optical laminate according to any one of claims 1 to 5, wherein the adhesive layer comprises one or more of the group consisting of (meth)acrylic resins and epoxy resins.

7. The optical laminate according to any one of claims 1 to 6, wherein the adhesive layer is composed of a cured adhesive resin composition, wherein the adhesive resin composition is a photocurable resin composition or a thermosetting resin composition.

8. The optical laminate according to any one of claims 1 to 7, wherein the thickness of the (thio)carbamate-based optical resin layer is 2.0 mm or less.

9. The optical laminate according to any one of claims 1 to 8, wherein the refractive index of the (thio)carbamate-based optical resin layer at a temperature of 25°C and a wavelength of 587.6 nm, according to JIS K-0062:1992, is 1.47 or higher.

10. The optical laminate according to any one of claims 1 to 9, wherein the optical substrate comprises one or more selected from the group consisting of a glass substrate and an optical crystal substrate.

11. The optical laminate according to any one of claims 1 to 10, wherein 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 1.47 or higher.

12. The optical laminate according to any one of claims 1 to 11, further comprising a transparent inorganic layer between the optical substrate and the adhesive layer.

13. The optical laminate according to any one of claims 1 to 12, further comprising a coupling agent layer between the optical substrate and the adhesive layer.

14. The optical laminate according to any one of claims 1 to 13, wherein the warpage F of the surface A on the side of the (thio)carbamate-based optical resin layer in the optical laminate is... A It is below 350μm.

15. The optical laminate according to any one of claims 1 to 14, wherein when the optical laminate is left to stand for 360 hours at a temperature of 60°C and a humidity of 90%, the (thio)urethane-based optical resin layer will not peel off from the optical substrate.

16. The optical laminate according to any one of claims 1 to 15, wherein 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 1.47 or higher.

17. The optical laminate according to any one of claims 1 to 16, which can be used in wearable devices.

18. A method for manufacturing an optical laminate, comprising: A step (A) of preparing a laminate, the laminate comprising an optical substrate, a (thio)urethane-based optical resin layer on at least one side of the optical substrate, and an uncured or semi-cured adhesive layer between the optical substrate and the (thio)urethane-based optical resin layer; and Step (B) involves curing the uncured or semi-cured adhesive layer to obtain an optical laminate.

19. The method for manufacturing an optical laminate according to claim 18, further comprising a step (C) of placing the laminate in a depressurized environment prior to step (B).

20. An optical information transmission device, comprising: a light irradiation unit and an optical laminate according to any one of claims 1 to 17.

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