Optical components, methods for manufacturing the same, and optical devices using the optical components

Abstract

This invention provides an optical component having a light guide plate and a low-refractive-index layer, having sufficient strength to suppress their peeling, and exhibiting excellent light guiding performance. An embodiment of the optical component of this invention comprises: a light guide plate, a low-refractive-index layer disposed on one main surface of the light guide plate, a stress-relieving layer disposed on the side of the low-refractive-index layer opposite to the light guide plate and having a storage modulus of 0.01 MPa to 10 MPa, and a protective layer disposed on the side of the stress-relieving layer opposite to the low-refractive-index layer and having a tensile elastic modulus of 20 MPa or more.

Description

Technical Field

[0001] This invention relates to optical components and methods for manufacturing the same, as well as optical devices using the optical components. Background Technology

[0002] Techniques for guiding light by forming a low-refractive-index layer on a light guide plate, optically isolating the light guided into the light guide plate, and minimizing the influence of external factors (e.g., damage or contamination of the light guide plate) are known. For example, optical sheets in which a low-refractive-index layer is laminated onto a light guide plate via an adhesive layer are known. With such techniques, color shift and / or scattering sometimes occur due to the adhesive layer, resulting in light guiding loss. To address this problem, techniques for directly laminating a low-refractive-index layer onto the light guide plate are being investigated. However, if a low-refractive-index layer is directly laminated onto the light guide plate, the low strength of the low-refractive-index layer leads to a reduction in the strength of the laminate itself.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent No. 6606518

[0006] Patent Document 2: Japanese Patent Application Publication No. 2023-048451 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] The present invention was made to solve the above-mentioned prior art problems, and its main objective is to provide an optical component having a light guide plate and a low refractive index layer, having sufficient strength as a laminate, and having excellent light guiding performance.

[0009] Methods for solving problems

[0010] [1] The optical component of the present invention includes: a light guide plate, a low refractive index layer disposed on a main surface of the light guide plate, a stress relief layer disposed on the side of the low refractive index layer opposite to the light guide plate and having a storage modulus of 0.01 MPa to 10 MPa, and a protective layer disposed on the side of the stress relief layer opposite to the low refractive index layer and having a tensile elastic modulus of 20 MPa or more.

[0011] [2] In [1] above, the refractive index of the low refractive index layer is 1.25 or less.

[0012] [3] In [1] or [2] above, the thickness of the low refractive index layer is less than 5 μm.

[0013] [4] In any of the above [1] to [3], the haze of the low refractive index layer is less than 5%.

[0014] [5] In any of the above [1] to [4], the low refractive index layer is directly stacked on the light guide plate.

[0015] [6] In any of the above [1] to [5], the energy storage modulus of the stress relief layer is 0.08 MPa to 0.20 MPa and the thickness is 5 μm to 20 μm.

[0016] [7] According to another aspect of the present invention, an optical device may be provided. The optical device includes the optical components of any one of [1] to [6] above.

[0017] [8] In the above [7], the optical device is selected from AR glasses device, MR glasses device, VR glasses device, lighting device device, or backlight unit of image display device.

[0018] [9] According to another aspect of the present invention, a method for manufacturing an optical component according to any one of [1] to [6] above can be provided. The manufacturing method includes: a step of forming a low refractive index layer on a first substrate to form a first laminate; a step of sequentially disposing a stress relief layer and a second substrate on the low refractive index layer of the first laminate to form an optical laminate; a step of peeling the first substrate from the optical laminate; and a step of laminating the optical laminate after peeling the first substrate to the light guide plate in such a way that the low refractive index layer is adjacent to the light guide plate.

[0019]

[10] In the above [9], the manufacturing method includes: directly laminating the optical laminate after the first substrate has been peeled off with the light guide plate.

[0020] The effects of the invention

[0021] According to embodiments of the present invention, it is possible to realize an optical component having a light guide plate and a low refractive index layer, having sufficient strength as a laminate, and having excellent light guiding performance. Attached Figure Description

[0022] Figure 1 This is a cross-sectional schematic diagram of an optical component according to one embodiment of the present invention.

[0023] Figure 2A This is a cross-sectional schematic diagram illustrating one step in the manufacturing method of the optical component according to an embodiment of the present invention.

[0024] Figure 2B This is a cross-sectional schematic diagram illustrating another step in the manufacturing method of the optical component according to an embodiment of the present invention.

[0025] Figure 2CThis is a cross-sectional schematic diagram illustrating another step in the manufacturing method of the optical component according to an embodiment of the present invention.

[0026] Figure 2D This is a cross-sectional schematic diagram illustrating another step in the manufacturing method of the optical component according to an embodiment of the present invention.

[0027] Figure 2E This is a cross-sectional schematic diagram illustrating another step in the manufacturing method of the optical component according to an embodiment of the present invention.

[0028] Symbol Explanation

[0029] 10 Light guide plates

[0030] 20 Low Refractive Index Layer

[0031] 30 Stress Relief Layer

[0032] 40 Protective layer (second substrate)

[0033] 50 sealing auxiliary layers

[0034] 60 First substrate

[0035] 100 Optical Components Detailed Implementation

[0036] The embodiments of the present invention will be described below, but the present invention is not limited to these embodiments. It should be noted that, for ease of observation, the accompanying drawings are schematic representations, and the thickness, dimensions, and relative ratios of the components of the optical structure shown in the drawings, as well as the thicknesses between the components, differ from the actual figures.

[0037] A. Overall structure of optical components

[0038] Figure 1This is a cross-sectional schematic diagram of an optical component according to one embodiment of the present invention. The optical component 100 shown in the figure includes a light guide plate 10, a low-refractive-index layer 20 disposed on one main surface of the light guide plate 10 (the upper main surface in the example figure), a stress-relieving layer 30 disposed on the side of the low-refractive-index layer 20 opposite to the light guide plate 10, and a protective layer 40 disposed on the side of the stress-relieving layer 30 opposite to the low-refractive-index layer 20. In the embodiment of the present invention, the storage modulus of the stress-relieving layer is 0.01 MPa to 10 MPa, and the tensile modulus of the protective layer is 20 MPa or more. With this configuration, in a structure where the low-refractive-index layer is laminated to the light guide plate without the use of adhesives and binders, sufficient strength as a laminate can be achieved. This effect is significant by placing the stress-relieving layer on the side of the low-refractive-index layer opposite to the light guide plate. The construction of stacking a low-refractive-index layer onto a light guide plate without the use of adhesives and binders can suppress color shift and / or scattering caused by adhesives, etc., and as a result, light guide loss can be suppressed, achieving excellent light guide performance. Therefore, according to embodiments of the present invention, it is possible to realize an optical component having a light guide plate and a low-refractive-index layer, possessing sufficient strength as a laminate, and exhibiting excellent light guide performance. Furthermore, by setting the storage modulus of the stress-relieving layer and the tensile modulus of the protective layer to the ranges described above, the effects of embodiments of the present invention can be significantly enhanced.

[0039] The low-refractive-index layer 20 is typically directly laminated onto the light guide plate 10. In this specification, "direct lamination" means that the two components (here, the low-refractive-index layer and the light guide plate) are laminated together without an adhesive layer or bonding agent layer. Here, "direct lamination" also includes the case where the low-refractive-index layer 20 is laminated onto the light guide plate 10 via an adhesive layer 50, as shown in the example figure. The adhesive layer typically contains a silane coupling agent, and as described later, the resulting adhesive layer itself has neither adhesive nor bonding function. Furthermore, as described later, the thickness of the adhesive layer is very small, sometimes making it difficult to clearly identify as a layer. Therefore, the method shown in the example figure can also be included in "direct lamination." It should be noted that by providing an adhesive layer, superior strength can be achieved without compromising the light-guiding performance of the optical components.

[0040] The total light transmittance of the optical component is preferably 60% or more and 99% or less, more preferably 70% or more and 98% or less, and even more preferably 80% or more and 97% or less. Furthermore, the haze of the optical component is preferably 0.05% or more and 3% or less, more preferably 0.1% or more and 2.5% or less, and even more preferably 0.2% or more and 2% or less. According to embodiments of the present invention, excellent overall transparency of the optical component can be achieved. As a result, the optical component can be suitably used in AR glasses, MR glasses, and VR glasses (hereinafter sometimes collectively referred to as "AR glasses, etc."). It should be noted that "AR" is short for "Augmented Reality," "MR" is short for "Mixed Reality," and "VR" is short for "Virtual Reality."

[0041] Optical components can be elongated or single-piece. Elongated optical components can typically be rolled up.

[0042] The following is a detailed explanation of the constituent elements of optical components.

[0043] B. Light guide plate

[0044] The light guide plate 10 is typically configured such that light incident on the light guide plate propagates within the light guide plate via total internal reflection and exits at a given position in a given direction. The light guide plate can be made of glass or resin. Examples of resins include thermoplastic resins and reactive resins (e.g., resins that cure for non-ionizing radiation such as ultraviolet, visible, and infrared light). Examples of thermoplastic resins include resins with one or more of the following as main components: cyclic olefin copolymers, COC resins such as cyclic olefin resins, COP resins, acrylic resins such as polymethyl methacrylate (PMMA), styrene resins, polycarbonate (PC) resins, polyethylene terephthalate (PET) resins, acrylonitrile, and transparent polyimide resins. Examples of reactive resins include non-ionizing radiation curable resins such as acrylics, epoxy resins, urethane resins, silicone resins, and thiols.

[0045] The refractive index of the light guide plate is preferably 1.4 to 2.5, more preferably 1.5 to 2.4, and even more preferably 1.6 to 2.3. When the refractive index is in this range, good light incident from the outside, good light emitted to the outside, and good total internal reflection within the light guide plate can be achieved.

[0046] C. Low-refractive-index layer

[0047] The low-refractive-index layer 20 typically has voids within it. The porosity of the low-refractive-index layer is preferably 35% by volume or more, more preferably 38% by volume or more, and particularly preferably 40% by volume or more. With a porosity within this range, a low-refractive-index layer with a particularly low refractive index can be formed. The upper limit of the porosity of the low-refractive-index layer is, for example, 90% by volume or less, preferably 75% by volume or less. With a porosity within this range, a low-refractive-index layer with excellent strength can be formed. The porosity is calculated using the Lorentz-Lorenz formula based on the refractive index value measured by an ellipsometer.

[0048] The refractive index of the low-refractive-index layer is, for example, 1.25 or less, preferably 1.23 or less, more preferably 1.22 or less, even more preferably 1.20 or less, and particularly preferably 1.19 or less. On the other hand, the refractive index of the low-refractive-index layer is preferably 1.05 or more, more preferably 1.08 or more, and even more preferably 1.10 or more. By providing a low-refractive-index layer having such a refractive index on the main surface of the light guide plate, light guide loss can be suppressed without substantially affecting the optical properties of the light guide plate, achieving excellent light guide performance. Furthermore, since the low-refractive-index layer can be made very thin as described later, it can contribute to the thinning and lightweighting of optical components (resulting in AR glasses, etc.). In addition, when the refractive index of the low-refractive-index layer is in the range described above, a given mechanical strength can be ensured, and breakage can be suppressed. Unless otherwise specified, the refractive index refers to the refractive index measured at a wavelength of 550 nm, or the refractive index converted to a 550 nm value based on measurements at other wavelengths and refractive index wavelength dispersion. The refractive index is a value measured by the method described in “(1) Refractive index of the low refractive index layer” of the example described later.

[0049] The total light transmittance of the low-refractive-index layer is preferably 85% to 99%, more preferably 87% to 98%, and even more preferably 89% to 97%. By providing a low-refractive-index layer with such a refractive index on the main surface of the light guide plate, the effects brought about by the aforementioned refractive index can be utilized, and excellent transparency can be ensured. As a result, the optical component can be suitable for use in AR glasses, etc.

[0050] The haze of the low-refractive-index layer is, for example, less than 5%, preferably less than 3%. On the other hand, the haze is, for example, 0.05% or more, preferably 0.1% or more. By providing a low-refractive-index layer with such haze on the main surface of the light guide plate, the effects brought about by the aforementioned refractive index can be utilized, and excellent transparency is ensured. As a result, the optical component can be suitably used in AR glasses, etc. The haze can be measured, for example, by the following method.

[0051] A low-refractive-index layer was formed on 50mm × 50mm glass, and the haze was measured using a haze meter (Murakami Color Technology Research Institute Co., Ltd.: HM-150). The haze value was calculated using the following formula.

[0052] Haze (%) = [Diffusion transmittance (%) / Total transmittance (%)] × 100 (%)

[0053] The thickness of the low-refractive-index layer is preferably 5 μm or less, more preferably 4 μm or less, even more preferably 3 μm or less, particularly preferably 2 μm or less, and especially preferably 1.5 μm or less. On the other hand, the thickness of the low-refractive-index layer is preferably 300 nm or more, more preferably 400 nm or more, and even more preferably 500 nm or more. When the thickness of the low-refractive-index layer is within this range, excellent transparency can be ensured, and light leakage can be effectively suppressed.

[0054] The surface roughness Rz of the light guide plate side of the low-refractive-index layer (the first substrate side described later in the manufacturing process) is preferably 200 nm or less, more preferably 100 nm or less, and even more preferably 50 nm or less. Since this surface roughness is essentially a direct transfer of the surface roughness of the side of the first substrate in contact with the low-refractive-index layer, it can be determined when the low-refractive-index layer forming material is applied to the first substrate. When the surface roughness Rz of the low-refractive-index layer is within such a range, the adhesion between the low-refractive-index layer and the light guide plate can be sufficiently ensured in the manufacturing method of the optical component described later. As a result, the first substrate can be properly peeled off without damaging the low-refractive-index layer. It should be noted that Rz refers to the maximum height based on JIS B 0601.

[0055] The low-refractive-index layer can be constructed in any suitable manner as long as it possesses the aforementioned desired properties. The low-refractive-index layer is preferably formed by coating or printing. Materials constituting the low-refractive-index layer can be, for example, those described in International Patent Publication No. 2004 / 113966, Japanese Patent Application Publication No. 2013-254183, and Japanese Patent Application Publication No. 2012-189802. Silicon compounds are typical examples. Examples of silicon compounds include silica compounds; hydrolyzable silanes, their partially hydrolysates and dehydration condensates; silicon compounds containing silanol groups; and activated silica obtained by contacting silicates with acids or ion-exchange resins. Organic polymers; polymerizable monomers (e.g., (meth)acrylic acid monomers and styrene monomers); and curable resins (e.g., (meth)acrylic acid resins, fluorinated resins, and urethane resins). These materials can be used alone or in combination. Low refractive index layers can be formed by coating or printing solutions or dispersions of such materials.

[0056] The size of the voids (pores) in the low refractive index layer refers to the diameter of the major axis of the void (pore) and the diameter of its minor axis. The size of the void (pore) is, for example, 2 nm to 500 nm. The size of the void (pore) is, for example, 2 nm or more, preferably 5 nm or more, more preferably 10 nm or more, and even more preferably 20 nm or more. On the other hand, the size of the void (pore) is, for example, 500 nm or less, preferably 200 nm or less, and even more preferably 100 nm or less. The size range of the void (pore) is, for example, 2 nm to 500 nm, preferably 5 nm to 500 nm, more preferably 10 nm to 200 nm, and even more preferably 20 nm to 100 nm. The size of the void (pore) can be adjusted to a desired size according to the purpose and application. The size of the void (pore) can be quantified by the BET test method.

[0057] The size of the pores was quantified using the BET test method. Specifically, 0.1 g of sample (the formed pore layer) was placed in the capillary of a high-precision gas adsorption capacity measuring device (MicrotracBEL: BELSORP MINI), and then subjected to reduced pressure drying at room temperature for 24 hours to degas the gas within the pore structure. Then, by adsorbing nitrogen gas onto the sample, an adsorption isotherm was plotted to determine the pore size distribution. This allows for the evaluation of the pore size.

[0058] Examples of low-refractive-index layers with internal voids include low-refractive-index layers and / or low-refractive-index layers with at least a portion having an air layer. Low-refractive-index layers typically comprise aerogels and / or particles (e.g., hollow microparticles and / or porous particles). Preferably, the low-refractive-index layer can be a nanoporous layer (specifically, more than 90% of the micropores have a diameter of 10...). -1 nm~10 3 Low refractive index layer in the nm range).

[0059] As the aforementioned particles, any suitable particles can be used. The particles are typically formed from silica-based compounds. Examples of particle shapes include spherical, plate-like, needle-like, string-like, and grape-like clusters. Examples of string-like particles include particles formed by multiple particles having spherical, plate-like, or needle-like shapes linked together in a beaded manner, short fibrous particles (e.g., the short fibrous particles described in Japanese Patent Application Publication No. 2001-188104), and combinations thereof. String-like particles can be linear or branched. Examples of grape-like clusters include particles formed by the aggregation of multiple spherical, plate-like, and needle-like particles into a grape-like cluster. The shape of the particles can be confirmed, for example, by observation using a transmission electron microscope.

[0060] The following describes an example of the specific structure of the low-refractive-index layer. The low-refractive-index layer of this embodiment is formed from one or more constituent units that form a fine porous structure, and these constituent units are chemically bonded together by a catalytic reaction. Examples of the shapes of the constituent units include particle-like, fibrous, rod-like, and plate-like shapes. The constituent units may have only one shape, or they may combine two or more shapes. The following description primarily focuses on the case where the low-refractive-index layer is a porous layer of the aforementioned fine-pore particles chemically bonded together.

[0061] Such a porous layer can be formed, for example, by chemically bonding microporous particles together during the porous layer formation process. It should be noted that, in embodiments of the present invention, the shape of the "particles" (e.g., the aforementioned microporous particles) is not particularly limited; for example, they can be spherical or other shapes. Furthermore, in embodiments of the present invention, the aforementioned microporous particles can be, for example, sol-gel bead-like particles, nanoparticles (hollow nano-silica / nano-hollow sphere particles), nanofibers, etc. Microporous particles typically comprise inorganic materials. Specific examples of inorganic materials include silicon (Si), magnesium (Mg), aluminum (Al), titanium (Ti), zinc (Zn), and zirconium (Zr). These can be used alone or in combination of two or more. In one embodiment, the aforementioned microporous particles are, for example, microporous particles of a silicon compound, and the aforementioned porous body is, for example, an organosilicon porous body. The aforementioned silicon compound microporous particles, for example, comprise pulverized gel-like silica compounds. Another type of low-refractive-index layer, and / or at least partly comprising an air layer, is a void layer formed from fibrous materials such as nanofibers, where the fibrous materials are entangled to form voids and thus form a layer. The method for manufacturing such a void layer is not particularly limited; for example, it can be the same as the void layer of a porous body where the microporous particles are chemically bonded together. As yet another type, void layers using hollow nanoparticles, nanoclay, hollow nanospheres, or magnesium fluoride can be used. The void layer can be formed from a single constituent material or from multiple constituent materials. The void layer can be constructed using a single of the above methods or by incorporating multiple of the above methods.

[0062] In this embodiment, the porous structure of the porous body can be, for example, an open-pore structure with continuous pore structures. An open-pore structure refers to a state where, for example, the pore structures in the aforementioned organosilicon porous body are three-dimensionally connected, or can be considered as a state where the internal voids of the pore structure are continuous. By giving the porous body an open-pore structure, the porosity can be increased. However, when using closed-pore particles (particles each having a pore structure) such as hollow silica, an open-pore structure cannot be formed. On the other hand, when using silica sol particles (a pulverized gel-like silicon compound forming a sol), since these particles have a three-dimensional dendritic structure, an open-pore structure can be easily formed by the deposition and accumulation of these dendritic particles in a coating film (a coating film containing a sol of pulverized gel-like silicon compounds). The low-refractive-index layer is more preferably a monolithic structure with an open-pore structure comprising a variety of fine pore distributions. A monolithic structure, for example, refers to a hierarchical structure comprising a structure containing nanoscale micropores and an open-pore structure formed by the aggregation of these nanoscale micropores. In the case of forming a monolithic structure, for example, fine pores can be used to impart film strength, and large open pores can be used to impart high porosity, thereby achieving a balance between film strength and high porosity. Such a monolithic structure is preferably formed by controlling the pore distribution of the generated void structure in the gel (gel-like silicon compound) before it is pulverized into silica sol particles. Furthermore, for example, when pulverizing the gel-like silicon compound, the particle size distribution of the pulverized silica sol particles can be controlled to a desired size, thereby forming a monolithic structure.

[0063] The low-refractive-index layer, for example as described above, comprises fragments of a gel-like compound chemically bonded together. The form of the chemical bonding (chemical bond) between the fragments in the low-refractive-index layer is not particularly limited; examples include cross-linking bonds, covalent bonds, and hydrogen bonds.

[0064] The volume average particle size of the pulverized material in the low refractive index layer is, for example, 10 nm or more, preferably 20 nm or more, and more preferably 30 nm or more. On the other hand, the volume average particle size is, for example, 500 nm or less, preferably 400 nm or less, and more preferably 300 nm or less. The range of the volume average particle size is, for example, 10 nm to 500 nm, preferably 20 nm to 400 nm, and more preferably 30 nm to 300 nm. The particle size distribution can be measured, for example, by a particle size distribution evaluation device such as dynamic light scattering or laser diffraction, and by an electron microscope such as scanning electron microscope (SEM) or transmission electron microscope (TEM). It should be noted that the volume average particle size is an indicator of the deviation of the particle size of the pulverized material. Specifically, indicators such as D10, D50, and D90 can be used, and in particular, the D50 indicator can be used as the particle size value.

[0065] There are no particular limitations on the types of gel-like compounds. Examples of gel-like compounds include gel-like silicon compounds.

[0066] Furthermore, in the low-refractive-index layer (void layer), the silicon atoms contained therein preferably form siloxane bonds. As a specific example, in all the silicon atoms contained in the void layer, the proportion of unbonded silicon atoms (i.e., residual silanols) is, for example, less than 50%, preferably 30% or less, and more preferably 15% or less.

[0067] The following is an example of a method for forming such a low-refractive-index layer.

[0068] This method typically includes: a precursor formation step, forming a porous structure on a light guide plate as a precursor for a low-refractive-index layer (porosity layer); and a cross-linking reaction step, where a cross-linking reaction occurs within the precursor after the precursor formation step. The method also includes: a liquid preparation step, preparing a liquid containing microporous particles (hereinafter sometimes referred to as "microporous particle liquid" or simply "liquid"); and a drying step, drying the liquid, whereby, in the precursor formation step, the microporous particles in the dried liquid are chemically bonded to each other to form the precursor. The liquid is not particularly limited, and can be, for example, a suspension containing microporous particles. It should be noted that the following description mainly addresses the case where the microporous particles are a pulverized gel-like compound, and the porosity layer is a porous body (preferably an organosilicon porous body) containing the pulverized gel-like compound. However, a low-refractive-index layer can also be formed in cases where the microporous particles are not pulverized gel-like compounds.

[0069] Using the method described above, a low-refractive-index layer (porosity layer) with, for example, a very low refractive index can be formed. The reasons for this are speculated, for example, as follows. However, this speculation does not limit the method for forming the low-refractive-index layer.

[0070] The aforementioned pulverized material is obtained by pulverizing a gel-like silicon compound, thus dispersing the three-dimensional structure of the gel-like silicon compound before pulverization into a state of three-dimensional basic structure. Furthermore, in the above method, by coating the pulverized gel-like silicon compound onto a resin film, a precursor to a porous structure based on the three-dimensional basic structure can be formed. That is, according to the above method, a new porous structure (three-dimensional basic structure) based on the pulverized material coating, different from the three-dimensional structure of the gel-like silicon compound, can be formed. Therefore, in the final porous layer, for example, a low refractive index that functions to the same extent as an air layer can be achieved. Moreover, in the above method, the three-dimensional basic structure is immobilized because the pulverized material is chemically bonded to each other. Therefore, although the final porous layer is a structure with pores, it still maintains sufficient strength and flexibility.

[0071] The specific composition and formation method of the low-refractive-index layer are detailed in, for example, International Publication No. 2019 / 151073. The contents of that publication are incorporated herein by reference.

[0072] D. Stress mitigation layer

[0073] The stress-relief layer 30 is typically composed of an adhesive. The adhesive constituting the stress-relief layer typically has a hardness to the extent that it does not penetrate into the voids of the low-refractive-index layer under normal conditions. Therefore, the storage modulus of the stress-relief layer at 23°C can, for example, be 0.01 MPa (0.1 × 10⁻⁶). 4 The stress-relieving layer has a storage modulus of 0.02 MPa or more at 23°C, more preferably 0.04 MPa or more, even more preferably 0.06 MPa or more, particularly preferably 0.08 MPa or more, and especially preferably 0.10 MPa or more. When the lower limit of the storage modulus is in this range, the adverse effects of the adhesive constituting the stress-relieving layer on the low-refractive-index layer can be suppressed, and the effects (excellent light-guiding performance) brought about by the low-refractive-index layer can be well maintained. On the other hand, the storage modulus of the stress-relieving layer at 23°C is preferably 5 MPa or less, more preferably 3 MPa or less, even more preferably 1 MPa or less, particularly preferably 0.70 MPa or less, especially preferably 0.50 MPa or less, and most preferably 0.20 MPa or less. When the upper limit of the storage modulus is in this range, the stress-relieving layer has excellent durability and a buffering function against external forces (buffering function), and can have the flexibility to suppress peeling and / or breakage of the low-refractive-index layer. The storage modulus is determined as follows: according to the method described in JIS K 7244-1 "Plastics - Test method for dynamic mechanical properties", the value at 23°C is read when the temperature is increased at a rate of 5°C / min within the range of -50°C to 150°C at a frequency of 1 Hz.

[0074] The glass transition temperature (Tg) of the stress-relieving layer is preferably below 0°C, more preferably -100°C to -5°C, and even more preferably -90°C to -10°C. When the Tg of the stress-relieving layer is in such a range, it has the same effect as setting the energy storage modulus to the above range, and a stress-relieving layer that can balance excellent buffering function and excellent light guiding performance can be realized.

[0075] As an adhesive constituting the stress-relieving layer, any suitable adhesive can be used as long as it possesses the aforementioned properties. Typical examples of adhesives include acrylic adhesives (acrylic adhesive compositions). Acrylic adhesive compositions typically contain a (meth)acrylate polymer as the main component (base polymer). The (meth)acrylate polymer can be contained in the adhesive composition at a proportion of, for example, 50% by weight or more, preferably 70% by weight or more, more preferably 90% by weight or more in the solids component of the adhesive composition. As a monomer unit, the (meth)acrylate polymer contains an alkyl (meth)acrylate as the main component. It should be noted that (meth)acrylate refers to acrylates and / or methacrylates. Alkyl groups in alkyl (meth)acrylates can be, for example, straight-chain or branched alkyl groups having 1 to 18 carbon atoms. The average number of carbon atoms in the alkyl group is preferably 3 to 9. In addition to alkyl (meth)acrylates, other monomers constituting the (meth)acrylate polymer include carboxyl-containing monomers, hydroxyl-containing monomers, amide-containing monomers, aromatic (meth)acrylates, heterocyclic (meth)acrylates, and other comonomers. The comonomer is preferably a hydroxyl-containing monomer and / or a heterocyclic (meth)acrylate, more preferably N-acryloylmorpholine. The acrylic adhesive composition preferably contains a silane coupling agent and / or a crosslinking agent. Examples of silane coupling agents include epoxy-containing silane coupling agents. Examples of crosslinking agents include isocyanate crosslinking agents and peroxide crosslinking agents. Details of such stress-relieving layers or acrylic adhesive compositions are described, for example, in Japanese Patent No. 4140736, the description of which is incorporated herein by reference.

[0076] The thickness of the stress-relieving layer can be varied according to the energy storage modulus. That is, considering the buffering function against external forces (buffering function), a larger thickness is preferred; considering the light guiding performance, a smaller thickness is preferred; when the energy storage modulus of the stress-relieving layer is small (flexible), the thickness can be relatively reduced. Taking these factors into consideration, the thickness of the stress-relieving layer is, for example, 1μm to 50μm, preferably 2μm to 40μm, more preferably 3μm to 30μm, further preferably 4μm to 20μm, particularly preferably 5μm to 15μm, and especially preferably 6μm to 12μm. When the thickness is within this range, a stress-relieving layer that can balance excellent buffering function and excellent light guiding performance can be achieved. In this case, the energy storage modulus of the stress relief layer at 23°C can be, for example, 0.08 MPa to 0.20 MPa, or for example, 0.09 MPa to 0.18 MPa, or for example, 0.10 MPa to 0.15 MPa, or for example, 0.12 MPa to 0.14 MPa.

[0077] E. Protective layer

[0078] The tensile modulus of the protective layer 40 is, as described above, 20 MPa or more, preferably 30 MPa or more, more preferably 50 MPa or more, even more preferably 100 MPa or more, and particularly preferably 300 MPa or more. On the other hand, the tensile modulus of the protective layer is preferably 10 GPa or less, more preferably 8 GPa or less, and even more preferably 6 GPa or less. When the tensile modulus of the protective layer is in such a range, excellent surface protection properties can be provided when the optical component is used in practical applications, while suppressing damage to the low-refractive-index layer.

[0079] The Tg of the protective layer is preferably 20°C or higher, more preferably 40°C or higher, even more preferably 60°C or higher, and particularly preferably 70°C or higher. On the other hand, the Tg of the protective layer can be, for example, 250°C or lower. When the Tg of the protective layer is in such a range, it has the same effect as setting the tensile modulus of elasticity to the above range, providing excellent surface protection performance when the optical component is put into practical use, while suppressing the damage of the low refractive index layer.

[0080] The protective layer can be composed of any suitable resin film as long as it meets the above-mentioned characteristics. Examples of resin film forming materials include (meth)acrylic resins, cellulose resins such as cellulose diacetate and cellulose triacetate, cycloolefin resins such as norbornene resins, olefin resins such as polypropylene, polyester resins such as polyethylene terephthalate resins, polyamide resins, polycarbonate resins, and copolymers thereof. (Meth)acrylic resins or polyester resins are preferred. It should be noted that "(meth)acrylic resins" refers to acrylic resins and / or methacrylic resins.

[0081] The thickness of the protective layer can be, for example, from 3 μm to 200 μm. When the thickness of the protective layer is within this range, it is possible to achieve thinner optical components and, when the optical components are used in practical applications, to impart excellent surface protection properties, suppressing damage to the low-refractive-index layer. Furthermore, as described later, the resulting optical laminate (intermediate body) can be endowed with strength suitable for manufacturing optical components as the final product. The thickness of the protective layer can vary depending on the purpose, the constituent materials, etc. For example, the thickness of the protective layer can be from 5 μm to 190 μm, or from 10 μm to 150 μm, or from 15 μm to 130 μm, or from 20 μm to 100 μm.

[0082] A hard coating layer and / or an anti-reflective layer can be provided on the side of the protective layer opposite to the stress-relieving layer. By providing a hard coating layer, damage to the low-refractive-index layer can be further suppressed. The hard coating layer preferably has a pencil hardness of H or higher, more preferably 2H or higher, and even more preferably 3H or higher. On the other hand, the pencil hardness of the hard coating layer is preferably 6H or lower, more preferably 5H or lower. The pencil hardness can be measured based on the "Pencil Hardness Test" of JIS K 5400. The thickness of the hard coating layer can be, for example, 0.5 μm to 30 μm, or, for example, 1 μm to 20 μm, or, for example, 2 μm to 15 μm. Detailed information about the hard coating layer is described, for example, in Japanese Patent Application Publication No. 2011-237789 and Japanese Patent Application Publication No. 2016-224443. The descriptions in these publications are incorporated herein by reference.

[0083] The antireflective layer can be any suitable configuration. Typical configurations of the antireflective layer include: (1) a single layer of low refractive index layer with an optical film thickness of 120 nm to 140 nm and a refractive index of about 1.35 to 1.55; (2) a laminate having a medium refractive index layer, a high refractive index layer, and a low refractive index layer sequentially from the light guide plate side; and (3) a multilayer laminate with alternating high refractive index layers and low refractive index layers. The thickness of such an antireflective layer is, for example, about 5 nm to 300 nm. The antireflective layer can be a cured layer of a non-ionizing radiation curable resin composition. The thickness of such an antireflective layer can be, for example, 1.0 μm to 20 μm, or for example, 2.0 μm to 10 μm, or for example, 3.0 μm to 7.0 μm. For any embodiment, since the constituent materials and formation methods of the antireflective layer are known in the art, detailed descriptions are omitted.

[0084] F. Sealing auxiliary layer

[0085] As described above, the sealing auxiliary layer typically comprises a silane coupling agent. Examples of silane coupling agents include acrylic silane coupling agents, amino silane coupling agents, epoxy silane coupling agents, and mercapto silane coupling agents. Silane coupling agents can be used alone or in combination of two or more. In one embodiment, the silane coupling agent comprises an acrylic silane coupling agent, for example, an acrylic silane coupling agent can be combined with an amino silane coupling agent, an epoxy silane coupling agent, a mercapto silane coupling agent, or a combination thereof (other silane coupling agents). Acrylic silane coupling agents and other silane coupling agents can each be used alone or in combination of two or more. By providing a sealing auxiliary layer containing silane coupling agents, superior strength can be achieved without compromising the light-guiding performance of the optical component.

[0086] Acrylic silane coupling agents are typically silane coupling agents having (meth)acrylic acid groups in their backbone. Examples of acrylic silane coupling agents include 3-methacryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-acryloyloxypropyltrimethoxysilane, 3-acryloyloxypropyltriethoxysilane, methacryloyloxymethyltrimethoxysilane, methacryloyloxymethyltriethoxysilane, acryloyloxymethyltrimethoxysilane, acryloyloxymethyltriethoxysilane, and 3-methacryloyloxypropylmethyldimethoxysilane. Furthermore, a large number of acrylic silane coupling agents are commercially available. Specific examples of commercially available products include KBM-502 and KBM-5103 manufactured by Shin-Etsu Chemical Co., Ltd. 3-acryloyloxypropyltrimethoxysilane or 3-methacryloyloxypropylmethyldimethoxysilane are preferred.

[0087] Examples of amino-based silane coupling agents include γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltriethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, γ-phenylaminopropyltrimethoxysilane, and 3-triethoxysilyl-N-(1,3-dimethylbutylene)propylamine. Furthermore, a large number of amino-based silane coupling agents are commercially available. Specific examples of commercially available products include KBM-903, KBE-9103, KBM-575, and KBM-6123 manufactured by Shin-Etsu Chemical Co., Ltd., and A-1102, A-1122, and A-1170 manufactured by Momentive Performance Materials Japan. The preferred formulation is 3-triethoxysilyl-N-(1,3-dimethylbutylene)propylamine.

[0088] Examples of epoxy silane coupling agents include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltriethoxysilane, and γ-glycidoxypropylmethyldimethoxysilane. Furthermore, a large number of epoxy silane coupling agents are commercially available. Specific examples of commercially available products include KBM-402 and KBM-403 manufactured by Shin-Etsu Chemical Co., Ltd. γ-glycidoxypropylmethyldimethoxysilane is preferred.

[0089] Examples of mercaptosilane coupling agents include γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-mercaptopropylmethyldimethoxysilane, and γ-mercaptopropylmethyldiethoxysilane. Furthermore, a large number of mercaptosilane coupling agents are commercially available. A specific example of a commercially available product is X-12-1056ES manufactured by Shin-Etsu Chemical Co., Ltd.

[0090] When acrylic silane coupling agents and other silane coupling agents are used in combination, and the total amount of silane coupling agents is set to 100, the content ratio of acrylic silane coupling agents to other silane coupling agents is preferably 40 / 60 to 60 / 40, more preferably 45 / 55 to 55 / 45, even more preferably 47 / 53 to 53 / 47, and particularly preferably about 50 / 50.

[0091] The thickness of the sealing auxiliary layer is only required to ensure proper adhesion between the auxiliary light guide plate and the low-refractive-index layer; thinner is preferred. This is because it minimizes adverse effects on light guiding performance. Specifically, the thickness of the sealing auxiliary layer is preferably 500 nm or less, more preferably 100 nm or less, further preferably 50 nm or less, particularly preferably 10 nm or less, especially preferably 5 nm or less, and most preferably 4 nm or less. The thickness of the sealing auxiliary layer can be, for example, 0.5 nm or more, and also, for example, 0.7 nm or more. The thickness of the sealing auxiliary layer can be, for example, 0.8 nm to 3.5 nm, and also, for example, 0.9 nm to 3 nm. When the thickness of the sealing auxiliary layer is very small (e.g., 3 nm or less), as mentioned above, it is sometimes difficult to clearly identify it as a layer.

[0092] The sealing auxiliary layer can be formed by applying a solution obtained by dissolving a silane coupling agent (silane compound) in a suitable solvent (e.g., water, isopropanol) onto the surface of the light guide plate, followed by drying after laminating a low-refractive-index layer. The dried (formed) sealing auxiliary layer itself, as described above, has neither adhesive nor bonding functions, but it assists and / or promotes the sealing between the light guide plate and the low-refractive-index layer during the drying of the solution coating.

[0093] G. Manufacturing methods for optical components

[0094] According to an embodiment of the present invention, a method for manufacturing the above-described optical component can be provided. This manufacturing method includes: a step of forming a low-refractive-index layer on a first substrate to fabricate a first laminate; a step of sequentially disposing a stress-relieving layer and a second substrate on the low-refractive-index layer of the first laminate to fabricate an optical laminate; a step of peeling the first substrate from the optical laminate; and a step of laminating the optical laminate after peeling off the first substrate to the light guide plate such that the low-refractive-index layer is adjacent to the light guide plate. Hereinafter, reference will be made to... Figures 2A-2EEach process is explained in detail. It should be noted that the layering in each process can be done by roll to roll, or by batching methods such as roll to sheet or sheet to sheet.

[0095] G-1. Fabrication process of the first layer of the laminate

[0096] First, such as Figure 2A As shown, a low refractive index layer 20 is formed on the first substrate 60 to fabricate a first laminate. The low refractive index layer can be formed by coating or printing a solution or dispersion of the low refractive index layer forming material described in section C above, and then drying the coated or printed film.

[0097] The peel force between the first substrate 60 and the low-refractive-index layer is preferably 0.5 N / 25 mm or less, more preferably 0.4 N / 25 mm or less, even more preferably 0.3 N / 25 mm or less, particularly preferably 0.2 N / 25 mm or less, and especially preferably 0.15 N / 25 mm or less. On the other hand, this peel force can be, for example, 0.01 N / 25 mm or more, and also, for example, 0.02 N / 25 mm or more. When the peel force between the first substrate and the low-refractive-index layer is in such a range, the resulting optical laminate (intermediate body) has the strength suitable for manufacturing optical components as the final product, and the first substrate can be peeled off well.

[0098] As the first substrate, any suitable configuration can be adopted as long as a low refractive index layer can be formed and the aforementioned peel force exists between the substrate and the low refractive index layer. For example, the first substrate can be a single resin film or a laminated film comprising two or more resin layers. In the case where the first substrate is a single resin film, the specific configuration is as described in the description of the protective layer in section E above.

[0099] When the first substrate is a laminate comprising two or more resin layers, the first substrate typically has a first resin layer and a second resin layer sequentially from the low refractive index layer side. The first resin layer is typically a cured layer of a resin solution coating film, and the second resin layer typically has the same configuration as when the first substrate is a single resin film. In one embodiment, the first resin layer comprises a cyclic olefin resin, and the second resin layer comprises a polyester resin. With this configuration, the strength of the resulting optical laminate and the peelability of the first substrate can be improved.

[0100] G-2. Optical laminate fabrication process

[0101] Next, as Figure 2BAs shown, an optical laminate is fabricated by sequentially stacking a stress-relief layer 30 and a second substrate 40 on a low-refractive-index layer 20 of a first laminate. The stress-relief layer 30 is typically formed on any suitable substrate and then transferred to the first laminate (which is essentially a low-refractive-index layer). The second substrate 40 is bonded to the first laminate via the stress-relief layer 30. Alternatively, as... Figure 2C As shown, a second laminate can be fabricated by forming a stress-relieving layer 30 on the second substrate 40. The first laminate and the second laminate are then stacked via the stress-relieving layer 30 to create a laminate as shown. Figure 2B The optical laminate shown.

[0102] In any of the above embodiments, it is preferable to continuously laminate the stress-relieving layer or the second layer onto the first layer, starting from the fabrication of the first layer. In other words, the optical laminate can be fabricated without temporarily rolling the first layer into a roll. With this configuration, damage or contamination of the low-refractive-index layer when the first layer is rolled into a roll, as well as deformation and / or breakage of the low-refractive-index layer due to tight winding, can be prevented. It should be noted that the resulting optical laminate can be rolled into a roll as needed. The rolled optical laminate can be stored and then supplied to subsequent processes, or it can be supplied to subsequent processes without storage.

[0103] G-3. First Substrate Peeling Process

[0104] Next, as Figure 2D As shown, the first substrate 60 is peeled from the optical laminate. The peeling of the first substrate can be performed in any suitable manner. As described above, the first substrate and the low-refractive-index layer are configured with appropriate peeling force, thus significantly suppressing poor peeling.

[0105] G-4. Optical component manufacturing process

[0106] Finally, the optical laminate after the first substrate 60 has been peeled off is laminated with the light guide plate 10 to fabricate an optical component. The optical laminate and the light guide plate can be directly laminated (not shown in the figure), or as follows: Figure 2E The light guide plate is laminated via the sealing auxiliary layer 50. Lamination can be performed under pressure in any case. The pressure during lamination can be, for example, 0.008 MPa to 5 MPa. In the case of the sealing auxiliary layer, as described above, a solution obtained by dissolving a silane coupling agent in a suitable solvent (e.g., isopropanol, water, or a mixture thereof) can be applied to the surface of the light guide plate, and dried after laminating the low-refractive-index layer, thereby forming the sealing auxiliary layer while simultaneously achieving a tight lamination between the light guide plate and the low-refractive-index layer. The drying temperature can be, for example, 35°C to 150°C, and the drying time can be, for example, 0.5 minutes to 24 hours. It should be noted that in the resulting optical component, the second substrate 40 can function as a protective layer.

[0107] H. Optical equipment

[0108] The optical components described in items A through G above can be applied to optical devices. Therefore, optical devices including the aforementioned optical components are also included in the embodiments of the present invention. Typical examples of optical devices include devices for displaying virtual visual information overlaid, such as AR glasses devices, MR glasses devices, and VR glasses devices. Another typical example of an optical device is an illumination device or a backlight unit for an image display device.

[0109] Example

[0110] The present invention will now be specifically described through examples, but the present invention is not limited to these examples. It should be noted that the methods for measuring each characteristic are as described below. Furthermore, unless otherwise explicitly stated, "%" and "parts" in the examples are based on weight.

[0111] (1) Refractive index of the low-refractive-index layer

[0112] After attaching a low-refractive-index layer with a protective layer to the glass light guide plate, a prism coupler (made by Metricon) is used to incident a laser (λ = 407 nm) from the side of the glass light guide plate. The refractive index at 407 nm is calculated based on the measured value of the total internal reflection angle, and then converted to the refractive index at 550 nm based on the wavelength dispersion of the low-refractive-index film monomer calculated separately by an ellipsometer (made by JA Woollam).

[0113] (2) Strength of optical components

[0114] The optical components obtained in the examples and comparative examples were sampled in strips of 50mm × 140mm, and the light guide plate side was further fixed to a stainless steel plate using double-sided tape. An acrylic adhesive layer (20μm thick) was bonded to a PET film (T100: manufactured by Mitsubishi Resin Film Co., Ltd.), and adhesive tape pieces cut to 25mm × 100mm were bonded to the protective layer of the optical component to prepare a test sample. Next, the test sample was clamped in an Autograph tensile testing machine (manufactured by Shimadzu Corporation: AG-Xplus) with a chuck spacing of 100mm, and a tensile test was performed at a tensile speed of 0.3m / min. The average test force (N / 25mm) obtained from the 50mm peel test was taken as the strength of the optical component. Furthermore, after being exposed to an environment of 60°C / 90%RH for 24 hours, the strength was measured again.

[0115] (3) Light guiding performance

[0116] A prism was attached to the light guide plate of the optical component obtained in the embodiments and comparative examples. The image was incident into the light guide plate and guided by the prism. A prism was also attached to the end of the light guide plate opposite to the light incident portion for the purpose of light emission. The emitted image was evaluated by observing it with the naked eye according to the following criteria.

[0117] ○ (Good): No change in image relative to incident light was observed.

[0118] × (Defect): Compared to the image at incident light, image distortion and / or reduced brightness are observed.

[0119] [Manufacturing Example 1] Preparation of Coating Liquid for Forming Low Refractive Index Layers

[0120] (1) Gel formation of silicon compounds

[0121] Mixture A was prepared by dissolving 0.95 g of methyltrimethoxysilane (MTMS), a precursor of silicon compounds, in 2.2 g of dimethyl sulfoxide (DMSO). 0.5 g of a 0.01 mol / L aqueous oxalic acid solution was added to mixture A, and the mixture was stirred at room temperature for 30 minutes, thereby hydrolyzing MTMS to generate mixture B containing tri(hydroxy)methylsilane.

[0122] Add 0.38 g of 28% ammonia and 0.2 g of pure water to 5.5 g of DMSO, and then further add the above mixture B. Stir at room temperature for 15 minutes to gel tris(hydroxy)methylsilane, thereby obtaining mixture C containing gel-like silicon compounds.

[0123] (2) Aging treatment

[0124] The mixture C containing the gel-like silicon compound prepared as described above was directly incubated at 40°C for 20 hours to perform a curing treatment.

[0125] (3) Crushing process

[0126] Next, the gel-like silicon compound, after being cured as described above, was pulverized into particles ranging from several mm to several cm in size using a scraper. Then, 40 g of isopropanol (IPA) was added to mixture C, gently stirred, and allowed to stand at room temperature for 6 hours to decompose the solvent and catalyst in the gel. Solvent replacement was performed by repeating the same decoction process three times to obtain mixture D. Next, the gel-like silicon compound in mixture D was pulverized (high-pressure, media-free pulverization). The pulverization (high-pressure, media-free pulverization) was performed using a homogenizer (SMT Corporation, trade name "UH-50"). After weighing 1.85 g of the gel-like compound and 1.15 g of IPA from mixture D into a 5 cc screw-top bottle, pulverization was carried out at 50 W and 20 kHz for 2 minutes.

[0127] Through this pulverization process, the gel-like silicon compound in the above-mentioned mixture D is pulverized, thereby forming a sol solution E of the pulverized material. Further, relative to 0.75 g of the sol solution E, 0.062 g of a 1.5 wt% MEK (methyl ethyl ketone) solution of photo-induced alkali production agent (Wako Pure Chemical Industries, Ltd.: trade name WPBG266) and 0.036 g of a 5 wt% MEK solution of bis(trimethoxysilyl)hexane are added to obtain a coating solution for forming a low refractive index layer.

[0128] [Manufacturing Example 2] Preparation of the adhesive constituting the stress-relieving layer

[0129] 90.7 parts by weight of butyl acrylate, 6 parts by weight of N-acryloylmorpholine, 3 parts by weight of acrylic acid, 0.3 parts by weight of 2-hydroxybutyl acrylate, 0.1 parts by weight of 2,2'-azobisisobutyronitrile (as polymerization initiator), and 100 g of ethyl acetate were added to a four-necked flask equipped with a stirrer, thermometer, nitrogen inlet tube, and cooler. After nitrogen purging by slowly stirring and introducing nitrogen, the liquid temperature in the flask was maintained at approximately 55°C for 8 hours to prepare an acrylic polymer solution. Relative to 100 parts of the solid content of the obtained acrylic polymer solution, 0.2 parts by weight of isocyanate crosslinking agent (Coronate L, an adduct of trimethylolpropane and toluene diisocyanate manufactured by Nippon Polyurethanes Co., Ltd.), 0.3 parts by weight of benzoyl peroxide (NYPER BMT, manufactured by Nippon Oils & Fats Co., Ltd.), and 0.2 parts by weight of γ-glycidoxypropylmethoxysilane (KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.) were added to prepare an acrylic adhesive solution. Next, the above acrylic adhesive solution was applied to one side of a silicone-treated polyethylene terephthalate (PET) film (manufactured by Mitsubishi Chemical Polyester Film Co., Ltd., thickness: 38 μm) to form an adhesive layer with a dried thickness of 10 μm. The film was then dried at 150°C for 3 minutes to form the adhesive layer. The resulting adhesive had a storage modulus of 1.3 × 10⁻⁶. 5 Pa (0.13 MPa), Tg -60℃. This adhesive layer was used as a stress-relieving layer.

[0130] [Example 1]

[0131] A commercially available cyclic olefin resin (COP) (manufactured by Zeon Corporation, Japan, "ZEONEX" F52R) was dissolved in a mixed solvent of ethylcyclohexane / limonene (mixing ratio: 80 / 20) to prepare a resin solution (solids concentration 5%). This resin solution was coated onto the surface of a commercially available polyethylene terephthalate (PET) film (50 μm thick) and dried to form a 2 μm thick COP layer, resulting in a laminated film having a first resin layer (COP layer) and a second resin layer (PET layer). The obtained laminated film was used as the first substrate. The low refractive index layer forming coating solution obtained in Manufacturing Example 1 was coated onto the COP layer surface of the first substrate and dried to form a 2 μm thick low refractive index layer. The porosity of the low refractive index layer was 56% by volume, and the refractive index was 1.18. Next, the stress-relieving layer (10 μm thick) formed in Manufacturing Example 2 was transferred to the surface of the low refractive index layer. Furthermore, an acrylic film (30 μm thick, tensile modulus 3650 MPa, Tg: 100 °C) was laminated on the surface of the stress-relieving layer as a protective layer (second substrate) to obtain an optical laminate. The lamination was performed using a roll-to-roll method.

[0132] The first substrate was peeled off from the obtained optical laminate. Meanwhile, the low-refractive-index layer side of the optical laminate after the first substrate was peeled off was bonded to the corona-treated surface of a corona-treated glass plate by means of an aqueous solution (0.5%) of an amino-silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., "KBM-903"), which served as a bonding auxiliary layer. Bonding was performed under a pressure of 0.01 MPa. After bonding, the surface was dried at 40°C for 10 hours to obtain an optical component. It should be noted that the thickness of the bonding auxiliary layer in the obtained optical component was 3 nm. The obtained optical component was subjected to the aforementioned evaluation of "strength" and "light guiding performance." The results are shown in Table 1.

[0133] [Example 2]

[0134] Except for changing the silane coupling agent to an epoxy silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., "KBM-403"), the optical component was manufactured in the same manner as in Example 1. The resulting optical component was subjected to the same evaluation as in Example 1. The results are shown in Table 1.

[0135] [Example 3]

[0136] The optical components were fabricated in the same manner as in Example 1, except that a PET film (75 μm thick, tensile modulus 4000 MPa, Tg: 78 °C) was used instead of an acrylic film as the protective layer (second substrate). The resulting optical components were subjected to the same evaluation as in Example 1. The results are shown in Table 1.

[0137] [Example 4]

[0138] The optical component was fabricated in the same manner as in Example 1, except that a water-based bonding process was used instead of a sealing auxiliary layer. The resulting optical component was subjected to the same evaluation as in Example 1. The results are shown in Table 1.

[0139] [Comparative Example 1]

[0140] A low-refractive-index layer was formed on the same protective layer (second substrate) surface as in Example 1. An optical component was fabricated in the same manner as in Example 1, except that a protective layer / low-refractive-index layer laminate was used. That is, the optical component was fabricated in the same manner as in Example 1, except that a stress-relieving layer was not provided between the protective layer and the low-refractive-index layer. The resulting optical component was subjected to the same evaluation as in Example 1. The results are shown in Table 1.

[0141] [Comparative Example 2]

[0142] Except that the PET film of Example 3 was used as the protective layer (second substrate), the optical component was fabricated in the same manner as in Comparative Example 1. The resulting optical component was subjected to the same evaluation as in Example 1. The results are shown in Table 1.

[0143] [Comparative Example 3]

[0144] A low-refractive-index layer was formed on the surface of the same protective layer (second substrate) as in Example 1, in the same manner as in Example 1. Furthermore, an adhesive layer, identical to the stress-relieving layer of Example 1, was transferred to the surface of the low-refractive-index layer. The resulting laminate was then bonded to a glass plate for a light guide plate, identical to that of Example 1, via the adhesive layer, to obtain an optical component. The resulting optical component underwent the same evaluation as in Example 1. The results are shown in Table 1.

[0145]

[0146] As shown in Table 1, according to the embodiments of the present invention, an optical component having a light guide plate and a low-refractive-index layer, possessing sufficient strength as a laminate, and exhibiting excellent light guiding performance can be obtained. More specifically, it is understood that by providing a stress-relieving layer on the side of the low-refractive-index layer opposite to the light guide plate, the peel force between the light guide plate and the low-refractive-index layer is increased (resulting in increased strength as a laminate), and since neither adhesives nor binders are used in the lamination of the light guide plate and the low-refractive-index layer, excellent light guiding performance can be achieved.

[0147] Industrial applicability

[0148] The optical components of the embodiments of the present invention can be suitably used in optical devices such as AR glasses devices, MR glasses devices, VR glasses devices, lighting devices, and backlight units of image display devices.

Claims

1. An optical component having: Light guide plate, A low-refractive-index layer is disposed on one of the main surfaces of the light guide plate. A stress-relieving layer with a storage modulus of 0.01 MPa to 10 MPa is disposed on the side of the low refractive index layer opposite to the light guide plate, and A protective layer with a tensile modulus of 20 MPa or higher is disposed on the opposite side of the stress-relieving layer from the low-refractive-index layer.

2. The optical component according to claim 1, wherein, The refractive index of the low-refractive-index layer is below 1.

25.

3. The optical component according to claim 2, wherein, The thickness of the low-refractive-index layer is less than 5 μm.

4. The optical component according to claim 3, wherein, The haze of the low-refractive-index layer is less than 5%.

5. The optical component according to claim 1, wherein, The low refractive index layer is directly stacked on the light guide plate.

6. The optical component according to claim 1, wherein, The stress relief layer has a storage modulus of 0.08 MPa to 0.20 MPa and a thickness of 5 μm to 20 μm.

7. An optical device comprising the optical component according to any one of claims 1 to 6.

8. The optical device according to claim 7, wherein the device is selected from AR glasses, MR glasses, VR glasses, lighting devices, or the backlight unit of an image display device.

9. A method for manufacturing an optical component according to any one of claims 1 to 6, the method comprising: The process of forming a low refractive index layer on the first substrate to fabricate the first layer stack; The process of fabricating an optical laminate involves sequentially setting a stress-relieving layer and a second substrate in the low-refractive-index layer of the first laminate. The process of peeling the first substrate from the optical laminate; and The process of laminating the optical laminate after the first substrate has been peeled off with the light guide plate in such a way that the low refractive index layer is adjacent to the light guide plate.

10. The method for manufacturing an optical component according to claim 9, wherein, The optical laminate after the first substrate has been peeled off is directly laminated with the light guide plate.

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