Laminate, optical member, and optical device

Abstract

Provided is a laminate having a low refractive index and excellent mechanical strength. This laminate (10) comprises a void layer (11) and an adhesive layer (12), the adhesive layer (12) being directly laminated on one or both surfaces of the void layer (11), the refractive index of the void layer (11) being 1.30 or less as measured in the state of the laminate (10), the nanoindentation hardness being 0.5 MPa or more as measured by pressing an indenter into the adhesive layer (12) by 2000 nm using a nanoindenter, and the refractive index of the void layer (11) being 1.30 or less as measured in the state of the laminate (10). The peel strength between the void layer (11) and the adhesive layer (12) measured using a tensile testing machine at a tensile speed of 0.3 m / min is 3 N / 25 mm or more.

Description

Technical Field

[0001] This disclosure relates to laminates, optical components, and optical devices. Background Technology

[0002] In optical devices, for example, the use of a low refractive index layer as a total internal reflection layer has been proposed. For instance, Patent Document 1 discloses a laminate in which a layer with a refractive index lower than that of the light guide plate is inserted between the light guide plate and the reflector plate. As the low refractive index layer, for example, a void layer with voids is used to make the refractive index as close as possible to that of air.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 10-62626 Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] Optical components containing void layers are typically used in laminated structures (laminates) bonded together by adhesive layers or bonding layers (hereinafter sometimes collectively referred to as "adhesive bonding layers").

[0008] In the case of a laminate formed by directly stacking a void layer and an adhesive layer, if the adhesive layer is soft, there is a tendency for the interlayer peel strength in the laminate to increase. On the other hand, because the adhesive layer is soft, it penetrates into the voids of the void layer, resulting in a decrease in the porosity of the void layer and a tendency for the refractive index of the void layer contained in the laminate to increase. On the other hand, if the adhesive layer is hard, it does not easily penetrate into the voids of the void layer, so the refractive index of the void layer contained in the laminate can be maintained at a low level, but there is a tendency for the interlayer peel strength (mechanical strength) in the laminate to decrease. Thus, in a laminate containing a void layer and an adhesive layer, there is a trade-off between the refractive index of the void layer contained in the laminate and the interlayer peel strength in the laminate. Therefore, it is desirable to achieve a laminate with high mechanical strength even with a low refractive index.

[0009] Therefore, the purpose of this disclosure is to provide laminates, optical components, and optical devices with low refractive index and excellent mechanical strength.

[0010] Technical solutions for solving technical problems

[0011] To achieve the above objectives, the laminate disclosed herein comprises a void layer and an adhesive layer, wherein the adhesive layer is directly laminated on one or both sides of the void layer. The refractive index of the void layer, as measured in the laminated state, is 1.30 or less. The nanoindentation hardness, measured by pressing an indenter 2000 nm relative to the adhesive layer using a nanoindenter, is 0.5 MPa or more. The peel strength between the void layer and the adhesive layer, measured by a tensile testing machine at a tensile speed of 0.3 m / min, is 3 N / 25 mm or more.

[0012] The optical components disclosed herein comprise the laminates of this disclosure.

[0013] The optical device disclosed herein includes the optical components disclosed herein.

[0014] Invention Effects

[0015] According to this disclosure, it is possible to provide laminates, optical components, and optical devices that have low refractive index and excellent mechanical strength. Attached Figure Description

[0016] Figure 1 (a) and Figure 1 (b) is a cross-sectional view of the structure of the laminate disclosed herein.

[0017] Figure 2 (a) and Figure 2 (b) is a cross-sectional view showing another example of the configuration of the laminate of this disclosure.

[0018] Figure 3 (a) and Figure 3 (b) is a cross-sectional view showing another example of the construction of the laminate of the present disclosure.

[0019] Figure 4 It is a graph showing the relationship between peel strength and refractive index. Detailed Implementation

[0020] Next, examples will be given to illustrate this disclosure in more detail. However, this disclosure is not limited in any way by the following description.

[0021] In this disclosure, "adhesive layer" refers to a layer formed by at least one of an adhesive and a bonding agent. Unless otherwise specified, "adhesive layer" in this disclosure can be an "adhesive layer" formed by an adhesive, an "adhesive layer" formed by a bonding agent, or a layer comprising both an adhesive and a bonding agent. Furthermore, in this disclosure, adhesives and bonding agents are sometimes collectively referred to as "adhesive bonding agents." Generally, a distinction is made between adhesives with weaker adhesion or bonding strength (e.g., adhesives capable of re-peeling the adhered objects) and adhesives with stronger adhesion or bonding strength (e.g., adhesives that cannot re-peel the adhered objects or are extremely difficult to apply) and bonding agents. In this disclosure, there is no explicit distinction between adhesives and bonding agents. Additionally, in this invention, there is no explicit distinction between "adhesive strength" and "bonding force."

[0022] In this disclosure, "on top" or "on the surface" can refer to a state of being on top or in direct contact with the surface, or a state of being separated by other layers, etc.

[0023] In this disclosure, "interlayer" refers to any portion contained between one layer and other layers, including both the one layer and the other layers. That is, for example, in the case of "interlayer between one layer and other layers," it can be any portion of the one layer, any portion of the other layers, or any portion of the other layers contained between the one layer and the other layers. Additionally, it can also be the boundary portion between any two of the one layer, the other layers, and the additional layers.

[0024] [1. Layered structure]

[0025] As described above, the laminate of this disclosure includes a void layer and an adhesive layer. The adhesive layer is directly laminated on one or both sides of the void layer. In this disclosure, the "direct lamination" of the adhesive layer on the void layer can be, for example, the adhesive layer being in direct contact with the void layer, or the adhesive layer being laminated on the void layer through the intermediate layer.

[0026] Figure 1 (a) shows an example of the configuration of the laminate of this disclosure. As shown, the laminate 10 has an adhesive layer 12 directly laminated on one side of the void layer 11. Here, the nanoindentation hardness (hereinafter, sometimes referred to as "nanoindentation hardness") measured by pressing an indenter into the adhesive layer 12 at a depth of 2000 nm using a nanoindentation tester is 0.5 MPa or more. In addition, the interlayer peel strength between the void layer 11 and the adhesive layer 12 measured using a tensile testing machine at a tensile speed of 0.3 m / min is 3 N / 25 mm or more. Furthermore, the refractive index of the void layer 11, as measured as the laminate 10, is 1.30 or less.

[0027] in addition, Figure 1 (b) shows another example of the configuration of the laminate of the present disclosure. As shown, the laminate 10a has an adhesive layer 12 directly laminated on both sides of the void layer 11.

[0028] Furthermore, in the laminate of this disclosure, as described above, there is an intermediate layer between the void layer and the adhesive layer, and the intermediate layer may be a layer formed by combining the void layer and the adhesive layer. Figure 2 This represents an example of such a stacked body as disclosed in this publication. Figure 2 As shown in the figure, the laminate 10b of (a) has an adhesive layer 12 directly laminated on one side of the void layer 11. This laminate 10b has an intermediate layer 13 between the void layer 11 and the adhesive layer 12, except that... Figure 1 (a) is the same as the laminate 10. The intermediate layer 13 is a layer formed by combining the void layer 11 and the adhesive layer 12. Figure 2 As shown in the figure, the laminate 10c of (b) has adhesive layers 12 directly laminated on both sides of the void layer 11. This laminate 10c has an intermediate layer 13 between the void layer 11 and each adhesive layer 12, except that... Figure 1 (b) is the same as the laminate 10a. The intermediate layer 13 is the same as... Figure 2 (a) Similarly, it is a layer formed by combining the void layer 11 with the adhesive layer 12.

[0029] Furthermore, the laminate disclosed herein may or may not include other components besides the void layer, the adhesive layer, and the intermediate layer. The other components are not particularly limited; for example, they may be a substrate. The substrate is also not particularly limited; for example, as described later, it may be a film (e.g., a resin film), a glass plate, etc. Figure 3 This represents an example of such a stacked body as disclosed in this publication. Figure 3 As shown in the figure, the laminate 10d of (a) has a substrate 14 directly contacting the surface of the void layer 11 opposite to the adhesive layer 12 and the surface of the adhesive layer 12 opposite to the void layer 11, respectively. Figure 2 (a) is the same as the stack 10b. Figure 3 As shown in the figure, the laminate 10e of (b) has a substrate 14 directly contacting the surfaces of the adhesive layers 12 on the opposite side of the void layer 11. In addition, it is... Figure 3 (b) is the same as the laminate 10c. Figure 3 (a) and Figure 3In (b), substrates 14 are provided on both sides of the laminate. However, this disclosure is not limited to this; for example, substrates 14 may be provided only on either side. Furthermore, Figure 3 (a) and Figure 3 In (b), the substrate 14 is disposed in direct contact with the void layer 11 or the adhesive layer 12. However, this disclosure is not limited to this, and other constituent elements may exist between the substrate 14 and the void layer 11 or the adhesive layer 12. These other constituent elements are not particularly limited, and may, for example, be optical functional layers. The optical functional layers are also not particularly limited, and may, for example, be optical functional layers used in conventional optical films, such as microlens films, prism films, diffusion films, polarizing reflective films, polarizing films, retardation films, high refractive index layers, etc.

[0030] The void layer is, for example, a chemically bonded void layer of pulverized gel-like silicon compound. By using pulverized gel-like silicon compound, the three-dimensional structure of the gel-like silicon compound is disrupted, forming a new three-dimensional structure different from that of the gel-like silicon compound. Thus, the void layer becomes a layer with a new pore structure (new void structure) that cannot be obtained in a layer formed from the gel-like silicon compound, thereby enabling the formation of a nanoscale void layer with high porosity. Furthermore, when the void layer is, for example, a gel-like silicon compound, the pulverized material is chemically bonded to each other while adjusting the number of siloxane bond functional groups in the gel-like silicon compound. Here, "gel-like silicon compound" refers to a polymeric porous body containing siloxane bonds, for example, a porous body containing sesquioxanes as structural units. Furthermore, after forming a new three-dimensional structure as a precursor to the void layer, chemical bonding (e.g., cross-linking) is performed in the bonding process; therefore, when the void layer is a functional porous body, it has a void structure but can maintain sufficient strength and flexibility. Therefore, according to this disclosure, it is possible to easily and conveniently impart a void layer to various objects.

[0031] In the void layer, the morphology of the chemical bonding of the fragments is not particularly limited, and specific examples of the chemical bonds include covalent bonds, ionic bonds, and metallic bonds. For example, the fragments can be cross-linked with each other through covalent bonds (cross-linking bonding). Alternatively, the chemical bonds of the fragments (e.g., the cross-linking bonds) can be in the form of direct bonding between the fragments, or in the form of indirect bonding between the fragments via other substances such as cross-linking aids, connectors, or spacers. It should be noted that the method for chemically bonding the fragments is as described in the method for manufacturing the void layer described later.

[0032] The crosslinking bonds are, for example, siloxane bonds. Examples of siloxane bonds include, for example, bonds of T2, T3, and T4, as shown below. When the gel-like silicon compound has siloxane bonds, it can have any one type of bond, any two types, or all three types. A higher ratio of T2 to T3 in the siloxane bonds results in greater flexibility and the expected properties of the gel, but the film strength becomes weaker. On the other hand, a higher ratio of T4 in the siloxane bonds tends to result in stronger film, but the pore size becomes smaller, and the flexibility becomes brittle. Therefore, for example, it is preferable to vary the ratio of T2, T3, and T4 depending on the application.

[0033] [Chemical Formula 1]

[0034]

[0035] When the void layer has the siloxane bonds, the ratio of T2, T3 and T4, for example when T2 is relatively represented as "1", is T2:T3:T4 = 1:[1~100]:[0~50], 1:[1~80]:[1~40], 1:[5~60]:[1~30].

[0036] In the void layer, the gel-like silicon compound is, for example, a compound formed by the condensation or partial condensation of silane compounds. The condensation can be exemplified by, for example, dehydration condensation. Furthermore, the state of partial condensation refers to a state where, for example, some of the condensing functional groups (e.g., alkoxy groups) contained in the silane compound are condensed, while other functional groups remain uncondensed. In other words, it can also be described as a state where some silane compounds in the silane compound are siloxane-bonded, while other silane compounds are not bonded. The proportion of the unbonded silane compounds is, for example, less than 50%, less than 30%, or less than 15%.

[0037] The silane compound may include, for example, 1- to 3-functional silane compounds and 4-functional silane compounds. The silane compound may include, for example, at least one of the 1- to 3-functional silane compounds, and may also include a 4-functional silane compound. Examples of 1- to 3-functional silane compounds include, for example, 1- to 3-functional alkoxysilanes. Examples of 4-functional silane compounds include, for example, 4-functional alkoxysilanes. Examples of 1-functional silane compounds include, for example, trimethylmethoxysilane (TMMS), trimethylethoxysilane (TMES), trimethylpropoxysilane (TMPS), etc. Examples of 2-functional silane compounds include, for example, dimethyldimethoxysilane (DDMS), dimethyldiethoxysilane (DDES), dimethyldipropoxysilane (DDPS), etc. Examples of the trifunctional silane compounds include: methyltrimethoxysilane (MTMS), methyltriethoxysilane (MTES), methyltripropoxysilane (MTPS), 3-acryloyloxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 4-vinylbutyltrimethoxysilane, 4-vinylbutyltriethoxysilane, 8-vinyloctyltrimethoxysilane, 8-vinyloctyltriethoxysilane, 10-methacryloyloxydecyltrimethoxysilane, 10-acryloyloxydecyltrimethoxysilane, 10-methacryloyloxydecyltriethoxysilane, 10-acryloyloxydecyltriethoxysilane, etc. Examples of the tetrafunctional silane compounds include: tetramethoxysilane (TMOS), tetraethoxysilane (TEOS), tetrapropoxysilane (TPOS), etc.

[0038] The content ratio of the 4-functional silane compound relative to the 1-3 functional silane compound is, for example, 1-25 mol%. The lower limit of the content ratio is, for example, 2 mol% or more, 3 mol% or more, or 3.5 mol% or more, and the upper limit is, for example, 20 mol% or less, 15 mol% or less, or 10 mol% or less, with a range of, for example, 2-20 mol%, 3-15 mol%, 3.5-15 mol%, or 3.5-10 mol%. It should be noted that, from the viewpoint of ease of pulverization in, for example, the gel pulverization process, the content ratio is preferably not too high. Furthermore, from the viewpoint of improving the strength of the low-refractive-index layer, for example, the content ratio is preferably not too low.

[0039] The void layer is, for example, a void layer formed by the chemical bonding of fragments of the gel-like silicon compound under the coexistence of additives. The additives may include, for example, at least one of a crosslinking reaction promoter and its precursor. The crosslinking reaction promoter may be, for example, an acidic or basic substance. The crosslinking reaction promoter may also be referred to as a catalyst that promotes the chemical bonding (crosslinking bond) between the fragments of the gel-like silicon compound. Furthermore, the precursor of the crosslinking reaction promoter may also be referred to as a substance that generates the crosslinking reaction promoter by light or heat (crosslinking promoter generator).

[0040] As the chemical reaction that enables the gel-like silicon compounds to chemically bond together, the dehydration condensation reaction of the residual silanol groups contained in the silica sol molecules is preferably utilized. By promoting the reaction between the hydroxyl groups of the silanol groups using the crosslinking reaction promoter, continuous film formation that solidifies the porous structure in a short time can be achieved. Examples of crosslinking reaction promoters include photoactive catalysts and thermally active catalysts. According to the photoactive catalyst, for example, in the bonding process described later, the gel-like silicon compounds can be chemically bonded together (e.g., crosslinking) without heating. Thus, for example, in the bonding process, it is difficult to cause shrinkage of the bonded fragments, thereby maintaining a higher porosity. For example, a substance that generates a catalyst by light (photocatalyst generator) can be used in addition to or in place of the photoactive catalyst, or a substance that generates a catalyst by heat (thermal catalyst generator) can be used in addition to or in place of the thermally active catalyst. The photocatalyst generator is not particularly limited, and examples include photoalkali-generating agents (substances that generate alkaline catalysts by light irradiation) and photoacid-generating agents (substances that generate acidic catalysts by light irradiation), with photoalkali-generating agents being preferred. Examples of photoalkali-generating agents include 9-anthrylmethyl N, N-diethylcarbamate (trade name WPBG-018), (E)-1-[3-(2-hydroxyphenyl)-2-propenoyl]piperidine (trade name WPBG-027), and 1-(anthraquinone-2-yl)ethylimidazolium carboxylate. The following compounds are listed: imidazolecarboxylate (trade name WPBG-140), 2-nitrophenylmethyl 4-methacryloyloxypiperidine-1-carboxylate (trade name WPBG-165), 1,2-diisopropyl-3-[bis(dimethylamino)methylene]guanidine 2-(3-benzoylphenyl)propionate (trade name WPBG-266), 1,2-dicyclohexyl-4,4,5,5-tetramethylbiguanidine n-butyltriphenylboronic acid ester (trade name WPBG-300), and 1,5,7-triazabicyclo[4.4.0]dec-5-ene of 2-(9-oxoxazan-2-yl)propionate (Tokyo Chemical Industry Co., Ltd.), and compounds containing 4-piperidinemethanol (trade name HDPD-PB100, manufactured by Heraeus). It should be noted that all trade names containing "WPBG" are trade names of Wako Pure Chemical Industries Co., Ltd.Examples of photoacid-generating agents include aromatic sulfonium salts (trade name SP-170: ADEKA), triarylsulfonium salts (trade name CPI 101A: San-Apro), and aromatic iodonium salts (trade name Irgacure 250: Ciba Japan). Furthermore, the crosslinking reaction promoter that chemically bonds the fragments of the gel-like silicon compound to each other is not limited to the photoactive catalyst and the photocatalyst generator; for example, it can be a thermally active catalyst or a thermal catalyst generator such as urea. Examples of crosslinking reaction promoters that chemically bond the fragments of the gel-like silicon compound to each other include alkaline catalysts such as potassium hydroxide, sodium hydroxide, and ammonium hydroxide, and acid catalysts such as hydrochloric acid, acetic acid, and oxalic acid. Alkaline catalysts are preferred. The crosslinking reaction accelerator and its precursor may be used, for example, by adding at least one of the crosslinking reaction accelerator and its precursor to a sol-particle solution (e.g., a suspension) containing the pulverized material (gel-like silicon compound) just before coating, or in the form of a mixture of at least one of the crosslinking reaction accelerator and its precursor in a solvent. The mixture may be, for example, a coating solution directly added to and dissolved in the sol-particle solution, a solution formed by dissolving at least one of the crosslinking reaction accelerator and its precursor in a solvent, or a dispersion formed by dispersing at least one of the crosslinking reaction accelerator and its precursor in a solvent. The solvent is not particularly limited; examples include water and buffer solutions. The amount of the crosslinking reaction accelerator and its precursor added is not particularly limited, for example, relative to the weight of the gel-like silicon compound, such as 0.01–20% by weight, 0.05–10% by weight, or 0.1–5% by weight.

[0041] The lower limit of the total content of the crosslinking reaction promoter and its precursor relative to the total amount of the 1-3 functional silane compounds and the 4 functional silane compounds is, for example, 1 mol% or more, 1.5 mol% or more, 2 mol% or more, or 2.5 mol% or more, and the upper limit is, for example, 5 mol% or less, 4 mol% or less, 3.5 mol% or less, or 3 mol% or less.

[0042] It should be noted that, in the void layer, without containing the 4-functional silane compound as the silane compound, the lower limit of the total content of the crosslinking reaction promoter and its precursor relative to the total mass of the silane compound is, for example, 1.5 mol% or more, 2 mol% or more, or 2.5 mol% or more, and the upper limit is, for example, 5 mol% or less, 4 mol% or less, 3.5 mol% or less, or 3 mol% or less.

[0043] Additionally, the additive may include, for example, a crosslinking aid. This crosslinking aid can also be described as a medium for indirectly bonding the pulverized gel-like silicon compound to each other through chemical bonding. The crosslinking aid enters between the pulverized particles, allowing them to interact or bond with each other. Thus, even particles that are slightly separated can bond together, effectively increasing strength.

[0044] As the crosslinking aid, a multi-crosslinked silane monomer is preferred. Specifically, the multi-crosslinked silane monomer has, for example, 2 or more and 3 or fewer alkoxysilyl groups, and the chain length between the alkoxysilyl groups can be 1 or more and 10 or fewer carbon atoms, or may contain elements other than carbon. Examples of crosslinking aids include bis(trimethoxysilyl)ethane, bis(triethoxysilyl)ethane, bis(trimethoxysilyl)methane, bis(triethoxysilyl)methane, bis(triethoxysilyl)propane, bis(trimethoxysilyl)propane, bis(triethoxysilyl)butane, bis(trimethoxysilyl)butane, bis(triethoxysilyl)pentane, bis(trimethoxysilyl)pentane, bis(triethoxysilyl)hexane, bis(trimethoxysilyl)hexane, bis(trimethoxysilyl)-N-butyl-N-propyl-ethane-1,2-diamine, tris-(3-trimethoxysilylpropyl)isocyanurate, tris-(3-triethoxysilylpropyl)isocyanurate, etc. The amount of the crosslinking aid added is not particularly limited, for example, it is 0.01~20% by weight, 0.05~15% by weight, or 0.1~10% by weight relative to the weight of the gel-like silicon compound.

[0045] The lower limit of the total content of the crosslinking aid relative to the total amount of the 1-3 functional silane compounds and the 4 functional silane compounds is, for example, 1 mol% or more, 2 mol% or more, 2.5 mol% or more, or 3 mol% or more, and the upper limit is, for example, 6 mol% or less, 5.5 mol% or less, 5 mol% or less, 4.5 mol% or less, or 3.5 mol% or less.

[0046] It should be noted that, in the void layer, when the silane compound does not contain the tetrafunctional silane compound, the lower limit of the total content of the crosslinking aid relative to the total mass of the silane compound is, for example, 2 mol% or more or 2.5 mol% or more, and the upper limit is, for example, 6 mol% or less, 5 mol% or less, 4 mol% or less, 3.5 mol% or less or 3 mol% or less.

[0047] The void layer, for example, has a porous structure. The void size in the void layer refers to the diameter of the major axis of the void (hole). The void size is, for example, 5 nm to 200 nm. The void size is, for example, 5 nm or more, 10 nm or more, or 20 nm or more, with upper limits such as below 200 nm, below 150 nm, below 100 nm, below 50 nm, below 40 nm, or below 30 nm, and ranges such as 5 nm to 200 nm and 10 nm to 100 nm. The preferred void size is determined based on the intended use of the void structure, and therefore, for example, it needs to be adjusted to the desired void size according to the purpose. The void size can be evaluated, for example, by the following methods.

[0048] (SEM observation of the cross-section of the void layer)

[0049] In this disclosure, the morphology of the void layer can be observed and analyzed using SEM (scanning electron microscope). Specifically, for example, the void layer is subjected to FIB processing (accelerating voltage: 30 kV) under cooling, and the resulting cross-sectional sample can be imaged at 100,000x magnification using an FIB-SEM (FEI Corporation: trade name Helios NanoLab 600, accelerating voltage: 1 kV).

[0050] (Evaluation of gap size)

[0051] In this disclosure, the porosity can be quantified using the BET test method. Specifically, 0.1 g of the sample (the porosity layer) is introduced into the capillary of a pore distribution / specific surface area measuring device (BELLSORP MINI / MicrotracBEL, a trade name) and then subjected to reduced pressure drying at room temperature for 24 hours to degas the gas within the porosity structure. Then, by adsorbing nitrogen onto the sample, BET and BJH diagrams and adsorption isotherms are plotted to determine the pore distribution. This allows for the evaluation of the porosity.

[0052] The void layer can, for example, have a porous structure (polyporous structure) as described above, and can be a continuous bubble structure formed by the continuous pore structure. The bubble structure refers to a state in which the pore structure is three-dimensionally connected, or in other words, the internal voids of the pore structure are continuous. When a porous material has a bubble structure, the porosity in the bulk can be increased, but when using isolated bubble particles such as hollow silica, a bubble structure cannot be formed. In contrast, since the sol particles (the pulverized material forming the porous gel) of the void layer have a three-dimensional dendritic structure, the dendritic particles settle and accumulate in the coating film (a coating film containing the pulverized porous gel), thereby easily forming a bubble structure. Furthermore, the void layer is more preferably a monolithic structure with multiple fine pores distributed in the bubble structure. The monolithic structure refers, for example, a structure containing nanoscale micropores and a hierarchical structure existing in the form of a bubble structure formed by the aggregation of these nanoscale micropores. In forming the monolithic structure, for example, it is possible to impart membrane strength using fine pores and to impart high porosity using large interconnected pores, thus achieving a balance between membrane strength and high porosity. To form these monolithic structures, for example, it is important to control the pore distribution of the generated void structure in the porous gel during the initial stage of pulverizing the porous gel. Furthermore, for example, by controlling the particle size distribution of the pulverized material to a desired size during pulverization of the porous gel, the monolithic structure can be formed.

[0053] In the void layer, there is no particular limitation on the haze that indicates transparency, with a lower limit of, for example, 0.1% or more, 0.2% or more, or 0.3% or more, and an upper limit of, for example, 10% or less, 5% or less, or 3% or less, and a range of, for example, 0.1 to 10%, 0.2 to 5%, or 0.3 to 3%.

[0054] The haze can be measured, for example, by the following methods.

[0055] (Evaluation of haze)

[0056] The void layer (the void layer) was cut into 50mm × 50mm pieces and placed in a haze meter (Murakami Color Technology Research Institute Co., Ltd.: HM-150) to measure the haze. The haze value was calculated using the following formula.

[0057] Haze (%) = [Diffusion transmittance (%) / Total transmittance (%)] × 100 (%)

[0058] The refractive index is generally defined as the ratio of the speed at which light travels across the wavefront in a vacuum to the speed at which light travels within a medium. It should be noted that, unless otherwise specified, the refractive index mentioned in this disclosure refers to the refractive index measured at a wavelength of 550 nm. Furthermore, the method for measuring the refractive index is not particularly limited; for example, it can be measured using the methods described below.

[0059] When only the void layer is measured, the refractive index of the void layer is, for example, 1.30 or less. The upper limit of the refractive index of the void layer when only the void layer is measured is, for example, 1.30 or less, less than 1.30, 1.26 or less, 1.25 or less, less than 1.25, 1.24 or less, 1.23 or less, or 1.22 or less; the lower limit is, for example, 1.05 or more, 1.10 or more, 1.15 or more, 1.16 or more, 1.17 or more, 1.18 or more, or 1.19 or more; and the range is, for example, 1.05 or more and 1.30 or less, 1.05 or more and less than 1.30, 1.10 or more and 1.25 or less, 1.15 or more and less than 1.25, or 1.19 or more and less than 1.25. The method for measuring the refractive index of the void layer when only the void layer is measured is not particularly limited; for example, it can be measured by the following methods.

[0060] The lower limit of the porosity of the void layer is, for example, 30% or more or 50% or more, and the upper limit is, for example, less than 90%, less than 75%, or less than 60% of volume, and the range is, for example, 30 to 90% of volume, 50 to 75% of volume, or 50 to 60% of volume.

[0061] (Evaluation of the refractive index of the void layer when only the void layer is measured)

[0062] After forming a void layer (the void layer in the laminate of this disclosure) in the acrylic film, it is cut to a size of 50 mm × 50 mm and bonded to the surface of a glass plate (thickness: 3 mm) using an adhesive layer. Black ink is applied to the central portion of the back side of the glass plate (approximately 20 mm in diameter) to prepare a sample that does not reflect light from the back side of the glass plate. The sample is placed in an ellipsometer (JAWoollam Japan: VASE) and the refractive index is measured at a wavelength of 550 nm and an incident angle of 50–80 degrees. The average value is taken as the refractive index.

[0063] After a heat-humidification durability test at 85°C and 85% RH for 500 hours, the porosity of the void layer is, for example, at a lower limit of 10% by volume or more, 20% by volume or more, 30% by volume or more, 40% by volume or more, 50% by volume or more, 60% by volume or more, 70% by volume or more, 80% by volume or more, 85% by volume or more, or more than 85% by volume. The method for determining the refractive index of the void layer when only the void layer is measured is not particularly limited; for example, it can be determined by the following method.

[0064] (Evaluation of the porosity retention rate of the porous layer)

[0065] The fabricated laminate was placed in an oven at 85°C and 85% RH for 500 hours for a heat-humidification durability test. The degree of pore filling in the void areas of the void layer after the heat-humidification durability test can be confirmed using SEM, and the porosity retention rate can be calculated.

[0066] The thickness of the void layer is not particularly limited, but its lower limit is, for example, above 0.05 μm or above 0.1 μm, and its upper limit is, for example, below 1000 μm, below 100 μm, below 10 μm, below 5 μm or below 2 μm, and its range is, for example, 0.05~1000 μm or 0.1~100 μm.

[0067] The shape of the void layer is not particularly limited; for example, it can be a thin film or a block.

[0068] There are no particular limitations on the method for manufacturing the void layer. For example, it can be manufactured using the void layer manufacturing method described later, or the methods described in International Publication No. 2019 / 065999 and International Publication No. 2019 / 065803. The description in this publication is incorporated herein by reference.

[0069] In this disclosure, the adhesive layer is not particularly limited. In this invention, the adhesive or bonding agent forming the adhesive layer is not particularly limited; for example, general adhesives or bonding agents can be used. Examples of such adhesives or bonding agents include polymer-based adhesives such as acrylic, vinyl alcohol, silicone, polyester, polyurethane, and polyether adhesives, as well as rubber-based adhesives. Additionally, adhesives composed of water-soluble crosslinking agents of vinyl alcohol polymers such as glutaraldehyde, melamine, and oxalic acid can also be included. Only one of these adhesives and bonding agents can be used, or multiple adhesives can be used in combination (e.g., mixing, layering, etc.). The thickness of the adhesive layer is not particularly limited, and is, for example, 0.1–100 μm, 5–50 μm, 10–30 μm, or 12–25 μm.

[0070] In the adhesive layer of the laminate disclosed herein, as described above, the nanoindentation hardness is 0.5 MPa or higher. The lower limit of the nanoindentation hardness can be, for example, 0.55 MPa or higher, 0.6 MPa or higher, or 0.65 MPa or higher, and the upper limit can be, for example, 2.0 MPa or lower, 1.5 MPa or lower, 1.3 MPa or lower, or 1.1 MPa or lower. The method for measuring the nanoindentation hardness is not particularly limited, and it can be measured, for example, by the methods described below.

[0071] (Evaluation of nanoindentation hardness)

[0072] The test sample was cut into approximately 1 cm square pieces and fixed to a specified support. The nanoindentation hardness of the adhesive layer in the laminate of this disclosure was measured under the following conditions. Nanoindentation hardness can be determined using the nanoindentation method.

[0073] • Analytical apparatus: Hysitron Inc., Triboindenter

[0074] • Indenter used: Conical (spherical: 20μm in diameter)

[0075] • Measurement method: Single indentation measurement

[0076] • Measurement temperature: room temperature

[0077] • Indentation depth: 2000nm

[0078] The nanoindentation hardness is calculated using the following formula based on the maximum load (Pmax) and the contact projected area (A) obtained by measurement.

[0079] Nanoindentation hardness = Pmax / A

[0080] It should be noted that the nanoindentation hardness can be any nanoindentation hardness on the surface of the adhesive layer and in the cross-section of the adhesive layer.

[0081] In the laminate of this disclosure, the peel strength between the void layer and the adhesive layer, measured using a tensile testing machine at a tensile speed of 0.3 m / min, is 3 N / 25 mm or more, as described above. The lower limit of this peel strength can be, for example, 3.5 N / 25 mm or more, 4.0 N / 25 mm or more, or 5.0 N / 25 mm or more. The higher the peel strength, the higher the interlayer mechanical strength of the laminate of this disclosure; therefore, the upper limit of the peel strength is not particularly limited, and can be, for example, 20 N / 25 mm or less, 15 N / 25 mm or less, or 10 N / 25 mm or less. The peel strength is, for example, the peel strength measured due to the cohesive failure of the void layer. The method for measuring the peel strength is not particularly limited, and can be measured, for example, by the following methods.

[0082] (Evaluation of interlayer peel strength)

[0083] A substrate having a void layer (the void layer in the laminate of this disclosure) and an adhesive layer (the adhesive layer in the laminate of this disclosure) formed on a resin film substrate is prepared. An acrylic adhesive layer (20 μm thick) is bonded to the side of the resin film substrate opposite to the void layer. The bonded sample is cut into 50 mm × 25 mm pieces to make adhesive tape sheets. Next, the adhesive layer (10 μm thick) on the void layer side is bonded to a strip of PET film (T100: manufactured by Mitsubishi Resin Film Co., Ltd.) cut into 25 mm × 100 mm shapes, and the acrylic adhesive layer on the resin film substrate side is laminated to glass to fix it. The sample thus prepared is clamped in a tensile testing machine (manufactured by Shimadzu Corporation, trade name: Autograph AG-Xplus) with a chuck spacing of 100 mm, and a 180° peel test is performed at a tensile speed of 0.3 m / min. Perform N=3 peel tests at 50mm each, and use the average test force as the peel strength between the layers.

[0084] The refractive index of the void layer, measured in the laminated state, is 1.30 or less as described above. The upper limit of the refractive index of the void layer, measured in the laminated state, is, for example, 1.30 or less, less than 1.30, 1.26 or less, 1.25 or less, less than 1.25, 1.24 or less, 1.23 or less, or 1.22 or less; the lower limit is, for example, 1.05 or more, 1.10 or more, 1.15 or more, 1.16 or more, 1.17 or more, 1.18 or more, or 1.19 or more; and the range is, for example, 1.05 or more and 1.30 or less, 1.05 or more and less than 1.30, 1.10 or more and 1.25 or less, 1.15 or more and less than 1.25, or 1.19 or more and less than 1.25. The method for measuring the refractive index of the void layer, measured in the laminated state, is not particularly limited; for example, it can be measured by the following method.

[0085] (Evaluation of the refractive index of the void layer measured in a laminated state) A prism coupler (manufactured by Metricon) is tightly fitted to the substrate side of a laminate (glass / adhesive layer / void layer / acrylic substrate) with an adhesive layer on the void layer. The critical angle of total internal reflection is measured using a laser. The refractive index can be calculated from the measured critical angle value.

[0086] The laminate of this disclosure, for example, when the refractive index is set to X and the peel strength is set to Y, can satisfy the following condition (1). Figure 4 The graph shows the relationship between peel strength and refractive index under condition (1). Additionally, in Figure 4In the diagram, the horizontal axis represents the refractive index, and the vertical axis represents the peel strength (N / 25mm). Condition (1): Y≥80X-93.8

[0087] In addition, the laminate of this disclosure can satisfy the following condition (2) when the refractive index is set to X and the peel strength is set to Y. Figure 4 The graph shows the relationship between peel strength and refractive index under condition (2).

[0088] Condition (2): Y≥100X-117

[0089] When either condition (1) or condition (2) is met, for example, a laminate with low refractive index and high peel strength (i.e., excellent mechanical strength) can be obtained. There are no particular limitations in order to meet conditions (1) and (2), and the type and proportion of the 4-functional silane compound, the additive, etc., can be appropriately adjusted.

[0090] In this disclosure, the intermediate layer is not particularly limited. For example, as described above, it is a layer formed by combining a portion of the void layer and a portion of the adhesive layer. The thickness of the intermediate layer is not particularly limited, for example, it is 1~1500nm, 5~1000nm, 10~800nm ​​or 20~500nm.

[0091] The morphology of the laminates disclosed herein is not particularly limited, but is generally in the form of a thin film.

[0092] The laminate of this disclosure is, for example, a roll. Additionally, the laminate of this disclosure, as described above, may further include a resin film, with the void layer formed on the elongated resin film. In this case, other elongated films may be laminated in the laminate of this disclosure, or it may be a roll formed by laminating other elongated resin films (e.g., backing paper, release film, surface protective film, etc.) in the laminate of this disclosure containing the resin film and the void layer.

[0093] The method for manufacturing the laminate disclosed herein is not particularly limited, and for example, it can be manufactured using the manufacturing method of the present disclosure as shown below. Furthermore, regarding the method for manufacturing the optical laminate of the present disclosure without a resin film, unless otherwise specified, it can be carried out in the same manner as the method for manufacturing the laminate of the present disclosure, except that a resin film is not used.

[0094] [2. Manufacturing method of laminated bodies]

[0095] The method of manufacturing the laminates disclosed herein is not particularly limited, and can be carried out by, for example, the manufacturing method described below. However, the following description is illustrative and does not limit the scope of this disclosure in any way.

[0096] As described above, the method for manufacturing the laminate of this disclosure includes a void layer forming step for forming the void layer and an adhesive layer forming step for forming the adhesive layer on the void layer. The method for manufacturing the laminate of this disclosure may further include an intermediate layer forming step for reacting the void layer with the adhesive layer to form the intermediate layer.

[0097] The void layer formation process (the method for manufacturing the void layer) may further include a gel-like silica synthesis process, a gel pulverization process, and a bonding process. The void layer formation process (the method for manufacturing the void layer of this disclosure) may include other processes besides the gel-like silica synthesis process, the gel pulverization process, and the bonding process, or it may not include them. These other processes are not particularly limited; examples include coating processes and drying processes, which will be described later.

[0098] The gelled silica synthesis process includes, for example, a step of condensing or partially condensing the silane compound to synthesize a gelled silica compound. The gelled silica synthesis process may also include, for example, a step of gelling a blocky porous body in a solvent to form a gel. In this case, for example, in the initial pulverization stage of the pulverization stage in the plurality of stages described later (e.g., the first pulverization stage described later), the gel formed by the gelled silica synthesis process is used.

[0099] The method for manufacturing the void layer includes, for example, a maturation step of maturing the gelled gel in a solvent. In this case, for example, the gel after the maturation step is used in the initial pulverization stage (e.g., the first pulverization stage) of the plurality of pulverization stages.

[0100] The gel pulverization process includes, for example, pulverizing the gel-like silicon compound to obtain pulverized material. The gel pulverization process can be a single stage, but is preferably performed in multiple pulverization stages. The number of pulverization stages is not particularly limited; for example, it can be two stages or more than three stages.

[0101] The volume average particle size of the gel after the first pulverization stage can be, for example, 0.5~100 μm, 1~100 μm, 1~50 μm, 2~20 μm, or 3~10 μm. The volume average particle size of the gel after the second pulverization stage can be, for example, 10~1000 nm, 100~500 nm, or 200~300 nm. The volume average particle size represents the particle size deviation of the pulverized material in the liquid containing the gel (gel-containing liquid). The volume average particle size can be measured, for example, using particle size distribution evaluation devices such as dynamic light scattering and laser diffraction, and electron microscopes such as scanning electron microscope (SEM) and transmission electron microscope (TEM).

[0102] The method for manufacturing the void layer includes, for example, a solvent replacement step after the gel-like silica synthesis step, in which the solvent is replaced with another solvent. In this case, for example, in the initial pulverization stage (e.g., the first pulverization stage) of the plurality of pulverization stages, the gel in the other solvent is used.

[0103] In at least one of the pulverization stages (e.g., at least one of the first pulverization stage and the second pulverization stage) of the plurality of stages in the method for manufacturing the porous layer, the pulverization of the porous body is controlled, for example, while the shear viscosity of the liquid is measured.

[0104] At least one of the crushing stages (e.g., at least one of the first crushing stage and the second crushing stage) in the manufacturing method of the void layer is carried out, for example, by high-pressure medialess crushing.

[0105] It should be noted that, in the following method for manufacturing the void layer, the gel-containing liquid obtained by the process including the gel pulverization step is sometimes simply referred to as "gel-containing liquid".

[0106] According to the gel-containing pulverized liquid, for example, a coating film is formed thereon, and the pulverized material in the coating film is chemically bonded through a bonding process, thereby forming the porous layer as a functional porous body. According to the gel-containing pulverized liquid, the porous layer can be applied to various objects, for example. Therefore, the gel-containing pulverized liquid and its manufacturing method are useful, for example, in the manufacture of the porous layer.

[0107] The gel-containing pulverized liquid has, for example, extremely excellent uniformity, and thus, when the void layer is applied to applications such as optical components, it can achieve a good appearance.

[0108] The gel-containing pulverized liquid may be, for example, a gel-containing pulverized liquid used to obtain a layer (porosity layer) with high porosity by applying (coating) the gel-containing pulverized liquid onto a substrate (coating process) and then drying it (drying process).

[0109] In the coating process, the method for applying the liquid containing gel fragments is not particularly limited, and general coating methods can be used. Examples of such coating methods include slot die coating, reverse gravure coating, microgravure coating, dip coating, spin coating, brush coating, roller coating, flexographic printing, wire rod coating, spray coating, extrusion coating, curtain coating, and reverse coating. From the viewpoints of productivity and coating smoothness, extrusion coating, curtain coating, roller coating, and microgravure coating are preferred. The amount of liquid containing gel fragments applied is not particularly limited; for example, it can be appropriately set in a way that allows for an appropriate thickness of the porous layer. The thickness of the porous layer is not particularly limited, as described above.

[0110] In the drying process, the gel-containing pulverized liquid is dried (i.e., the dispersion medium contained in the gel-containing pulverized liquid is removed) to form the dried coating film (the precursor of the porous layer). The drying temperature in the drying process is, for example, 50–250°C, 60–150°C, or 70–130°C, and the drying time is, for example, 0.1–30 minutes, 0.2–10 minutes, or 0.3–3 minutes. Regarding the drying temperature and time, lower and shorter temperatures are preferred, for example, in relation to continuous production and high porosity performance. If the conditions are too stringent, for example, if the substrate is a resin film, the substrate may stretch in the drying oven due to proximity to the glass transition temperature of the substrate, potentially causing defects such as cracks in the formed porous structure immediately after coating. On the other hand, if the conditions are too lenient, for example, in roll-to-roll processing, residual solvent may be present when the film exits the drying oven, potentially causing scratches or other appearance defects when rubbed against the rollers in the next process.

[0111] The drying method can be, for example, natural drying, heat drying, or vacuum drying. There are no particular limitations on the drying method; for example, common heating methods can be used. The heating unit can be, for example, a hot air blower, a heating roller, or a far-infrared heater. Among these, heat drying is preferred when continuous industrial production is required.

[0112] The bonding process includes a step of chemically bonding the pulverized material. This bonding process can be performed, for example, by irradiating or heating the catalyst or the coating film containing a catalyst generator, which has been pre-added to the liquid containing the gel pulverized material, or by irradiating or heating the coating film after blowing the catalyst, or by irradiating or heating the film while blowing the catalyst or the catalyst generator. The catalyst can be, for example, the crosslinking reaction promoter, or a strength enhancer that improves the strength of the porous layer; the crosslinking promoter can also function as the strength enhancer.

[0113] The cumulative light intensity during the illumination is not particularly limited, but when converted to 360nm, it is, for example, 200~800mJ / cm. 2 250~600mJ / cm 2 or 300~400mJ / cm 2 From the perspective of preventing insufficient irradiation and incomplete decomposition due to light absorption by the catalyst, resulting in insufficient effect, 200 mJ / cm 2 The above cumulative light intensity is sufficient. Furthermore, from the viewpoint of preventing damage to the substrate beneath the void layer and the formation of thermal wrinkles, 800 mJ / cm² is preferred. 2 The following is the cumulative light intensity.

[0114] The heating temperature and heating time are not particularly limited, and the conditions of the heating treatment are not particularly restricted. The heating temperature is, for example, 50–250°C, 60–150°C, or 70–130°C, and the heating time is, for example, 0.1–30 minutes, 0.2–10 minutes, or 0.3–3 minutes. Alternatively, the process of drying the gel-containing pulverized liquid as described above can also be combined with the process of carrying out a chemical reaction in the presence of the catalyst. That is, in the process of drying the coated gel-containing pulverized liquid (e.g., suspension), the pulverized particles can be chemically bonded to each other through a chemical reaction in the presence of the catalyst. In this case, the pulverized particles (microporous particles) can also be more firmly bonded to each other by further heating the coating film after the drying process. It is further speculated that the chemical reaction in the presence of the catalyst may sometimes occur in the process of preparing the microporous particle-containing liquid (e.g., suspension) and in the process of coating the microporous particle-containing liquid. However, this speculation does not limit this disclosure in any way.

[0115] The adhesive layer forming process may include, for example, an adhesive coating process of applying the adhesive coating liquid to a substrate, and a heat drying process of heating and drying the substrate coated with the adhesive coating liquid. For example, the adhesive layer can be formed on the void layer by attaching the adhesive layer side of an adhesive tape or similar material, on which the adhesive layer is laminated, to the void layer. In this case, the adhesive tape or similar material can be directly attached or peeled off from the adhesive layer. In particular, by peeling off the material to form a substrate-free (substrate-free) laminate, the thickness can be significantly reduced, and the thickness increase of the device or the like can be suppressed. In this disclosure, the adhesive layer can be manufactured using the adhesive coating liquid, for example, as described above.

[0116] The adhesive layer forming process can be performed as follows: First, the adhesive coating liquid is manufactured by a mixing process in which all components of the adhesive coating liquid are mixed. The adhesive coating liquid may, for example, contain a (meth)acrylic polymer, and may further contain, for example, a crosslinking agent (e.g., an isocyanate-based crosslinking agent, an epoxy-based crosslinking agent), or may not contain any of these. The adhesive coating liquid may, for example, contain the (meth)acrylic polymer, a monomer having one or two reactive double bonds in one molecule, a crosslinking agent, and an organic peroxide. In this case, if the adhesive coating liquid contains other components, these other components may also be mixed together. For example, the polymerization solvent used in the manufacture of the (meth)acrylic polymer may not be removed, and the mixture may be directly used as a component of the adhesive coating liquid. Furthermore, the method for manufacturing the adhesive coating liquid may include other processes besides the mixing process, or may not include them; all components of the adhesive coating liquid may be mixed solely through the mixing process.

[0117] Next, the adhesive coating liquid is applied to the substrate (adhesive coating liquid application step). The substrate is not particularly limited and can be, for example, a film or similar material. The substrate is preferably made of thermoplastic resin, glass, inorganic substrates such as silicon, plastics molded from thermosetting resins, semiconductors, carbon fiber materials such as carbon nanotubes, etc., but is not limited to these. The substrate can take the form of a film or sheet. Examples of thermoplastic resins include polyethylene terephthalate (PET), acrylic resins, cellulose acetate propionate (CAP), cyclic olefin polymers (COP), triacetyl cellulose (TAC), polyethylene naphthalate (PEN), polyethylene (PE), and polypropylene (PP). Furthermore, the coating thickness of the adhesive coating liquid in the adhesive coating liquid application step is not particularly limited; it can be adjusted appropriately, for example, to achieve a predetermined thickness for the dried adhesive layer. The thickness of the dried adhesive layer is also not particularly limited, as will be described later.

[0118] Next, the substrate coated with the adhesive liquid is heated and dried (heat drying step). In this heat drying step, the heating and drying temperature is not particularly limited, and can be, for example, 50°C or higher, 80°C or higher, 100°C or higher, or 155°C or higher, or, for example, below 200°C, below 180°C, or below 160°C. The heating and drying time is not particularly limited, and can be, for example, 0.5 minutes or more, 1 minute or more, or 3 minutes or more, or, for example, below 60 minutes, below 30 minutes, below 20 minutes, or below 10 minutes. In this heat drying step, for example, a crosslinking reaction and graft polymerization occur between the (meth)acrylic polymer and the crosslinking agent. Thus, for example, as described above, the amount of semi-polymer present in the adhesive liquid is reduced, making it difficult for the adhesive layer to penetrate into the recess of the first optical sheet. By operating as described above, the adhesive layer used in the laminate of this disclosure can be manufactured.

[0119] Next, as described above, the adhesive layer is bonded to the void layer (bonding process). This method is not particularly limited; for example, as described above, the adhesive layer can be formed on the void layer by bonding the adhesive layer side, such as an adhesive tape on which the adhesive layer of the present disclosure is laminated on a substrate, to the void layer. As described above, the laminate of the present disclosure can be manufactured.

[0120] The thickness of the adhesive layer is not particularly limited, for example, it is 0.1~100μm, 5~50μm, 10~30μm or 12~25μm.

[0121] In the method for manufacturing the laminate disclosed herein, a heating step may be performed, for example, after the bonding step, to heat the adhesive layer and the void layer. Hereinafter, this heating step is sometimes referred to as an "aging step." In this heating step (aging step), the heating temperature is not particularly limited, and may be, for example, 40°C or higher, 45°C or higher, or 50°C or higher, or, for example, 80°C or lower, 70°C or lower, 60°C or lower, or 55°C or lower. The heating time is not particularly limited, and may be, for example, 1 minute or more, 10 minutes or more, 60 minutes or more, or 1800 minutes or more, or, for example, 3000 minutes or lower, 2800 minutes or lower, 2500 minutes or lower, or 2000 minutes or lower. In this aging step, for example, the intermediate layer is formed by the bonding of the void layer and the adhesive layer. Moreover, for example, the intermediate layer acts as a barrier layer, which can suppress the reduction in porosity caused by the adhesive filling the voids in the void layer. It should be noted that the combination of the void layer and the adhesive layer can be either the adhesive layer being embedded in the voids of the void layer and chemically bonded, or the adhesive layer being embedded in the voids of the void layer.

[0122] The adhesive layer protects the void layer from physical damage (especially abrasions). Furthermore, even when using an adhesive layer that is a substrate-free adhesive sheet containing a void layer, a sheet with excellent pressure resistance is preferred to prevent the void layer from being flattened; there are no particular limitations.

[0123] The laminate obtained in this way, as described above, can be further laminated with other films (layers) to form a laminated structure containing the void layer (porous structure). In this case, the constituent elements in the aforementioned laminated structure can be laminated, for example, via the aforementioned adhesive layer (adhesive or bonding agent).

[0124] From an efficiency standpoint, the stacking of the constituent elements can be performed by using continuous processing of long strip films (such as roll-to-roll), and when the substrate is a molded object, component, etc., the substrate that has been processed in batches can be stacked.

[0125] [3. Optical Components]

[0126] As described above, the optical component of this disclosure comprises the laminate of this disclosure. The optical component of this disclosure is characterized by comprising the laminate of this disclosure, while there are no other limitations on its composition. The optical component of this disclosure may, for example, comprise other layers besides the laminate. The optical component of this disclosure may, for example, be in a roll form.

[0127] [4. Optical Devices]

[0128] As described above, the optical device disclosed herein includes the optical components disclosed herein. The optical device disclosed herein is not particularly limited; for example, it may be an image display device or an illumination device. Examples of image display devices include liquid crystal displays, organic EL (Electroluminescence) displays, and micro LED (Light Emitting Diode) displays. Examples of illumination devices include organic EL lighting.

[0129] Example

[0130] Next, embodiments of the present disclosure will be described. However, the present disclosure is not limited to the following embodiments.

[0131] It should be noted that, in the following reference examples, embodiments, and comparative examples, the parts (relative amounts) of each substance are parts by mass (parts by weight) unless otherwise specified. In the following reference examples, embodiments, and comparative examples, the adhesive (adhesive composition) described later is used as the adhesive. In the following reference examples, embodiments, and comparative examples, "adhesive layer" is equivalent to "adhesive bonding layer." That is, in the following reference examples, embodiments, and comparative examples, unless otherwise specified, "adhesive layer" and "adhesive bonding layer" have the same meaning.

[0132] In addition, in the following reference examples, embodiments and comparative examples, the nanoindentation hardness, the refractive index of the void layer (in the laminated state) and the refractive index (void layer) when only the void layer is measured, the peel strength and the void retention rate are measured by the methods described in the embodiments.

[0133] It should be noted that in the adhesive layers of the following reference examples, embodiments and comparative examples, it is speculated that the polymer (acrylic polymer) is cross-linked by the cross-linking agent and forms a cross-linked structure by heating and drying the coated adhesive, but the cross-linked structure has not been confirmed.

[0134] [Reference Example 1: Formation of the adhesive layer (adhesive 1)]

[0135] The adhesive layer of this reference example (reference example 1) is formed by the following steps (1) to (3).

[0136] (1) Preparation of acrylic polymer solutions

[0137] In a four-necked flask equipped with a stirring blade, thermometer, nitrogen inlet tube, and condenser, 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, and 0.1 parts by weight of 2,2'-azobisisobutyronitrile (2,2'-Azobisisobutyronitrile) as a polymerization initiator were added along with 100g of ethyl acetate. Then, nitrogen gas was introduced to purge the contents of the four-necked flask while stirring slowly. The liquid temperature in the four-necked flask was then maintained at approximately 55°C for 8 hours to prepare an acrylic polymer solution.

[0138] (2) Preparation of acrylic adhesive compositions

[0139] Acrylic adhesive composition (acrylic adhesive solution) is prepared by combining 100 parts of the solid component of the acrylic polymer solution obtained in (1) with 0.2 parts of isocyanate crosslinking agent (commercial name "CORONATE L" manufactured by Nippon Polyurethane Industries Co., Ltd., an adduct of trimethylolpropane toluene diisocyanate), 0.3 parts of benzoyl peroxide (commercial name "NYPER BMT" manufactured by Nippon Oils & Fats Co., Ltd.), and 0.1 parts of γ-epoxypropoxypropylmethoxysilane (commercial name "KBM-403" manufactured by Shin-Etsu Chemical Co., Ltd.).

[0140] (3) Formation of adhesive layer

[0141] The acrylic adhesive composition obtained in (2) is coated on one side of a silicone-treated polyethylene terephthalate (PET) film (manufactured by Mitsubishi Chemical Polyester Film Co., Ltd., thickness: 38 μm) with a dried adhesive layer thickness of 10 μm, and dried at 150°C for 3 minutes to form adhesive 1 as an adhesive layer (adhesive bonding layer).

[0142] [Reference Example 2: Formation of the adhesive layer (adhesive 2)]

[0143] The adhesive layer of this reference example (reference example 2) is formed by the following steps (1) to (3).

[0144] (1) Preparation of (meth)acrylic acid polymer (A1) solution

[0145] A monomer mixture containing 79.5 parts butyl acrylate, 15 parts N-acryloylmorpholine, 5 parts acrylic acid, and 0.5 parts 4-hydroxybutyl acrylate was added to a four-necked flask equipped with a stirring blade, thermometer, nitrogen inlet pipe, and condenser. Then, relative to 100 parts of the monomer mixture, 0.1 parts 2,2'-azobisisobutyronitrile and 70 parts ethyl acetate were added as polymerization initiators. After nitrogen purging by slowly stirring, the liquid temperature in the flask was maintained at approximately 55°C for 2 hours to prepare a solution of a (meth)acrylic acid polymer (A1) with a weight-average molecular weight (Mw) of 3 million and Mw / Mn = 2.5.

[0146] (2) Preparation of (meth)acrylic adhesive compositions

[0147] A solution of an acrylic adhesive composition was prepared by mixing 100 parts of the solid component of the obtained (meth)acrylic polymer (A1) solution with 0.2 parts of isocyanate crosslinking agent (commercial name "CORONATE L" manufactured by Nippon Polyurethane Industry Co., Ltd., an adduct of trimethylolpropane toluene diisocyanate) and 0.2 parts of epoxy crosslinking agent 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane (commercial name "TETRAD C" manufactured by Mitsubishi Gas Chemical Co., Ltd.).

[0148] (3) Formation of adhesive layer

[0149] Next, a solution of the acrylic adhesive composition is applied to one side of a polyethylene terephthalate film (release film: manufactured by Mitsubishi Chemical Polyester Film Co., Ltd., MRF38) treated with an organosilicon release agent, such that the thickness of the dried adhesive layer is 10 μm. The film is then dried at 155°C for 1 minute to form adhesive 2 as an adhesive layer (adhesive bonding layer) on the surface of the release film.

[0150] [Reference Example 3: Formation of the adhesive layer (adhesive 3)]

[0151] The adhesive layer of this reference example (reference example 3) is formed by the following steps (1) to (3).

[0152] (1) Preparation of acrylic polymer solutions

[0153] In a four-necked flask equipped with a stirring blade, thermometer, nitrogen inlet pipe, and condenser, 99 parts of butyl acrylate, 1 part of 4-hydroxybutyl acrylate, and 0.1 parts of 2,2'-azobisisobutyronitrile (2,2'-Azobisisobutyronitrile) as a polymerization initiator were added along with 100 parts of ethyl acetate. Then, nitrogen gas was introduced to purge the contents of the flask while stirring slowly. The liquid temperature in the flask was then maintained at approximately 55°C for 8 hours to prepare a solution of acrylic polymer.

[0154] (2) Preparation of acrylic adhesive compositions

[0155] A solution of an acrylic adhesive composition is prepared by combining 100 parts of the solid component of the acrylic polymer solution obtained in (1) with 0.1 parts of isocyanate crosslinking agent (trade name "TAKENATED110N" manufactured by Mitsui Takeda Chemical Co., Ltd., trimethylolpropane dimethyl diisocyanate), 0.1 parts of benzoyl peroxide (trade name "NYPER BMT" manufactured by Nippon Oils & Fats Co., Ltd.), and 0.2 parts of γ-epoxypropoxypropylmethoxysilane (trade name "KBM-403" manufactured by Shin-Etsu Chemical Co., Ltd.).

[0156] (3) Formation of adhesive layer

[0157] The solution of the acrylic adhesive composition obtained in (2) is applied to one side of a polyethylene terephthalate film (release film: manufactured by Mitsubishi Chemical Polyester Film Co., Ltd., trade name "MRF38") treated with an organosilicon release agent, and dried at 150°C for 3 minutes to form an adhesive 3 with a thickness of 20 μm as an adhesive layer (adhesive bonding layer) on the surface of the release film.

[0158] [Examples 1-9, Comparative Examples 1-3: Fabrication of Laminated Composites]

[0159] The laminates of Examples 1-9 and Comparative Examples 1-3 were manufactured using the following methods.

[0160] (Example 1)

[0161] (1) Gel formation of silicon compounds (synthesis process of gel-like silica)

[0162] Mixture A was prepared by dissolving 1.90 g of methyltrimethoxysilane (MTMS) and 0.1 g of tetraethoxysilane (TEOS), precursors of silicon compounds, in 4.4 g of dimethyl sulfoxide (DMSO). 1.0 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 and tetra(hydroxy)silane. Mixture B was further added to 5.5 g of DMSO with 0.38 g of 28% by weight ammonia and 0.2 g of pure water, and stirred at room temperature for 15 minutes to gel the tri(hydroxy)methylsilane and tetra(hydroxy)silane, yielding mixture C containing a gel-like silicon compound.

[0163] (2) Aging treatment

[0164] The mixture C containing the gel-like silicon compound prepared as described above was directly incubated at 40°C for 20 hours for aging treatment.

[0165] (3) Pulverization process (gel pulverization process)

[0166] Next, the gel-like silicon compound, which had undergone the curing treatment as described above, was pulverized into particles ranging from several millimeters to several centimeters in size using a spatula. Then, 40 g of isopropanol (IPA) was added to mixture C, and after gentle stirring, the mixture was allowed to stand at room temperature for 6 hours. The solvent and catalyst in the gel were then decanted. Solvent displacement was performed by repeating the same decantation 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"). 1.85 g of the gel-like compound and 1.15 g of IPA from mixture D were weighed into a 5 cc screw-top bottle, and pulverized for 2 minutes at 50 W and 20 kHz.

[0167] Through this pulverization process, the gel-like silicon compound in the above-mentioned mixture D is pulverized, thereby mixture D becomes a sol solution E of pulverized material. The volume average particle size, which represents the particle size deviation of the pulverized material contained in sol solution E, was confirmed using a dynamic light scattering Nanotrac particle size analyzer (Nikko Pure Chemical Industries, Ltd., UPA-EX150 model), and the result was 0.50~0.70 μm. Furthermore, for 0.75 g of sol solution E, 0.124 g of a 1.5 wt% MEK (methyl ethyl ketone) solution of a photoalkali-generating agent (Wako Pure Chemical Industries, Ltd., trade name: WPBG266) as a precursor for crosslinking reaction promotion was added, along with 0.036 g of a 5 wt% MEK solution of a crosslinking aid (bis(trimethoxysilyl)hexane), to obtain a coating solution 1 for forming a low refractive index layer.

[0168] A low-refractive-index layer forming coating solution was applied to an acrylic substrate and dried to form a porous layer with a thickness of approximately 850 nm (porosity 59% by volume). Alternatively, coating was performed using a wire rod, with a drying temperature of 100°C and a drying time of 2 minutes. Next, the porous layer was subjected to UV irradiation (300 mJ) to bond the fragments of the gel-like compound together (bonding process). It should be noted that the bonding of the fragments of the gel-like compound in the bonding process presumably includes at least one of crosslinking bonds (covalent bonds) directly bonded to each other without a crosslinking aid, and crosslinking bonds (covalent bonds) formed via a crosslinking aid. Then, a 10 μm thick adhesive 1 was bonded to the porous layer and cured at 50°C for 30 hours to produce the porous layer of this embodiment. Furthermore, the manufactured porous layer was used to manufacture the laminate of this embodiment.

[0169] (Example 2)

[0170] The amounts of the photoalkali-generating agent and crosslinking aid in Example 1 were changed to a ratio of 0.186 g of a 1.5% by weight MEK (methyl ethyl ketone) solution of the photoalkali-generating agent (Wako Pure Chemical Industries, Ltd., trade name: WPBG 266) and 0.054 g of a 5% by weight MEK solution of the crosslinking aid (1,6-bis(trimethoxysilyl)hexane) relative to 0.75 g of sol solution E. Otherwise, the same operation as in Example 1 was performed to manufacture the void layer of this embodiment. Furthermore, the manufactured void layer was used to manufacture the laminate of this embodiment.

[0171] (Example 3)

[0172] The amount of tetraethoxysilane (TEOS) added in Example 1 was changed to 0.2g, and the laminate of this example was manufactured by performing the same operation as in Example 1.

[0173] (Example 4)

[0174] The amount of tetraethoxysilane (TEOS) added in Example 1 was changed to 0.2g, and the same operation as in Example 2 was performed to manufacture the void layer of this embodiment. Furthermore, the manufactured void layer was used to manufacture the laminate of this embodiment.

[0175] (Example 5)

[0176] Instead of adhesive 1 used in Example 1, adhesive 2 is used, and the same operations as in Example 1 are performed to manufacture the void layer of this embodiment. Furthermore, the manufactured void layer is used to manufacture the laminate of this embodiment.

[0177] (Example 6)

[0178] The amount of tetraethoxysilane (TEOS) added in Example 1 was changed to 0.3g, and the same operation as in Example 1 was performed to manufacture the void layer of this embodiment. Furthermore, the manufactured void layer was used to manufacture the laminate of this embodiment.

[0179] (Example 7)

[0180] The amount of tetraethoxysilane (TEOS) added in Example 1 was changed to 0.4 g, and the same operation as in Example 1 was performed to manufacture the void layer of this embodiment. Furthermore, the manufactured void layer was used to manufacture the laminate of this embodiment.

[0181] (Example 8)

[0182] In Example 1, 0.95 g of methyltrimethoxysilane (MTMS), a precursor of the silicon compound, was dissolved in 2.2 g of dimethyl sulfoxide (DMSO), without adding tetramethoxysilane (TMOS). Otherwise, the same operation as in Example 1 was performed to manufacture the laminate of this example.

[0183] (Example 9)

[0184] The amount of tetraethoxysilane (TEOS) added in Example 1 was changed to 0.2 g, and the amounts of photoalkalizing agent and crosslinking aid added were changed to 0.062 g of a 1.5 wt% MEK (methyl ethyl ketone) solution of photoalkalizing agent (Wako Pure Chemical Industries, Ltd., trade name: WPBG266) and 0.018 g of a 5 wt% MEK solution of crosslinking aid (bis(trimethoxysilyl)hexane) relative to 0.75 g of sol solution E. Otherwise, the same operation as in Example 1 was performed to manufacture the void layer of this embodiment. Furthermore, the manufactured void layer was used to manufacture the laminate of this embodiment.

[0185] (Comparative Example 1)

[0186] In Example 9, tetraethoxysilane (TEOS) was not added, but the same procedures as in Example 9 were performed to manufacture the void layer of this comparative example. Furthermore, the manufactured void layer was used to manufacture the laminate of this comparative example.

[0187] (Comparative Example 2)

[0188] Instead of adhesive 1 used in Comparative Example 1, adhesive 2 was used, and the same operation as in Comparative Example 1 was performed to manufacture the void layer of this Comparative Example. Furthermore, the manufactured void layer was used to manufacture the laminate of this Comparative Example.

[0189] (Comparative Example 3)

[0190] Instead of adhesive 1 used in Comparative Example 1, adhesive 3 was used, and the same operation as in Comparative Example 1 was performed to manufacture the void layer of this Comparative Example. Furthermore, the manufactured void layer was used to manufacture the laminate of this Comparative Example.

[0191] [Table 1]

[0192]

[0193] As shown in Table 1, the interlayer peel strength of the laminates in the embodiments is 3 N / 25 mm or more, which is good. On the other hand, the interlayer peel strength of the laminates in the comparative examples is less than 3 N / 25 mm.

[0194] in addition, Figure 4The figure shows the relationship between peel strength and refractive index for examples and comparative examples where the nanoindentation hardness is 0.5 MPa or higher when forming the laminate. Figure 4 In the above, the formula "Y = 80.409x - 93.718" is a linear function taking the average of two points from Comparative Example 1 and Example 8, where the addition of the trifunctional silane compound was not combined with the trifunctional silane compound and only the addition of the substances that generate crosslinking aids and crosslinking reaction promoters was changed. The formula "Y = 136.4x - 159.92" is a linear function taking the average of two points from Examples 1 and 2, where the addition of the trifunctional silane compound was combined with 3.5 mol% of the trifunctional silane compound and only the addition of the substances that generate crosslinking aids and crosslinking reaction promoters was changed. The formula "Y = 141.37x - 165.06" is a linear function taking the average of three points from Examples 3, 4, and 9, where the addition of the trifunctional silane compound was combined with 6.9 mol% of the trifunctional silane compound and only the addition of the substances that generate crosslinking aids and crosslinking reaction promoters was changed.

[0195] like Figure 4 As shown, in all embodiments, the peel strength between the void layer and the adhesive layer is 3 N / 25 mm or more. Furthermore, the laminates in all embodiments satisfy condition (1) (Y ≥ 80X - 93.8) described in the embodiment. It can be further seen that the laminates in the embodiments, by including a tetrafunctional silane compound as the silane compound, exhibit greater peel strength compared to void layers that do not contain a tetrafunctional silane compound having the same refractive index. That is, they satisfy condition (2) (Y ≥ 100X - 117) described in the embodiment. Furthermore, by increasing the proportion of the crosslinking aid and the crosslinking reaction promoter (the precursor of the crosslinking reaction promoter), the peel strength is further improved.

[0196] This disclosure may also be described, for example, as in the following notes. However, the following notes are examples, and this disclosure is not limited to these methods.

[0197] (Note 1) A laminate comprising a void layer and an adhesive layer, wherein the adhesive layer is directly laminated on one or both sides of the void layer, wherein the refractive index of the void layer, as measured in the laminated state, is less than 1.30, the nanoindentation hardness, as measured by pressing an indenter into the adhesive layer at a depth of 2000 nm using a nanoindenter, is greater than 0.5 MPa, and the peel strength between the void layer and the adhesive layer, as measured by a tensile testing machine at a tensile speed of 0.3 m / min, is greater than 3 N / 25 mm.

[0198] (Note 2) The laminate according to Note 1, wherein the peel strength is 3.5 N / 25 mm or more.

[0199] (Note 3) The laminate according to Note 1 or 2, wherein the refractive index is less than 1.25.

[0200] (Note 4) The laminate according to any one of Notes 1 to 3, wherein when the refractive index is set to X and the peel strength is set to Y, the following condition (1) is satisfied.

[0201] Condition (1): Y ≥ 80X - 93.8

[0202] (Note 5) The laminate according to any one of Notes 1 to 3, wherein when the refractive index is set to X and the peel strength is set to Y, the following condition (2) is satisfied.

[0203] Condition (2): Y≥100X-117

[0204] (Note 6) The laminate according to any one of Notes 1 to 5, wherein the nanoindentation hardness is 1.2 MPa or less.

[0205] (Note 7) The laminate according to any one of Notes 1 to 6, wherein after a heat and humidity durability test at a temperature of 85°C and a humidity of 85%RH for 500 hours, the porosity of the void layer is 10% by volume or more.

[0206] (Note 8) The laminate according to any one of Notes 1 to 7, wherein there is an intermediate layer between the void layer and the adhesive layer, the intermediate layer being a layer formed by combining the void layer and the adhesive layer.

[0207] (Note 9) The laminate according to any one of Notes 1 to 8, wherein the void layer comprises a compound formed by the condensation or partial condensation of a silane compound.

[0208] (Note 10) The laminate according to Note 9, wherein the silane compound comprises 1-3 functional silane compounds and 4 functional silane compounds.

[0209] (Note 11) According to the laminate described in Note 10, the content ratio of the 4-functional silane compound to the 1-3 functional silane compound is 1-25 mol%.

[0210] (Note 12) The laminate according to any one of Notes 9 to 11, wherein the void layer is a void layer chemically bonded to a powder of a gel-like silicon compound, the powder of the gel-like silicon compound being a compound formed by the condensation or partial condensation of the silane compound.

[0211] (Note 13) According to the laminate described in Note 12, wherein the void layer is a void layer formed by chemical bonding of pulverized gel-like silicon compounds under the coexistence of additives, wherein the additives include at least one of a crosslinking reaction promoter and a precursor thereof, the precursor being a substance that generates the crosslinking reaction promoter by light or heat.

[0212] (Note 14) The laminate according to Note 13, wherein the crosslinking reaction promoter is an acidic or basic substance.

[0213] (Note 15) According to the laminate described in Note 13 or 14, the total content of the crosslinking reaction promoter and its precursor is 1 mol% or more relative to the total mass of the 1-3 functional silane compounds and the 4 functional silane compounds.

[0214] (Note 16) The laminate according to any one of Notes 12 to 15, wherein the void layer is a void layer formed by chemical bonding of the pulverized gel-like silicon compound under the coexistence of the additive, and the additive includes a crosslinking aid.

[0215] (Note 17) According to the laminate described in Note 16, the total content of the crosslinking aid is 1 mol% or more relative to the total mass of the 1-3 functional silane compounds and the 4 functional silane compounds.

[0216] (Appendix 18) The laminate according to any one of Appendices 1 to 8, wherein the void layer is a void layer formed by chemical bonding of pulverized gel-like silicon compound under the coexistence of additives, the gel-like silicon compound being a compound formed by the condensation or partial condensation of silane compounds, the additive comprising at least one of a crosslinking reaction promoter and its precursor, and a crosslinking aid, wherein the total content of the crosslinking reaction promoter and its precursor is 1.5 mol% or more relative to the total mass of the silane compound, and the total content of the crosslinking aid is 2.0 mol% or more.

[0217] (Note 19) A method for manufacturing a laminate, which is the method for manufacturing a laminate as described in any one of Notes 1 to 18, comprising: a void layer forming step for forming the void layer, and an adhesive layer forming step for forming the adhesive layer on the void layer.

[0218] (Appendix 20) According to the method for manufacturing the laminate described in Appendix 19, the void layer forming step further includes a gel-like silica synthesis step, a gel pulverization step, and a bonding step. The gel-like silica synthesis step includes a step of condensing or partially condensing a silane compound to synthesize a gel-like silicon compound. The silane compound includes 1-3 functional silane compounds and 4 functional silane compounds. The gel pulverization step includes a step of pulverizing the gel-like silicon compound to obtain a pulverized material. The bonding step includes a step of chemically bonding the pulverized material.

[0219] (Appendix 21) According to the method for manufacturing the laminate as described in Appendix 19, the void layer forming step further includes a gel-like silica synthesis step, a gel pulverization step, and a bonding step. The gel-like silica synthesis step includes a step of condensing or partially condensing a silane compound to synthesize a gel-like silicon compound. The gel pulverization step includes a step of pulverizing the gel-like silicon compound to obtain a pulverized material. The bonding step includes a step of chemically bonding the pulverized material under the coexistence of additives. The additives include at least one of a crosslinking reaction promoter and its precursor, and a crosslinking aid.

[0220] (Note 22) An optical component comprising the laminate as described in any one of Notes 1 to 18.

[0221] (Note 23) An optical device comprising the optical components described in Note 22.

[0222] (Note 24) The optical device according to Note 23, wherein the device is an image display device or an illumination device.

[0223] Industrial availability

[0224] As described above, according to this disclosure, laminates, optical components, and optical devices with low refractive index and excellent mechanical strength can be provided. The applications of this disclosure are not particularly limited. For example, the optical devices of this disclosure are not particularly limited and can include image display devices, lighting devices, etc. Examples of image display devices include liquid crystal displays, organic EL displays, and micro LED displays. Examples of lighting devices include organic EL lighting. Furthermore, the applications of the laminates of this disclosure are not limited to the optical components and optical devices of this disclosure; they are arbitrary and can be used in a wide range of applications.

[0225] This application claims priority based on Japanese Application Special Hoc 2023-107488, filed on June 29, 2023, the entire disclosure of which is incorporated herein by reference.

[0226] Explanation of reference numerals in the attached figures

[0227] 10, 10a, 10b, 10c, 10d, 10e: Laminated structures

[0228] 11: Porous layer

[0229] 12: Adhesive layer

[0230] 13: Intermediate layer

[0231] 14: Substrate

Claims

1. A laminate characterized in that, the laminate comprises a void layer and an adhesive bonding layer, the adhesive bonding layer is directly laminated to one side or both sides of the void layer, a refractive index of the void layer measured in a state of the laminate is 1.30 or less, a nanoindentation hardness measured by pressing an indenter into the adhesive bonding layer by 2000 nm using a nanoindenter is 0.5 MPa or more, a peeling strength between the void layer and the adhesive bonding layer measured using a tensile testing machine at a tensile speed of 0.3 m / min is 3 N / 25 mm or more.

2. The laminate according to claim 1, characterized in that, the peeling strength is 3.5 N / 25 mm or more.

3. The laminate according to claim 1, characterized in that, the refractive index is 1.25 or less.

4. The laminate according to claim 1, characterized in that, when the refractive index is set as X and the peeling strength is set as Y, the following condition (1) is satisfied, condition (1): Y ≥ 80X - 93.

8.

5. The laminate according to claim 1, characterized in that, when the refractive index is set as X and the peeling strength is set as Y, the following condition (2) is satisfied, condition (2): Y ≥ 100X - 117.

6. The laminate according to claim 1, characterized in that, the nanoindentation hardness is 1.2 MPa or less.

7. The laminate according to claim 1, characterized in that, after a heat and humidity durability test in which the temperature is 85°C and the humidity is 85% RH for 500 hours, a void residual rate of the void layer is 10% by volume or more.

8. The laminate according to claim 1, characterized in that, an intermediate layer is present between the void layer and the adhesive bonding layer, the intermediate layer is a layer formed by the void layer and the adhesive bonding layer being combined.

9. The laminate according to claim 1, characterized in that, the void layer comprises a compound obtained by condensation or partial condensation of a silane compound.

10. The laminate according to claim 9, characterized in that, as the silane compound, a 1-3 functional silane compound and a 4 functional silane compound are contained.

11. The laminate according to claim 10, characterized in that, a contained proportion of the 4 functional silane compound with respect to a mass of the 1-3 functional silane compound is 1-25 mol%.

12. The laminate according to claim 9, characterized in that, the void layer is a void layer in which a pulverized product of a gel-like silicon compound is chemically bonded, the pulverized product of the gel-like silicon compound is a compound obtained by condensation or partial condensation of the silane compound.

13. The laminate according to claim 12, characterized in that, the void layer is a void layer in which the pulverized product of the gel-like silicon compound is chemically bonded in the presence of an additive, as the additive, at least one of a crosslinking reaction promoter and a precursor thereof is contained, the precursor is a substance that generates the crosslinking reaction promoter by light or heat.

14. The laminate according to claim 13, characterized in that, The cross-linking reaction promoter is an acidic substance or a basic substance.

15. The laminate according to claim 12, wherein The void layer is a void layer in which the pulverized product of the gel-like silicon compound is chemically bonded in the presence of an additive, As the additive, a cross-linking auxiliary agent is included.

16. An optical member, comprising: The laminate according to any one of claims 1 to 15.

17. An optical device, comprising: The optical member according to claim 16.

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