Void-provided layer, method for producing void-provided layer, laminate, optical member, and optical device

Abstract

To provide a void layer having a low refractive index and excellent mechanical strength.SOLUTION: The void-provided layer 11 according to the present disclosure is a void-provided layer to which pulverized products of a gelled silicon compound are chemically bonded, the gelled silicon compound is a compound obtained by condensation or partial condensation of a silane compound, the silane compound includes a mono - to tri-functional silane compound and a tetra-functional silane compound, and the refractive index of the void-provided layer 11 is 1.30 or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a gap layer, a method for manufacturing a gap layer, a laminate, an optical member, and an optical device. [Background technology]

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

[0003] [Patent Document 1] Japanese Patent Application Publication No. 10-62626 Summary of the Invention [Problem to be solved by the invention]

[0004] As mentioned above, a gap layer is a layer having voids. Generally, the refractive index of a gap layer tends to be lower as the porosity of the gap layer increases. On the other hand, when the porosity of a gap layer is increased, the mechanical strength of the gap layer tends to be lower. In other words, there is a trade-off between the refractive index of a gap layer and the mechanical strength of the gap layer. Therefore, it is desirable to realize a gap layer that has high mechanical strength even if it has a low refractive index.

[0005] Therefore, an object of the present disclosure is to provide a gap layer that has a low refractive index and excellent mechanical strength, a method for manufacturing a gap layer, a laminate, an optical member, and an optical device. [Means for solving the problem]

[0006] In order to achieve the above object, the air gap layer of the present disclosure is It is a porous layer in which pulverized gel silicon compound is chemically bonded, The gel silicon compound is a compound obtained by condensing or partially condensing a silane compound, The silane compound includes a monofunctional to trifunctional silane compound and a tetrafunctional silane compound, The refractive index of the air gap layer is 1.30 or less.

[0007] The air gap layer of the present disclosure is It is a porous layer in which pulverized gel silicon compound particles are chemically bonded in the presence of additives, The gel silicon compound is a compound obtained by condensing or partially condensing a silane compound, The additives include at least one of a crosslinking reaction accelerator and a precursor thereof, and a crosslinking auxiliary; With respect to the total amount of the silane compounds, the total content of the crosslinking reaction accelerator and its precursor is 1.5 mol% or more, The total content of the crosslinking auxiliary agent is 2.0 mol% or more, The refractive index of the air gap layer is 1.30 or less.

[0008] The method for producing the air gap layer according to the present disclosure includes: The method includes a gel silica synthesis step, a gel crushing step, and a bonding step, the gel silica synthesis step includes a step of synthesizing a gel silicon compound by condensing or partially condensing a silane compound, The silane compound includes a monofunctional to trifunctional silane compound and a tetrafunctional silane compound, The gel-crushing step includes a step of crushing the gel silicon compound to obtain a crushed product, The bonding step includes a step of chemically bonding the pulverized material.

[0009] The method for producing the air gap layer according to the present disclosure includes: The method includes a gel silica synthesis step, a gel crushing step, and a bonding step, the gel silica synthesis step includes a step of synthesizing a gel silicon compound by condensing or partially condensing a silane compound, The gel-crushing step includes a step of crushing the gel silicon compound to obtain a crushed product, The bonding step includes a step of chemically bonding the pulverized material in the presence of an additive, The additives include at least one of a crosslinking reaction accelerator and a precursor thereof, and a crosslinking auxiliary.

[0010] The laminate of the present disclosure comprises: The porous layer of the present disclosure and an adhesive layer are included, The adhesive layer is directly laminated on one or both sides of the porous layer.

[0011] The optical member of the present disclosure includes the air gap layer of the present disclosure or the laminate of the present disclosure.

[0012] The optical device of the present disclosure includes the optical member of the present disclosure. [Effects of the Invention]

[0013] According to the present disclosure, it is possible to provide a gap layer having a low refractive index and excellent mechanical strength, a method for manufacturing a gap layer, a laminate, an optical member, and an optical device. [Brief explanation of the drawings]

[0014] [Figure 1] 1(a) and (b) are cross-sectional views illustrating the configuration of a laminate according to the present disclosure. [Figure 2] 2(a) and (b) are cross-sectional views showing other examples of the configuration of the laminate of the present disclosure. [Figure 3] 3(a) and (b) are cross-sectional views showing still another example of the configuration of the laminate of the present disclosure. [Figure 4] FIG. 4 is a graph showing the relationship between peel strength and refractive index. DETAILED DESCRIPTION OF THE INVENTION

[0015] Next, the present disclosure will be described in more detail using examples, but the present disclosure is not limited to the following description.

[0016] In the present disclosure, the term "adhesive layer" refers to a layer formed of at least one of a pressure-sensitive adhesive and an adhesive. In the present disclosure, unless otherwise specified, the term "adhesive layer" may refer to a "pressure-sensitive adhesive layer" formed of a pressure-sensitive adhesive, an "adhesive layer" formed of an adhesive, or a layer containing both a pressure-sensitive adhesive and an adhesive. Furthermore, in the present disclosure, pressure-sensitive adhesives and adhesives may be collectively referred to as "adhesive adhesives." Generally, a material with relatively weak adhesive or bonding strength (e.g., a material that allows for re-detachment from an adherend) is sometimes referred to as a "pressure-sensitive adhesive," while a material with relatively strong adhesive or bonding strength (e.g., a material that is impossible or extremely difficult to re-detach from an adherend) is sometimes referred to as an "adhesive." In the present disclosure, there is no clear distinction between a pressure-sensitive adhesive and an adhesive. Furthermore, in the present disclosure, there is no clear distinction between "adhesive strength" and "adhesive strength."

[0017] In the present disclosure, "on" or "on the surface" may refer to a state of being in direct contact with the surface or a state of being interposed between another layer or the like.

[0018] In the present disclosure, "interlayer" refers to any part between one layer and another layer, including the one layer and the other layer. That is, for example, when referring to the interlayer between one layer and another layer, it may refer to any part of the one layer, any part of the other layer, or any part of another layer between the one layer and the other layer. It may also refer to the boundary between any two of the one layer, the other layer, and the other layer.

[0019] [1. Air gap layer, laminate] As described above, the void layer of the present disclosure is a void layer to which a pulverized gel silicon compound is chemically bonded, the gel silicon compound being a compound formed by condensation or partial condensation of a silane compound, the silane compound including a mono- to tri-functional silane compound and a tetrafunctional silane compound, and the refractive index of the void layer is 1.30 or less. In another embodiment, the void layer of the present disclosure is a void layer to which a pulverized gel silicon compound is chemically bonded in the presence of an additive, the gel silicon compound being a compound formed by condensation or partial condensation of a silane compound, the additive including at least one of a crosslinking accelerator and its precursor, and a crosslinking auxiliary, the total content of the crosslinking accelerator and its precursor being 1.5 mol% or more, the total content of the crosslinking auxiliary being 2.0 mol% or more, and the refractive index of the void layer being 1.30 or less, relative to the total substance amount of the silane compound. The use of the porous layer of the present disclosure is not particularly limited, but it can be used, for example, in the laminate of the present disclosure described above.

[0020] Furthermore, as described above, the laminate of the present disclosure includes the void layer of the present disclosure and an adhesive layer. The adhesive layer is directly laminated on one or both sides of the void layer. In the present disclosure, the adhesive layer being "directly laminated" on the void layer may mean, for example, that the adhesive layer is in direct contact with the void layer, or that the adhesive layer is laminated on the void layer via the intermediate layer.

[0021] The cross-sectional view of Fig. 1(a) shows an example of the configuration of a laminate of the present disclosure. As shown in the figure, this laminate 10 has a tacky adhesive layer 12 directly laminated on one side of a porous layer 11. Here, the porous layer 11 is a porous layer to which a pulverized gel silicon compound is chemically bonded. The gel silicon compound is a compound obtained by condensing or partially condensing a silane compound. The silane compound includes a mono- to tri-functional silane compound and a tetra-functional silane compound, and the content ratio of the tetra-functional silane compound to the amount of the mono- to tri-functional silane compound is 1 to 25 mol%. The refractive index of the porous layer 11 is 1.30 or less.

[0022] 1(b) shows another example of the configuration of the laminate of the present disclosure. As shown in the figure, this laminate 10a has adhesive layers 12 directly laminated on both sides of a porous layer 11.

[0023] Furthermore, as described above, the laminate of the present disclosure may have 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. FIG. 2 shows an example of such a laminate of the present disclosure. As shown in FIG. 2(a), the laminate 10b has an adhesive layer 12 directly laminated on one side of the void layer 11. This laminate 10b is the same as the laminate 10 of FIG. 1(a), except that an intermediate layer 13 is present between the void layer 11 and the adhesive layer 12. The intermediate layer 13 is a layer formed by combining the void layer 11 and the adhesive layer 12. As shown in FIG. 2(b), the laminate 10c has an adhesive layer 12 directly laminated on both sides of the void layer 11. This laminate 10c is the same as the laminate 10a of FIG. 1(b), except that an intermediate layer 13 is present between the void layer 11 and each adhesive layer 12. The intermediate layer 13 is a layer formed by combining the void layer 11 and the adhesive layer 12, as in FIG. 2(a).

[0024] Furthermore, the laminate of the present disclosure may or may not include other components in addition to the void layer, the adhesive layer, and the intermediate layer. The other components are not particularly limited, and may be, for example, a substrate. The substrate is also not particularly limited, and may be, for example, a film (e.g., a resin film) or a glass plate, as described below. FIG. 3 shows an example of such a laminate of the present disclosure. The laminate 10d of FIG. 3(a) is the same as the laminate 10b of FIG. 2(a) except that, as shown, a substrate 14 is provided in direct contact with the surface of the void layer 11 opposite the adhesive layer 12, and on the surface of the adhesive layer 12 opposite the void layer 11. The laminate 10e of FIG. 3(b) is the same as the laminate 10c of FIG. 3(b) except that, as shown, a substrate 14 is provided in direct contact with the surface of each of the adhesive layers 12 on both sides opposite the void layer 11. In FIGS. 3(a) and 3(b), a substrate 14 is provided on both sides of the laminate. However, the present disclosure is not limited thereto, and for example, the substrate 14 may be provided on only one side. Also, in FIGS. 3(a) and 3(b), the substrate 14 is provided so as to be in direct contact with the void layer 11 or the adhesive layer 12. However, the present disclosure is not limited thereto, and for example, other components may be present between the substrate 14 and the void layer 11 or the adhesive layer 12. The other components are not particularly limited, and may be, for example, an optically functional layer. The optically functional layer is also not particularly limited, and may be, for example, an optically functional layer used in a general optical film, such as a microlens film, a prism film, a diffusion film, a polarizing reflective film, a polarizing film, a retardation film, or a high refractive index layer.

[0025] As described above, the void layer of the present disclosure is a void layer in which pulverized gel silicon compound particles are chemically bonded. By using the pulverized gel silicon compound, the three-dimensional structure of the gel silicon compound is destroyed, and a new three-dimensional structure different from that of the gel silicon compound is formed. In this way, the void layer becomes a layer in which a new pore structure (new void structure) that cannot be obtained in a layer formed from the gel silicon compound is formed, thereby forming a nanoscale void layer with high porosity. Furthermore, when the void layer is, for example, a gel silicon compound, the pulverized particles are chemically bonded together while adjusting the number of siloxane bond functional groups of the gel silicon compound. Here, the "gel silicon compound" refers to a polymeric porous material containing siloxane bonds, including, for example, a porous material containing silsesquioxane as a structural unit. Furthermore, after a new three-dimensional structure is formed as a precursor of the void layer, the void layer is chemically bonded (e.g., cross-linked) in a bonding step, so that, for example, when the void layer is a functional porous body, the void layer has a structure with voids but can maintain sufficient strength and flexibility. Therefore, according to the present disclosure, a void layer can be easily and simply applied to various objects.

[0026] In the void layer of the present disclosure, the form in which the pulverized materials are chemically bonded (form of chemical bond) is not particularly limited, and specific examples of the chemical bond include, for example, a covalent bond, an ionic bond, a metallic bond, etc. For example, the pulverized materials may be cross-linked (cross-linked) together by a covalent bond. Furthermore, the form of chemical bond (for example, the above-mentioned cross-linking) between the pulverized materials may be, for example, a form in which the pulverized materials are directly bonded together, or a form in which the pulverized materials are indirectly bonded together via other substances such as a cross-linking aid, a linker, or a spacer. The method for chemically bonding the pulverized materials is as described below in the method for manufacturing a void layer.

[0027] The crosslinked bond is, for example, a siloxane bond. Examples of siloxane bonds include the T2 bond, T3 bond, and T4 bond shown below. When the gel silicon compound has a siloxane bond, it may have, for example, any one type of bond, any two types of bonds, or all three types of bonds. The higher the ratio of T2 and T3 among the siloxane bonds, the more flexible the gel will be and the inherent properties of the gel can be expected, but the film strength will be weaker. On the other hand, if the ratio of T4 among the siloxane bonds is high, the film strength will be easily achieved, but the void size will be small and the flexibility will be weaker. For this reason, it is preferable to change the ratios of T2, T3, and T4 depending on the application, for example.

[0028] [ka]

[0029] When the porous layer of the present disclosure has the siloxane bond, the ratio of T2, T3, and T4, when expressed relatively with T2 set to "1," is, for example, T2:T3:T4=1:[1-100]:[0-50], 1:[1-80]:[1-40], or 1:[5-60]:[1-30].

[0030] In the porous layer of the present disclosure, the gel silicon compound is a compound obtained by condensation or partial condensation of a silane compound, as described above. The condensation can be, for example, dehydration condensation. The partially condensed state refers to a state in which, among the condensable functional groups (e.g., alkoxy groups) contained in the silane compound, some functional groups are condensed, while the remaining functional groups are not condensed and remain as condensable functional groups. In other words, some of the silane compounds are siloxane-bonded, while the remaining silane compounds are unbonded. The proportion of the unbonded silane compounds is, for example, less than 50%, 30% or less, or 15% or less.

[0031] As described above, the air gap layer of the present disclosure contains, as the silane compound, a mono- to tri-functional silane compound and a tetrafunctional silane compound. For example, the silane compound may contain at least one silane compound selected from the mono- to tri-functional silane compounds and may further contain a tetrafunctional silane compound. Examples of the mono- to tri-functional silane compound include mono- to tri-functional alkoxysilanes. Examples of the tetrafunctional silane compound include tetrafunctional alkoxysilanes. Examples of the monofunctional silane compound include trimethylmethoxysilane (TMMS), trimethylethoxysilane (TMES), trimethylpropoxysilane (TMPS), etc. Examples of the bifunctional silane compound include dimethyldimethoxysilane (DDMS), dimethyldiethoxysilane (DDES), dimethyldipropoxysilane (DDPS), etc. Examples of the trifunctional silane compounds include methyltrimethoxysilane (MTMS), methyltriethoxysilane (MTES), methyltripropoxysilane (MTPS), 3-acryloxypropyltriethoxysilane, 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.

[0032] In the porous layer of the present disclosure, the content ratio of the tetrafunctional silane compound relative to the amount of the mono- to trifunctional silane compound is, for example, 1 to 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, and the range is, for example, 2 to 20 mol%, 3 to 15 mol%, 3.5 to 15 mol%, or 3.5 to 10 mol%. Note that, from the viewpoint of ease of pulverization in the gel pulverization step, it is preferable that the content ratio is not too high. Furthermore, from the viewpoint of improving the strength of the low refractive index layer, it is preferable that the content ratio is not too low.

[0033] The void layer of the present disclosure is, for example, a void layer in which pulverized gel silicon compound particles are chemically bonded in the presence of an additive. The additive may contain, for example, at least one of a crosslinking reaction accelerator and a precursor thereof. The crosslinking reaction accelerator may be, for example, an acidic substance or a basic substance. The crosslinking reaction accelerator may also be, for example, a catalyst that accelerates chemical bonding (crosslinking) between the pulverized gel silicon compound particles. Furthermore, the precursor of the crosslinking reaction accelerator may also be, for example, a substance (crosslinking accelerator generator) that generates the crosslinking reaction accelerator by light or heat.

[0034] The chemical reaction that chemically bonds the gel silicon compounds together preferably utilizes the dehydration condensation reaction of residual silanol groups contained in silica sol molecules. Accelerating the reaction between the hydroxyl groups of the silanol groups with the crosslinking reaction accelerator enables continuous film formation by hardening the porous structure in a short time. Examples of the crosslinking reaction accelerator include photoactive catalysts and thermally active catalysts. The photoactive catalyst can chemically bond (e.g., crosslink) the gel silicon compounds together without heating, for example, in the bonding step described below. This reduces shrinkage of the pulverized material to be bonded during the bonding step, thereby maintaining a higher porosity. For example, a substance that generates a catalyst when exposed to light (a photocatalyst generator) may be used in addition to or instead of the photoactive catalyst, or a substance that generates a catalyst when exposed to heat (a thermal catalyst generator) may be used in addition to or instead of the thermally active catalyst. The photocatalyst generator is not particularly limited, but examples thereof include a photobase generator (a substance that generates a basic catalyst upon light irradiation) and a photoacid generator (a substance that generates an acidic catalyst upon light irradiation), and a photobase generator is preferred.Examples of the photobase generator include 9-anthrylmethyl N,N-diethylcarbamate (trade name WPBG-018), (E)-1-[3-(2-hydroxyphenyl)-2-propenoyl]piperidine (trade name WPBG-027), 1-(anthraquinon-2-yl)ethyl imidazolecarboxylate (trade name WPBG-140), 2-nitrophenylmethyl 4-methacryloyloxypiperidine-1-carboxylate (trade name WPBG-165), and 1,2-diisopropyl-3-[bis(dimethylamino)methylene]guanidium. Examples of suitable photoacid generators include 2-(3-benzoylphenyl)propionate (trade name WPBG-266), 1,2-dicyclohexyl-4,4,5,5-tetramethylbiguanidium n-butyltriphenylborate (trade name WPBG-300), and 2-(9-oxoxanthen-2-yl)propionic acid 1,5,7-triazabicyclo[4.4.0]dec-5-ene (Tokyo Chemical Industry Co., Ltd.), and a compound containing 4-piperidinemethanol (trade name HDPD-PB100, manufactured by Heraeus Chemical). All of the product names containing "WPBG" are trade names of Wako Pure Chemical Industries, Ltd. Examples of suitable photoacid generators include aromatic sulfonium salts (trade name SP-170, manufactured by ADEKA), triarylsulfonium salts (trade name CPI101A, manufactured by San-Apro), and aromatic iodonium salts (trade name Irgacure 250, manufactured by Ciba Japan). Furthermore, the crosslinking reaction accelerator that chemically bonds the pulverized gel silicon compound particles together is not limited to the photoactive catalyst and the photocatalyst generator, but may be, for example, a thermally active catalyst or a thermal catalyst generator such as urea. Examples of the crosslinking reaction accelerator that chemically bonds the pulverized gel silicon compound particles together include base catalysts such as potassium hydroxide, sodium hydroxide, and ammonium hydroxide, and acid catalysts such as hydrochloric acid, acetic acid, and oxalic acid. Among these, base catalysts are preferred.The crosslinking reaction accelerator and its precursor can be used by adding at least one of the crosslinking reaction accelerator and its precursor to a sol particle liquid (e.g., a suspension) containing the pulverized material (gel-like silicon compound) immediately before coating, or by using a mixed solution in which the crosslinking reaction accelerator and at least one of the precursors are mixed in a solvent. The mixed solution may be, for example, a coating solution in which the crosslinking reaction accelerator and at least one of the precursors are directly added to the sol particle liquid, a solution in which the crosslinking reaction accelerator and at least one of the precursors are dissolved in a solvent, or a dispersion in which the crosslinking reaction accelerator and at least one of the precursors are dispersed in a solvent. The solvent is not particularly limited, and examples include water and buffer solutions. The amount of the crosslinking reaction accelerator and its precursor added is not particularly limited, and is, for example, 0.01 to 20 wt %, 0.05 to 10 wt %, or 0.1 to 5 wt % relative to the weight of the gel-like silicon compound.

[0035] The lower limit of the total content of the crosslinking reaction accelerator and its precursor relative to the total amount of the mono- to trifunctional silane compound and the tetrafunctional silane compound 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.

[0036] In addition, in the void layer of the present disclosure, when the silane compound does not include the tetrafunctional silane compound, the lower limit of the total content ratio of the crosslinking reaction accelerator and its precursor relative to the total amount of substance 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.

[0037] Furthermore, the additive may contain, for example, a cross-linking auxiliary. The cross-linking auxiliary can be said to be a medium for indirectly bonding the pulverized gel silicon compound particles together through, for example, a chemical bond between the pulverized gel silicon compound particles and the cross-linking auxiliary. The cross-linking auxiliary penetrates between the pulverized particles, and the pulverized particles and the cross-linking auxiliary interact or bond with each other, making it possible to bond the pulverized particles that are somewhat distant from each other, and thus making it possible to efficiently increase strength.

[0038] The crosslinking aid is preferably a multi-crosslinked silane monomer, which specifically has, for example, 2 to 3 alkoxysilyl groups, the chain length between the alkoxysilyl groups may be 1 to 10 carbon atoms, and may also contain elements other than carbon. Examples of the crosslinking auxiliary 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, and tris-(3-triethoxysilylpropyl)isocyanurate. The amount of the crosslinking auxiliary added is not particularly limited, but is, for example, 0.01 to 20% by weight, 0.05 to 15% by weight, or 0.1 to 10% by weight relative to the weight of the gel silicon compound.

[0039] The lower limit of the total content of the crosslinking auxiliary relative to the total amount of the mono- to trifunctional silane compound and the tetrafunctional silane compound 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.

[0040] In addition, in the void layer of the present disclosure, when the silane compound does not include the tetrafunctional silane compound, the lower limit of the total content ratio of the crosslinking auxiliary relative to the total amount of substance 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.

[0041] The porous layer of the present disclosure has, for example, a pore structure. The pore size of the pores in the porous layer refers to the diameter of the major axis of the pores (pores) out of the diameter of the major axis and the diameter of the minor axis. The pore size is, for example, 5 nm to 200 nm. The pore size is, for example, 5 nm or more, 10 nm or more, or 20 nm or more, with the upper limit being, for example, 200 nm or less, 150 nm or less, 100 nm or less, 50 nm or less, 40 nm or less, or 30 nm or less, and the range is, for example, 5 nm to 200 nm, or 10 nm to 100 nm. The preferred pore size is determined depending on the application of the pore structure, and therefore, it is necessary to adjust the pore size to a desired size depending on, for example, the purpose. The pore size can be evaluated, for example, by the following method.

[0042] (Cross-sectional SEM observation of void layer) In the present disclosure, the morphology of the void layer can be observed and analyzed using a scanning electron microscope (SEM). Specifically, for example, the void layer is subjected to FIB processing (acceleration voltage: 30 kV) under cooling, and a cross-sectional sample obtained is subjected to FIB-SEM (manufactured by FEI: product name Helios NanoLab600, acceleration voltage: 1 kV) to obtain a cross-sectional electron image at a magnification of 100,000 times.

[0043] (Evaluation of void size) In the present disclosure, the pore size can be quantified by the BET test method. Specifically, 0.1 g of the sample (the porous layer) is placed in the capillary of a pore distribution / specific surface area analyzer (BELLSORP MINI, a product name of Microtrack Bell), and then dried under reduced pressure at room temperature for 24 hours to remove gas from the pore structure. Nitrogen gas is then adsorbed onto the sample, and a BET plot, a BJH plot, and an adsorption isotherm are plotted to determine the pore distribution. This allows the pore size to be evaluated.

[0044] The void layer of the present disclosure may have, for example, a pore structure (porous structure) as described above, and may be, for example, an open-cell structure in which the pore structure is continuous. The open-cell structure means, for example, that the pore structure in the void layer is connected three-dimensionally, and can also be described as a state in which the internal voids of the pore structure are continuous. When a porous body has an open-cell structure, it is possible to increase the porosity in the bulk, but an open-cell structure cannot be formed when closed-cell particles such as hollow silica are used. In contrast, the void layer has a three-dimensional dendritic structure, and therefore, the dendritic particles can easily form an open-cell structure in a coating film (a coating film of a sol containing the pulverized porous gel) by settling and depositing. Furthermore, it is more preferable that the void layer form a monolithic structure in which the open-cell structure has a plurality of pore distributions. The monolithic structure refers to, for example, a structure in which nano-sized fine voids exist and a hierarchical structure in which the nano-voids exist as an open-cell structure. When forming the monolithic structure, for example, it is possible to achieve both membrane strength with fine pores and high porosity with coarse open-cell pores. To form such a monolithic structure, for example, it is important to first control the pore distribution of the pore structure to be generated in the porous gel prior to pulverization into the pulverized material. Furthermore, for example, when pulverizing the porous gel, the particle size distribution of the pulverized material can be controlled to a desired size, thereby forming the monolithic structure.

[0045] In the air gap layer of the present disclosure, the haze indicating transparency is not particularly limited, and its lower limit is, for example, 0.1% or more, 0.2% or more, or 0.3% or more, and its upper limit is, for example, 10% or less, 5% or less, or 3% or less, and its range is, for example, 0.1 to 10%, 0.2 to 5%, or 0.3 to 3%.

[0046] The haze can be measured, for example, by the following method.

[0047] (Hayes's review) The porous layer (porous layer of the present disclosure) is cut to a size of 50 mm x 50 mm, and is set in a haze meter (HM-150 manufactured by Murakami Color Research Laboratory Co., Ltd.) to measure the haze. The haze value is calculated using the following formula. Haze (%) = [Diffuse transmittance (%) / Total light transmittance (%)] x 100 (%)

[0048] The refractive index of a medium is generally defined as the ratio of the propagation speed of the wavefront of light in a vacuum to the propagation speed within the medium. In this disclosure, the refractive index refers to the refractive index measured at a wavelength of 550 nm unless otherwise specified. The method for measuring the refractive index is not particularly limited, and can be measured, for example, by the following method.

[0049] As described above, the refractive index of the air-gap layer of the present disclosure is 1.30 or less. The upper limit of the refractive index of the air-gap layer 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, and 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 to less than 1.30, 1.05 or more to less than 1.30, 1.10 or more to less than 1.25, 1.15 or more to less than 1.25, or 1.19 or more to less than 1.25. The method for measuring the refractive index of the air-gap layer is not particularly limited, and can be measured, for example, by the following method.

[0050] The porosity of the porous layer has a lower limit of, for example, 30% by volume or more, or 50% by volume or more, and an upper limit of, for example, 90% by volume or less, 75% by volume or less, or 60% by volume or less, and the range is, for example, 30 to 90% by volume, 50 to 75% by volume, or 50 to 60% by volume.

[0051] (Evaluation of refractive index of gap layer) After forming a void layer (void layer of the present disclosure) on an acrylic film, the film was cut to a size of 50 mm x 50 mm and attached to the surface of a glass plate (thickness: 3 mm) using an adhesive layer. The center of the back surface of the glass plate (diameter: approximately 20 mm) was painted with black ink to prepare a sample that was non-reflective on the back surface of the glass plate. The sample was placed in an ellipsometer (JA Woollam Japan: VASE) and the refractive index was measured at a wavelength of 550 nm and an incident angle of 50 to 80 degrees, and the average value was taken as the refractive index.

[0052] After a heat and humidity durability test in which the film is maintained at a temperature of 85°C and a humidity of 85%RH for 500 hours, the residual void ratio of the porous layer is, for example, 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 measuring the refractive index of the porous layer is not particularly limited, and can be measured, for example, by the following method.

[0053] (Evaluation of void remaining rate in void layer) The laminate thus produced is placed in an oven at a temperature of 85°C and a humidity of 85%RH, and a heat and humidity durability test is carried out for 500 hours. After the heat and humidity durability test, the degree of filling of the voids in the porous layer is confirmed by SEM, and the remaining porosity can be calculated.

[0054] The thickness of the void layer of the present disclosure is not particularly limited, and the lower limit is, for example, 0.05 μm or more, or 0.1 μm or more, and the upper limit is, for example, 1000 μm or less, 100 μm or less, 10 μm or less, 5 μm or less, or 2 μm or less, and the range is, for example, 0.05 to 1000 μm, or 0.1 to 100 μm.

[0055] The form of the porous layer of the present disclosure is not particularly limited, and may be, for example, a film shape or a block shape.

[0056] The method for producing the void layer of the present disclosure is not particularly limited, but can be, for example, the method for producing a void layer described below or the method described in WO 2019 / 065999 and WO 2019 / 065803. The descriptions in these publications are incorporated herein by reference.

[0057] In the present disclosure, the adhesive layer is not particularly limited. In the present disclosure, the adhesive or pressure-sensitive adhesive forming the adhesive layer is not particularly limited, and for example, a general adhesive or pressure-sensitive adhesive can be used. Examples of the adhesive or pressure-sensitive adhesive include polymer adhesives such as acrylic, vinyl alcohol, silicone, polyester, polyurethane, and polyether adhesives, and rubber adhesives. Other examples include adhesives composed of water-soluble crosslinkers for vinyl alcohol polymers such as glutaraldehyde, melamine, and oxalic acid. These adhesives and pressure-sensitive adhesives may be used alone or in combination (e.g., mixed, laminated, etc.). The thickness of the adhesive layer is not particularly limited, and may be, for example, 0.1 to 100 μm, 5 to 50 μm, 10 to 30 μm, or 12 to 25 μm.

[0058] In the adhesive layer of the laminate of the present disclosure, the nanoindentation hardness is, for example, 0.5 MPa or more. The lower limit of the nanoindentation hardness may be, for example, 0.55 MPa or more, 0.6 MPa or more, or 0.65 MPa or more, and the upper limit may be, for example, 2.0 MPa or less, 1.5 MPa or less, 1.3 MPa or less, or 1.1 MPa or less. The method for measuring the nanoindentation hardness is not particularly limited, and it can be measured, for example, by the following method.

[0059] (Nanoindentation hardness evaluation) A measurement sample is cut into a size of about 1 cm square and fixed to a predetermined support, and the nanoindentation hardness of the adhesive layer in the laminate of the present disclosure is measured under the following conditions. The nanoindentation hardness can be measured by a nanoindentation method. ·Analyzer: Hysitron Inc., Triboindenter ·Indenter used: Conical (spherical: diameter 20μm) Measurement method: Single indentation measurement ·Measurement temperature: room temperature Indentation depth: 2000nm

[0060] The nanoindentation hardness is calculated from the maximum load (Pmax) and contact projected area (A) obtained by the measurement using the following formula. Nanoindentation hardness = Pmax / A

[0061] The nanoindentation hardness may be measured on either the surface of the adhesive layer or the cross section of the adhesive layer.

[0062] In the laminate of the present disclosure, the interlayer peel strength between the void layer and the adhesive layer, measured using a tensile tester at a tensile speed of 0.3 m / min, is, for example, 3 N / 25 mm or more. The lower limit of the peel strength may 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. Since the mechanical strength between layers of the laminate of the present disclosure improves as the peel strength increases, the upper limit of the peel strength is not particularly limited, but is, 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 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 method.

[0063] (Evaluation of interlayer peel strength) A resin film substrate having a void layer (void layer of the present disclosure) and a tacky adhesive layer (tacky adhesive layer of the laminate of the present disclosure) formed thereon was prepared, and an acrylic adhesive layer (20 μm thick) was bonded to the side of the resin film substrate opposite the void layer. The bonded sample was cut into 50 mm × 25 mm pieces to prepare adhesive tape pieces. Next, the tacky adhesive layer (10 μm thick) on the void layer side was bonded to a PET film (T100: manufactured by Mitsubishi Plastics Film Co., Ltd.) cut into a 25 mm × 100 mm strip, and the acrylic adhesive layer on the resin film substrate side was laminated to glass to secure it in place. The sample thus prepared was chucked in a tensile tester (manufactured by Shimadzu Corporation, product name: Autograph (registered trademark) AG-Xplus) with a chuck distance of 100 mm, and then subjected to a 180° peel test at a tensile speed of 0.3 m / min. A 50 mm peel test is carried out N=3 times, and the average test force is taken as the peel strength between the layers.

[0064] The refractive index of the void layer of the present disclosure measured in the state of the laminate is, for example, 1.30 or less. The upper limit of the refractive index of the void layer measured in the state of the laminate 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, and 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 to less than 1.30, 1.05 or more to less than 1.30, 1.10 or more to less than 1.25, 1.15 or more to less than 1.25, or 1.19 or more to less than 1.25. The method for measuring the refractive index of the void layer of the present disclosure measured in the state of the laminate is not particularly limited, and can be measured, for example, by the following method.

[0065] (Evaluation of refractive index of gap layer measured in laminate state) A prism of a prism coupler (manufactured by Metricon) is attached to the substrate side of a laminate (glass / adhesive layer / gap layer / acrylic substrate) in which an adhesive layer is provided on a gap layer, and the total reflection critical angle is measured using a laser. The refractive index can be calculated from the measured critical angle.

[0066] The laminate of the present disclosure may satisfy the following condition (1), for example, when the refractive index is X and the peel strength is Y. Fig. 4 shows a graph illustrating the relationship between the peel strength and the refractive index under condition (1). In Fig. 4, the horizontal axis represents the refractive index, and the vertical axis represents the peel strength (N / 25 mm). Condition (1): Y≧80X-93.8

[0067] Furthermore, the laminate of the present disclosure may satisfy the following condition (2), where the refractive index is X and the peel strength is Y. Fig. 4 shows a graph illustrating the relationship between the peel strength and the refractive index under condition (1). Condition (2): Y≧100X-117

[0068] When the condition (1) or the condition (2) is satisfied, for example, a laminate having a low refractive index and high peel strength (i.e., excellent mechanical strength) can be obtained. To satisfy the condition (1) and the condition (2), the types and content ratios of the tetrafunctional silane compound and the additives may be appropriately adjusted, without being particularly limited thereto.

[0069] In the present disclosure, the intermediate layer is not particularly limited, but for example, as described above, it is a layer formed by merging a part of the void layer with a part of the adhesive layer. The thickness of the intermediate layer is not particularly limited, but is, for example, 1 to 1500 nm, 5 to 1000 nm, 10 to 800 nm, or 20 to 500 nm.

[0070] The form of the laminate of the present disclosure is not particularly limited, but is usually in the form of a film.

[0071] The laminate of the present disclosure is, for example, a roll body. Furthermore, the laminate of the present disclosure may, for example, further include a resin film, as described above, and the void layer may be formed on the long resin film. In this case, another long film may be laminated on the laminate of the present disclosure, or another long resin film (for example, an interleaf paper, a release film, a surface protective film, etc.) may be laminated on the laminate of the present disclosure including the resin film and the void layer, and then wound into a roll body.

[0072] The method for producing the laminate of the present disclosure is not particularly limited, and the laminate can be produced, for example, by the production method of the present disclosure shown below. Furthermore, unless otherwise specified, the method for producing the optical laminate of the present disclosure that does not include a resin film can be performed in the same manner as the production method of the laminate of the present disclosure, except that no resin film is used.

[0073] [2. Method for manufacturing the air gap layer and method for manufacturing the laminate] The method for producing the void layer and the laminate of the present disclosure is not particularly limited, and can be, for example, the production method described below. However, the following description is an example and does not limit the present disclosure in any way.

[0074] A method for producing a laminate including a void layer according to the present disclosure includes, for example, a void layer forming step of forming the void layer, and an adhesive layer forming step of forming the adhesive layer on the void layer. The method for producing a laminate may further include an intermediate layer forming step of reacting the void layer with the adhesive layer to form the intermediate layer.

[0075] As described above, the void layer forming process (the void layer manufacturing method of the present disclosure) includes a gel silica synthesis process, a gel crushing process, and a bonding process. The void layer forming process (the void layer manufacturing method of the present disclosure) may or may not include other processes in addition to the gel silica synthesis process, the gel crushing process, and the bonding process. The other processes are not particularly limited, and examples thereof include a coating process and a drying process, which will be described later.

[0076] The gel silica synthesis step includes a step of synthesizing a gel silicon compound by condensing or partially condensing the silane compound. The gel silica synthesis step may include, for example, a step of gelling a massive porous body in a solvent to form a gel. In this case, the gel gelled in the gel silica synthesis step is used in, for example, the first grinding stage (e.g., the first grinding stage) of multiple grinding stages described below.

[0077] The method for producing the void layer includes, for example, an aging step of aging the gel in a solvent, and in this case, for example, the gel after the aging step is used in the first crushing step (e.g., the first crushing step) of the multiple crushing steps.

[0078] The gel-pulverizing step includes a step of pulverizing the gel silicon compound to obtain a pulverized product. The gel-pulverizing step may be performed in one step, but is preferably performed in multiple pulverizing steps. The number of pulverizing steps is not particularly limited, and may be, for example, two steps, or three or more steps.

[0079] The volume average particle diameter of the gel after the first pulverization step may be, for example, 0.5 to 100 μm, 1 to 100 μm, 1 to 50 μm, 2 to 20 μm, or 3 to 10 μm. The volume average particle diameter of the gel after the second pulverization step may be, for example, 10 to 1000 nm, 100 to 500 nm, or 200 to 300 nm. The volume average particle diameter indicates the particle size variation of the pulverized product in a liquid containing the gel (gel-containing liquid). The volume average particle diameter can be measured, for example, by a particle size distribution evaluation device such as a dynamic light scattering method or a laser diffraction method, or by an electron microscope such as a scanning electron microscope (SEM) or a transmission electron microscope (TEM).

[0080] In the method for producing a porous layer according to the present disclosure, for example, after the gel silica synthesis step, the solvent substitution step is performed to substitute the solvent with another solvent. In this case, for example, the gel in the other solvent is used in the first crushing step (e.g., the first crushing step) of the multiple crushing steps.

[0081] In at least one of the multiple grinding stages (e.g., at least one of the first grinding stage and the second grinding stage) of the method for manufacturing a porous layer of the present disclosure, the grinding of the porous body is controlled, for example, while measuring the shear viscosity of the liquid.

[0082] At least one of the multiple pulverization steps (for example, at least one of the first pulverization step and the second pulverization step) in the method for producing a porous layer according to the present disclosure is carried out by, for example, high-pressure media-less pulverization.

[0083] In the manufacturing method of the porous layer of the present disclosure, the gel pulverized material-containing liquid obtained by the process including the gel pulverization process may be simply referred to as "gel pulverized material-containing liquid" hereinafter.

[0084] The gel pulverized material-containing liquid can form a porous layer as a functional porous body by, for example, forming a coating film and chemically bonding the pulverized material in the coating film through a bonding process. The gel pulverized material-containing liquid can provide the porous layer to various objects. Therefore, the gel pulverized material-containing liquid and its manufacturing method are useful, for example, in manufacturing the porous layer.

[0085] The liquid containing the pulverized gel has, for example, extremely excellent uniformity, and therefore, when the porous layer is used for applications such as optical components, the appearance of the optical components can be improved.

[0086] The gel pulverized material-containing liquid may be, for example, a gel pulverized material-containing liquid that is applied (coated) onto a substrate (application process) and then dried (drying process) to obtain a layer having a high porosity (porous layer).

[0087] In the coating step, the coating method of the gel pulverized material-containing liquid is not particularly limited, and a general coating method can be used. Examples of the coating method include a slot die method, a reverse gravure coating method, a microgravure method (microgravure coating method), a dip method (dip coating method), a spin coating method, a brush coating method, a roll coating method, a flexographic printing method, a wire bar coating method, a spray coating method, an extrusion coating method, a curtain coating method, and a reverse coating method. Among these, from the viewpoints of productivity, smoothness of the coating film, etc., an extrusion coating method, a curtain coating method, a roll coating method, a microgravure coating method, etc. are preferred. The coating amount of the gel pulverized material-containing liquid is not particularly limited, and can be appropriately set, for example, so that the thickness of the void layer is appropriate. The thickness of the void layer is not particularly limited, and is, for example, as described above.

[0088] In the drying step, the pulverized gel-containing liquid is dried (i.e., the dispersion medium contained in the pulverized gel-containing liquid is removed) to form the dried coating film (a precursor of the porous layer). The drying temperature in the drying step is, for example, 50 to 250°C, 60 to 150°C, or 70 to 130°C, and the drying time is, for example, 0.1 to 30 minutes, 0.2 to 10 minutes, or 0.3 to 3 minutes. Regarding the drying temperature and time, lower and shorter drying temperatures are preferable, for example, in terms of continuous productivity and the development of a high porosity. If the conditions are too strict, for example, in the case of a resin film, the substrate may expand in the drying oven as the temperature approaches the glass transition temperature of the substrate, which may cause 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 upon exiting the drying oven, which may result in appearance defects such as scratches when rubbed against the roll in the next process.

[0089] The drying method may be, for example, natural drying, heat drying, or reduced pressure drying. The drying method is not particularly limited, and for example, a general heating means can be used. Examples of the heating means include a hot air blower, a heating roll, and a far-infrared heater. Among these, heat drying is preferably used when industrial continuous production is assumed.

[0090] The bonding step includes chemically bonding the pulverized material. The bonding step can be performed, for example, by irradiating or heating the coating film containing a catalyst or catalyst generator previously added to the gel pulverized material-containing liquid, or by spraying the catalyst onto the coating film and then irradiating or heating it, or by irradiating or heating it while spraying the catalyst or catalyst generator. The catalyst may be, for example, the crosslinking reaction accelerator or a strength improver that improves the strength of the void layer, and the crosslinking accelerator may also serve as the hardness improver.

[0091] The integrated light amount of the light irradiation is not particularly limited, but is, for example, 200 to 800 mJ / cm 2 in terms of @360 nm. 2 , 250-600mJ / cm 2 , or 300-400mJ / cm 2 From the viewpoint of preventing insufficient irradiation dose resulting in insufficient decomposition of the catalyst generator due to light absorption, the dose is set to 200 mJ / cm 2 In addition, from the viewpoint of preventing damage to the substrate under the air gap layer and the occurrence of thermal wrinkles, an integrated light intensity of 800 mJ / cm is recommended. 2 The following cumulative light intensity is recommended.

[0092] The heating temperature and heating time are not particularly limited, and the conditions for the heat treatment are not particularly limited. The heating temperature is, for example, 50 to 250°C, 60 to 150°C, or 70 to 130°C, and the heating time is, for example, 0.1 to 30 minutes, 0.2 to 10 minutes, or 0.3 to 3 minutes. Alternatively, the step of drying the applied pulverized gel-containing liquid as described above may also serve as a step of carrying out a chemical reaction in the presence of the catalyst. That is, in the step of drying the applied pulverized gel-containing liquid (e.g., a suspension), the pulverized gel particles may be chemically bonded together by a chemical reaction in the presence of the catalyst. In this case, the coated film may be further heated after the drying step to further strengthen the bond between the pulverized gel particles (microporous particles). Furthermore, it is believed that the chemical reaction in the presence of the catalyst may also occur in the step of preparing the microporous particle-containing liquid (e.g., a suspension) and the step of applying the microporous particle-containing liquid. However, this assumption does not limit the present invention in any way.

[0093] The adhesive layer forming step may include, for example, an adhesive coating liquid applying step of applying the adhesive coating liquid to a substrate and a heat drying step of heating and drying the substrate coated with the adhesive coating liquid. For example, the adhesive layer may be formed on the void layer by laminating the adhesive layer side of an adhesive tape or the like having the adhesive layer laminated on a substrate onto the void layer. In this case, the substrate such as the adhesive tape may be left attached as is or may be peeled off from the adhesive layer. In particular, peeling off the substrate to form a substrate-free (substrate-less) laminate can significantly reduce the thickness, thereby suppressing an increase in the thickness of a device or the like. In the present disclosure, the adhesive layer can be produced, for example, using the adhesive coating liquid as described above.

[0094] The adhesive layer forming step can be performed, for example, as follows. First, the adhesive coating liquid is produced by a mixing step of mixing all components of the adhesive coating liquid. The adhesive coating liquid may contain, for example, a (meth)acrylic polymer, and may or may not further contain a crosslinking agent (e.g., an isocyanate-based crosslinking agent or an epoxy-based crosslinking agent). The adhesive coating liquid may contain, for example, the (meth)acrylic polymer, a monomer having one or two reactive double bonds per molecule, a crosslinking agent, and an organic peroxide. In this case, when the adhesive coating liquid contains other components, the other components may also be mixed together. For example, the polymerization solvent used in producing the (meth)acrylic polymer may be mixed directly as a component of the adhesive coating liquid without removing it. Furthermore, the method for producing the adhesive coating liquid may or may not include other steps other than the mixing step, and may simply involve mixing all components of the adhesive coating liquid in the mixing step.

[0095] Next, the adhesive coating liquid is applied to a substrate (adhesive coating liquid application step). The substrate is not particularly limited and may be, for example, a substrate such as a film. Examples of suitable substrates include, but are not limited to, substrates made of thermoplastic resins, glass substrates, inorganic substrates such as silicon, plastics molded from thermosetting resins, semiconductor elements, and carbon fiber materials such as carbon nanotubes. Examples of the substrate include, but are not limited to, films and plates. Examples of thermoplastic resins include polyethylene terephthalate (PET), acrylic, cellulose acetate propionate (CAP), cycloolefin polymer (COP), triacetyl cellulose (TAC), polyethylene naphthalate (PEN), polyethylene (PE), and polypropylene (PP). In the adhesive coating liquid application step, the thickness of the adhesive coating liquid is not particularly limited and may be adjusted appropriately so that the adhesive layer after drying has a predetermined thickness. The thickness of the adhesive layer after drying is also not particularly limited and may be, for example, as described below.

[0096] Next, the substrate coated with the adhesive coating liquid is heated and dried (heat-drying step). In this heat-drying step, the heat-drying temperature is not particularly limited, but may be, for example, 50°C or higher, 80°C or higher, 100°C or higher, or 155°C or higher, and may be, for example, 200°C or lower, 180°C or lower, or 160°C or lower. The heat-drying time is not particularly limited, but may be, for example, 0.5 minutes or higher, 1 minute or higher, or 3 minutes or higher, and may be, for example, 60 minutes or lower, 30 minutes or lower, 20 minutes or lower, or 10 minutes or lower. In this heat-drying step, for example, a crosslinking reaction and graft polymerization occur between the (meth)acrylic polymer and the crosslinking agent. This reduces the amount of semi-high molecular weight polymer present in the adhesive coating liquid, as described above, making it difficult for the adhesive layer to penetrate into the recesses of the first optical sheet. In this manner, the adhesive layer used in the laminate of the present disclosure can be produced.

[0097] Next, as described above, the adhesive layer and the void layer are bonded together (lamination step). This method is not particularly limited, but for example, as described above, the adhesive layer may be formed on the void layer by bonding the adhesive layer side of an adhesive tape, etc., in which the adhesive layer of the present disclosure is laminated on a substrate, onto the void layer. In this manner, the laminate of the present disclosure can be produced.

[0098] The thickness of the adhesive layer is not particularly limited, and is, for example, 0.1 to 100 μm, 5 to 50 μm, 10 to 30 μm, or 12 to 25 μm.

[0099] In the method for producing a laminate according to the present disclosure, for example, a heating step of heating the adhesive layer and the void layer may be performed after the laminating step. Hereinafter, this heating step may be referred to as an "aging step." In the heating step (aging step), the heating temperature is not particularly limited, but may be, for example, 40°C or higher, 45°C or higher, or 50°C or higher, and may be, 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, but may be, for example, 1 minute or longer, 10 minutes or longer, 60 minutes or longer, or 1800 minutes or longer, and may be, for example, 3000 minutes or shorter, 2800 minutes or shorter, 2500 minutes or shorter, or 2000 minutes or shorter. In this aging step, for example, the void layer and the adhesive layer are united to form the intermediate layer. Then, for example, the intermediate layer acts as a stopper, and a decrease in porosity caused by filling the voids in the void layer with the adhesive can be suppressed. The fusion of the void layer and the adhesive layer may be such that the adhesive layer is embedded in the voids of the void layer and chemically bonded to it, or such that the adhesive layer is embedded in the voids of the void layer.

[0100] The adhesive layer can protect the void layer from physical damage (particularly scratches). The adhesive layer is preferably, but not particularly limited to, one that has excellent pressure resistance so that the void layer is not crushed even in a void layer-containing adhesive sheet that does not have a substrate (substrate-less).

[0101] The laminate of the present disclosure thus obtained may be further laminated with another film (layer) to form a laminate structure including the void layer (porous structure), as described above. In this case, in the laminate structure, each component may be laminated via, for example, the adhesive layer (adhesive or pressure-sensitive adhesive).

[0102] The lamination of the components may be carried out by continuous processing (so-called roll to roll, etc.) using a long film, for example, because this is more efficient. Alternatively, when the substrate is a molded product, element, etc., batch processing may be carried out and the components may be laminated.

[0103] [3. Optical Components] As described above, the optical member of the present disclosure includes the void layer of the present disclosure or the laminate of the present disclosure. The optical member of the present disclosure is characterized by including the void layer of the present disclosure or the laminate of the present disclosure, and other configurations are not limited in any way. The optical member of the present disclosure may further include other layers in addition to the void layer or the laminate, for example. The optical member of the present disclosure is, for example, in a roll form.

[0104] [4.Optical device] As described above, the optical device of the present disclosure includes the optical member of the present disclosure. The optical device of the present disclosure is not particularly limited, and may be, for example, an image display device or a lighting device. Examples of the image display device include a liquid crystal display, an organic electroluminescence (EL) display, and a micro LED (light emitting diode) display. Examples of the lighting device include an organic EL lighting device. [Example]

[0105] Next, examples of the present disclosure will be described, but the present disclosure is not limited to the following examples.

[0106] In the following Reference Examples, Examples, and Comparative Examples, the number of parts (relative amount used) of each substance is in parts by mass (parts by weight) unless otherwise specified. In the following Reference Examples, Examples, and Comparative Examples, a pressure-sensitive adhesive (pressure-sensitive adhesive composition) described below was used as the pressure-sensitive adhesive. In the following Reference Examples, Examples, and Comparative Examples, the term "pressure-sensitive adhesive layer" corresponds to the term "pressure-sensitive adhesive layer." That is, in the following Reference Examples, Examples, and Comparative Examples, the terms "pressure-sensitive adhesive layer" and "pressure-sensitive adhesive layer" have the same meaning unless otherwise specified.

[0107] In addition, in the following reference examples, examples, and comparative examples, the nanoindentation hardness, the refractive index of the void layer measured in the laminate state (refractive index (laminate)), and the refractive index when only the void layer is measured (refractive index (void layer)), peel strength, and void remaining rate were each measured using the methods described in the embodiments.

[0108] In the adhesive layers in the following Reference Examples, Examples, and Comparative Examples, it is presumed that the polymer (acrylic polymer) is crosslinked by the crosslinking agent when the applied adhesive is heated and dried, thereby forming a crosslinked structure, but the crosslinked structure has not been confirmed.

[0109] [Reference Example 1: Formation of adhesive layer (adhesive 1)] The adhesive layer of this Reference Example (Reference Example 1) was formed according to the following procedures (1) to (3).

[0110] (1) Preparation of acrylic polymer solution Into a four-neck flask equipped with a stirring blade, thermometer, nitrogen gas inlet tube, and condenser, 90.7 parts of butyl acrylate, 6 parts of N-acryloylmorpholine, 3 parts of acrylic acid, 0.3 parts of 2-hydroxybutyl acrylate, and 0.1 parts by weight of 2,2'-azobisisobutyronitrile as a polymerization initiator were placed, along with 100 g of ethyl acetate. Next, nitrogen gas was introduced into the four-neck flask while gently stirring the contents, replacing the atmosphere with nitrogen. The liquid temperature in the four-neck flask was then maintained at around 55°C, and a polymerization reaction was carried out for 8 hours to prepare an acrylic polymer solution.

[0111] (2) Preparation of acrylic adhesive composition An acrylic adhesive composition (acrylic adhesive solution) was prepared by blending 0.2 parts of an isocyanate crosslinking agent (trade name "Coronate L" manufactured by Nippon Polyurethane Industry Co., Ltd., an adduct of trimethylolpropane and tolylene diisocyanate), 0.3 parts of benzoyl peroxide (trade name "Niper BMT" manufactured by Nippon Oil & Fats Corporation), and 0.1 parts of γ-glycidoxypropylmethoxysilane (trade name "KBM-403" manufactured by Shin-Etsu Chemical Co., Ltd.) per 100 parts of the solids content of the acrylic polymer solution obtained in (1) above.

[0112] (3) Formation of adhesive layer The acrylic adhesive composition obtained in (2) above was applied to one side of a silicone-treated polyethylene terephthalate (PET) film (manufactured by Mitsubishi Chemical Polyester Film Corporation, thickness: 38 μm) so that the adhesive layer would have a thickness of 10 μm after drying, and the coating was dried at 150°C for 3 minutes to form adhesive layer (adhesive layer) 1.

[0113] [Reference Example 2: Formation of adhesive layer (adhesive 2)] The adhesive layer of this Reference Example (Reference Example 2) was formed according to the following procedures (1) to (3).

[0114] (1) Preparation of (meth)acrylic polymer (A1) solution A four-neck flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser was charged with a monomer mixture containing 79.5 parts of butyl acrylate, 15 parts of N-acryloylmorpholine, 5 parts of acrylic acid, and 0.5 parts of 4-hydroxybutyl acrylate. Furthermore, 0.1 parts of 2,2'-azobisisobutyronitrile as a polymerization initiator and 70 parts of ethyl acetate were charged to 100 parts of the monomer mixture. Nitrogen gas was introduced with gentle stirring to replace the atmosphere. The temperature in the flask was maintained at around 55°C, and a polymerization reaction was carried out for 2 hours to prepare a solution of a (meth)acrylic polymer (A1) with a weight average molecular weight (Mw) of 3,000,000 and an Mw / Mn ratio of 2.5.

[0115] (2) Preparation of (meth)acrylic adhesive composition 0.2 parts of an isocyanate crosslinking agent (trade name "Coronate L" manufactured by Nippon Polyurethane Industry Co., Ltd., an adduct of trimethylolpropane and tolylene diisocyanate) and 0.2 parts of an epoxy crosslinking agent 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane (trade name "Tetrad C" manufactured by Mitsubishi Gas Chemical Company, Inc.) were blended with 100 parts of the solid content of the obtained solution of the (meth)acrylic polymer (A1) to prepare a solution of an acrylic pressure-sensitive adhesive composition.

[0116] (3) Formation of adhesive layer Next, the solution of the acrylic pressure-sensitive adhesive composition was applied to one side of a polyethylene terephthalate film (separator film: MRF38, manufactured by Mitsubishi Chemical Polyester Film Corporation) that had been treated with a silicone-based release agent, so that the thickness of the pressure-sensitive adhesive layer after drying would be 10 μm, and the coating was dried at 155°C for 1 minute to form a pressure-sensitive adhesive layer (adhesive layer) called Pressure-sensitive Adhesive 2 on the surface of the separator film.

[0117] [Reference Example 3: Formation of adhesive layer (adhesive 3)] The adhesive layer of this Reference Example (Reference Example 3) was formed according to the following procedures (1) to (3).

[0118] (1) Preparation of acrylic polymer solution Into a four-neck flask equipped with a stirring blade, thermometer, nitrogen gas inlet tube, and condenser, 99 parts of butyl acrylate, 1 part of 4-hydroxybutyl acrylate, and 0.1 parts of 2,2'-azobisisobutyronitrile as a polymerization initiator were placed, along with 100 parts of ethyl acetate. Next, nitrogen gas was introduced into the four-neck flask while gently stirring the contents, to replace the atmosphere with nitrogen. Thereafter, the liquid temperature in the four-neck flask was maintained at around 55°C, and a polymerization reaction was carried out for 8 hours to prepare an acrylic polymer solution.

[0119] (2) Preparation of acrylic adhesive composition A solution of an acrylic pressure-sensitive adhesive composition was prepared by blending 0.1 parts of an isocyanate crosslinking agent (Takenate D110N, product name, manufactured by Mitsui Takeda Chemicals, Inc., trimethylolpropane xylylene diisocyanate), 0.1 parts of benzoyl peroxide (Niper BMT, product name, manufactured by Nippon Oil & Fats Corporation), and 0.2 parts of γ-glycidoxypropyl methoxysilane (KBM-403, product name, manufactured by Shin-Etsu Chemical Co., Ltd.) with 100 parts of the solid content of the acrylic polymer solution obtained in (1) above.

[0120] (3) Formation of adhesive layer The solution of the acrylic pressure-sensitive adhesive composition obtained in (2) above was applied to one side of a polyethylene terephthalate film (separator film: manufactured by Mitsubishi Chemical Polyester Film Corporation, product name "MRF38") treated with a silicone-based release agent, and dried at 150°C for 3 minutes to form a pressure-sensitive adhesive layer (adhesive layer) 3 having a thickness of 20 μm on the surface of the separator film.

[0121] [Examples 1 to 8 and Comparative Examples 1 to 3: Production of Laminates Including Void Layers] Laminates including a void layer in Examples 1 to 8 and Comparative Examples 1 to 3 were produced by the following method.

[0122] Example 1 (1) Gelation of silicon compounds (gel silica synthesis process) Mixture A was prepared by dissolving 1.90 g of methyltrimethoxysilane (MTMS), a precursor of a silicon compound, and 0.1 g of tetraethoxysilane (TEOS) in 4.4 g of dimethyl sulfoxide (DMSO). 1.0 g of 0.01 mol / L oxalic acid solution was added to this mixture A and stirred at room temperature for 30 minutes to hydrolyze MTMS, producing mixture B containing tris(hydroxy)methylsilane and tetra(hydroxy)silane. 0.38 g of 28 wt% aqueous ammonia and 0.2 g of pure water were added to 5.5 g of DMSO, and then the mixture B was further added and stirred at room temperature for 15 minutes to gel the tris(hydroxy)methylsilane and tetra(hydroxy)silane, resulting in mixture C containing a gel-like silicon compound.

[0123] (2) Aging treatment The mixed solution C containing the gel-like silicon compound prepared as above was incubated as is at 40° C. for 20 hours for aging treatment.

[0124] (3) Crushing process (gel crushing process) Next, the gel-like silicon compound aged as described above was crushed into granules of several mm to several cm in size using a spatula. Next, 40 g of isopropyl alcohol (IPA) was added to mixed solution C, and after light stirring, the mixture was left to stand at room temperature for 6 hours, and the solvent and catalyst in the gel were decanted. The same decantation process was repeated three times to replace the solvent, yielding mixed solution D. The gel-like silicon compound in mixed solution D was then crushed (high-pressure media-less crushing). The crushing process (high-pressure media-less crushing) was carried out using a homogenizer (manufactured by SMT Corporation, product name "UH-50"), with 1.85 g of the gel-like compound in mixed solution D and 1.15 g of IPA weighed into a 5 cc screw bottle, and crushed for 2 minutes at 50 W and 20 kHz.

[0125] This grinding process pulverized the gel-like silicon compound in the mixed solution D, turning the mixed solution D into a ground sol solution E. The volume average particle size, which indicates the particle size variation of the ground material contained in the sol solution E, was measured using a dynamic light scattering Nanotrac particle size analyzer (manufactured by Nikkiso Co., Ltd., UPA-EX150 model) and found to be 0.50 to 0.70 μm. Furthermore, to 0.75 g of the sol solution E, 0.124 g of a 1.5 wt % MEK (methyl ethyl ketone) solution of a photobase generator (Wako Pure Chemical Industries, Ltd., product name: WPBG266), which is a precursor of the crosslinking reaction accelerator, and 0.036 g of a 5% MEK solution of a crosslinking auxiliary (bis(trimethoxysilyl)hexane) were added in the following ratios to obtain a coating solution for forming a low refractive index layer.

[0126] The coating solution for forming a low refractive index layer was applied to an acrylic substrate and dried to form a voided layer with a thickness of approximately 850 nm (void ratio: 59% by volume). The coating was performed using a wire bar, and the drying temperature and drying time were 100°C and 2 minutes, respectively. Next, UV irradiation (300 mJ) was performed from the voided layer surface to bond the pulverized gel compound particles together (bonding process). The bonding between the pulverized gel compound particles in the bonding process is presumed to include at least one of crosslinking (covalent bonding) in which the pulverized particles are directly bonded without a crosslinking auxiliary agent, and crosslinking (covalent bonding) via the crosslinking auxiliary agent. A 10 μm-thick adhesive 1 was then attached to the voided layer surface and aged at 50°C for 30 hours to produce the voided layer of this example. The laminate of this example was also produced using the produced voided layer.

[0127] Example 2 The air gap layer of this example was produced by the same procedure as in Example 1, except that the amounts of photobase generator and crosslinking aid added in Example 1 were changed to 0.186 g of a 1.5 wt % MEK (methyl ethyl ketone) solution of photobase generator (Wako Pure Chemical Industries, Ltd., product name: WPBG266) and 0.054 g of a 5% MEK solution of crosslinking aid (1,6-bis(trimethoxysilyl)hexane) per 0.75 g of sol solution E. The air gap layer of this example was also produced using the produced air gap layer.

[0128] Example 3 The air gap layer of this example was produced by the same procedure as in Example 1, except that the amount of tetraethoxysilane (TEOS) added in Example 1 was changed to 0.2 g. The air gap layer thus produced was used to produce the laminate of this example.

[0129] Example 4 The air gap layer of this example was produced by the same procedure as in Example 2, except that the amount of tetraethoxysilane (TEOS) added in Example 1 was changed to 0.2 g. The produced air gap layer was used to produce the laminate of this example.

[0130] Example 5 The air gap layer of this example was produced in the same manner as in Example 1, except that adhesive 2 was used instead of adhesive 1 used in Example 1. The produced air gap layer was then used to produce the laminate of this example.

[0131] Example 6 The air gap layer of this example was produced by the same procedure as in Example 1, except that the amount of tetraethoxysilane (TEOS) added in Example 1 was changed to 0.3 g. The air gap layer thus produced was used to produce the laminate of this example.

[0132] Example 7 The air gap layer of this example was produced by the same procedure as in Example 1, except that the amount of tetraethoxysilane (TEOS) added in Example 1 was changed to 0.4 g. The air gap layer thus produced was used to produce the laminate of this example.

[0133] Example 8 The air gap layer of this example was produced by the same procedure as in Example 1, except that the amount of tetraethoxysilane (TEOS) added in Example 1 was changed to 0.2 g, and the amounts of the photobase generator and bis-crosslinking accelerator added were changed to 0.062 g of a 1.5 wt % MEK (methyl ethyl ketone) solution of the photobase generator (Wako Pure Chemical Industries, Ltd., product name: WPBG266) and 0.018 g of a 5% MEK solution of the bis-crosslinking accelerator ((trimethoxysilyl)hexane), relative to 0.75 g of sol solution E. The air gap layer of this example was also produced using the produced air gap layer.

[0134] (Comparative Example 1) The air gap layer of this comparative example was produced in the same manner as in Example 9, except that tetraethoxysilane (TEOS) was not added. The produced air gap layer was used to produce a laminate of this comparative example.

[0135] (Comparative Example 2) The void layer of this comparative example was produced in the same manner as in Comparative Example 1, except that adhesive 2 was used instead of adhesive 1 used in Comparative Example 1. The produced void layer was then used to produce the laminate of this example.

[0136] (Comparative Example 3) The void layer of this comparative example was produced in the same manner as in Comparative Example 1, except that adhesive 3 was used instead of adhesive 1 used in Comparative Example 1. The produced void layer was then used to produce a laminate of this comparative example.

[0137] [Table 1]

[0138] As shown in Table 1, the laminates including the porous layer of the examples had good interlayer peel strengths of 3 N / 25 mm or more, whereas the laminates of the comparative examples all had interlayer peel strengths of less than 3 N / 25 mm.

[0139] Figure 4 shows a graph illustrating the relationship between peel strength and refractive index for Examples and Comparative Examples in which the nanoindentation hardness of a laminate is 0.5 MPa or more. In Figure 4, the formula "Y = 136.4x - 159.92" is a linear function obtained by averaging the two data points of Examples 1 and 2, in which a tetrafunctional silane compound was blended at 3.5 mol% relative to the trifunctional silane compound, and only the amounts of the crosslinking assistant and crosslinking accelerator-generating substance were varied. The formula "Y = 141.37x - 165.06" is a linear function obtained by averaging the three data points of Examples 3, 4, and 8, in which a tetrafunctional silane compound was blended at 6.9 mol% relative to the trifunctional silane compound, and only the amounts of the crosslinking assistant and crosslinking accelerator-generating substance were varied.

[0140] As shown in Figure 4, in all Examples, the peel strength between the void layer and the adhesive layer was 3N / 25 mm or more. Furthermore, the void layers of all Examples satisfied the condition (1) (Y ≥ 80X - 93.8) described in the embodiment. Furthermore, it was found that the void layers of the Examples, which contain a tetrafunctional silane compound as a silane compound, exhibited higher peel strength than void layers having the same refractive index but not containing a tetrafunctional silane compound. In other words, the condition (2) (Y ≥ 100X - 117) described in the embodiment was satisfied. Furthermore, by increasing the content of the crosslinking auxiliary and the crosslinking reaction accelerator (precursor of the crosslinking reaction accelerator), the peel strength was further improved.

[0141] The present disclosure can be described, for example, as in the following supplementary notes: However, the supplementary notes below are examples, and the present disclosure is not limited to these forms.

[0142] (Appendix 1) A void layer, the porous layer is a porous layer in which pulverized gel silicon compound particles are chemically bonded, The gel silicon compound is a compound obtained by condensing or partially condensing a silane compound, The silane compound includes a monofunctional to trifunctional silane compound and a tetrafunctional silane compound, The refractive index of the air gap layer is 1.30 or less. void layer. (Appendix 2) the content ratio of the tetrafunctional silane compound relative to the amount of the mono- to trifunctional silane compound is 1 to 25 mol %; The void layer described in Appendix 1. (Appendix 3) the void layer is a void layer in which the pulverized gel silicon compound is chemically bonded in the presence of an additive, The additive contains at least one of a crosslinking reaction accelerator and a precursor thereof, the precursor is a substance that generates the crosslinking reaction accelerator by exposure to light or heat; Attachment 1 or 2, the void layer. (Appendix 4) 4. The porous layer according to claim 3, wherein the crosslinking reaction accelerator is an acidic substance or a basic substance. (Appendix 5) 5. The porous layer according to claim 3, wherein the total content of the crosslinking reaction accelerator and its precursor is 1 mol % or more relative to the total amount of the mono- to tri-functional silane compound and the tetrafunctional silane compound. (Appendix 6) the void layer is a void layer in which the pulverized gel silicon compound is chemically bonded in the presence of an additive, The additives include a crosslinking aid. 6. The void layer according to any one of appendices 1 to 5. (Appendix 7) 7. The porous layer according to claim 6, wherein the total content of the crosslinking auxiliary is 1 mol % or more with respect to the total amount of the mono- to tri-functional silane compound and the tetrafunctional silane compound. (Appendix 8) A void layer, the void layer is a void layer in which pulverized gel silicon compound particles are chemically bonded in the presence of an additive; The gel silicon compound is a compound obtained by condensing or partially condensing a silane compound, The additives include at least one of a crosslinking reaction accelerator and a precursor thereof, and a crosslinking auxiliary; With respect to the total amount of the silane compounds, the total content of the crosslinking reaction accelerator and its precursor is 1.5 mol% or more, The total content of the crosslinking auxiliary agent is 2.0 mol% or more, The refractive index of the air gap layer is 1.30 or less. void layer. (Appendix 9) The method includes a gel silica synthesis step, a gel crushing step, and a bonding step, the gel silica synthesis step includes a step of synthesizing a gel silicon compound by condensing or partially condensing a silane compound, The silane compound includes a monofunctional to trifunctional silane compound and a tetrafunctional silane compound, The gel-crushing step includes a step of crushing the gel silicon compound to obtain a crushed product, The bonding step includes a step of chemically bonding the pulverized material. A method for manufacturing a void layer. (Appendix 10) A method for manufacturing a gap layer, comprising: The method includes a gel silica synthesis step, a gel crushing step, and a bonding step, the gel silica synthesis step includes a step of synthesizing a gel silicon compound by condensing or partially condensing a silane compound, The gel-crushing step includes a step of crushing the gel silicon compound to obtain a crushed product, The bonding step includes a step of chemically bonding the pulverized material in the presence of an additive, The additives include at least one of a crosslinking reaction accelerator and a precursor thereof, and a crosslinking auxiliary. A method for manufacturing a void layer. (Appendix 11) A porous layer according to any one of Supplementary Notes 1 to 8 and an adhesive layer, A laminate in which the adhesive layer is directly laminated on one or both sides of the porous layer. (Appendix 12) An optical member comprising the air gap layer according to any one of appendices 1 to 8. (Appendix 13) An optical member comprising the laminate according to claim 11. (Appendix 14) 13. An optical device comprising the optical element according to claim 12. (Appendix 15) 15. The optical device according to claim 14, which is an image display device or an illumination device. (Appendix 16) 14. An optical device comprising the optical element according to claim 13. (Appendix 17) 17. The optical device according to claim 16, which is an image display device or an illumination device. [Industrial Applicability]

[0143] As described above, the present disclosure can provide a void layer having a low refractive index and excellent mechanical strength, a method for manufacturing a void layer, a laminate, an optical member, and an optical device. The applications of the present disclosure are not particularly limited. For example, the optical device of the present disclosure is not particularly limited, and examples thereof include image display devices and lighting devices. Examples of the image display devices include liquid crystal displays, organic EL displays, and micro LED displays. Examples of the lighting devices include organic EL lighting. Furthermore, the applications of the laminate of the present disclosure are not limited to the optical members and optical devices of the present disclosure, and are arbitrary, and can be used for a wide range of applications. [Explanation of symbols]

[0144] 10, 10a, 10b, 10c, 10d, 10e laminate 11 Porous layer 12 Adhesive layer 13 Middle class 14 Base material

Claims

1. a dispersion medium and microporous particles; the microporous particles are pulverized gel silicon compounds, The gel silicon compound is a compound obtained by condensing or partially condensing a silane compound, The silane compound includes a monofunctional to trifunctional silane compound and a tetrafunctional silane compound. Liquid containing microporous particles.

2. the content ratio of the tetrafunctional silane compound to the amount of the mono- to trifunctional silane compound is 1 to 25 mol %; The microporous particle-containing liquid according to claim 1 .

3. the microporous particle-containing liquid contains at least one of a crosslinking reaction accelerator and a precursor thereof, the precursor is a substance that generates the crosslinking reaction accelerator by exposure to light or heat; The microporous particle-containing liquid according to claim 1 .

4. the crosslinking reaction accelerator is an acidic substance or a basic substance; The microporous particle-containing liquid according to claim 3.

5. the total content ratio of the crosslinking reaction accelerator and its precursor is 1 mol % or more with respect to the total substance amount of the mono- to tri-functional silane compound and the tetrafunctional silane compound; The microporous particle-containing liquid according to claim 3.

6. The microporous particle-containing liquid contains a crosslinking aid. The microporous particle-containing liquid according to claim 1 .

7. a total content ratio of the crosslinking auxiliary to the total amount of the mono- to tri-functional silane compound and the tetrafunctional silane compound is 1 mol % or more; The microporous particle-containing liquid according to claim 6.

8. A microporous particle-containing liquid in which microporous particles are dispersed in a dispersion medium, the microporous particles are pulverized gel silicon compounds, The gel silicon compound is a compound obtained by condensing or partially condensing a silane compound, the microporous particle-containing liquid contains at least one of a crosslinking reaction accelerator and a precursor thereof, and a crosslinking assistant; With respect to the total amount of the silane compounds, the total content of the crosslinking reaction accelerator and its precursor is 1.5 mol% or more, The total content of the crosslinking auxiliary agent is 2.0 mol% or more. Liquid containing microporous particles.

9. A coating liquid comprising the microporous particle-containing liquid according to claim 1 or 8.

10. The coating liquid according to claim 9, which is a coating liquid for forming a low refractive index layer.

11. The method includes a gel silica synthesis step and a gel crushing step, the gel silica synthesis step includes a step of synthesizing a gel silicon compound by condensing or partially condensing a silane compound, The silane compound includes a monofunctional to trifunctional silane compound and a tetrafunctional silane compound, The gel crushing step includes a step of crushing the gel silicon compound to obtain a gel crushed material-containing liquid. A method for producing a liquid containing microporous particles.

12. The method includes a gel silica synthesis step, a gel crushing step, and an addition step, the gel silica synthesis step includes a step of synthesizing a gel silicon compound by condensing or partially condensing a silane compound, The gel crushing step includes a step of crushing the gel silicon compound to obtain a gel crushed material-containing liquid, The adding step includes adding at least one of a crosslinking reaction accelerator and a precursor thereof, and a crosslinking auxiliary to the gel pulverized material-containing liquid. A method for producing a liquid containing microporous particles.

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