Optical member, manufacturing method thereof, and light distribution element

Abstract

An optical member (100) that functions as an optical coupling layer has a first layer (10) having a porous structure, and a second layer (20) contacting a first main surface of the first layer. The second layer (20) includes a resin composition, and has a transmittance of 5% to 85% with regard to a first light that is within the wavelength range of greater than 800 nm and less than or equal to 2000 nm. The first layer (10) includes a first region (12) having the porous structure, and a second region (14) in which pores of the porous structure are filled with a resin composition.

Description

[Technical Field]

[0001] The present invention relates to an optical member, a manufacturing method thereof, and a light distribution element. [Background technology]

[0002] A known method for extracting light from a light guide layer is to provide a textured surface on the light guide layer, but it is difficult to accurately form a precise textured surface on the light guide layer.

[0003] Patent Document 1 discloses a method for selectively extracting guided-mode light from a light-guiding layer by forming a variable-refractive-index light-extraction layer on the light-guiding layer, in which two regions with different refractive indices are geometrically arranged. The two regions with different refractive indices in the variable-refractive-index light-extraction layer are formed by selectively printing nanovoided polymer materials with different refractive indices.

[0004] Patent Document 2 discloses a method for forming a light extraction layer having two regions with different refractive indexes that is simpler than the method described in Patent Document 1. According to Patent Document 2, for example, a pressure-sensitive adhesive layer is formed on a porous layer, and the pressure-sensitive adhesive layer is irradiated with laser light in a predetermined pattern, and the voids in the porous layer are filled with the molten pressure-sensitive adhesive, thereby forming a light extraction layer in which low-refractive-index regions with remaining voids and high-refractive-index regions with the voids filled with the pressure-sensitive adhesive are arranged in a predetermined pattern.

[0005] The entire disclosure of Patent Document 2 is incorporated herein by reference. In this specification, the light extraction layer in Patent Document 2 may be referred to as an "optical coupling layer." Furthermore, "extracting light" in Patent Document 2 may be referred to as "taking out light" or "coupling light." [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent Publication No. 2015-534100 (International Publication No. 2014 / 031726) [Patent Document 2] International Publication No. 2019 / 182100 Summary of the Invention [Problem to be solved by the invention]

[0007] According to the investigations of the present inventors, with the method of utilizing laser light irradiation described in Patent Document 2, for example, it was sometimes difficult to efficiently form a relatively high-definition pattern.

[0008] Therefore, an object of the present invention is to provide a method for forming an optical coupling layer (light extraction layer) having a relatively high-resolution pattern more efficiently than conventional methods, and further to provide an optical element having such an optical coupling layer, a method for manufacturing the same, and a light distribution element having such an optical element. [Means for solving the problem]

[0009] According to an embodiment of the present invention, the following solutions are provided:

[0010] [Item 1] a first layer having a porous structure; a second layer in contact with the first main surface of the first layer; and the second layer contains a resin composition and has a transmittance of 5% or more and 85% or less for a first light having a wavelength range of more than 800 nm and not more than 2000 nm, The optical member includes a first region having the porous structure, and a second region in which voids in the porous structure are filled with the resin composition.

[0011] [Item 2] Item 2. The optical element according to item 1, wherein the second layer has adhesive properties.

[0012] [Item 3] The optical member according to item 2, further comprising a release sheet disposed on the side of the second layer opposite to the first layer.

[0013] [Item 4] The optical member according to any one of items 1 to 3, wherein the resin composition contains a coloring material that absorbs the first light.

[0014] [Item 5] The optical member according to any one of items 1 to 4, wherein the second layer has a transmittance of 70% or less with respect to the first light.

[0015] [Item 6] The optical member according to any one of items 1 to 5, wherein when the refractive index of the first region is n1, the refractive index of the second region is n2, and the refractive index of the second layer is n3, n1 < n2 and n1 < n3.

[0016] [Item 7] The optical member according to item 6, wherein n1 is 1.30 or less and n2 is 1.43 or more.

[0017] [Item 8] The optical member according to any one of items 1 to 7, wherein the resin composition contains a photocurable resin.

[0018] [Item 9] The optical member according to any one of items 1 to 8, wherein the first layer contains a silica porous body.

[0019] [Item 10] An optical member according to any one of items 1 to 9, and a light guide layer disposed on the side of the first layer to form a light distribution element.

[0020] [Item 11] The light distribution element according to item 10, further comprising a direction conversion layer disposed on the side of the optical member opposite to the light guide layer.

[0021] [Item 12] a first layer having a porous structure and a second layer in contact with a first main surface of the first layer; the second layer comprises a resin composition, a method for producing an optical member, wherein the first layer includes a first region having the porous structure and a second region in which voids in the porous structure are filled with the resin composition, Step A of preparing a laminate including a porous layer having a porous structure and an infrared absorbing resin composition layer that contains a resin composition and has a transmittance of 5% or more and 85% or less for first light in a wavelength range of more than 800 nm and not more than 2000 nm; a step B of selectively irradiating only a predetermined region of the infrared absorbing resin composition layer of the laminate with the first light, thereby filling the resin composition contained in the infrared absorbing resin composition layer of the predetermined region into voids of the porous structure of the porous layer; The manufacturing method includes the steps of:

[0022] [Item 13] Item 13. The manufacturing method according to item 12, wherein the infrared absorbing resin composition layer contains the resin composition and a colorant that absorbs the first light.

[0023] [Item 14] Item 14. The method according to Item 12 or 13, wherein the step A includes a step A1 of forming the infrared absorbing resin composition layer on the porous layer.

[0024] [Item 15] Item 15. The manufacturing method according to Item 14, wherein the step A1 includes a step of forming the infrared absorbing resin composition layer using a material obtained by mixing the resin composition and the colorant.

[0025] [Item 16] Item 15. The manufacturing method according to item 14, wherein the step A1 includes forming a resin composition layer formed from the resin composition, and forming a colorant layer containing the colorant on the resin composition layer.

[0026] [Item 17] the resin composition contains a photocurable resin, 17. The method according to any one of items 12 to 16, further comprising the step of curing the photocurable resin after step B. [Effects of the Invention]

[0027] According to an embodiment of the present invention, a method for forming a light extraction layer having a relatively high-resolution pattern more efficiently than conventional methods is provided, and further, an optical element having such a light extraction layer and a manufacturing method thereof, and a light distribution element having such an optical element are provided. [Brief explanation of the drawings]

[0028] [Figure 1] 1 is a schematic cross-sectional view of an optical member 100 according to an embodiment of the present invention. [Figure 2] FIG. 1 is a schematic cross-sectional view of a light distributing element 200A having an optical member 100a according to an embodiment of the present invention. [Figure 3] FIG. 2 is a schematic cross-sectional view of a light distributing element 200B having an optical member 100b according to an embodiment of the present invention. [Figure 4A] 1 is a schematic plan view showing an example of the arrangement of first regions 12a and second regions 14a in a first layer 10a of an optical member according to an embodiment of the present invention. [Figure 4B] 1 is a schematic plan view showing an example of the arrangement of first regions 12b and second regions 14b in a first layer 10b of an optical member according to an embodiment of the present invention. FIG. [Figure 5A] 1 is a schematic cross-sectional view showing one step in the manufacturing process of the optical member 100. FIG. [Figure 5B] 1 is a schematic cross-sectional view showing one step in the manufacturing process of the optical member 100. FIG. [Figure 5C] 1 is a schematic cross-sectional view showing one step in the manufacturing process of the optical member 100. FIG. [Figure 5D] 1 is a schematic cross-sectional view showing one step in the manufacturing process of the optical member 100. FIG. [Figure 6] FIG. 2 is a cross-sectional view schematically illustrating the configuration of a light distribution element sample. [Figure 7A] 2 is a schematic cross-sectional view of a shaped film 70. FIG. [Figure 7B] 3 is a schematic cross-sectional view showing a recess 74 of a shaped film 70. FIG. [Figure 8] FIG. 10 is a diagram showing a cross-sectional SEM image of the optical member obtained in Example 3. [Figure 9] FIG. 2 is a schematic cross-sectional view of a light distributing element 200C according to an embodiment of the present invention. [Figure 10] FIG. 10 is a schematic cross-sectional view of a light distribution element 200D. DETAILED DESCRIPTION OF THE INVENTION

[0029] Hereinafter, an optical member, a method for manufacturing an optical member, and a light distributing element including an optical member according to an embodiment of the present invention will be described with reference to the drawings. The embodiment of the present invention is not limited to the following examples.

[0030] Optical elements according to embodiments of the present invention can extract light propagating through a light guide layer from the principal surface of the light guide layer or guide it to an optical element arranged in contact with the principal surface. Guiding light propagating through a light guide layer to an optical element arranged in contact with the principal surface of the light guide layer is referred to as optical coupling, and a layer that performs this function is called an optical coupling layer. For example, optical elements according to embodiments of the present invention are suitable for use as the optical coupling layer of a light guide element described in, for example, Japanese Patent Application No. 2020-127530 (filed July 28, 2020) by the present applicant. As described in the above patent application, the optical coupling layer can be provided between the light guide layer and the light redirecting layer. The light redirecting layer has, for example, multiple internal spaces that form interfaces that direct light toward the principal surface of the light redirecting layer by total internal reflection. A light redirecting layer having such internal spaces can be, for example, the light distribution structure disclosed in International Publication No. 2019 / 087118. The light redirecting layer can also be a known prism sheet. The entire disclosures of Japanese Patent Application No. 2020-127530 and International Publication No. 2019 / 087118 are incorporated herein by reference.

[0031] FIG. 1 shows a schematic cross-sectional view of an optical member 100 according to an embodiment of the present invention. The optical member 100 includes a first layer 10 having a porous structure and a second layer 20 in contact with a first major surface of the first layer 10. The second layer 20 contains a resin composition and has a transmittance of 5% or more and 85% or less with respect to first light within a wavelength range exceeding 800 nm and not exceeding 2000 nm. The first layer 10 includes a first region 12 having a porous structure and a second region 14 in which the voids of the porous structure are filled with the resin composition.

[0032] The optical member according to an embodiment of the present invention may have a base material layer 30 that supports the first layer 10 having a porous structure, such as the optical member 100 illustrated herein. Further, when the second layer 20 has adhesiveness, it may have a release sheet (separator) 40 disposed on the side of the second layer 20 opposite to the first layer 10. The base material layer 30 and / or the release sheet 40 may be omitted.

[0033] The second layer 20 contains a resin composition and has a transmittance of 5% or more and 85% or less with respect to first light within a wavelength range exceeding 800 nm and not exceeding 2000 nm. That is, since the second layer 20 absorbs the first light (near infrared light), it can be efficiently heated by irradiating the first light. As a result, the resin composition in the region of the second layer 20 irradiated with the first light is melted, and the resin composition is selectively filled into the voids of the porous structure of the first layer 10. The first region 12 having a porous structure has a refractive index smaller than that of the second region 14 in which the voids of the porous structure are filled with the resin composition.

[0034] When the refractive index of the first region 12 is n1, the refractive index of the second region 14 is n2, and the refractive index of the second layer 20 is n3, then n1 < n2 and n1 < n3. At this time, for example, the relationship n2 < n3 is satisfied. n1 is, for example, 1.30 or less, n2 is, for example, 1.43 or more, and n3 is, for example, 1.45 or more.

[0035] The first layer 10 may be formed, for example, of a porous silica material. The porosity of the porous silica material is greater than 0% and less than 100%. To obtain a low refractive index, the porosity is preferably 40% or more, more preferably 50% or more, and even more preferably 55% or more. There is no particular upper limit to the porosity, but from the viewpoint of strength, it is preferably 95% or less, and more preferably 85% or less.

[0036] The refractive index of silica (the matrix portion of the porous silica body) is preferably, for example, 1.41 or more and 1.43 or less. The second layer 20 can be formed from various resin compositions. The refractive index of typical resins is generally 1.45 or more and 1.70 or less. The resin composition may contain a photocurable resin. The refractive index n2 of the second region 14 can be controlled by adjusting the porosity of the porous structure contained in the first layer 10 and the refractive index n3 of the resin composition contained in the second layer 20. |n2-n3| is preferably 0.1 or less. Total internal reflection at the interface between the second layer 20 and the second region 14 of the first layer 10 can be suppressed.

[0037] By arranging the first regions 12 and the second regions 14 in a predetermined pattern, the first layer 10 can be obtained, for example, as an optical coupling layer. The optical coupling layer is disposed between two optical layers, for example, between a light guide layer and a light redirecting layer, and guides a portion of the light propagating through the light guide layer to the light redirecting layer. The light redirecting layer has, for example, an interface (or surface) that imparts a layer-normal component to the propagating light. The light redirecting layer can be, for example, a prism sheet.

[0038] The second layer 20 absorbs the first light and can be efficiently heated by irradiating it with the first light. Therefore, a relatively high-resolution pattern can be formed more efficiently than with conventional methods. The transmittance of the second layer 20 to the first light is preferably 70% or less, and more preferably 65% ​​or less.

[0039] Generally, organic substances absorb infrared light, so that infrared spectroscopy is used to identify them. The wavelength range (fingerprint region) of infrared light used to identify organic substances is 400 cm in wavenumber.-1 ~4000cm -1 Infrared rays have wavelengths of 2.5 μm to 25 μm, and general organic materials hardly absorb infrared rays with wavelengths of 2 μm (20,000 nm) or less. Organic materials that absorb infrared rays are sometimes called infrared absorbing dyes.

[0040] The resin composition of the second layer 20 includes, for example, a resin composition that hardly absorbs the first light and a colorant that absorbs the first light. The colorant may include a pigment (or dye). Note that a pigment (or dye) refers to a coloring material that is soluble in a solvent (e.g., water or alcohol), while a pigment refers to a coloring material that is insoluble or poorly soluble in a solvent. Note that an atomic group that absorbs the first light may be chemically introduced (i.e., by chemical bonding) into the resin itself contained in the resin composition.

[0041] The first light preferably has a wavelength within the range of 900 nm to 1500 nm, and more preferably 1200 nm or less. The first light is preferably laser light, and is preferably emitted from a solid-state laser. An LED can also be used. The half-width of the first light is, for example, 100 nm or less. The amount of light irradiation required to form the second region can be determined by adjusting the intensity and irradiation time of the irradiated light. Furthermore, a focusing optical system such as a lens may be used as necessary.

[0042] Next, the configurations and functions of light distributing elements 200A and 200B according to embodiments of the present invention will be described with reference to FIGS.

[0043] The light distribution element 200A shown in FIG. 2 has an optical member 100a and a light guide layer 50 arranged on the first layer 10 side of the optical member 100a. A base layer 60 is arranged on the side of the optical member 100a opposite the light guide layer 50. The base layer 60 can be replaced with, for example, a direction conversion layer (e.g., a prism sheet). For simplicity of explanation, an example will be described in which a transparent base layer 60 having a flat main surface is provided in contact with the second layer 20. The base layer 60 can be made of the same material as the light guide layer 50.

[0044] Here, the first layer 10, the second layer 20, the light guide layer 50, and the base layer 60 of the optical member 100a have main surfaces parallel to the XY plane. Light emitted from the light source LS toward the light-receiving end surface (not shown) of the light guide layer 50 propagates in the Y direction within the light guide layer 50 (guided light L P A part of the light incident on the light guide layer 50 is optically coupled (extracted) to the base layer 60 by the optical member 100a and is emitted in the Z direction (emitted light L E ) Of course, the propagation direction of light varies (distribution) from the Y direction, and the emission direction of light also varies (distribution) from the Z direction. The X direction is perpendicular to the Y and Z directions.

[0045] Light L propagating in the light guide layer 50 P is totally internally reflected at the interface between the light guide layer 50 and the first region 12 of the first layer 10 and at the interface between the light guide layer 50 and air, and propagates in the Y direction. Of the light that enters the light guide layer 50, light that enters the interface between the light guide layer 50 and the second region 14 of the first layer 10 passes through the second layer 20 and the base layer 60 without being totally internally reflected, and is emitted from the light distribution element 200A.

[0046] The arrangement of the optical members is not limited to the example shown in FIG. 2. As in the light distribution element 200B shown in FIG. 3, the second layer 20 of the optical member 100b may be arranged on the light guide layer 50 side, and the first layer 10 of the optical member 100b may be arranged on the base layer 60 side. In this case, the light L propagating in the light guide layer 50 P is totally internally reflected at the interface between the second layer 20 and the first region 12 of the first layer 10, and light incident on the interface between the second layer 20 and the second region 14 of the first layer passes through the second region 14 of the first layer 10 and the base layer 60 without being totally internally reflected, and is emitted from the light distribution element 200B.

[0047] By adjusting the arrangement of the first region 12 and the second region 14 of the first layer 10 in the layer plane (parallel to the XY plane), it is possible to control the light distribution (emission intensity distribution, emission angle distribution, etc.) of the light extracted from the light-guiding layer 50 (optically coupled with the base layer 60) by the optical element 100a.

[0048] The arrangement of the first region 12 and the second region 14 in the first layer 10 is set appropriately according to the required light distribution.

[0049] In the first layer 10a shown in Fig. 4A, a plurality of rectangular second regions 14a elongated in the X direction are arranged at intervals along the Y direction within a first region 12a. The intervals between the plurality of rectangular second regions 14a become narrower along the Y direction. That is, the density of the second regions 14a is arranged to increase along the Y direction. This is to allow light that enters the light guide layer from a light source (not shown) located on the left side of Fig. 4A and propagates in the Y direction to be emitted uniformly in the Z direction regardless of the distance from the light source.

[0050] In the first layer 10b shown in Fig. 4B, a plurality of circular second regions 14b are discretely arranged within the first region 12b. Corresponding to the rectangular second regions 14a elongated in the X direction in Fig. 4A, a plurality of second regions 14b are arranged in a line in the X direction. The density of the second regions 14b is also increased along the Y direction.

[0051] In this way, the arrangement of the first regions 12 and the second regions 14 in the first layer 10 can be modified in various ways. The shape of each second region 14 is not limited to a rectangle or a circle, and can be various shapes. Also, a rectangular second region 14a and a circular second region 14b can be used in combination.

[0052] The shape, dimensions, in-plane density of the first layer 10, and occupancy rate of the second region 14 within the first layer 10 can be appropriately changed depending on the purpose and application of the optical member. For example, when good visibility, such as transparency, is required, the major axis of each second region 14 is preferably 100 μm or less, and more preferably 70 μm or less. For example, as shown in FIG. 4B, in the case of a circular second region 14, the diameter of the circle is preferably 100 μm or less. In applications where devices equipped with optical members are viewed from a relatively close distance, such as mobile displays and small signage, the second region 14 can be prevented from being visible.

[0053] Next, examples of components that can be suitably used in the light distributing element according to the embodiment of the present invention will be described.

[0054] (light guiding layer) A wide variety of known light guide layers (light guides) can be used for the light guide layer. The light guide layer can typically be made of a film or plate of resin (preferably transparent resin). The resin may be a thermoplastic resin or a photocurable resin. Examples of thermoplastic resins include (meth)acrylic resins such as polymethyl methacrylate (PMMA) and polyacrylonitrile, polyester resins such as polycarbonate (PC) resin and PET, cellulose resins such as triacetyl cellulose (TAC), cyclic polyolefin resins, and polystyrene resins. Examples of photocurable resins that can be used include epoxy acrylate resins and urethane acrylate resins. These resins may be used alone or in combination of two or more.

[0055] The thickness of the light guide layer can be, for example, 100 μm or more and 100 mm or less, and is preferably 50 mm or less, more preferably 30 mm or less, and even more preferably 10 mm or less.

[0056] Refractive index n of the light guide layer GPis, for example, a value in the range of -0.1 to +0.1 relative to the refractive index n3 of the second layer, and the lower limit is preferably 1.43 or more, more preferably 1.47 or more. On the other hand, the upper limit of the refractive index of the light guide layer is 1.7.

[0057] Refractive index n of the light guide layer GP When the first region of the first layer is disposed so as to be in direct contact with the light guide layer (see FIG. 2), the refractive index n1 of the first region and the refractive index n3 of the second layer are set so that light is totally internally reflected at the interface between the light guide layer and the first region of the first layer. When the first region of the first layer is disposed on the light guide layer via a second layer (see FIG. 3), the refractive index n1 of the first region and the refractive index n3 of the second layer are set so that light is totally internally reflected at the interface between the second layer and the first region, and the refractive index n of the light guide layer is set so that total internal reflection is unlikely to occur at the interface between the light guide layer and the second region. GP and the refractive index of the second region n2 is set. GP It is preferable that −n2| is 0.1 or less.

[0058] Although a conventional light guide layer having an uneven surface can be used as the light guide layer, a light guide layer having a substantially flat surface, such as the light guide layer 50 shown in Figures 2 and 3, can be preferably used. The optical element 100 functioning as an optical coupling layer according to the embodiment of the present invention has a substantially flat main surface, and therefore can be easily laminated with the light guide layer 50 having a substantially flat surface, as well as with other optical elements having substantially flat surfaces. A substantially flat surface means that the uneven surface does not refract or diffusely reflect light.

[0059] (Porous layer, first region of first layer) The first layer has a porous structure. The first layer can be formed from a porous material. Porous materials suitable for use as the first layer include silica particles, silica particles with micropores, approximately spherical particles such as hollow silica nanoparticles, fibrous particles such as cellulose nanofibers, alumina nanofibers, and silica nanofibers, and flat particles such as nanoclay composed of bentonite. In one embodiment, the porous layer is a porous body formed by direct chemical bonding of particles (e.g., microporous particles). Furthermore, at least a portion of the particles constituting the porous layer may be bonded to each other via a small amount (e.g., less than the mass of the particles) of a binder component. The porosity and refractive index of the porous layer can be adjusted by the particle size, particle size distribution, etc. of the particles constituting the porous layer.

[0060] Methods for obtaining a porous layer include, for example, the method for forming a low refractive index layer described in WO 2019 / 146628, as well as methods described in JP 2010-189212 A, JP 2008-040171 A, JP 2006-011175 A, WO 2004 / 113966 A, JP 2017-054111 A, JP 2018-123233 A, and JP 2018-123299 A and references thereto. All of the disclosures of these publications are incorporated herein by reference.

[0061] A porous silica material can be suitably used as the porous layer. Porous silica materials can be produced, for example, by the following methods. Examples include a method of hydrolyzing and polycondensing at least one of silicon compounds, hydrolyzable silanes and / or silsesquioxanes, and their partial hydrolysates and dehydration condensates; a method using porous particles and / or hollow fine particles; a method of producing an aerogel layer by utilizing the springback phenomenon; and a method of using a pulverized gel obtained by pulverizing a gel-like silicon compound obtained by a sol-gel method and chemically bonding the resulting pulverized microporous particles together with a catalyst or the like. However, the porous layer is not limited to porous silica materials, and the production method is not limited to the exemplified methods, and any production method may be used. Silsesquioxane can be (RSiO1.5 , R is a hydrocarbon group) as a basic structural unit. Although it is technically different from silica, which has SiO2 as a basic structural unit, it shares with silica the network structure cross-linked by siloxane bonds. Therefore, in this document, porous materials containing silsesquioxane as a basic structural unit are also referred to as porous silica materials or silica-based porous materials.

[0062] The porous silica material can be composed of microporous particles of a gel-like silicon compound bonded to one another. Examples of the microporous particles of the gel-like silicon compound include pulverized gel-like silicon compounds. The porous silica material can be formed, for example, by applying a coating liquid containing the pulverized gel-like silicon compound to a substrate. The pulverized gel-like silicon compound can be chemically bonded (e.g., siloxane bonded) by, for example, the action of a catalyst, light irradiation, heating, etc.

[0063] The lower limit of the thickness of the porous layer (first layer) may be, for example, greater than the wavelength of the light used. Specifically, the lower limit is, for example, 0.3 μm or more. There is no particular limitation on the upper limit of the thickness of the first layer, but it is, for example, 5 μm or less, and more preferably 3 μm or less. If the thickness of the first layer is within the above range, the surface irregularities will not be so large as to affect lamination, making it easy to form a composite or laminate with other components.

[0064] The refractive index of the porous layer, i.e., the refractive index n1 of the first region of the first layer, is preferably 1.30 or less. Total internal reflection is likely to occur at the interface in contact with the first region, i.e., the critical angle can be reduced. The refractive index n1 of the first region is more preferably 1.25 or less, even more preferably 1.18 or less, and particularly preferably 1.15 or less. There is no particular lower limit for n1, but from the viewpoint of mechanical strength, it is preferably 1.05 or more.

[0065] The lower limit of the porosity of the porous layer, i.e., the porosity of the first region of the first layer, is, for example, 40% or more, preferably 50% or more, more preferably 55% or more, and even more preferably 70% or more. The upper limit of the porosity of the porous layer is, for example, 90% or less, more preferably 85% or less. By ensuring that the porosity is within the above range, the refractive index of the first region can be set to an appropriate range. The porosity can be calculated, for example, from the refractive index measured with an ellipsometer using the Lorentz-Lorenz formula.

[0066] The film density of the porous layer, i.e., the film density of the first region of the first layer, is, for example, 1 g / cm 3 or more, preferably 10 g / cm 3 More preferably, it is 15 g / cm 3 On the other hand, the film density is, for example, 50 g / cm 3 or less, preferably 40 g / cm 3 or less, more preferably 30 g / cm 3 More preferably, it is 2.1 g / cm or less. 3 The film density range is, for example, 5 g / cm 3 More than 50g / cm 3 or less, preferably 10 g / cm 3 More than 40g / cm 3 or less, more preferably 15 g / cm 3 More than 30g / cm 3 Alternatively, the range may be, for example, 1 g / cm 3 More than 2.1g / cm 3 The film density can be measured by known methods.

[0067] (Second region of the first layer) The second region of the first layer is formed by filling the voids in the porous layer with the resin composition contained in the second layer. The refractive index n2 of the second region satisfies the relationship n1 < n2 and n1 < n3, where n1 is the refractive index of the first region and n3 is the refractive index of the second layer. By satisfying this relationship for n2, it is possible to suppress the scattering of light due to reflection and refraction at the interface between the first region and the second region in the plane direction of the first layer. The lower limit value of n2 is, for example, greater than 1.30, preferably 1.35 or more, and more preferably 1.40 or more.

[0068] The first region and the second region of the first layer are formed from a common porous layer. That is, the first layer has a continuous porous structure over the entire first region and second region. Let n be the refractive index of the material constituting the matrix portion of the porous layer (the portion other than the voids in the porous layer). M Then, the refractive index of the porous layer, that is, the refractive index n1 of the first region, is determined by n M and the porosity and the refractive index of air, and the refractive index n2 of the second region is determined by n M and the porosity and the refractive index n3 of the second layer (resin composition) and the filling rate of the resin composition with respect to the voids. For example, as described above, when a silica porous body is used as the porous layer, n M is, for example, 1.41 or more and 1.43 or less, and when the refractive index of the resin is greater than n M (for example, 1.45 or more and 1.70 or less), the relationship n1 < n2 < n3 can be obtained.

[0069] Since the second region of the first layer is formed by filling the voids with the resin composition, the adhesion to other optical elements (for example, a light guiding layer) of the first layer can be improved. Also, the mechanical strength of the first layer can be improved. In particular, when the resin composition has adhesiveness (including tackiness), the effect of improving the adhesion and mechanical strength is large.

[0070] (The second layer) The lower limit of the refractive index n3 of the second layer is, for example, 1.45 or more, and preferably 1.47 or more. On the other hand, the upper limit of the refractive index n3 of the second layer is not particularly limited, but is, for example, 1.70 or less. From an optical standpoint, it is preferable that the refractive index (n3) of the second layer has a value that is the same as or close to the refractive index of an optical element (e.g., a light guide layer, a base layer, or a direction changing layer) that is arranged in contact with the second layer (or via an adhesive layer). The difference between the refractive index of the second layer and the refractive index of the optical element adjacent to the second layer is preferably 0.1 or less, and more preferably 0.05 or less.

[0071] The thickness of the second layer is not particularly limited as long as it has enough strength to support the first layer, but the lower limit is, for example, 1 μm or more, preferably 5 μm or more, and more preferably 10 μm or more. The upper limit of the thickness of the second layer is, for example, 200 μm or less, and preferably 150 μm or less.

[0072] The second layer is formed using a resin composition. The resin composition has a transmittance of 5% or more and 85% or less for first light in a wavelength range of more than 800 nm and not more than 2000 nm. The resin composition includes, for example, a resin composition that hardly absorbs the first light and a colorant that absorbs the first light.

[0073] The resin composition preferably has adhesive properties, and particularly preferably has pressure-sensitive adhesive properties (i.e., stickiness). A pressure-sensitive adhesive can be suitably used as the resin composition forming the second layer. The pressure-sensitive adhesive preferably has a storage modulus that does not penetrate into the voids of the porous structure of the first region of the first layer under conditions of room temperature and normal pressure or under heating conditions such as the aging step described below, and is preferably melted or softened by irradiation with the first light, penetrates into the voids of the porous structure, and fills the voids with the resin composition. From these viewpoints, the lower limit of the storage modulus of the pressure-sensitive adhesive is, for example, 1.0 × 10 5 (Pa) or more is preferable, and 1.2×10 5 The upper limit of the storage modulus of the pressure-sensitive adhesive is, for example, 1.0 × 10 6The molecular weight (mass average molecular weight) of the resin composition is not particularly limited as long as the resin composition can penetrate into the voids of the porous structure, but the resin composition contains, for example, a component having a molecular weight of 100,000 or less, 70,000 or less, 50,000 or less, 30,000 or less, or 10,000 or less.

[0074] As the pressure-sensitive adhesive, a wide range of commonly available pressure-sensitive adhesives can be used as long as they have the above-mentioned properties. For example, acrylic, urethane, ester, and silicone pressure-sensitive adhesives can be used. Rubber-based (e.g., polybutadiene, nitrile, and chloroprene) pressure-sensitive adhesives can also be used.

[0075] For example, acrylic pressure-sensitive adhesives typically contain a (meth)acrylic polymer as the main component (base polymer). The (meth)acrylic polymer may be contained in the pressure-sensitive adhesive in a proportion of, for example, 50% by mass or more, preferably 70% by mass or more, and more preferably 90% by mass or more of the solid content of the pressure-sensitive adhesive. The (meth)acrylic polymer contains alkyl (meth)acrylate as the main component as a monomer unit. Here, (meth)acrylate refers to acrylate and / or methacrylate. Examples of the alkyl group of the alkyl (meth)acrylate include linear or branched alkyl groups having 1 to 18 carbon atoms. The average number of carbon atoms in the alkyl group is preferably 3 to 9. Examples of monomers constituting the (meth)acrylic polymer include alkyl (meth)acrylates as well as comonomers such as carboxyl group-containing monomers, hydroxyl group-containing monomers, amide group-containing monomers, aromatic ring-containing (meth)acrylates, and heterocycle-containing (meth)acrylates. The comonomer is preferably a hydroxyl group-containing monomer and / or a heterocycle-containing (meth)acrylate, more preferably N-acryloylmorpholine. The acrylic pressure-sensitive adhesive may preferably contain a silane coupling agent and / or a crosslinking agent. Examples of the silane coupling agent include an epoxy group-containing silane coupling agent. Examples of the crosslinking agent include an isocyanate-based crosslinking agent and a peroxide-based crosslinking agent. Details of such pressure-sensitive adhesives are described, for example, in Japanese Patent No. 4140736, the entire disclosure of which is incorporated herein by reference.

[0076] A method for manufacturing an optical member according to an embodiment of the present invention includes the steps of: preparing a laminate including a porous layer having a porous structure and an infrared-absorbing resin composition layer containing a resin composition and having a transmittance of 5% to 85% for first light in a wavelength range of more than 800 nm and less than 2000 nm; and selectively irradiating a predetermined region of the infrared-absorbing resin composition layer of the laminate with the first light, thereby filling voids in the porous structure of the porous layer with the resin composition contained in the infrared-absorbing resin composition layer in the predetermined region. The step of preparing a laminate may be a step of manufacturing a laminate, or a step of preparing a manufactured laminate. The step of preparing a laminate may include, for example, forming an infrared-absorbing resin composition layer on the porous layer. An example of a method for manufacturing an optical member 100 will be described with reference to FIGS. 5A, 5B, 5C, and 5D. FIGS. 5A, 5B, 5C, and 5D are each schematic cross-sectional views illustrating a step in the manufacturing process of the optical member 100.

[0077] First, as shown in FIG. 5A, a porous layer 10 having a porous structure that will become the first layer 10 is formed on a substrate layer 30. Here, for simplicity, the porous layer and the first layer are denoted by the same reference numeral 10. The substrate layer 30 is, for example, a polymer film. On the substrate layer 30, a porous layer 10 made of, for example, porous silica is formed. The porous layer 10 is formed by the known method described above.

[0078] Meanwhile, as shown in FIG. 5B, an infrared-absorbing resin composition layer 20 that will become the second layer 20 is formed on a release sheet (separator) 40. For simplicity, the infrared-absorbing resin composition layer and the second layer are denoted by the same reference numeral 20. The infrared-absorbing resin composition layer 20 contains a resin composition and has a transmittance of 5% to 85% for first light in a wavelength range of more than 800 nm and not more than 2000 nm. By irradiating the infrared-absorbing resin composition layer 20, which has the property of effectively absorbing the first light, with the first light (FIG. 5D), the resin composition in the irradiated region can be selectively and efficiently heated. As a result, a first layer 10 is formed having second regions arranged in a relatively high-resolution pattern.

[0079] The infrared-absorbing resin composition layer 20 can be formed, for example, using a material obtained by mixing a resin composition with a colorant that absorbs the first light. The resin composition may barely absorb the first light. Alternatively, a resin composition layer made of a resin composition may be formed, and a colorant layer containing a colorant that absorbs the first light may be formed on the resin composition layer. In this case, the resin composition layer and the colorant layer on the resin composition layer constitute the infrared-absorbing resin composition layer. Separately forming the colorant layer may have the advantage of suppressing deterioration of the colorant. Radical initiators (e.g., AIBN, BPO, etc.) and acrylic acid remaining in the adhesive may deteriorate the colorant, reducing its ability to absorb near-infrared light (the first light). Some or all of the colorant layer deposited on the resin composition layer may penetrate and diffuse into the resin composition, becoming integrated with the resin composition.

[0080] The colorant may be either a dye (pigment) or a pigment, although dyes are preferred because they can be uniformly distributed in a resin composition (such as a pressure-sensitive adhesive).

[0081] The coloring material is preferably one that absorbs light in the wavelength range of 900 nm to 1500 nm. Specific examples include phthalocyanine-based, azo-based, phenylenediamine-based, anthraquinone-based, naphthoquinone-based, and cyanine-based materials. These may be used alone or in combination of two or more. Among these, phenylenediamine-based materials, which have high transmittance to visible light, are preferred. As the phenylenediamine-based dye, for example, a diimonium compound can be suitably used.

[0082] Next, as shown in FIG. 5C , an infrared-absorbing resin composition layer 20 is disposed on the porous layer 10. Here, an example is shown in which an optical member 100 is manufactured using a film-like substrate layer 30 and a release sheet 40. The method of disposing the infrared-absorbing resin composition layer 20 on the porous layer 10 by stacking films on top of each other is excellent in terms of mass productivity. Of course, the process of forming the infrared-absorbing resin composition layer 20 on the porous layer 10 is not limited to this, and various methods (such as various coating methods and printing methods) known as methods for forming a resin layer (for example, a pressure-sensitive adhesive layer) can be used.

[0083] Next, the first light LB is selectively irradiated only onto the infrared absorbing resin composition layer 20 in a predetermined region on the region that is to become the second region 14 of the porous layer 10, thereby filling the resin composition contained in the infrared absorbing resin composition layer in the predetermined region into the voids in the porous structure of the porous layer.

[0084] The first light is preferably laser light, preferably emitted from a solid-state laser. The lower limit of the transmittance of the infrared-absorbing resin composition layer 20 for the first light, i.e., the laser light used, is preferably 5% or more, 10% or more, 20% or more, or 30% or more, and the upper limit is preferably 85% or less, 80% or less, 75% or less, or 70% or less. The infrared-absorbing resin composition layer 20 more preferably has a transmittance for the first light of 20% or more and 75% or less, and even more preferably has a transmittance of 30% or more and 70% or less. By irradiating a predetermined region of the infrared-absorbing resin composition layer 20, which has the property of effectively absorbing laser light, with laser light, the resin composition in the irradiated region can be selectively and efficiently heated. As a result, a first layer 10 is formed having second regions 14 arranged in a relatively high-resolution pattern.

[0085] The spatial intensity distribution of the laser light (beam) preferably has a Gaussian distribution or a top-hat distribution, but is not limited to this. The beam shape may be circular or rectangular. The beam may be focused using a focusing optical system such as an objective lens. When the beam shape is circular, the focal diameter (spot diameter) is preferably, for example, in the range of 10 μm to 150 μm, and more preferably in the range of 30 μm to 100 μm. By setting the focal diameter to 10 μm or more, a sufficient depth of focus can be obtained, thereby stabilizing the process. Furthermore, by setting the focal diameter to 150 μm or less, a decrease in energy density can be suppressed, and the formation of the desired pattern (formation of the second region) can be promoted. Furthermore, by increasing the number of pulses that can be emitted per unit time, the number of patterns that can be formed per unit time increases, leading to improved productivity.

[0086] From the viewpoint of forming a pattern in a short time, it is preferable to use a pulsed laser, and it is preferable to use a laser having a pulse width on the order of nanoseconds to microseconds. If the pulse width is too short, heat generation may not occur, but if the pulse width is within the above range, a photochemical reaction occurs accompanied by heat generation, so that sufficient energy injection time can be achieved and the desired pattern can be formed. Furthermore, if the pulse width is within this range, the formation of one pattern can be completed in a short time, which is preferable from the viewpoint of productivity.

[0087] The repetition frequency of the pulsed laser light is not particularly limited, but from the viewpoint of productivity, the higher the repetition frequency the better, and it can be adjusted appropriately within the range of 10 kHz to 5,000 kHz.

[0088] Examples of types of laser oscillators that satisfy the above requirements include, but are not limited to, YAG lasers, YLF lasers, YVO4 lasers, fiber lasers, and semiconductor lasers.

[0089] The conditions for irradiating the laser beam can be set to any appropriate conditions, but the energy density is preferably 1 J / cm 2 More than 20J / cm 2It is preferable that the energy density is within this range. The energy density is sufficient to form the desired pattern and also to suppress evaporation and thermal decomposition of the irradiated material. The energy density is calculated using the following formula. Energy density [J / cm 2 ] = pulse energy [J] / focus spot area [cm 2 ] (Note that pulse energy [J] = power [W] / repetition frequency [kHz].)

[0090] To achieve high-speed pattern processing, it is preferable to use a scanner unit that uses a galvanometer scanner, a polygon scanner, or a combination of these. By using such a scanner unit, patterns can be formed at a scanning speed of 0.01 m / s to 170 m / s in the scanning direction of the laser light. The pattern pitch can be set arbitrarily by adjusting the repetition frequency of the laser pulse according to the scanning speed, and can be set, for example, in the range of 10 μm to 500 μm.

[0091] The pattern pitch in the direction perpendicular to the scanning direction can be appropriately adjusted by controlling the relative positional relationship between the scanner unit and the object to be irradiated. Such control can be performed using a precision stage with a drive shaft, for example, by adsorbing and fixing a sheet of the object to be irradiated to the stage surface and irradiating it with laser light while feeding it at regular intervals in the direction perpendicular to the scanning direction, thereby forming a pattern at a desired pitch. Alternatively, a pattern can be formed using a scanner unit on a wound, long raw web that is being transported intermittently or continuously by a roll-to-roll transport method. [Example]

[0092] Hereinafter, the embodiments of the present invention will be described in detail with reference to examples, but the embodiments of the present invention are not limited to these examples. The methods for measuring each property are as follows.

[0093] (1) Refractive index After forming a first layer on the acrylic film, it was cut to a size of 50 mm x 50 mm and attached to the surface of a glass plate (thickness: 3 mm) via a pressure-sensitive adhesive layer. The center of the back surface of the glass plate (diameter: approximately 20 mm) was filled in with black marker to create a sample that did not reflect light from 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 500 nm and an incident angle of 50 degrees to 80 degrees.

[0094] (2) Light extraction effect The optical element obtained in Example 1 below was bonded to a 2 mm thick resin plate ("Acrylite EX001" manufactured by Mitsubishi Chemical Corporation) via an acrylic pressure-sensitive adhesive (refractive index 1.47, thickness 5 μm). Light was incident from the edge of the resin plate, and the distribution of light emitted from the main surface of the resin plate was observed visually and with a microscope.

[0095] [Manufacturing Example 1] Preparation of coating liquid (liquid containing microporous particles) for forming porous layer (first region of first layer) and preparation of precursor film (before aging)

[0096] (1) Gelation of silicon compounds Mixture A was prepared by dissolving 0.95 g of methyltrimethoxysilane (MTMS), a precursor of a gel-like silicon compound, in 2.2 g of dimethyl sulfoxide (DMSO). 0.5 g of a 0.01 mol / L aqueous solution of oxalic acid was added to this mixture A, and the mixture was stirred at room temperature for 30 minutes to hydrolyze the MTMS, producing mixture B containing tris(hydroxy)methylsilane.

[0097] To 5.5 g of DMSO, 0.38 g of 28% by mass ammonia water and 0.2 g of pure water were added, and then the above mixed solution B was further added and stirred at room temperature for 15 minutes to gel the tris(hydroxy)methylsilane, thereby obtaining mixed solution C containing a gel-like silicon compound (polymethylsilsesquioxane).

[0098] (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.

[0099] (3) Crushing 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 and 1.15 g of IPA in mixed solution D weighed into a 5 cc screw bottle, and crushed for 2 minutes at 50 W and 20 kHz.

[0100] This grinding process pulverized the gel-like silicon compound in the mixed solution D, resulting in mixed solution D' becoming a sol solution of the pulverized material. The volume average particle size, which indicates the particle size variation of the pulverized material contained in mixed solution D', was measured using a dynamic light scattering Nanotrac particle size analyzer (manufactured by Nikkiso Co., Ltd., Model UPA-EX150) and found to be 0.50 to 0.70. Furthermore, 0.062 g of a 1.5 mass% MEK (methyl ethyl ketone) solution of a photobase generator (Wako Pure Chemical Industries, Ltd.: Product Name WPBG266) and 0.036 g of a 5% MEK solution of bis(trimethoxysilyl)ethane were added to 0.75 g of this sol solution (mixed solution C') to obtain a coating solution for forming a porous layer (a solution containing microporous particles). The coating solution for forming a porous layer contains a porous silica material having silsesquioxane as its basic structure.

[0101] The coating solution was applied (coated) onto the surface of an acrylic resin film (thickness: 40 μm) prepared according to Production Example 1 of JP 2012-234163 A to form a coating film. The coating film was dried by treating at a temperature of 100°C for 1 minute, and then the dried coating film was irradiated with 300 mJ / cm using light with a wavelength of 360 nm. 2 The acrylic resin film was then irradiated with UV light at a light irradiation dose (energy) of 1.15 to obtain a laminate (acrylic film with a porous silica layer) in which a porous layer (a porous silica body formed by chemical bonding of microporous silica particles) was formed on the acrylic resin film. The refractive index of the porous layer was 1.15.

[0102] [Evaluation of optical component shape] In addition to observing the front image of the optical members obtained in the examples using an optical microscope, cross-sectional SEM images were obtained as follows.

[0103] Specifically, the separator was peeled off to expose the dye adhesive surface, and the adhesive surface was coated with Pt-Pd for 10 seconds using a Hitachi High-Technologies magnetron sputtering machine (E-1030). Next, a protective film for FIB processing (formed by carbon deposition) was formed on the adhesive surface at room temperature using a FIB-SEM (Helios G4 UX) manufactured by FEI Corporation, Japan. The sample was then cooled to -160°C in the same machine, and then, while cooled to -160°C, the main surface of the optical component was tilted 52° relative to the focused ion beam and subjected to FIB processing. The cross section formed by FIB processing was then observed using an SEM. FIB-SEM setting conditions Acceleration voltage: FIB 30kV, SEM 2kV Observed image: Backscattered electron image Setting temperature: -160℃

[0104] [Measurement of near-infrared transmittance of pigmented adhesives] With a PET separator (38 μm thick, refractive index 1.57) placed on one of the main surfaces, measurement light was irradiated from the dye adhesive surface, and the transmittance for the wavelength of the laser light used was measured. A Hitachi U-4100 spectrophotometer was used to measure near-infrared transmittance.

[0105] Light extraction effect The separator of the optical element obtained in the following example was peeled off and attached to a 2 mm thick resin plate (Acrylite EX001 manufactured by Mitsubishi Chemical Corporation), and then a textured film was laminated on top of that via water (refractive index 1.33). LED light was incident from the edge of the resin plate, and the light extraction effect was evaluated visually. Figure 6 shows a schematic configuration of a light distribution element sample used to evaluate the light extraction effect. An optical element 100b is placed on a resin plate 50, and a separator 60 is placed on the optical element 100b. A textured film 70 is placed on the separator 60 via water, and the emitted light L E The distribution of was evaluated visually.

[0106] [Manufacturing Example 1] Manufacture of textured film A textured film was produced according to the method described in JP-A-2013-524288. Specifically, the surface of a polymethyl methacrylate (PMMA) film was coated with lacquer (Finecure RM-64 manufactured by Sanyo Chemical Industries, Ltd.), an optical pattern was embossed on the film surface containing the lacquer, and then the lacquer was cured to produce the desired textured film. The total thickness of the textured film was 130 μm, and the haze was 0.8%.

[0107] FIG. 7A shows a plan view of a portion of the produced textured film 70 as seen from the textured surface side. FIG. 7B shows a 7B-7B' cross-sectional view of the textured film of FIG. 7A. A plurality of recesses 74 having a length L of 80 μm, a width W of 14 μm, and a depth H of 10 μm and a triangular cross section were arranged at intervals of width E (155 μm) in the X-axis direction. Furthermore, a pattern of such recesses 74 was arranged at intervals of width D (100 μm) in the Y-axis direction. The density of the recesses 74 on the surface of the textured film was 3612 / cm. 2 7B, θa and θb were both 41°, and the area ratio of the recesses 74 when the film was viewed in plan from the uneven surface side was 4.05%.

[0108] Next, the characteristics of the optical members according to the embodiments of the present invention will be described with reference to Examples 1 to 6 and Comparative Examples 1 and 2. The configurations and properties of the optical members of Examples 1 to 6 and Comparative Examples 1 and 2 are summarized in Table 1.

[0109] [Example 1] The infrared-absorbing resin composition layer (second layer) was a laminated structure of a dye-free adhesive layer (resin composition layer) and a dye layer formed on the adhesive layer. A dye solution was prepared by adding 0.2 parts by mass of a dye-based dye CIR-RL (a phenylenediamine-based diimonium compound) manufactured by Japan Carlit Co., Ltd. to 100 parts by mass of a solvent (MIBK / EtOH / HO, mass ratio 1:9:1).

[0110] One separator of double-sided PSA A (PET separator / acrylic PSA A / PET separator, thickness 38 μm / 10 μm / 38 μm) produced by the method described below was peeled off, and the above dye solution was applied to the exposed acrylic PSA surface to form a film with a wet thickness of 33 μm, which was then dried in a heating oven set to 100°C for 2 minutes to obtain a dye layer. The transmittance of the laminate of the optical adhesive layer and dye layer to laser light with a wavelength of 1064 nm was 49%.

[0111] A laminate of an optical adhesive layer and a dye layer was attached to the main surface of the porous layer of the laminate (acrylic film with a silica porous layer) obtained in Manufacturing Example 1, and the laminate was cut to a 100 mm size to obtain a test piece for producing optical components.

[0112] The obtained test piece was fixed to a vacuum suction stage and irradiated with a near-infrared nanosecond pulse fiber laser under the following conditions to prepare an optical member. Laser oscillator: Jenoptik JenLas fiber ns 20 Wavelength: 1064nm Objective lens: fθ lens (f82mm) Galvanometer scanner: ScanLab intelliScan14 Beam intensity distribution: Gaussian Spot size: φ60μm Repetition frequency: 12.5kHz Scan speed: 2500mm / sec Pattern pitch: 200 μm Power: 5.6W Pulse energy: 448μJ Energy density: 15.8J / cm 2

[0113] When a front image of the obtained optical member was observed with an optical microscope, it was confirmed that second regions of approximately circular shape with a diameter of 50 μm were formed at a pitch of 200 μm.

[0114] When the light extraction effect was evaluated using the light distribution element sample shown in Figure 6, it was confirmed that the LED light was selectively emitted only from the 50 mm x 50 mm area where the second region was formed.

[0115] [Example 2] The infrared-absorbing resin composition layer (second layer) used was acrylic pressure-sensitive adhesive B produced by the method described below. The layer of acrylic pressure-sensitive adhesive B had a transmittance of 41% for laser light with a wavelength of 1064 nm. One separator of double-sided pressure-sensitive adhesive B (PET separator / acrylic pressure-sensitive adhesive B / PET separator, thicknesses 38 μm / 10 μm / 38 μm) was peeled off and attached to the main surface of the porous layer of the laminate (acrylic film with a silica porous layer) obtained in Production Example 1, and a test piece for producing an optical member was produced in the same manner as in Example 1.

[0116] The obtained test piece was fixed to a vacuum suction stage and irradiated with a near-infrared nanosecond pulse fiber laser under the following conditions to prepare an optical member. Laser oscillator: Jenoptik JenLas fiber ns 20 Wavelength: 1064nm Objective lens: fθ lens (f82mm) Galvanometer scanner: ScanLab intelliScan14 Beam intensity distribution: Shaped into a rectangular beam by DOE Spot size: square with one side 60 μm Repetition frequency: 12.5kHz Scan speed: 2500mm / sec Pattern pitch: 200 μm Power: 4.5W Pulse energy: 360μJ Energy density: 10.0J / cm 2

[0117] The obtained optical member was evaluated in the same manner as in Example 1, and it was confirmed that square second regions with a side length of approximately 70 μm were formed at a pitch of 200 μm.

[0118] [Example 3] In Examples 3 to 6 shown below, similar to Example 1, a laminate structure of a dye-free adhesive layer (resin composition layer) and a dye layer formed on the adhesive layer was used as the infrared-absorbing resin composition layer (second layer). In Example 3, a dye solution was prepared by adding 0.52 parts by mass of a dye-based dye CIR-RL (a phenylenediamine-based diimonium compound) manufactured by Nippon Carlit Co., Ltd. to 100 parts by mass of a solvent (MIBK). As in Example 1, one separator of double-sided adhesive A (PET separator / acrylic adhesive A / PET separator, thickness 38 μm / 10 μm / 38 μm) was peeled off, and the dye solution was applied to the exposed surface of the acrylic adhesive to form a film with a wet thickness of 33 μm. The film was then dried in a heating oven set at 100°C for 2 minutes to obtain a dye layer. The transmittance of the laminate of the optical adhesive layer and the dye layer to laser light with a wavelength of 1060 nm was 28%.

[0119] The obtained test piece was fixed to a vacuum suction stage and irradiated with a near-infrared nanosecond pulse fiber laser under the following conditions to prepare an optical member. Laser oscillator: SPI redENERGY G4 Wavelength: 1060nm Scanner: Next Scan Technology LSE310 (f350mm) Beam intensity distribution: Gaussian Spot size: φ55μm Repetition frequency: 500kHz Scanning speed: 50m / sec Pattern pitch: 100 μm Power: 55W Pulse energy: 110μJ Energy density: 4.6J / cm 2

[0120] The obtained optical member was evaluated in the same manner as in Example 1, and it was confirmed that circular second regions with a diameter of about 30 μm were formed at a pitch of 100 μm.

[0121] Furthermore, as can be seen from the cross-sectional SEM image shown in Figure 8, there are almost no voids in the first layer in the second region formed by laser irradiation, whereas many fine voids (pores) are seen in the first layer in the first region.

[0122] [Example 4] In Example 4, a test piece was prepared in the same manner as in Example 3. However, in Example 4, a dye solution was prepared by adding 0.43 parts by mass of a dye-based dye CIR-RL (a phenylenediamine-based diimonium compound) manufactured by Nippon Carlit Co., Ltd. to 100 parts by mass of a solvent (MIBK). The transmittance of the laminate of the optical adhesive layer and the dye layer to laser light with a wavelength of 1060 nm was 37%.

[0123] The obtained test piece was fixed to a vacuum suction stage and irradiated with a near-infrared nanosecond pulse fiber laser under the following conditions to prepare an optical member. Laser oscillator: SPI redENERGY G4 Wavelength: 1060nm Scanner: Next Scan Technology LSE310 (f350mm) Beam intensity distribution: Gaussian Spot size: φ55μm Repetition frequency: 500kHz Scanning speed: 100m / sec Pattern pitch: 200 μm Power: 86W Pulse energy: 172 μJ Energy density: 7.2J / cm 2

[0124] The obtained optical member was evaluated in the same manner as in Example 1, and it was confirmed that circular second regions with a diameter of approximately 42 μm were formed at a pitch of 200 μm.

[0125] [Example 5] In Example 5, the same test piece as in Example 4 was used. The transmittance of the laminate of the optical adhesive layer and the dye layer to laser light with a wavelength of 1060 nm was 37%.

[0126] The obtained test piece was fixed to a vacuum suction stage and irradiated with a near-infrared nanosecond pulse fiber laser under the following conditions to prepare an optical member. Laser oscillator: SPI redENERGY G4 Wavelength: 1060nm Scanner: Next Scan Technology LSE310 (f350mm) Beam intensity distribution: Gaussian Spot size: φ55μm Repetition frequency: 500kHz Scanning speed: 100m / sec Pattern pitch: 200 μm Power: 148W Pulse energy: 296 μJ Energy density: 12.5J / cm 2

[0127] The obtained optical member was evaluated in the same manner as in Example 1, and it was confirmed that circular second regions with a diameter of approximately 99 μm were formed at a pitch of 200 μm. In other words, as a result of using a laser power that was higher than in Example 4, the diameter of the second regions was larger than in Example 4.

[0128] [Example 6] In Example 6, the same test piece as in Example 3 was used. The transmittance of the laminate of the optical adhesive layer and the dye layer to laser light with a wavelength of 1060 nm was 28%.

[0129] The obtained test piece was fixed to a vacuum suction stage and irradiated with a near-infrared nanosecond pulse fiber laser under the following conditions to prepare an optical member. Laser oscillator: SPI redENERGY G4 Wavelength: 1060nm Scanner: Next Scan Technology LSE310 (f350mm) Beam intensity distribution: Gaussian Spot size: φ55μm Repetition frequency: 500kHz Scanning speed: 100m / sec Pattern pitch: 200 μm Power: 86W Pulse energy: 172 μJ Energy density: 7.2J / cm 2

[0130] The obtained optical member was evaluated in the same manner as in Example 1, and it was confirmed that circular second regions with a diameter of approximately 79 μm were formed at a pitch of 200 μm. The laser irradiation conditions were the same as in Example 4, but the transmittance to the laser light was lower than in Example 4, so the diameter of the second regions was larger than in Example 4.

[0131] [Comparative Example 1] Acrylic pressure-sensitive adhesive A (PET separator / acrylic pressure-sensitive adhesive A / PET separator, thickness 38 μm / 10 μm / 38 μm) produced by the method described below was attached to the main surface of the porous layer of the laminate (acrylic film with porous layer) shown in Production Example 1, and then cut to a 100 mm size to obtain a test piece. The transmittance of the layer of acrylic pressure-sensitive adhesive A to laser light with a wavelength of 9400 nm was 42%.

[0132] The test piece was fixed to a vacuum suction stage and irradiated with a CO2 laser under the following conditions to produce an optical member. Laser oscillator: Coherent Diamond J-3 Wavelength: 9.4μm Objective lens: fθ lens (f120mm) Galvanometer scanner: Canon digital galvanometer scanner Beam intensity distribution: Gaussian Focused spot size: φ87μm Z offset: -1.6mm (from focus position) Repetition frequency: 5kHz Scan speed: 1000mm / sec Pattern pitch: 200 μm Power: 5.0W Pulse energy: 1000μJ Energy density: 5.5J / cm 2 (Calculated spot diameter: φ152 μm)

[0133] Observation of the morphology of the obtained optical component using an optical microscope confirmed that a pattern had been formed. Furthermore, when the light extraction effect was verified, it was confirmed that LED light was selectively emitted only from the 50mm x 50mm area where the second region was formed.

[0134] However, the size (diameter) of the formed pattern was 270 μm, which was larger than that of the examples. This is thought to be because the wavelength of the laser light was 9.4 μm, which is in the far-infrared wavelength band, and the pattern size became larger than the irradiated laser spot size due to thermal effects. Furthermore, if the wavelength is long, it is difficult to obtain a smaller spot size due to the wavelength dependency of the spot size.

[0135] Comparative Example 2 In order to obtain a smaller spot, an attempt was made to fabricate an optical component by irradiating the test piece of Comparative Example 1 with a near-infrared nanosecond pulse fiber laser under the following conditions: The transmittance of the layer of acrylic pressure-sensitive adhesive A to laser light with a wavelength of 1064 nm was 89%. Laser oscillator: Jenoptik JenLas fiber ns 20 Wavelength: 1064nm Objective lens: fθ lens (f82mm) Galvanometer scanner: ScanLab intelliScan14 Beam intensity distribution: Shaped into a rectangular beam by DOE Spot size: square with one side 60 μm Repetition frequency: 12.5kHz Scanning speed: 2.5 m / s Pattern pitch: 200 μm Power: 4.5W Pulse energy: 360μJ Energy density: 10.0J / cm 2

[0136] In this case, no pattern was formed, and no light extraction effect was observed. This is thought to be because the transmittance of the adhesive layer of the test piece to the laser light was too high (absorption was too low). Of course, it is possible to form the second region by adjusting the irradiation conditions of the laser light, but this will reduce efficiency and pattern accuracy.

[0137] [Table 1]

[0138] The acrylic adhesives used in the examples and comparative examples were produced by the following method.

[0139] Preparation of acrylic adhesive solution A and fabrication of double-sided adhesive tape A A four-neck flask equipped with a stirring blade, thermometer, nitrogen gas inlet tube, and condenser was charged with 91 parts by weight of butyl acrylate, 7 parts by weight of N-acryloylmorpholine, 3 parts by weight of acrylic acid, 0.3 parts by weight of 2-hydroxybutyl acrylate, 0.1 parts by weight of 2,2'-azobisisobutyronitrile as a polymerization initiator, and 200 parts by weight of ethyl acetate. Nitrogen gas was introduced while gently stirring to replace the atmosphere with nitrogen. The liquid temperature in the flask was maintained at around 55°C, and a polymerization reaction was carried out for 8 hours to prepare an acrylic polymer solution. The mass average molecular weight of the acrylic polymer was 2.2 million.

[0140] Acrylic adhesive solution A was prepared by blending 0.25 parts by mass of dibenzoyl peroxide (1-minute half-life: 130°C) as a crosslinking agent, 0.15 parts of a polyisocyanate crosslinking agent consisting of a trimethylolpropane adduct of tolylene diisocyanate (Coronate L, manufactured by Tosoh Corporation), and 0.1 parts by mass of 3-glycidoxypropyltrimethoxysilane (KBM403, manufactured by Shin-Etsu Silicones Co., Ltd.) as a silane coupling agent per 100 parts by mass of the solids content of the obtained acrylic polymer solution.

[0141] Next, the acrylic pressure-sensitive adhesive solution A was applied to one side of a silicone-treated polyethylene terephthalate (PET) film (manufactured by Mitsubishi Chemical Corporation, thickness: 38 μm) so that the thickness of the adhesive layer after drying would be 10 μm, and the applied adhesive layer was dried for 3 minutes at 150° C. The adhesive layer was then attached to the PET film with the silicone-treated side facing the adhesive layer side, to prepare a double-sided pressure-sensitive adhesive tape.

[0142] Preparation of acrylic adhesive solution B and fabrication of double-sided adhesive tape B Acrylic adhesive solution B was prepared and double-sided adhesive tape B was produced in the same manner as for the preparation of acrylic adhesive solution A and the production of double-sided adhesive tape A, except that in the preparation of the above acrylic adhesive solution A, dibenzoyl peroxide was not used and 0.2 parts by mass of the dye-based pigment CIR-RL (a phenylenediamine-based diimonium compound) manufactured by Japan Carlit Co., Ltd. was added per 100 parts by mass of the solids content of the acrylic polymer solution.

[0143] By using the optical member 100a according to the embodiment of the present invention, for example, the following light distribution element can be obtained.

[0144] FIG. 9 is a schematic cross-section of a light distributing element 200C according to an embodiment of the present invention, and FIG. 10 is a schematic cross-section of a light distributing element 200D according to an embodiment of the present invention.

[0145] 9 includes, in addition to the components of the light distributing element 200A shown in Fig. 2, base material layers 30A, 30B, and 30C, a shaping film 70, and adhesive layers 92, 94, and 96. The shaping film 70 and the adhesive layer 94 form a direction changing layer having a plurality of internal spaces 74.

[0146] 10 includes, in addition to the components of the light distributing element 200A shown in FIG. 2, base material layers 30A, 30B, and 30C, a shaping film 70, a low-refractive index layer 80, and adhesive layers 92, 94, and 96. The low-refractive index layer 80 is formed of a porous layer, for example, similar to the first layer described above. In the light distributing element 200D, the shaping film 70 and the adhesive layer 94 also form a direction conversion layer having a plurality of internal spaces 74.

[0147] The light distribution element 200C shown in Figure 9 emits light incident on the light-guiding layer 50 in an upward direction in the figure, whereas the light distribution element 200D shown in Figure 10 emits light incident on the light-guiding layer 50 in a downward direction in the figure because the light guided from the direction-changing layer is totally internally reflected in the low-refractive-index layer 80.

[0148] In this way, by adopting a configuration in which a laminate layered on multiple base layers is bonded together with an adhesive layer, light distribution elements can be mass-produced using the roll-to-roll method or the roll-to-sheet method.

[0149] The thickness of each of the base layers 30A, 30B, and 30C is, for example, independently 1 μm to 1000 μm, preferably 10 μm to 100 μm, and more preferably 20 μm to 80 μm. The refractive index of each of the base layers 30A, 30B, and 30C is, for example, independently 1.40 to 1.70, and more preferably 1.43 to 1.65.

[0150] The thickness of each of the adhesive layers 92, 94, and 96 is, for example, independently 0.1 μm to 100 μm, preferably 0.3 μm to 100 μm, and more preferably 0.5 μm to 50 μm. The refractive index of each of the adhesive layers 92, 94, and 96 is, independently, preferably 1.42 to 1.60, and more preferably 1.47 to 1.58. The refractive index of each of the adhesive layers 92, 94, and 96 is preferably close to the refractive index of the light guide layer 50 or the shaped film 70 to which it is in contact, and the absolute value of the difference in refractive index is preferably 0.2 or less. [Industrial Applicability]

[0151] The optical member of the present invention is used as a light distribution element together with a light guide layer or the like, and is applicable to public or general lighting such as frontlights, backlights, window / facade lighting, signage, traffic light lighting, window lighting, wall lighting, table lighting, solar applications, decorative illumination, light shields, light masks, and roof lighting. For example, the optical member of the present invention is suitably used as a component of the frontlight of a reflective display, which is an example of signage. Use of the optical member of the present invention makes it possible to view images or graphics on a reflective display without optical defects such as visible blur caused by scattered or diffracted light. [Explanation of symbols]

[0152] 10, 10a, 10b: First layer 12, 12a, 12b: First area 14, 14a, 14b: Second area 20: Second layer 30: Base material layer 50: Light guide layer 60: Base material layer 70: Textured film 74: Recess, internal space 100, 100a, 100b: Optical components 200A, 200B, 200C, 200D: Light distribution element

Claims

1. a first layer having a porous structure; a second layer in contact with the first main surface of the first layer; and the second layer contains a resin composition and has a transmittance of 5% or more and 85% or less for first light in a wavelength range of more than 800 nm and not more than 2000 nm, The optical member, wherein the first layer includes a first region having the porous structure and a second region in which voids in the porous structure are filled with the resin composition.

2. The optical element according to claim 1 , wherein the second layer has adhesive properties.

3. The optical element according to claim 2 , further comprising a release sheet disposed on the second layer opposite to the first layer.

4. The optical member according to claim 1 , wherein the resin composition contains a colorant that absorbs the first light.

5. 5. The optical member according to claim 4, wherein the colorant is a phthalocyanine-based, azo-based, phenylenediamine-based, anthraquinone-based, naphthoquinone-based, and / or cyanine-based colorant.

6. The optical member according to claim 1 , wherein the second layer has a transmittance of 70% or less for the first light.

7. The optical member according to claim 1 , wherein the second layer has a transmittance of 30% or more for the first light.

8. The refractive index of the first region is n １ , the refractive index of the second region is n ２ , the refractive index of the second layer is n ３ When this is the case, n １ <n ２ and n １ <n ３ The optical member according to claim 1 , wherein

9. n １ is 1.30 or less, and n ２ The optical member according to claim 8 , wherein the σ is 1.43 or more.

10. The optical member according to claim 1 , wherein the resin composition contains a photocurable resin.

11. The optical member according to claim 1 , wherein the first layer contains a porous silica material.

12. An optical element described in any one of claims 1 to 11, wherein the diameter of the second region is 100 μm or less.

13. The optical member according to any one of claims 1 to 12; a light guide layer disposed on the first layer side; A light distribution element having:

14. The optical element further includes a light redirecting layer disposed on the opposite side of the light guiding layer. The light distributing element according to claim 13.

15. a first layer having a porous structure and a second layer in contact with a first main surface of the first layer; the second layer comprises a resin composition, a method for producing an optical member, wherein the first layer includes a first region having the porous structure and a second region in which voids in the porous structure are filled with the resin composition, a step A of preparing a laminate including a porous layer having a porous structure and an infrared absorbing resin composition layer that includes a resin composition and has a transmittance of 5% or more and 85% or less for first light in a wavelength range of more than 800 nm and not more than 2000 nm; By selectively irradiating only a predetermined region of the infrared absorbing resin composition layer of the laminate with the first light, a step B of filling voids in the porous structure of the porous layer with a resin composition; The manufacturing method includes the steps of:

16. The manufacturing method according to claim 15 , wherein the infrared absorbing resin composition layer contains the resin composition and a colorant that absorbs the first light.

17. The method according to claim 15 or 16, wherein the step A includes a step A1 of forming the infrared absorbing resin composition layer on the porous layer.

18. The manufacturing method according to claim 17, which relies on claim 16, wherein the step A1 includes a step of forming the infrared absorbing resin composition layer using a material obtained by mixing the resin composition and the colorant.

19. The manufacturing method according to claim 17, which relies on claim 16, wherein the step A1 includes a step of forming a resin composition layer formed from the resin composition, and forming a colorant layer containing the colorant on the resin composition layer.

20. the resin composition contains a photocurable resin, The manufacturing method according to claim 15 , further comprising, after step B, a step of curing the photocurable resin.

21. An optical element described in any one of claims 15 to 20, wherein the diameter of the second region is 100 μm or less.

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