WO2022064782A1 - Optical layered body - Google Patents
Optical layered body Download PDFInfo
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- WO2022064782A1 WO2022064782A1 PCT/JP2021/021923 JP2021021923W WO2022064782A1 WO 2022064782 A1 WO2022064782 A1 WO 2022064782A1 JP 2021021923 W JP2021021923 W JP 2021021923W WO 2022064782 A1 WO2022064782 A1 WO 2022064782A1
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- refractive index
- low refractive
- light guide
- guide plate
- adhesive layer
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F21—LIGHTING
- F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
- F21S2/00—Systems of lighting devices, not provided for in main groups F21S4/00 - F21S10/00 or F21S19/00, e.g. of modular construction
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
Definitions
- the present invention relates to an optical laminate.
- the applicant has developed an optical laminate that can solve such a problem (Patent Document 1).
- the optical laminate has a light guide plate and an optical member laminated on the light guide plate via an adhesive layer, the adhesive layer is formed in a plan view dot pattern, and the density of the dots is the said. It has a gradient that increases from the light entrance side of the light guide plate along the light guide direction, and low refractive index reinforcing portions are provided at both ends of the light guide plate along the light guide direction.
- the optical laminate of Patent Document 1 may leak light in a high humidity environment.
- the present invention has been made to solve the above-mentioned conventional problems, and its main purpose is high brightness, suppression of uneven brightness, excellent strength as an integral body, and light leakage in a high humidity environment. It is an object of the present invention to provide an optical laminate in which the above is suppressed.
- the optical laminate according to the embodiment of the present invention has a light guide plate, an adhesive layer arranged on the light guide plate in a plan view dot pattern, and low refractive index arranged at both ends of the light guide plate along the light guide direction. It has a low refractive index reinforcing portion including a rate portion, and an optical member laminated on the light guide plate via the adhesive layer and the low refractive index reinforcing portion.
- the adhesive layer forms a pattern in which the density of dots increases from the light entrance side of the light guide plate along the light guide direction.
- the surface of the light guide plate on the adhesive layer side and the surface of the optical member on the adhesive layer side In the region where the adhesive layer and the low refractive index reinforcing portion between the light guide plate and the optical member are not arranged, the surface of the light guide plate on the adhesive layer side and the surface of the optical member on the adhesive layer side.
- the low refractive index layer is arranged so as to be in contact with at least one of them.
- the refractive index of the low refractive index portion and the low refractive index layer is 1.30 or less.
- the low refractive index layer is arranged so as to be in contact with both the surface of the light guide plate on the adhesive layer side and the surface of the optical member on the adhesive layer side.
- the low refractive index layer fills the entire region where the adhesive layer and the low refractive index reinforcing portion between the light guide plate and the optical member are not arranged.
- the refractive index of the low refractive index portion and the low refractive index layer is 1.25 or less.
- the low refractive index portion and the low refractive index layer are void layers formed by chemically binding fine pore particles to each other.
- the low refractive index reinforcing portion has a base material, a low refractive index portion formed on the base material, and a pressure-sensitive adhesive layer provided on both sides as an outermost layer.
- the total width of the low refractive index reinforcing portions is 10% or less of the width of the light guide plate. In one embodiment, the total light transmittance of the low refractive index reinforcing portion is 85% or more. In one embodiment, the optical laminate is further provided with a low refractive index reinforcing portion at an end portion of the light guide plate on the side opposite to the light entering side.
- the light guide plate is provided.
- a low refractive index reinforcing portion including a low refractive index portion is provided at both ends along the light guide direction, and the adhesive layer and the low refractive index reinforcing portion between the light guide plate and the optical member are arranged.
- a low refractive index layer is provided so as to be in contact with at least one of the surface of the light guide plate on the adhesive layer side and the surface of the optical member on the adhesive layer side, and the refraction of the low refractive index portion and the low refractive index layer is further provided.
- FIG. 3 is a schematic plan view showing a state in which the optical member of the optical laminate of FIG. 1A is removed. It is a schematic sectional drawing which shows an example of the low refractive index reinforcing part used in the optical laminated body by embodiment of this invention.
- FIG. 1A is a schematic cross-sectional view of an optical laminate according to one embodiment of the invention
- FIG. 1B is a schematic cross-sectional view of an optical laminate according to another embodiment of the invention
- FIG. 1C is a schematic cross-sectional view of an optical laminate according to still another embodiment of the present invention
- FIG. 2 is a schematic plan view showing a state in which the optical member of the optical laminate of FIG. 1A is removed.
- the optical laminate 100 of FIG. 1A has a light guide plate 10, an adhesive layer 20 arranged on the light guide plate 10 in a plan view dot pattern, and a low refractive index arranged at both ends of the light guide plate 10 along the light guide direction.
- the adhesive layer 20 forms a pattern in which the density of dots increases from the light entrance side of the light guide plate along the light guide direction (direction from the left side to the right side of the drawing).
- the brightness can be increased and uneven brightness (the brightness is different between the portion near the incoming light side and the portion far from the incoming light side) can be remarkably suppressed.
- such an adhesive layer has a non-uniform adhesive strength (specifically, the adhesive strength on the incoming light side is small and the adhesive strength on the opposite side to the incoming light side is large), and as a result, the optical lamination is performed. The strength as an integral part of the body becomes insufficient.
- the low refractive index reinforcing portion sufficient strength as an integral body of the optical laminate can be realized.
- the low refractive index reinforcing portion used in the embodiment of the present invention has the following advantages: (1) Since the refractive index of the reinforcing portion itself is low, the efficiency of light utilization is not reduced (as a result). It is possible to secure the strength of the optical laminate as an integral body (while maintaining high brightness and suppressing uneven brightness); (2) Since it can be formed into an elongated shape, the optical laminate is applied. The effect on the display area of the image display device can be minimized.
- the light guide plate 10 is located in a region (that is, a gap portion in the optical laminate) in which the adhesive layer 20 and the low refractive index reinforcing portion 40 are not arranged between the light guide plate 10 and the optical member 30.
- the low refractive index layer 50 is arranged so as to be in contact with at least one of the surface on the adhesive layer 20 side and the surface on the adhesive layer 20 side of the optical member 30. In one embodiment, the low refractive index layer 50 is arranged so as to be in contact with both the surface of the light guide plate 10 on the adhesive layer 20 side and the surface of the optical member 30 on the adhesive layer 20 side. In the example shown in FIG.
- the low refractive index layer 50 is the entire region (that is, in the optical laminate) in which the adhesive layer 20 between the light guide plate 10 and the optical member 30 and the low refractive index reinforcing portion 40 are not arranged. It fills the entire gap).
- Applicants have a light guide plate, an adhesive layer arranged on the light guide plate in a pattern such that the dot density increases from the light entrance side of the light guide plate along the light guide direction, and along the light guide direction of the light guide plate.
- an optical laminate having low refractive index reinforcing portions arranged at both ends and an optical member laminated on a light guide plate via an adhesive layer and a low refractive index reinforcing portion.
- Such an optical laminate has high luminance, suppresses luminance unevenness, and has excellent strength as an integral body.
- the present inventors have discovered a new problem that light leakage may occur in such an optical laminate in a high humidity environment, and the light leakage is a light guide plate in a high humidity environment. It has been found that this is caused by dew condensation that occurs in the region (void portion) where the adhesive layer and the low refractive index reinforcing portion between the optical member and the optical member are not arranged.
- the present inventors have provided a low refractive index layer in the void portion, so that dew condensation is maintained while maintaining the excellent characteristics of the optical laminate by the present applicant.
- the void portion when the low refractive index layer fills the void portion, the void portion is substantially eliminated, so that dew condensation can be remarkably suppressed, and as a result, light leakage can be remarkably suppressed.
- the difference in the refractive index from the void portion air portion, refractive index 1.00
- the light utilization efficiency is not substantially lowered, it is possible to maintain the excellent characteristics of the optical laminate, that is, the brightness is maintained high and the brightness unevenness is suppressed.
- the following advantages can also be obtained.
- the presence of a gap may cause the light guide plate and the optical member to come into contact with each other, resulting in light leakage due to the contact.
- the contact can be avoided, so that light leakage due to such a mechanism can be suppressed.
- the low refractive index layer 50 may be arranged so as to be in contact with both the surface of the light guide plate on the adhesive layer side and the surface of the optical member on the adhesive layer side, or may fill the void portion as shown in FIG. 1A. It may be arranged so as to be in contact with only the surface of the optical member 30 on the adhesive layer 20 side as shown in FIG. 1B, and may be arranged so as to be in contact with only the surface of the light guide plate 10 on the adhesive layer 20 side as shown in FIG. 1C. It may be arranged in. In either configuration, dew condensation and / or contact between the light guide plate and the optical member can be suppressed, and as a result, light leakage can be suppressed. Preferably, it is the configuration of FIG. 1A. This is because it has an effect of suppressing dew condensation itself (as a result, a light leakage suppressing effect).
- the ratio of the thickness of the low refractive index layer 50 to the thickness of the void portion or the adhesive layer 20 is not particularly limited as long as light leakage can be suppressed.
- the light guide plate 10 may be typically made of a resin (preferably transparent resin) film or plate-like material, or glass.
- resins include thermoplastic resins and reactive resins (for example, ionizing radiation curable resins).
- thermoplastic resin include (meth) acrylic resins such as polymethyl methacrylate (PMMA) and polyacrylonitrile, polyester resins such as polycarbonate (PC) resin and PET, and cellulose-based resins such as triacetyl cellulose (TAC). Examples thereof include resins, cyclic polyolefin resins, and styrene resins.
- ionizing radiation curable resin include epoxy acrylate-based resin and urethane acrylate-based resin. These resins may be used alone or in combination of two or more.
- the thickness of the light guide plate can be, for example, 100 ⁇ m to 100 mm.
- the thickness of the light guide plate is preferably 50 mm or less, more preferably 30 mm or less, and further preferably 10 mm or less.
- the refractive index of the light guide plate is preferably 1.47 or more, more preferably 1.47 to 1.60, and further preferably 1.47 to 1.55.
- the difference between the refractive index of the light guide plate and the refractive index of the low refractive index layer of the low refractive index reinforcing portion is preferably 0.22 or more, more preferably 0.22 to 0.40, and further preferably 0. It is .25 to 0.35.
- the refractive index of the light guide plate can be adjusted by appropriately selecting the constituent material of the light guide plate.
- the adhesive layer 20 is formed of a dot pattern in a plan view, and has a gradient such that the density of dots increases from the light entrance side of the light guide plate along the light guide direction.
- the gradient of the dot density may change continuously along the light guide direction as shown in FIG. 2, or may change stepwise for each predetermined region along the light guide direction.
- the dot density (average) in the region from the end on the light entering side to 10% in the length direction of the light guide plate is preferably 0% to 50%, and the light guide plate is from the end opposite to the light entrance side.
- the dot density (average) of the region up to 10% in the length direction is preferably 50% to 100%.
- the adhesive layer may be composed of an adhesive or an adhesive.
- the adhesive layer is composed of an adhesive. This is because pattern formation is easy. By using an adhesive, pattern formation can be performed by inkjet, printing, or the like.
- any suitable adhesive can be used.
- it is an active energy ray (for example, ultraviolet light, visible light) curable adhesive.
- the active energy ray-curable adhesive include acrylic adhesives, epoxy adhesives, vinyl adhesives, thiol adhesives, urethane adhesives, and silicone adhesives.
- the active energy ray-curable adhesive and the thermosetting adhesive may be used in combination.
- the pressure-sensitive adhesive include a pressure-sensitive adhesive having a high elastic modulus.
- the thickness of the adhesive layer may be, for example, 50 ⁇ m or more, 60 ⁇ m or more, 70 ⁇ m or more, 80 ⁇ m or more, 90 ⁇ m or more, or 100 ⁇ m or more, and may be 1000 ⁇ m or less, 900 ⁇ m or less, 800 ⁇ m or less, 700 ⁇ m or less, 600 ⁇ m or less, or 500 ⁇ m or less.
- optical member 30 examples include any suitable optical member that can be laminated with the light guide plate.
- Specific examples of the optical member include a reflector, a diffuser, a prism sheet, a polarizing plate, a retardation film, a conductive film, a substrate, an image display cell, or an image display panel.
- the low refractive index reinforcing portion 40 is provided at both ends of the light guide plate along the light guide direction as described above. Any suitable shape can be adopted as the plan view shape of the low refractive index reinforcing portion 40. Specifically, the low refractive index reinforcing portion may be formed continuously or intermittently along the light guide direction of the light guide plate as shown in FIG. When the low refractive index reinforcing portion is continuously formed, the low refractive index reinforcing portion may be, for example, an elongated rectangular shape as shown in FIG. 2, a tapered shape, or a trapezoidal shape. May be.
- the low refractive index reinforcing portion may have a shape that narrows toward the incoming light side or a shape that narrows toward the opposite side to the incoming light side. good.
- the low index of refraction reinforcement may be, for example, rectangular, dot, or any other shape (eg, triangle, square). , Polygon, semi-circular).
- the length of the low refractive index reinforcing portion (that is, the length along the light guide direction) is preferably 50% or more, more preferably 60% or more, respectively, with respect to the total length of the light guide plate in the light guide direction.
- the upper limit of the length of the low refractive index reinforcing portion is 100% with respect to the total length of the light guide plate in the light guide direction. That is, the low refractive index reinforcing portion may be provided over the entire light guide direction of the light guide plate. If the length is within such a range, a sufficient reinforcing effect (that is, the strength of the optical laminate as an integral body) can be realized.
- the length of the low refractive index reinforcing portion is the sum of the respective lengths. Further, the lengths of the low refractive index reinforcing portions may be the same or different.
- the width of the low refractive index reinforcing portion (that is, the length along the direction orthogonal to the light guide direction) is preferably 5% or less with respect to the width of the light guide plate, respectively.
- the total width of the low refractive index reinforcing portions is preferably 10% or less, more preferably 9% or less with respect to the width of the light guide plate.
- the total width of the low refractive index reinforcing portions may be, for example, 1% or more.
- the total light transmittance of the low refractive index reinforcing portion is preferably 85% or more, more preferably 90% or more. When the total light transmittance is within such a range, the strength of the optical laminate as an integral body can be ensured without adversely affecting the display area of the image display device to which the optical laminate is applied.
- the low refractive index reinforcing portions may be provided at both ends of the light guide plate along the light guide direction, or may be provided inside at a certain distance from both ends.
- the low refractive index reinforcing portion is provided at both ends or in the vicinity thereof along the light guide direction of the light guide plate. With such a configuration, the influence on the display area can be minimized.
- the low refractive index reinforcing portion When the low refractive index reinforcing portion is continuously formed, the low refractive index reinforcing portion may be provided at the center of the light guide plate in the light guide direction, and the low refractive index reinforcing portion may be provided at a biased position (for example, the incoming light side, the incoming light side). It may be provided on the opposite side).
- the respective arrangement densities may be uniform over the entire light guide direction or may change along the light guide direction.
- the low refractive index reinforcing portions may be provided at both ends of the light guide plate along the light guide direction. Therefore, the low refractive index reinforcing portion may be provided at any appropriate position other than the above-mentioned position. In one embodiment, the low refractive index reinforcing portion may be further provided at the end portion of the light guide plate on the side opposite to the light entering side. With such a configuration, a further reinforcing effect can be obtained.
- FIG. 3 is a schematic cross-sectional view showing an example of a low refractive index reinforcing portion.
- the low refractive index reinforcing portion 40 has a base material 41, a low refractive index portion 42 formed on the base material 41, and adhesive layers 43 and 44 provided as outermost layers on both sides. That is, the low refractive index reinforcing portion is configured as a double-sided tape, and the light guide plate and the optical member are bonded to each other by the adhesive layers on both sides.
- the low refractive index section 42 is substantially a low refractive index layer, but in the present specification, it is referred to as a low refractive index section in order to easily distinguish it from the low refractive index layer 50. Refer to.
- the base material 41 can be typically composed of a film or a plate-like material of a resin (preferably a transparent resin).
- resins include thermoplastic resins and reactive resins (for example, ionizing radiation curable resins).
- thermoplastic resin include (meth) acrylic resins such as polymethyl methacrylate (PMMA) and polyacrylonitrile, polyester resins such as polycarbonate (PC) resin and PET, and cellulose-based resins such as triacetyl cellulose (TAC). Examples thereof include resins, cyclic polyolefin resins, and styrene resins.
- the ionizing radiation curable resin include epoxy acrylate-based resin and urethane acrylate-based resin. These resins may be used alone or in combination of two or more.
- the thickness of the base material is, for example, 10 ⁇ m to 100 ⁇ m, preferably 10 ⁇ m to 50 ⁇ m.
- the refractive index of the base material is preferably 1.47 or more, more preferably 1.47 to 1.60, and further preferably 1.47 to 1.55. Within such a range, the light can be guided to the image display cell without adversely affecting the light extracted from the light guide plate.
- the low refractive index portion typically has a void inside.
- the porosity of the low refractive index portion is typically 50% by volume or more, preferably 70% by volume or more, and more preferably 80% by volume or more. On the other hand, the porosity is, for example, 90% by volume or less, preferably 85% by volume or less. When the porosity is within the above range, the refractive index of the low refractive index portion can be set within an appropriate range.
- the porosity is a value obtained by calculating the porosity from the value of the refractive index measured by the ellipsometer from the Lorentz-Lorenz's formula (Lorentz-Lorenz's formula).
- the refractive index of the low refractive index portion is preferably 1.25 or less, more preferably 1.20 or less, and further preferably 1.15 or less.
- the lower limit of the refractive index can be, for example, 1.01. Within such a range, it is possible to realize extremely excellent light utilization efficiency in the laminated structure of the light guide plate and the optical member obtained through the low refractive index reinforcing portion.
- Refractive index refers to the refractive index measured at a wavelength of 550 nm unless otherwise specified.
- the refractive index is a value measured by the method described in "(I) Refractive index of the low refractive index portion of the low refractive index layer and the low refractive index reinforcing portion" of the following Example.
- the low refractive index portion may be preferably formed by coating, printing or the like.
- the material constituting the low refractive index portion for example, the materials described in International Publication No. 2004/113966, JP2013-254183A, and JP2012-189802 can be adopted.
- silica-based compounds for example, silica-based compounds; hydrolyzable silanes and / or silsesquioxane, and partial hydrolysates and dehydration condensates thereof; organic polymers; silicon compounds containing silanol groups; silicates.
- Active silica obtained by contact with an acid or ion exchange resin; polymerizable monomer (eg, (meth) acrylic monomer, and styrene monomer); curable resin (eg, (meth) acrylic resin, fluorine-containing resin). , And urethane resin); and combinations thereof.
- the low refractive index portion can be formed by applying or printing a solution or dispersion of such a material.
- the size of the void (hole) in the low refractive index portion shall indicate the diameter of the major axis among the diameter of the major axis and the diameter of the minor axis of the void (hole).
- the size of the voids (pores) is, for example, 2 nm to 500 nm.
- the size of the voids (pores) is, for example, 2 nm or more, preferably 5 nm or more, more preferably 10 nm or more, and further preferably 20 nm or more.
- the size of the void (pore) is, for example, 500 nm or less, preferably 200 nm or less, and more preferably 100 nm or less.
- the size range of the voids (pores) is, for example, 2 nm to 500 nm, preferably 5 nm to 500 nm, more preferably 10 nm to 200 nm, and even more preferably 20 nm to 100 nm.
- the size of the void (hole) can be adjusted to a desired size according to the purpose, application, and the like.
- the size of the voids (pores) can be quantified by the BET test method.
- the size of the void (hole) can be quantified by the BET test method. Specifically, 0.1 g of a sample (formed void layer) was put into the capillary of a specific surface area measuring device (manufactured by Micromeritic Co., Ltd .: ASAP2020), and then dried under reduced pressure at room temperature for 24 hours to allow voids. Degas the gas in the structure. Then, by adsorbing nitrogen gas to the sample, an adsorption isotherm is drawn and the pore distribution is obtained. Thereby, the void size can be evaluated.
- a specific surface area measuring device manufactured by Micromeritic Co., Ltd .: ASAP2020
- the haze of the low refractive index portion is, for example, less than 5%, preferably less than 3%.
- the haze is, for example, 0.1% or more, preferably 0.2% or more.
- the range of haze is, for example, 0.1% or more and less than 5%, preferably 0.2% or more and less than 3%.
- the haze can be measured by, for example, the following method.
- the haze is an index of transparency of the low refractive index portion.
- the void layer (low refractive index portion) is cut into a size of 50 mm ⁇ 50 mm and set in a haze meter (manufactured by Murakami Color Technology Research Institute: HM-150) to measure haze.
- Examples of the low refractive index portion having voids inside include a low refractive index portion having a porous layer and / or an air layer in at least a part thereof.
- the porous layer typically includes airgel and / or particles (eg, hollow fine particles and / or porous particles).
- the low refractive index portion may be preferably a nanoporous layer (specifically, a porous layer having a diameter of 90% or more of micropores in the range of 10-1 nm to 103 nm).
- any suitable particles can be adopted.
- the particles are typically composed of silica-based compounds.
- the shape of the particles includes, for example, spherical, plate-like, needle-like, string-like, and grape tuft-like.
- As the string-shaped particles for example, a particle in which a plurality of particles having a spherical, plate-like, or needle-like shape are connected in a bead shape, and a staple-like particle (for example, Japanese Patent Application Laid-Open No. 2001-188104) are described. Short fibrous particles), and combinations thereof.
- the string-shaped particles may be linear or branched.
- Examples of the tufted particles of grape include those in which a plurality of spherical, plate-shaped, and needle-shaped particles are aggregated to form a tuft of grape.
- the shape of the particles can be confirmed, for example, by observing with a transmission electron microscope.
- the thickness of the low refractive index portion is preferably 0.2 ⁇ m to 5 ⁇ m, and more preferably 0.3 ⁇ m to 3 ⁇ m. If the thickness of the low refractive index portion is within such a range, the damage prevention effect becomes remarkable. Further, the desired thickness ratio can be easily realized.
- the low refractive index portion of the present embodiment is composed of one or a plurality of types of structural units that form a fine void structure, and the structural units are chemically bonded to each other via catalytic action.
- Examples of the shape of the structural unit include a particle shape, a fibrous shape, a rod shape, and a flat plate shape.
- the structural unit may have only one shape, or may have a combination of two or more shapes. In the following, a case where the low refractive index portion is mainly a void layer of a porous body in which the fine pore particles are chemically bonded to each other will be described.
- Such a void layer can be formed, for example, by chemically bonding fine pore particles to each other in the void layer forming step.
- the shape of the "particle" (for example, the fine pore particles) is not particularly limited, and may be spherical or another shape, for example.
- the fine pore particles may be, for example, sol-gel beaded particles, nanoparticles (hollow nanosilica / nanoparticles), nanoparticles and the like.
- the micropore particles typically contain inorganic substances. Specific examples of the inorganic substance include silicon (Si), magnesium (Mg), aluminum (Al), titanium (Ti), zinc (Zn), and zirconium (Zr).
- the micropore particles are, for example, micropore particles of a silicon compound
- the porous body also includes, for example, a silicone porous body (silica and / or a porous body containing silsesquioxane as a constituent unit).
- the fine pore particles of the silicon compound include, for example, a pulverized body of a gel-like silica compound.
- the low refractive index portion having a porous layer and / or an air layer at least in a part thereof, for example, it is made of a fibrous substance such as nanofibers, and the fibrous substances are entangled to form voids. There is a layered void layer.
- the method for producing such a void layer is not particularly limited, and is the same as, for example, in the case of a porous void layer in which the fine pore particles are chemically bonded to each other.
- Still another form includes a void layer using hollow nanoparticles and nanoclay, and a void layer formed by using hollow nanoballoons and magnesium fluoride.
- the void layer may be a void layer composed of a single constituent substance, or may be a void layer composed of a plurality of constituent substances.
- the void layer may be composed of the single above-mentioned form, or may be composed of a plurality of the above-mentioned forms.
- the porous structure of the porous body can be, for example, a continuous foam structure having a continuous pore structure.
- the continuous foam structure means that, for example, in the above-mentioned silicone porous body, the pore structures are three-dimensionally connected, and it can be said that the internal voids of the pore structure are continuous. Since the porous body has a continuous foam structure, it is possible to increase the porosity. However, when using single-foam particles (particles having individual pore structures) such as hollow silica, a continuous-foam structure cannot be formed.
- the coating film (crushed product of gel-like silicon compound) is included because the particles have a three-dimensional dendritic structure.
- the dendritic particles settle and deposit in the sol coating film), so that a continuous foam structure can be easily formed.
- the low refractive index portion more preferably has a monolithic structure in which the continuous foam structure includes a plurality of pore distributions.
- the monolith structure means, for example, a hierarchical structure including a structure in which nano-sized fine voids are present and a continuous bubble structure in which the nano-voids are aggregated.
- a monolith structure for example, it is possible to impart a high porosity to coarse continuous bubble voids while imparting film strength to fine voids, and to achieve both film strength and high porosity.
- a monolith structure can be preferably formed by controlling the pore distribution of the void structure formed in the gel (gel-like silicon compound) before pulverizing into silica sol particles.
- a monolith structure can be formed by controlling the particle size distribution of the silica sol particles after pulverization to a desired size.
- the low refractive index portion contains, for example, a pulverized product of a gel-like compound as described above, and the pulverized products are chemically bonded to each other.
- the form of the chemical bond (chemical bond) between the pulverized substances in the low refractive index portion is not particularly limited, and examples thereof include a crosslink bond, a covalent bond, and a hydrogen bond.
- the volume average particle size of the pulverized product in the low refractive index portion is, for example, 0.10 ⁇ m or more, preferably 0.20 ⁇ m or more, and more preferably 0.40 ⁇ m or more.
- the volume average particle diameter is, for example, 2.00 ⁇ m or less, preferably 1.50 ⁇ m or less, and more preferably 1.00 ⁇ m or less.
- the range of the volume average particle diameter is, for example, 0.10 ⁇ m to 2.00 ⁇ m, preferably 0.20 ⁇ m to 1.50 ⁇ m, and more preferably 0.40 ⁇ m to 1.00 ⁇ m.
- the particle size distribution can be measured by, for example, a particle size distribution evaluation device such as a dynamic light scattering method or a laser diffraction method, and an electron microscope such as a scanning electron microscope (SEM) or a transmission electron microscope (TEM).
- SEM scanning electron microscope
- TEM transmission electron microscope
- the type of gel compound is not particularly limited.
- examples of the gel-like compound include a gel-like silicon compound.
- the contained silicon atom is siloxane bonded.
- the proportion of unbonded silicon atoms (that is, residual silanol) in the total silicon atoms contained in the void layer is, for example, less than 50%, preferably 30% or less, and more preferably 15%. It is as follows.
- This method is typically a precursor forming step of forming a void structure which is a precursor of a low refractive index portion (void layer) on a resin film, and a crosslinking reaction inside the precursor after the precursor forming step. Includes a cross-linking reaction step, which causes The method is a step of preparing a containing liquid for producing a containing liquid containing fine pore particles (hereinafter, may be referred to as "fine pore particle-containing liquid" or simply “containing liquid”), and a drying process for drying the containing liquid. Further including a step, in the precursor forming step, the fine pore particles in the dried body are chemically bonded to each other to form a precursor.
- the containing liquid is not particularly limited, and is, for example, a suspension containing fine pore particles.
- the fine pore particles are mainly pulverized gel-like compounds and the void layer is a porous body containing the pulverized gel-like compound (preferably a silicone porous body) will be described.
- the low refractive index portion can be similarly formed even when the fine pore particles are other than the pulverized product of the gel-like compound.
- a low refractive index portion (void layer) having a very low refractive index is formed.
- the reason is presumed as follows, for example. However, the guess does not limit the method of forming the low refractive index portion.
- the crushed product is a crushed gel-like silicon compound
- the three-dimensional structure of the gel-like silicon compound before crushing is dispersed in the three-dimensional basic structure.
- a crushed product of a gel-like silicon compound is applied onto a resin film to form a precursor having a porous structure based on a three-dimensional basic structure. That is, according to the above method, a new porous structure (three-dimensional basic structure) is formed by coating the pulverized material, which is different from the three-dimensional structure of the gel-like silicon compound. Therefore, in the finally obtained void layer, it is possible to realize a low refractive index that functions to the same extent as, for example, an air layer. Further, in the above method, the three-dimensional basic structure is immobilized because the crushed substances are chemically bonded to each other. Therefore, the finally obtained void layer can maintain sufficient strength and flexibility even though it has a structure having voids.
- any suitable adhesive may be used.
- the pressure-sensitive adhesive include an acrylic pressure-sensitive adhesive (acrylic pressure-sensitive adhesive composition). Since the acrylic pressure-sensitive adhesive composition is well known in the industry, detailed description thereof will be omitted.
- the thickness of the pressure-sensitive adhesive layer is, for example, 3 ⁇ m to 200 ⁇ m.
- the constituent materials and thicknesses of the pressure-sensitive adhesive layers 43 and 44 may be the same or different, respectively.
- the pressure-sensitive adhesive layer is typically a low-refractive index portion when the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer is in a normal state. It has a hardness that does not penetrate the voids.
- the storage elastic modulus of such a pressure-sensitive adhesive layer can be, for example, 1.3 ⁇ 10 5 (Pa) to 1.0 ⁇ 10 7 (Pa).
- Low Refractive Index Layer The detailed configuration of the low refractive index layer 50 is basically as described in Section E-3 with respect to the low refractive index portion of the low refractive index reinforcing portion. Hereinafter, only the configuration characteristic of the low refractive index layer will be described.
- the thickness of the low refractive index layer is the same as the thickness of the adhesive layer, for example, 50 ⁇ m or more, 60 ⁇ m or more, 70 ⁇ m or more, 80 ⁇ m or more, 90 ⁇ m or more. , Or 100 ⁇ m or more, and can be 1000 ⁇ m or less, 900 ⁇ m or less, 800 ⁇ m or less, 700 ⁇ m or less, 600 ⁇ m or less, or 500 ⁇ m or less. Further, in the case of the configuration of FIG.
- the thickness of the low refractive index layer is not particularly limited as long as light leakage can be suppressed, but the lower limit thereof is preferably 0.6 ⁇ m or more, 0.75 ⁇ m or more, 0.80 ⁇ m or more.
- the upper limit thereof is preferably 3 ⁇ m or less and 2 ⁇ m or less.
- the size of the voids (pores) in the low refractive index layer is preferably 400 nm or less, more preferably 300 nm or less, still more preferably 200 nm or less, and particularly preferably 100 nm or less.
- the size of the voids (pores) in the low refractive index layer is within such a range, the infiltration of water can be satisfactorily suppressed, so that dew condensation can be satisfactorily suppressed. As a result, light leakage can be satisfactorily suppressed.
- the smaller the size of the void (pore), the more preferable, and the lower limit thereof can be, for example, 2 nm.
- Luminance unevenness With respect to the optical laminates obtained in Examples and Comparative Examples, LED light was incident from the end of the light guide plate of the optical laminate, and the luminance unevenness was visually observed. It was evaluated according to the following criteria. ⁇ : Luminance (brightness) is uniform over the entire surface of the laminate ⁇ : Light leakage is observed, the brightness is non-uniform, and / or there are few bright regions (III) Intensity Obtained in Examples and Comparative Examples.
- IPA isopropyl alcohol
- the mixture C was lightly stirred and then allowed to stand at room temperature for 6 hours to decant the solvent and catalyst in the gel.
- the same decantation treatment was carried out three times to replace the solvent, and a mixed solution D was obtained.
- the gelled silicon compound in the mixed solution D was pulverized (high pressure medialess pulverization).
- a homogenizer manufactured by SMTE, trade name “UH-50” was used, and 1.85 g of the gel compound and IPA in the mixed solution D were placed in a 5 cc screw bottle.
- the mixture was pulverized for 2 minutes under the conditions of 50 W and 20 kHz.
- the gelled silicon compound in the mixed solution D was pulverized, so that the mixed solution D'became a sol solution of the pulverized product.
- the volume average particle size showing the variation in the particle size of the pulverized material contained in the mixed solution D' was confirmed by a dynamic light scattering type nanotrack particle size analyzer (UPA-EX150 type manufactured by Nikkiso Co., Ltd.) and found to be 0.50 to. It was 0.70.
- the acrylic pressure-sensitive adhesive solution was applied to one side of a polyethylene terephthalate (PET) film (manufactured by Mitsubishi Chemical Polyester Film Co., Ltd., thickness: 38 ⁇ m) treated with silicone, and the thickness of the pressure-sensitive adhesive layer after drying was predetermined. It was applied to a thickness and dried at 150 ° C. for 3 minutes to form an adhesive layer.
- PET polyethylene terephthalate
- the pressure-sensitive adhesive layer formed in Production Example 3 on both sides of the laminate of the base material / low refractive index portion (thickness of the pressure-sensitive adhesive layer on the low-refractive index portion side is 10 ⁇ m, thickness of the pressure-sensitive adhesive layer on the base material side is 75 ⁇ m).
- Thickness of the pressure-sensitive adhesive layer on the low-refractive index portion side is 10 ⁇ m
- thickness of the pressure-sensitive adhesive layer on the base material side is 75 ⁇ m.
- Example 1 The coating liquid A for forming a low refractive index layer prepared in Production Example 1 is coated and dried on a light guide plate (acrylic plate, thickness 400 ⁇ m, total length 85 mm in the light guide direction, width 60 mm, refractive index 1.49). , A low refractive index layer (refractive index 1.18, thickness 1 ⁇ m) was formed. Next, the low refractive index layer was cut with an iron rod (tip of 100 ⁇ m or less) to form a dot pattern.
- a light guide plate (acrylic plate, thickness 400 ⁇ m, total length 85 mm in the light guide direction, width 60 mm, refractive index 1.49).
- a low refractive index layer reffractive index 1.18, thickness 1 ⁇ m
- the low refractive index layer was cut with an iron rod (tip of 100 ⁇ m or less) to form a dot pattern.
- both ends of the low refractive index layer along the light guide direction were removed with a spatula, and the laminate with the double-sided pressure-sensitive adhesive layer produced in Production Example 4 was attached to the removed portions to form a low refractive index reinforcing portion.
- an epoxy adhesive manufactured by Toagosei Corporation, product name "LCR0632" was printed by inkjet on the portion where the dot pattern was formed to form an adhesive layer having a pattern as shown in FIG.
- An optical laminate was produced by laminating a prism film on a light guide plate via a low refractive index reinforcing portion and an adhesive layer.
- the thickness of the low refractive index reinforcing portion and the thickness of the adhesive layer were the same (115.9 ⁇ m). Further, the obtained optical laminate corresponds to the configuration shown in FIG. 1C. The obtained optical laminate was subjected to the evaluations (II) to (IV) above. The results are shown in Table 1.
- Example 2 A low refractive index layer (refractive index 1.25, thickness 1 ⁇ m) was formed by using the low refractive index layer forming coating liquid B prepared in Production Example 2 instead of the low refractive index layer forming coating liquid A.
- An optical laminate was produced in the same manner as in Example 1 except for the above. The obtained optical laminate was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
- Example 3 The laminate with the double-sided adhesive layer produced in Production Example 4 was bonded to both ends of the light guide plate along the light guide direction in the same manner as in Example 1 to form a low refractive index reinforcing portion. Further, the coating liquid A for forming the low refractive index layer A was applied and dried on the light guide plate to form a low refractive index layer having the same thickness (115.9 ⁇ m) as the low refractive index reinforcing portion. Then, an epoxy adhesive (manufactured by Toagosei Co., Ltd., product name "LCR0632”) was printed on a dot pattern similar to that in Example 1 by inkjet to form an adhesive layer.
- an epoxy adhesive manufactured by Toagosei Co., Ltd., product name "LCR0632
- the printed adhesive was infiltrated into the low refractive index layer to fill the voids in the low refractive index layer, and then a prism film was bonded over the prism film to obtain an optical laminate.
- the obtained optical laminate corresponds to the configuration of FIG. 1A.
- the obtained optical laminate was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
- Example 2 An optical laminate was produced in the same manner as in Example 1 except that the low refractive index reinforcing portion was not provided. The obtained optical laminate was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
- the optical laminate of the present invention can be suitably used for an optical device (for example, an image display device, a lighting device) that extracts light by using a light guide plate.
- an optical device for example, an image display device, a lighting device
- Light guide plate 20
- Adhesive layer 30
- Optical member 40
- Low refractive index reinforcing part 41
- Base material 42
- Low refractive index part 50
- Low refractive index layer 100
- Optical laminated body 101 Optical laminated body 102
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Abstract
Provided is an optical layered body which has high brightness, is suppressed in brightness unevenness, and has excellent strength as an integrated product, and in which light leakage under a high-humidity environment is suppressed. The optical layered body according to an embodiment of the present invention is provided with: a light guide plate; an adhesive layer disposed in the light guide plate in a dot pattern in a plan view; a low-refractive index reinforcing portion that includes a low-refractive index part and that is disposed in both end portions of the light guide plate along the light-guiding direction; and an optical member layered on the light guide plate with the adhesive layer and the low-refractive index reinforcing portion interposed therebetween. The adhesive layer has formed therein a pattern such that the density of dots increases from a light-entering side of the light guide plate along the light-guiding direction thereof. In an area which is between the light guide plate and the optical member and in which the adhesive layer and the low-refractive index reinforcing portion are not disposed, a low-refractive index layer is disposed so as to be in contact with an adhesive layer-side surface of the light guide plate and/or an adhesive layer-side surface of the optical member. The low-refractive index part and the low-refractive index layer each have a refractive index of 1.30 or less.
Description
本発明は、光学積層体に関する。
The present invention relates to an optical laminate.
導光板を用いて光を取り出す光学装置(例えば、画像表示装置、照明装置)において、導光板と周辺光学部材(例えば、反射板、拡散板、プリズムシート、光取り出しフィルム)とを積層する際に、低屈折率層またはパターン化した(すなわち、空気部を有する)接着層を介して積層する技術が知られている。このような技術によれば、低屈折率層または接着層の空気部を利用することにより、単純に粘着剤のみで積層する場合に比べて光の利用効率が高いと報告されている。しかし、このような技術によれば、導光板と周辺光学部材との積層体の一体物としての強度が不十分であるという問題がある。
When laminating a light guide plate and peripheral optical members (for example, a reflector, a diffuser plate, a prism sheet, a light extraction film) in an optical device (for example, an image display device, a lighting device) that extracts light using a light guide plate. , A technique of laminating via a low index of refraction layer or a patterned (ie, having an air portion) adhesive layer is known. According to such a technique, it is reported that by utilizing the air portion of the low refractive index layer or the adhesive layer, the light utilization efficiency is higher than that in the case of simply laminating with only the adhesive. However, according to such a technique, there is a problem that the strength of the laminated body of the light guide plate and the peripheral optical member as an integral body is insufficient.
本出願人は、このような問題を解決し得る光学積層体を開発している(特許文献1)。当該光学積層体は、導光板と該導光板に接着層を介して積層された光学部材とを有し、該接着層が平面視ドットパターンで形成されており、かつ、該ドットの密度が該導光板の入光側から導光方向に沿って大きくなるような勾配を有し、該導光板の導光方向に沿った両端部に低屈折率補強部が設けられている。上記所定のドットパターンを有する接着剤層と低屈折率補強部とを設けることにより、輝度が高く、輝度ムラが抑制され、かつ、一体物としての強度に優れた光学積層体を実現することができる。
The applicant has developed an optical laminate that can solve such a problem (Patent Document 1). The optical laminate has a light guide plate and an optical member laminated on the light guide plate via an adhesive layer, the adhesive layer is formed in a plan view dot pattern, and the density of the dots is the said. It has a gradient that increases from the light entrance side of the light guide plate along the light guide direction, and low refractive index reinforcing portions are provided at both ends of the light guide plate along the light guide direction. By providing the adhesive layer having the predetermined dot pattern and the low refractive index reinforcing portion, it is possible to realize an optical laminate having high luminance, suppression of luminance unevenness, and excellent strength as an integral body. can.
しかし、特許文献1の光学積層体は、高湿環境下において光漏れが生じる場合がある。
However, the optical laminate of Patent Document 1 may leak light in a high humidity environment.
本発明は上記従来の課題を解決するためになされたものであり、その主たる目的は、輝度が高く、輝度ムラが抑制され、一体物としての強度に優れ、かつ、高湿環境下における光漏れが抑制された光学積層体を提供することにある。
The present invention has been made to solve the above-mentioned conventional problems, and its main purpose is high brightness, suppression of uneven brightness, excellent strength as an integral body, and light leakage in a high humidity environment. It is an object of the present invention to provide an optical laminate in which the above is suppressed.
本発明の実施形態による光学積層体は、導光板と、該導光板に平面視ドットパターンで配置された接着層と、該導光板の導光方向に沿った両端部に配置された、低屈折率部を含む低屈折率補強部と、該導光板に該接着層および該低屈折率補強部を介して積層された光学部材と、を有する。該接着層は、ドットの密度が該導光板の入光側から導光方向に沿って大きくなるようなパターンを形成している。該導光板と該光学部材との間の該接着層および該低屈折率補強部が配置されていない領域においては、該導光板の接着層側の面および該光学部材の接着層側の面の少なくとも一方に接するようにして低屈折率層が配置されている。該低屈折率部および該低屈折率層の屈折率は1.30以下である。
1つの実施形態においては、上記低屈折率層は、上記導光板の接着層側の面および上記光学部材の接着層側の面の両方に接するようにして配置されている。1つの実施形態においては、上記低屈折率層は、上記導光板と上記光学部材との間の上記接着層および上記低屈折率補強部が配置されていない領域全域に充満している。
1つの実施形態においては、上記低屈折率部および上記低屈折率層の屈折率は1.25以下である。
1つの実施形態においては、上記低屈折率部および上記低屈折率層は、微細孔粒子同士が化学的に結合することにより形成された空隙層である。
1つの実施形態においては、上記低屈折率補強部は、基材と該基材に形成された低屈折率部と両面に最外層として設けられた粘着剤層とを有する。
1つの実施形態においては、上記低屈折率補強部の幅の合計は、上記導光板の幅の10%以下である。
1つの実施形態においては、上記低屈折率補強部の全光線透過率は85%以上である。
1つの実施形態においては、上記光学積層体は、上記導光板の入光側と反対側の端部に低屈折率補強部がさらに設けられている。 The optical laminate according to the embodiment of the present invention has a light guide plate, an adhesive layer arranged on the light guide plate in a plan view dot pattern, and low refractive index arranged at both ends of the light guide plate along the light guide direction. It has a low refractive index reinforcing portion including a rate portion, and an optical member laminated on the light guide plate via the adhesive layer and the low refractive index reinforcing portion. The adhesive layer forms a pattern in which the density of dots increases from the light entrance side of the light guide plate along the light guide direction. In the region where the adhesive layer and the low refractive index reinforcing portion between the light guide plate and the optical member are not arranged, the surface of the light guide plate on the adhesive layer side and the surface of the optical member on the adhesive layer side. The low refractive index layer is arranged so as to be in contact with at least one of them. The refractive index of the low refractive index portion and the low refractive index layer is 1.30 or less.
In one embodiment, the low refractive index layer is arranged so as to be in contact with both the surface of the light guide plate on the adhesive layer side and the surface of the optical member on the adhesive layer side. In one embodiment, the low refractive index layer fills the entire region where the adhesive layer and the low refractive index reinforcing portion between the light guide plate and the optical member are not arranged.
In one embodiment, the refractive index of the low refractive index portion and the low refractive index layer is 1.25 or less.
In one embodiment, the low refractive index portion and the low refractive index layer are void layers formed by chemically binding fine pore particles to each other.
In one embodiment, the low refractive index reinforcing portion has a base material, a low refractive index portion formed on the base material, and a pressure-sensitive adhesive layer provided on both sides as an outermost layer.
In one embodiment, the total width of the low refractive index reinforcing portions is 10% or less of the width of the light guide plate.
In one embodiment, the total light transmittance of the low refractive index reinforcing portion is 85% or more.
In one embodiment, the optical laminate is further provided with a low refractive index reinforcing portion at an end portion of the light guide plate on the side opposite to the light entering side.
1つの実施形態においては、上記低屈折率層は、上記導光板の接着層側の面および上記光学部材の接着層側の面の両方に接するようにして配置されている。1つの実施形態においては、上記低屈折率層は、上記導光板と上記光学部材との間の上記接着層および上記低屈折率補強部が配置されていない領域全域に充満している。
1つの実施形態においては、上記低屈折率部および上記低屈折率層の屈折率は1.25以下である。
1つの実施形態においては、上記低屈折率部および上記低屈折率層は、微細孔粒子同士が化学的に結合することにより形成された空隙層である。
1つの実施形態においては、上記低屈折率補強部は、基材と該基材に形成された低屈折率部と両面に最外層として設けられた粘着剤層とを有する。
1つの実施形態においては、上記低屈折率補強部の幅の合計は、上記導光板の幅の10%以下である。
1つの実施形態においては、上記低屈折率補強部の全光線透過率は85%以上である。
1つの実施形態においては、上記光学積層体は、上記導光板の入光側と反対側の端部に低屈折率補強部がさらに設けられている。 The optical laminate according to the embodiment of the present invention has a light guide plate, an adhesive layer arranged on the light guide plate in a plan view dot pattern, and low refractive index arranged at both ends of the light guide plate along the light guide direction. It has a low refractive index reinforcing portion including a rate portion, and an optical member laminated on the light guide plate via the adhesive layer and the low refractive index reinforcing portion. The adhesive layer forms a pattern in which the density of dots increases from the light entrance side of the light guide plate along the light guide direction. In the region where the adhesive layer and the low refractive index reinforcing portion between the light guide plate and the optical member are not arranged, the surface of the light guide plate on the adhesive layer side and the surface of the optical member on the adhesive layer side. The low refractive index layer is arranged so as to be in contact with at least one of them. The refractive index of the low refractive index portion and the low refractive index layer is 1.30 or less.
In one embodiment, the low refractive index layer is arranged so as to be in contact with both the surface of the light guide plate on the adhesive layer side and the surface of the optical member on the adhesive layer side. In one embodiment, the low refractive index layer fills the entire region where the adhesive layer and the low refractive index reinforcing portion between the light guide plate and the optical member are not arranged.
In one embodiment, the refractive index of the low refractive index portion and the low refractive index layer is 1.25 or less.
In one embodiment, the low refractive index portion and the low refractive index layer are void layers formed by chemically binding fine pore particles to each other.
In one embodiment, the low refractive index reinforcing portion has a base material, a low refractive index portion formed on the base material, and a pressure-sensitive adhesive layer provided on both sides as an outermost layer.
In one embodiment, the total width of the low refractive index reinforcing portions is 10% or less of the width of the light guide plate.
In one embodiment, the total light transmittance of the low refractive index reinforcing portion is 85% or more.
In one embodiment, the optical laminate is further provided with a low refractive index reinforcing portion at an end portion of the light guide plate on the side opposite to the light entering side.
本発明によれば、導光板と光学部材とを有し、該導光板の導光方向に沿ってドット密度の勾配を有する平面視ドットパターンの接着層を有する光学積層体において、該導光板の導光方向に沿った両端部に低屈折率部を含む低屈折率補強部を設け、ならびに、該導光板と該光学部材との間の該接着層および該低屈折率補強部が配置されていない領域において該導光板の接着層側の面および該光学部材の接着層側の面の少なくとも一方に接するようにして低屈折率層を設け、さらに、低屈折率部および低屈折率層の屈折率を1.30以下とすることにより、輝度が高く、輝度ムラが抑制され、一体物としての強度に優れ、かつ、高湿環境下における光漏れが抑制された光学積層体を実現することができる。
According to the present invention, in an optical laminate having a light guide plate and an optical member and having an adhesive layer of a plan view dot pattern having a gradient of dot density along the light guide direction of the light guide plate, the light guide plate is provided. A low refractive index reinforcing portion including a low refractive index portion is provided at both ends along the light guide direction, and the adhesive layer and the low refractive index reinforcing portion between the light guide plate and the optical member are arranged. A low refractive index layer is provided so as to be in contact with at least one of the surface of the light guide plate on the adhesive layer side and the surface of the optical member on the adhesive layer side, and the refraction of the low refractive index portion and the low refractive index layer is further provided. By setting the ratio to 1.30 or less, it is possible to realize an optical laminate having high brightness, suppression of uneven brightness, excellent strength as an integral body, and suppression of light leakage in a high humidity environment. can.
以下、本発明の実施形態について説明するが、本発明はこれらの実施形態には限定されない。
Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to these embodiments.
A.光学積層体の全体構成
図1Aは、本発明の1つの実施形態による光学積層体の概略断面図であり;図1Bは、本発明の別の実施形態による光学積層体の概略断面図であり;図1Cは、本発明のさらに別の実施形態による光学積層体の概略断面図であり;図2は、図1Aの光学積層体の光学部材を取り除いた状態を示す概略平面図である。図1Aの光学積層体100は、導光板10と、導光板10に平面視ドットパターンで配置された接着層20と、導光板10の導光方向に沿った両端部に配置された低屈折率補強部40と、導光板10に接着層20および低屈折率補強部40を介して積層された光学部材30と、を有する。接着層20は、図2に示すように、ドットの密度が導光板の入光側から導光方向(図面の左側から右に向かう方向)に沿って大きくなるようなパターンを形成している。このような密度勾配を有するドットパターンの接着層を設けることにより、光量が大きい導光板の入光側端部において空気による全反射を利用することができ、したがって、導光板内においてきわめて良好な光の伝播が実現される。その結果、輝度を高くすることができ、かつ、輝度ムラ(入光側に近い部分と入光側から遠い部分での明るさが異なること)を顕著に抑制することができる。一方で、このような接着層は、接着強度が不均一であり(具体的には、入光側の接着強度が小さく、入光側と反対側の接着強度が大きく)、その結果、光学積層体の一体物としての強度が不十分となる。これに対し、低屈折率補強部を設けることにより、光学積層体の一体物としての十分な強度を実現することができる。さらに、本発明の実施形態に用いられる低屈折率補強部は、以下のような利点を有する:(1)補強部自体の屈折率が低いので、光の利用効率を低下させることなく(結果として、輝度を高く維持し、かつ、輝度ムラを抑制して)光学積層体の一体物としての強度を確保することができる;(2)細長形状とすることができるので、光学積層体が適用される画像表示装置の表示領域に対する影響を最小限に抑えることができる。 A. Overall Configuration of Optical Laminates FIG. 1A is a schematic cross-sectional view of an optical laminate according to one embodiment of the invention; FIG. 1B is a schematic cross-sectional view of an optical laminate according to another embodiment of the invention; FIG. 1C is a schematic cross-sectional view of an optical laminate according to still another embodiment of the present invention; FIG. 2 is a schematic plan view showing a state in which the optical member of the optical laminate of FIG. 1A is removed. Theoptical laminate 100 of FIG. 1A has a light guide plate 10, an adhesive layer 20 arranged on the light guide plate 10 in a plan view dot pattern, and a low refractive index arranged at both ends of the light guide plate 10 along the light guide direction. It has a reinforcing portion 40 and an optical member 30 laminated on the light guide plate 10 via an adhesive layer 20 and a low refractive index reinforcing portion 40. As shown in FIG. 2, the adhesive layer 20 forms a pattern in which the density of dots increases from the light entrance side of the light guide plate along the light guide direction (direction from the left side to the right side of the drawing). By providing the adhesive layer of the dot pattern having such a density gradient, total reflection by air can be utilized at the light entrance side end of the light guide plate having a large amount of light, and therefore, extremely good light in the light guide plate. Propagation is realized. As a result, the brightness can be increased and uneven brightness (the brightness is different between the portion near the incoming light side and the portion far from the incoming light side) can be remarkably suppressed. On the other hand, such an adhesive layer has a non-uniform adhesive strength (specifically, the adhesive strength on the incoming light side is small and the adhesive strength on the opposite side to the incoming light side is large), and as a result, the optical lamination is performed. The strength as an integral part of the body becomes insufficient. On the other hand, by providing the low refractive index reinforcing portion, sufficient strength as an integral body of the optical laminate can be realized. Further, the low refractive index reinforcing portion used in the embodiment of the present invention has the following advantages: (1) Since the refractive index of the reinforcing portion itself is low, the efficiency of light utilization is not reduced (as a result). It is possible to secure the strength of the optical laminate as an integral body (while maintaining high brightness and suppressing uneven brightness); (2) Since it can be formed into an elongated shape, the optical laminate is applied. The effect on the display area of the image display device can be minimized.
図1Aは、本発明の1つの実施形態による光学積層体の概略断面図であり;図1Bは、本発明の別の実施形態による光学積層体の概略断面図であり;図1Cは、本発明のさらに別の実施形態による光学積層体の概略断面図であり;図2は、図1Aの光学積層体の光学部材を取り除いた状態を示す概略平面図である。図1Aの光学積層体100は、導光板10と、導光板10に平面視ドットパターンで配置された接着層20と、導光板10の導光方向に沿った両端部に配置された低屈折率補強部40と、導光板10に接着層20および低屈折率補強部40を介して積層された光学部材30と、を有する。接着層20は、図2に示すように、ドットの密度が導光板の入光側から導光方向(図面の左側から右に向かう方向)に沿って大きくなるようなパターンを形成している。このような密度勾配を有するドットパターンの接着層を設けることにより、光量が大きい導光板の入光側端部において空気による全反射を利用することができ、したがって、導光板内においてきわめて良好な光の伝播が実現される。その結果、輝度を高くすることができ、かつ、輝度ムラ(入光側に近い部分と入光側から遠い部分での明るさが異なること)を顕著に抑制することができる。一方で、このような接着層は、接着強度が不均一であり(具体的には、入光側の接着強度が小さく、入光側と反対側の接着強度が大きく)、その結果、光学積層体の一体物としての強度が不十分となる。これに対し、低屈折率補強部を設けることにより、光学積層体の一体物としての十分な強度を実現することができる。さらに、本発明の実施形態に用いられる低屈折率補強部は、以下のような利点を有する:(1)補強部自体の屈折率が低いので、光の利用効率を低下させることなく(結果として、輝度を高く維持し、かつ、輝度ムラを抑制して)光学積層体の一体物としての強度を確保することができる;(2)細長形状とすることができるので、光学積層体が適用される画像表示装置の表示領域に対する影響を最小限に抑えることができる。 A. Overall Configuration of Optical Laminates FIG. 1A is a schematic cross-sectional view of an optical laminate according to one embodiment of the invention; FIG. 1B is a schematic cross-sectional view of an optical laminate according to another embodiment of the invention; FIG. 1C is a schematic cross-sectional view of an optical laminate according to still another embodiment of the present invention; FIG. 2 is a schematic plan view showing a state in which the optical member of the optical laminate of FIG. 1A is removed. The
本発明の実施形態においては、導光板10と光学部材30との間の接着層20および低屈折率補強部40が配置されていない領域(すなわち、光学積層体における空隙部)に、導光板10の接着層20側の面および光学部材30の接着層20側の面の少なくとも一方に接するようにして低屈折率層50が配置されている。1つの実施形態においては、低屈折率層50は、導光板10の接着層20側の面および光学部材30の接着層20側の面の両方に接するようにして配置されている。図1Aに示す例においては、低屈折率層50は、導光板10と光学部材30との間の接着層20および低屈折率補強部40が配置されていない領域全域(すなわち、光学積層体における空隙部全域)に充満している。このような低屈折率層を設けることにより、高湿環境下における光漏れを抑制することができる。より詳細には以下のとおりである。本出願人は、導光板と、ドットの密度が導光板の入光側から導光方向に沿って大きくなるようなパターンで導光板に配置された接着層と、導光板の導光方向に沿った両端部に配置された低屈折率補強部と、導光板に接着層および低屈折率補強部を介して積層された光学部材と、を有する光学積層体を開発した。このような光学積層体は、輝度が高く、輝度ムラが抑制され、かつ、一体物としての強度に優れたものである。一方で、本発明者らは、このような光学積層体においては、高湿環境下において光漏れが生じる場合があるという新たな課題を発見し、当該光漏れは高湿環境下において導光板と光学部材との間の接着層および低屈折率補強部が配置されていない領域(空隙部)に生じる結露に起因することを見出した。さらに、本発明者らは結露と光漏れとの関係について鋭意検討した結果、空隙部に低屈折率層を設けることにより、本出願人による上記光学積層体の優れた特性を維持しつつ、結露発生による光漏れを抑制できることを見出し、本発明を完成するに至った。すなわち、図1A~図1Cのように空隙部に低屈折率層を配置することにより、結露が発生したとしても光学部材30の接着層20側の面と反対側の面からの光漏れを抑制することができる。さらに、図1Aのように低屈折率層が空隙部に充満することにより、空隙部が実質的になくなるので、結露を顕著に抑制し、結果として光漏れを顕著に抑制することができる。加えて、空隙部に低屈折率層を配置することにより、空隙部(空気部、屈折率1.00)との屈折率の差を小さくすることができる。その結果、光の利用効率を実質的に低下させることがないので、輝度を高く維持し、かつ、輝度ムラを抑制するという上記光学積層体の優れた特性を維持することができる。また、以下の利点も得られ得る。光学積層体が押圧された場合、空隙部が存在すると導光板と光学部材が接触し、当該接触に起因した光漏れが生じる場合がある。空隙部に低屈折率層を配置することにより、当該接触を回避することができるので、このようなメカニズムによる光漏れも抑制することができる。
In the embodiment of the present invention, the light guide plate 10 is located in a region (that is, a gap portion in the optical laminate) in which the adhesive layer 20 and the low refractive index reinforcing portion 40 are not arranged between the light guide plate 10 and the optical member 30. The low refractive index layer 50 is arranged so as to be in contact with at least one of the surface on the adhesive layer 20 side and the surface on the adhesive layer 20 side of the optical member 30. In one embodiment, the low refractive index layer 50 is arranged so as to be in contact with both the surface of the light guide plate 10 on the adhesive layer 20 side and the surface of the optical member 30 on the adhesive layer 20 side. In the example shown in FIG. 1A, the low refractive index layer 50 is the entire region (that is, in the optical laminate) in which the adhesive layer 20 between the light guide plate 10 and the optical member 30 and the low refractive index reinforcing portion 40 are not arranged. It fills the entire gap). By providing such a low refractive index layer, light leakage in a high humidity environment can be suppressed. More details are as follows. Applicants have a light guide plate, an adhesive layer arranged on the light guide plate in a pattern such that the dot density increases from the light entrance side of the light guide plate along the light guide direction, and along the light guide direction of the light guide plate. We have developed an optical laminate having low refractive index reinforcing portions arranged at both ends and an optical member laminated on a light guide plate via an adhesive layer and a low refractive index reinforcing portion. Such an optical laminate has high luminance, suppresses luminance unevenness, and has excellent strength as an integral body. On the other hand, the present inventors have discovered a new problem that light leakage may occur in such an optical laminate in a high humidity environment, and the light leakage is a light guide plate in a high humidity environment. It has been found that this is caused by dew condensation that occurs in the region (void portion) where the adhesive layer and the low refractive index reinforcing portion between the optical member and the optical member are not arranged. Furthermore, as a result of diligent studies on the relationship between dew condensation and light leakage, the present inventors have provided a low refractive index layer in the void portion, so that dew condensation is maintained while maintaining the excellent characteristics of the optical laminate by the present applicant. We have found that light leakage due to generation can be suppressed, and have completed the present invention. That is, by arranging the low refractive index layer in the void portion as shown in FIGS. 1A to 1C, even if dew condensation occurs, light leakage from the surface of the optical member 30 opposite to the surface on the adhesive layer 20 side is suppressed. can do. Further, as shown in FIG. 1A, when the low refractive index layer fills the void portion, the void portion is substantially eliminated, so that dew condensation can be remarkably suppressed, and as a result, light leakage can be remarkably suppressed. In addition, by arranging the low refractive index layer in the void portion, the difference in the refractive index from the void portion (air portion, refractive index 1.00) can be reduced. As a result, since the light utilization efficiency is not substantially lowered, it is possible to maintain the excellent characteristics of the optical laminate, that is, the brightness is maintained high and the brightness unevenness is suppressed. In addition, the following advantages can also be obtained. When the optical laminate is pressed, the presence of a gap may cause the light guide plate and the optical member to come into contact with each other, resulting in light leakage due to the contact. By arranging the low refractive index layer in the void portion, the contact can be avoided, so that light leakage due to such a mechanism can be suppressed.
低屈折率層50は、導光板の接着層側の面および光学部材の接着層側の面の両方に接するようにして配置されてもよく、図1Aに示すように空隙部に充満してもよく、図1Bに示すように光学部材30の接着層20側の面のみに接するようにして配置されてもよく、図1Cに示すように導光板10の接着層20側の面のみに接するようにして配置されてもよい。いずれの構成においても、結露および/または導光板と光学部材との接触を抑制し、結果として光漏れを抑制することができる。好ましくは、図1Aの構成である。結露自体を抑制する効果(結果として、光漏れ抑制効果)を有するからである。
The low refractive index layer 50 may be arranged so as to be in contact with both the surface of the light guide plate on the adhesive layer side and the surface of the optical member on the adhesive layer side, or may fill the void portion as shown in FIG. 1A. It may be arranged so as to be in contact with only the surface of the optical member 30 on the adhesive layer 20 side as shown in FIG. 1B, and may be arranged so as to be in contact with only the surface of the light guide plate 10 on the adhesive layer 20 side as shown in FIG. 1C. It may be arranged in. In either configuration, dew condensation and / or contact between the light guide plate and the optical member can be suppressed, and as a result, light leakage can be suppressed. Preferably, it is the configuration of FIG. 1A. This is because it has an effect of suppressing dew condensation itself (as a result, a light leakage suppressing effect).
空隙部または接着層20の厚みに対する低屈折率層50の厚みの比率は、光漏れを抑制できる限り特に限定されない。
The ratio of the thickness of the low refractive index layer 50 to the thickness of the void portion or the adhesive layer 20 is not particularly limited as long as light leakage can be suppressed.
以下、光学積層体の構成要素について具体的に説明する。
Hereinafter, the components of the optical laminate will be specifically described.
B.導光板
導光板10は、代表的には、樹脂(好ましくは、透明樹脂)のフィルムまたは板状物、あるいはガラスで構成され得る。このような樹脂の代表例としては、熱可塑性樹脂、反応性樹脂(例えば、電離放射線硬化性樹脂)が挙げられる。熱可塑性樹脂の具体例としては、ポリメタクリル酸メチル(PMMA)、ポリアクリロニトリル等の(メタ)アクリル系樹脂、ポリカーボネート(PC)樹脂、PET等のポリエステル樹脂、トリアセチルセルロース(TAC)等のセルロース系樹脂、環状ポリオレフィン系樹脂、スチレン系樹脂が挙げられる。電離放射線硬化性樹脂の具体例としては、エポキシアクリレート系樹脂、ウレタンアクリレート系樹脂が挙げられる。これらの樹脂は、単独で用いてもよく2種以上を併用してもよい。 B. Light guide plate Thelight guide plate 10 may be typically made of a resin (preferably transparent resin) film or plate-like material, or glass. Typical examples of such resins include thermoplastic resins and reactive resins (for example, ionizing radiation curable resins). Specific examples of the thermoplastic resin include (meth) acrylic resins such as polymethyl methacrylate (PMMA) and polyacrylonitrile, polyester resins such as polycarbonate (PC) resin and PET, and cellulose-based resins such as triacetyl cellulose (TAC). Examples thereof include resins, cyclic polyolefin resins, and styrene resins. Specific examples of the ionizing radiation curable resin include epoxy acrylate-based resin and urethane acrylate-based resin. These resins may be used alone or in combination of two or more.
導光板10は、代表的には、樹脂(好ましくは、透明樹脂)のフィルムまたは板状物、あるいはガラスで構成され得る。このような樹脂の代表例としては、熱可塑性樹脂、反応性樹脂(例えば、電離放射線硬化性樹脂)が挙げられる。熱可塑性樹脂の具体例としては、ポリメタクリル酸メチル(PMMA)、ポリアクリロニトリル等の(メタ)アクリル系樹脂、ポリカーボネート(PC)樹脂、PET等のポリエステル樹脂、トリアセチルセルロース(TAC)等のセルロース系樹脂、環状ポリオレフィン系樹脂、スチレン系樹脂が挙げられる。電離放射線硬化性樹脂の具体例としては、エポキシアクリレート系樹脂、ウレタンアクリレート系樹脂が挙げられる。これらの樹脂は、単独で用いてもよく2種以上を併用してもよい。 B. Light guide plate The
導光板の厚みは、例えば100μm~100mmであり得る。導光板の厚みは、好ましくは50mm以下であり、より好ましくは30mm以下であり、さらに好ましくは10mm以下である。
The thickness of the light guide plate can be, for example, 100 μm to 100 mm. The thickness of the light guide plate is preferably 50 mm or less, more preferably 30 mm or less, and further preferably 10 mm or less.
導光板の屈折率は、好ましくは1.47以上であり、より好ましくは1.47~1.60であり、さらに好ましくは1.47~1.55である。導光板の屈折率と低屈折率補強部の低屈折率層の屈折率との差は、好ましくは0.22以上であり、より好ましくは0.22~0.40であり、さらに好ましくは0.25~0.35である。導光板の屈折率は、導光板の構成材料を適切に選択することにより調整され得る。
The refractive index of the light guide plate is preferably 1.47 or more, more preferably 1.47 to 1.60, and further preferably 1.47 to 1.55. The difference between the refractive index of the light guide plate and the refractive index of the low refractive index layer of the low refractive index reinforcing portion is preferably 0.22 or more, more preferably 0.22 to 0.40, and further preferably 0. It is .25 to 0.35. The refractive index of the light guide plate can be adjusted by appropriately selecting the constituent material of the light guide plate.
C.接着層
接着層20は、上記のとおり、平面視ドットパターンで形成されており、かつ、ドットの密度は導光板の入光側から導光方向に沿って大きくなるような勾配を有する。このような構成であれば、光量が大きい導光板の入光側端部において空気による全反射を利用することができ、したがって、導光板内においてきわめて良好な光の伝播が実現される。その結果、輝度を高くすることができ、かつ、輝度ムラ(入光側に近い部分と入光側から遠い部分での明るさが異なること)を顕著に抑制することができる。ドット密度の勾配は、図2に示すように導光方向に沿って連続的に変化してもよく、導光方向に沿った所定領域ごとに段階的に変化してもよい。例えば、入光側の端から導光板の長さ方向の10%までの領域のドット密度(平均)は、好ましくは0%~50%であり、入光側と反対側の端から導光板の長さ方向の10%までの領域のドット密度(平均)は、好ましくは50%~100%である。 C. Adhesive layer As described above, theadhesive layer 20 is formed of a dot pattern in a plan view, and has a gradient such that the density of dots increases from the light entrance side of the light guide plate along the light guide direction. With such a configuration, total reflection by air can be utilized at the light entrance side end portion of the light guide plate having a large amount of light, and therefore, extremely good light propagation is realized in the light guide plate. As a result, the brightness can be increased and uneven brightness (the brightness is different between the portion near the incoming light side and the portion far from the incoming light side) can be remarkably suppressed. The gradient of the dot density may change continuously along the light guide direction as shown in FIG. 2, or may change stepwise for each predetermined region along the light guide direction. For example, the dot density (average) in the region from the end on the light entering side to 10% in the length direction of the light guide plate is preferably 0% to 50%, and the light guide plate is from the end opposite to the light entrance side. The dot density (average) of the region up to 10% in the length direction is preferably 50% to 100%.
接着層20は、上記のとおり、平面視ドットパターンで形成されており、かつ、ドットの密度は導光板の入光側から導光方向に沿って大きくなるような勾配を有する。このような構成であれば、光量が大きい導光板の入光側端部において空気による全反射を利用することができ、したがって、導光板内においてきわめて良好な光の伝播が実現される。その結果、輝度を高くすることができ、かつ、輝度ムラ(入光側に近い部分と入光側から遠い部分での明るさが異なること)を顕著に抑制することができる。ドット密度の勾配は、図2に示すように導光方向に沿って連続的に変化してもよく、導光方向に沿った所定領域ごとに段階的に変化してもよい。例えば、入光側の端から導光板の長さ方向の10%までの領域のドット密度(平均)は、好ましくは0%~50%であり、入光側と反対側の端から導光板の長さ方向の10%までの領域のドット密度(平均)は、好ましくは50%~100%である。 C. Adhesive layer As described above, the
接着層は、接着剤で構成されてもよく、粘着剤で構成されてもよい。好ましくは、接着層は接着剤で構成される。パターン形成が容易だからである。接着剤を用いることにより、インクジェット、印刷等によるパターン形成を行うことができる。接着剤としては、任意の適切な接着剤を用いることができる。好ましくは、活性エネルギー線(例えば、紫外線、可視光)硬化型接着剤である。活性エネルギー線硬化型接着剤の具体例としては、アクリル系接着剤、エポキシ系接着剤、ビニル系接着剤、チオール系接着剤、ウレタン系接着剤、シリコーン系接着剤が挙げられる。活性エネルギー線硬化型接着剤と熱硬化型接着剤とを組み合わせて用いてもよい。粘着剤としては、例えば、高弾性率の粘着剤が挙げられる。
The adhesive layer may be composed of an adhesive or an adhesive. Preferably, the adhesive layer is composed of an adhesive. This is because pattern formation is easy. By using an adhesive, pattern formation can be performed by inkjet, printing, or the like. As the adhesive, any suitable adhesive can be used. Preferably, it is an active energy ray (for example, ultraviolet light, visible light) curable adhesive. Specific examples of the active energy ray-curable adhesive include acrylic adhesives, epoxy adhesives, vinyl adhesives, thiol adhesives, urethane adhesives, and silicone adhesives. The active energy ray-curable adhesive and the thermosetting adhesive may be used in combination. Examples of the pressure-sensitive adhesive include a pressure-sensitive adhesive having a high elastic modulus.
接着層の厚みは、例えば50μm以上、60μm以上、70μm以上、80μm以上、90μm以上、または100μm以上であって、1000μm以下、900μm以下、800μm以下、700μm以下、600μm以下または500μm以下であり得る。
The thickness of the adhesive layer may be, for example, 50 μm or more, 60 μm or more, 70 μm or more, 80 μm or more, 90 μm or more, or 100 μm or more, and may be 1000 μm or less, 900 μm or less, 800 μm or less, 700 μm or less, 600 μm or less, or 500 μm or less.
D.光学部材
光学部材30としては、導光板と積層され得る任意の適切な光学部材が挙げられる。光学部材の具体例としては、反射板、拡散板、プリズムシート、偏光板、位相差フィルム、導電性フィルム、基板、画像表示セルまたは画像表示パネルが挙げられる。 D. Optical member Examples of theoptical member 30 include any suitable optical member that can be laminated with the light guide plate. Specific examples of the optical member include a reflector, a diffuser, a prism sheet, a polarizing plate, a retardation film, a conductive film, a substrate, an image display cell, or an image display panel.
光学部材30としては、導光板と積層され得る任意の適切な光学部材が挙げられる。光学部材の具体例としては、反射板、拡散板、プリズムシート、偏光板、位相差フィルム、導電性フィルム、基板、画像表示セルまたは画像表示パネルが挙げられる。 D. Optical member Examples of the
E.低屈折率補強部
E-1.低屈折率補強部の配置および全体構成
低屈折率補強部40は、上記のとおり、導光板の導光方向に沿った両端部に設けられている。低屈折率補強部40の平面視形状としては、任意の適切な形状が採用され得る。具体的には、低屈折率補強部は、図2に示すように導光板の導光方向に沿って連続的に形成されてもよく、断続的に形成されてもよい。低屈折率補強部が連続的に形成される場合、低屈折率補強部は、例えば、図2に示すような細長矩形状であってもよく、テーパー状であってもよく、台形状であってもよい。低屈折率補強部がテーパー状である場合、低屈折率補強部は、入光側に向かって細くなる形状であってもよく、入光側と反対側に向かって細くなる形状であってもよい。低屈折率補強部が断続的に形成される場合、低屈折率補強部は、例えば、矩形状であってもよく、ドット状であってもよく、その他の任意の形状(例えば、三角形、正方形、多角形、半円形)であってもよい。低屈折率補強部の長さ(すなわち、導光方向に沿った長さ)は、それぞれ、導光板の導光方向の全長に対して、好ましくは50%以上であり、より好ましくは60%以上であり、さらに好ましくは70%以上であり、特に好ましくは80%以上である。低屈折率補強部の長さの上限は、導光板の導光方向の全長に対して100%である。すなわち、低屈折率補強部は、導光板の導光方向の全体にわたって設けられ得る。長さがこのような範囲であれば、十分な補強効果(すなわち、光学積層体の一体物としての強度)を実現することができる。なお、低屈折率補強部が断続的に形成される場合、低屈折率補強部の長さはそれぞれの長さの合計である。また、低屈折率補強部の長さは、それぞれが同一であってもよく異なっていてもよい。低屈折率補強部の幅(すなわち、導光方向と直交する方向に沿った長さ)は、それぞれ、導光板の幅に対して好ましくは5%以下である。低屈折率補強部の幅の合計は、導光板の幅に対して好ましくは10%以下であり、より好ましくは9%以下である。一方、低屈折率補強部の幅の合計は、例えば1%以上であり得る。幅がこのような範囲であれば、光学積層体が適用される画像表示装置の表示領域に悪影響を与えることなく、光学積層体の一体物としての強度を確保することができる。低屈折率補強部の全光線透過率は、好ましくは85%以上であり、より好ましくは90%以上である。全光線透過率がこのような範囲であれば、光学積層体が適用される画像表示装置の表示領域に悪影響を与えることなく、光学積層体の一体物としての強度を確保することができる。 E. Low refractive index reinforcement part E-1. Arrangement and overall configuration of the low refractive index reinforcing portion The low refractiveindex reinforcing portion 40 is provided at both ends of the light guide plate along the light guide direction as described above. Any suitable shape can be adopted as the plan view shape of the low refractive index reinforcing portion 40. Specifically, the low refractive index reinforcing portion may be formed continuously or intermittently along the light guide direction of the light guide plate as shown in FIG. When the low refractive index reinforcing portion is continuously formed, the low refractive index reinforcing portion may be, for example, an elongated rectangular shape as shown in FIG. 2, a tapered shape, or a trapezoidal shape. May be. When the low refractive index reinforcing portion has a tapered shape, the low refractive index reinforcing portion may have a shape that narrows toward the incoming light side or a shape that narrows toward the opposite side to the incoming light side. good. When the low index of refraction reinforcement is intermittently formed, the low index of refraction reinforcement may be, for example, rectangular, dot, or any other shape (eg, triangle, square). , Polygon, semi-circular). The length of the low refractive index reinforcing portion (that is, the length along the light guide direction) is preferably 50% or more, more preferably 60% or more, respectively, with respect to the total length of the light guide plate in the light guide direction. It is more preferably 70% or more, and particularly preferably 80% or more. The upper limit of the length of the low refractive index reinforcing portion is 100% with respect to the total length of the light guide plate in the light guide direction. That is, the low refractive index reinforcing portion may be provided over the entire light guide direction of the light guide plate. If the length is within such a range, a sufficient reinforcing effect (that is, the strength of the optical laminate as an integral body) can be realized. When the low refractive index reinforcing portion is intermittently formed, the length of the low refractive index reinforcing portion is the sum of the respective lengths. Further, the lengths of the low refractive index reinforcing portions may be the same or different. The width of the low refractive index reinforcing portion (that is, the length along the direction orthogonal to the light guide direction) is preferably 5% or less with respect to the width of the light guide plate, respectively. The total width of the low refractive index reinforcing portions is preferably 10% or less, more preferably 9% or less with respect to the width of the light guide plate. On the other hand, the total width of the low refractive index reinforcing portions may be, for example, 1% or more. When the width is within such a range, the strength of the optical laminate as an integral body can be ensured without adversely affecting the display area of the image display device to which the optical laminate is applied. The total light transmittance of the low refractive index reinforcing portion is preferably 85% or more, more preferably 90% or more. When the total light transmittance is within such a range, the strength of the optical laminate as an integral body can be ensured without adversely affecting the display area of the image display device to which the optical laminate is applied.
E-1.低屈折率補強部の配置および全体構成
低屈折率補強部40は、上記のとおり、導光板の導光方向に沿った両端部に設けられている。低屈折率補強部40の平面視形状としては、任意の適切な形状が採用され得る。具体的には、低屈折率補強部は、図2に示すように導光板の導光方向に沿って連続的に形成されてもよく、断続的に形成されてもよい。低屈折率補強部が連続的に形成される場合、低屈折率補強部は、例えば、図2に示すような細長矩形状であってもよく、テーパー状であってもよく、台形状であってもよい。低屈折率補強部がテーパー状である場合、低屈折率補強部は、入光側に向かって細くなる形状であってもよく、入光側と反対側に向かって細くなる形状であってもよい。低屈折率補強部が断続的に形成される場合、低屈折率補強部は、例えば、矩形状であってもよく、ドット状であってもよく、その他の任意の形状(例えば、三角形、正方形、多角形、半円形)であってもよい。低屈折率補強部の長さ(すなわち、導光方向に沿った長さ)は、それぞれ、導光板の導光方向の全長に対して、好ましくは50%以上であり、より好ましくは60%以上であり、さらに好ましくは70%以上であり、特に好ましくは80%以上である。低屈折率補強部の長さの上限は、導光板の導光方向の全長に対して100%である。すなわち、低屈折率補強部は、導光板の導光方向の全体にわたって設けられ得る。長さがこのような範囲であれば、十分な補強効果(すなわち、光学積層体の一体物としての強度)を実現することができる。なお、低屈折率補強部が断続的に形成される場合、低屈折率補強部の長さはそれぞれの長さの合計である。また、低屈折率補強部の長さは、それぞれが同一であってもよく異なっていてもよい。低屈折率補強部の幅(すなわち、導光方向と直交する方向に沿った長さ)は、それぞれ、導光板の幅に対して好ましくは5%以下である。低屈折率補強部の幅の合計は、導光板の幅に対して好ましくは10%以下であり、より好ましくは9%以下である。一方、低屈折率補強部の幅の合計は、例えば1%以上であり得る。幅がこのような範囲であれば、光学積層体が適用される画像表示装置の表示領域に悪影響を与えることなく、光学積層体の一体物としての強度を確保することができる。低屈折率補強部の全光線透過率は、好ましくは85%以上であり、より好ましくは90%以上である。全光線透過率がこのような範囲であれば、光学積層体が適用される画像表示装置の表示領域に悪影響を与えることなく、光学積層体の一体物としての強度を確保することができる。 E. Low refractive index reinforcement part E-1. Arrangement and overall configuration of the low refractive index reinforcing portion The low refractive
低屈折率補強部は、導光板の導光方向に沿った両端に設けられてもよく、両端から一定距離離間した内側に設けられてもよい。好ましくは、低屈折率補強部は、導光板の導光方向に沿った両端またはその近傍に設けられる。このような構成であれば、表示エリアへの影響を最小限とすることができる。
The low refractive index reinforcing portions may be provided at both ends of the light guide plate along the light guide direction, or may be provided inside at a certain distance from both ends. Preferably, the low refractive index reinforcing portion is provided at both ends or in the vicinity thereof along the light guide direction of the light guide plate. With such a configuration, the influence on the display area can be minimized.
低屈折率補強部が連続的に形成される場合、低屈折率補強部は、導光板の導光方向の中心部に設けられてもよく、偏った位置(例えば、入光側、入光側と反対側)に設けられてもよい。低屈折率補強部が断続的に形成される場合、それぞれの配置密度は、導光方向全体にわたって均一であってもよく、導光方向に沿って変化してもよい。
When the low refractive index reinforcing portion is continuously formed, the low refractive index reinforcing portion may be provided at the center of the light guide plate in the light guide direction, and the low refractive index reinforcing portion may be provided at a biased position (for example, the incoming light side, the incoming light side). It may be provided on the opposite side). When the low refractive index reinforcing portions are formed intermittently, the respective arrangement densities may be uniform over the entire light guide direction or may change along the light guide direction.
低屈折率補強部は、上記のとおり、導光板の導光方向に沿った両端部に設けられていればよい。したがって、低屈折率補強部は、上記の位置以外の任意の適切な位置に設けられてもよい。1つの実施形態においては、低屈折率補強部は、導光板の入光側と反対側の端部にさらに設けられてもよい。このような構成であれば、さらなる補強効果が得られ得る。
As described above, the low refractive index reinforcing portions may be provided at both ends of the light guide plate along the light guide direction. Therefore, the low refractive index reinforcing portion may be provided at any appropriate position other than the above-mentioned position. In one embodiment, the low refractive index reinforcing portion may be further provided at the end portion of the light guide plate on the side opposite to the light entering side. With such a configuration, a further reinforcing effect can be obtained.
図3は、低屈折率補強部の一例を示す概略断面図である。低屈折率補強部40は、基材41と、基材41に形成された低屈折率部42と、両面に最外層として設けられた粘着剤層43、44と、を有する。すなわち、低屈折率補強部は両面テープとして構成され、両面の粘着剤層により導光板と光学部材とを貼り合わせる。なお、図面から明らかなとおり、低屈折率部42は実質的には低屈折率層であるが、本明細書においては低屈折率層50との区別を容易にするために低屈折率部と称する。
FIG. 3 is a schematic cross-sectional view showing an example of a low refractive index reinforcing portion. The low refractive index reinforcing portion 40 has a base material 41, a low refractive index portion 42 formed on the base material 41, and adhesive layers 43 and 44 provided as outermost layers on both sides. That is, the low refractive index reinforcing portion is configured as a double-sided tape, and the light guide plate and the optical member are bonded to each other by the adhesive layers on both sides. As is clear from the drawings, the low refractive index section 42 is substantially a low refractive index layer, but in the present specification, it is referred to as a low refractive index section in order to easily distinguish it from the low refractive index layer 50. Refer to.
E-2.基材
基材41は、代表的には、樹脂(好ましくは、透明樹脂)のフィルムまたは板状物で構成され得る。このような樹脂の代表例としては、熱可塑性樹脂、反応性樹脂(例えば、電離放射線硬化性樹脂)が挙げられる。熱可塑性樹脂の具体例としては、ポリメタクリル酸メチル(PMMA)、ポリアクリロニトリル等の(メタ)アクリル系樹脂、ポリカーボネート(PC)樹脂、PET等のポリエステル樹脂、トリアセチルセルロース(TAC)等のセルロース系樹脂、環状ポリオレフィン系樹脂、スチレン系樹脂が挙げられる。電離放射線硬化性樹脂の具体例としては、エポキシアクリレート系樹脂、ウレタンアクリレート系樹脂が挙げられる。これらの樹脂は、単独で用いてもよく2種以上を併用してもよい。 E-2. Base material Thebase material 41 can be typically composed of a film or a plate-like material of a resin (preferably a transparent resin). Typical examples of such resins include thermoplastic resins and reactive resins (for example, ionizing radiation curable resins). Specific examples of the thermoplastic resin include (meth) acrylic resins such as polymethyl methacrylate (PMMA) and polyacrylonitrile, polyester resins such as polycarbonate (PC) resin and PET, and cellulose-based resins such as triacetyl cellulose (TAC). Examples thereof include resins, cyclic polyolefin resins, and styrene resins. Specific examples of the ionizing radiation curable resin include epoxy acrylate-based resin and urethane acrylate-based resin. These resins may be used alone or in combination of two or more.
基材41は、代表的には、樹脂(好ましくは、透明樹脂)のフィルムまたは板状物で構成され得る。このような樹脂の代表例としては、熱可塑性樹脂、反応性樹脂(例えば、電離放射線硬化性樹脂)が挙げられる。熱可塑性樹脂の具体例としては、ポリメタクリル酸メチル(PMMA)、ポリアクリロニトリル等の(メタ)アクリル系樹脂、ポリカーボネート(PC)樹脂、PET等のポリエステル樹脂、トリアセチルセルロース(TAC)等のセルロース系樹脂、環状ポリオレフィン系樹脂、スチレン系樹脂が挙げられる。電離放射線硬化性樹脂の具体例としては、エポキシアクリレート系樹脂、ウレタンアクリレート系樹脂が挙げられる。これらの樹脂は、単独で用いてもよく2種以上を併用してもよい。 E-2. Base material The
基材の厚みは、例えば10μm~100μmであり、好ましくは10μm~50μmである。
The thickness of the base material is, for example, 10 μm to 100 μm, preferably 10 μm to 50 μm.
基材の屈折率は、好ましくは1.47以上であり、より好ましくは1.47~1.60であり、さらに好ましくは1.47~1.55である。このような範囲であれば、導光板から取り出される光に悪影響を与えることなく画像表示セルに導くことができる。
The refractive index of the base material is preferably 1.47 or more, more preferably 1.47 to 1.60, and further preferably 1.47 to 1.55. Within such a range, the light can be guided to the image display cell without adversely affecting the light extracted from the light guide plate.
E-3.低屈折率部
低屈折率部は、代表的には、内部に空隙を有する。低屈折率部の空隙率は、代表的には50体積%以上であり、好ましくは70体積%以上であり、より好ましくは80体積%以上である。一方、空隙率は、例えば90体積%以下であり、好ましくは85体積%以下である。空隙率が上記範囲内であることにより、低屈折率部の屈折率を適切な範囲とすることができる。空隙率は、エリプソメーターで測定した屈折率の値から、Lorentz‐Lorenz’s formula(ローレンツ-ローレンツの式)より空隙率を算出された値である。 E-3. Low refractive index portion The low refractive index portion typically has a void inside. The porosity of the low refractive index portion is typically 50% by volume or more, preferably 70% by volume or more, and more preferably 80% by volume or more. On the other hand, the porosity is, for example, 90% by volume or less, preferably 85% by volume or less. When the porosity is within the above range, the refractive index of the low refractive index portion can be set within an appropriate range. The porosity is a value obtained by calculating the porosity from the value of the refractive index measured by the ellipsometer from the Lorentz-Lorenz's formula (Lorentz-Lorenz's formula).
低屈折率部は、代表的には、内部に空隙を有する。低屈折率部の空隙率は、代表的には50体積%以上であり、好ましくは70体積%以上であり、より好ましくは80体積%以上である。一方、空隙率は、例えば90体積%以下であり、好ましくは85体積%以下である。空隙率が上記範囲内であることにより、低屈折率部の屈折率を適切な範囲とすることができる。空隙率は、エリプソメーターで測定した屈折率の値から、Lorentz‐Lorenz’s formula(ローレンツ-ローレンツの式)より空隙率を算出された値である。 E-3. Low refractive index portion The low refractive index portion typically has a void inside. The porosity of the low refractive index portion is typically 50% by volume or more, preferably 70% by volume or more, and more preferably 80% by volume or more. On the other hand, the porosity is, for example, 90% by volume or less, preferably 85% by volume or less. When the porosity is within the above range, the refractive index of the low refractive index portion can be set within an appropriate range. The porosity is a value obtained by calculating the porosity from the value of the refractive index measured by the ellipsometer from the Lorentz-Lorenz's formula (Lorentz-Lorenz's formula).
低屈折率部の屈折率は、好ましくは1.25以下であり、より好ましくは1.20以下であり、さらに好ましくは1.15以下である。屈折率の下限は、例えば1.01であり得る。このような範囲であれば、低屈折率補強部を介して得られる導光板と光学部材との積層構造において非常に優れた光の利用効率を実現することができる。屈折率は、特に断らない限り、波長550nmにおいて測定した屈折率をいう。屈折率は、以下の実施例の「(I)低屈折率層および低屈折率補強部の低屈折率部の屈折率」に記載の方法によって測定された値である。
The refractive index of the low refractive index portion is preferably 1.25 or less, more preferably 1.20 or less, and further preferably 1.15 or less. The lower limit of the refractive index can be, for example, 1.01. Within such a range, it is possible to realize extremely excellent light utilization efficiency in the laminated structure of the light guide plate and the optical member obtained through the low refractive index reinforcing portion. Refractive index refers to the refractive index measured at a wavelength of 550 nm unless otherwise specified. The refractive index is a value measured by the method described in "(I) Refractive index of the low refractive index portion of the low refractive index layer and the low refractive index reinforcing portion" of the following Example.
低屈折率部は、上記所望の空隙率および屈折率を有する限りにおいて、任意の適切な構成が採用され得る。低屈折率部は、好ましくは塗工または印刷等により形成され得る。低屈折率部を構成する材料としては、例えば、国際公開第2004/113966号、特開2013-254183号公報、および特開2012-189802号公報に記載の材料を採用し得る。具体的には、例えば、シリカ系化合物;加水分解性シラン類および/またはシルセスキオキサン、ならびにその部分加水分解物および脱水縮合物;有機ポリマー;シラノール基を含有するケイ素化合物;ケイ酸塩を酸やイオン交換樹脂に接触させることにより得られる活性シリカ;重合性モノマー(例えば、(メタ)アクリル系モノマー、およびスチレン系モノマー);硬化性樹脂(例えば、(メタ)アクリル系樹脂、フッ素含有樹脂、およびウレタン樹脂);およびこれらの組み合わせが挙げられる。低屈折率部は、このような材料の溶液または分散液を塗工または印刷等することにより形成され得る。
Any suitable configuration can be adopted for the low refractive index portion as long as it has the above-mentioned desired porosity and refractive index. The low refractive index portion may be preferably formed by coating, printing or the like. As the material constituting the low refractive index portion, for example, the materials described in International Publication No. 2004/113966, JP2013-254183A, and JP2012-189802 can be adopted. Specifically, for example, silica-based compounds; hydrolyzable silanes and / or silsesquioxane, and partial hydrolysates and dehydration condensates thereof; organic polymers; silicon compounds containing silanol groups; silicates. Active silica obtained by contact with an acid or ion exchange resin; polymerizable monomer (eg, (meth) acrylic monomer, and styrene monomer); curable resin (eg, (meth) acrylic resin, fluorine-containing resin). , And urethane resin); and combinations thereof. The low refractive index portion can be formed by applying or printing a solution or dispersion of such a material.
低屈折率部における空隙(孔)のサイズは、空隙(孔)の長軸の直径および短軸の直径のうち、長軸の直径を指すものとする。空隙(孔)のサイズは、例えば、2nm~500nmである。空隙(孔)のサイズは、例えば2nm以上であり、好ましくは5nm以上であり、より好ましくは10nm以上であり、さらに好ましくは20nm以上である。一方、空隙(孔)のサイズは、例えば500nm以下であり、好ましくは200nm以下であり、より好ましくは100nm以下である。空隙(孔)のサイズの範囲は、例えば2nm~500nmであり、好ましくは5nm~500nmであり、より好ましくは10nm~200nmであり、さらに好ましくは20nm~100nmである。空隙(孔)のサイズは、目的および用途等に応じて、所望のサイズに調整することができる。空隙(孔)のサイズは、BET試験法により定量化できる。
The size of the void (hole) in the low refractive index portion shall indicate the diameter of the major axis among the diameter of the major axis and the diameter of the minor axis of the void (hole). The size of the voids (pores) is, for example, 2 nm to 500 nm. The size of the voids (pores) is, for example, 2 nm or more, preferably 5 nm or more, more preferably 10 nm or more, and further preferably 20 nm or more. On the other hand, the size of the void (pore) is, for example, 500 nm or less, preferably 200 nm or less, and more preferably 100 nm or less. The size range of the voids (pores) is, for example, 2 nm to 500 nm, preferably 5 nm to 500 nm, more preferably 10 nm to 200 nm, and even more preferably 20 nm to 100 nm. The size of the void (hole) can be adjusted to a desired size according to the purpose, application, and the like. The size of the voids (pores) can be quantified by the BET test method.
空隙(孔)のサイズは、BET試験法により定量化できる。具体的には、比表面積測定装置(マイクロメリティック社製:ASAP2020)のキャピラリに、サンプル(形成された空隙層)を0.1g投入した後、室温で24時間、減圧乾燥を行って、空隙構造内の気体を脱気する。そして、上記サンプルに窒素ガスを吸着させることで吸着等温線を描き、細孔分布を求める。これによって、空隙サイズが評価できる。
The size of the void (hole) can be quantified by the BET test method. Specifically, 0.1 g of a sample (formed void layer) was put into the capillary of a specific surface area measuring device (manufactured by Micromeritic Co., Ltd .: ASAP2020), and then dried under reduced pressure at room temperature for 24 hours to allow voids. Degas the gas in the structure. Then, by adsorbing nitrogen gas to the sample, an adsorption isotherm is drawn and the pore distribution is obtained. Thereby, the void size can be evaluated.
低屈折率部のヘイズは、例えば5%未満であり、好ましくは3%未満である。一方、ヘイズは、例えば0.1%以上であり、好ましくは0.2%以上である。ヘイズの範囲は、例えば0.1%以上5%未満であり、好ましくは0.2%以上3%未満である。ヘイズは、例えば、以下のような方法により測定できる。なお、ヘイズは、低屈折率部の透明性の指標である。
空隙層(低屈折率部)を50mm×50mmのサイズにカットし、ヘイズメーター(村上色彩技術研究所社製:HM-150)にセットしてヘイズを測定する。ヘイズ値については、以下の式より算出する。
ヘイズ(%)=[拡散透過率(%)/全光線透過率(%)]×100(%) The haze of the low refractive index portion is, for example, less than 5%, preferably less than 3%. On the other hand, the haze is, for example, 0.1% or more, preferably 0.2% or more. The range of haze is, for example, 0.1% or more and less than 5%, preferably 0.2% or more and less than 3%. The haze can be measured by, for example, the following method. The haze is an index of transparency of the low refractive index portion.
The void layer (low refractive index portion) is cut into a size of 50 mm × 50 mm and set in a haze meter (manufactured by Murakami Color Technology Research Institute: HM-150) to measure haze. The haze value is calculated from the following formula.
Haze (%) = [Diffusion transmittance (%) / Total light transmittance (%)] x 100 (%)
空隙層(低屈折率部)を50mm×50mmのサイズにカットし、ヘイズメーター(村上色彩技術研究所社製:HM-150)にセットしてヘイズを測定する。ヘイズ値については、以下の式より算出する。
ヘイズ(%)=[拡散透過率(%)/全光線透過率(%)]×100(%) The haze of the low refractive index portion is, for example, less than 5%, preferably less than 3%. On the other hand, the haze is, for example, 0.1% or more, preferably 0.2% or more. The range of haze is, for example, 0.1% or more and less than 5%, preferably 0.2% or more and less than 3%. The haze can be measured by, for example, the following method. The haze is an index of transparency of the low refractive index portion.
The void layer (low refractive index portion) is cut into a size of 50 mm × 50 mm and set in a haze meter (manufactured by Murakami Color Technology Research Institute: HM-150) to measure haze. The haze value is calculated from the following formula.
Haze (%) = [Diffusion transmittance (%) / Total light transmittance (%)] x 100 (%)
上記内部に空隙を有する低屈折率部としては、例えば、多孔質層、および/または空気層を少なくとも一部に有する低屈折率部が挙げられる。多孔質層は、代表的には、エアロゲル、および/または粒子(例えば、中空微粒子および/または多孔質粒子)を含む。低屈折率部は、好ましくはナノポーラス層(具体的には、90%以上の微細孔の直径が10-1nm~103nmの範囲内の多孔質層)であり得る。
Examples of the low refractive index portion having voids inside include a low refractive index portion having a porous layer and / or an air layer in at least a part thereof. The porous layer typically includes airgel and / or particles (eg, hollow fine particles and / or porous particles). The low refractive index portion may be preferably a nanoporous layer (specifically, a porous layer having a diameter of 90% or more of micropores in the range of 10-1 nm to 103 nm).
上記粒子としては、任意の適切な粒子を採用し得る。粒子は、代表的には、シリカ系化合物からなる。粒子の形状としては、例えば、球状、板状、針状、ストリング状、およびブドウの房状が挙げられる。ストリング状の粒子としては、例えば、球状、板状、または針状の形状を有する複数の粒子が数珠状に連なった粒子、短繊維状の粒子(例えば、特開2001-188104号公報に記載の短繊維状の粒子)、およびこれらの組み合わせが挙げられる。ストリング状の粒子は、直鎖状であってもよく、分岐状であってもよい。ブドウの房状の粒子としては、例えば、球状、板状、および針状の粒子が複数凝集してブドウの房状になったものが挙げられる。粒子の形状は、例えば透過電子顕微鏡で観察することによって確認できる。
As the above particles, any suitable particles can be adopted. The particles are typically composed of silica-based compounds. The shape of the particles includes, for example, spherical, plate-like, needle-like, string-like, and grape tuft-like. As the string-shaped particles, for example, a particle in which a plurality of particles having a spherical, plate-like, or needle-like shape are connected in a bead shape, and a staple-like particle (for example, Japanese Patent Application Laid-Open No. 2001-188104) are described. Short fibrous particles), and combinations thereof. The string-shaped particles may be linear or branched. Examples of the tufted particles of grape include those in which a plurality of spherical, plate-shaped, and needle-shaped particles are aggregated to form a tuft of grape. The shape of the particles can be confirmed, for example, by observing with a transmission electron microscope.
低屈折率部の厚みは、好ましくは0.2μm~5μmであり、より好ましくは0.3μm~3μmである。低屈折率部の厚みがこのような範囲であれば、破損防止効果が顕著なものとなる。さらに、上記所望の厚みの比を容易に実現することができる。
The thickness of the low refractive index portion is preferably 0.2 μm to 5 μm, and more preferably 0.3 μm to 3 μm. If the thickness of the low refractive index portion is within such a range, the damage prevention effect becomes remarkable. Further, the desired thickness ratio can be easily realized.
以下、低屈折率部の具体的な構成の一例について説明する。本実施形態の低屈折率部は、微細な空隙構造を形成する一種類または複数種類の構成単位からなり、該構成単位同士が触媒作用を介して化学的に結合している。構成単位の形状としては、例えば、粒子状、繊維状、棒状、平板状が挙げられる。構成単位は、1つの形状のみを有していてもよく、2つ以上の形状を組み合わせて有していてもよい。以下においては、主として、低屈折率部が上記微細孔粒子どうしが化学的に結合している多孔体の空隙層である場合について説明する。
Hereinafter, an example of a specific configuration of the low refractive index portion will be described. The low refractive index portion of the present embodiment is composed of one or a plurality of types of structural units that form a fine void structure, and the structural units are chemically bonded to each other via catalytic action. Examples of the shape of the structural unit include a particle shape, a fibrous shape, a rod shape, and a flat plate shape. The structural unit may have only one shape, or may have a combination of two or more shapes. In the following, a case where the low refractive index portion is mainly a void layer of a porous body in which the fine pore particles are chemically bonded to each other will be described.
このような空隙層は、空隙層形成工程において、例えば微細孔粒子どうしを化学的に結合させることにより形成され得る。なお、本発明の実施形態において「粒子」(例えば、上記微細孔粒子)の形状は特に限定されず、例えば球状でもよく他の形状でもよい。また、本発明の実施形態において、上記微細孔粒子は、例えば、ゾルゲル数珠状粒子、ナノ粒子(中空ナノシリカ・ナノバルーン粒子)、ナノ繊維等であってもよい。微細孔粒子は、代表的には無機物を含む。無機物の具体例としては、ケイ素(Si)、マグネシウム(Mg)、アルミニウム(Al)、チタン(Ti)、亜鉛(Zn)、ジルコニウム(Zr)が挙げられる。これらは、単独で用いてもよく、2種以上を併用してもよい。1つの実施形態においては、上記微細孔粒子は、例えばケイ素化合物の微細孔粒子であり、上記多孔体は、例えばシリコーン多孔体(シリカおよび/またはシルセスキオキサンを構成単位として含む多孔体も含む)である。上記ケイ素化合物の微細孔粒子は、例えば、ゲル状シリカ化合物の粉砕体を含む。また、多孔質層および/または空気層を少なくとも一部に有する低屈折率部の別形態としては、例えば、ナノファイバー等の繊維状物質からなり、該繊維状物質が絡まり合い空隙が形成されて層を成している空隙層がある。このような空隙層の製造方法は特に限定されず、例えば、上記微細孔粒子どうしが化学的に結合している多孔体の空隙層の場合と同様である。さらに別の形態としては、中空ナノ粒子やナノクレイを用いた空隙層、中空ナノバルーンやフッ化マグネシウムを用いて形成した空隙層が挙げられる。空隙層は、単一の構成物質からなる空隙層であってもよいし、複数の構成物質からなる空隙層であってもよい。空隙層は、単一の上記形態で構成されていてもよく、複数の上記形態を含んで構成されていてもよい。
Such a void layer can be formed, for example, by chemically bonding fine pore particles to each other in the void layer forming step. In the embodiment of the present invention, the shape of the "particle" (for example, the fine pore particles) is not particularly limited, and may be spherical or another shape, for example. Further, in the embodiment of the present invention, the fine pore particles may be, for example, sol-gel beaded particles, nanoparticles (hollow nanosilica / nanoparticles), nanoparticles and the like. The micropore particles typically contain inorganic substances. Specific examples of the inorganic substance include silicon (Si), magnesium (Mg), aluminum (Al), titanium (Ti), zinc (Zn), and zirconium (Zr). These may be used alone or in combination of two or more. In one embodiment, the micropore particles are, for example, micropore particles of a silicon compound, and the porous body also includes, for example, a silicone porous body (silica and / or a porous body containing silsesquioxane as a constituent unit). ). The fine pore particles of the silicon compound include, for example, a pulverized body of a gel-like silica compound. Further, as another form of the low refractive index portion having a porous layer and / or an air layer at least in a part thereof, for example, it is made of a fibrous substance such as nanofibers, and the fibrous substances are entangled to form voids. There is a layered void layer. The method for producing such a void layer is not particularly limited, and is the same as, for example, in the case of a porous void layer in which the fine pore particles are chemically bonded to each other. Still another form includes a void layer using hollow nanoparticles and nanoclay, and a void layer formed by using hollow nanoballoons and magnesium fluoride. The void layer may be a void layer composed of a single constituent substance, or may be a void layer composed of a plurality of constituent substances. The void layer may be composed of the single above-mentioned form, or may be composed of a plurality of the above-mentioned forms.
本実施形態においては、多孔体の多孔質構造は、例えば、孔構造が連続した連泡構造体であり得る。連泡構造体とは、例えば上記シリコーン多孔体において、三次元的に孔構造が連なっていることを意味し、孔構造の内部空隙が連続している状態ともいえる。多孔質体が連泡構造を有することにより、空隙率を高めることが可能である。ただし、中空シリカのような独泡粒子(個々に孔構造を有する粒子)を使用する場合には、連泡構造を形成できない。一方、例えばシリカゾル粒子(ゾルを形成するゲル状ケイ素化合物の粉砕物)を使用する場合、当該粒子が三次元の樹状構造を有するために、塗工膜(ゲル状ケイ素化合物の粉砕物を含むゾルの塗工膜)中で当該樹状粒子が沈降および堆積することで、容易に連泡構造を形成することが可能である。低屈折率部は、より好ましくは、連泡構造が複数の細孔分布を含むモノリス構造を有する。モノリス構造は、例えば、ナノサイズの微細な空隙が存在する構造と、同ナノ空隙が集合した連泡構造とを含む階層構造を意味する。モノリス構造を形成する場合、例えば、微細な空隙で膜強度を付与しつつ、粗大な連泡空隙で高い空隙率を付与し、膜強度と高空隙率とを両立することができる。このようなモノリス構造は、好ましくは、シリカゾル粒子に粉砕する前段階のゲル(ゲル状ケイ素化合物)において、生成する空隙構造の細孔分布を制御することにより形成され得る。また例えば、ゲル状ケイ素化合物を粉砕する際、粉砕後のシリカゾル粒子の粒度分布を所望のサイズに制御することにより、モノリス構造を形成することができる。
In the present embodiment, the porous structure of the porous body can be, for example, a continuous foam structure having a continuous pore structure. The continuous foam structure means that, for example, in the above-mentioned silicone porous body, the pore structures are three-dimensionally connected, and it can be said that the internal voids of the pore structure are continuous. Since the porous body has a continuous foam structure, it is possible to increase the porosity. However, when using single-foam particles (particles having individual pore structures) such as hollow silica, a continuous-foam structure cannot be formed. On the other hand, for example, when silica sol particles (crushed product of gel-like silicon compound forming a sol) are used, the coating film (crushed product of gel-like silicon compound) is included because the particles have a three-dimensional dendritic structure. The dendritic particles settle and deposit in the sol coating film), so that a continuous foam structure can be easily formed. The low refractive index portion more preferably has a monolithic structure in which the continuous foam structure includes a plurality of pore distributions. The monolith structure means, for example, a hierarchical structure including a structure in which nano-sized fine voids are present and a continuous bubble structure in which the nano-voids are aggregated. When forming a monolith structure, for example, it is possible to impart a high porosity to coarse continuous bubble voids while imparting film strength to fine voids, and to achieve both film strength and high porosity. Such a monolith structure can be preferably formed by controlling the pore distribution of the void structure formed in the gel (gel-like silicon compound) before pulverizing into silica sol particles. Further, for example, when the gelled silicon compound is pulverized, a monolith structure can be formed by controlling the particle size distribution of the silica sol particles after pulverization to a desired size.
低屈折率部は、例えば上記のようにゲル状化合物の粉砕物を含み、当該粉砕物同士が化学的に結合している。低屈折率部における粉砕物同士の化学的な結合(化学結合)の形態は、特に制限されず、例えば架橋結合、共有結合、水素結合が挙げられる。
The low refractive index portion contains, for example, a pulverized product of a gel-like compound as described above, and the pulverized products are chemically bonded to each other. The form of the chemical bond (chemical bond) between the pulverized substances in the low refractive index portion is not particularly limited, and examples thereof include a crosslink bond, a covalent bond, and a hydrogen bond.
低屈折率部における上記粉砕物の体積平均粒子径は、例えば0.10μm以上であり、好ましくは0.20μm以上であり、より好ましくは0.40μm以上である。一方、体積平均粒子径は、例えば2.00μm以下であり、好ましくは1.50μm以下であり、より好ましくは1.00μm以下である。体積平均粒子径の範囲は、例えば0.10μm~2.00μmであり、好ましくは0.20μm~1.50μmであり、より好ましくは0.40μm~1.00μmである。粒度分布は、例えば、動的光散乱法、レーザー回折法等の粒度分布評価装置、および走査型電子顕微鏡(SEM)、透過型電子顕微鏡(TEM)等の電子顕微鏡等により測定することができる。なお、体積平均粒子径は、粉砕物の粒度のバラツキの指標である。
The volume average particle size of the pulverized product in the low refractive index portion is, for example, 0.10 μm or more, preferably 0.20 μm or more, and more preferably 0.40 μm or more. On the other hand, the volume average particle diameter is, for example, 2.00 μm or less, preferably 1.50 μm or less, and more preferably 1.00 μm or less. The range of the volume average particle diameter is, for example, 0.10 μm to 2.00 μm, preferably 0.20 μm to 1.50 μm, and more preferably 0.40 μm to 1.00 μm. The particle size distribution can be measured by, for example, a particle size distribution evaluation device such as a dynamic light scattering method or a laser diffraction method, and an electron microscope such as a scanning electron microscope (SEM) or a transmission electron microscope (TEM). The volume average particle size is an index of variation in the particle size of the pulverized product.
ゲル状化合物の種類は、特に制限されない。ゲル状化合物としては、例えばゲル状ケイ素化合物が挙げられる。
The type of gel compound is not particularly limited. Examples of the gel-like compound include a gel-like silicon compound.
また、低屈折率部(空隙層)においては、例えば、含まれるケイ素原子がシロキサン結合していることが好ましい。具体例として、空隙層に含まれる全ケイ素原子のうち、未結合のケイ素原子(つまり、残留シラノール)の割合は、例えば50%未満であり、好ましくは30%以下であり、より好ましくは15%以下である。
Further, in the low refractive index portion (void layer), for example, it is preferable that the contained silicon atom is siloxane bonded. As a specific example, the proportion of unbonded silicon atoms (that is, residual silanol) in the total silicon atoms contained in the void layer is, for example, less than 50%, preferably 30% or less, and more preferably 15%. It is as follows.
以下、このような低屈折率部の形成方法の一例について説明する。
Hereinafter, an example of a method for forming such a low refractive index portion will be described.
当該方法は、代表的には、樹脂フィルム上に低屈折率部(空隙層)の前駆体である空隙構造を形成する前駆体形成工程、および、前駆体形成工程後に当該前駆体内部で架橋反応を起こさせる架橋反応工程、を含む。当該方法は、微細孔粒子を含む含有液(以下、「微細孔粒子含有液」または単に「含有液」という場合がある。)を作製する含有液作製工程、および、当該含有液を乾燥させる乾燥工程をさらに含み、前駆体形成工程において、乾燥体中の微細孔粒子どうしを化学的に結合させて前駆体を形成する。含有液は、特に限定されず、例えば、微細孔粒子を含む懸濁液である。なお、以下においては、主として、微細孔粒子がゲル状化合物の粉砕物であり、空隙層がゲル状化合物の粉砕物を含む多孔体(好ましくはシリコーン多孔体)である場合について説明する。ただし、低屈折率部は、微細孔粒子がゲル状化合物の粉砕物以外である場合も、同様に形成することができる。
This method is typically a precursor forming step of forming a void structure which is a precursor of a low refractive index portion (void layer) on a resin film, and a crosslinking reaction inside the precursor after the precursor forming step. Includes a cross-linking reaction step, which causes The method is a step of preparing a containing liquid for producing a containing liquid containing fine pore particles (hereinafter, may be referred to as "fine pore particle-containing liquid" or simply "containing liquid"), and a drying process for drying the containing liquid. Further including a step, in the precursor forming step, the fine pore particles in the dried body are chemically bonded to each other to form a precursor. The containing liquid is not particularly limited, and is, for example, a suspension containing fine pore particles. In the following, a case where the fine pore particles are mainly pulverized gel-like compounds and the void layer is a porous body containing the pulverized gel-like compound (preferably a silicone porous body) will be described. However, the low refractive index portion can be similarly formed even when the fine pore particles are other than the pulverized product of the gel-like compound.
上記の方法によれば、例えば、非常に低い屈折率を有する低屈折率部(空隙層)が形成される。その理由は、例えば以下のように推測される。ただし、当該推測は、低屈折率部の形成方法を限定するものではない。
According to the above method, for example, a low refractive index portion (void layer) having a very low refractive index is formed. The reason is presumed as follows, for example. However, the guess does not limit the method of forming the low refractive index portion.
上記粉砕物は、ゲル状ケイ素化合物を粉砕したものであるため、粉砕前のゲル状ケイ素化合物の三次元構造が、三次元基本構造に分散された状態となっている。さらに、上記方法では、ゲル状ケイ素化合物の破砕物を樹脂フィルム上に塗工することで、三次元基本構造に基づく多孔性構造の前駆体が形成される。つまり、上記の方法によれば、ゲル状ケイ素化合物の三次元構造とは異なる、粉砕物の塗工による新たな多孔構造(三次元基本構造)が形成される。このため、最終的に得られる空隙層においては、例えば空気層と同程度に機能する低屈折率を実現することができる。さらに、上記の方法においては、砕物同士を化学的に結合させるため、三次元基本構造が固定化される。このため、最終的に得られる空隙層は、空隙を有する構造であるにもかかわらず、十分な強度と可撓性とを維持することができる。
Since the crushed product is a crushed gel-like silicon compound, the three-dimensional structure of the gel-like silicon compound before crushing is dispersed in the three-dimensional basic structure. Further, in the above method, a crushed product of a gel-like silicon compound is applied onto a resin film to form a precursor having a porous structure based on a three-dimensional basic structure. That is, according to the above method, a new porous structure (three-dimensional basic structure) is formed by coating the pulverized material, which is different from the three-dimensional structure of the gel-like silicon compound. Therefore, in the finally obtained void layer, it is possible to realize a low refractive index that functions to the same extent as, for example, an air layer. Further, in the above method, the three-dimensional basic structure is immobilized because the crushed substances are chemically bonded to each other. Therefore, the finally obtained void layer can maintain sufficient strength and flexibility even though it has a structure having voids.
低屈折率部の具体的な構成および形成方法の詳細は、例えば国際公開第2019/151073号に記載されている。当該公報の記載は、本明細書に参考として援用される。
Details of the specific configuration and forming method of the low refractive index portion are described in, for example, International Publication No. 2019/151573. The description of this publication is incorporated herein by reference.
E-4.粘着剤層
粘着剤層を構成する粘着剤としては、任意の適切な粘着剤が用いられ得る。粘着剤としては、代表的には、アクリル系粘着剤(アクリル系粘着剤組成物)が挙げられる。アクリル系粘着剤組成物は業界で周知であるので、詳細な説明は省略する。粘着剤層の厚みは、例えば3μm~200μmである。粘着剤層43および44の構成材料および厚みは、それぞれ、同一であってもよく異なっていてもよい。なお、低屈折率部に隣接して粘着剤層が配置される場合には、当該粘着剤層は、代表的には、粘着剤層を構成する粘着剤が通常の状態では低屈折率部の空隙に浸透しない程度の硬さを有する。このような粘着剤層の貯蔵弾性率は、例えば1.3×105(Pa)~1.0×107(Pa)であり得る。 E-4. Adhesive Layer As the adhesive constituting the adhesive layer, any suitable adhesive may be used. Typical examples of the pressure-sensitive adhesive include an acrylic pressure-sensitive adhesive (acrylic pressure-sensitive adhesive composition). Since the acrylic pressure-sensitive adhesive composition is well known in the industry, detailed description thereof will be omitted. The thickness of the pressure-sensitive adhesive layer is, for example, 3 μm to 200 μm. The constituent materials and thicknesses of the pressure-sensitive adhesive layers 43 and 44 may be the same or different, respectively. When the pressure-sensitive adhesive layer is arranged adjacent to the low-refractive index portion, the pressure-sensitive adhesive layer is typically a low-refractive index portion when the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer is in a normal state. It has a hardness that does not penetrate the voids. The storage elastic modulus of such a pressure-sensitive adhesive layer can be, for example, 1.3 × 10 5 (Pa) to 1.0 × 10 7 (Pa).
粘着剤層を構成する粘着剤としては、任意の適切な粘着剤が用いられ得る。粘着剤としては、代表的には、アクリル系粘着剤(アクリル系粘着剤組成物)が挙げられる。アクリル系粘着剤組成物は業界で周知であるので、詳細な説明は省略する。粘着剤層の厚みは、例えば3μm~200μmである。粘着剤層43および44の構成材料および厚みは、それぞれ、同一であってもよく異なっていてもよい。なお、低屈折率部に隣接して粘着剤層が配置される場合には、当該粘着剤層は、代表的には、粘着剤層を構成する粘着剤が通常の状態では低屈折率部の空隙に浸透しない程度の硬さを有する。このような粘着剤層の貯蔵弾性率は、例えば1.3×105(Pa)~1.0×107(Pa)であり得る。 E-4. Adhesive Layer As the adhesive constituting the adhesive layer, any suitable adhesive may be used. Typical examples of the pressure-sensitive adhesive include an acrylic pressure-sensitive adhesive (acrylic pressure-sensitive adhesive composition). Since the acrylic pressure-sensitive adhesive composition is well known in the industry, detailed description thereof will be omitted. The thickness of the pressure-sensitive adhesive layer is, for example, 3 μm to 200 μm. The constituent materials and thicknesses of the pressure-sensitive adhesive layers 43 and 44 may be the same or different, respectively. When the pressure-sensitive adhesive layer is arranged adjacent to the low-refractive index portion, the pressure-sensitive adhesive layer is typically a low-refractive index portion when the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer is in a normal state. It has a hardness that does not penetrate the voids. The storage elastic modulus of such a pressure-sensitive adhesive layer can be, for example, 1.3 × 10 5 (Pa) to 1.0 × 10 7 (Pa).
F.低屈折率層
低屈折率層50の詳細な構成は、基本的には、低屈折率補強部の低屈折率部に関してE-3項で説明したとおりである。以下、低屈折率層に特徴的な構成についてのみ説明する。 F. Low Refractive Index Layer The detailed configuration of the lowrefractive index layer 50 is basically as described in Section E-3 with respect to the low refractive index portion of the low refractive index reinforcing portion. Hereinafter, only the configuration characteristic of the low refractive index layer will be described.
低屈折率層50の詳細な構成は、基本的には、低屈折率補強部の低屈折率部に関してE-3項で説明したとおりである。以下、低屈折率層に特徴的な構成についてのみ説明する。 F. Low Refractive Index Layer The detailed configuration of the low
図1Aのように低屈折率層が空隙部に充満している場合、低屈折率層の厚みは接着層の厚みと同じであり、例えば50μm以上、60μm以上、70μm以上、80μm以上、90μm以上、または100μm以上であって、1000μm以下、900μm以下、800μm以下、700μm以下、600μm以下または500μm以下であり得る。また、図1B又は1Cの構成の場合、低屈折率層の厚みは、光漏れを抑制できる限り特に限定されないが、その下限は、好ましくは0.6μm以上、0.75μm以上、0.80μm以上であり、その上限は、好ましくは3μm以下、2μm以下である。
When the low refractive index layer fills the void portion as shown in FIG. 1A, the thickness of the low refractive index layer is the same as the thickness of the adhesive layer, for example, 50 μm or more, 60 μm or more, 70 μm or more, 80 μm or more, 90 μm or more. , Or 100 μm or more, and can be 1000 μm or less, 900 μm or less, 800 μm or less, 700 μm or less, 600 μm or less, or 500 μm or less. Further, in the case of the configuration of FIG. 1B or 1C, the thickness of the low refractive index layer is not particularly limited as long as light leakage can be suppressed, but the lower limit thereof is preferably 0.6 μm or more, 0.75 μm or more, 0.80 μm or more. The upper limit thereof is preferably 3 μm or less and 2 μm or less.
低屈折率層における空隙(孔)のサイズは、好ましくは400nm以下であり、より好ましくは300nm以下であり、さらに好ましくは200nm以下であり、特に好ましくは100nm以下である。低屈折率層における空隙(孔)のサイズがこのような範囲であれば、水分の浸入を良好に抑制することができるので、結露を良好に抑制することができる。結果として、光漏れを良好に抑制することができる。空隙(孔)のサイズは小さいほど好ましく、その下限は例えば2nmであり得る。
The size of the voids (pores) in the low refractive index layer is preferably 400 nm or less, more preferably 300 nm or less, still more preferably 200 nm or less, and particularly preferably 100 nm or less. When the size of the voids (pores) in the low refractive index layer is within such a range, the infiltration of water can be satisfactorily suppressed, so that dew condensation can be satisfactorily suppressed. As a result, light leakage can be satisfactorily suppressed. The smaller the size of the void (pore), the more preferable, and the lower limit thereof can be, for example, 2 nm.
以下、実施例によって本発明を具体的に説明するが、本発明はこれら実施例によって限定されるものではない。なお、各特性の測定方法は以下の通りである。
Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples. The measurement method for each characteristic is as follows.
(I)低屈折率層および低屈折率補強部の低屈折率部の屈折率
アクリルフィルムに低屈折率層を形成した後に、50mm×50mmのサイズにカットし、これを粘着層を介してガラス板(厚み:3mm)の表面に貼合した。上記ガラス板の裏面中央部(直径20mm程度)を黒マジックで塗りつぶして、該ガラス板の裏面で反射しないサンプルとした。エリプソメーター(J.A.Woollam Japan社製:VASE)に上記サンプルをセットし、500nmの波長、入射角50~80度の条件で、屈折率を測定した。
(II)輝度ムラ
実施例および比較例で得られた光学積層体について、光学積層体の導光板端部からLEDの光を入射し、輝度ムラを目視により観察した。以下の基準で評価した。
○:積層体全面について輝度(明るさ)が均一である
×:光漏れが認められる、輝度が不均一である、および/または、明るい領域が少ない
(III)強度
実施例および比較例で得られた光学積層体を取り扱う際の導光板とプリズムフィルムとの剥離の有無を調べた。以下の基準で評価した。
○:剥離は発生せず、一体物として問題なく取り扱うことができた
×:剥離が発生した
(IV)光漏れ
実施例および比較例で得られた光学積層体を、20℃および98%RHに制御された恒温恒湿槽に1時間入れて加湿処理した。加湿処理後の光学積層体に導光板の入光側端部からLED光を入射させ、光漏れの有無を目視により調べた。以下の基準で評価した。
○:光漏れが認められ輝度が不均一である
×:光漏れは認められず輝度は均一である (I) Refractive index of the low refractive index layer and the low refractive index portion of the low refractive index reinforcing portion After forming the low refractive index layer on the acrylic film, it is cut into a size of 50 mm × 50 mm, and this is cut into glass via an adhesive layer. It was affixed to the surface of a plate (thickness: 3 mm). The central portion (about 20 mm in diameter) of the back surface of the glass plate was painted with black magic to prepare a sample that does not reflect on the back surface of the glass plate. The above sample was set in an ellipsometer (manufactured by JA Woollam Japan: VASE), and the refractive index was measured under the conditions of a wavelength of 500 nm and an incident angle of 50 to 80 degrees.
(II) Luminance unevenness With respect to the optical laminates obtained in Examples and Comparative Examples, LED light was incident from the end of the light guide plate of the optical laminate, and the luminance unevenness was visually observed. It was evaluated according to the following criteria.
◯: Luminance (brightness) is uniform over the entire surface of the laminate ×: Light leakage is observed, the brightness is non-uniform, and / or there are few bright regions (III) Intensity Obtained in Examples and Comparative Examples. It was investigated whether or not the light guide plate and the prism film were peeled off when handling the optical laminate. It was evaluated according to the following criteria.
◯: Peeling did not occur and could be handled as an integral body without any problem. ×: Peeling occurred (IV) Light leakage The optical laminates obtained in Examples and Comparative Examples were heated to 20 ° C. and 98% RH. It was placed in a controlled constant temperature and humidity chamber for 1 hour for humidification treatment. LED light was incident on the optical laminate after the humidification treatment from the end of the light guide plate on the incoming light side, and the presence or absence of light leakage was visually inspected. It was evaluated according to the following criteria.
◯: Light leakage is observed and the brightness is non-uniform. ×: No light leakage is observed and the brightness is uniform.
アクリルフィルムに低屈折率層を形成した後に、50mm×50mmのサイズにカットし、これを粘着層を介してガラス板(厚み:3mm)の表面に貼合した。上記ガラス板の裏面中央部(直径20mm程度)を黒マジックで塗りつぶして、該ガラス板の裏面で反射しないサンプルとした。エリプソメーター(J.A.Woollam Japan社製:VASE)に上記サンプルをセットし、500nmの波長、入射角50~80度の条件で、屈折率を測定した。
(II)輝度ムラ
実施例および比較例で得られた光学積層体について、光学積層体の導光板端部からLEDの光を入射し、輝度ムラを目視により観察した。以下の基準で評価した。
○:積層体全面について輝度(明るさ)が均一である
×:光漏れが認められる、輝度が不均一である、および/または、明るい領域が少ない
(III)強度
実施例および比較例で得られた光学積層体を取り扱う際の導光板とプリズムフィルムとの剥離の有無を調べた。以下の基準で評価した。
○:剥離は発生せず、一体物として問題なく取り扱うことができた
×:剥離が発生した
(IV)光漏れ
実施例および比較例で得られた光学積層体を、20℃および98%RHに制御された恒温恒湿槽に1時間入れて加湿処理した。加湿処理後の光学積層体に導光板の入光側端部からLED光を入射させ、光漏れの有無を目視により調べた。以下の基準で評価した。
○:光漏れが認められ輝度が不均一である
×:光漏れは認められず輝度は均一である (I) Refractive index of the low refractive index layer and the low refractive index portion of the low refractive index reinforcing portion After forming the low refractive index layer on the acrylic film, it is cut into a size of 50 mm × 50 mm, and this is cut into glass via an adhesive layer. It was affixed to the surface of a plate (thickness: 3 mm). The central portion (about 20 mm in diameter) of the back surface of the glass plate was painted with black magic to prepare a sample that does not reflect on the back surface of the glass plate. The above sample was set in an ellipsometer (manufactured by JA Woollam Japan: VASE), and the refractive index was measured under the conditions of a wavelength of 500 nm and an incident angle of 50 to 80 degrees.
(II) Luminance unevenness With respect to the optical laminates obtained in Examples and Comparative Examples, LED light was incident from the end of the light guide plate of the optical laminate, and the luminance unevenness was visually observed. It was evaluated according to the following criteria.
◯: Luminance (brightness) is uniform over the entire surface of the laminate ×: Light leakage is observed, the brightness is non-uniform, and / or there are few bright regions (III) Intensity Obtained in Examples and Comparative Examples. It was investigated whether or not the light guide plate and the prism film were peeled off when handling the optical laminate. It was evaluated according to the following criteria.
◯: Peeling did not occur and could be handled as an integral body without any problem. ×: Peeling occurred (IV) Light leakage The optical laminates obtained in Examples and Comparative Examples were heated to 20 ° C. and 98% RH. It was placed in a controlled constant temperature and humidity chamber for 1 hour for humidification treatment. LED light was incident on the optical laminate after the humidification treatment from the end of the light guide plate on the incoming light side, and the presence or absence of light leakage was visually inspected. It was evaluated according to the following criteria.
◯: Light leakage is observed and the brightness is non-uniform. ×: No light leakage is observed and the brightness is uniform.
[製造例1]低屈折率層形成用塗工液の調製
(1)ケイ素化合物のゲル化
2.2gのジメチルスルホキシド(DMSO)に、ケイ素化合物の前駆体であるメチルトリメトキシシラン(MTMS)を0.95g溶解させて混合液Aを調製した。この混合液Aに、0.01mol/Lのシュウ酸水溶液を0.5g添加し、室温で30分撹拌を行うことでMTMSを加水分解して、トリス(ヒドロキシ)メチルシランを含む混合液Bを生成した。
5.5gのDMSOに、28重量%のアンモニア水0.38g、および純水0.2gを添加した後、さらに、上記混合液Bを追添し、室温で15分撹拌することで、トリス(ヒドロキシ)メチルシランのゲル化を行い、ゲル状ケイ素化合物を含む混合液Cを得た。
(2)熟成処理
上記のように調製したゲル状ケイ素化合物を含む混合液Cを、そのまま、40℃で20時間インキュベートして、熟成処理を行った。
(3)粉砕処理
つぎに、上記のように熟成処理したゲル状ケイ素化合物を、スパチュラを用いて数mm~数cmサイズの顆粒状に砕いた。次いで、混合液Cにイソプロピルアルコール(IPA)を40g添加し、軽く撹拌した後、室温で6時間静置して、ゲル中の溶媒および触媒をデカンテーションした。同様のデカンテーション処理を3回行うことにより、溶媒置換し、混合液Dを得た。次いで、混合液D中のゲル状ケイ素化合物を粉砕処理(高圧メディアレス粉砕)した。粉砕処理(高圧メディアレス粉砕)は、ホモジナイザー(エスエムテー社製、商品名「UH-50」)を使用し、5ccのスクリュー瓶に、混合液D中のゲル状化合物1.85gおよびIPAを1.15g秤量した後、50W、20kHzの条件で2分間の粉砕で行った。
この粉砕処理によって、上記混合液D中のゲル状ケイ素化合物が粉砕されたことにより、該混合液D’は、粉砕物のゾル液となった。混合液D’に含まれる粉砕物の粒度バラツキを示す体積平均粒子径を、動的光散乱式ナノトラック粒度分析計(日機装社製、UPA-EX150型)にて確認したところ、0.50~0.70であった。さらに、このゾル液(混合液D’)0.75gに対し、光塩基発生剤(和光純薬工業株式会社:商品名WPBG266)の1.5重量%濃度MEK(メチルエチルケトン)溶液を0.062g、ビス(トリメトキシシリル)エタンの5%濃度MEK溶液を0.036gの比率で添加し、低屈折率層形成用塗工液Aを得た。 [Production Example 1] Preparation of coating liquid for forming a low refractive index layer (1) Gelation of silicon compound Methyltrimethoxysilane (MTMS), which is a precursor of a silicon compound, is added to 2.2 g of dimethyl sulfoxide (DMSO). Mixture A was prepared by dissolving 0.95 g. MTMS is hydrolyzed by adding 0.5 g of a 0.01 mol / L oxalic acid aqueous solution to this mixture A and stirring at room temperature for 30 minutes to produce a mixture B containing tris (hydroxy) methylsilane. did.
After adding 0.38 g of 28% by weight aqueous ammonia and 0.2 g of pure water to 5.5 g of DMSO, the above mixture B was further added, and the mixture was stirred at room temperature for 15 minutes to obtain Tris ( Hydroxy) methylsilane was gelled to obtain a mixed solution C containing a gelled silicon compound.
(2) Aging treatment The mixed solution C containing the gelled silicon compound prepared as described above was incubated as it was at 40 ° C. for 20 hours for aging treatment.
(3) Crushing Treatment Next, the gelled silicon compound aged as described above was crushed into granules having a size of several mm to several cm using a spatula. Then, 40 g of isopropyl alcohol (IPA) was added to the mixture C, and the mixture was lightly stirred and then allowed to stand at room temperature for 6 hours to decant the solvent and catalyst in the gel. The same decantation treatment was carried out three times to replace the solvent, and a mixed solution D was obtained. Next, the gelled silicon compound in the mixed solution D was pulverized (high pressure medialess pulverization). For the pulverization treatment (high-pressure medialess pulverization), a homogenizer (manufactured by SMTE, trade name “UH-50”) was used, and 1.85 g of the gel compound and IPA in the mixed solution D were placed in a 5 cc screw bottle. After weighing 15 g, the mixture was pulverized for 2 minutes under the conditions of 50 W and 20 kHz.
By this pulverization treatment, the gelled silicon compound in the mixed solution D was pulverized, so that the mixed solution D'became a sol solution of the pulverized product. The volume average particle size showing the variation in the particle size of the pulverized material contained in the mixed solution D'was confirmed by a dynamic light scattering type nanotrack particle size analyzer (UPA-EX150 type manufactured by Nikkiso Co., Ltd.) and found to be 0.50 to. It was 0.70. Further, 0.062 g of a 1.5 wt% MEK (methyl ethyl ketone) solution of a photobase generator (Wako Pure Chemical Industries, Ltd .: trade name WPBG266) was added to 0.75 g of this sol solution (mixed solution D'). A 5% concentration MEK solution of bis (trimethoxysilyl) ethane was added at a ratio of 0.036 g to obtain a coating liquid A for forming a low refractive index layer.
(1)ケイ素化合物のゲル化
2.2gのジメチルスルホキシド(DMSO)に、ケイ素化合物の前駆体であるメチルトリメトキシシラン(MTMS)を0.95g溶解させて混合液Aを調製した。この混合液Aに、0.01mol/Lのシュウ酸水溶液を0.5g添加し、室温で30分撹拌を行うことでMTMSを加水分解して、トリス(ヒドロキシ)メチルシランを含む混合液Bを生成した。
5.5gのDMSOに、28重量%のアンモニア水0.38g、および純水0.2gを添加した後、さらに、上記混合液Bを追添し、室温で15分撹拌することで、トリス(ヒドロキシ)メチルシランのゲル化を行い、ゲル状ケイ素化合物を含む混合液Cを得た。
(2)熟成処理
上記のように調製したゲル状ケイ素化合物を含む混合液Cを、そのまま、40℃で20時間インキュベートして、熟成処理を行った。
(3)粉砕処理
つぎに、上記のように熟成処理したゲル状ケイ素化合物を、スパチュラを用いて数mm~数cmサイズの顆粒状に砕いた。次いで、混合液Cにイソプロピルアルコール(IPA)を40g添加し、軽く撹拌した後、室温で6時間静置して、ゲル中の溶媒および触媒をデカンテーションした。同様のデカンテーション処理を3回行うことにより、溶媒置換し、混合液Dを得た。次いで、混合液D中のゲル状ケイ素化合物を粉砕処理(高圧メディアレス粉砕)した。粉砕処理(高圧メディアレス粉砕)は、ホモジナイザー(エスエムテー社製、商品名「UH-50」)を使用し、5ccのスクリュー瓶に、混合液D中のゲル状化合物1.85gおよびIPAを1.15g秤量した後、50W、20kHzの条件で2分間の粉砕で行った。
この粉砕処理によって、上記混合液D中のゲル状ケイ素化合物が粉砕されたことにより、該混合液D’は、粉砕物のゾル液となった。混合液D’に含まれる粉砕物の粒度バラツキを示す体積平均粒子径を、動的光散乱式ナノトラック粒度分析計(日機装社製、UPA-EX150型)にて確認したところ、0.50~0.70であった。さらに、このゾル液(混合液D’)0.75gに対し、光塩基発生剤(和光純薬工業株式会社:商品名WPBG266)の1.5重量%濃度MEK(メチルエチルケトン)溶液を0.062g、ビス(トリメトキシシリル)エタンの5%濃度MEK溶液を0.036gの比率で添加し、低屈折率層形成用塗工液Aを得た。 [Production Example 1] Preparation of coating liquid for forming a low refractive index layer (1) Gelation of silicon compound Methyltrimethoxysilane (MTMS), which is a precursor of a silicon compound, is added to 2.2 g of dimethyl sulfoxide (DMSO). Mixture A was prepared by dissolving 0.95 g. MTMS is hydrolyzed by adding 0.5 g of a 0.01 mol / L oxalic acid aqueous solution to this mixture A and stirring at room temperature for 30 minutes to produce a mixture B containing tris (hydroxy) methylsilane. did.
After adding 0.38 g of 28% by weight aqueous ammonia and 0.2 g of pure water to 5.5 g of DMSO, the above mixture B was further added, and the mixture was stirred at room temperature for 15 minutes to obtain Tris ( Hydroxy) methylsilane was gelled to obtain a mixed solution C containing a gelled silicon compound.
(2) Aging treatment The mixed solution C containing the gelled silicon compound prepared as described above was incubated as it was at 40 ° C. for 20 hours for aging treatment.
(3) Crushing Treatment Next, the gelled silicon compound aged as described above was crushed into granules having a size of several mm to several cm using a spatula. Then, 40 g of isopropyl alcohol (IPA) was added to the mixture C, and the mixture was lightly stirred and then allowed to stand at room temperature for 6 hours to decant the solvent and catalyst in the gel. The same decantation treatment was carried out three times to replace the solvent, and a mixed solution D was obtained. Next, the gelled silicon compound in the mixed solution D was pulverized (high pressure medialess pulverization). For the pulverization treatment (high-pressure medialess pulverization), a homogenizer (manufactured by SMTE, trade name “UH-50”) was used, and 1.85 g of the gel compound and IPA in the mixed solution D were placed in a 5 cc screw bottle. After weighing 15 g, the mixture was pulverized for 2 minutes under the conditions of 50 W and 20 kHz.
By this pulverization treatment, the gelled silicon compound in the mixed solution D was pulverized, so that the mixed solution D'became a sol solution of the pulverized product. The volume average particle size showing the variation in the particle size of the pulverized material contained in the mixed solution D'was confirmed by a dynamic light scattering type nanotrack particle size analyzer (UPA-EX150 type manufactured by Nikkiso Co., Ltd.) and found to be 0.50 to. It was 0.70. Further, 0.062 g of a 1.5 wt% MEK (methyl ethyl ketone) solution of a photobase generator (Wako Pure Chemical Industries, Ltd .: trade name WPBG266) was added to 0.75 g of this sol solution (mixed solution D'). A 5% concentration MEK solution of bis (trimethoxysilyl) ethane was added at a ratio of 0.036 g to obtain a coating liquid A for forming a low refractive index layer.
[製造例2]低屈折率層形成用塗工液の調製
製造例1と同様にしてゾル液(混合液D’)を調製した。このゾル液(混合液D’)0.75gに対し、光塩基発生剤(和光純薬工業株式会社:商品名WPBG266)の1.5重量%濃度MEK(メチルエチルケトン)溶液を0.300g、ビス(トリメトキシシリル)エタンの5%濃度MEK溶液を0.090gの比率で添加し、低屈折率層形成用塗工液Bを得た。 [Production Example 2] Preparation of coating liquid for forming a low refractive index layer A sol liquid (mixed liquid D') was prepared in the same manner as in Production Example 1. To 0.75 g of this sol solution (mixed solution D'), 0.300 g of a 1.5 wt% MEK (methyl ethyl ketone) solution of a photobase generator (Wako Pure Chemical Industries, Ltd .: trade name WPBG266) was added to bis ( A 5% concentration MEK solution of trimethoxysilyl) ethane was added at a ratio of 0.090 g to obtain a coating liquid B for forming a low refractive index layer.
製造例1と同様にしてゾル液(混合液D’)を調製した。このゾル液(混合液D’)0.75gに対し、光塩基発生剤(和光純薬工業株式会社:商品名WPBG266)の1.5重量%濃度MEK(メチルエチルケトン)溶液を0.300g、ビス(トリメトキシシリル)エタンの5%濃度MEK溶液を0.090gの比率で添加し、低屈折率層形成用塗工液Bを得た。 [Production Example 2] Preparation of coating liquid for forming a low refractive index layer A sol liquid (mixed liquid D') was prepared in the same manner as in Production Example 1. To 0.75 g of this sol solution (mixed solution D'), 0.300 g of a 1.5 wt% MEK (methyl ethyl ketone) solution of a photobase generator (Wako Pure Chemical Industries, Ltd .: trade name WPBG266) was added to bis ( A 5% concentration MEK solution of trimethoxysilyl) ethane was added at a ratio of 0.090 g to obtain a coating liquid B for forming a low refractive index layer.
[製造例3]粘着剤の調製
攪拌羽根、温度計、窒素ガス導入管、冷却器を備えた4つ口フラスコに、ブチルアクリレート90.7部、N-アクリロイルモルホリン6部、アクリル酸3部、2-ヒドロキシブチルアクリレート0.3部、重合開始剤として2,2’-アゾビスイソブチロニトリル0.1重量部を酢酸エチル100gと共に仕込み、緩やかに攪拌しながら窒素ガスを導入して窒素置換した後、フラスコ内の液温を55℃付近に保って8時間重合反応を行い、アクリル系ポリマー溶液を調製した。得られたアクリル系ポリマー溶液の固形分100部に対して、イソシアネート架橋剤(日本ポリウレタン工業社製のコロネートL,トリメチロールプロパンのトリレンジイソシアネートのアダクト体)0.2部、ベンゾイルパーオキサイド(日本油脂社製のナイパーBMT)0.3部、γ-グリシドキシプロピルメトキシシラン(信越化学工業社製:KBM-403)0.2部を配合したアクリル系粘着剤溶液を調製した。次いで、上記アクリル系粘着剤溶液を、シリコーン処理を施したポリエチレンテレフタレート(PET)フィルム(三菱化学ポリエステルフィルム社製、厚さ:38μm)の片面に、乾燥後の粘着剤層の厚さが所定の厚みになるように塗布し、150℃で3分間乾燥を行い、粘着剤層を形成した。 [Production Example 3] Preparation of Adhesive In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, and a cooler, 90.7 parts of butyl acrylate, 6 parts of N-acryloyl morpholine, 3 parts of acrylic acid, Add 0.3 part of 2-hydroxybutyl acrylate and 0.1 part by weight of 2,2'-azobisisobutyronitrile as a polymerization initiator together with 100 g of ethyl acetate, and introduce nitrogen gas with gentle stirring to replace nitrogen. After that, the liquid temperature in the flask was kept at around 55 ° C. and the polymerization reaction was carried out for 8 hours to prepare an acrylic polymer solution. 0.2 parts of isocyanate cross-linking agent (Coronate L manufactured by Nippon Polyurethane Industry Co., Ltd., trimethylolpropane tolylene diisocyanate adduct) and benzoyl peroxide (Japan) with respect to 100 parts of the solid content of the obtained acrylic polymer solution. An acrylic pressure-sensitive adhesive solution containing 0.3 part of Niper BMT manufactured by Yushi Co., Ltd. and 0.2 part of γ-glycidoxypropylmethoxysilane (manufactured by Shin-Etsu Chemical Industry Co., Ltd .: KBM-403) was prepared. Next, the acrylic pressure-sensitive adhesive solution was applied to one side of a polyethylene terephthalate (PET) film (manufactured by Mitsubishi Chemical Polyester Film Co., Ltd., thickness: 38 μm) treated with silicone, and the thickness of the pressure-sensitive adhesive layer after drying was predetermined. It was applied to a thickness and dried at 150 ° C. for 3 minutes to form an adhesive layer.
攪拌羽根、温度計、窒素ガス導入管、冷却器を備えた4つ口フラスコに、ブチルアクリレート90.7部、N-アクリロイルモルホリン6部、アクリル酸3部、2-ヒドロキシブチルアクリレート0.3部、重合開始剤として2,2’-アゾビスイソブチロニトリル0.1重量部を酢酸エチル100gと共に仕込み、緩やかに攪拌しながら窒素ガスを導入して窒素置換した後、フラスコ内の液温を55℃付近に保って8時間重合反応を行い、アクリル系ポリマー溶液を調製した。得られたアクリル系ポリマー溶液の固形分100部に対して、イソシアネート架橋剤(日本ポリウレタン工業社製のコロネートL,トリメチロールプロパンのトリレンジイソシアネートのアダクト体)0.2部、ベンゾイルパーオキサイド(日本油脂社製のナイパーBMT)0.3部、γ-グリシドキシプロピルメトキシシラン(信越化学工業社製:KBM-403)0.2部を配合したアクリル系粘着剤溶液を調製した。次いで、上記アクリル系粘着剤溶液を、シリコーン処理を施したポリエチレンテレフタレート(PET)フィルム(三菱化学ポリエステルフィルム社製、厚さ:38μm)の片面に、乾燥後の粘着剤層の厚さが所定の厚みになるように塗布し、150℃で3分間乾燥を行い、粘着剤層を形成した。 [Production Example 3] Preparation of Adhesive In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, and a cooler, 90.7 parts of butyl acrylate, 6 parts of N-acryloyl morpholine, 3 parts of acrylic acid, Add 0.3 part of 2-hydroxybutyl acrylate and 0.1 part by weight of 2,2'-azobisisobutyronitrile as a polymerization initiator together with 100 g of ethyl acetate, and introduce nitrogen gas with gentle stirring to replace nitrogen. After that, the liquid temperature in the flask was kept at around 55 ° C. and the polymerization reaction was carried out for 8 hours to prepare an acrylic polymer solution. 0.2 parts of isocyanate cross-linking agent (Coronate L manufactured by Nippon Polyurethane Industry Co., Ltd., trimethylolpropane tolylene diisocyanate adduct) and benzoyl peroxide (Japan) with respect to 100 parts of the solid content of the obtained acrylic polymer solution. An acrylic pressure-sensitive adhesive solution containing 0.3 part of Niper BMT manufactured by Yushi Co., Ltd. and 0.2 part of γ-glycidoxypropylmethoxysilane (manufactured by Shin-Etsu Chemical Industry Co., Ltd .: KBM-403) was prepared. Next, the acrylic pressure-sensitive adhesive solution was applied to one side of a polyethylene terephthalate (PET) film (manufactured by Mitsubishi Chemical Polyester Film Co., Ltd., thickness: 38 μm) treated with silicone, and the thickness of the pressure-sensitive adhesive layer after drying was predetermined. It was applied to a thickness and dried at 150 ° C. for 3 minutes to form an adhesive layer.
[製造例4]両面粘着剤層付積層体(低屈折率補強部)の作製
製造例1で調製した低屈折率層形成用塗工液Aを厚さ30μmの基材(アクリルフィルム)に塗工した。塗工層のウェット厚み(乾燥させる前の厚み)は約27μmであった。該塗工層を、温度100℃で1分処理して乾燥し、基材上に低屈折率部(厚み0.9μm)を形成した。得られた低屈折率部の屈折率は1.18であった。次に、基材/低屈折率部の積層体の両面に製造例3で形成した粘着剤層(低屈折率部側の粘着剤層の厚み10μm、基材側の粘着剤層の厚み75μm)を配置し、両面粘着剤層付積層体を作製した。 [Production Example 4] Preparation of a laminate with a double-sided adhesive layer (low refractive index reinforcing portion) The coating liquid A for forming a low refractive index layer prepared in Production Example 1 is applied to a base material (acrylic film) having a thickness of 30 μm. I worked on it. The wet thickness (thickness before drying) of the coating layer was about 27 μm. The coated layer was treated at a temperature of 100 ° C. for 1 minute and dried to form a low refractive index portion (thickness 0.9 μm) on the substrate. The refractive index of the obtained low refractive index portion was 1.18. Next, the pressure-sensitive adhesive layer formed in Production Example 3 on both sides of the laminate of the base material / low refractive index portion (thickness of the pressure-sensitive adhesive layer on the low-refractive index portion side is 10 μm, thickness of the pressure-sensitive adhesive layer on the base material side is 75 μm). Was arranged to prepare a laminate with a double-sided pressure-sensitive adhesive layer.
製造例1で調製した低屈折率層形成用塗工液Aを厚さ30μmの基材(アクリルフィルム)に塗工した。塗工層のウェット厚み(乾燥させる前の厚み)は約27μmであった。該塗工層を、温度100℃で1分処理して乾燥し、基材上に低屈折率部(厚み0.9μm)を形成した。得られた低屈折率部の屈折率は1.18であった。次に、基材/低屈折率部の積層体の両面に製造例3で形成した粘着剤層(低屈折率部側の粘着剤層の厚み10μm、基材側の粘着剤層の厚み75μm)を配置し、両面粘着剤層付積層体を作製した。 [Production Example 4] Preparation of a laminate with a double-sided adhesive layer (low refractive index reinforcing portion) The coating liquid A for forming a low refractive index layer prepared in Production Example 1 is applied to a base material (acrylic film) having a thickness of 30 μm. I worked on it. The wet thickness (thickness before drying) of the coating layer was about 27 μm. The coated layer was treated at a temperature of 100 ° C. for 1 minute and dried to form a low refractive index portion (thickness 0.9 μm) on the substrate. The refractive index of the obtained low refractive index portion was 1.18. Next, the pressure-sensitive adhesive layer formed in Production Example 3 on both sides of the laminate of the base material / low refractive index portion (thickness of the pressure-sensitive adhesive layer on the low-refractive index portion side is 10 μm, thickness of the pressure-sensitive adhesive layer on the base material side is 75 μm). Was arranged to prepare a laminate with a double-sided pressure-sensitive adhesive layer.
[実施例1]
製造例1で調製した低屈折率層形成用塗工液Aを導光板(アクリル板、厚み400μm、導光方向の全長85mm、幅60mm、屈折率1.49)上に塗工および乾燥して、低屈折率層(屈折率1.18、厚み1μm)を形成した。次いで、低屈折率層を、鉄製の棒(先端が100μm以下)で切削して、ドットパターンを形成した。さらに、低屈折率層の導光方向に沿った両端部をへらで除去し、当該除去部分に製造例4で作製した両面粘着剤層付積層体を貼り合わせ、低屈折率補強部とした。さらに、上記ドットパターンを形成した部分にエポキシ接着剤(東亜合成社製、製品名「LCR0632」)をインクジェットで印刷し、図2に示すようなパターンの接着層を形成した。低屈折率補強部および接着層を介して、導光板の上にプリズムフィルムを貼り合わせて光学積層体を作製した。得られた光学積層体において低屈折率補強部の厚みと接着層の厚みは同じ(115.9μm)であった。また、得られた光学積層体は、図1Cの構成に相当する。得られた光学積層体を上記(II)~(IV)の評価に供した。結果を表1に示す。 [Example 1]
The coating liquid A for forming a low refractive index layer prepared in Production Example 1 is coated and dried on a light guide plate (acrylic plate, thickness 400 μm, total length 85 mm in the light guide direction, width 60 mm, refractive index 1.49). , A low refractive index layer (refractive index 1.18, thickness 1 μm) was formed. Next, the low refractive index layer was cut with an iron rod (tip of 100 μm or less) to form a dot pattern. Further, both ends of the low refractive index layer along the light guide direction were removed with a spatula, and the laminate with the double-sided pressure-sensitive adhesive layer produced in Production Example 4 was attached to the removed portions to form a low refractive index reinforcing portion. Further, an epoxy adhesive (manufactured by Toagosei Corporation, product name "LCR0632") was printed by inkjet on the portion where the dot pattern was formed to form an adhesive layer having a pattern as shown in FIG. An optical laminate was produced by laminating a prism film on a light guide plate via a low refractive index reinforcing portion and an adhesive layer. In the obtained optical laminate, the thickness of the low refractive index reinforcing portion and the thickness of the adhesive layer were the same (115.9 μm). Further, the obtained optical laminate corresponds to the configuration shown in FIG. 1C. The obtained optical laminate was subjected to the evaluations (II) to (IV) above. The results are shown in Table 1.
製造例1で調製した低屈折率層形成用塗工液Aを導光板(アクリル板、厚み400μm、導光方向の全長85mm、幅60mm、屈折率1.49)上に塗工および乾燥して、低屈折率層(屈折率1.18、厚み1μm)を形成した。次いで、低屈折率層を、鉄製の棒(先端が100μm以下)で切削して、ドットパターンを形成した。さらに、低屈折率層の導光方向に沿った両端部をへらで除去し、当該除去部分に製造例4で作製した両面粘着剤層付積層体を貼り合わせ、低屈折率補強部とした。さらに、上記ドットパターンを形成した部分にエポキシ接着剤(東亜合成社製、製品名「LCR0632」)をインクジェットで印刷し、図2に示すようなパターンの接着層を形成した。低屈折率補強部および接着層を介して、導光板の上にプリズムフィルムを貼り合わせて光学積層体を作製した。得られた光学積層体において低屈折率補強部の厚みと接着層の厚みは同じ(115.9μm)であった。また、得られた光学積層体は、図1Cの構成に相当する。得られた光学積層体を上記(II)~(IV)の評価に供した。結果を表1に示す。 [Example 1]
The coating liquid A for forming a low refractive index layer prepared in Production Example 1 is coated and dried on a light guide plate (acrylic plate, thickness 400 μm, total length 85 mm in the light guide direction, width 60 mm, refractive index 1.49). , A low refractive index layer (refractive index 1.18, thickness 1 μm) was formed. Next, the low refractive index layer was cut with an iron rod (tip of 100 μm or less) to form a dot pattern. Further, both ends of the low refractive index layer along the light guide direction were removed with a spatula, and the laminate with the double-sided pressure-sensitive adhesive layer produced in Production Example 4 was attached to the removed portions to form a low refractive index reinforcing portion. Further, an epoxy adhesive (manufactured by Toagosei Corporation, product name "LCR0632") was printed by inkjet on the portion where the dot pattern was formed to form an adhesive layer having a pattern as shown in FIG. An optical laminate was produced by laminating a prism film on a light guide plate via a low refractive index reinforcing portion and an adhesive layer. In the obtained optical laminate, the thickness of the low refractive index reinforcing portion and the thickness of the adhesive layer were the same (115.9 μm). Further, the obtained optical laminate corresponds to the configuration shown in FIG. 1C. The obtained optical laminate was subjected to the evaluations (II) to (IV) above. The results are shown in Table 1.
[実施例2]
低屈折率層形成用塗工液Aの代わりに製造例2で調製した低屈折率層形成用塗工液Bを用いて低屈折率層(屈折率1.25、厚み1μm)を形成したこと以外は実施例1と同様にして光学積層体を作製した。得られた光学積層体を実施例1と同様の評価に供した。結果を表1に示す。 [Example 2]
A low refractive index layer (refractive index 1.25, thickness 1 μm) was formed by using the low refractive index layer forming coating liquid B prepared in Production Example 2 instead of the low refractive index layer forming coating liquid A. An optical laminate was produced in the same manner as in Example 1 except for the above. The obtained optical laminate was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
低屈折率層形成用塗工液Aの代わりに製造例2で調製した低屈折率層形成用塗工液Bを用いて低屈折率層(屈折率1.25、厚み1μm)を形成したこと以外は実施例1と同様にして光学積層体を作製した。得られた光学積層体を実施例1と同様の評価に供した。結果を表1に示す。 [Example 2]
A low refractive index layer (refractive index 1.25, thickness 1 μm) was formed by using the low refractive index layer forming coating liquid B prepared in Production Example 2 instead of the low refractive index layer forming coating liquid A. An optical laminate was produced in the same manner as in Example 1 except for the above. The obtained optical laminate was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
[実施例3]
実施例1と同様の導光板の導光方向に沿った両端部に製造例4で作製した両面粘着剤層付積層体を貼り合わせ、低屈折率補強部とした。さらに、導光板上に低屈折率層形成用塗工液Aを塗工および乾燥し、低屈折率補強部と同じ厚み(115.9μm)の低屈折率層を形成した。その後、エポキシ接着剤(東亜合成社製、製品名「LCR0632」)をインクジェットで実施例1と同様のドットパターンに印刷し、接着層を形成した。印刷した接着剤を低屈折率層に浸透させて低屈折率層の空隙部を埋めた後、プリズムフィルムをその上から貼り合わせ、光学積層体を得た。得られた光学積層体は、図1Aの構成に相当する。得られた光学積層体を実施例1と同様の評価に供した。結果を表1に示す。 [Example 3]
The laminate with the double-sided adhesive layer produced in Production Example 4 was bonded to both ends of the light guide plate along the light guide direction in the same manner as in Example 1 to form a low refractive index reinforcing portion. Further, the coating liquid A for forming the low refractive index layer A was applied and dried on the light guide plate to form a low refractive index layer having the same thickness (115.9 μm) as the low refractive index reinforcing portion. Then, an epoxy adhesive (manufactured by Toagosei Co., Ltd., product name "LCR0632") was printed on a dot pattern similar to that in Example 1 by inkjet to form an adhesive layer. The printed adhesive was infiltrated into the low refractive index layer to fill the voids in the low refractive index layer, and then a prism film was bonded over the prism film to obtain an optical laminate. The obtained optical laminate corresponds to the configuration of FIG. 1A. The obtained optical laminate was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
実施例1と同様の導光板の導光方向に沿った両端部に製造例4で作製した両面粘着剤層付積層体を貼り合わせ、低屈折率補強部とした。さらに、導光板上に低屈折率層形成用塗工液Aを塗工および乾燥し、低屈折率補強部と同じ厚み(115.9μm)の低屈折率層を形成した。その後、エポキシ接着剤(東亜合成社製、製品名「LCR0632」)をインクジェットで実施例1と同様のドットパターンに印刷し、接着層を形成した。印刷した接着剤を低屈折率層に浸透させて低屈折率層の空隙部を埋めた後、プリズムフィルムをその上から貼り合わせ、光学積層体を得た。得られた光学積層体は、図1Aの構成に相当する。得られた光学積層体を実施例1と同様の評価に供した。結果を表1に示す。 [Example 3]
The laminate with the double-sided adhesive layer produced in Production Example 4 was bonded to both ends of the light guide plate along the light guide direction in the same manner as in Example 1 to form a low refractive index reinforcing portion. Further, the coating liquid A for forming the low refractive index layer A was applied and dried on the light guide plate to form a low refractive index layer having the same thickness (115.9 μm) as the low refractive index reinforcing portion. Then, an epoxy adhesive (manufactured by Toagosei Co., Ltd., product name "LCR0632") was printed on a dot pattern similar to that in Example 1 by inkjet to form an adhesive layer. The printed adhesive was infiltrated into the low refractive index layer to fill the voids in the low refractive index layer, and then a prism film was bonded over the prism film to obtain an optical laminate. The obtained optical laminate corresponds to the configuration of FIG. 1A. The obtained optical laminate was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
[比較例1]
実施例1と同様の導光板の導光方向に沿った両端部に製造例4で作製した両面粘着剤層付積層体を貼り合わせ、低屈折率補強部とした。さらに、導光板上にエポキシ接着剤(東亜合成社製、製品名「LCR0632」)をインクジェットで実施例1と同様のドットパターンに印刷し、接着層を形成した。低屈折率補強部および接着層を介して、導光板の上にプリズムフィルムを貼り合わせて一体化した。次いで、導光板とプリズムフィルムとの間の空隙部にシリコーン系OCR(旭化成ワッカーシリコーン株式会社製、製品名「LUMISIL 202UV」、屈折率1.42)を流し込み、硬化させて、光学積層体を得た。得られた光学積層体を実施例1と同様の評価に供した。結果を表1に示す。 [Comparative Example 1]
The laminate with the double-sided adhesive layer produced in Production Example 4 was bonded to both ends of the light guide plate along the light guide direction in the same manner as in Example 1 to form a low refractive index reinforcing portion. Further, an epoxy adhesive (manufactured by Toagosei Co., Ltd., product name "LCR0632") was printed on the light guide plate by inkjet in the same dot pattern as in Example 1 to form an adhesive layer. A prism film was bonded and integrated on the light guide plate via a low refractive index reinforcing portion and an adhesive layer. Next, a silicone-based OCR (manufactured by Asahi Kasei Wacker Silicone Co., Ltd., product name "LUMISIL 202UV", refractive index 1.42) was poured into the gap between the light guide plate and the prism film and cured to obtain an optical laminate. rice field. The obtained optical laminate was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
実施例1と同様の導光板の導光方向に沿った両端部に製造例4で作製した両面粘着剤層付積層体を貼り合わせ、低屈折率補強部とした。さらに、導光板上にエポキシ接着剤(東亜合成社製、製品名「LCR0632」)をインクジェットで実施例1と同様のドットパターンに印刷し、接着層を形成した。低屈折率補強部および接着層を介して、導光板の上にプリズムフィルムを貼り合わせて一体化した。次いで、導光板とプリズムフィルムとの間の空隙部にシリコーン系OCR(旭化成ワッカーシリコーン株式会社製、製品名「LUMISIL 202UV」、屈折率1.42)を流し込み、硬化させて、光学積層体を得た。得られた光学積層体を実施例1と同様の評価に供した。結果を表1に示す。 [Comparative Example 1]
The laminate with the double-sided adhesive layer produced in Production Example 4 was bonded to both ends of the light guide plate along the light guide direction in the same manner as in Example 1 to form a low refractive index reinforcing portion. Further, an epoxy adhesive (manufactured by Toagosei Co., Ltd., product name "LCR0632") was printed on the light guide plate by inkjet in the same dot pattern as in Example 1 to form an adhesive layer. A prism film was bonded and integrated on the light guide plate via a low refractive index reinforcing portion and an adhesive layer. Next, a silicone-based OCR (manufactured by Asahi Kasei Wacker Silicone Co., Ltd., product name "LUMISIL 202UV", refractive index 1.42) was poured into the gap between the light guide plate and the prism film and cured to obtain an optical laminate. rice field. The obtained optical laminate was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
[比較例2]
低屈折率補強部を設けなかったこと以外は実施例1と同様にして光学積層体を作製した。得られた光学積層体を実施例1と同様の評価に供した。結果を表1に示す。 [Comparative Example 2]
An optical laminate was produced in the same manner as in Example 1 except that the low refractive index reinforcing portion was not provided. The obtained optical laminate was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
低屈折率補強部を設けなかったこと以外は実施例1と同様にして光学積層体を作製した。得られた光学積層体を実施例1と同様の評価に供した。結果を表1に示す。 [Comparative Example 2]
An optical laminate was produced in the same manner as in Example 1 except that the low refractive index reinforcing portion was not provided. The obtained optical laminate was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
[比較例3]
実施例1と同様の導光板の導光方向に沿った両端部に製造例4で作製した両面粘着剤層付積層体を貼り合わせ、低屈折率補強部とした。さらに、導光板上にエポキシ接着剤(東亜合成社製、製品名「LCR0632」)をインクジェットで実施例1と同様のドットパターンに印刷し、接着層を形成した。低屈折率補強部および接着層を介して、導光板の上にプリズムフィルムを貼り合わせて一体化し、光学積層体を得た。すなわち、低屈折率層を設けなかったこと以外は実施例1と同様にして光学積層体を作製した。得られた光学積層体を実施例1と同様の評価に供した。結果を表1に示す。 [Comparative Example 3]
The laminate with the double-sided adhesive layer produced in Production Example 4 was bonded to both ends of the light guide plate along the light guide direction in the same manner as in Example 1 to form a low refractive index reinforcing portion. Further, an epoxy adhesive (manufactured by Toagosei Co., Ltd., product name "LCR0632") was printed on the light guide plate by inkjet in the same dot pattern as in Example 1 to form an adhesive layer. A prism film was bonded and integrated on a light guide plate via a low refractive index reinforcing portion and an adhesive layer to obtain an optical laminate. That is, an optical laminate was produced in the same manner as in Example 1 except that the low refractive index layer was not provided. The obtained optical laminate was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
実施例1と同様の導光板の導光方向に沿った両端部に製造例4で作製した両面粘着剤層付積層体を貼り合わせ、低屈折率補強部とした。さらに、導光板上にエポキシ接着剤(東亜合成社製、製品名「LCR0632」)をインクジェットで実施例1と同様のドットパターンに印刷し、接着層を形成した。低屈折率補強部および接着層を介して、導光板の上にプリズムフィルムを貼り合わせて一体化し、光学積層体を得た。すなわち、低屈折率層を設けなかったこと以外は実施例1と同様にして光学積層体を作製した。得られた光学積層体を実施例1と同様の評価に供した。結果を表1に示す。 [Comparative Example 3]
The laminate with the double-sided adhesive layer produced in Production Example 4 was bonded to both ends of the light guide plate along the light guide direction in the same manner as in Example 1 to form a low refractive index reinforcing portion. Further, an epoxy adhesive (manufactured by Toagosei Co., Ltd., product name "LCR0632") was printed on the light guide plate by inkjet in the same dot pattern as in Example 1 to form an adhesive layer. A prism film was bonded and integrated on a light guide plate via a low refractive index reinforcing portion and an adhesive layer to obtain an optical laminate. That is, an optical laminate was produced in the same manner as in Example 1 except that the low refractive index layer was not provided. The obtained optical laminate was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
[比較例4]
実施例1と同様の導光板上にエポキシ接着剤(東亜合成社製、製品名「LCR0632」)をインクジェットで実施例1と同様のドットパターンに印刷し、接着層を形成した。接着層を介して、導光板の上にプリズムフィルムを貼り合わせて一体化し、光学積層体を得た。すなわち、低屈折率補強部および低屈折率層のいずれも設けなかったこと以外は実施例1と同様にして光学積層体を作製した。得られた光学積層体を実施例1と同様の評価に供した。結果を表1に示す。 [Comparative Example 4]
An epoxy adhesive (manufactured by Toagosei Corporation, product name "LCR0632") was printed on the same light guide plate as in Example 1 by inkjet in the same dot pattern as in Example 1 to form an adhesive layer. A prism film was laminated on a light guide plate via an adhesive layer and integrated to obtain an optical laminate. That is, an optical laminate was produced in the same manner as in Example 1 except that neither the low refractive index reinforcing portion nor the low refractive index layer was provided. The obtained optical laminate was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
実施例1と同様の導光板上にエポキシ接着剤(東亜合成社製、製品名「LCR0632」)をインクジェットで実施例1と同様のドットパターンに印刷し、接着層を形成した。接着層を介して、導光板の上にプリズムフィルムを貼り合わせて一体化し、光学積層体を得た。すなわち、低屈折率補強部および低屈折率層のいずれも設けなかったこと以外は実施例1と同様にして光学積層体を作製した。得られた光学積層体を実施例1と同様の評価に供した。結果を表1に示す。 [Comparative Example 4]
An epoxy adhesive (manufactured by Toagosei Corporation, product name "LCR0632") was printed on the same light guide plate as in Example 1 by inkjet in the same dot pattern as in Example 1 to form an adhesive layer. A prism film was laminated on a light guide plate via an adhesive layer and integrated to obtain an optical laminate. That is, an optical laminate was produced in the same manner as in Example 1 except that neither the low refractive index reinforcing portion nor the low refractive index layer was provided. The obtained optical laminate was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
表1から明らかなように、本発明の実施例によれば、輝度が高く、輝度ムラが抑制され、一体物としての強度に優れ、かつ、光漏れが抑制された光学積層体を得ることができる。導光板と光学部材との間の空隙部を高屈折材料で充填した比較例1は、明るい領域が少なく、かつ光漏れが認められた。補強部を設けなかった比較例2は一体物としての強度が不十分であった。低屈折率層を設けなかった比較例3は光漏れが認められた。低屈折率層および補強部を設けなかった比較例4は、一体物としての強度が不十分であり、かつ光漏れが認められた。
As is clear from Table 1, according to the embodiment of the present invention, it is possible to obtain an optical laminate having high brightness, suppression of brightness unevenness, excellent strength as an integral body, and suppression of light leakage. can. In Comparative Example 1 in which the gap between the light guide plate and the optical member was filled with a high-refractive-index material, there were few bright regions and light leakage was observed. Comparative Example 2 in which the reinforcing portion was not provided had insufficient strength as an integral body. In Comparative Example 3 in which the low refractive index layer was not provided, light leakage was observed. In Comparative Example 4 in which the low refractive index layer and the reinforcing portion were not provided, the strength as an integral body was insufficient and light leakage was observed.
本発明の光学積層体は、導光板を用いて光を取り出す光学装置(例えば、画像表示装置、照明装置)に好適に用いられ得る。
The optical laminate of the present invention can be suitably used for an optical device (for example, an image display device, a lighting device) that extracts light by using a light guide plate.
10 導光板
20 接着層
30 光学部材
40 低屈折率補強部
41 基材
42 低屈折率部
50 低屈折率層
100 光学積層体
101 光学積層体
102 光学積層体 10Light guide plate 20 Adhesive layer 30 Optical member 40 Low refractive index reinforcing part 41 Base material 42 Low refractive index part 50 Low refractive index layer 100 Optical laminated body 101 Optical laminated body 102 Optical laminated body
20 接着層
30 光学部材
40 低屈折率補強部
41 基材
42 低屈折率部
50 低屈折率層
100 光学積層体
101 光学積層体
102 光学積層体 10
Claims (9)
- 導光板と、
該導光板に平面視ドットパターンで配置された接着層と、
該導光板の導光方向に沿った両端部に配置された、低屈折率部を含む低屈折率補強部と、
該導光板に該接着層および該低屈折率補強部を介して積層された光学部材と、
を有し、
該接着層は、ドットの密度が該導光板の入光側から導光方向に沿って大きくなるようなパターンを形成し、
該導光板と該光学部材との間の該接着層および該低屈折率補強部が配置されていない領域において、該導光板の接着層側の面および該光学部材の接着層側の面の少なくとも一方に接するようにして低屈折率層が配置されており、
該低屈折率部および該低屈折率層の屈折率が1.30以下である、
光学積層体。 Light guide plate and
An adhesive layer arranged in a plan view dot pattern on the light guide plate,
A low refractive index reinforcing portion including a low refractive index portion arranged at both ends along the light guide direction of the light guide plate, and a low refractive index reinforcing portion.
An optical member laminated on the light guide plate via the adhesive layer and the low refractive index reinforcing portion,
Have,
The adhesive layer forms a pattern in which the density of dots increases from the light entrance side of the light guide plate along the light guide direction.
At least the surface of the light guide plate on the adhesive layer side and the surface of the optical member on the adhesive layer side in the region where the adhesive layer and the low refractive index reinforcing portion are not arranged between the light guide plate and the optical member. The low refractive index layer is arranged so as to be in contact with one side,
The refractive index of the low refractive index portion and the low refractive index layer is 1.30 or less.
Optical laminate. - 前記低屈折率層が、前記導光板の接着層側の面および前記光学部材の接着層側の面の両方に接するようにして配置されている、請求項1に記載の光学積層体。 The optical laminate according to claim 1, wherein the low refractive index layer is arranged so as to be in contact with both the surface of the light guide plate on the adhesive layer side and the surface of the optical member on the adhesive layer side.
- 前記低屈折率層が、前記導光板と前記光学部材との間の前記接着層および前記低屈折率補強部が配置されていない領域全域に充満している、請求項2に記載の光学積層体。 The optical laminate according to claim 2, wherein the low refractive index layer fills the entire region where the adhesive layer and the low refractive index reinforcing portion are not arranged between the light guide plate and the optical member. ..
- 前記低屈折率部および前記低屈折率層の屈折率が1.25以下である、請求項1から3のいずれかに記載の光学積層体。 The optical laminate according to any one of claims 1 to 3, wherein the low refractive index portion and the low refractive index layer have a refractive index of 1.25 or less.
- 前記低屈折率部および前記低屈折率層が、微細孔粒子同士が化学的に結合することにより形成された空隙層である、請求項1から4のいずれかに記載の光学積層体。 The optical laminate according to any one of claims 1 to 4, wherein the low refractive index portion and the low refractive index layer are void layers formed by chemically binding fine pore particles to each other.
- 前記低屈折率補強部が、基材と該基材に形成された低屈折率部と両面に最外層として設けられた粘着剤層とを有する、請求項1から5のいずれかに記載の光学積層体。 The optics according to any one of claims 1 to 5, wherein the low refractive index reinforcing portion has a base material, a low refractive index portion formed on the base material, and an adhesive layer provided as an outermost layer on both sides thereof. Laminated body.
- 前記低屈折率補強部の幅の合計が、前記導光板の幅の10%以下である、請求項1から6のいずれかに記載の光学積層体。 The optical laminate according to any one of claims 1 to 6, wherein the total width of the low refractive index reinforcing portions is 10% or less of the width of the light guide plate.
- 前記低屈折率補強部の全光線透過率が85%以上である、請求項1から7のいずれかに記載の光学積層体。 The optical laminate according to any one of claims 1 to 7, wherein the total light transmittance of the low refractive index reinforcing portion is 85% or more.
- 前記導光板の入光側と反対側の端部に低屈折率補強部がさらに設けられている、請求項1から8のいずれかに記載の光学積層体。 The optical laminate according to any one of claims 1 to 8, wherein a low refractive index reinforcing portion is further provided at an end portion of the light guide plate opposite to the light entering side.
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JP2020-159891 | 2020-09-24 | ||
JP2020159891A JP2022053201A (en) | 2020-09-24 | 2020-09-24 | Optical laminate |
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WO2022064782A1 true WO2022064782A1 (en) | 2022-03-31 |
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JP (1) | JP2022053201A (en) |
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Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH11224519A (en) * | 1998-02-09 | 1999-08-17 | Omron Corp | Surface light source device |
JP2003315792A (en) * | 2002-04-24 | 2003-11-06 | Nec Lcd Technologies Ltd | Liquid crystal display |
US20100067257A1 (en) * | 2008-09-17 | 2010-03-18 | 3M Innovative Properties Company | Patterned adhesives for reflectors |
WO2017086005A1 (en) * | 2015-11-19 | 2017-05-26 | ソニー株式会社 | Lighting system and display apparatus |
US20180224696A1 (en) * | 2017-02-04 | 2018-08-09 | Boe Technology Group Co., Ltd. | Backlight module, light guide panel assembly and manufacturing method therefor |
JP2018123299A (en) * | 2017-01-31 | 2018-08-09 | 日東電工株式会社 | Low-refractive-index layer-containing adhesive sheet, method for producing low-refractive-index layer-containing adhesive sheet, and optical device |
-
2020
- 2020-09-24 JP JP2020159891A patent/JP2022053201A/en active Pending
-
2021
- 2021-06-09 WO PCT/JP2021/021923 patent/WO2022064782A1/en active Application Filing
- 2021-06-22 TW TW110122773A patent/TW202212876A/en unknown
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH11224519A (en) * | 1998-02-09 | 1999-08-17 | Omron Corp | Surface light source device |
JP2003315792A (en) * | 2002-04-24 | 2003-11-06 | Nec Lcd Technologies Ltd | Liquid crystal display |
US20100067257A1 (en) * | 2008-09-17 | 2010-03-18 | 3M Innovative Properties Company | Patterned adhesives for reflectors |
WO2017086005A1 (en) * | 2015-11-19 | 2017-05-26 | ソニー株式会社 | Lighting system and display apparatus |
JP2018123299A (en) * | 2017-01-31 | 2018-08-09 | 日東電工株式会社 | Low-refractive-index layer-containing adhesive sheet, method for producing low-refractive-index layer-containing adhesive sheet, and optical device |
US20180224696A1 (en) * | 2017-02-04 | 2018-08-09 | Boe Technology Group Co., Ltd. | Backlight module, light guide panel assembly and manufacturing method therefor |
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TW202212876A (en) | 2022-04-01 |
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