Optical laminate, concave mirror, and method for manufacturing concave mirror

Abstract

The present invention relates to an optical laminate provided with a reflective film and a protective film on the reflective film, the protective film being provided with a first base film and an adhesive layer on the first base film, the adhesive layer-side surface of the protective film being bonded to the reflective film, and the adhesive layer-side surface of the protective film being bonded to the reflective film. The surface of the protective film on the adhesive layer side has a surface roughness Ra of 180 nm or less, and the amount of thermal deformation of the protective film at 110 DEG C is less than 1%.

Description

Technical Field

[0001] The present invention relates to an optical layered body, a concave mirror using the optical layered body, and a method for producing the concave mirror. Background Art

[0002] The driver of a vehicle looks forward through the front windshield and drives while visually observing the instruments on the dashboard. That is, the line of sight moves toward the instruments in the front and below. If the instruments can be observed while looking forward, the line of sight will not move, and it can be expected that driving performance (ultimately safety) will be improved. Based on this discovery, a head-up display (HUD) device was developed and put into practical use.

[0003] In the head-up display device, the image from the light source is formed as a virtual image on the front windshield in the instrument panel device, so that the driver can visually recognize it as an image. In order to project the image information from the light source without distortion, a mirror body with high mirror properties is required. In addition, in order to project the image information from the light source without reducing the brightness, a mirror body with high visible light reflectivity is required.

[0004] From the perspective of improving driving safety, head-up displays that can reduce the movement of viewpoints are gaining more and more attention, and the demand for mirror bodies used as reflectors is also increasing. In addition, for reasons such as low risk of damage due to accidents such as vehicle collisions and light weight, plastic substrates are used as support substrates constituting mirror bodies, and in particular, polycarbonate substrates are used for reasons of high heat resistance.

[0005] The conventional method for manufacturing a mirror body is usually as follows: a metal film is formed on a supporting substrate such as a polycarbonate substrate using an intermittent evaporation / sputtering device (e.g., Patent Document 1). However, the intermittent method has the following problems: low production efficiency, insufficient supply in response to the increasing demand for mirror bodies, and a mirror body that can be manufactured with good productivity is desired. In addition, the mirror body is required to have high reflectivity and suppress distortion of reflected light.

[0006] Therefore, a method for manufacturing a concave mirror using a reflective film that can be attached to a support has been studied. For example, Patent Document 2 discloses a reflective mirror (concave mirror) that is manufactured by insert molding and includes a substrate and a reflective sheet having a reflective film formed thereon. Insert molding allows the reflective sheet and the substrate to be integrally molded, so productivity is high.

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: Japanese Patent Application Publication No. 2009-265287

[0010] Patent Document 2: Japanese Patent Application Publication No. 2019-28422 Summary of the invention

[0011] Problems to be solved by the invention

[0012] As described above, in order to project the image information from the light source without distortion, the mirror body needs to have high mirror surface properties. Therefore, in order to prevent the reflective film from being damaged when manufacturing the reflective film or the concave mirror, it is considered to provide a protective film on the reflective film.

[0013] However, according to the research of the present inventors, it has been found that when insert molding as described in Patent Document 2 is performed, a protective film used may cause a decrease in the mirror surface properties of the concave mirror.

[0014] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an optical layered body capable of forming a concave mirror with high mirror surface properties, a concave mirror using the optical layered body, and a method for producing a concave mirror.

[0015] Solutions for solving problems

[0016] The present inventors have conducted intensive studies and have found that, in an optical laminate including a reflective film and a protective film, the above-mentioned problems can be solved by setting the surface roughness and thermal deformation amount of the protective film within specific ranges.

[0017] That is, the present invention is as follows.

[0018] [1]

[0019] An optical laminate, comprising a reflective film and a protective film on the reflective film, wherein the protective film comprises a first substrate film and an adhesive layer on the first substrate film, the surface of the protective film on the adhesive layer side is bonded to the reflective film, the surface roughness Ra of the surface of the protective film on the adhesive layer side is less than 180 nm, and the thermal deformation of the protective film at 110°C is less than 1%.

[0020] [2]

[0021] According to the optical laminate described in [1], the reflective film has a metal reflective layer and an optical adjustment layer in sequence on the second substrate film, the optical adjustment layer includes at least one high refractive index layer with a refractive index of 1.75 or more, and the surface of the protective film on the side of the adhesive layer is bonded to the surface of the reflective film on the side of the optical adjustment layer.

[0022] 〔3〕

[0023] A concave mirror comprises the optical layered body according to [1] or [2] and a substrate having a concave surface, wherein the surface of the optical layered body on the side of the reflective film and the surface of the substrate having a concave surface are laminated via an adhesive layer.

[0024] [4]

[0025] The concave mirror according to [3], wherein the optical stack and the base having a concave shape are stacked by film insert molding.

[0026] 〔5〕

[0027] The concave mirror according to [3], wherein the optical layered body and the base having the concave shape are stacked by lamination.

[0028] [6]

[0029] A method for manufacturing a concave mirror, wherein the concave mirror comprises an optical laminate as described in [1] or [2] and a substrate having a concave shape, the substrate having a concave shape is molded by film insert molding, and the optical laminate is laminated on the concave side of the substrate having a concave shape via an adhesive layer.

[0030] 〔7〕

[0031] A method for manufacturing a concave mirror, wherein the concave mirror comprises an optical layered body as described in [1] or [2] and a substrate having a concave surface, and the optical layered body is laminated on a concave surface of the substrate having a concave surface through an adhesive layer by lamination.

[0032] [8]

[0033] The method for manufacturing a concave mirror according to [7], wherein the lamination is vacuum lamination.

[0034] 〔9〕

[0035] The method for manufacturing a concave mirror according to [7], wherein the lamination is roller lamination.

[0036] Effects of the Invention

[0037] The present invention can provide an optical layered body capable of forming a concave mirror with high mirror surface properties, and a concave mirror using the optical layered body. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a schematic cross-sectional view of an optical layered body according to one embodiment of the present invention.

[0039] Figure 2This is a schematic cross-sectional view of an optical layered body according to one embodiment of the present invention.

[0040] Figure 3 This is a schematic cross-sectional view of a concave mirror according to an embodiment of the present invention.

[0041] Figure 4 This is a diagram for explaining a method for manufacturing a concave mirror using film insert molding.

[0042] Figure 5 This is a diagram for explaining a method for manufacturing a concave mirror using film insert molding.

[0043] Figure 6 This is a diagram for explaining a method for manufacturing a concave mirror using film insert molding. DETAILED DESCRIPTION

[0044] Hereinafter, this specific embodiment will be described in detail. It should be noted that the present invention is not limited to the embodiment described below.

[0045] [Optical laminate]

[0046] Figure 1 Schematic cross-sectional view of an optical layered body 1 according to one embodiment of the present invention is shown in FIG.

[0047] The optical laminate 1 of an embodiment of the present invention is an optical laminate having a reflective film 20 and a protective film 30 on the reflective film, wherein the protective film 30 has a first substrate film 14 and an adhesive layer 15 on the first substrate film 14, the surface of the protective film 30 on the adhesive layer 15 side is bonded to the reflective film 20, the surface roughness Ra of the surface of the protective film 30 on the adhesive layer 15 side is less than 180nm, and the thermal deformation of the protective film 30 at 110°C is less than 1%.

[0048] The optical laminate 1 of the embodiment of the present invention has a protective film 30 having a surface roughness Ra of 180 nm or less and a thermal deformation amount of less than 1% at 110° C. For example, when manufacturing a concave mirror by insert molding described later, the mold temperature is sometimes set to 60° C. to 300° C., and it is believed that the optical laminate is exposed to high temperature and the surface shape of the protective film is transferred to the reflective film. In this way, by using a protective film with high surface smoothness and little thermal deformation, the surface shape transferred to the reflective film 20 can be reduced in unevenness, and a concave mirror with high specularity can be manufactured with high productivity.

[0049] (Surface roughness Ra of protective film in optical laminate)

[0050] In the optical laminate of the embodiment of the present invention, the surface roughness Ra of the surface on the adhesive layer side of the protective film is less than 180 nm. If the surface roughness Ra exceeds 180 nm, when the optical laminate is exposed to high temperature during the manufacture of the concave mirror, the concave-convex shape of the surface on the adhesive layer side of the protective film is transferred to the reflective film, so the mirror property of the concave mirror is lost.

[0051] From the viewpoint of improving the mirror surface property, the surface roughness Ra of the protective film is preferably 100 nm or less, more preferably 50 nm or less, and further preferably 30 nm or less.

[0052] Here, the surface roughness Ra of the protective film in the optical laminate according to the embodiment of the present invention is obtained by peeling the protective film from the optical laminate and measuring the surface roughness of the pressure-sensitive adhesive layer-side surface of the peeled protective film.

[0053] The surface roughness Ra of the protective film can be measured in accordance with JIS B 0601:1994.

[0054] (Thermal deformation)

[0055] In the optical laminate of the embodiment of the present invention, the thermal deformation of the protective film at 110° C. is less than 1%. If the thermal deformation is 1% or more, when the optical laminate is exposed to high temperature during the manufacture of the concave mirror, the deformation of the surface of the protective film increases, and the deformed surface shape is transferred to the reflective film, so that the mirror surface of the concave mirror is lost.

[0056] From the viewpoint of improving the mirror surface property, the amount of thermal deformation of the protective film at 110° C. is preferably 0.5% or less, more preferably 0.3% or less.

[0057] The amount of thermal deformation of the protective film in the optical laminate according to the embodiment of the present invention is obtained by peeling the protective film from the optical laminate and measuring the amount of thermal deformation of the peeled protective film.

[0058] The thermal deformation amount of the protective film can be measured as the dimensional change rate when heated at 110° C. for 1 hour in accordance with JIS K7133 (1995).

[0059] It should be noted that, in this specification, the thermal deformation of the protective film is less than 1%, which means that the area change rate (%) of the protective film measured and calculated by the above-mentioned measurement method for the dimensions in the MD direction and the TD direction of the protective film is less than 1%. It is further preferred that the dimensional change rate (%) in the MD direction and the TD direction of the protective film is less than 1%. Here, the MD direction of the protective film refers to the longitudinal direction of the film (the flow direction of the film when it is formed), and the TD direction refers to the width direction of the film.

[0060] The amount of thermal deformation can be adjusted by, for example, the material of the first base film 14 in the protective film 30 or an annealing treatment.

[0061] The reflective film 20 in the optical laminate 1 of the embodiment of the present invention has a metal reflective layer 11 and an optical adjustment layer 13 in sequence on the second substrate film 10, the optical adjustment layer 13 includes at least one high refractive index layer with a refractive index of 1.75 or more, and the surface on the side of the adhesive layer 15 in the protective film 30 is preferably bonded to the surface on the side of the optical adjustment layer 13 in the reflective film 20.

[0062] By setting the reflective film to have the above-mentioned stacked structure, a concave mirror having excellent visible light reflection performance can be formed, which is preferred.

[0063] Hereinafter, each layer will be described in detail.

[0064] 〔Protective film〕

[0065] <First base film>

[0066] From the viewpoint of reducing the thermal deformation of the protective film, the material of the first substrate film 14 is preferably a member formed by homopolymers and copolymers such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate, polyimide, polyamide, polyvinyl chloride, polycarbonate (PC), cycloolefin polymer (COP), polystyrene, polycycloolefin, polyurethane, acrylic acid (PMMA), ABS, etc. Among the above materials, for example, polyethylene terephthalate, polyethylene naphthalate, acrylic acid, polycarbonate, cycloolefin polymer, ABS, and polyurethane are preferred. Among them, polyethylene terephthalate, cycloolefin polymer, polycarbonate, and acrylic acid are preferred from the perspective of a good balance between heat resistance and cost. The first substrate film 14 can be a single layer or a laminate.

[0067] The glass transition temperature of the material resin of the first base film is preferably 40° C. or higher, more preferably 60° C. or higher, from the viewpoint of reducing the amount of thermal deformation.

[0068] The thickness of the first substrate film 14 is not particularly limited. In view of ease of processing, the thickness of the first substrate film 14 is preferably 6 μm to 250 μm, for example. It is more preferably 20 μm or more, and further preferably 30 μm or more. In addition, it is more preferably 100 μm or less, and further preferably 75 μm or less. In addition, in order to enhance the adhesion with the layer formed on the first substrate film, plasma treatment, corona treatment, or even easy adhesion treatment may be performed.

[0069] <Adhesive layer>

[0070] The adhesive layer may be formed of an adhesive.

[0071] The adhesive forming the adhesive layer 15 is preferably a transparent adhesive, for example, any one of acrylic adhesive, rubber adhesive, silicone adhesive, polyester adhesive, urethane adhesive, epoxy adhesive, and polyether adhesive can be used alone, or two or more of them can be used in combination. From the viewpoints of transparency, processability, durability, etc., acrylic adhesive is preferably used.

[0072] The pressure-sensitive adhesive layer 15 is preferably protected by a release liner until being attached to the reflective film 20 .

[0073] The adhesive forming the adhesive layer 15 is preferably formed by an adhesive composition containing a base polymer (hereinafter sometimes referred to as "adhesive composition"). As the base polymer, a known polymer for an adhesive can be used. Wherein, the base polymer refers to the main component of the polymer contained in the adhesive composition. In addition, in the absence of special instructions, the "main component" in this specification refers to a component containing more than 50% by mass.

[0074] (Method for forming adhesive layer)

[0075] The adhesive layer can be formed, for example, by applying the adhesive composition on the first base film and removing the solvent etc. by drying. When applying the adhesive composition, one or more solvents may be appropriately added.

[0076] Alternatively, the adhesive layer may be formed, for example, by laminating the adhesive layer-side surface of a laminate of an adhesive layer and a release liner, the adhesive layer being formed from an adhesive composition on a release liner, to a first base film.

[0077] From the viewpoint of preventing foreign matter from being mixed in during lamination, the thickness of the adhesive layer is preferably 5 μm or more, more preferably 10 μm or more, and further preferably 25 μm or more. In addition, from the viewpoint of suppressing foaming caused by high temperature heating, the thickness of the adhesive layer is preferably 100 μm or less, more preferably 75 μm or less, and further preferably 50 μm or less.

[0078] The thickness of the adhesive layer can be measured by a dial gauge.

[0079] Various methods can be used as a coating method for the adhesive composition. Specifically, for example, roll coating, lick roller coating, gravure coating, reverse coating, roller brushing, spray coating, dip roll coating, rod coating, blade coating, air knife coating, curtain coating, die lip coating, extrusion coating using a die coater, etc. can be cited.

[0080] The heating and drying temperature is preferably 30°C to 200°C, more preferably 40°C to 180°C, and further preferably 80°C to 160°C. By setting the heating temperature to the above range, an adhesive layer having excellent adhesive properties can be obtained. The drying time can be appropriately used for an appropriate time. The above drying time is preferably 5 seconds to 20 minutes, more preferably 30 seconds to 10 minutes, and further preferably 1 minute to 8 minutes.

[0081] In the case of an active energy ray-curable adhesive, the adhesive composition can be irradiated with active energy rays such as ultraviolet rays to form an adhesive layer. Ultraviolet rays can be irradiated using a high-pressure mercury lamp, a low-pressure mercury lamp, a metal halide lamp, a chemical lamp, or the like.

[0082] The pressure-sensitive adhesive layer in the protective film may be protected by a release liner (separator) until it is bonded to the reflective film.

[0083] As the release liner, the release liner described later in the section of the method for forming the adhesive layer can be preferably used.

[0084] (Surface roughness Ra of protective film before lamination)

[0085] The protective film used in the manufacture of the optical laminate of the present embodiment, that is, the surface roughness Ra of the surface of the adhesive layer side of the protective film before laminating with the reflective film is preferably 180nm or less. From the viewpoint of improving the specularity, the surface roughness Ra of the protective film before laminating is more preferably 100nm or less, further preferably 50nm or less, and particularly preferably 30nm or less.

[0086] 〔Reflective film〕

[0087] The reflective film 20 in the optical laminate 1 of the embodiment of the present invention preferably has a laminated structure having a metal reflective layer 11 and an optical adjustment layer 13 in this order on a second base film 10. In addition, from the viewpoint of improving the visible light reflection performance of the concave mirror, the optical adjustment layer 13 preferably includes at least one high refractive index layer having a refractive index of 1.75 or more.

[0088] <Second base film>

[0089] The material of the second substrate film 10 is not particularly limited, for example, components formed by homopolymers and copolymers such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate, polyamide, polyvinyl chloride, polycarbonate (PC), cycloolefin polymer (COP), polystyrene, polypropylene (PP), polyethylene, polycycloolefin, polyurethane, acrylic acid (PMMA), ABS, etc. can be used. According to these components, it is transparent and has little optical absorption, and it does not affect the visual effect. Among them, in order to form various layers on the second substrate film 10 afterwards, it is preferably a material that can withstand high temperatures such as evaporation and sputtering. Therefore, among the above-mentioned materials, for example, polyethylene terephthalate, polyethylene naphthalate, acrylic acid, polycarbonate, cycloolefin polymer, ABS, polypropylene, and polyurethane are preferably used. Among them, from the perspective of good balance between heat resistance and cost, polyethylene terephthalate, cycloolefin polymer, polycarbonate, and acrylic acid are preferably used. The second substrate film 10 can be a monolayer or a laminate.

[0090] The thickness of the second substrate film 10 is not particularly limited. In view of ease of processing, the thickness of the second substrate film 10 is preferably 6 μm to 250 μm, for example. It is more preferably 20 μm or more, and further preferably 40 μm or more. In addition, it is more preferably 100 μm or less, and further preferably 75 μm or less. In addition, in order to enhance the adhesion with the layer formed on the second substrate film, plasma treatment, corona treatment, or even easy adhesion treatment may be performed.

[0091] If necessary, a hard coating layer such as a smoothness or anti-glare hard coating layer may be formed on the second base film 10. By providing the hard coating layer, scratch resistance can be improved.

[0092] The hard coat layer can be formed from a hard coat composition. More specifically, the hard coat layer can be formed by applying a solution containing a curable resin as the hard coat composition to the second base film 10 .

[0093] As the curable resin contained in the hard coating composition, thermosetting resins, ultraviolet curing resins, electron beam curing resins, etc. can be listed. As the type of curable resin, various resins such as polyester, acrylic acid, carbamate, acrylic acid carbamate, amide, silicone, silicate, epoxy, melamine, oxetane, and acrylic acid carbamate can be listed. These curable resins can be appropriately selected to be used in one or more. Among these, acrylic resins, acrylic acid carbamate resins, and epoxy resins are preferred from the perspectives of high hardness, ability to be ultraviolet cured, and excellent productivity.

[0094] The thickness of the hard coating layer is preferably 0.5 μm or more, more preferably 1.0 μm or more, and preferably 10 μm or less, more preferably 7.0 μm or less, and further preferably 5.0 μm or less. The thickness of the hard coating layer can be measured using, for example, a film thickness meter (digital micrometer) or an optical interference film thickness meter.

[0095] <Metal reflective layer>

[0096] The metal reflective layer 11 in this embodiment is preferably formed on the second base film 10. The metal reflective layer 11 is preferably a layer having a metallic luster. The material forming the metal reflective layer 11 is not particularly limited, and may include metal and resin. The metal reflective layer 11 may be a metal layer.

[0097] The case where the metal reflective layer 11 is a metal layer will be described.

[0098] It is needless to say that the metal reflective layer 11 can exert sufficient brilliance, and is preferably formed of a metal with a low melting point. The reason is that the metal reflective layer 11 is preferably formed by thin film growth using sputtering. For this reason, as the metal reflective layer 11, a metal with a melting point of about 1000°C or less is suitable, for example, preferably containing at least one metal selected from aluminum (Al), zinc (Zn), lead (Pb), copper (Cu), silver (Ag), and any one of alloys containing the metal as a main component.

[0099] In particular, the metal reflective layer 11 preferably contains aluminum or an aluminum alloy for reasons of brightness, stability, price, etc. When an aluminum alloy is used, the aluminum content is preferably 50 mass % or more.

[0100] The thickness of the metal reflective layer 11 is preferably 20 nm or more in order to give full play to the brilliance. On the other hand, it is preferably 100 nm or less in order to consider the productivity. For example, it is preferably 20 nm to 100 nm, and more preferably 30 nm to 70 nm. This thickness is also suitable for forming a uniform film with good productivity. In addition, the aesthetics of the concave mirror produced by laminating the optical laminate 1 on the substrate is also good.

[0101] <Optical Adjustment Layer>

[0102] The optical layered body 1 according to the embodiment of the present invention preferably has an optical adjustment layer 13 on the surface of the metal reflective layer 11 opposite to the second base film 10. The optical adjustment layer 13 according to the embodiment of the present invention preferably includes at least one high refractive index layer having a refractive index of 1.75 or more.

[0103] By including the high refractive index layer as the optical adjustment layer, the reflection spectrum can be adjusted and the reflectivity in the visible light region can be increased.

[0104] In this specification, unless otherwise specified, the "refractive index" means a value measured at a temperature of 25°C using light of a wavelength λ=550 nm in accordance with the provisions of JIS K0062:1992.

[0105] (High refractive index layer)

[0106] The high refractive index layer preferably included in the optical adjustment layer of the embodiment of the present invention has a refractive index of 1.75 or higher, more preferably 1.75 to 3.2, and even more preferably 1.80 to 2.40. When a plurality of high refractive index layers are provided, the refractive indexes of the high refractive index layers may be the same or different.

[0107] The high refractive index layer is preferably a layer formed by a metal oxide and / or a metal nitride. It should be noted that the metal elements contained in the metal oxide and the metal nitride referred to herein include semi-metallic elements such as Si. In addition, the metal oxide and / or the metal nitride include metal oxynitrides. In addition, the metal oxide can be an oxide of a single metal element (single oxide) or an oxide of multiple metal elements (composite oxide). Similarly, the metal nitride can be a nitride of a single metal element (single nitride) or a nitride of multiple metal elements (composite nitride).

[0108] Examples of the metal element include Ce, Nb, Si, Sb, Ti, Ta, Zr, and Zn.

[0109] More specifically, materials for the high refractive index layer include, for example, CeO2 (2.30), NbO (2.33), Nb2O3 (2.15), Nb2O5 (2.32), SiN (2.03), Sb2O3 (2.10), TiO2 (2.35), Ta2O5 (2.10), ZrO2 (2.05), ZnO (2.10), ZnS (2.30), tin-doped indium oxide (ITO), antimony-doped tin oxide (ATO), etc. (the values ​​in parentheses of the above materials are refractive indices).

[0110] In particular, the high refractive index layer preferably contains at least one selected from Nb, Si, and Ti, for example, preferably contains NbO x 、SiN x 、TiO x At least one of, more preferably NbO x (Niobium oxide).

[0111] Consider from the viewpoint of improving the reflectivity in the visible light region, the thickness of high refractive index layer is preferably more than 10nm, more preferably more than 20nm, further preferably more than 30nm.In addition, consider from the viewpoint of improving the reflectivity in the visible light region, the thickness of high refractive index layer is preferably below 100nm, more preferably below 80nm, further preferably below 70nm.

[0112] The optical adjustment layer may be a laminate of layers having different refractive indices, and may include a low refractive index layer in addition to a high refractive index layer.

[0113] like Figure 2 As shown, the optical layered body 1 according to the embodiment of the present invention preferably includes, as the optical adjustment layer 13 , a first low refractive index layer 13 a , the high refractive index layer 13 b , and a second low refractive index layer 13 c in this order from the metal reflective layer 11 side.

[0114] (Low refractive index layer)

[0115] The low refractive index layer is a layer having a lower refractive index than the high refractive index layer, and its refractive index is, for example, 1.35 to 1.55, preferably 1.40 to 1.50. There may be one or more low refractive index layers, and the refractive indexes of the low refractive index layers in the case of multiple low refractive index layers may be the same or different. For example, the optical adjustment layer may include two low refractive index layers, a first low refractive index layer and a second low refractive index layer, and the refractive index of the first low refractive index layer may be the same as or different from that of the second low refractive index layer.

[0116] Examples of the material of the low refractive index layer include metal oxides and metal fluorides.

[0117] It should be noted that the metal elements contained in the metal oxides and metal fluorides referred to herein include semi-metallic elements such as Si. In addition, metal oxides and / or metal fluorides include metal fluoride oxides. In addition, the metal oxide can be an oxide of a single metal element (single oxide) or an oxide of multiple metal elements (composite oxide). Similarly, the metal fluoride can be a fluoride of a single metal element (single fluoride) or a fluoride of multiple metal elements (composite fluoride).

[0118] Examples of the metal element include Si and Mg.

[0119] As a specific example of metal oxide, silicon oxide (SiO2: refractive index 1.46) can be listed. As a specific example of metal fluoride, magnesium fluoride and fluosilicic acid can be listed. Regarding the material of the first low refractive index layer and the second low refractive index layer, from the viewpoint of refractive index, magnesium fluoride and fluosilicic acid are preferably used, and from the viewpoints of ease of manufacture, mechanical strength, moisture resistance, etc., silicon oxide is preferably used. If various characteristics are comprehensively considered, silicon oxide is preferably used. In the case of having multiple low refractive index layers, the materials of the low refractive index layers can be the same or different, and preferably the low refractive index layers all contain silicon oxide.

[0120] Consider from the viewpoint of improving the reflectivity in the visible light region, the thickness of the first low refractive index layer is preferably more than 50nm, more preferably more than 66nm, further preferably more than 68nm.In addition, consider from the viewpoint of improving the reflectivity in the visible light region, the thickness of the first low refractive index layer is preferably below 100nm, more preferably below 78nm, further preferably below 75nm.

[0121] From the viewpoint of improving the reflectance in the visible light region, the upper limit of the thickness of the second low refractive index layer is preferably 50 nm or less, and more preferably 45 nm or less.

[0122] The laminated structure of the optical adjustment layer 13 preferably includes at least one high refractive index layer having a refractive index of 1.75 or higher, but is not particularly limited.

[0123] The optical layered body 1 may further include, for example, a layer made of titanium oxide or a mixture of the low refractive index material and the high refractive index material (such as a mixture of titanium oxide and silicon oxide) as a medium refractive index layer having a refractive index of about 1.50 to 1.85.

[0124] The optical adjustment layer may have, for example, the following structures: the three-layer structure of the first low refractive index layer, the high refractive index layer, and the second low refractive index layer from the metal reflective layer 11 side; the four-layer structure of the high refractive index layer, the first low refractive index layer, the high refractive index layer, and the second low refractive index layer from the metal reflective layer 11 side; the five-layer structure of the first low refractive index layer, the high refractive index layer, the medium refractive index layer, the high refractive index layer, and the second low refractive index layer from the metal reflective layer 11 side, etc.

[0125] Furthermore, the optical adjustment layer may be a laminate of six or more thin films.

[0126] <Other floors>

[0127] The optical laminate 1 according to the embodiment of the present invention may include other layers depending on the application in addition to the first base film 14 , the adhesive layer 15 , the second base film 10 , the metal reflective layer 11 , and the optical adjustment layer 13 described above.

[0128] Examples of the other layers include an adhesive layer, a protective layer, a hard coat layer, a barrier layer, an adhesion-facilitating layer, an antireflection layer, a light-extracting layer, an antiglare layer, and an infrared absorption layer.

[0129] For example, some oxides, such as niobium oxide, are reduced when irradiated with ultraviolet light in a state where they are laminated with a binder. In order to prevent the reduction, a layer composed of silicon oxide may be further laminated as a protective layer.

[0130] <Adhesive layer>

[0131] like Figure 3 As shown, the optical layered body 1 according to the embodiment of the present invention can be used as a concave mirror 100 by being laminated on a base 40 via an adhesive layer 12 , for example.

[0132] From the viewpoint of the adhesiveness of the optical layered body 1 to the substrate 40 , the adhesive layer 12 may be formed using, for example, any one of acrylic adhesives, polyester adhesives, and urethane adhesives alone or in combination of two or more thereof.

[0133] The adhesive layer 12 is preferably protected by a release liner until being attached to an adherend.

[0134] (Method for forming adhesive layer)

[0135] The adhesive layer 12 can be formed of an adhesive composition.

[0136] The adhesive layer can also be formed, for example, by applying an adhesive composition on a second substrate film and drying and removing the solvent. When applying the adhesive composition, one or more solvents can be appropriately added. The adhesive layer can also be formed, for example, by laminating the adhesive layer side of a laminate of an adhesive layer and a release liner to the second substrate film, wherein the adhesive layer is formed on the release liner by the adhesive composition. The adhesive layer can be formed by laminating the adhesive layer formed in a film shape on the release liner on the second substrate film while heating it.

[0137] From the viewpoint of the appearance when the optical laminate and the substrate are stacked, the thickness of the adhesive layer is preferably 5 μm or more, more preferably 10 μm or more, and further preferably 25 μm or more. In addition, from the viewpoint of suppressing the poor appearance caused by uneven film thickness, the thickness of the adhesive layer is preferably 100 μm or less, more preferably 75 μm or less, and further preferably 50 μm or less.

[0138] The thickness of the adhesive layer can be measured with a micrometer or the like.

[0139] Various methods can be used as a coating method for the adhesive composition. Specifically, for example, roll coating, lick roll coating, gravure coating, reverse coating, roll brushing, spray coating, dip roll coating, rod coating, blade coating, air knife coating, curtain coating, die lip coating, extrusion coating using a die coater, etc. can be cited.

[0140] The heating and drying temperature is preferably 30°C to 200°C, more preferably 40°C to 180°C, and further preferably 80°C to 160°C. By setting the heating temperature to the above range, an adhesive layer having excellent adhesive properties can be obtained. The drying time can be appropriately used for an appropriate time. The above drying time is preferably 5 seconds to 20 minutes, more preferably 30 seconds to 10 minutes, and further preferably 1 minute to 8 minutes.

[0141] Examples of the method for thermally bonding the adhesive layer include roll lamination and vacuum pressing.

[0142] The pressure during the pressure bonding by roll lamination is not particularly limited as long as lamination is performed, but is preferably 0.1 to 3 MPa, more preferably 0.2 to 1 MPa. The heating temperature is preferably 60 to 150°C, more preferably 80 to 120°C, for example.

[0143] The adhesive layer in the optical laminate may be protected by a release liner (separator).

[0144] For example, when the optical laminate is shipped, the adhesive layer is protected by the release liner. Afterwards, the release liner can be peeled off and laminated with a substrate to produce a concave mirror.

[0145] There are no particular restrictions on the release liner as long as it can protect the adhesive layer. Examples thereof include plastic films, porous materials such as paper, cloth, and nonwoven fabrics, nets, foam sheets, metal foils, and appropriate thin sheets such as laminates thereof. Plastic films are preferably used in view of excellent surface smoothness.

[0146] Examples of the plastic film include polyethylene film, polypropylene film, polybutylene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polybutylene terephthalate film, polyurethane film, and ethylene-vinyl acetate copolymer film.

[0147] The thickness of the release liner is usually 5 to 200 μm, preferably 5 to 100 μm. The release liner may be subjected to release and antifouling treatment using silicone, fluorine, long-chain alkyl or fatty acid amide release agents, silica powder, etc., or antistatic treatment such as coating, mixing, or vapor deposition. In particular, by appropriately subjecting the surface of the release liner to release treatment such as silicone treatment, long-chain alkyl treatment, or fluorine treatment, the release property relative to the adhesive layer can be further improved.

[0148] The optical layered body 1 according to the embodiment of the present invention is preferably in a film form. Specifically, the thickness of the optical layered body is preferably 6 μm to 250 μm, and more preferably 20 μm to 100 μm.

[0149] When the optical layered body is formed into a film, it can be attached to a substrate having a concave shape, so a concave mirror can be manufactured with good productivity.

[0150] [Manufacturing of optical laminate]

[0151] The method for producing the optical laminate according to the embodiment of the present invention is not particularly limited. Figure 2 In the case of the optical laminate 1 shown, a metal reflective layer 11 is formed on one side of a second substrate film 10, and a first low refractive index layer 13a, a high refractive index layer 13b, and a second low refractive index layer 13c are sequentially formed on the metal reflective layer 11 to produce a reflective film 20. In addition, an adhesive layer 15 is formed on one side of a first substrate film 14 to produce a protective film 30. Then, the surface of the reflective film 20 on the side of the second low refractive index layer 13c is bonded to the surface of the protective film 30 on the side of the adhesive layer 15, thereby producing the optical laminate 1.

[0152] The optical laminate may further include an adhesive layer. The adhesive layer 12 may be directly formed by applying a composition capable of forming the adhesive layer 12 on the other surface of the second base film or by laminating a separately formed adhesive layer 12 .

[0153] The formation method when forming the metal reflective layer 11, the first low refractive index layer 13a, the high refractive index layer 13b, and the second low refractive index layer 13c is not particularly limited, and for example, vacuum evaporation, sputtering, ion plating, etc. can be listed. From the aspect that the thickness can be strictly controlled even in a large area, sputtering is preferably used.

[0154] The adhesive layer 15 may be directly formed by applying a composition capable of forming the adhesive layer 15 on one side of the first base film, or may be formed by laminating a separately formed adhesive layer 15 .

[0155] The optical layered body according to the embodiment of the present invention can be used for a concave mirror.

[0156] Furthermore, the optical layered body according to the embodiment of the present invention can also be used for decoration of a member. For example, it can be attached to an adherend member and used. As the adherend member, for example, a member formed of glass or plastic can be used, but the invention is not limited thereto.

[0157] [concave mirror]

[0158] The concave mirror according to the embodiment of the present invention is a concave mirror comprising the above-mentioned optical layered body and a base having a concave shape, wherein the surface of the optical layered body on the reflective film side and the surface of the base having a concave shape on the concave side are laminated via an adhesive layer.

[0159] Figure 3 This is a schematic cross-sectional view of a concave mirror according to an embodiment of the present invention. Figure 3 In the concave mirror 100 shown, an optical laminate having a second substrate film 10, a metal reflective layer 11, an optical adjustment layer 13 (a first low refractive index layer 13a, a high refractive index layer 13b, and a second low refractive index layer 13c), an adhesive layer 15, and a first substrate film 14 is adhered to the concave side of a base 40 via an adhesive layer 12.

[0160] It should be noted that Figure 3 In the schematic cross-sectional view of the concave mirror in FIG. 1 , each layer is schematically shown as a planar layer. In fact, the base 40 has a concave shape with the surface on the a side being the concave side, and each layer stacked thereon also has a concave shape.

[0161] When a film-shaped optical layered body is used, the concave mirror according to the embodiment of the present invention can be bonded to a substrate and thus can be manufactured with good productivity.

[0162] <Material>

[0163] The material of the substrate is not particularly limited, and resin, glass, metal, etc. can be listed. From the perspective of being able to be used for the film embedding molding described later, resin is preferably used. As resin, polyester resins such as polyethylene terephthalate (PET), polybutylene terephthalate, and polyethylene naphthalate can be listed; (meth) acrylic resins such as polymethacrylate (acrylic resin and / or methacrylic resin); olefin resins such as polyethylene, polypropylene, and cycloolefin polymers (such as norbornene, cyclopentadiene); polycarbonate resins, polyethersulfone resins, polyarylate resins, melamine resins, polyamide resins, polyimide resins, cellulose resins, polystyrene resins, etc. These materials can be used alone or in combination of two or more. Among them, from the perspective of being able to form black and light-shielding properties, polycarbonate resins are preferred.

[0164] (Surface roughness Ra of protective film in concave mirror)

[0165] In the concave mirror of the embodiment of the present invention, from the viewpoint of improving the mirror surface, the surface roughness Ra of the adhesive layer side surface of the protective film is 180 nm or less, preferably 100 nm or less, more preferably 50 nm or less, and further preferably 30 nm or less.

[0166] Here, the surface roughness Ra of the protective film in the concave mirror according to the embodiment of the present invention is obtained by peeling the protective film from the concave mirror and measuring the arithmetic average surface roughness of the surface on the adhesive layer side of the peeled protective film.

[0167] It should be noted that in the concave mirror of the embodiment of the present invention, the protective film is used to protect the reflective film when the concave mirror is formed. In actual use, the protective film can be peeled off from the concave mirror and used, or it can be used without peeling off. It is preferred to peel off the protective film from the concave mirror and use it.

[0168] [Manufacturing of concave mirror]

[0169] The method for producing the concave mirror of the present embodiment is not particularly limited, and the concave mirror is preferably a concave mirror obtained by laminating the above-mentioned optical layered body and a base having a concave shape by film insert molding.

[0170] Furthermore, the concave mirror may be a concave mirror obtained by laminating the above-mentioned optical layered body and a base having a concave shape.

[0171] Next, a method for manufacturing a concave mirror is described.

[0172] <Film Insert Molding>

[0173] In the present embodiment, as a method for manufacturing a concave mirror 100, it is a method for manufacturing a concave mirror having the above-mentioned optical layered body 1 and a base 40 having a concave shape, preferably the following method: the base 40 having a concave shape is molded by film embedding molding, and the optical layered body 1 is stacked on the surface of the concave side of the base 40 having a concave shape via an adhesive layer.

[0174] Figures 4 to 6 It is an explanatory diagram for explaining the steps of manufacturing the concave mirror 100 by film insert molding.

[0175] The mold for insert molding the concave mirror 100 film includes a convex mold 51 and a concave mold 52 .

[0176] like Figure 4 As shown, the optical laminate 1 is arranged on the male mold 51 side. Figure 4 Not shown in the figure, for example, in the manufacture Figure 3In the case of the concave mirror 100 having the laminated structure shown, the optical laminate 1 may be arranged so that the surface of the optical laminate 1 on the adhesive layer 12 side faces the concave mold 52 side.

[0177] Next, the male mold 51 is pressed against the female mold 52 to seal the molding space 53. Figure 5 As shown, after the molten material resin 41 of the base is injected into the molding space 53 through the resin inflow path 54 , the molten material resin is solidified. Thus, the optical laminate 1 and the base 40 are laminated with the adhesive layer 12 interposed therebetween.

[0178] Next, the male mold 51 is pulled out and moved in a predetermined direction. The cured matrix material resin remains in the female mold 52. Figure 6 As shown, the solidified material resin is demolded from the concave mold 52 by an ejector pin (not shown) provided on the concave mold 52, and the unnecessary portion (flow path portion) is cut off. Thus, the concave mirror 100 is completed.

[0179] In the method for manufacturing the concave mirror 100 in the present embodiment described above, since the optical layered body 1 and the base 40 are integrally molded, the productivity of the concave mirror 100 can be improved.

[0180] The mold temperature during molding is preferably 200° C. or higher, more preferably 250° C. or higher, from the viewpoint of flowability and moldability of the molten material resin 41 , and preferably 300° C. or lower, more preferably 270° C. or lower, from the viewpoint of suppressing thermal deformation of the optical layered body.

[0181] As described above, the optical layered body is also exposed to high temperature during film embedding molding, but the optical layered body of this embodiment has a protective film whose surface roughness and thermal deformation are within a specified range. Therefore, the degradation of the surface shape of the reflective film caused by the protective film during the concave mirror processing can be suppressed, and a concave mirror with high mirror properties can be manufactured.

[0182] <Lamination molding>

[0183] The manufacturing method of the concave mirror 100 of the present embodiment is a manufacturing method of a concave mirror having the above-mentioned optical layered body 1 and a substrate 40 having a concave shape, and can be a method as follows: the optical layered body 1 is laminated on the concave surface of the substrate 40 having a concave shape via an adhesive layer by lamination.

[0184] The lamination may be vacuum lamination.

[0185] The vacuum lamination can be performed using a vacuum laminating device. Examples of commercially available vacuum laminating devices include Vacuum Pressing Device 3D Model manufactured by Mikado Technos Co., Ltd. and Vacuum Lamination Precision Single Sheet Laminating Machine manufactured by Climb Products Co., Ltd.

[0186] The degree of vacuum in the vacuum laminator is not particularly limited as long as lamination is performed, but is preferably 10 kPa or less, more preferably 5 kPa or less, and further preferably 1 kPa or less.

[0187] The pressure bonding by vacuum lamination may be performed while heating. The heating temperature is, for example, preferably 20 to 180°C, more preferably 20 to 150°C.

[0188] Furthermore, the lamination may be roll lamination.

[0189] Roll lamination can be performed, for example, using a curved surface robot laminating device manufactured by SANTEC.

[0190] The pressure during pressure bonding by roll lamination is not particularly limited as long as lamination is performed, but is preferably 0.1 to 3 MPa, and more preferably 0.2 to 1 MPa, for example.

[0191] The pressure bonding by roll lamination may be performed under heating, and the heating temperature is, for example, preferably 20 to 150°C, more preferably 60 to 100°C.

[0192] When a concave mirror is manufactured by lamination, at least a portion of the concave surface of the base 40 may be corona treated, and the optical layered body 1 may be laminated on the corona treated surface of the base 40 via the adhesive layer 12 by lamination.

[0193] [Application of optical laminate and concave mirror]

[0194] As the use of the optical laminate and concave mirror of the embodiment of the present invention, for example, there can be listed: vehicle structural parts, vehicle-mounted products such as head-up displays, housings of electronic devices, housings of household appliances, structural parts, mechanical parts, various automotive parts, electronic equipment parts, furniture, kitchen supplies and other home-oriented uses, medical equipment, parts of building materials, other structural parts, outer packaging parts, etc. More specifically, in vehicle relations, there can be listed: instrument panel, inter-seat storage box, door handles, door trims, shift levers, pedals, glove boxes, bumpers, engine hoods, fenders, trunks, doors, roofs, pillars, seats, steering wheels, ECU boxes, electrical parts, engine peripheral parts, drive system / gear peripheral parts, intake / exhaust system parts, cooling system parts, etc. More specifically, electronic devices and household appliances include refrigerators, washing machines, vacuum cleaners, microwave ovens, air conditioners, lighting equipment, electric water heaters, televisions, clocks, ventilating fans, projectors, speakers and other household appliances, personal computers, mobile phones, smart phones, digital cameras, tablet PCs, portable music players, portable game consoles, chargers, batteries and other electronic information devices.

[0195] Among the above, a concave mirror which can be used as a head-up display is particularly preferable.

[0196] [Example]

[0197] Hereinafter, the present invention will be described based on Examples, but the present invention is not limited thereto.

[0198] [Example 1]

[0199] [Production of reflective film]

[0200] <Second base film>

[0201] A 1.5 μm-thick ultraviolet curable resin layer (hard coat layer) was formed on a PET film 50-U483 (thickness 50 μm) manufactured by Toray Corporation as a second base film to obtain a second base film with a hard coat layer.

[0202] <Production of Metal Reflective Layer>

[0203] An Al target and the second base film with a hard coating layer were installed in a laboratory magnetron sputtering device to form a 44 nm thick aluminum layer (Al layer) as a metal reflective layer on the hard coating layer side surface of the second base film with a hard coating layer.

[0204] <Production of optical adjustment layer>

[0205] The second substrate film with a hard coating layer formed with an Al layer using a laboratory magnetron sputtering device was installed in the magnetron sputtering device, and a transparent oxide thin film was formed on the Al layer in the order of 67nm of silicon oxide (SiO2) (refractive index 1.46) as the first low refractive index layer, 53nm of niobium oxide (Nb2O5) (refractive index 2.32) as the high refractive index layer, and 40nm of silicon oxide (SiO2) (refractive index 1.46) as the second low refractive index layer to form an optical adjustment layer, thereby producing a reflective film. When forming the silicon oxide and niobium oxide thin films, a pure silicon target and a pure niobium target were used as targets, and oxygen was introduced in addition to argon gas to perform reactive sputtering, thereby obtaining transparent oxide thin films respectively.

[0206] [Production of protective film]

[0207] (Preparation of solvent-based acrylic polymer solution (CA-1))

[0208] Into a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen inlet tube, and a cooler, 100 parts by mass of butyl acrylate, 5 parts by mass of acrylic acid, 0.2 parts by mass of benzoyl peroxide as a polymerization initiator, and 200 parts by mass of ethyl acetate were added, and nitrogen was introduced while slowly stirring to maintain the liquid temperature in the flask at around 65° C. The polymerization reaction was carried out for about 6 hours to obtain a solvent-based acrylic polymer solution (CA-1) (concentration 30% by mass).

[0209] (Preparation of acrylic adhesive solution (CB-1))

[0210] A solvent-based acrylic polymer solution (CA-1) (concentration 30% by mass) was diluted to 20% by mass with ethyl acetate, and 6.0 parts by mass of an epoxy compound (TETRAD-C, manufactured by Mitsubishi Gas Chemical Co., Ltd.) was added per 100 parts by mass of the acrylic polymer solid content in the solution. The mixture was mixed and stirred at 25°C for about 1 minute to obtain an acrylic adhesive solution (CB-1).

[0211] (Manufacturing of Protective Film (C1))

[0212] A PET film "lumirror S10" (thickness 38 μm, manufactured by TORAY) as a first substrate film was subjected to corona treatment on one side, and an acrylic adhesive solution (CB-1) was applied to the corona-treated surface and dried at 80°C for 1 minute to form an adhesive layer with a thickness of 5 μm, thereby producing a protective film (C1).

[0213] [Production of optical laminate]

[0214] The surface of the reflective film on the optical adjustment layer side and the surface of the protective film (C1) on the pressure-sensitive adhesive layer side were bonded together.

[0215] Based on the above, thin layers of aluminum 44nm, silicon oxide 67nm, niobium oxide 53nm, and silicon oxide 40nm are formed in the order of one side of a PET film with a thickness of 51.5μm and a hard coating, and a film-like optical laminate 1 is further produced which is laminated with an adhesive layer of 5μm and a PET film with a thickness of 38μm.

[0216] [Production of concave mirror]

[0217] A crystalline copolyester resin "Vylon GM-920" (manufactured by Toyobo Co., Ltd.) was dissolved in toluene and applied by screen printing to the non-sputtered surface of the second substrate film of the optical laminate 1, and dried at 90°C for 1 minute to obtain a laminate having a 10 μm thick adhesive layer.

[0218] The obtained laminate was placed on the male mold side of a molding apparatus (NEX1000 manufactured by Nissei Plastic Industry Co., Ltd.) so that the first base film side was in contact with the male mold.

[0219] Next, the convex mold with the laminated body was pressed against the concave mold to seal the molding space in the molding device, and the mold temperature was raised to 90° C. A polycarbonate resin (L1225ZL manufactured by Teijin Limited) molten at 270° C. was injected from the resin inlet of the molding device to solidify the polycarbonate resin.

[0220] The concave mirror was taken out from the mold, wherein the optical laminate was laminated on the concave surface side of the polycarbonate substrate via the adhesive layer. The thickness of the substrate of the obtained concave mirror was 3 mm.

[0221] [Example 2]

[0222] An optical layered body and a concave mirror were produced in the same manner as in Example 1 except that the thickness of the pressure-sensitive adhesive layer of the protective film was changed to 21 μm.

[0223] [Example 3]

[0224] An optical layered body and a concave mirror were produced in the same manner as in Example 1 except that the thickness of the first base film was changed to 125 μm (“LUMIRROR #125-U48” manufactured by TORAY CORPORATION).

[0225] [Comparative Example 1]

[0226] An optical layered body and a concave mirror were produced in the same manner as in Example 1 except that the first substrate film was changed to a PP (polypropylene) film (FSA020M (thickness 30 μm)) manufactured by Futamura Chemical Co., Ltd.

[0227] [Comparative Example 2]

[0228] An optical layered body and a concave mirror were produced in the same manner as in Example 1 except that the first base film was changed to a PE (polyethylene) film (75-7H52 (thickness 75 μm)) manufactured by TORAY ADVANCED FILM CO., LTD.

[0229] <Arithmetic mean surface roughness Ra>

[0230] The protective films were peeled off from the optical laminates obtained in Examples and Comparative Examples.

[0231] The peeled protective film was fixed on a smooth table without bending, and the arithmetic mean surface roughness Ra of the adhesive layer side surface of the protective film of Examples and Comparative Examples was measured under the following conditions in accordance with JIS B0633 using an optical surface property measuring instrument ZYGO New View 7300 manufactured by ZYGO Corporation.

[0232] Measurement magnification: objective lens ×10, zoom ×1.

[0233] Measuring range: 720μm×480μm.

[0234] <Thermal deformation>

[0235] The protective films were peeled off from the optical laminates obtained in Examples and Comparative Examples.

[0236] The dimensional change behavior of the peeled protective film during heating was analyzed by TMA (Thermomechanical Analysis). The measurement conditions were set as sample width 4mm, load 20mN / 4mm, initial length 10mm, and the dimensional change rate of the protective film in the MD direction and TD direction after heating at 110°C for 1 hour was measured.

[0237] Regarding the dimensional change rate, two marks (wounds) were formed on the substrate surface of the peeled protective film in the MD direction and the TD direction with an interval of about 80 mm. The distance between the marks L0 before heating and the distance between the marks L after heating were measured by a two-dimensional length measuring machine to calculate the dimensional change rate (%).

[0238] <Mirror surface>

[0239] The protective films were peeled off from the concave mirrors obtained in Examples and Comparative Examples.

[0240] The appearance of the reflective film-side surface of the concave mirror from which the protective film was peeled was evaluated based on the following indices.

[0241] ◎: The reflected image is not deformed.

[0242] ○: The reflected image is hardly deformed.

[0243] △: The reflected image is distorted.

[0244] ×: The reflected image is significantly deformed.

[0245] The results are shown in Table 1 below.

[0246] [Table 1]

[0247]

[0248] As shown in Table 1, the optical layered body of this example can form a concave mirror with high mirror surface properties.

[0249] It should be noted that the Ra of the adhesive layer side surface of the protective film before lamination of the optical laminate used to manufacture the embodiments and comparative examples, and the Ra of the adhesive layer side surface of the protective film from which the protective film was peeled off from the concave mirror manufactured in the embodiments and comparative examples, were also measured in the same manner as above. The results are also shown in Table 2 below. In Table 2, "before lamination" is the measurement result of the protective film before lamination used in the manufacture of the optical laminate, "optical laminate" is the measurement result of the protective film after peeling off from the optical laminate, and "concave mirror" is the measurement result of the protective film after peeling off from the concave mirror.

[0250] [Table 2]

[0251]

[0252] The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims. Embodiments obtained by appropriately combining technical means disclosed in different embodiments are also included in the technical scope of the present invention.

[0253] Industrial Applicability

[0254] According to the present invention, it is possible to provide an optical layered body capable of forming a concave mirror with high mirror surface properties, a concave mirror using the optical layered body, and a method for producing a concave mirror.

[0255] While the present invention has been described in detail and with reference to specific embodiments, it will be apparent to one skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present invention.

[0256] This application is based on the Japanese patent application (Japanese Patent Application No. 2022-143871) filed on September 9, 2022, the contents of which are incorporated herein by reference.

[0257] Description of Reference Numerals

[0258] 1: optical laminate; 10: second substrate film; 11: metal reflective layer; 12: adhesive layer; 13: optical adjustment layer; 13a: first low refractive index layer; 13b: high refractive index layer; 13c: second low refractive index layer; 14: first substrate film; 15: adhesive layer; 20: reflective film; 30: protective film; 40: base; 41: material resin; 51: convex mold; 52: concave mold; 53: molding space; 54: resin inflow path; 100: concave mirror; a: concave side.

Claims

1. An optical laminate comprising a reflective film and a protective film on the reflective film, The protective film comprises a first base film and an adhesive layer on the first base film. The surface of the protective film on the side of the adhesive layer is bonded to the reflective film, The surface roughness Ra of the surface on the adhesive layer side of the protective film is 180 nm or less, The thermal deformation of the protective film at 110° C. is less than 1%.

2. The optical layered body according to claim 1, wherein: The reflective film has a metal reflective layer and an optical adjustment layer in sequence on the second substrate film, wherein the optical adjustment layer includes at least one high refractive index layer with a refractive index of 1.75 or more. The surface of the protective film on the side of the pressure-sensitive adhesive layer is bonded to the surface of the reflective film on the side of the optical adjustment layer.

3. A concave mirror comprising the optical layered body according to claim 1 or 2 and a substrate having a concave shape, The surface of the optical layered body on the side of the reflective film and the surface of the base having the concave surface shape on the side of the concave surface are laminated via an adhesive layer.

4. The concave mirror according to claim 3, wherein: The optical laminate and the base having a concave surface shape are laminated by film insert molding.

5. The concave mirror according to claim 3, wherein: The optical layered body and the base having the concave surface shape are stacked by lamination.

6. A method for manufacturing a concave mirror, wherein: The concave mirror comprises the optical layered body according to claim 1 or 2 and a base having a concave shape. The base having a concave surface shape is molded by film insert molding, and the optical layered body is laminated on the concave surface side of the base having a concave surface shape via an adhesive layer.

7. A method for manufacturing a concave mirror, wherein: The concave mirror comprises the optical layered body according to claim 1 or 2 and a base having a concave shape. The optical layered body is laminated on the concave surface of the base having the concave surface shape via the adhesive layer by lamination.

8. The method for manufacturing a concave mirror according to claim 7, wherein: The lamination is vacuum lamination.

9. The method for manufacturing a concave mirror according to claim 7, wherein: The lamination is roll lamination.

Images