Laminate, window film, and external light utilization type display body

Abstract

A laminate (window film 2) includes: a light diffusion control film 1 that has an internal structure in a film, the internal structure including a plurality of regions having a relatively high refractive index in a region having a relatively low refractive index; and ultraviolet absorption layers (adhesive layers 22a, 22b containing an ultraviolet absorber) located closer to an external light incident side than the light diffusion control film 1. The light diffusion control film 1 is obtained from a composition containing a high refractive index component and a low refractive index component having a refractive index lower than that of the high refractive index component. The low refractive index component is urethane acrylate having a structure derived from a hydroxyl group-containing acrylic monomer represented by the following general formula (I). The laminate is suppressed in liquefaction. (In the formula, R is a hydrogen atom, and n is an integer of 1 or more).

Description

Laminates, window films, and ambient light-utilizing displays

[0001] The present invention relates to a laminate, a window film, and an external light-utilizing display body, all equipped with a light diffusion control film that can diffuse or transmit incident light depending on the angle of incidence.

[0002] In recent years, light diffusion control films have been developed that can diffuse or transmit incident light depending on the angle of incidence. Such light diffusion control films are being considered for use as viewing angle control films to protect privacy when attached to window glass or touch panels of cash dispensers, and as light control films for reflective liquid crystal displays. Furthermore, the above-mentioned light diffusion control films are being considered for use in ambient light-utilizing displays, specifically signs and markers, which are created by printing characters or images on surfaces with light diffusion properties or specular reflective surfaces, or by laminating transparent or translucent films printed with characters or images onto these surfaces.

[0003] As an example of the light diffusion control film described above, there are films that have an internal structure in which multiple regions with relatively high refractive indices are located within a region with a relatively low refractive index. More specifically, there are light diffusion control films having a louver structure in which multiple plate-like regions with different refractive indices are alternately arranged along any one direction along the film surface, and light diffusion control films having a column structure in which multiple columnar objects with relatively high refractive indices are arranged in a forest-like manner within a region with a relatively low refractive index.

[0004] As an example of a light diffusion control film as described above, Patent Document 1 discloses a light diffusion control film obtained by curing a resin composition for light diffusion control films containing a predetermined urethane acrylate compound, a predetermined (meth)acrylic acid ester compound having an aromatic skeleton, and a predetermined photopolymerization initiator.

[0005] Patent No. 6414883

[0006] However, the light diffusion control film described in Patent Document 1 had the problem of liquefying after being used over time under predetermined conditions.

[0007] This invention has been made in view of the above circumstances, and aims to provide a laminate, a window film, and an external light-utilizing display body equipped with a light diffusion control film that suppresses liquefaction.

[0008] To achieve the above objective, firstly, the present invention provides a laminate for use in an environment irradiated with ambient light, comprising: a light diffusion control film having an internal structure in which a plurality of regions with relatively high refractive indices are contained within a region with a relatively low refractive index; and an ultraviolet absorption layer located on the ambient light incidence side of the light diffusion control film, wherein the light diffusion control film is obtained from a composition containing a high refractive index component and a low refractive index component having a refractive index lower than that of the high refractive index component, and the low refractive index component is a urethane acrylate having a structure derived from a hydroxyl group-containing acrylic monomer represented by the following general formula (I). The present invention provides a laminate characterized by the following: (wherein R is a hydrogen atom and n is an integer of 1 or more.)

[0009] In the above invention (Invention 1), the urethane acrylate has improved reactivity because its terminal ends are acrylates instead of methacrylates, and even if the ether bond is broken, decomposition into smaller molecules is suppressed. By using this urethane acrylate as a low refractive index component for manufacturing a light diffusion control film, even when the laminate is used for a long period of time in an environment irradiated with ambient light and the ether bond is broken, liquefaction of the light diffusion control film is suppressed.

[0010] In the above invention (Invention 1), it is preferable that the urethane acrylate is a compound formed from the hydroxyl group-containing acrylic monomer, a compound containing at least two isocyanate groups, and a polyalkylene glycol (Invention 2).

[0011] In the above inventions (Inventions 1 and 2), it is preferable that the weight-average molecular weight of the urethane acrylate is 3,000 to 20,000 (Invention 3).

[0012] In the above inventions (Inventions 1 to 3), it is preferable that the high refractive index component is a (meth)acrylic acid ester containing a plurality of aromatic rings (Invention 4).

[0013] In the above inventions (inventions 1 to 4), it is preferable that the light transmittance of the ultraviolet absorbing layer at a wavelength of 380 nm is 30% or less (invention 5).

[0014] In the above inventions (inventions 1 to 5), the laminate may be a window film (invention 6).

[0015] In the above invention (Invention 6), it is preferable that the light diffusion control film is provided with ultraviolet absorption layers on both sides (Invention 7).

[0016] In the above inventions (inventions 1 to 5), the laminate may be an ambient light-utilizing display body (invention 8).

[0017] In the above invention (Invention 8), the ambient light-utilizing display body may be a station name sign (Invention 9).

[0018] Secondly, the present invention relates to a window film having a structure in which a first transparent resin film, a first adhesive layer containing an ultraviolet absorber, a second transparent resin film, a light diffusion control film, a third transparent resin film, and a second adhesive layer containing an ultraviolet absorber are directly or indirectly laminated in that order, wherein the light diffusion control film is obtained from a composition containing a high refractive index component and a low refractive index component having a lower refractive index than the high refractive index component, and the low refractive index component is a urethane acrylate having a structure derived from a hydroxyl group-containing acrylic monomer represented by the following general formula (I). The invention provides a window film characterized by the following: (wherein R is a hydrogen atom and n is an integer of 1 or more.)

[0019] Thirdly, the present invention relates to an external light-utilizing display body having a structure in which a first transparent resin film, a first adhesive layer containing an ultraviolet absorber, a decorative layer, a second transparent resin film, a second adhesive layer containing an ultraviolet absorber, a light diffusion control film, a first adhesive layer, a reflective layer, a third transparent resin film, and a second adhesive layer are directly or indirectly laminated in that order, wherein the light diffusion control film is obtained from a composition containing a high refractive index component and a low refractive index component having a refractive index lower than that of the high refractive index component, and the low refractive index component is a urethane acrylate having a structure derived from a hydroxyl group-containing acrylic monomer represented by the following general formula (I). The present invention provides an external light-utilizing display device characterized by (wherein R is a hydrogen atom and n is an integer of 1 or more).

[0020] In the above invention (Invention 11), it is preferable to have a fourth transparent resin film between the second ultraviolet absorber-containing adhesive layer and the light diffusion control film (Invention 12).

[0021] In the above inventions (inventions 11 and 12), it is preferable to provide a fifth transparent resin film between the light diffusion control film and the first adhesive layer (invention 13).

[0022] Fourth, the present invention relates to an external light-utilizing display body having a structure in which a first transparent resin film, a first adhesive layer, a second transparent resin film, a light diffusion control film, a third transparent resin film, and a second adhesive layer are directly or indirectly laminated in that order, wherein the first adhesive layer is an adhesive layer containing an ultraviolet absorber, and the light diffusion control film is obtained from a composition containing a high refractive index component and a low refractive index component having a lower refractive index than the high refractive index component, wherein the low refractive index component is a urethane acrylate having a structure derived from a hydroxyl group-containing acrylic monomer represented by the following general formula (I). The present invention provides an external light-utilizing display device characterized by (wherein R is a hydrogen atom and n is an integer of 1 or more).

[0023] In the above invention (Invention 14), it is preferable that the second adhesive layer is an adhesive layer containing an ultraviolet absorber (Invention 15).

[0024] In the above inventions (inventions 14 and 15), it is preferable that the first transparent resin film has a hard coat layer (invention 16).

[0025] According to the laminate, window film, and ambient light-utilizing display body of the present invention, liquefaction of the light diffusion control film is suppressed.

[0026] This is a schematic perspective view of the internal structure (column structure) of a light diffusion control film according to one embodiment of the present invention. This is a schematic perspective view of the internal structure (louver structure) of a light diffusion control film according to another embodiment of the present invention. This is a cross-sectional view of a laminate (window film) according to one embodiment of the present invention. This is a cross-sectional view of a laminate (external light-utilizing display) according to another embodiment of the present invention.

[0027] Embodiments of the present invention will be described below. [Laminate] A laminate according to one embodiment of the present invention is used in an environment where ambient light is irradiated, and comprises a light diffusion control film and an ultraviolet absorption layer located on the ambient light incidence side of the light diffusion control film. The light diffusion control film has an internal structure in which a plurality of regions with relatively high refractive indices are contained within a region with a relatively low refractive index, and is obtained from a composition containing a high refractive index component and a low refractive index component having a lower refractive index than the high refractive index component. The above internal structure is preferably a regular internal structure, and details will be described later.

[0028] In the light diffusion control film of the laminate according to this embodiment, the low refractive index component is a urethane acrylate having a structure derived from a hydroxyl group-containing acrylic monomer represented by the following general formula (I). (In the formula, R is a hydrogen atom, and n is an integer greater than or equal to 1.)

[0029] In the present embodiment, by using the urethane acrylate as a low refractive index component for manufacturing the light diffusion control film, even when the laminate according to the present embodiment is used for a long period in an external light irradiation environment, the light diffusion control film is suppressed from being liquefied.

[0030] The liquefaction of the light diffusion control film mainly occurs when it is used for a long period in an external light irradiation environment due to the cleavage of the ether bond of the resin by the generation of active oxygen and radicals, resulting in a decrease in molecular weight. In the urethane acrylate in the present embodiment, the terminal is acrylate instead of methacrylate, so the reactivity is improved, and even when the ether bond is about to be cleaved, the decrease in molecular weight is suppressed, and the liquefaction is suppressed.

[0031] Although most of the ultraviolet rays contained in the external light are absorbed by the ultraviolet ray absorption layer, there is also a small amount of weak ultraviolet rays that pass through the ultraviolet ray absorption layer. The liquefaction of the light diffusion control film is considered to be caused by the long-term irradiation of this weak ultraviolet ray, which breaks a predetermined molecular chain in the light diffusion control film. The light diffusion control film in the present embodiment is further suppressed from having a predetermined molecular chain broken compared with the conventional light diffusion control film.

[0032] Here, the "external light" in this specification is the light incident on the object (here, the laminate) from the outside of the object, including direct sunlight, skylight, ground-reflected light, as well as light from various illuminations or devices, and also includes light transmitted through a light-transmitting member such as glass or plastic.

[0033] In the general formula (I), n is an integer of 1 or more, preferably 1 to 10, more preferably 1 to 5, particularly preferably 1 to 3, and most preferably 1 to 2.

[0034] 1. Components 1-1. Light Diffusion Control Film The light diffusion control film in the present embodiment is obtained from a composition (hereinafter referred to as "light diffusion control composition D") containing a high refractive index component and a low refractive index component having a refractive index lower than that of the high refractive index component. The light diffusion control film in the present embodiment is preferably obtained by curing the above light diffusion control composition D. In that case, the high refractive index component and the low refractive index component preferably each have one or two polymerizable functional groups. By using such a light diffusion control composition D, it becomes easier to favorably form a regular internal structure described later.

[0035] The light diffusion control composition D preferably contains a component having an ether bond, and the component having an ether bond is preferably polyether urethane acrylate. When the light diffusion control film is irradiated with ultraviolet rays for a long time, it is considered that the ether bond in the film component is cleaved and liquefaction is likely to occur. In the light diffusion control film in the present embodiment, by using a urethane acrylate having a structure derived from the above-described hydroxyl group-containing acrylic monomer as the low refractive index component, the occurrence of liquefaction is effectively suppressed.

[0036] As a material for forming the light diffusion control film in the present embodiment, from the perspective of SDGs, a material with a high biomass content may be used, a material that can be recycled or reused may be used, or a recycled or reused material may be used.

[0037] Hereinafter, the case where the light diffusion control composition D contains a high refractive index component and a low refractive index component having a refractive index lower than that of the high refractive index component, and the high refractive index component and the low refractive index component each have one or two polymerizable functional groups will be described, but the present invention is not limited thereto.

[0038] (1) Components (1-1) High refractive index components Preferred examples of high refractive index components include (meth)acrylic acid esters containing aromatic rings, and in particular, (meth)acrylic acid esters containing multiple aromatic rings are preferred. Examples of (meth)acrylic acid esters containing multiple aromatic rings include (meth)acrylic acid biphenyl, (meth)acrylic acid naphthyl, (meth)acrylic acid anthrasyl, (meth)acrylic acid benzylphenyl, (meth)acrylic acid biphenyloxyalkyl, (meth)acrylic acid naphthyloxyalkyl, (meth)acrylic acid anthrasyloxyalkyl, (meth)acrylic acid benzylphenyloxyalkyl, etc., and those in which some of these are substituted with halogens, alkyls, alkoxys, alkyl halides, etc. Among these, (meth)acrylic acid biphenyl is preferred from the viewpoint of easily forming a good regular internal structure, and specifically, o-phenylphenoxyethyl acrylate, o-phenylphenoxyethoxyethyl acrylate, etc. are preferred. In this specification, (meth)acrylic acid means both acrylic acid and methacrylic acid. The same applies to other similar terms.

[0039] The (weight-average) molecular weight of the high refractive index component is preferably 150 to 2500, particularly preferably 200 to 1500, and even more preferably 250 to 1000. This facilitates the formation of a light-diffusion controlled film having a desired regular internal structure. When the theoretical molecular weight of the high refractive index component can be determined based on its molecular structure, the (weight-average) molecular weight of the high refractive index component refers to that theoretical molecular weight (molecular weight, not the weight-average molecular weight). On the other hand, when the theoretical molecular weight of the high refractive index component is difficult to determine, for example, because it is a polymer component, the (weight-average) molecular weight of the high refractive index component refers to the weight-average molecular weight obtained as a standard polystyrene equivalent value measured by gel permeation chromatography (GPC). The method for measuring the weight-average molecular weight in this specification refers to the standard polystyrene equivalent value measured by the GPC method.

[0040] The refractive index of the high refractive index component is preferably 1.45 to 1.70, more preferably 1.50 to 1.65, particularly preferably 1.54 to 1.60, and even more preferably 1.56 to 1.59. This facilitates the formation of a light diffusion control film having a desired regular internal structure and light diffusion control ability. In this specification, the refractive index refers to the refractive index of a predetermined component before curing the light diffusion control composition D, and the refractive index is measured in accordance with JIS K0062:1992.

[0041] The content of the high refractive index component in the light diffusion control composition D is preferably 25 to 400 parts by mass, particularly preferably 40 to 300 parts by mass, and even more preferably 50 to 200 parts by mass, per 100 parts by mass of the low refractive index component. This ensures that the regular internal structure of the formed light diffusion control film contains regions derived from the high refractive index component and regions derived from the low refractive index component in a desired ratio. As a result, it becomes easier to form a light diffusion control film having a desired regular internal structure.

[0042] (1-2) Low refractive index component The low refractive index component in this embodiment is a urethane acrylate having a structure derived from a hydroxyl group-containing acrylic monomer represented by the general formula (I) described above (hereinafter sometimes referred to as "hydroxyl group-containing acrylic monomer (a)"). Preferably, the urethane acrylate is a compound (polyether urethane acrylate) formed from a hydroxyl group-containing acrylic monomer (a), a compound (b) containing at least two isocyanate groups, and a polyalkylene glycol (c).

[0043] Preferred examples of compound (b) containing at least two of the above-mentioned isocyanate groups include aromatic polyisocyanates such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, and 1,4-xylylene diisocyanate; aliphatic polyisocyanates such as hexamethylene diisocyanate; alicyclic polyisocyanates such as isophorone diisocyanate (IPDI) and hydrogenated diphenylmethane diisocyanate; biuret and isocyanurate forms thereof; and adducts (e.g., xylylene diisocyanate-based trifunctional adducts) obtained by reaction with low molecular weight active hydrogen-containing compounds such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, and castor oil. Among these, alicyclic polyisocyanates are preferred, alicyclic diisocyanates containing only two isocyanate groups are particularly preferred, and compounds containing two isocyanate groups via an aliphatic ring are even more preferred, with isophorone diisocyanate (IPDI) being particularly preferred.

[0044] Preferred examples of the above polyalkylene glycol (c) include polyethylene glycol, polypropylene glycol, polybutylene glycol, polyhexylene glycol, and the like, with polypropylene glycol being the most preferred.

[0045] The weight-average molecular weight of polyalkylene glycol (c) is preferably 1,000 to 20,000, particularly preferably 1,300 to 12,000, even more preferably 1,600 to 7,000, and most preferably 1,800 to 4,000.

[0046] The synthesis of urethane acrylate using the above components (a) to (c) can be carried out according to conventional methods. In this case, from the viewpoint of efficiently synthesizing urethane acrylate, the mixing ratio of components (a) to (c) is preferably such that component (a):component (b):component (c) = 1 to 5:1 to 5:1 in molar ratio, and particularly preferably 1 to 3:1 to 3:1.

[0047] The weight-average molecular weight of the low refractive index component (urethane acrylate) is preferably 1,000 to 20,000, more preferably 1,250 to 16,000, particularly preferably 1,500 to 12,000, even more preferably 1,700 to 8,000, and most preferably 1,900 to 4,000. This facilitates the formation of a light-diffusion controlled film having a desired regular internal structure.

[0048] The refractive index of the low refractive index component is preferably 1.30 to 1.59, more preferably 1.40 to 1.50, particularly preferably 1.44 to 1.49, and even more preferably 1.46 to 1.48. This facilitates the formation of a light diffusion control film having a desired regular internal structure and light diffusion control ability.

[0049] (1-3) Photopolymerization initiator The light diffusion control composition D may also preferably contain a photopolymerization initiator. This makes it easier to efficiently form a light diffusion control film having a desired regular internal structure.

[0050] Examples of photopolymerization initiators include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2- Examples include propyl ketone, benzophenone, p-phenylbenzophenone, 4,4-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyldimethyl ketal, acetophenone dimethyl ketal, p-dimethylamine benzoate, oligo[2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propane], etc. These may be used individually or in combination of two or more.

[0051] When a photopolymerization initiator is used, the amount of the photopolymerization initiator in the light diffusion control composition D is preferably 0.2 to 20 parts by mass, particularly preferably 0.5 to 18 parts by mass, even more preferably 1 to 15 parts by mass, and most preferably 2 to 12 parts by mass, based on 100 parts by mass of the total amount of the high refractive index component and the low refractive index component. This makes it easier to efficiently form a light diffusion control film.

[0052] (1-4) The polyfunctional monomer light diffusion control composition D may also preferably contain a polyfunctional monomer. This is presumed to prevent fragmentation by holding the ether bond of the urethane acrylate together with the polyfunctional monomer-derived component, thereby more effectively suppressing liquefaction. Note that the above-mentioned polyfunctional monomer is not included in the high refractive index component and low refractive index component mentioned above.

[0053] As the polyfunctional monomer, polyfunctional acrylate monomers are preferred. From the viewpoint of suppressing the liquefaction of the light diffusion control film, polyfunctional acrylate monomers having three or more polymerizable functional groups are preferred, polyfunctional acrylate monomers having four or more polymerizable functional groups are particularly preferred, polyfunctional acrylate monomers having five or more polymerizable functional groups are even more preferred, and among these, polyfunctional acrylate monomers having six or more polymerizable functional groups are particularly preferred. On the other hand, from the viewpoint of preventing film warping during manufacturing, polyfunctional acrylate monomers having 30 or fewer polymerizable functional groups are preferred, polyfunctional acrylate monomers having 15 or fewer polymerizable functional groups are more preferred, and polyfunctional acrylate monomers having 8 or fewer polymerizable functional groups are particularly preferred.

[0054] Furthermore, from the viewpoint of compatibility with the aforementioned high refractive index components and low refractive index components, polyfunctional acrylate monomers with a molecular weight of less than 1000 are preferred.

[0055] Specifically, examples of polyfunctional acrylate monomers include trimethylolpropane tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, propionic acid-modified dipentaerythritol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, ethoxylated isocyanurate tri(meth)acrylate, propylene oxide-modified trimethylolpropane tri(meth)acrylate, and tris-(2-(meth)acryloxyethyl)iso Examples include trifunctional types such as cyanurate and ε-caprolactone-modified tris-(2-(meth)acryloxyethyl) isocyanurate; tetrafunctional types such as diglycerin tetra(meth)acrylate and pentaerythritol tetra(meth)acrylate; pentafunctional types such as propionic acid-modified dipentaerythritol penta(meth)acrylate; and hexafunctional types such as dipentaerythritol hexa(meth)acrylate and caprolactone-modified dipentaerythritol hexa(meth)acrylate. Among the above, acrylate monomers tend to have excellent resistance to liquefaction, and methacrylate monomers tend to have excellent light diffusion properties. These may be used individually or in combination of two or more types.

[0056] When using polyfunctional monomers, the content of the polyfunctional monomer in the light diffusion control composition D is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 15 parts by mass, particularly preferably 1 to 10 parts by mass, and even more preferably 2 to 5 parts by mass, based on 100 parts by mass of the total amount of high refractive index components and low refractive index components. This makes it easier to exhibit the effects described above.

[0057] (1-5) The hindered amine compound light diffusion control composition D may also preferably contain a hindered amine compound. By containing a hindered amine compound, the liquefaction of the light diffusion control film is more effectively suppressed even when the laminate according to this embodiment is used over time in an ambient light irradiation environment.

[0058] The hindered amine compound is preferably a low-basic hindered amine compound having a carbonate skeleton (hereinafter sometimes referred to as "hindered amine compound CL"). Even when ultraviolet light is irradiated onto the light diffusion control film for a long period of time and reactive oxygen species and radicals are generated, the hindered amine skeleton of the hindered amine compound CL can capture the reactive oxygen species and radicals, and the carbonate skeleton can suppress the cleavage of ether bonds. Furthermore, because the hindered amine compound CL is low-basic, it is not deactivated by acid. Due to these actions, the hindered amine compound CL can continuously capture the generated reactive oxygen species and radicals, and can more effectively suppress liquefaction of the laminate due to prolonged use.

[0059] Here, a hindered amine refers to an amine having bulky substituents on both sides of the amino group. Furthermore, "low basicity" in this specification means having relatively low basicity and is distinguished from ordinary "basicity." Specifically, it means that the base dissociation constant (pKb) in water at 1 atmosphere and 25°C is preferably 6 or higher, more preferably 8 or higher, particularly preferably 10 or higher, and even more preferably 11 or higher.

[0060] In this embodiment, the hindered amine compound CL is given by the following general formula (II) It is preferable that the compound contains at least one skeleton consisting of the following.

[0061] The hindered amine compound CL having the above structure exhibits excellent suppression of liquefaction in light diffusion control films. Furthermore, the hindered amine compound CL in this embodiment is N-O-R １ Having a skeletal structure results in good low basicity, and the aforementioned effects are further enhanced. １ Not the skeleton, but the N-alkyl group skeleton, especially N-CH ３ Hindered amine compounds with a skeletal structure exhibit basic properties.

[0062] In this embodiment, the hindered amine compound CL is R in the above general formula (II). １is preferably an alkyl group. The number of carbon atoms of the alkyl group is preferably 1 to 30, more preferably 3 to 25, particularly preferably 7 to 18, and even more preferably 9 to 13. R １ By being an alkyl group, it exhibits preferable low basicity, and by the number of carbon atoms of the alkyl group being in the above range, it exhibits more preferable low basicity.

[0063] The hindered amine compound CL in the present embodiment preferably has one or more skeletons composed of the above general formula (II), more preferably 2 to 10, particularly preferably 2 to 7, and even more preferably 2 to 4, and most preferably 2. The skeleton composed of the above general formula (II) may be present at the terminal of the hindered amine compound, may be present in the side chain, or may be present at the terminal and in the side chain.

[0064] When the hindered amine compound has two or more skeletons composed of the above general formula (II), each R １ may be the same or different.

[0065] The hindered amine compound CL in the present embodiment has a carbonate skeleton (—O—C(═O)—O—) at any position, but it is preferable that the oxygen atom at the terminal of the carbonate skeleton is bonded to the carbon atom at the 4th position in the skeleton composed of the above general formula (I). By having a carbonate skeleton at this position, the hindered amine compound CL becomes excellent in the effect of suppressing the liquefaction of the light diffusion control film.

[0066] As the hindered amine compound CL in the present embodiment, the following structural formula (A) is particularly preferably a compound represented by.

[0067] In the compound represented by the above structural formula (A), R １ is the same as R １ in the skeleton composed of the above general formula (II). The two Rs in the above structural formula (A) １They may be the same or different, but it is preferable that they be the same.

[0068] When using a hindered amine compound, the content of the hindered amine compound in the light diffusion control composition D is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 15 parts by mass, particularly preferably 0.5 to 10 parts by mass, and even more preferably 1 to 5 parts by mass, based on 100 parts by mass of the total amount of the high refractive index component and the low refractive index component. This results in a superior liquefaction suppression effect.

[0069] (1-6) Antioxidant light diffusion control composition D may also preferably contain an antioxidant. This makes it possible to more effectively suppress liquefaction due to the use of the laminate over time.

[0070] As an antioxidant, any of the conventionally known hindered phenol antioxidants, amine antioxidants, sulfur antioxidants, phosphorus antioxidants, quinone antioxidants, etc., can be appropriately selected and used, with hindered phenol antioxidants being particularly preferred.

[0071] Examples of hindered phenol antioxidants include triethylene glycol-bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate], pentaerythrityl-tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 2,2-thio-diethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], and n-octadecyl-3-(4'-hydroxy-3',5'-di-t-butylphenyl)propionate. These may be used individually or in combination of two or more.

[0072] When an antioxidant is used, the amount of antioxidant in the light diffusion control composition D is preferably 0.001 to 1 part by mass, more preferably 0.005 to 0.5 parts by mass, particularly preferably 0.01 to 0.2 parts by mass, and even more preferably 0.04 to 0.1 parts by mass, based on 100 parts by mass of the total amount of the high refractive index component and the low refractive index component. This results in a superior liquefaction suppression effect.

[0073] (1-7) The UV absorber light diffusion control composition D may also preferably contain a UV absorber. This will result in a better liquefaction suppression effect of the light diffusion control film.

[0074] Examples of UV absorbers include benzophenone compounds, benzotriazole compounds, triazine compounds, cyanoacrylate compounds, and salicylic acid ester compounds. One type may be used alone, or two or more types may be used in combination. Among these, benzophenone compounds, benzotriazole compounds, or triazine compounds are preferred, and benzotriazole compounds are particularly preferred. These compounds have good compatibility with the aforementioned high refractive index and low refractive index components, and also have a low degree of discoloration.

[0075] Examples of preferred benzophenone compounds include 2,2-dihydroxy-4-methoxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid hydrate, and 2-hydroxy-4-n-octyloxybenzophenone. Examples of preferred benzotriazole compounds include 2-(2-hydroxy-5-t-butylphenyl)-2H-benzotriazole, octyl-3-[3-t-butyl-4-hydroxy-5-(5-chloro-2H-benzotriazole-2-yl]phenyl]propionate, 2-ethylhexyl-3-[3-t-butyl-4-hydroxy-5-(5-chloro-2H-benzotriazole-2-yl]phenyl]propionate, and benzenepropanoate-3-(2H-benzotriazole-2-yl)-5-(1,1-dimethylethyl)-4-hydroxyalkyl ester. Examples of preferred triazine compounds include 2,4-bis[2-hydroxy-4-butoxyphenyl]-6-(2,4-dibutoxyphenyl)-1,3-5-triazine and 2-[4,6-di(2,4-xylyl)-1,3,5-triazine-2-yl]-5-octyloxyphenol. These may be used individually or in combination of two or more.

[0076] When using an ultraviolet absorber, the amount of ultraviolet absorber in the light diffusion control composition D is preferably 0.001 to 2 parts by mass, more preferably 0.005 to 1 part by mass, particularly preferably 0.01 to 0.5 parts by mass, and even more preferably 0.05 to 0.1 parts by mass, based on 100 parts by mass of the total amount of the high refractive index component and the low refractive index component. This results in a superior liquefaction suppression effect.

[0077] (1-8) Other Components The light diffusion control composition D may contain other additives in addition to the components described above. Examples of other additives include antistatic agents, polymerization accelerators, polymerization inhibitors, infrared absorbers, plasticizers, diluent solvents, and leveling agents.

[0078] (2) Preparation of the light diffusion control composition The light diffusion control composition D can be prepared by uniformly mixing the high refractive index component and the low refractive index component described above, as well as other additives such as a photopolymerization initiator if desired.

[0079] During the above mixing, the mixture may be heated to a temperature of 40 to 90°C while stirring to obtain a uniform light diffusion control composition D. Alternatively, a diluent solvent may be added and mixed so that the resulting light diffusion control composition D has a desired viscosity.

[0080] (3) Internal structure of the light diffusion control film The internal structure of the light diffusion control film in this embodiment has multiple regions with relatively high refractive indices within a region with a relatively low refractive index, thereby allowing incident light to be diffused or transmitted depending on the angle of incidence.

[0081] In this embodiment, the internal structure of the light diffusion control film is preferably a regular internal structure. Specifically, it is preferable that the internal structure is a regular structure in which multiple regions with relatively high refractive indices extend for a predetermined length in the film thickness direction within a region with a relatively low refractive index. Such a regular internal structure is distinguished from a phase separation structure in which one phase exists in the other phase without clear regularity, and from a sea-island structure in which a nearly spherical island component exists within a sea component, in that the regions with relatively high refractive indices extend in the film thickness direction.

[0082] One example of the above-mentioned regular internal structure is a column structure in which multiple columnar objects with relatively high refractive indices are arranged in a region with a relatively low refractive index in the direction of the film thickness. Another example is a louver structure in which multiple plate-like regions with different refractive indices are arranged alternately in any one direction along the film surface.

[0083] (3-1) Column Structure Figure 1 is a schematic perspective view showing the above column structure. As shown in Figure 1, in the column structure 11A, multiple columnar objects 111 with a relatively high refractive index are arranged in a row in the thickness direction, and the area around them is filled with a region 112 with a relatively low refractive index. In Figure 1, the columnar objects 111 are depicted as being present throughout the entire thickness direction of the column structure 11A, but it is possible that there are no columnar objects 111 at least at one of the upper end and lower end of the column structure 11A in the thickness direction.

[0084] When light is incident on a light diffusion control film having such a column structure 11A, if it falls within a predetermined incident angle range, it is emitted from the light diffusion control film while strongly diffusing with a predetermined opening angle. On the other hand, if the incident light is incident at an angle outside the above incident angle range, it is transmitted without diffusion, or emitted with weaker diffusion than in the case of incident light within the incident angle range. The diffused light generated by the column structure 11A will have a circular or nearly circular shape (elliptical shape, etc.) that spreads in all directions when the contrast agent is placed parallel to the surface of the light diffusion control film. On the other hand, in the case of weak diffusion due to incident light outside the above incident angle range, the diffused light will be crescent-shaped.

[0085] In the column structure 11A, it is preferable that the difference between the refractive index of the columnar material 111, which has a relatively high refractive index, and the refractive index of the region 112, which has a relatively low refractive index, is 0.01 to 0.3.

[0086] Preferably, the columnar object 111 described above has a structure in which its diameter expands from one side of the light diffusion control film to the other side. Compared to a columnar object whose diameter does not change significantly from one side to the other side, a columnar object 111 with such a structure makes it easier to change the direction of light propagation parallel to the axis of the columnar object, thereby enabling the light diffusion control film to effectively diffuse light.

[0087] Furthermore, the maximum diameter of the cross-section when the columnar object 111 is cut by a plane horizontal to the axial direction is preferably 0.1 to 10 μm. The cross-sectional shape when the columnar object 111 is cut by a plane perpendicular to the axial direction is not particularly limited, but it is preferably a circle, ellipse, polygon, or irregular shape.

[0088] In the column structure 11A, the distance between adjacent columnar objects 111 is preferably 0.1 to 10 μm.

[0089] Furthermore, in the column structure 11A, the columnar objects 111 may be arranged horizontally with respect to the thickness direction of the light diffusion control film, or they may be arranged at a certain angle of inclination. When arranged at a certain angle of inclination, the angle of inclination, that is, the acute angle between the axis of the columnar object 111 of the column structure 11A and the normal to the surface of the light diffusion control film, is preferably 1 to 50°.

[0090] Furthermore, the dimensions and predetermined angles related to the regular internal structure of the column structure 11A can be measured by observing the cross-section of the column structure 11A using an optical digital microscope.

[0091] (3-2) Louver Structure Figure 2 is a schematic perspective view showing the above-described louver structure. As shown in Figure 2, in the louver structure 11B, plate-like regions 113 with relatively high refractive indices are alternately arranged in one direction along the film surface, and regions 114 with relatively low refractive indices fill the spaces between them. In Figure 2, the plate-like regions 113 are depicted as existing throughout the entire thickness direction of the louver structure 11B, but it is possible that the plate-like regions 113 are not present at at least one of the upper end and lower end in the thickness direction of the louver structure 11B.

[0092] Light incident on a light diffusion control film having such a louver structure 11B will either be emitted from the light diffusion control film while diffusing, or will be transmitted without diffusing, depending on the angle of incidence. Furthermore, a light diffusion control film having a louver structure 11B has the property of easily diffusing in a direction perpendicular to the arrangement direction of the plate-like regions 113.

[0093] In the louver structure 11B, it is preferable that the difference between the refractive index of the plate-like region 113, which has a relatively high refractive index, and the refractive index of the region 114, which has a relatively low refractive index, is 0.01 to 0.3.

[0094] In the louver structure 11B, the thickness (width in the arrangement direction) of each plate-like region 113 is preferably 0.1 to 10 μm.

[0095] In the louver structure 11B, the plate-like regions 113 may be inclined along their arrangement direction, or they may not be inclined and may be arranged to coincide with the normal direction of the film. When they are inclined along the arrangement direction, the inclination angle, that is, the acute angle between one side of the plate-like region 113 and the normal of the light diffusion control film, is preferably 1 to 60°.

[0096] Furthermore, the dimensions and predetermined angles related to the internal structure of the louver structure 11B can be measured by observing the cross-section of the louver structure 11B using an optical digital microscope.

[0097] (3-3) Other Internal Structures The internal structure of the light diffusion control film in this embodiment may have structures other than the column structure 11A and louver structure 11B described above. For example, the light diffusion control film may have an internal structure in which the columnar objects 111 in the column structure 11A described above are bent in the middle of the thickness direction of the light diffusion control film. Alternatively, the light diffusion control film may have an internal structure in which the plate-like region 113 in the louver structure 11B described above is bent in the middle of the thickness direction of the light diffusion control film. Furthermore, the internal structure of the light diffusion control film in this embodiment may have two or more regions of columnar objects 111 or plate-like regions 113 in the thickness direction of the light diffusion control film, each having a different inclination angle, a different bending angle, or the presence or absence of bending. Alternatively, the light diffusion control film in this embodiment may have an internal structure formed by laminating the column structure 11A and the louver structure 11B, or the bent structures described above, in any combination.

[0098] (3-4) Ratio of internal structure in the thickness direction of the light diffusion control film As described above, the light diffusion control film in this embodiment preferably has an internal structure in which multiple regions with relatively high refractive indices are extended in the thickness direction within a region with a relatively low refractive index. Here, the ratio of the internal structure extending in the thickness direction is preferably 10% or more of the thickness of the light diffusion control film, more preferably 30% or more, particularly preferably 50% or more, and even more preferably 70% or more, from the viewpoint of making light diffusion more efficient. There is no upper limit, and the internal structure may be formed in the entire thickness direction, i.e., 100%.

[0099] (4) Physical properties of the light diffusion control film (4-1) Thickness The thickness of the light diffusion control film in this embodiment is preferably 20 to 700 μm, particularly preferably 40 to 400 μm, and even more preferably 60 to 200 μm. The lower limit of the thickness of the light diffusion control film is set as above, making it easier to achieve the desired light diffusion control performance. In addition, the upper limit of the thickness of the light diffusion control film is set as above, making it easier to suppress the occurrence of dents and crushing.

[0100] (4-2) When the internal structure of the light diffusion control film is the column structure 11A described above or a modified structure thereof, it is preferable that the angular range of incident angles that show a haze value greater than or equal to the threshold (the range of incident angles that show a haze value greater than or equal to the threshold) is 5 to 100°, with 90% of the maximum haze value measured when light is irradiated onto one surface of the diffusion film at an incident angle of -70° to 70°, with the normal direction of the surface being 0°.

[0101] Furthermore, when the internal structure of the light diffusion control film is the louver structure 11B described above or a modified structure thereof, the threshold is set to 60% of the maximum haze value measured when light is irradiated onto one surface of the diffusion film at an incident angle of -70° to 70°, with the normal direction of the surface being 0°. The angular range of incident angles that show a haze value above this threshold (variable haze angle range) is preferably 1° or more, more preferably 4° or more, particularly preferably 8° or more, and even more preferably 10° or more. This results in a wider angular range of incident light in which good light diffusion control performance can be achieved. The upper limit of the above variable haze angle range is not particularly limited and may be, for example, 120° or less, particularly 110° or less, and even 100° or less.

[0102] The details of the measurement method for the above-mentioned range of variable angle haze are as described in the test examples below.

[0103] (5) Method for manufacturing a light diffusion control film The method for manufacturing the light diffusion control film in this embodiment is not particularly limited and can be formed by conventionally known methods. For example, the above-mentioned composition for light diffusion control films, preferably light diffusion control composition D, is applied to one side of a process sheet to form a coating film. A light diffusion control film can be formed by curing the coating film by irradiating it with active energy rays. Alternatively, one side of a release sheet (especially the release side) may be bonded to the side of the coating film opposite to the process sheet before or after the irradiation with active energy rays, and the coating film may be cured by irradiating it with active energy rays through the process sheet or release sheet.

[0104] Examples of the above coating methods include knife coating, roll coating, bar coating, blade coating, die coating, and gravure coating. Furthermore, the light diffusion control composition D may be diluted with a solvent as needed.

[0105] The above-mentioned active energy rays refer to electromagnetic waves or charged particle beams that possess energy quanta, and specifically include ultraviolet rays and electron beams. Among active energy rays, ultraviolet rays are particularly preferred because they are easy to handle.

[0106] The irradiation of the coating film with active energy rays is carried out in different manners depending on the internal structure to be formed. For example, when forming the column structure 11A described above, the coating film is irradiated with parallel light that has a high degree of parallelism. Here, parallel light means light that is substantially parallel and does not spread out regardless of the direction from which it is viewed. Such parallel light can be prepared using known means such as lenses or light-shielding members. When irradiating, it is preferable to irradiate the laminate of the coating film and the process sheet in its longitudinal direction using a conveyor or the like while irradiating with the parallel light. The inclination angle of the columnar object 111 formed in the column structure 11A can also be adjusted by adjusting the irradiation angle of the parallel light.

[0107] When forming the column structure 11A using ultraviolet light as the active energy ray, the irradiation conditions are such that the peak illuminance on the coating surface is 0.1 to 10 mW / cm². ２ It is preferable to do so. Note that the peak illuminance referred to here means the measurement value at the point where the active energy rays irradiated onto the coating surface show their maximum value. Furthermore, the integrated light amount on the coating surface should be 5 to 200 mJ / cm². ２ It is preferable to do so.

[0108] Furthermore, when ultraviolet light is used as the active energy ray to form the column structure 11A, it is preferable that the relative movement speed of the light source of the active energy ray with respect to the laminate be 0.1 to 10 m / min.

[0109] On the other hand, when forming the aforementioned louver structure 11B, a linear light source is used as the light source for the active energy rays, and a band-shaped (almost linear) light is irradiated onto the laminate surface randomly in the width direction (TD direction) and substantially parallel in the flow direction (MD direction). The inclination angle of the plate-shaped region 113 formed within the louver structure 11B can also be adjusted by adjusting the irradiation angle of the above light.

[0110] When using ultraviolet light as the active energy ray to form the louver structure 11B, the irradiation conditions are such that the peak illuminance on the coating surface is 0.1 to 50 mW / cm². ２ It is preferable to do so. Furthermore, the integrated light intensity on the surface of the coating film should be 5 to 300 mJ / cm². ２ It is preferable that this be done. Furthermore, it is preferable that the relative movement speed of the light source of the active energy rays with respect to the laminate be 0.1 to 10 m / min.

[0111] Furthermore, from the viewpoint of ensuring more reliable curing, it is also preferable to irradiate the surface with normal active energy rays (active energy rays that have not been converted into parallel or band-shaped light, scattered light) after curing using parallel or band-shaped light as described above. In this case, from the viewpoint of uniform curing, a release sheet may be laminated onto the surface of the coating film.

[0112] 1-2. Ultraviolet Absorption Layer In this embodiment, the ultraviolet absorption layer is located on the side of the light incident side of the light diffusion control film in the laminate according to this embodiment. As a result, even when the laminate according to this embodiment is used for a long period of time in an environment irradiated with ambient light, the liquefaction of the light diffusion control film is more effectively suppressed.

[0113] The light transmittance of the ultraviolet absorption layer at a wavelength of 380 nm is preferably 30% or less, more preferably 10% or less, particularly preferably 1% or less, and even more preferably 0.1% or less. On the other hand, there is no particular restriction on the lower limit of this light transmittance, and it is preferably 0%. The light transmittance of the ultraviolet absorption layer at a wavelength of 380 nm is preferably compatible with the high transmittance in the visible light region described later. When the light transmittance of the ultraviolet absorption layer at a wavelength of 380 nm is within the above range, the light diffusion control film of the present invention is more easily protected from liquefaction over time in an ambient light irradiation environment. In addition, yellowing of the light diffusion control film can be effectively suppressed, and other components of the laminate can be protected from ultraviolet rays.

[0114] In this embodiment, the ultraviolet absorbing layer preferably has high transmittance of light in the visible light region. From this viewpoint, the light transmittance of the ultraviolet absorbing layer at a wavelength of 480 nm is preferably 60% or more, more preferably 70% or more, particularly preferably 80% or more, even more preferably 86% or more, and most preferably 90% or more. Similarly, from the same viewpoint, the light transmittance of the ultraviolet absorbing layer at a wavelength of 580 nm is preferably 60% or more, more preferably 70% or more, particularly preferably 80% or more, even more preferably 86% or more, and most preferably 90% or more. On the other hand, there are no particular restrictions on the upper limits of the light transmittance of the ultraviolet absorbing layer at a wavelength of 480 nm and the upper limits of the light transmittance at a wavelength of 580 nm, but it is preferably 100%. Furthermore, from the viewpoint of achieving compatibility with low transmittance in the ultraviolet light region, it is preferably 99% or less, and most preferably 98% or less.

[0115] The ultraviolet absorbing layer may be an adhesive layer containing an ultraviolet absorber, or a plastic film containing an ultraviolet absorber. Alternatively, it may be a combination of these, or a combination with other layers that do not contain an ultraviolet absorber. Furthermore, from the perspective of SDGs, the materials constituting the ultraviolet absorbing layer may be materials with a high biomass content, materials that are recyclable or reusable, or recycled or reused materials.

[0116] When the UV-absorbing layer is an adhesive layer containing a UV absorber, the type of adhesive constituting the adhesive layer is not particularly limited, and conventionally known adhesives can be used. For example, acrylic adhesives, silicone adhesives, urethane adhesives, rubber adhesives, etc., can be used as the adhesive, and among these, acrylic adhesives are preferred because they easily achieve good adhesion and transparency. The type of plastic used as the plastic film containing the UV absorber is also not particularly limited, and conventionally known plastics can be used.

[0117] The ultraviolet absorber in the ultraviolet absorption layer is not particularly limited, and the same type of ultraviolet absorber that can be contained in the aforementioned light diffusion control composition D can be used.

[0118] The thickness of the UV-absorbing layer can be appropriately selected depending on the type and material of the UV-absorbing layer. The thickness of the UV-absorbing layer when it is an adhesive layer containing a UV absorber is as described below.

[0119] 2. Applications The laminate according to this embodiment can be used in various applications where control of light diffusion is required in an ambient light environment. Examples include viewing angle control films that are attached to window glass, cash dispenser displays, computer monitors, smartphone displays, etc., to protect privacy; light control films used in reflective liquid crystal displays, etc.; and ambient light-utilizing displays such as signs and markers. Among the above, it can be suitably used in window films attached to window glass, etc., for the purpose of controlling the viewing angle, and in ambient light-utilizing displays.

[0120] When the laminate according to this embodiment is used as a window film attached to a windowpane, it is also preferable to have ultraviolet absorption layers on both sides of the light diffusion control film. This allows for the absorption of both ultraviolet rays from sunlight and ultraviolet rays from indoor lighting, effectively suppressing yellowing of the light diffusion control film and protecting desired components from ultraviolet rays. However, even with the above configuration, conventional light diffusion control films liquefy over time.

[0121] 3. Specific Examples of Laminates Below, specific examples of laminates according to this embodiment will be described using a window film as a viewing angle control film and an ambient light-utilizing display (for example, a station name sign), but the laminates according to the present invention are not limited to these.

[0122] 3-1. Window Film Figure 3 shows a window film as an example of a laminate according to this embodiment. As shown in Figure 3, the window film 2 in this embodiment is composed of, from top to bottom in the figure, a transparent resin film 21a with a hard coat layer 211, an adhesive layer 22a containing an ultraviolet absorber, a transparent resin film 21b, a light diffusion control film 1, a transparent resin film 21c, and an adhesive layer 22b containing an ultraviolet absorber. From the viewpoint of SDGs, the materials constituting the window film 2 in this embodiment may be materials with a high biomass content, materials that can be recycled or reused, or recycled or reused materials.

[0123] In this embodiment, the window film 2 is attached to the window glass 20 or the like via an adhesive layer 22b containing an ultraviolet absorber. In this embodiment, the window film 2 is attached to the inside of the window glass 20, and therefore sunlight enters the window film 2 through the window glass 20. However, the window film 2 may also be attached to the outside of the window glass 20.

[0124] The light diffusion control film 1 is the light diffusion control film 1 according to the embodiment described above. In the window film 2 of this embodiment, it is preferable that the internal structure of the light diffusion control film 1 is a louver structure 11B or a modified structure thereof, but it is not limited thereto.

[0125] In the window film 2 of this embodiment, the adhesive layer 22a containing an ultraviolet absorber and the adhesive layer 22b containing an ultraviolet absorber each correspond to ultraviolet absorption layers. That is, in this embodiment, ultraviolet absorption layers are present on both sides of the light diffusion control film 1.

[0126] The thickness of the ultraviolet absorber-containing adhesive layers 22a and 22b is not particularly limited, as long as it exhibits the desired adhesive strength and satisfies the aforementioned light transmittance at a wavelength of 380 nm. Typically, the thickness is preferably 1 to 100 μm, particularly preferably 5 to 50 μm, and even more preferably 10 to 30 μm.

[0127] The materials for the transparent resin films 21a, 21b, and 21c can be appropriately selected from known transparent resin films, and may be the same material or different materials. Examples of such transparent resin films include polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polyolefin resins such as polyethylene, polypropylene, poly(4-methyl-1-pentene), and poly-1-butene; polycarbonate resins; polyvinyl chloride resins; polyethersulfone resins; polyethylene sulfide resins; styrene resins; acrylic resins; polyamide resins; and cellulose resins such as cellulose acetate. Among these, polyester films, and particularly polyethylene terephthalate films, are preferred.

[0128] One or more of the transparent resin films 21a, 21b, and 21c may contain an ultraviolet absorber. In this case, the transparent resin film, together with the ultraviolet absorber-containing adhesive layers 22a and 22b, becomes the ultraviolet absorbing layer in this embodiment.

[0129] The hard coat layer 211 can be formed from known materials, and its thickness is not particularly limited and can be a general thickness.

[0130] The window film 2 in this embodiment can be manufactured by conventionally known methods and is not particularly limited.

[0131] When the window film 2 in this embodiment is attached to a windowpane, the viewing angle can be controlled such that when the window film 2 is viewed from a predetermined angle, the other side of the window film 2 is visible, and when the window film 2 is viewed from a different angle, the other side of the window film 2 is not visible.

[0132] 3-2. Ambient Light Utilizing Display Body Figure 4 shows an example of an ambient light utilizing display body (for example, a station name sign) as a laminate according to this embodiment. As shown in Figure 4, the ambient light utilizing display body 3 in this embodiment is composed of, from top to bottom in the figure, a transparent resin film 31a, an adhesive layer containing an ultraviolet absorber 32a, a decorative layer 33, a transparent resin film 31b, an adhesive layer containing an ultraviolet absorber 32b, a transparent resin film 31c, a light diffusion control film 1, a transparent resin film 31d, an adhesive layer 34a, a reflective layer 35, a transparent resin film 31e, and an adhesive layer 34b. Note that the transparent resin film 31c and / or transparent resin film 31d may be omitted. From the viewpoint of SDGs, the materials constituting the ambient light utilizing display body 3 in this embodiment may be materials with a high biomass content, materials that can be recycled or reused, or recycled or reused materials.

[0133] In this embodiment, the ambient light-utilizing display unit 3 is attached to a substrate (frame member) 30, etc., via an adhesive layer 34b. In this embodiment, sunlight enters the ambient light-utilizing display unit 3 from above in the figure, that is, from the transparent resin film 31a side.

[0134] The light diffusion control film 1 is the light diffusion control film 1 according to the embodiment described above.

[0135] In the ambient light-utilizing display body 3 of this embodiment, the adhesive layer 32a containing an ultraviolet absorber and the adhesive layer 32b containing an ultraviolet absorber each correspond to ultraviolet absorption layers. Therefore, in this embodiment, there are at least two ultraviolet absorption layers on the ambient light incident side of the light diffusion control film 1.

[0136] The thickness of the ultraviolet absorber-containing adhesive layers 32a and 32b is not particularly limited, as long as it exhibits the desired adhesive strength and satisfies the aforementioned light transmittance at a wavelength of 380 nm. Typically, the thickness is preferably 1 to 100 μm, more preferably 5 to 50 μm, particularly preferably 10 to 40 μm, and even more preferably 15 to 30 μm.

[0137] The materials of the transparent resin films 31a, 31b, 31c, 31d, and 31e can be appropriately selected from known transparent resin films, and may be the same material or different materials. Examples of such transparent resin films include polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polyolefin resins such as polyethylene, polypropylene, poly(4-methyl-1-pentene), and poly-1-butene; polycarbonate resins; polyvinyl chloride resins; polyethersulfone resins; polyethylene sulfide resins; styrene resins; acrylic resins; polyamide resins; cellulose resins such as cellulose acetate; fluorine resins, etc., or laminated films thereof.

[0138] Among the above, the transparent resin film 31a is preferably a fluororesin film with excellent light resistance. The surface of the transparent resin film 31a facing the light may be glossy or matte. The transparent resin films 31b and 31e are preferably polyvinyl chloride film or polyethylene terephthalate film. The transparent resin films 31c and 31d are preferably polyester film, particularly polyethylene terephthalate film.

[0139] One or more of the transparent resin films 31a, 31b, 31c, and 31d may contain an ultraviolet absorber, and it is particularly preferable that the transparent resin films 31a and 31b contain an ultraviolet absorber. In this case, the transparent resin film, together with the ultraviolet absorber-containing adhesive layers 32a and 32b, becomes the ultraviolet absorbing layer in this embodiment.

[0140] The thickness of the transparent resin films 31a and 31b containing the ultraviolet absorber is preferably 10 to 1000 μm, particularly preferably 50 to 500 μm, and even more preferably 80 to 200 μm, from the viewpoint of achieving both ultraviolet absorption and visible light transmission.

[0141] The decorative layer 33 is not particularly limited as long as it can represent the content of the display using characters, patterns, etc., and does not hinder the desired light diffusion effect; conventionally known materials can be used. For example, the decorative layer 33 may be made by printing inks that constitute characters, patterns, etc., on the surface of a transparent resin film 31b.

[0142] The thickness of the decorative layer 13 is not particularly limited, but is preferably 10 to 1000 μm, and more preferably 20 to 500 μm.

[0143] The type of adhesive constituting the adhesive layers 34a and 34b is not particularly limited, and conventionally known adhesives can be used. For example, acrylic adhesives, silicone adhesives, urethane adhesives, rubber adhesives, etc., can be used as the adhesive, and among these, acrylic adhesives are preferred because they easily achieve good tackiness and transparency.

[0144] The thickness of the adhesive layers 34a and 34b is not particularly limited as long as sufficient tackiness can be achieved, but is preferably 1 to 100 μm, and particularly preferably 3 to 30 μm.

[0145] The reflective layer 35 may be a reflective layer having a smooth surface (specular reflective layer), or it may be a retroreflective reflective layer. In the case of a specular reflective layer, it can be formed as a metal vapor-deposited layer by, for example, vapor-depositing a metal onto the surface of the transparent resin film 31e. Examples of metal vapor-deposited layers include aluminum vapor-deposited layers, silver vapor-deposited layers, stainless steel vapor-deposited layers, and copper vapor-deposited layers. In this case, the thickness of the reflective layer 35 can be a thickness that is typical for a metal vapor-deposited layer.

[0146] In the case of a retroreflective layer, for example, a structure can be used in which a large number of corner cubes are arranged on the reflective surface (corner cube type, prism lens type), a structure in which a large number of glass beads are arranged on the reflective surface and covered with a transparent resin film with a space above it (capsule lens type), a structure in which a large number of glass beads are enclosed in a transparent resin sheet (enclosed lens type), or a structure in which a large number of glass beads are arranged exposed on the reflective surface (exposed lens type). In this case, the thickness of the reflective layer 35 is not particularly limited and may be, for example, 0.01 to 1 mm, and particularly 0.1 to 0.5 mm.

[0147] The ambient light-utilizing display unit 3 in this embodiment can be manufactured by conventionally known methods and is not particularly limited.

[0148] If the ambient light-utilizing display unit 3 in this embodiment is used, for example, as a freestanding station name sign (a station name sign installed on a platform at the same height as a person's line of sight), even at stations where there is no surrounding lighting, passengers on the train can see the freestanding station name sign at night by utilizing the light from the train, especially the light leaking from the doors.

[0149] An example of an external light-utilizing display body according to another embodiment is an external light-utilizing display body having a structure in which a first transparent resin film, a first adhesive layer containing an ultraviolet absorber, a second transparent resin film, a light diffusion control film, a third transparent resin film, and a second adhesive layer containing an ultraviolet absorber are laminated in that order, directly or indirectly. The first transparent resin film preferably has a hard coat layer, and it is particularly preferable that the hard coat layer be the outermost layer.

[0150] Each element in the above-described ambient light-utilizing display is the same as that of the ambient light-utilizing display 3 described above. Furthermore, the above-described ambient light-utilizing display may also preferably have a decorative layer and a reflective layer, similar to the ambient light-utilizing display 3 described above. In addition, an adhesive layer without an ultraviolet absorber may be used instead of the second adhesive layer containing an ultraviolet absorber.

[0151] The embodiments described above are provided to facilitate understanding of the present invention and are not intended to limit it. Accordingly, each element disclosed in the above embodiments is intended to include all design modifications and equivalents that fall within the technical scope of the present invention.

[0152] In this specification, when "X to Y" (where X and Y are any numbers) is written, unless otherwise specified, it includes the meaning of "greater than or equal to X and less than or equal to Y," as well as "preferably greater than X" or "preferably less than Y." Similarly, when "greater than or equal to X" (where X is any number) is written, unless otherwise specified, it includes the meaning of "preferably greater than X," and when "less than or equal to Y" (where Y is any number) is written, unless otherwise specified, it also includes the meaning of "preferably less than Y."

[0153] The present invention will be described in more detail below with reference to examples, but the scope of the present invention is not limited to these examples.

[0154] [Example 1] 1. Preparation of light diffusion control composition 2-Hydroxyethyl acrylate (HEA), isophorone diisocyanate (IPDI), and polypropylene glycol (weight-average molecular weight 5000; PPG5000) were reacted to obtain a polyether urethane acrylate with a weight-average molecular weight of 16000. The composition (structure) of the obtained polyether urethane acrylate was HEA / IPDI / PPG5000 / IPDI / PPG5000 / IPDI / PPG5000 / HEA.

[0155] A light diffusion control composition was obtained by blending 60 parts by mass of o-phenylphenoxyethoxyethyl acrylate as a high refractive index component, 40 parts by mass of the above polyether urethane acrylate as a low refractive index component, and 8 parts by mass of 2-hydroxy-2-methyl-1-phenylpropan-1-one as a photopolymerization initiator, and then heating and mixing at 80°C.

[0156] Here, the weight-average molecular weight (Mw) mentioned above is the weight-average molecular weight on a standard polystyrene basis, measured using gel permeation chromatography (GPC) under the following conditions (GPC measurement). <Measurement conditions> ・Measurement device: HLC-8320, manufactured by Tosoh Corporation ・GPC column (passed in the following order): TSK gel superH-H, TSK gel superHM-H, TSK gel superH2000, manufactured by Tosoh Corporation ・Measurement solvent: Tetrahydrofuran ・Measurement temperature: 40℃

[0157] 2. Formation of a light diffusion control film The obtained light diffusion control composition was applied to one side of a long polyethylene terephthalate film (thickness 50 μm; first PET film, no UV absorption; light transmittance at wavelengths of 380 nm, 480 nm, and 580 nm was all over 90%), which was used as a process sheet, to form a coating film. This resulted in obtaining a laminate consisting of the coating film and the process sheet.

[0158] Next, the resulting laminate was placed on a conveyor belt. At this time, the coated side of the laminate was facing upwards, and the longitudinal direction of the process sheet was parallel to the flow direction of the conveyor belt. Then, an ultraviolet irradiation device (manufactured by I-Graphics, product name "ECS-4011GX"), which consists of a linear high-pressure mercury lamp with a cold mirror for focusing, was installed on the conveyor belt on which the laminate was placed. This device can irradiate a target with ultraviolet light focused in a strip (almost linear) shape. When installing the above device, the ultraviolet irradiation device was positioned so that the longitudinal direction of the high-pressure mercury lamp and the flow direction of the conveyor belt were perpendicular to each other.

[0159] Furthermore, when viewed from the longitudinal direction of the high-pressure mercury lamp, the irradiation angle of ultraviolet light emitted from the high-pressure mercury lamp to the laminate was set to 33°, with reference to the normal to the surface of the laminate. Here, the irradiation angle is expressed as a positive value when ultraviolet light is irradiated downstream of the conveyor flow, with reference to the position directly below the high-pressure mercury lamp on the laminate, and the acute angle between the normal to the surface of the laminate and the ultraviolet light is expressed as a negative value when ultraviolet light is irradiated upstream of the conveyor flow.

[0160] Subsequently, the conveyor is activated, moving the laminated material at a speed of 1.0 m / min, while the peak illuminance on the coating surface is 2.5 mW / cm². ２ Total light intensity 40.0 mJ / cm ２ The coating film in the laminate was cured by irradiating it with ultraviolet light under these conditions (this curing is sometimes referred to as "primary curing" for convenience).

[0161] Next, a 38 μm thick polyethylene terephthalate film (second PET film, no UV absorption; light transmittance at wavelengths of 380 nm, 480 nm, and 580 nm is all over 90%) is laminated onto the coated surface of the laminate. Then, a peak illuminance of 190 mW / cm² is applied to the coated surface via this sheet. ２ Total light intensity 180 mJ / cm ２ The coating film in the laminate was cured by irradiating it with ultraviolet light (scattered light) under these conditions (this curing is sometimes referred to as "secondary curing" for convenience). The peak illuminance and integrated light quantity mentioned above were measured by placing a UV meter (manufactured by iGraphics Co., Ltd., product name "i UV Integrated Illuminance Meter UVPF-A1") equipped with a light receiver at the location of the coating film.

[0162] Through the above primary and secondary curing processes, a light-diffusion control film with a thickness of 165 μm was formed from the cured coating. This resulted in a laminate in which a first PET film with a thickness of 50 μm, the light-diffusion control film, and a second PET film with a thickness of 38 μm were laminated in that order. The thickness of the light-diffusion control film was measured using a constant-pressure thickness measuring instrument (manufactured by Takara Seisakusho Co., Ltd., product name "TECLOCK PG-02J").

[0163] Microscopic observation of the cross-section of the formed light diffusion control film revealed that a louver structure was formed inside the light diffusion control film, consisting of multiple plate-like regions arranged alternately in one direction along the film surface.

[0164] 3. Manufacturing of a pseudo-external light-utilizing display In the laminate of light diffusion control films prepared above (first PET film / light diffusion control film / second PET film), an acrylic adhesive layer A containing an ultraviolet absorber (thickness 13 μm, light transmittance at wavelength 380 nm: 0.0%, light transmittance at wavelength 480 nm: 92.2%, light transmittance at wavelength 580 nm: 92.3%) was laminated on the second PET film side.

[0165] A 3 μm thick hard coat layer, made of cured acrylic material, was formed on one surface of a 25 μm thick PET film to obtain a PET film with a hard coat layer (no UV absorption; light transmittance at wavelengths of 380 nm, 480 nm, and 580 nm is all over 90%). Then, an acrylic adhesive layer B containing a UV absorber (13 μm thick, light transmittance at 380 nm: 0.0%, light transmittance at 480 nm: 92.2%, light transmittance at 580 nm: 92.3%) was laminated onto the side of the PET film with the hard coat layer that did not have a hard coat layer.

[0166] The light transmittances of the acrylic adhesive layers (A and B) containing the UV absorber at wavelengths of 380 nm, 480 nm, and 580 nm were measured as follows. First, the acrylic adhesive layers containing the UV absorber were attached to a glass plate and used as a sample. The light transmittance (%) of this sample was then measured using a UV-Vis-NIR spectrophotometer (Shimadzu Corporation, product name "UV-3600"). Based on the measurement results, the light transmittances of the acrylic adhesive layers (A and B) containing the UV absorber at wavelengths of 380 nm, 480 nm, and 580 nm were determined.

[0167] Next, a PET film with a hard coat layer was attached to the first PET film side of the laminate of light diffusion control films (first PET film / light diffusion control film / second PET film) prepared above, via the acrylic adhesive layer B containing the ultraviolet absorber. Furthermore, an acrylic adhesive layer A (thickness 13 μm) containing the ultraviolet absorber was laminated to the second PET film side of the laminate of light diffusion control films (first PET film / light diffusion control film / second PET film).

[0168] In this way, a laminate was obtained as a pseudo-external light-utilizing display body, consisting of, from top to bottom, a PET film with a hard coat layer, an acrylic adhesive layer B containing an ultraviolet absorber, a first PET film, a light diffusion control film, a second PET film, and an acrylic adhesive layer A containing an ultraviolet absorber.

[0169] [Example 2] 2-hydroxyethyl acrylate (HEA), isophorone diisocyanate (IPDI), and polypropylene glycol (weight-average molecular weight 3000; PPG3000) were reacted to obtain a polyether urethane acrylate with a weight-average molecular weight of 3500. The composition (structure) of the obtained polyether urethane acrylate was HEA / IPDI / PPG3000 / IPDI / HEA.

[0170] A light diffusion control composition was prepared in the same manner as in Example 1, except that the above-mentioned polyether urethane acrylate was used as the low refractive index component. Then, using this light diffusion control composition, a light diffusion control film and a laminate as a pseudo-external light-utilizing display were manufactured in the same manner as in Example 1.

[0171] [Example 3] 2-hydroxyethyl acrylate (HEA), isophorone diisocyanate (IPDI), and polypropylene glycol (weight-average molecular weight 3000; PPG3000) were reacted to obtain a polyether urethane acrylate with a weight-average molecular weight of 7000. The composition (structure) of the obtained polyether urethane acrylate was HEA / IPDI / PPG3000 / IPDI / PPG3000 / IPDI / HEA.

[0172] A light diffusion control composition was prepared in the same manner as in Example 1, except that the above-mentioned polyether urethane acrylate was used as the low refractive index component. Then, using this light diffusion control composition, a light diffusion control film and a laminate as a pseudo-external light-utilizing display were manufactured in the same manner as in Example 1.

[0173] [Example 4] 2-hydroxyethyl acrylate (HEA), isophorone diisocyanate (IPDI), and polypropylene glycol (weight-average molecular weight 2000; PPG2000) were reacted to obtain a polyether urethane acrylate with a weight-average molecular weight of 2500. The composition (structure) of the obtained polyether urethane acrylate was HEA / IPDI / PPG2000 / IPDI / HEA.

[0174] A light diffusion control composition was prepared in the same manner as in Example 1, except that the above-mentioned polyether urethane acrylate was used as the low refractive index component. Then, using this light diffusion control composition, a light diffusion control film and a laminate as a pseudo-external light-utilizing display were manufactured in the same manner as in Example 1.

[0175] [Example 5] 2-hydroxyethyl acrylate (HEA), isophorone diisocyanate (IPDI), and polytetramethylene ether glycol (weight-average molecular weight 2000; PTMG2000) were reacted to obtain a polyether urethane acrylate with a weight-average molecular weight of 2500. The composition (structure) of the obtained polyether urethane acrylate was HEA / IPDI / PTMG2000 / IPDI / HEA.

[0176] A light diffusion control composition was prepared in the same manner as in Example 1, except that the above-mentioned polyether urethane acrylate was used as the low refractive index component. Then, using this light diffusion control composition, a light diffusion control film and a laminate as a pseudo-external light-utilizing display were manufactured in the same manner as in Example 1.

[0177] [Example 6] A light diffusion control composition was obtained by blending 50 parts by mass of o-phenylphenoxyethoxyethyl acrylate as a high refractive index component, 50 parts by mass of polyether urethane acrylate prepared in Example 2 as a low refractive index component, 10 parts by mass of 2-hydroxy-2-methyl-1-phenylpropan-1-one as a photopolymerization initiator, 3 parts by mass of dipentaerythritol hexaacrylate as a polyfunctional monomer, 0.05 parts by mass of a hindered phenol antioxidant (manufactured by ADEKA, product name "ADEKA Stab AO-50"), and 0.08 parts by mass of a benzotriazole ultraviolet absorber (manufactured by BASF Japan, product name "Tinuvin 384-2"), and then heating and mixing at 80°C.

[0178] Using the above-mentioned light diffusion control composition, a light diffusion control film and a laminate as a pseudo-external light-utilizing display were manufactured in the same manner as in Example 1.

[0179] [Example 7] 50 parts by mass of o-phenylphenoxyethoxyethyl acrylate as a high refractive index component, 50 parts by mass of polyether urethane acrylate prepared in Example 2 as a low refractive index component, 10 parts by mass of 2-hydroxy-2-methyl-1-phenylpropan-1-one as a photopolymerization initiator, 3 parts by mass of dipentaerythritol hexaacrylate as a polyfunctional monomer, 2 parts by mass of a low basic hindered amine compound having a carbonate skeleton as shown in the following structural formula (B) (hindered amine compound CL, base dissociation constant pKb: 11.3), 0.05 parts by mass of a hindered phenol antioxidant (manufactured by ADEKA, product name "ADEKA Stab AO-50"), and a benzotriazole ultraviolet absorber (manufactured by BASF, product name "Tinuvin After blending with 0.08 parts by mass of (384-2), the mixture was heated and mixed at 80°C to obtain a light diffusion control composition.

[0180]

[0181] Using the above-mentioned light diffusion control composition, a light diffusion control film and a laminate as a pseudo-external light-utilizing display were manufactured in the same manner as in Example 1.

[0182] [Comparative Example 1] 2-hydroxymethyl acrylate (HEMA), isophorone diisocyanate (IPDI), and polypropylene glycol (weight-average molecular weight 5000; PPG5000) were reacted to obtain a polyether urethane acrylate with a weight-average molecular weight of 11000. The composition (structure) of the obtained polyether urethane methacrylate was HEMA / IPDI / PPG5000 / IPDI / PPG5000 / IPDI / HEMA.

[0183] A light diffusion control composition was prepared in the same manner as in Example 1, except that the above-mentioned polyether urethane methacrylate was used as the low refractive index component. Then, using this light diffusion control composition, a light diffusion control film and a laminate as a pseudo-external light-utilizing display were manufactured in the same manner as in Example 1.

[0184] [Comparative Example 2] 2-hydroxymethyl acrylate (HEMA), isophorone diisocyanate (IPDI), and polypropylene glycol (weight-average molecular weight 5000; PPG5000) were reacted to obtain a polyether urethane acrylate with a weight-average molecular weight of 16000. The composition (structure) of the obtained polyether urethane methacrylate was HEMA / IPDI / PPG5000 / IPDI / PPG5000 / IPDI / PPG5000 / IPDI / HEMA.

[0185] A light diffusion control composition was prepared in the same manner as in Example 1, except that the above-mentioned polyether urethane methacrylate was used as the low refractive index component. Then, using this light diffusion control composition, a light diffusion control film and a laminate as a pseudo-external light-utilizing display were manufactured in the same manner as in Example 1.

[0186] [Comparative Example 3] A polyether urethane acrylate with a weight-average molecular weight of 5500 was obtained by reacting 2-hydroxymethyl acrylate (HEMA), isophorone diisocyanate (IPDI), and polypropylene glycol (weight-average molecular weight 5000; PPG5000). The composition (structure) of the obtained polyether urethane methacrylate was HEMA / IPDI / PPG5000 / IPDI / HEMA.

[0187] A light diffusion control composition was prepared in the same manner as in Example 1, except that the above-mentioned polyether urethane methacrylate was used as the low refractive index component. Then, using this light diffusion control composition, a light diffusion control film and a laminate as a pseudo-external light-utilizing display were manufactured in the same manner as in Example 1.

[0188] Table 1 shows the amounts of each component used in each example.

[0189] [Test Example 1] (Measurement of Variable Angle Haze Range) The haze value (%) of the light diffusion control film used in the examples and comparative examples was measured using a variable angle haze meter (manufactured by Toyo Seiki Seisakusho Co., Ltd., product name "Haze Guard Plus"). Specifically, light was irradiated onto the surface of the first PET film in the laminate of the light diffusion control film (first PET film / light diffusion control film / second PET film) while varying the angle of incidence relative to the normal along the longitudinal direction of the light diffusion control film in the range of -70° to 70° (±70° from the normal), and the haze value (%) was measured for each angle of incidence. The details of the measurement conditions were as follows: Light source: C light source Measurement diameter: φ18 mm Integrating sphere aperture diameter: φ25.4 mm

[0190] Next, regarding the results measured above, we identified the range of incident angles within the measurement range of the incident angle (-70° to 70°) where the haze value was 60% or higher (threshold). Furthermore, we calculated the difference between the two angles that make up the endpoints of this range, and defined this as the angle range that yields a haze value of 60% or higher (variable angle haze angle range). The results are shown in Table 2.

[0191] [Test Example 2] (Evaluation of Liquefaction Suppression) The laminates obtained as pseudo-external light-utilizing display bodies in the Examples and Comparative Examples were irradiated with ultraviolet light for 3000 hours using a sunshine weather meter (SWOM) (manufactured by Suga Test Instruments Co., Ltd., product name "S80") in accordance with JIS A1439:2016, at 63±3°C (black panel temperature) and a 50% RH atmosphere (irradiance: 78.5 W / m²). ２ Next, the laminate was disassembled, and the liquefaction of the light diffusion control film was examined. Then, the liquefaction suppression was evaluated based on the following evaluation criteria. The results are shown in Table 2.

[0192] <Evaluation Criteria for Liquefaction Suppression> ○...No liquefaction occurred at all. △...When the light diffusion control film was peeled off from the PET film, some stickiness was observed on the surface of the light diffusion control film. ×...Liquefaction occurred throughout the entire area.

[0193]

[0194]

[0195] As can be seen from Table 2, the laminate obtained as a pseudo-external light-utilizing display obtained in the examples showed suppressed liquefaction of the light diffusion control film due to prolonged ultraviolet irradiation.

[0196] The light diffusion control film and laminate according to the present invention can be suitably used, for example, in window films for controlling the viewing angle, or in ambient light-utilizing display devices (such as station name signs) that improve visibility from a predetermined angle.

[0197] 1...Light diffusion control film 11A...Column structure 111...Columnar object with relatively high refractive index 112...Region with relatively low refractive index 11B...Louver structure 113...Plate-shaped region with relatively high refractive index 114...Region with relatively low refractive index 2...Window film 211...Hard coat layer 21a, 21b, 21c...Transparent resin film 22a, 22b...Adhesive layer with UV absorber 20...Window glass 2 3...External light utilization type display 31a, 31b, 31c, 31d, 31e...Transparent resin film 32a, 32b...Adhesive layer with UV absorber 33...Decorative layer 34a, 34b...Adhesive layer 35...Reflective layer 30...Substrate (frame member)

Claims

1. A laminate for use in an environment where ambient light is irradiated, comprising: a light diffusion control film having an internal structure in which multiple regions with relatively high refractive indices are contained within a region with a relatively low refractive index; and an ultraviolet absorption layer located on the ambient light incidence side of the light diffusion control film, wherein the light diffusion control film is obtained from a composition containing a high refractive index component and a low refractive index component having a lower refractive index than the high refractive index component, and the low refractive index component is a urethane acrylate having a structure derived from a hydroxyl group-containing acrylic monomer represented by the following general formula (I). A laminate characterized by the following: (wherein R is a hydrogen atom and n is an integer of 1 or more.) 2. The laminate according to claim 1, characterized in that the urethane acrylate is a compound formed from the hydroxyl group-containing acrylic monomer, a compound containing at least two isocyanate groups, and a polyalkylene glycol.

3. The laminate according to claim 1, characterized in that the weight-average molecular weight of the urethane acrylate is 3,000 to 20,000.

4. The laminate according to claim 1, characterized in that the high refractive index component is a (meth)acrylic acid ester containing a plurality of aromatic rings.

5. The laminate according to claim 1, characterized in that the light transmittance of the ultraviolet absorbing layer at a wavelength of 380 nm is 30% or less.

6. The laminate according to claim 1, characterized in that the laminate is a window film.

7. The laminate according to claim 6, characterized in that the light diffusion control film is provided with ultraviolet absorbing layers on both sides.

8. The laminate according to claim 1, characterized in that the laminate is an ambient light-utilizing display body.

9. The laminate according to claim 8, characterized in that the ambient light-utilizing display body is a station name sign.

10. A window film having a structure in which a first transparent resin film, a first adhesive layer containing an ultraviolet absorber, a second transparent resin film, a light diffusion control film, a third transparent resin film, and a second adhesive layer containing an ultraviolet absorber are directly or indirectly laminated in that order, wherein the light diffusion control film is obtained from a composition containing a high refractive index component and a low refractive index component having a lower refractive index than the high refractive index component, and the low refractive index component is a urethane acrylate having a structure derived from a hydroxyl group-containing acrylic monomer represented by the following general formula (I). A window film characterized by the following: (wherein R is a hydrogen atom and n is an integer of 1 or more.) 11. An external light-utilizing display body having a structure in which a first transparent resin film, a first adhesive layer containing an ultraviolet absorber, a decorative layer, a second transparent resin film, a second adhesive layer containing an ultraviolet absorber, a light diffusion control film, a first adhesive layer, a reflective layer, a third transparent resin film, and a second adhesive layer are directly or indirectly laminated in that order, wherein the light diffusion control film is obtained from a composition containing a high refractive index component and a low refractive index component having a lower refractive index than the high refractive index component, and the low refractive index component is a urethane acrylate having a structure derived from a hydroxyl group-containing acrylic monomer represented by the following general formula (I). An external light-utilizing display unit characterized by (wherein R is a hydrogen atom and n is an integer of 1 or more).

12. The external light-utilizing display body according to claim 11, characterized in that a fourth transparent resin film is provided between the second ultraviolet absorber-containing adhesive layer and the light diffusion control film.

13. The external light-utilizing display body according to claim 11, characterized in that a fifth transparent resin film is provided between the light diffusion control film and the first adhesive layer.

14. An external light-utilizing display having a structure in which a first transparent resin film, a first adhesive layer, a second transparent resin film, a light diffusion control film, a third transparent resin film, and a second adhesive layer are directly or indirectly laminated in that order, wherein the first adhesive layer is an adhesive layer containing an ultraviolet absorber, the light diffusion control film is obtained from a composition containing a high refractive index component and a low refractive index component having a lower refractive index than the high refractive index component, and the low refractive index component is a urethane acrylate having a structure derived from a hydroxyl group-containing acrylic monomer represented by the following general formula (I). An external light-utilizing display unit characterized by (wherein R is a hydrogen atom and n is an integer of 1 or more).

15. The external light-utilizing display body according to claim 14, characterized in that the second adhesive layer is an adhesive layer containing an ultraviolet absorber.

16. The external light-utilizing display body according to claim 14, characterized in that the first transparent resin film has a hard coat layer.

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