Transparent laminates, image display devices, flexible devices

Abstract

To provide a transparent laminate that exhibits excellent bendability while having a high hardness.SOLUTION: A transparent laminate of the present disclosure includes a substrate and a hard coat layer laminated on at least one surface of the substrate. The transparent laminate has a pencil hardness of H or higher at a load of 750 g on a surface of the hard coat layer. The transparent laminate has a minimum bendable radius of 1.5 mm or less when the transparent laminate is subjected to a cylindrical mandrel test such that the surface of the hard coat layer of the transparent laminate is bent into a concave shape. The transparent laminate has a ratio of an indentation elastic modulus to an indentation hardness (indentation elastic modulus / indentation hardness) of 6.0 or greater in a microhardness test.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This disclosure relates to transparent laminates, image display devices, and flexible devices. [Background technology]

[0002] To enhance the portability of mobile information terminals such as smartphones and tablets, there is a growing demand for foldable devices such as foldable displays and touch panels. A known configuration for the outermost surface of such foldable device displays is the use of a hard coat layer as a cover material. Furthermore, this hard coat layer requires high hardness to prevent scratches and indentations while maintaining transparency and aesthetic appeal. An example of an invention using such a high-hardness hard coat layer is found in Patent Document 1. [Prior art documents] [Non-patent literature]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-081716 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] However, the hard coat layer described in Patent Document 1 had the problem that increasing its hardness reduced its flexibility (flexibility), making it more prone to cracking in the hard coat layer or the substrate.

[0005] This disclosure solves the above-mentioned problems, and its purpose is to provide a transparent laminate that is highly rigid yet highly flexible. [Means for solving the problem]

[0006] The inventors of this disclosure have found that a transparent laminate having a substrate and a hard coat layer laminated on at least one surface of the substrate, is highly flexible while being hard if the surface of the hard coat layer satisfies a specific range for pencil hardness, minimum bending radius, and ratio of indentation modulus to indentation hardness in microhardness measurement. This disclosure is completed based on these findings.

[0007] In other words, the transparent laminate is a transparent laminate having a base material and a hard coat layer laminated on at least one surface of the base material, wherein the pencil hardness at a 750g load on the surface of the hard coat layer is H or higher, the minimum bending radius when a cylindrical mandrel test is performed with the surface of the hard coat layer of the transparent laminate concave is 1.5 mm or less, and the ratio of indentation modulus to indentation hardness (indentation modulus / indentation hardness) in a microhardness test of the transparent laminate is 6.0 or higher.

[0008] The hard coat surface exhibits high hardness while maintaining excellent flexibility because, as described above, the pencil hardness is H or higher, the minimum bending radius is 1.5 mm or less, and the ratio of the indentation modulus to the indentation hardness is 6.0 or higher.

[0009] Preferably, the transparent laminate has a haze of 1.0% or less in the hard coat layer.

[0010] The transparent laminate described above is a cured product of a curable composition in which the hard coat layer contains one or more curable compounds, and it is preferable that the curable compound contains an aliphatic compound having two or more cationic polymerizable groups in its molecule.

[0011] It is preferable that the above curable compound includes polyorganosylsesquioxane.

[0012] The curable compound preferably contains two or more of the above-mentioned aliphatic compounds. Having the above configuration makes it easy to achieve both high hardness and flexibility.

[0013] Preferably, the above curable composition further contains a curing catalyst.

[0014] It is preferable that the curing catalyst described above contains a cationic polymerization initiator.

[0015] It is preferable that the curing catalyst described above contains a radical polymerization initiator.

[0016] Furthermore, it is preferable that the transparent laminate does not contain any compounds corresponding to PFAS in the hard coat layer.

[0017] The transparent laminate described above preferably has a surface protective film on at least one surface.

[0018] Preferably, the transparent laminate has the hard coat layer on one side of the substrate and the adhesive layer on the other side.

[0019] The above substrate is preferably glass with a thickness of 30 to 100 μm.

[0020] Furthermore, this disclosure provides an image display device comprising the transparent laminate described above.

[0021] The image display device described above is preferably a flexible display.

[0022] The above image display device is preferably an organic electroluminescent display device.

[0023] Furthermore, this disclosure provides a flexible device including the image display device described above. [Effects of the Invention]

[0024] The transparent laminate of this disclosure has high hardness while exhibiting excellent flexibility. Therefore, it can be suitably used in image display devices such as flexible displays. [Modes for carrying out the invention]

[0025] In this disclosure, "compounds corresponding to PFAS" refers to perfluoroalkyl compounds and polyfluoroalkyl compounds as a general term.

[0026] [Transparent laminate] The transparent laminate of this disclosure is a transparent laminate having a substrate and a hard coat layer laminated on at least one surface of the substrate, wherein the pencil hardness at a 750g load on the surface of the hard coat layer is H or higher, the minimum bending radius when the transparent laminate is bent with the hard coat layer side concave and a cylindrical mandrel test is performed is 1.5 mm or less, and the ratio of indentation modulus to indentation hardness (indentation modulus / indentation hardness) in the microhardness test of the transparent laminate is 6.0 or higher. The transparent laminate of this disclosure having the above configuration is highly hard yet has excellent flexibility.

[0027] The transparent laminate described above may have layers other than the substrate and the hard coat layer. Examples of these other layers include a surface protective film, an adhesive layer, an undercoat layer for bonding the substrate and the hard coat layer, an anti-reflective layer, an anti-glare layer, an anti-fingerprint layer, an anti-fouling layer, an anti-scratch fingerprint layer, an antibacterial layer, a bonding layer, a polarizing layer, and the like. These other layers may be formed on only one side of the substrate or on both sides. Furthermore, if these other layers are formed on both sides of the substrate, the same layers may be laminated on each side, or layers with different thicknesses and compositions may be laminated on each side.

[0028] The transparent laminate described above has a pencil hardness of H or higher, preferably 2H or higher, on the surface of the hard coat layer, as measured according to JIS K5600-5-4. A pencil hardness of H or higher ensures sufficient surface hardness, making it easy to exhibit abrasion resistance. If hard coat layers are laminated on both sides of the transparent laminate, it is sufficient for at least one side to satisfy the above range.

[0029] In a cylindrical mandrel test conducted in accordance with JIS K5600-5-1, in which the surface of the hard coat layer is bent to a concave shape, the transparent laminate exhibits a minimum bending diameter of 1.5 mm or less without cracking. This minimum bending diameter of 1.5 mm or less ensures sufficient flexibility. If hard coat layers are laminated on both sides of the transparent laminate, it is sufficient for at least one side to satisfy the above range, and it is preferable that the hard coat layer with a pencil hardness of H or higher satisfies the minimum bending diameter.

[0030] The transparent laminate described above preferably has an indentation modulus of 400 to 4000 MPa in the microhardness measurement of the hard coat layer surface, more preferably 600 to 3500 MPa, and even more preferably 800 to 3000 MPa. An indentation modulus of 400 MPa or higher tends to result in excellent surface hardness. An indentation modulus of 4000 MPa or lower allows for a balance between rigidity and elongation and flexibility.

[0031] The transparent laminate described above preferably has an indentation hardness of 50 to 500 MPa in the microhardness measurement of the hard coat layer surface, more preferably 70 to 450 MPa, and even more preferably 90 to 400 MPa. An indentation hardness of 50 MPa or higher increases the surface hardness of the transparent laminate, making it less susceptible to dents and scratches. Furthermore, an indentation hardness of 500 MPa or lower tends to result in excellent flexibility and bendability. When hard coat layers are laminated on both sides of the transparent laminate, it is sufficient for at least one side to satisfy the above range, and it is preferable that the hard coat layer with a pencil hardness of H or higher satisfies the above indentation hardness.

[0032] The transparent laminate described above has a ratio of indentation modulus to indentation hardness (indentation modulus / indentation hardness) of 6.0 or higher, preferably 6.5 or higher, and more preferably 7.0 or higher. A ratio of 6.0 or higher allows for sufficient surface hardness while maintaining excellent flexibility. While there is no particular upper limit, it is preferable that the ratio be 80.0 or lower to ensure sufficient surface hardness.

[0033] The thickness of the transparent laminate is preferably 10 to 500 μm, more preferably 30 to 400 μm, and particularly preferably 50 to 300 μm. A thickness of 10 μm or more makes it easy to achieve sufficient surface hardness. Furthermore, a thickness of 500 μm or less makes it easy to achieve sufficient flexibility.

[0034] <Base material> As the substrate for the transparent laminate of this disclosure, known or conventional substrates such as plastic substrates, metal substrates, ceramic substrates, semiconductor substrates, glass substrates, paper substrates, wood substrates (wooden substrates), and substrates with painted surfaces can be used. Among these, glass substrates and plastic substrates are preferred from the viewpoint of exhibiting transparency, and glass substrates are particularly preferred. Furthermore, the above substrate may have a single-layer structure or a multi-layer structure, and may be composed of one type of material or may use two or more types of materials.

[0035] The glass substrate described above may be chemically strengthened to improve its resistance to cracking when the glass is thinned, and to make it a panel that can withstand practical use. It is also preferable that the edges are treated to ensure sufficient strength as a substrate. Furthermore, a treatment layer or coating film may be formed on any of the surfaces to improve abrasion resistance, smoothness, and crack resistance.

[0036] The thickness of the above-mentioned substrate is preferably, for example, 30 to 100 μm, more preferably 40 to 95 μm, and even more preferably 50 to 90 μm. When the thickness of the glass substrate is 30 μm or more, it is easy to achieve sufficient strength as a substrate. Furthermore, when the thickness of the glass substrate is 100 μm or less, it is easy to achieve flexibility.

[0037] The transparent laminate may have a surface protective film. The surface protective film protects the surface of the hard coat layer, and it is preferable that the transparent laminate has a surface protective film on at least one surface. Furthermore, if the hard coat layer is formed on both surfaces of the substrate, the surface protective film may be present on both surfaces of the transparent laminate.

[0038] The above-mentioned surface protection film can be a known or conventional surface protection film, and is not particularly limited, but for example, a plastic film having an adhesive layer on its surface can be used. Examples of the above-mentioned plastic film include plastic films formed from plastic materials such as polyester (polyethylene terephthalate, polyethylene naphthalate, etc.), polyolefin (polyethylene, polypropylene, cyclic polyolefin, etc.), polystyrene, acrylic resin, polycarbonate, epoxy resin, fluororesin, silicone resin, diacetate resin, triacetate resin, polyarylate, polyvinyl chloride, polysulfone, polyethersulfone, polyetheretherimide, polyimide, and polyamide. Examples of the above-mentioned adhesive layer include an adhesive layer formed from one or more known or conventional adhesives such as acrylic adhesives, silicone adhesives, natural rubber adhesives, synthetic rubber adhesives, ethylene-vinyl acetate copolymer adhesives, ethylene-(meth)acrylic acid ester copolymer adhesives, styrene-isoprene block copolymer adhesives, and styrene-butadiene block copolymer adhesives. The adhesive layer may contain various additives (e.g., antistatic agents, slip agents, etc.). The plastic film and adhesive layer may each have a single-layer structure or a multi-layer (multi-layer) structure. Furthermore, the thickness of the surface protection film is not particularly limited and can be selected as appropriate.

[0039] Examples of the surface protection films mentioned above include commercially available products such as the "Sanitect" series (manufactured by San-ei Chemicals Co., Ltd.), the "E-MASK" series (manufactured by Nitto Denko Corporation), the "Mustack" series (manufactured by Fujimori Kogyo Co., Ltd.), the "Hitarex" series (manufactured by Hitachi Chemical Co., Ltd.), and the "Alfan" series (manufactured by Oji F-Tex Co., Ltd.).

[0040] Furthermore, the transparent laminate may have an adhesive layer. Preferably, the adhesive layer is laminated on the side of the transparent laminate opposite to the side on which the hard coat layer of the substrate is laminated. That is, if the transparent laminate has an adhesive layer, it is preferable that the hard coat layer is on one side of the substrate and the adhesive layer is on the other side. It is even more preferable that the adhesive layer is on the surface of one of the transparent laminates.

[0041] The adhesive used to constitute the above-mentioned adhesive layer can be the same adhesive as that exemplified in the above-mentioned surface protective film. Among these, acrylic adhesives and silicone adhesives are preferred, with acrylic adhesives being particularly preferred, due to their good transparency and the fact that sufficient adhesive strength can be obtained even when thin. Note that only one type of adhesive may be used, or two or more types may be used.

[0042] The thickness of the adhesive layer is, for example, 0.1 to 50 μm, preferably 1 to 45 μm, more preferably 2 to 40 μm, and even more preferably 5 to 35 μm.

[0043] The above adhesive layer can be obtained by applying the above adhesive to at least one surface of the substrate and curing it.

[0044] Furthermore, the transparent laminate may have an undercoat layer. In particular, when the transparent laminate has a glass substrate, there may be problems with the adhesion between the substrate and the hard coat layer, and it is preferable to have an undercoat layer between the glass substrate and the hard coat layer.

[0045] The material for the undercoat layer is not particularly limited, and examples include resins. Examples of resins include (meth)acrylic resin, urethane resin, (meth)acrylic urethane copolymer, vinyl chloride-vinyl acetate copolymer, polyester, butyral resin, chlorinated polypropylene, chlorinated polyethylene, epoxy resin, silicone resin, etc. One type of these resin may be used, or two or more types may be used.

[0046] The thickness of the undercoat layer is preferably 0.1 to 30 μm, and more preferably 1 to 20 μm. When the thickness of the undercoat layer is within this range, it is possible to achieve good adhesion with the substrate while also easily improving the surface hardness of the hard coat layer when a hard coat layer is laminated on top of it.

[0047] The above undercoat layer can be obtained by coating the above resin onto at least one surface of the substrate and curing it.

[0048] Conventional coating methods can be used to form the undercoat layer described above. For example, well-known methods such as dipping, roll coating, gravure coating, reverse coating, air knife coating, comma coating, die coating, screen printing, spray coating, gravure offset method, and organic vapor deposition can be used. As for the curing treatment, light irradiation using, for example, a mercury lamp, xenon lamp, carbon arc lamp, metal halide lamp, sunlight, electron beam source, laser light source, LED light source, etc., can be used. The cumulative irradiation dose can be, for example, 300 to 10000 mJ / cm². 2 It is preferable to irradiate within the range in which this occurs. Alternatively, a film pre-coated on another substrate by the above forming method may be transferred to the substrate using a transfer method such as adhesive transfer, thermal transfer, or UV transfer.

[0049] After light irradiation is complete, it is preferable to further anneal the material to remove internal strain, for example, by heating it at a temperature of 100 to 200°C for about 30 minutes to 1 hour.

[0050] <Hard coat layer> The hard coat layer may be formed on only one side of the substrate in the transparent laminate, or on both sides of the substrate. However, if the transparent laminate has the adhesive layer, it is preferable that the hard coat layer be formed on only one side of the substrate. When hard coat layers are formed on both sides of the substrate, it is sufficient that at least one side satisfies the physical properties of the hard coat layers described above and below. Each hard coat layer may be the same, or layers with different thicknesses and compositions may be laminated. Furthermore, a hard coat layer may be formed on one side of the substrate and the other layer may be formed on the other side. From the viewpoint of suppressing crack occurrence, it is preferable that the hard coat layer is formed on at least one side of the substrate and the hard coat layer or the other layer is formed on the other side.

[0051] The hard coat layer described above is preferably formed from a cured product of a curable composition containing one or more curable compounds. That is, the curable composition preferably contains one or more curable compounds. The curable compounds may be used by one or two or more.

[0052] The curable compound preferably contains polyorganosilsesquioxane. By including polyorganosilsesquioxane, the curable composition is less prone to shrinkage during curing, thereby enabling the formation of a hard coat layer with high hardness and superior scratch resistance. Examples of polyorganosilsesquioxane include radical polymerizable polyorganosilsesquioxane and cationic polymerizable polyorganosilsesquioxane, among which cationic polymerizable polyorganosilsesquioxane is preferred, and of which cationic polymerizable polyorganosilsesquioxane is more preferably photocationically polymerizable polyorganosilsesquioxane.

[0053] The above-mentioned radically polymerizable polyorganosylsesquioxane has a radically polymerizable functional group within its molecule. Examples of the radically polymerizable functional group include a (meth)acryloyl group, a (meth)acrylamide group, a vinyl group, and a vinylthio group.

[0054] The above cationic polymerizable polyorganosylsesquioxane has a cationic polymerizable functional group within its molecule. Examples of the cationic polymerizable functional group include epoxy groups, oxetane groups, vinyl ether groups, and vinyl phenyl groups. Among these, epoxy groups are preferred from the viewpoint of being able to increase the surface hardness of the hard coat layer.

[0055] The epoxy group-containing group mentioned above includes known and conventional groups having an oxirane ring, and is not particularly limited. However, from the viewpoint of the curability of the curable composition and the heat resistance of the hard coat layer, the group represented by formula (1a), the group represented by formula (1b), the group represented by formula (1c), and the group represented by formula (1d) are preferred, more preferably the group represented by formula (1a), the group represented by formula (1c), and even more preferably the group represented by formula (1a). [ka] [ka] [ka] [ka]

[0056] In the above formula (1a), R 1arepresents a linear or branched alkylene group. Examples of the linear or branched alkylene group include linear or branched alkylene groups having 1 to 10 carbon atoms such as a methylene group, a methylmethylene group, a dimethylmethylene group, an ethylene group, a propylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, a decamethylene group, and the like. Among them, R 1a from the viewpoint of the curability of the curable composition, a linear alkylene group having 1 to 4 carbon atoms or a branched alkylene group having 3 or 4 carbon atoms is preferable, more preferably an ethylene group, a trimethylene group, a propylene group, and even more preferably an ethylene group or a trimethylene group.

[0057] In the above formula (1b), R 1b represents a linear or branched alkylene group, and the same groups as R 1a are exemplified. Among them, R 1b from the viewpoint of the curability of the curable composition, a linear alkylene group having 1 to 4 carbon atoms or a branched alkylene group having 3 or 4 carbon atoms is preferable, more preferably an ethylene group, a trimethylene group, a propylene group, and even more preferably an ethylene group or a trimethylene group.

[0058] In the above formula (1c), R 1c represents a linear or branched alkylene group, and the same groups as R 1a are exemplified. Among them, R 1c from the viewpoint of the curability of the curable composition, a linear alkylene group having 1 to 4 carbon atoms or a branched alkylene group having 3 or 4 carbon atoms is preferable, more preferably an ethylene group, a trimethylene group, a propylene group, and even more preferably an ethylene group or a trimethylene group.

[0059] In the above formula (1d), R 1d represents a linear or branched alkylene group, and the same groups as R 1a are exemplified. Among them, R 1dFrom the viewpoint of the curability of the curable composition, linear alkylene groups having 1 to 4 carbon atoms and branched alkylene groups having 3 or 4 carbon atoms are preferred, more preferably ethylene groups, trimethylene groups, propylene groups, and even more preferably ethylene groups and trimethylene groups.

[0060] R in equation (1) 1 In particular, the group represented by the above formula (1a) is R 1a A group in which the group is an ethylene group [particularly a 2-(3,4-epoxycyclohexyl)ethyl group] is preferred.

[0061] Examples of the polyorganosylsesquioxanes mentioned above include compounds having a structural unit represented by the following formula (1). [R 1 SiO 3 / 2 (1)

[0062] The constituent unit represented by the above formula (1) is generally [RSiO 3 / 2 This is a silsesquioxane structural unit (so-called T unit) represented by ]. In the above formula, R represents a hydrogen atom or a monovalent organic group, and the same applies hereafter. The structural unit represented by formula (1) above is formed by hydrolysis and condensation reactions of the corresponding hydrolyzable trifunctional silane compound. In this specification, a compound having the structural unit represented by formula (1) above may be referred to as "silsesquioxane (X)". R in formula (1) 1 This indicates a group containing the above-mentioned cationic polymerizable functional group (a monovalent group).

[0063] Silsesquioxane (X) may have only one of the constituent units represented by formula (1) above, or it may have two or more of the constituent units represented by formula (1) above.

[0064] Silsesquioxane (X) is a silsesquioxane constituent unit [RSiO 3 / 2 In addition to the constituent units represented by formula (1) above, the system may also have constituent units represented by formula (2) below. [R 2SiO 3 / 2 (2)

[0065] The constituent unit represented by the above formula (2) is generally [RSiO 3 / 2 This is a silsesquioxane structural unit (T unit) represented by ]. That is, the structural unit represented by formula (2) above is formed by the hydrolysis and condensation reaction of the corresponding hydrolyzable trifunctional silane compound.

[0066] R in equation (2) above 2 This represents a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted cycloalkyl group, or a substituted or unsubstituted alkyl group. Examples of the aryl group include phenyl, tolyl, and naphthyl groups. Examples of the aralkyl group include benzyl and phenethyl groups. Examples of the cycloalkyl group include cyclobutyl, cyclopentyl, and cyclohexyl groups. Examples of the alkyl group include linear or branched alkyl groups such as methyl, ethyl, propyl, n-butyl, isopropyl, isobutyl, s-butyl, t-butyl, and isopentyl groups.

[0067] The above-mentioned substituted aryl groups, substituted aralkyl groups, substituted cycloalkyl groups, and substituted alkyl groups include groups in which a hydrogen atom or part or all of the main chain skeleton in each of the above-mentioned aryl groups, aralkyl groups, cycloalkyl groups, and alkyl groups is substituted with at least one selected from the group consisting of alkyl groups (especially linear or branched alkyl groups having 1 to 10 carbon atoms), ether groups, ester groups, carbonyl groups, siloxane groups, halogen atoms (such as fluorine atoms), mercapto groups, amino groups, and hydroxyl groups.

[0068] Among them, R 2 The preferred members are substituted or unsubstituted aryl groups, substituted or unsubstituted alkyl groups, more preferably substituted or unsubstituted aryl groups, and even more preferably phenyl groups.

[0069] The proportions of each silsesquioxane constituent unit (constituent unit represented by formula (1) and constituent unit represented by formula (2)) in silsesquioxane (X) can be appropriately adjusted by the composition of the raw materials (hydrolyzable trifunctional silane) used to form these constituent units.

[0070] Silsesquioxane (X) is, in particular, R 1 The constituent unit represented by the above formula (1) is a group containing an alicyclic epoxy group, and R 2 It is preferable that the material contains at least one structural unit represented by formula (2) above, wherein the aryl group may have substituents. In this case, the surface hardness, flexibility, processability, and flame retardancy of the hard coat layer tend to be superior.

[0071] Silsesquioxane (X) is a T unit, and in addition to the constituent units represented by formula (1) and formula (2) above, it also contains [R3SiO 1 / 2 The constituent unit represented by ] (so-called M unit), [R2SiO 2 / 2 The constituent units represented by ] (so-called D units), and [SiO 4 / 2 It may have at least one siloxane constituent unit selected from the group consisting of constituent units represented by ] (so-called Q units). Note that R in the above M unit and the above D unit is R in the constituent unit represented by formula (1) above. 1 and the constituent unit R represented by the above formula (2) 2 Similar groups can be cited. Examples of silsesquioxane constituent units other than the constituent units represented by formula (1) and formula (2) above include the constituent unit represented by formula (3) below. [HSiO 3 / 2 (3)

[0072] Silsesquioxane (X) contains a constituent unit (T3 isomer) represented by the following formula (I). Furthermore, it may also contain a constituent unit (T2 isomer) represented by the following formula (II). [R a SiO 3 / 2 ] (I) [R b SiO2 / 2 (OR c )] (II)

[0073] Furthermore, the constituent unit represented by formula (I) above can be described in more detail as formula (I') below. Similarly, the constituent unit represented by formula (II) above can be described in more detail as formula (II') below. In the structure represented by formula (I') below, the three oxygen atoms bonded to the silicon atom are each bonded to other silicon atoms (silicon atoms not shown in formula (I')). On the other hand, in the structure represented by formula (II') below, the two oxygen atoms located above and below the silicon atom are each bonded to other silicon atoms (silicon atoms not shown in formula (II')). In other words, both the T3 and T2 forms are constituent units (T units) formed by the hydrolysis and condensation reactions of the corresponding hydrolyzable trifunctional silane compounds. [ka] [ka]

[0074] R in equation (I) above a (R in formula (I')) a (The same applies to R in equation (II)) b (R in equation (II')) b (The same applies to ) which each represents a group containing a cationic polymerizable functional group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted alkyl group, or a hydrogen atom. a and R b A concrete example of this is R in equation (1) above. 1 , R in equation (2) above 2 Similar examples are given. Note that R in equation (I) a and R in equation (II) bThese groups are, respectively, derived from groups (groups other than alkoxy groups and halogen atoms) bonded to the silicon atom in the hydrolyzable trifunctional silane compound used as a raw material for silsesquioxane (X), or, for example, if the cationic polymerizable functional group is an epoxy group, they are groups obtained by epoxidizing the groups (groups other than alkoxy groups and halogen atoms) bonded to the silicon atom in the hydrolyzable trifunctional silane compound used as a raw material for silsesquioxane (X).

[0075] R in equation (II) above c (R in equation (II')) c (The same applies to R in formula (II)). R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Examples of alkyl groups having 1 to 4 carbon atoms include linear or branched alkyl groups having 1 to 4 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, and isobutyl groups. Among these, methyl and ethyl groups are preferred, and methyl groups are more preferred. c The alkyl group in this context generally originates from the alkyl group that forms the alkoxy group in the hydrolyzable silane compound used as a raw material for silsesquioxane (X).

[0076] The molar ratio [constituent unit represented by formula (I) / constituent unit represented by formula (II)] (sometimes written as "T3 / T2") of the constituent unit (T3) represented by formula (I) in silsesquioxane (X) is not particularly limited, but is preferably 5 or more, more preferably 5 to 20, even more preferably 5 to 18, even more preferably 6 to 16, even more preferably 7 to 15, and particularly preferably 8 to 14. By setting the above molar ratio [T3 / T2] to 5 or more, the surface hardness of the hard coat layer tends to improve further.

[0077] The above molar ratio [T3 / T2] for silsesquioxane (X) is, for example, 29 This can be determined by Si-NMR spectroscopy. 29In the Si-NMR spectrum, the silicon atoms in the constituent unit (T3 form) represented by formula (I) and the silicon atoms in the constituent unit (T2 form) represented by formula (II) show signals (peaks) at different positions (chemical shifts). Therefore, the molar ratio [T3 form / T2 form] can be determined by calculating the integral ratio of these respective peaks. Specifically, for example, if silsesquioxane (X) is represented by formula (1) above, R 1 When the constituent unit is a 2-(3,4-epoxycyclohexyl)ethyl group, the silicon atom signal in the structure represented by formula (I) (T3 form) appears at -64 to -70 ppm, and the silicon atom signal in the structure represented by formula (II) (T2 form) appears at -54 to -60 ppm. Therefore, in this case, the molar ratio [T3 form / T2 form] can be determined by calculating the integral ratio of the signal at -64 to -70 ppm (T3 form) and the signal at -54 to -60 ppm (T2 form).

[0078] Silsesquioxane (X) 29 Si-NMR spectra can be measured, for example, using the following apparatus and conditions. Measurement device: Product name "JNM-ECA500NMR" (manufactured by JEOL Ltd.) Solvent: Deuterated chloroform Total number of times: 1800 Measurement temperature: 25℃

[0079] The above molar ratio [T3 / T2] of silsesquioxane(X) being 5 or greater means that a certain amount of T2 isomers are present relative to T3 isomers in silsesquioxane(X). Examples of such T2 isomers include the constituent units represented by the following formula (4), the constituent units represented by the following formula (5), and the constituent units represented by the following formula (6). In formula (4) below, R 1 and R in equation (5) below 2 These are R in equation (1) above, respectively. 1 and R in equation (2) above 2 This is the same as R in equations (4) to (6) below. c R in equation (II)c Similarly, it represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. [R 1 SiO 2 / 2 (OR c )] (4) [R 2 SiO 2 / 2 (OR c )] (5) [HSiO 2 / 2 (OR c )] (6)

[0080] The polyorganosilsesquioxane (especially silsesquioxane(X)) may be a silsesquioxane having a cage-like structure (cage-type silsesquioxane). Cage-type silsesquioxanes include fully cage-type silsesquioxanes and incomplete cage-type silsesquioxanes, but incomplete cage-type silsesquioxanes are preferred.

[0081] Generally, a fully caged silsesquioxane is a polyorganosilsesquioxane composed solely of the T3 isomer, with no T2 isomer present in the molecule. That is, the molar ratio [T3 / T2] is 5 or greater, and furthermore, as described later, the FT-IR spectrum is 1100 cm⁻¹. -1 The presence of a single intrinsic absorption peak in the vicinity suggests that silsesquioxanes have an incomplete cage-type silsesquioxane structure.

[0082] Whether silsesquioxane(X) has a cage-type (incomplete cage-type) silsesquioxane structure can be confirmed by FT-IR spectroscopy [Reference: RHRaney, M.Itoh, A.Sakakibara and T.Suzuki, Chem. Rev. 95, 1409 (1995)]. Specifically, in the FT-IR spectrum at 1050 cm⁻¹ -1 Nearby and 1150cm -1 They do not have intrinsic absorption peaks in the vicinity, and at 1100 cm -1If there is a single intrinsic absorption peak in the vicinity, silsesquioxane(X) can be identified as having a cage-type (incomplete cage-type) silsesquioxane structure. In contrast, generally, in the FT-IR spectrum, at 1050 cm⁻¹... -1 Nearby and 1150cm -1 If there are intrinsic absorption peaks in the vicinity, it is identified as having a ladder-type silsesquioxane structure. The FT-IR spectrum of silsesquioxane(X) can be measured, for example, using the following apparatus and conditions. Measuring device: Product name "FT-720" (manufactured by Horiba, Ltd.) Measurement method: transmission method Resolution: 4cm -1 Measurement wave number range: 400~4000cm -1 Total number of times: 16

[0083] The ratio (total amount) of constituent units having cationic polymerizable functional groups (e.g., constituent units represented by formula (1) above, constituent units represented by formula (4) above, etc.) to the total amount of siloxane constituent units [total amount of all siloxane constituent units; M units, D units, T units, and Q units] (100 mol%) in polyorganosilsesquioxane is not particularly limited, but is preferably 50 mol% or more (e.g., 50 to 100 mol%), more preferably 55 to 100 mol%, more preferably 65 to 99.9 mol%, even more preferably 80 to 99 mol%, and particularly preferably 90 to 98 mol%. When the above ratio is 50 mol% or more, the curability of the curable composition is improved and the surface hardness of the hard coat layer is significantly increased. The ratio of each siloxane constituent unit in polyorganosilsesquioxane can be calculated, for example, by the composition of the raw materials or by NMR spectral measurement.

[0084] The proportion of the constituent unit (T3) represented by the above formula (I) to the total amount of siloxane constituent units [total amount of all siloxane constituent units; M units, D units, T units, and Q units] (100 mol%) in silsesquioxane (X) is not particularly limited, but is preferably 50 mol% or more, more preferably 60 to 99 mol%, even more preferably 70 to 98 mol%, even more preferably 80 to 95 mol%, and particularly preferably 85 to 92 mol%. It is presumed that setting the proportion of T3 constituent units to 50 mol% or more makes it easier to form an incomplete cage-like shape with an appropriate molecular weight, and the surface hardness of the hard coat layer tends to improve.

[0085] The ratio (total amount) of the constituent units represented by formula (2) and the constituent units represented by formula (5) in silsesquioxane (X) to the total amount of siloxane constituent units [total amount of all siloxane constituent units; M units, D units, T units, and Q units] (100 mol%) is not particularly limited, but is preferably 0 to 50 mol%, more preferably 0 to 40 mol%, even more preferably 0 to 30 mol%, and particularly preferably 1 to 15 mol%. By setting the above ratio to 50 mol% or less, the proportion of constituent units having cationic polymerizable functional groups can be increased relatively, which improves the curability of the curable composition and tends to increase the surface hardness of the hard coat layer.

[0086] The ratio (total amount) of the constituent units represented by formula (I) and formula (II) in silsesquioxane (X) to the total amount of siloxane constituent units [total amount of all siloxane constituent units; M units, D units, T units, and Q units] (100 mol%) (especially the total ratio of T3 and T2 isomers) is not particularly limited, but is preferably 60 mol% or more (for example, 60 to 100 mol%), more preferably 70 mol% or more, even more preferably 80 mol% or more, and particularly preferably 90 mol% or more. It is presumed that setting the above ratio to 60 mol% or more makes it easier to form an incomplete cage-like shape with an appropriate molecular weight, and the surface hardness of the hard coat layer tends to improve. In particular, it is preferable that the ratio (total amount) of the constituent units represented by formula (1), formula (2), formula (4), and formula (5) is within the above range.

[0087] The number-average molecular weight (Mn) of silsesquioxane (X) as measured by gel permeation chromatography on a standard polystyrene basis is not particularly limited, but is preferably 1000 to 3000, more preferably 1000 to 2800, even more preferably 1100 to 2600, and most preferably 1500 to 2500. A number-average molecular weight of 1000 or more tends to improve the surface hardness of the hard coat layer. It also tends to improve the heat resistance and abrasion resistance of the hard coat layer. On the other hand, a number-average molecular weight of 3000 or less tends to improve compatibility with other components in the curable composition and improve the heat resistance of the hard coat layer.

[0088] The molecular weight dispersibility (Mw / Mn) of silsesquioxane (X) measured by gel permeation chromatography on a standard polystyrene basis is not particularly limited, but is preferably 1.0 to 3.0, more preferably 1.1 to 2.0, even more preferably 1.2 to 1.9, even more preferably 1.3 to 1.8, and most preferably 1.45 to 1.80. A molecular weight dispersibility of 3.0 or less tends to result in higher surface hardness of the hard coat layer. On the other hand, a molecular weight dispersibility of 1.0 or higher (especially 1.1 or higher) tends to make the material more liquid and improve handling.

[0089] The number-average molecular weight and molecular weight dispersion of silsesquioxane (X) can be measured using the following apparatus and conditions. Measuring device: Product name "LC-20AD" (manufactured by Shimadzu Corporation) Columns: Shodex KF-801 x 2, KF-802, and KF-803 (manufactured by Showa Denko Corporation) Measurement temperature: 40℃ Eluent: THF, sample concentration 0.1~0.2% by mass Flow rate: 1mL / min Detector: UV-VIS detector (product name "SPD-20A", manufactured by Shimadzu Corporation) Molecular weight: on a standard polystyrene basis

[0090] Polyorganosylsesquioxanes can be produced by known or conventional methods for producing silsesquioxanes, and are not particularly limited, but for example, they can be produced by hydrolyzing and condensing one or more hydrolyzable silane compounds.

[0091] The content of polyorganosilsesquioxane in the above curable composition is not particularly limited, but is preferably more than 50% by mass (for example, more than 50% by mass and 98% by mass or less) relative to the total amount of curable compounds (100% by mass), more preferably 60 to 96% by mass, even more preferably 70 to 95% by mass, and particularly preferably 80 to 93% by mass. When the above content is more than 50% by mass, the surface hardness of the hard coat layer tends to be further improved. When the above content is 98% by mass or less, other components can be included, and the effects obtained by including these components tend to be further improved. In addition, a curing catalyst can be included, which tends to allow the curing of the curable composition to proceed more efficiently.

[0092] The above curable composition may contain a compound having one or more cationic polymerizable groups and one or more radical polymerizable groups in its molecule (hereinafter sometimes referred to as "compound A"). By containing compound A, the above curable composition can effectively increase the crosslinking density when cured, making it easier to impart high surface hardness, excellent flexibility and flexibility durability to the hard coat layer, and making it less likely for the antifouling performance to deteriorate. Compound A may be used alone or in combination of two or more types.

[0093] Examples of "cationic polymerizable groups" in compound A include epoxy groups, oxetanyl groups, vinyl ether groups, etc., and epoxy groups are preferred from the viewpoint of suppressing a decrease in surface hardness, flexibility, and flexibility durability of the hard coat layer. If compound A has two or more cationic polymerizable groups, these cationic polymerizable groups may be the same or different.

[0094] Examples of "radical polymerizable groups" in compound A include (meth)acryloyl groups and vinyl groups, and (meth)acryloyl groups are preferred from the viewpoint of surface hardness and flexural durability of the hard coat layer. If compound A has two or more radical polymerizable groups, these radical polymerizable groups may be the same or different.

[0095] The number of cationic polymerizable groups that compound A has in one molecule is not limited to one or more, but is preferably 1 to 5, more preferably 1 to 3, and even more preferably 1 or 2. Furthermore, the number of radical polymerizable groups that compound A has in one molecule is not limited to one or more, but is preferably 1 to 5, more preferably 1 to 3, and even more preferably 1 or 2.

[0096] The functional group equivalent of the cationic polymerizable group of compound A is not particularly limited, but is preferably 50 to 500, more preferably 80 to 480, and even more preferably 120 to 450. When the functional group equivalent is 50 or more, it is easy to ensure sufficient bending durability of the hard coat layer. When the functional group equivalent is 500 or less, sufficient surface hardness of the hard coat layer can be ensured. The functional group equivalent of the cationic polymerizable group of compound A can be calculated using the following formula. [Equivalent of cationic polymerizable groups] = [Molecular weight of compound A] / [Number of cationic polymerizable groups in compound A]

[0097] The functional group equivalent of the radical polymerizable group of compound A is not particularly limited, but is preferably 50 to 500, more preferably 80 to 480, and even more preferably 120 to 450. When the functional group equivalent is 50 or more, it is easy to ensure sufficient bending durability of the hard coat layer. When the functional group equivalent is 500 or less, sufficient surface hardness of the hard coat layer can be ensured. The functional group equivalent of the radical polymerizable group of compound A can be calculated using the following formula. [Equivalent of radical polymerizable functional groups] = [Molecular weight of compound A] / [Number of radical polymerizable groups in compound A]

[0098] Compound A specifically includes, for example, 3,4-epoxycyclohexylmethyl (meth)acrylate, glycidyl (meth)acrylate, tripropylene glycol diglycidyl ether di(meth)acrylate (a compound obtained by reacting (meth)acrylic acid with both epoxy groups of tripropylene glycol diglycidyl ether), tripropylene glycol diglycidyl ether half(meth)acrylate (a compound obtained by reacting (meth)acrylic acid with one epoxy group of tripropylene glycol diglycidyl ether), bisphenol A epoxy di(meth)acrylate (a compound obtained by reacting (meth)acrylic acid with both epoxy groups of bisphenol A diglycidyl ether), bisphenol A epoxy half(meth)acrylate (a compound obtained by reacting (meth)acrylic acid or a derivative thereof with one epoxy group of bisphenol A diglycidyl ether), bisphenol F epoxy di(meth)acrylate, bisphenol F epoxy half(meth)acrylate, bisphenol S epoxy di(meth)acrylate, and bisphenol S epoxy half Compounds having an epoxy group and a (meth)acryloyl group in one molecule, such as f(meth)acrylate; compounds having an oxetanyl group and a (meth)acryloyl group in one molecule, such as 3-oxetanylmethyl(meth)acrylate, 3-methyl-3-oxetanylmethyl(meth)acrylate, 3-ethyl-3-oxetanylmethyl(meth)acrylate, 3-butyl-3-oxetanylmethyl(meth)acrylate, 3-hexyl-3-oxetanylmethyl(meth)acrylate; 2-vinyloxyethyl (meth)acrylate, 3-vinyloxyethyl (meth)acrylate Xyxypropyl, 1-methyl-2-vinyloxyethyl (meth)acrylate, 2-vinyloxypropyl (meth)acrylate, 4-vinyloxybutyl (meth)acrylate, 1-methyl-3-vinyloxypropyl (meth)acrylate, 1-vinyloxymethylpropyl (meth)acrylate, 2-methyl-3-vinyloxypropyl (meth)acrylate, 1,1-dimethyl-2-vinyloxyethyl (meth)acrylate, 3-vinyloxybutyl (meth)acrylate, 1-methyl-2-vinyloxypropyl (meth)acrylate, 2-vinyloxybutyl (meth)acrylate,(meth)acrylate 4-vinyloxycyclohexyl, (meth)acrylate 6-vinyloxyhexyl, (meth)acrylate 4-vinyloxymethylcyclohexylmethyl, (meth)acrylate 3-vinyloxymethylcyclohexylmethyl, (meth)acrylate 2-vinyloxycyclohexylmethyl, (meth)acrylate p-vinyloxymethylphenylmethyl, (meth)acrylate m-vinyloxymethylphenylmethyl, (meth)acrylate o-vinyloxymethylphenylmethyl, (meth)acrylate 2-(vinyloxyethoxy)ethyl, (meth ) 2-(vinyloxyisopropoxy)ethyl acrylate, 2-(vinyloxyethoxy)propyl meth)acrylate, 2-(vinyloxyethoxy)isopropyl meth)acrylate, 2-(vinyloxyisopropoxy)propyl meth)acrylate, 2-(vinyloxyisopropoxy)isopropyl meth)acrylate, 2-(vinyloxyethoxyethoxy)ethyl meth)acrylate, 2-(vinyloxyethoxyisopropoxy)ethyl meth)acrylate, (meth)acrylate (Meth) 2-(vinyloxyisopropoxyisopropoxy)ethyl acrylate, (meth) 2-(vinyloxyethoxyethoxy)propyl acrylate, (meth) 2-(vinyloxyethoxyisopropoxy)propyl acrylate, (meth) 2-(vinyloxyisopropoxyethoxy)propyl acrylate, (meth) 2-(vinyloxyisopropoxyisopropoxy)propyl acrylate, (meth) 2-(vinyloxyethoxyethoxy)isopropyl acrylate, (meth) 2-(vinyloxyethoxyisopropoxy)isopropyl acrylate, (meth ) 2-(vinyloxyisopropoxyethoxy)isopropyl acrylate, 2-(vinyloxyisopropoxyisopropoxy)isopropyl meth)acrylate, 2-(vinyloxyethoxyethoxyethoxy)ethyl meth)acrylate, 2-(vinyloxyethoxyethoxyethoxyethoxy)ethyl meth)acrylate, 2-(isopropenoxyethoxy)ethyl meth)acrylate, 2-(isopropenoxyethoxyethoxy)ethyl meth)acrylate, 2-(isopropenoxyethoxyethoxyethoxy)ethyl meth)acrylate,Examples include compounds having a vinyl ether group and a (meth)acryloyl group in one molecule, such as 2-(isopropenoxyethoxyethoxyethoxyethoxy)ethyl (meth)acrylate, polyethylene glycol monovinyl ether (meth)acrylate, and polypropylene glycol monovinyl ether (meth)acrylate.

[0099] From the viewpoint of the flexural durability and surface hardness of the hard coat layer, compound A is preferably a compound having an epoxy group as a cationic polymerizable group and a (meth)acryloyl group as a radical polymerizable group within one molecule. Specifically, 3,4-epoxycyclohexylmethyl (meth)acrylate, glycidyl (meth)acrylate, tripropylene glycol diglycidyl ether half (meth)acrylate, bisphenol A epoxy half (meth)acrylate, bisphenol F epoxy half (meth)acrylate, bisphenol S epoxy half (meth)acrylate, etc. are preferred.

[0100] Compound A can be produced by known methods, for example, by reacting some of the cationic polymerizable groups (e.g., epoxy groups) of a compound having two or more cationic polymerizable groups in one molecule with a carboxylic acid (e.g., acrylic acid, methacrylic acid, etc.) or a derivative thereof that has radical polymerizable groups. Alternatively, commercially available products such as "Light Ester G," "Epoxy Ester 200PA," and "Epoxy Ester 200PA-E5" (all manufactured by Kyoeisha Chemical Co., Ltd.) and "NK OLIGO EA1010N" (manufactured by Shin Nakamura Chemical Industry Co., Ltd.) can be used as Compound A.

[0101] The content of compound A in the above curable composition is not particularly limited, but is preferably 0.05 to 8% by mass, more preferably 0.1 to 5% by mass, and even more preferably 0.2 to 3% by mass, based on the total amount of curable compounds (100% by mass). When the above content is within the above range, the resistance of sebum adhesion to the surface of the hard coat layer is superior.

[0102] The content (amount) of compound A in the above curable composition is not particularly limited, but as solid content, it is preferably 1 to 100 parts by mass, more preferably 1.5 to 75 parts by mass, and even more preferably 2 to 50 parts by mass, per 100 parts by mass of polyorganosilsesquioxane. Increasing the content of compound A to 1 part by mass or more tends to further improve the flexibility and bending durability of the hard coat layer. On the other hand, reducing the content of compound A to 100 parts by mass or less tends to maintain the surface hardness of the hard coat layer.

[0103] Furthermore, the curable composition preferably contains an aliphatic compound having two or more cationic polymerizable groups in its molecule (hereinafter sometimes referred to as compound B), and more preferably contains two or more types of compound B. By including compound B, flexibility can be imparted to the hard coat layer, making it easier to exhibit bending and bending durability. In particular, by including two or more types of compound B, higher flexibility can be exhibited while maintaining surface hardness. Note that compound B is a compound that does not fall under the above polyorganosilsesquioxane and compound A.

[0104] Examples of cationic polymerizable groups include those exemplified in compound A. For example, epoxy groups, oxetanyl groups, vinyl ether groups, etc., and epoxy groups are preferred from the viewpoint of exhibiting the surface hardness, flexibility, and flexibility durability of the hard coat layer, while glycidyl groups are more preferred from the viewpoint of reactivity. The two or more cationic polymerizable groups of compound B may be the same or different.

[0105] Compound B may have two or more cationic polymerizable groups in one molecule, but is not particularly limited. For example, 2 to 5 groups are preferred, more preferably 2 to 3 groups, and even more preferably 2 groups.

[0106] In compound B, "aliphatic compound" refers to an aliphatic compound that does not have a cyclic structure other than the cationic polymerizable group mentioned above. Examples of compound B include glycidyl ethers of alcohols that do not have a cyclic structure of divalent or higher; and glycidyl esters of carboxylic acids of divalent or higher [e.g., adipic acid, sebacic acid, maleic acid, itaconic acid, etc.]. Examples of alcohols that do not have a cyclic structure of divalent or higher include divalent alcohols such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, polyethylene glycol, and polypropylene glycol; and polyhydric alcohols of trivalent or higher such as glycerin, diglycerin, erythritol, trimethylolethane, trimethylolpropane, pentaerythritol, dipentaerythritol, and sorbitol. Furthermore, the alcohol with a hydride of 2 or more may be a polyether polyol, polyester polyol, polycarbonate polyol, polyolefin polyol, etc.

[0107] Compound B is preferably a compound having two cationic polymerizable functional groups at both ends of the above aliphatic compound, and specifically, a compound represented by the following formula (A) is preferred. [ka]

[0108] In the above formula (A), M represents a linear or branched alkylene group having 2 to 10 carbon atoms or an ethylene glycol group having 5 to 15 repeating units. Examples of linear or branched alkylene groups having 2 to 10 carbon atoms include ethylene groups, propylene groups, trimethylene groups, tetramethylene groups, pentamethylene groups, hexamethylene groups, decamethylene groups, etc. Among these, a linear or branched alkylene group having 3 to 8 carbon atoms is preferred as M from the viewpoint of improving the surface hardness, flexibility, and bending durability of the hard coat-less film, as well as preventing a decrease in antifouling performance, a linear alkylene group having 5 to 7 carbon atoms is more preferred, and a linear alkylene group having 6 carbon atoms (hexamethylene group) is even more preferred. Furthermore, examples of ethylene glycol groups with 5 to 15 repeating units include hexaethylene glycol groups, nonaethylene glycol groups, and decaethylene glycol groups. Nonaethylene glycol groups are preferred in order to further improve flexibility while maintaining surface hardness. When compound B contains two or more types, it is preferable to include both a linear or branched alkylene group with 2 to 10 carbon atoms and an ethylene glycol group with 5 to 15 repeating units.

[0109] In the above formula (A), E 1 and E 2 The groups, which are identical or different, exhibit cationic polymerizable functional groups, and which improve reactivity, surface hardness of the hard coat layer, flexibility, and bending durability, as well as preventing a decrease in antifouling performance, are preferably groups represented by the following formula (E). [ka]

[0110] In formula (E), R A R represents a linear or branched alkylene group having 1 to 6 carbon atoms. Examples of linear or branched alkylene groups having 1 to 6 carbon atoms include methylene, methylmethylene, dimethylmethylene, ethylene, propylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, and decamethylene groups. Among these, RA As such, linear alkylene groups having 1 to 4 carbon atoms are preferred, more preferably methylene groups and ethylene groups, and even more preferably methylene groups, from the viewpoint of improving reactivity, surface hardness of the hard coat layer, flexibility, and flexibility durability, as well as preventing a decrease in antifouling performance. B This is a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms, preferably a hydrogen atom or a methyl group, and more preferably a hydrogen atom.

[0111] The functional group equivalent of the cationic polymerizable group of compound B is not particularly limited, but is preferably 50 to 500, more preferably 80 to 480, and even more preferably 120 to 450. When the functional group equivalent is 50 or more, it is easy to ensure sufficient bending durability of the hard coat layer. When the functional group equivalent is 500 or less, sufficient surface hardness of the hard coat layer can be achieved. Furthermore, when compound B contains two or more types, the epoxy equivalent of at least one type of compound B is preferably 50 to 200, more preferably 80 to 180, and even more preferably 100 to 160. Furthermore, the functional group equivalent of another type of compound B is preferably more than 200 to 500, more preferably 220 to 450, and even more preferably 240 to 400. By combining compound B having functional group equivalents within the above ranges, higher flexibility can be achieved while maintaining surface hardness. The functional group equivalent of the cationic polymerizable group of compound B can be calculated using the following formula. [Equivalent of cationic polymerizable groups] = [Molecular weight of compound B] / [Number of cationic polymerizable groups in compound B]

[0112] Hereafter, in this specification, compound B with a functional group equivalent of 50 to 200 may be referred to as "short-chain compound B," and compound B with a functional group equivalent of more than 200 to 500 may be referred to as "long-chain compound B."

[0113] Compound B specifically includes, for example, ethylene glycol diglycidyl ether, 1,3-propanediol diglycidyl ether, 2-methyl-1,3-propanediol diglycidyl ether, 2-butyl-2-ethyl-1,3-propanediol diglycidyl ether, 1,4-butanediol diglycidyl ether (tetramethylene glycol diglycidyl ether), neopentyl glycol diglycidyl ether, 3-methyl-2,4-pentanediol diglycidyl ether, 2,4-pentanediol diglycidyl ether, 1,5-pentanediol diglycidyl ether (pentamethylene glycol diglycidyl ether), 3-methyl-1,5-pentanediol diglycidyl ether, 2-methyl-2,4-pentanediol diglycidyl ether, and 2,4-diethyl-1,5-pentanediol. Examples include alkylene glycol diglycidyl ethers (alkanediol diglycidyl ethers) such as diol diglycidyl ether, 1,6-hexanediol diglycidyl ether (hexamethylene glycol diglycidyl ether), 1,7-heptanediol diglycidyl ether, 3,5-heptanediol diglycidyl ether, 1,8-octanediol diglycidyl ether, 2-methyl-1,8-octanediol diglycidyl ether, and 1,9-nonanediol diglycidyl ether, as well as (poly)alkylene glycol diglycidyl ethers such as diethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, triethylene glycol diglycidyl ether, hexaethylene glycol diglycidyl ether, and nonaethylene glycol diglycidyl ether. In particular, compound B preferably contains diol diglycidyl ether and (poly)alkylene glycol diglycidyl ether, more preferably contains diol diglycidyl ether, which is compound B with a short chain length, and (poly)alkylene glycol diglycidyl ether, which is compound B with a long chain length, and is especially preferably a combination of nonaethylene glycol diglycidyl ether and 1,6-hexanediol diglycidyl ether.

[0114] Commercially available products of compound B include the product names "Epolite 40E," "Epolite 100E," "Epolite 200E," "Epolite 400E," "Epolite 1600," and "Epolite 1600N" (manufactured by Kyoeisha Chemical Co., Ltd.), and the product name "YH-300" (manufactured by Nippon Steel Chemical & Material Co., Ltd.).

[0115] The content of compound B in the above curable composition is not particularly limited, but is preferably 1 to 20% by mass, more preferably 3 to 15% by mass, and even more preferably 5 to 13% by mass, based on the total amount of curable compounds (100% by mass). When the above content is within the above range, the flexibility of the transparent laminate becomes more appropriate.

[0116] The content of compound B is not particularly limited, but is preferably 1 to 20 parts by mass, more preferably 3 to 17 parts by mass, and even more preferably 5 to 15 parts by mass, per 100 parts by mass of the polyorganosilsesquioxane, as solid content. When the content is within the above range, the flexibility of the transparent laminate becomes more appropriate.

[0117] Furthermore, when compound B contains both short-chain compound B and long-chain compound B, the content of long-chain compound B is preferably 35 to 95% by mass, more preferably 50 to 90% by mass, and even more preferably 65 to 87% by mass, relative to the total amount of compound B (100% by mass). When the content of long-chain compound B in compound B is 35% by mass or more, it becomes easier to exhibit flexibility. Also, when it is 95% by mass or less, the surface hardness can be sufficiently high.

[0118] The above curable composition preferably contains a curing catalyst. The curing catalyst is a compound that can initiate or accelerate the polymerization reaction of curable compounds such as the polyorganosylsesquioxane, compound A, and compound B. The curing catalyst may be used alone or in combination of two or more types.

[0119] The curing catalyst is selected based on the type of curable functional group present in the curable compound, but cationic polymerization initiators and / or radical polymerization initiators are preferred. The cationic polymerization initiator is a compound that generates cationic species by heat or irradiation with active energy rays, thereby initiating the curing reaction of the curable compound.

[0120] Examples of the cationic polymerization initiators mentioned above include photocatalytic cationic polymerization initiators (photoacid generators) and thermal cationic polymerization initiators (thermal acid generators).

[0121] As the above-mentioned photocationic polymerization initiator, known or conventional photocationic polymerization initiators can be used, for example, sulfonium salts (salts of sulfonium ions and anions), iodonium salts (salts of iodonium ions and anions), selenium salts (salts of selenium ions and anions), ammonium salts (salts of ammonium ions and anions), phosphonium salts (salts of phosphonium ions and anions), and salts of transition metal complex ions and anions.

[0122] Examples of the above sulfonium salts include triphenylsulfonium salt, tri-p-tolylsulfonium salt, tri-o-tolylsulfonium salt, tris(4-methoxyphenyl)sulfonium salt, 1-naphthyldiphenylsulfonium salt, 2-naphthyldiphenylsulfonium salt, tris(4-fluorophenyl)sulfonium salt, tri-1-naphthylsulfonium salt, tri-2-naphthylsulfonium salt, tris(4-hydroxyphenyl)sulfonium salt, diphenyl[4-(phenylthio)phenyl]sulfonium salt, and 4-(p-tolylthio)phenyldi-(p-phenyl)sulfonium salt. Examples include triarylsulfonium salts such as methylsulfonium salt; diarylsulfonium salts such as diphenylphenacylsulfonium salt, diphenyl-4-nitrophenacylsulfonium salt, diphenylbenzylsulfonium salt, and diphenylmethylsulfonium salt; monoarylsulfonium salts such as phenylmethylbenzylsulfonium salt, 4-hydroxyphenylmethylbenzylsulfonium salt, and 4-methoxyphenylmethylbenzylsulfonium salt; and trialkylsulfonium salts such as dimethylphenacylsulfonium salt, phenacyltetrahydrothiophenium salt, and dimethylbenzylsulfonium salt.

[0123] Examples of the above-mentioned diphenyl[4-(phenylthio)phenyl]sulfonium salts include diphenyl[4-(phenylthio)phenyl]sulfonium tetrakis(pentafluorophenyl)borate and diphenyl[4-(phenylthio)phenyl]sulfonium hexafluorophosphate. Commercially available products such as "CPI-100P" (manufactured by Sunapro Co., Ltd., a 50% propylene carbonate solution of diphenyl[4-(phenylthio)phenyl]sulfonium hexafluorophosphate) can also be used.

[0124] Examples of the iodonium salts mentioned above include the product name "RHODORSIL PHOTOINITIATOR 2074" (manufactured by Rhodia Japan Co., Ltd., tetrakis(pentafluorophenyl)borate-[(1-methylethyl)phenyl](methylphenyl)iodonium), the product name "WPI-124" (manufactured by Wako Pure Chemical Industries, Ltd.), diphenyliodonium salt, di-p-tolyliodonium salt, bis(4-dodecylphenyl)iodonium salt, and bis(4-methoxyphenyl)iodonium salt.

[0125] Examples of the selenium salts mentioned above include triarylselenium salts such as triphenylselenium salt, tri-p-tolylselenium salt, tri-o-tolylselenium salt, tris(4-methoxyphenyl)selenium salt, and 1-naphthyldiphenylselenium salt; diarylselenium salts such as diphenylphenacylselenium salt, diphenylbenzylselenium salt, and diphenylmethylselenium salt; monoarylselenium salts such as phenylmethylbenzylselenium salt; and trialkylselenium salts such as dimethylphenacylselenium salt.

[0126] Examples of the above ammonium salts include tetraalkylammonium salts such as tetramethylammonium salt, ethyltrimethylammonium salt, diethyldimethylammonium salt, triethylmethylammonium salt, tetraethylammonium salt, trimethyl-n-propylammonium salt, and trimethyl-n-butylammonium salt; pyrrolidium salts such as N,N-dimethylpyrrolidium salt and N-ethyl-N-methylpyrrolidium salt; imidazolinium salts such as N,N'-dimethylimidazolinium salt and N,N'-diethylimidazolinium salt; and N,N'-dimethyltetrahydropyrimidium salt and N,N'-diethyl Examples include tetrahydropyrimidium salts such as trahydropyrimidium salt; morpholinium salts such as N,N-dimethylmorpholinium salt and N,N-diethylmorpholinium salt; piperidinium salts such as N,N-dimethylpiperidinium salt and N,N-diethylpiperidinium salt; pyridinium salts such as N-methylpyridinium salt and N-ethylpyridinium salt; imidazolium salts such as N,N'-dimethylimidazolium salt; quinolium salts such as N-methylquinolium salt; isoquinolium salts such as N-methylisoquinolium salt; thiazonium salts such as benzylbenzothiazonium salt; and acridium salts such as benzylacridium salt.

[0127] Examples of the phosphonium salts mentioned above include tetraarylphosphonium salts such as tetraphenylphosphonium salt, tetra-p-tolylphosphonium salt, and tetrakis(2-methoxyphenyl)phosphonium salt; triarylphosphonium salts such as triphenylbenzylphosphonium salt; and tetraalkylphosphonium salts such as triethylbenzylphosphonium salt, tributylbenzylphosphonium salt, tetraethylphosphonium salt, tetrabutylphosphonium salt, and triethylphenacylphosphonium salt.

[0128] Examples of the above transition metal complex ion salts include (η 5 -cyclopentadienyl)(η 6 -toluene)Cr + , (η 5 -cyclopentadienyl)(η 6 -Xylene)Cr+ salts of chromium complex cations such as; (η 5 -cyclopentadienyl)(η 6 -toluene)Fe + , (η 5 -cyclopentadienyl)(η 6 -xylene)Fe + and salts of iron complex cations such as etc.

[0129] Examples of the anions constituting the above salts include, for example, PF6 - , BF4 - , (C6F5)4B - , (C6F5)4Ga - , sulfonic acid anions (trifluoromethanesulfonic acid anion, pentafluoroethanesulfonic acid anion, methanesulfonic acid anion, benzenesulfonic acid anion, p-toluenesulfonic acid anion, etc.), perhalogenate ions, halogenated sulfonate ions, sulfate ions, carbonate ions, aluminate ions, carboxylate ions, arylborate ions, thiocyanate ions, nitrate ions, etc.

[0130] Examples of the above thermal cationic polymerization initiators include, for example, arylsulfonium salts, aryliodonium salts, allene-ion complexes, quaternary ammonium salts, aluminum chelates, boron trifluoride amine complexes, etc. Further, examples of the anions constituting the above salts include the same ones as those in the anions of the photo cationic polymerization initiator.

[0131] Examples of the above-mentioned arylsulfonium salts include pentafluorophenylborate and hexafluorophosphate. In the curable composition of this disclosure, commercially available products such as "SP-66" and "SP-77" (both manufactured by ADEKA Corporation); "San-Aid SI-150L", "San-Aid SI-110", "San-Aid SI-360", "San-Aid SI-300", "San-Aid SI-B4", "San-Aid SI-B5", "San-Aid SI-B3", "San-Aid SI-B3A", "San-Aid SI-B7", and "San-Aid SI-B2A" (all manufactured by Sanshin Chemical Industry Co., Ltd.) can be used. Examples of the above-mentioned aluminum chelates include ethyl acetate aluminum diisopropylate and aluminum tris(ethyl acetate). Examples of the boron trifluoride amine complexes include boron trifluoride monoethylamine complex, boron trifluoride imidazole complex, and boron trifluoride piperidine complex.

[0132] The above-mentioned radical polymerization initiators are compounds that generate radicals upon heat or irradiation with active energy rays, thereby initiating the curing reaction of curable compounds.

[0133] Examples of the radical polymerization initiators mentioned above include photoradical polymerization initiators and thermal radical polymerization initiators. Examples of the photoradical polymerization initiators include alkylphenone-based photoradical polymerization initiators, acylphosphine oxide-based photoradical polymerization initiators, oxime ester-based photoradical polymerization initiators, and α-hydroxyketone-based photoradical polymerization initiators.

[0134] Examples of the alkylphenone-based photoradical polymerization initiators include 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-[4-(4-morpholinyl)phenyl]-1-butanone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, benzophenone, methylbenzophenone, o-benzoylbenzoic acid, benzoyl ethyl ether, 2,2-diethoxyacetophenone, 2 Examples include 4-diethylthioxanthone, diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide, ethyl-(2,4,6-trimethylbenzoyl)phenylphosphine, 4,4'-bis(diethylamino)benzophenone, 1-hydroxycyclohexylphenyl ketone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, and oligomers of 2-hydroxy-1-(4-isopropenylphenyl)-2-methylpropan-1-one.

[0135] Examples of the above-mentioned acylphosphine oxide-based photoradical polymerization initiators include 2,4,6-trimethylbenzoyldiphenylphosphine oxide and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide.

[0136] Examples of the above-mentioned oxime ester-based photoradical polymerization initiators include 1-[4-(phenylthio)phenyl]-1,2-octanedione 2-(O-benzoyl oxime) and 1-[6-(2-methylbenzoyl)-9-ethyl-9H-carbazol-3-yl]ethanone O-acetyl oxime.

[0137] Examples of the above-mentioned α-hydroxyketone-based photoradical polymerization initiators include benzoin, benzoin methyl ether, benzoin butyl ether, 1-hydroxycyclohexylphenyl ketone, 1-phenyl-2-hydroxy-2-methylpropan-1-one, 1-(4-i-propylphenyl)-2-hydroxy-2-methylpropan-1-one, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)ketone, and 1-hydroxycyclohexylphenyl ketone.

[0138] The content (amount) of the curing catalyst in the above curable composition is not particularly limited, but is preferably 0.01 to 10 parts by mass, more preferably 0.03 to 5 parts by mass, and even more preferably 0.05 to 3 parts by mass, per 100 parts by mass of the total amount of curable compound. When the content of the curing catalyst is 0.01 parts by mass or more, the curing reaction can be carried out efficiently and sufficiently, and the surface hardness of the hard coat layer tends to be further improved. On the other hand, when the content of the curing catalyst is 10 parts by mass or less, the shelf life of the curable composition is improved and discoloration of the cured product tends to be suppressed.

[0139] The content (amount) of the cationic polymerization initiator in the above curable composition is not particularly limited, but is preferably 0.05 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, even more preferably 0.15 to 3 parts by mass, and particularly preferably 0.2 to 2 parts by mass, per 100 parts by mass of the total amount of curable compound. When the content is 0.05 parts by mass or more, the curing reaction can proceed efficiently and sufficiently, and the surface hardness of the cured product tends to improve further. When the content is 10 parts by mass or less, the shelf life of the curable composition improves and discoloration of the cured product tends to be suppressed.

[0140] The content (amount) of the radical polymerization initiator in the curable composition described above is not particularly limited, but is preferably 0.1 to 5 parts by mass, more preferably 0.3 to 3 parts by mass, and even more preferably 0.5 to 2 parts by mass, per 100 parts by mass of the total amount of curable compound. When the content is 0.1 parts by mass or more, the curing reaction can proceed efficiently and sufficiently, and the surface hardness of the cured product tends to improve further. When the content is 5 parts by mass or less, the shelf life of the curable composition improves, and discoloration of the cured product tends to be suppressed.

[0141] The above curable composition preferably contains a radical-curable polyorganosiloxane as a leveling agent. Using the above radical-curable polyorganosiloxane improves the smoothness of the hard coat layer surface, provides excellent resistance to sebum adhesion, and makes the hard coat layer surface less prone to fingerprints. Furthermore, the above active energy ray-curable polyorganosiloxane is preferably not a compound that falls under the category of PFAS, and in this case, it exhibits the above effects while not being a compound that falls under the category of PFAS. Since the above radical-curable polyorganosiloxane has radical curability, it also falls under the category of the above curable compound. The above radical-curable polyorganosiloxane may be used alone or two or more types may be used.

[0142] The above-mentioned radical-curable polyorganosiloxane has a radical-polymerizable functional group within its molecule. Examples of such radical-curable functional groups include photo-radical polymerizable functional groups.

[0143] Examples of the above-mentioned photoradical polymerizable functional groups include (meth)acryloyl groups, (meth)acrylamide groups, vinyl groups, and vinylthio groups. Among these, (meth)acryloyl groups are preferred.

[0144] In the above-mentioned radical-curable polyorganosiloxane, linear polyorganosiloxanes are preferred as polyorganosiloxanes from the viewpoint of exhibiting greater effectiveness as leveling agents.

[0145] The content of the radical-curable polyorganosiloxane is not particularly limited, but is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 3 parts by mass, and even more preferably 0.1 to 2 parts by mass, per 100 parts by mass of the polyorganosilsesquioxane, as solid content.

[0146] The above curable composition preferably contains an antioxidant. The inclusion of an antioxidant in the curable composition tends to further improve the preservation of the hard coat layer. One type of antioxidant may be used, or two or more types may be used.

[0147] As antioxidants, known or conventional antioxidants can be used and are not particularly limited, but examples include phenolic antioxidants, hindered amine antioxidants, phosphorus antioxidants, sulfur antioxidants, and the like.

[0148] Examples of the above-mentioned phenolic antioxidants include monophenols such as 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-p-ethylphenol, and stearyl-β-(3,5-di-t-butyl-4-hydroxyphenyl)propionate; 2,2'-methylenebis(4-methyl-6-t-butylphenol), 2,2'-methylenebis(4-ethyl-6-t-butylphenol), 4,4'-thiobis(3-methyl-6-t-butylphenol), 4,4'-butylidenebis(3-methyl-6-t-butylphenol), and 3,9-bis[1,1-dimethyl-2-{β-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy}ethyl]2,4,8 Examples include bisphenols such as ,10-tetraoxaspiro[5.5]undecane; 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, tetrakis[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane, bis[3,3'-bis-(4'-hydroxy-3'-t-butylphenyl)butyric acid]glycol ester, 1,3,5-tris(3',5'-di-t-butyl-4'-hydroxybenzyl)-s-triazine-2,4,6-(1H,3H,5H)trione, and high molecular weight phenols such as tocopherol.

[0149] Examples of the above-mentioned hindered amine antioxidants include bis(1,2,2,6,6-pentamethyl-4-piperidyl)[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]butylmalonate, bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, methyl-1,2,2,6,6-pentamethyl-4-piperidyl sebacate, and 4-benzoyloxy-2,2,6,6-tetramethylpiperidine.

[0150] Examples of the phosphorus-based antioxidants mentioned above include triphenyl phosphite, diphenylisodecyl phosphite, phenyldiisodecyl phosphite, tris(nonylphenyl) phosphite, diisodecylpentaerythritol phosphite, tris(2,4-di-t-butylphenyl) phosphite, cyclic neopentanetetraylbis(octadecyl) phosphite, cyclic neopentanetetraylbis(2,4-di-t-butylphenyl) phosphite, and cyclic neopentanetetraylbis(2 Phosphates such as ,4-di-t-butyl-4-methylphenyl) phosphite and bis[2-t-butyl-6-methyl-4-{2-(octadecyloxycarbonyl)ethyl}phenyl]hydrogen phosphite; and oxaphosphaphenanthrene oxides such as 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and 10-(3,5-di-t-butyl-4-hydroxybenzyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide.

[0151] Examples of the above-mentioned sulfur-based antioxidants include dodecanethiol, dilauryl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, and distearyl-3,3'-thiodipropionate.

[0152] When the above curable composition contains an antioxidant, the content ratio of the antioxidant is not particularly limited, but is preferably 0.05 to 5 parts by mass, and more preferably 0.1 to 1 part by mass, relative to the total amount of the curable compound (100 parts by mass). If the antioxidant content is 0.05 parts by mass or more, sufficient stability can be achieved. Furthermore, if the antioxidant content is 5 parts by mass or less, discoloration of the hard coat layer can be suppressed.

[0153] If the above curable composition contains an antioxidant, its content is not particularly limited, but is preferably 0.05 to 5 parts by mass, and more preferably 0.1 to 3 parts by mass, per 100 parts by mass of polyorganosilsesquioxane. If the antioxidant content is 0.05 parts by mass or more, sufficient stability can be achieved. Furthermore, if the antioxidant content is 5 parts by mass or less, discoloration of the hard coat layer can be suppressed.

[0154] The above curable composition may further contain a solvent. The solvent is not particularly limited as long as it can dissolve the above polyorganosilsesquioxane and any additives used as needed, and does not inhibit polymerization. One solvent may be used, or two or more solvents may be used.

[0155] The solvent used is preferably one that can provide fluidity suitable for application to the hard coat layer and can be easily removed by heating at a temperature that suppresses the progression of polymerization. It is also preferable to use a solvent with a boiling point (at 1 atm) of 170°C or lower (for example, aromatic solvents such as toluene, xylene, and mesitylene; esters such as butyl acetate; ketones such as methyl isobutyl ketone and cyclohexanone; ethers such as propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate).

[0156] The above solvent is preferably used in a range where the concentration of non-volatile components in the curable composition is, for example, 5 to 100% by mass, more preferably 10 to 80% by mass, and particularly preferably 20 to 70% by mass, in order to achieve excellent coatability. However, the amount added should be selected as the optimal amount to adjust the viscosity so that an appropriate film thickness can be achieved, and is not limited to the above range. In other words, if the amount of solvent used is excessive, the viscosity of the curable composition tends to become low, making it difficult to form a coating film of an appropriate thickness. On the other hand, if the amount of solvent used is too little, the viscosity of the curable composition tends to become too high, making it difficult to apply uniformly to the substrate.

[0157] The above curable composition may further contain, as other components, inorganic fillers such as precipitated silica, wet silica, fumed silica, calcined silica, titanium dioxide, alumina, glass, quartz, aluminosilicate, iron oxide, zinc oxide, calcium carbonate, carbon black, silicon carbide, silicon nitride, and boron nitride; inorganic fillers obtained by treating these fillers with organosilicon compounds such as organohalosilane, organoalkoxysilane, and organosilazane; fine powders of organic resins such as silicone resin, epoxy resin, and fluororesin; fillers such as conductive metal powders such as silver and copper; curing aids; stabilizers (light stabilizers, heat stabilizers, heavy metal deactivators, etc.); and ultraviolet absorbers (triazine-based ultraviolet absorbers, benzotriazole). The product may contain conventional additives such as UV absorbers (including benzophenone-based UV absorbers, oxybenzophenone-based UV absorbers, salicylic acid ester-based UV absorbers, and cyanoacrylate-based UV absorbers), flame retardants (phosphorus-based flame retardants, halogen-based flame retardants, inorganic flame retardants, etc.), flame retardant additives, reinforcing materials (other fillers, etc.), nucleating agents, coupling agents (silane coupling agents, etc.), lubricants, waxes, plasticizers, mold release agents, impact resistance modifiers, color modifiers, transparency modifiers, rheology modifiers (flow modifiers, etc.), processability modifiers, colorants (dyes, pigments, etc.), antistatic agents, dispersants, surface modifiers (slip agents, etc.), matting agents, defoaming agents, anti-foaming agents, antibacterial agents, preservatives, viscosity modifiers, thickeners, photosensitizers, and foaming agents. The above other components may be used individually or in combination of two or more types. The content of the above-mentioned other components is not particularly limited, but is preferably 100 parts by mass or less, more preferably 30 parts by mass or less (for example, 0.01 to 30 parts by mass), and even more preferably 10 parts by mass or less (for example, 0.1 to 10 parts by mass), per 100 parts by mass of the total amount of the curable compound.

[0158] Furthermore, it is preferable that the above-mentioned curable composition does not contain compounds that fall under the category of PFAS. Having the above composition makes it possible to avoid the use of PFAS and comply with PFAS regulations.

[0159] The above curable composition is not particularly limited, but can be prepared by stirring and mixing each of the above components at room temperature or, if necessary, while heating. The above curable composition can be used as a one-component composition in which the components are pre-mixed and used as is, or it can be used as a multi-component (e.g., two-component) composition in which two or more components that have been stored separately are mixed in a predetermined ratio before use.

[0160] The above curable composition is not particularly limited, but it is preferably a liquid at room temperature (about 25°C). More specifically, the viscosity of the above curable composition at 25°C when diluted with 20% solvent [particularly a curable composition solution in which the proportion of methyl isobutyl ketone is 20% by mass] is preferably 300 to 20000 mPa·s, more preferably 500 to 10000 mPa·s, and even more preferably 1000 to 8000 mPa·s. Setting the viscosity to 300 mPa·s or higher tends to improve the curing of the cured product (coating film). On the other hand, setting the viscosity to 20000 mPa·s or lower makes the preparation and handling of the curable composition easier, and tends to reduce the likelihood of air bubbles remaining in the cured product (coating film). The viscosity of the above-mentioned curable composition is measured using a viscometer (product name "MCR301," manufactured by Anton Paar) under the following conditions: amplitude 5%, frequency 0.1-100 (1 / s), and temperature 25°C.

[0161] The hard coat layer described above can be manufactured in accordance with known or conventional methods for manufacturing hard coat layers, and the manufacturing method is not particularly limited. For example, it can be manufactured by coating the curable composition onto at least one surface of the substrate (the undercoat layer surface if an undercoat layer is formed), removing the solvent by drying as necessary, and then curing the curable composition (curable composition layer). The coating method for the curable composition and the conditions for curing are not particularly limited and can be appropriately selected from, for example, the conditions described below.

[0162] Conventional coating methods can be used for coating and curing the hard coat layer described above. Specifically, the same method as the coating method for the undercoat layer described above can be used. When irradiating with ultraviolet light for curing the hard coat layer, for example, the cumulative irradiation dose should be 1 to 5000 mJ / cm². 2 It is preferable to keep it to a certain degree.

[0163] The specific curing conditions are not particularly limited, but for example, the curable composition is first heat-treated (pre-baked) at a temperature of preferably 60°C or higher, more preferably 120°C or higher, even more preferably 150°C or higher, for preferably 10 seconds or more, more preferably 30 seconds or more, and even more preferably 60 seconds or more, and then irradiated with ultraviolet light (irradiation conditions (irradiation amount): preferably 300 mJ / cm²). 2 More than; Irradiation intensity: 100mW / cm 2 (As described above), finally, the product can be cured by heat treatment (aging) at a temperature of 120°C or higher, preferably for 0.5 hours or more. However, the curing conditions are not limited to this range, and the pre-bake temperature and time, and the aging temperature and time can be appropriately selected depending on the solvent used, and the ultraviolet irradiation conditions can also be appropriately selected depending on the curing agent used.

[0164] As described above, the curable composition can be applied and cured to form a hard coat layer with high surface hardness and toughness. The transparent laminate containing the hard coat layer thus produced has excellent flexibility and bending durability, while also improving the surface hardness of the hard coat layer.

[0165] To further improve the recoatability of the hard coat layer, surface treatments such as corona discharge treatment, plasma discharge treatment, ozone exposure treatment, and excimer treatment may be applied to modify the surface of the hard coat layer by corona discharge irradiation. Among these, corona discharge treatment is more preferred because it can easily improve recoatability.

[0166] Corona discharge processing is a process that processes the surface of a hard coat layer by generating a non-uniform electric field around a pointed electrode (needle electrode) and creating a sustained discharge. Plasma discharge processing is a process that processes the surface of a hard coat layer by generating activated positively and negatively charged particles by discharging in the atmosphere. Ozone exposure processing is a process that processes the surface of a hard coat layer by generating ozone, for example, by irradiating with ultraviolet light using a low-pressure mercury lamp in the presence of oxygen. Excimer processing is a process that processes the surface of a hard coat layer by irradiating with ultraviolet light or laser light using an excimer lamp in a vacuum.

[0167] The haze of the hard coat layer described above is preferably 1% or less, more preferably 0.7% or less, and even more preferably 0.5% or less. The lower limit of the haze is, for example, 0.1%. A haze level of 1% or less tends to make the material suitable for applications requiring high transparency.

[0168] The thickness of the hard coat layer is preferably 5 to 100 μm, and more preferably 10 to 70 μm. A hard coat layer thickness of 5 μm or more allows for sufficient surface hardness. A thickness of 100 μm or less facilitates flexibility. When the hard coat layer is formed on both sides of the substrate, at least one of the hard coat layers is preferably 5 μm or more, and more preferably 10 μm or more. From the viewpoint of achieving flexibility, both hard coat layers are preferably 50 μm or less, and more preferably 45 μm or less.

[0169] [Image display device] One embodiment of the present disclosure is an image display device equipped with the transparent laminate described above. In the image display device, the transparent laminate is arranged such that, for example, the hard coat layer constitutes the surface on the viewing side. The image display device is not particularly limited and examples include organic electroluminescent display devices, inorganic electroluminescent display devices, liquid crystal display devices, etc. Because the surface of the hard coat layer of the display device has sufficient surface hardness, it is less prone to scratches and has excellent touch properties. Furthermore, because the image display device has excellent flexibility and bending durability, it can also be used as a flexible display that can be wound up or the like. Moreover, because it has sufficient surface hardness, flexibility, and bending durability, it can also be suitably used as a flexible device including the image display device.

[0170] Each embodiment disclosed herein can be combined with any other features disclosed herein. Furthermore, each configuration and combination thereof in each embodiment is an example, and additions, omissions, and other modifications are permitted as appropriate, without departing from the spirit of this disclosure. This disclosure is not limited by the embodiments, but is limited only by the scope of the claims. [Examples]

[0171] An embodiment of this disclosure will be described in more detail below based on examples.

[0172] Manufacturing Example 1 (Manufacturing of polyorganosilsesquioxane) A 1000 ml flask (reaction vessel) equipped with a thermometer, stirrer, reflux condenser, and nitrogen inlet tube was charged with 277.2 mmol (68.30 g) of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3.0 mmol (0.56 g) of phenyltrimethoxysilane, and 275.4 g of acetone under a nitrogen stream, and the temperature was raised to 50°C. To the mixture obtained in this way, 7.74 g of 5% potassium carbonate aqueous solution (2.8 mmol as potassium carbonate) was added over 5 minutes, and then 2800.0 mmol (50.40 g) of water was added over 20 minutes. No significant temperature increase occurred during the addition. Subsequently, the polycondensation reaction was carried out at 50°C under a nitrogen stream for 5 hours. Subsequently, while the reaction solution was cooled, 137.70 g of methyl isobutyl ketone and 100.60 g of 5% saline solution were added. This solution was transferred to a 1 L separatory funnel, and another 137.70 g of methyl isobutyl ketone was added, followed by washing with water. After separation, the aqueous layer was removed, and the lower layer was washed with water until it became neutral. The upper layer was then separated, and the solvent was removed from the upper layer under conditions of 1 mmHg and 50°C, yielding 75.18 g of a colorless, transparent, liquid product (epoxy group-containing low molecular weight polyorganosilsesquioxane: silsesquioxane) containing 23% by mass of methyl isobutyl ketone. Furthermore, analysis of the product revealed that the number-average molecular weight was 2235 and the molecular weight dispersion was 1.54. 29 The ratio of T2 to T3 isomers [T3 / T2] calculated from the Si-NMR spectrum was 11.9. 1 H-NMR, 29 Confirmation was performed using Si-NMR. The molecular weight of the product was measured using a Shimadzu LC-20AD pump, Shodex RI-504 detector, Shodex GPC KF-602 and KF-603 columns, Shodex GPC KF-G guard column, THF solvent, and at 40°C. The ratio of T2 to T3 isomers [T3 / T2] in the product was measured using a JEOL ECA500 (500MHz). 29 The measurement was performed using Si-NMR spectroscopy.

[0173] (Preparation of hard coat agent) A hard coat agent was prepared by mixing the silsesquioxane mentioned above with the materials in the proportions shown in Table 1. The percentages shown in Tables 1-7 represent the proportion of each component; the values ​​for silsesquioxane (77% by mass of active ingredient) and RS-57 (20% by mass of active ingredient) are for the solution, while the values ​​for the other components are for the active ingredients.

[0174] [Table 1]

[0175] Example 1 A 5 μm thick layer of "CELV B0955" (manufactured by Daicel Corporation) was applied as a primer to a chemically strengthened UTG (manufactured by Nippon Electric Glass Co., Ltd., 90 μm thick) using a wire bar #5, and then heated with a high-pressure mercury lamp at 300 mJ / cm². 2 The hard coat was cured by irradiating it with ultraviolet light at the specified intensity. Next, the hard coat was applied to the primer using a wire bar #30 so that the hard coat thickness after curing was 25 μm, and then left in an 80°C oven for 1 minute, and then in a 120°C oven for 2 minutes. Next, a high-pressure mercury lamp was used to irradiate it with 300 mJ / cm³. 2 A hard coat layer was formed by irradiating with ultraviolet light at a specified intensity. Then, the material was left in a 120°C oven for 60 minutes to produce the transparent laminate of Example 1.

[0176] Example 2 The transparent laminate of Example 2 was prepared in the same manner as in Example 1, except that the hard coating agent with the mixing ratio shown in Table 2 was used.

[0177] [Table 2]

[0178] Example 3 The transparent laminate of Example 3 was prepared in the same manner as in Example 1, except that the hard coating agent with the mixing ratio shown in Table 3 was used.

[0179] [Table 3]

[0180] Example 4 The transparent laminate of Example 4 was prepared in the same manner as in Example 1, except that the hard coating agent used was in the proportions shown in Table 4.

[0181] [Table 4]

[0182] Example 5 The transparent laminate of Example 5 was prepared in the same manner as in Example 1, except that the hard coating agent with the mixing ratio shown in Table 5 was used.

[0183] [Table 5]

[0184] Comparative Example 1 A transparent laminate of Comparative Example 1 was prepared in the same manner as in Example 1, except that a hard coat agent with the mixing ratio shown in Table 6 was used.

[0185] [Table 6]

[0186] Comparative Example 2 A transparent laminate of Comparative Example 2 was prepared in the same manner as in Example 1, except that a hard coat agent with the mixing ratio shown in Table 7 was used.

[0187] [Table 7]

[0188] Reference example 1 The above UTG was used as reference example 1 for evaluation.

[0189] The components used in Tables 1-7 are described in detail below. 200PA-E5: Product name "Epoxy Ester 200PA-E5", manufactured by Kyoeisha Chemical Co., Ltd. (A compound having one or more cationic polymerizable functional groups and one or more radical polymerizable functional groups in one molecule) Epolite 1600N: Product name "Epolite 1600N", manufactured by Kyoeisha Chemical Co., Ltd. (Aliphatic compound having two or more cationic polymerizable groups in the molecule), contains 1,6-hexanediol diglycidyl ether, functional group equivalent: 140-160, short chain length compound B Epolite 400E: Product name "Epolite 400E", manufactured by Kyoeisha Chemical Co., Ltd. (Aliphatic compound having two or more cationic polymerizable groups in the molecule), contains nonaethylene glycol diglycidyl ether, functional group equivalent: 264-290, long chain compound B Omnirad127: Product name "Omnirad127", manufactured by IGM Resins BV (radical polymerization initiator) Triarylsulfonium and tetrapentafluorophenylgallium salts: Cationic polymerization initiators ADEKA Stab AO-02: Product name "ADEKA Stab AO-02", manufactured by ADEKA Corporation (antioxidant) RS-57: Product name "RS-57", a radical-curable polyorganosiloxane that does not contain compounds classified as PFAS, manufactured by DIC Corporation (leveling agent). MIBK: Methyl isobutyl ketone (solvent) MEK: Methyl ethyl ketone (solvent)

[0190] [evaluation] The following evaluations were performed on the transparent laminates prepared in the examples and comparative examples, as well as the glass substrates in the reference example, and the results are shown in Table 8.

[0191] (1) Microhardness measurement The hard coat layer surface of the transparent laminates prepared in the examples and comparative examples was prepared using a nanoindenter (product name "ENT-2100", manufactured by Elionix Co., Ltd.) to create a Berkovich indenter. Ten points were measured under a maximum load of 500 μN, and the average values ​​of the indentation modulus and indentation hardness were determined. The ratio of indentation modulus to indentation hardness (indentation modulus / indentation hardness) was calculated from the average values ​​of the indentation modulus and indentation hardness.

[0192] (2) Pencil hardness The pencil hardness of the hard coat layer surface of the transparent laminates prepared in the examples and comparative examples was evaluated according to JIS K5600-5-4 (750g load).

[0193] (3) Flexibility The transparent laminates prepared in the examples and comparative examples, and the glass substrates in the reference example, were measured using a cylindrical mandrel bending tester (product name "Bending Tester (Cylindrical Mandrel Method)", manufactured by TP Giken Co., Ltd.) with the hard coat layer facing inward, using the cylindrical mandrel method in accordance with JIS K5600-5-1 (1999).

[0194] [Table 8]

[0195] The transparent laminates in the examples had a pencil hardness of H or higher, a minimum bending radius of 1.5 mm or less when a cylindrical mandrel test was performed with the hard coat layer side concave, and a ratio of indentation modulus to indentation hardness in microhardness measurement of 6.0 or higher. Thus, it was possible to produce transparent laminates with excellent flexibility while maintaining high hardness. On the other hand, when the ratio of indentation modulus to indentation hardness in microhardness measurement was less than 6.0, it was confirmed that the flexibility was poor (Comparative Example 1) or the surface hardness was insufficient (Comparative Example 2).

[0196] Variations of the invention described herein are listed below. [Note 1] A transparent laminate having a substrate and a hard coat layer laminated on at least one surface of the substrate, The pencil hardness of the hard coat layer surface under a 750g load is H or higher. When a cylindrical mandrel test is performed with the surface of the hard coat layer of the transparent laminate concave, the minimum bending radius is 1.5 mm or less. A transparent laminate in which the ratio of indentation modulus to indentation hardness (indentation modulus / indentation hardness) in a microhardness test of the transparent laminate is 6.0 or higher. [Note 2] The transparent laminate according to Appendix 1, wherein the haze of the hard coat layer is 1.0% or less. [Note 3] The hard coat layer is a cured product of a curable composition containing one or more curable compounds. The transparent laminate according to Appendix 1 or 2, comprising an aliphatic compound having two or more cationic polymerizable groups in its molecule as the curable compound. [Note 4] The transparent laminate according to Appendix 3, comprising polyorganosilsesquioxane as the curable compound. [Note 5] The transparent laminate according to Appendix 3 or 4, comprising two or more of the aliphatic compounds as the curable compound. [Note 6] The transparent laminate according to any one of appendices 3 to 5, wherein the curable composition further comprises a curing catalyst. [Note 7] The transparent laminate according to Appendix 6, comprising the curing catalyst as a cationic polymerization initiator. [Note 8] The transparent laminate according to Appendix 6 or 7, comprising the curing catalyst as a radical polymerization initiator. [Note 9] The transparent laminate according to any one of the appendices 1 to 8, wherein the hard coat layer does not contain a compound corresponding to PFAS. [Note 10] A transparent laminate according to any one of the appendices 1 to 9, having a surface protective film on at least one surface. [Note 11] A transparent laminate according to any one of appendices 1 to 10, having the hard coat layer on one side of the substrate and an adhesive layer on the other side. [Note 12] The transparent laminate according to any one of the appendices 1 to 11, wherein the substrate is glass with a thickness of 30 to 100 μm. [Note 13] An image display device comprising a transparent laminate as described in any one of the appendices 1 to 12. [Note 14] A flexible display, as described in Appendix 13. [Note 15] An image display device as described in Appendix 13 or 14, which is an organic electroluminescent display device. [Note 16] A flexible device including an image display device as described in any one of the appendices 13 to 15.

Claims

1. A transparent laminate having a substrate and a hard coat layer laminated on at least one surface of the substrate, The pencil hardness of the surface of the hard coat layer under a 750g load is H or higher. When a cylindrical mandrel test is performed with the surface of the hard coat layer of the transparent laminate concave, the minimum bending radius is 1.5 mm or less. The ratio of indentation modulus to indentation hardness (indentation modulus / indentation hardness) in the microhardness test of the transparent laminate is 6.0 or higher. The indentation modulus is 400 MPa or more, and the indentation hardness is 50 MPa or more. The hard coat layer is a cured product of a curable composition containing a curable compound. A transparent laminate comprising, as the curable compound, a polyorganosylsesquioxane, an aliphatic compound having a functional group equivalent of 50 to 200 and two or more cationic polymerizable groups in the molecule, and an aliphatic compound having a functional group equivalent of more than 200 to 500 and two or more cationic polymerizable groups in the molecule.

2. The transparent laminate according to claim 1, wherein the haze of the hard coat layer is 1.0% or less.

3. The transparent laminate according to claim 1 or 2, wherein the curable composition further comprises a curing catalyst.

4. The transparent laminate according to claim 3, wherein the curing catalyst comprises a cationic polymerization initiator.

5. The transparent laminate according to claim 3, wherein the curing catalyst comprises a radical polymerization initiator.

6. The permeable coating according to claim 1 or 2, wherein the hard coat layer does not contain a compound corresponding to PFAS. Bright laminate.

7. A transparent laminate according to claim 1 or 2, having a surface protective film on at least one surface.

8. The transparent laminate according to claim 1 or 2, wherein the substrate has the hard coat layer on one side and the adhesive layer on the other side.

9. The transparent laminate according to claim 1 or 2, wherein the substrate is glass with a thickness of 30 to 100 μm.

10. An image display device comprising a transparent laminate according to claim 1 or 2.

11. The image display device according to claim 10, which is a flexible display.

12. The image display device according to claim 10, which is an organic electroluminescent display device.

13. A flexible device including the image display device described in claim 10.

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