Transparent laminate, image display device, and flexible device

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] The present disclosure relates to a transparent laminate, an image display device, and a flexible device. [Background technology]

[0002] In order to improve the portability of mobile information terminals such as smartphones and tablets, there is an increasing demand for foldable devices such as foldable displays and touch panels. A configuration in which a hard coat layer is used as a cover material on the outermost surface of the display of such foldable devices is known. Furthermore, the hard coat layer is required to have high hardness to prevent scratches and indentations while exhibiting transparency and aesthetic appearance. Patent Document 1, for example, is an example of an invention that uses such a high-hardness hard coat layer. [Prior art documents] [Non-patent literature]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-081716 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the hard coat layer of Patent Document 1 has a problem in that when the hardness is increased, the flexibility (bending property) decreases, and cracks tend to occur in the hard coat layer or the substrate.

[0005] The present disclosure is intended to solve the above-mentioned problems, and an object of the present disclosure is to provide a transparent laminate that has high hardness and excellent flexibility. [Means for solving the problem]

[0006] The inventors of the present disclosure have found that a transparent laminate having a substrate and a hard coat layer laminated on at least one surface of the substrate can have high hardness and excellent flexibility if the surface of the hard coat layer satisfies specific ranges for pencil hardness, minimum bendable radius, and ratio of indentation modulus to indentation hardness in microhardness measurement. The present disclosure has been completed based on these findings.

[0007] That is, the transparent laminate is a transparent laminate having a substrate and a hard coat layer laminated on at least one surface of the substrate, and is characterized in that the pencil hardness at the surface of the hard coat layer under a 750 g load is H or more, the minimum bending radius when a cylindrical mandrel test is performed with the surface of the hard coat layer of the transparent laminate made concave is 1.5 mm or less, and the ratio of the indentation modulus to the indentation hardness (indentation modulus / indentation hardness) in a microhardness test of the transparent laminate is 6.0 or more.

[0008] When the pencil hardness is H or higher, the minimum bendable radius is 1.5 mm or less, and the ratio of the indentation modulus to the indentation hardness is 6.0 or higher, the hard coat surface has high hardness yet excellent flexibility.

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

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

[0011] The curable compound preferably contains polyorganosilsesquioxane.

[0012] The curable compound preferably contains two or more of the above aliphatic compounds. By having the above structure, it becomes easy to achieve both high hardness and flexibility.

[0013] The curable composition preferably further contains a curing catalyst.

[0014] The curing catalyst preferably contains a cationic polymerization initiator.

[0015] The curing catalyst preferably contains a radical polymerization initiator.

[0016] In addition, it is preferable that the hard coat layer of the transparent laminate does not contain any compounds that fall under PFAS.

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

[0018] The transparent laminate preferably has the hard coat layer on one surface of the substrate and an adhesive layer on the other surface.

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

[0020] The present disclosure also provides an image display device including the transparent laminate.

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

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

[0023] The present disclosure also provides a flexible device including the image display device. [Effects of the Invention]

[0024] The transparent laminate of the present disclosure has high hardness and excellent flexibility, and can therefore be suitably used in image display devices such as flexible displays. DETAILED DESCRIPTION OF THE INVENTION

[0025] In this disclosure, "compounds that fall under PFAS" is a general term for perfluoroalkyl compounds and polyfluoroalkyl compounds.

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

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

[0028] The transparent laminate has a pencil hardness of H or more, preferably 2H or more, of the hard coat layer surface measured in accordance with JIS K5600-5-4. A pencil hardness of H or more ensures sufficient surface hardness and facilitates the exertion of abrasion resistance. When hard coat layers are laminated on both sides of the transparent laminate, it is sufficient that the hard coat layer satisfies the above range on at least one side.

[0029] In a cylindrical mandrel test conducted in accordance with JIS K5600-5-1, in which the transparent laminate is bent so that the surface of the hard coat layer is concave, the minimum bending diameter at which cracks do not occur is 1.5 mm or less. Having a minimum bending diameter of 1.5 mm or less allows the transparent laminate to exhibit sufficient flexibility. When hard coat layers are laminated on both sides of the transparent laminate, it is sufficient that at least one side satisfies the above range, and it is preferable that the hard coat layer having a pencil hardness of H or higher satisfies the above minimum bending diameter.

[0030] The transparent laminate preferably has an indentation modulus of 400 to 4000 MPa, more preferably 600 to 3500 MPa, and even more preferably 800 to 3000 MPa, in a microhardness measurement of the surface of the hard coat layer. When the indentation modulus is 400 MPa or more, the surface hardness tends to be excellent. When the indentation modulus is 4000 MPa or less, it is possible to achieve both elongation and flexibility while maintaining rigidity.

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

[0032] The transparent laminate has a ratio of the indentation modulus to the indentation hardness (indentation modulus / indentation hardness) of 6.0 or more, preferably 6.5 or more, and more preferably 7.0 or more. Having a ratio of 6.0 or more allows for sufficient surface hardness while providing excellent flexibility. While the upper limit is not particularly limited, it is preferably 80.0 or less to ensure sufficient surface hardness.

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

[0034] <Base material> The substrate in the transparent laminate of the present disclosure may be a known or commonly used substrate such as a plastic substrate, a metal substrate, a ceramic substrate, a semiconductor substrate, a glass substrate, a paper substrate, a wood substrate (wooden substrate), or a substrate with a painted surface. Among these, from the viewpoint of exhibiting transparency, a glass substrate or a plastic substrate is preferred, and a glass substrate is particularly preferred. Furthermore, the substrate may have a single-layer structure or a multilayer structure, and may be composed of one type of material or two or more types of materials.

[0035] The glass substrate may be chemically strengthened to improve its strength against cracking when the glass is thinned and to provide a panel that can withstand practical use, and is preferably edge-treated to provide a substrate with sufficient strength. Furthermore, a treatment layer or coating film may be formed on either surface to improve abrasion resistance, smoothness, and strength against cracking.

[0036] The thickness of the substrate is, for example, preferably 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, the substrate can easily exhibit sufficient strength. When the thickness of the glass substrate is 100 μm or less, the substrate can easily exhibit flexibility.

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

[0038] The surface protection film may be any known or conventional surface protection film, and is not particularly limited thereto. For example, a plastic film having a pressure-sensitive adhesive layer on its surface may be used. Examples of the plastic film include plastic films made of 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 pressure-sensitive adhesive layer include pressure-sensitive adhesive layers made of one or more known or conventional pressure-sensitive adhesives such as acrylic pressure-sensitive adhesives, silicone pressure-sensitive adhesives, natural rubber pressure-sensitive adhesives, synthetic rubber pressure-sensitive adhesives, ethylene-vinyl acetate copolymer pressure-sensitive adhesives, ethylene-(meth)acrylate copolymer pressure-sensitive adhesives, styrene-isoprene block copolymer pressure-sensitive adhesives, and styrene-butadiene block copolymer pressure-sensitive adhesives. The pressure-sensitive adhesive layer may contain various additives (e.g., antistatic agents, slip agents, etc.). The plastic film and the pressure-sensitive adhesive layer may each have a single-layer structure or a multi-layer (multi-layer) structure. The thickness of the surface protection film is not particularly limited and can be selected appropriately.

[0039] Examples of the surface protection film include commercially available products such as the "SaniTect" series (manufactured by San-A Chemical Co., Ltd.), the "E-MASK" series (manufactured by Nitto Denko Corporation), the "Mastack" series (manufactured by Fujimori Kogyo Co., Ltd.), the "Hitalex" series (manufactured by Hitachi Chemical Co., Ltd.), and the "Alphan" series (manufactured by Oji F-Tex Co., Ltd.).

[0040] The transparent laminate may also have an adhesive layer. The adhesive layer is preferably laminated on the surface of the substrate opposite to the surface on which the hard coat layer is laminated in the transparent laminate. That is, when the transparent laminate has the adhesive layer, it is preferable that the hard coat layer is on one surface of the substrate and the adhesive layer is on the other surface. It is more preferable that the transparent laminate has the adhesive layer on one surface.

[0041] The adhesive constituting the adhesive layer can be the same adhesive as the adhesive exemplified for the surface protection film. Among them, acrylic adhesives and silicone adhesives are preferred, and acrylic adhesives are particularly preferred, because they have good transparency and can provide sufficient adhesive strength even when thin. The adhesives can be used alone or in combination of two or more.

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

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

[0045] The material of the undercoat layer is not particularly limited, and examples thereof include resins. Examples of resins include (meth)acrylic resins, urethane resins, (meth)acrylic urethane copolymers, vinyl chloride-vinyl acetate copolymers, polyesters, butyral resins, chlorinated polypropylene, chlorinated polyethylene, epoxy resins, and silicone resins. These resins may be used alone or in combination of two or more.

[0046] The thickness of the undercoat layer is preferably 0.1 to 30 μm, more preferably 1 to 20 μm. When the thickness of the undercoat layer is within this range, adhesion between the undercoat layer and the substrate is exhibited, and when a hard coat layer is further laminated thereon, the surface hardness of the hard coat layer can be easily improved.

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

[0048] The undercoat layer can be formed by a conventional coating method. 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, and organic vapor deposition can be used. Examples of curing treatment include light irradiation using a mercury lamp, xenon lamp, carbon arc lamp, metal halide lamp, sunlight, electron beam source, laser light source, LED light source, etc. The cumulative irradiation dose is, for example, 300 to 10,000 mJ / cm. 2 Alternatively, a film that has been coated in advance on another substrate by the above-described formation method may be transferred onto the substrate by a transfer method such as adhesive transfer, thermal transfer, or UV transfer.

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

[0050] <Hard coat layer> In the transparent laminate, the hard coat layer may be formed on only one side (single surface) of the substrate, or may be formed on both sides (both surfaces) of the substrate. However, when the transparent laminate has the adhesive layer, it is preferable that it is formed on only one surface of the substrate. When hard coat layers are formed on both sides of the substrate, it is sufficient that at least one surface satisfies the physical properties of the hard coat layer described above and below. The hard coat layers may be the same or may be layers of different thicknesses or compositions. Furthermore, a hard coat layer may be formed on one surface of the substrate, and the other layer may be formed on the other surface. From the viewpoint of suppressing cracking, it is preferable that the hard coat layer is formed on at least one surface of the substrate, and the hard coat layer or the other layer is formed on the other surface.

[0051] The hard coat layer 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. Only one type of the curable compound may be used, or two or more types may be used.

[0052] The curable compound preferably contains polyorganosilsesquioxane. By containing the polyorganosilsesquioxane, the curable composition is less likely to shrink during curing, thereby making it possible to form a hard coat layer with high hardness and excellent scratch resistance. Examples of the polyorganosilsesquioxane include radical polymerizable polyorganosilsesquioxane and cationically polymerizable polyorganosilsesquioxane. Among these, cationically polymerizable polyorganosilsesquioxane is preferred, and the cationically polymerizable polyorganosilsesquioxane is more preferably a photocationically polymerizable polyorganosilsesquioxane.

[0053] The radically polymerizable polyorganosilsesquioxane has a radically polymerizable functional group in the molecule, such as a (meth)acryloyl group, a (meth)acrylamide group, a vinyl group, or a vinylthio group.

[0054] The cationically polymerizable polyorganosilsesquioxane has a cationically polymerizable functional group in the molecule. Examples of the cationically polymerizable functional group include an epoxy group, an oxetane group, a vinyl ether group, and a vinylphenyl group. Among these, an epoxy group is preferred from the viewpoint of increasing the surface hardness of the hard coat layer.

[0055] The epoxy group-containing group includes, but is not limited to, known or commonly used groups having an oxirane ring. From the viewpoint of the curability of the curable composition and the heat resistance of the hard coat layer, preferred are groups represented by the following formula (1a), (1b), (1c), and (1d), more preferred are groups represented by the following formula (1a) and (1c), and even more preferred are groups represented by the following 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 methylene, methylmethylene, dimethylmethylene, ethylene, propylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, and decamethylene. Among these, R 1a From the viewpoint of the curability of the curable composition, the alkylene group is preferably a linear alkylene group having 1 to 4 carbon atoms or a branched alkylene group having 3 or 4 carbon atoms, more preferably an ethylene group, a trimethylene group, or 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 R 1a Among them, R 1b From the viewpoint of the curability of the curable composition, the alkylene group is preferably a linear alkylene group having 1 to 4 carbon atoms or a branched alkylene group having 3 or 4 carbon atoms, more preferably an ethylene group, a trimethylene group, or 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 R 1a Among them, R 1c From the viewpoint of the curability of the curable composition, the alkylene group is preferably a linear alkylene group having 1 to 4 carbon atoms or a branched alkylene group having 3 or 4 carbon atoms, more preferably an ethylene group, a trimethylene group, or 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 R 1a Among them, R 1dFrom the viewpoint of the curability of the curable composition, the alkylene group is preferably a linear alkylene group having 1 to 4 carbon atoms or a branched alkylene group having 3 or 4 carbon atoms, more preferably an ethylene group, a trimethylene group, or a propylene group, and even more preferably an ethylene group or a trimethylene group.

[0060] R in formula (1) 1 As the group represented by the formula (1a), R 1a is an ethylene group [particularly, a 2-(3,4-epoxycyclohexyl)ethyl group] is preferred.

[0061] The polyorganosilsesquioxane may, for example, be a compound having a constituent unit represented by the following formula (1). [R 1 SiO 3 / 2 ] (1)

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

[0063] The silsesquioxane (X) may have only one type of constitutional unit represented by the above formula (1), or may have two or more types of constitutional units represented by the above formula (1).

[0064] Silsesquioxane (X) is a silsesquioxane building block [RSiO 3 / 2 In addition to the constitutional unit represented by the above formula (1), the following constitutional unit represented by the following formula (2) may also be included. [R 2SiO 3 / 2 ] (2)

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

[0066] R in the above formula (2) 2 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 a phenyl group, a tolyl group, and a naphthyl group. Examples of the aralkyl group include a benzyl group and a phenethyl group. Examples of the cycloalkyl group include a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group. Examples of the alkyl group include a straight-chain or branched-chain alkyl group such as a methyl group, an ethyl group, a propyl group, an n-butyl group, an isopropyl group, an isobutyl group, an s-butyl group, a t-butyl group, and an isopentyl group.

[0067] Examples of the above-mentioned substituted aryl group, substituted aralkyl group, substituted cycloalkyl group, and substituted alkyl group include groups in which the hydrogen atoms or part or all of the main chain skeleton of the above-mentioned aryl group, aralkyl group, cycloalkyl group, and alkyl group are substituted with at least one selected from the group consisting of alkyl groups (particularly, 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 hydroxy groups (hydroxyl groups).

[0068] Among them, R 2 As the alkyl group, a substituted or unsubstituted aryl group or a substituted or unsubstituted alkyl group is preferable, a substituted or unsubstituted aryl group is more preferable, and a phenyl group is even more preferable.

[0069] The proportion of each of the above-mentioned silsesquioxane structural units (structural unit represented by formula (1) and structural unit represented by formula (2)) in the silsesquioxane (X) can be appropriately adjusted by changing the composition of the raw material (hydrolyzable trifunctional silane) for forming these structural units.

[0070] Silsesquioxane (X) is, among others, R 1 a structural unit represented by the above formula (1) in which R is a group containing an alicyclic epoxy group, and 2 is an optionally substituted aryl group. In this case, the hard coat layer tends to have better surface hardness, flexibility, processability, and flame retardancy.

[0071] Silsesquioxane (X) contains, in addition to the constitutional units represented by the above formula (1) and the constitutional units represented by the above formula (2), a T unit, further containing [RSiO 1 / 2 ] (so-called M unit), [R2SiO 2 / 2 ] (so-called D unit), and [SiO 4 / 2 In addition, R in the M unit and the D unit may be selected from the group consisting of R in the structural unit represented by the formula (1). 1 and the structural unit R represented by the above formula (2) 2 Examples of silsesquioxane structural units other than the structural unit represented by the above formula (1) and the structural unit represented by the above formula (2) include structural units represented by the following formula (3): [HSiO 3 / 2 ] (3)

[0072] The silsesquioxane (X) contains a structural unit (T3 form) represented by the following formula (I), and may further contain a structural unit (T2 form) represented by the following formula (II). [R a SiO 3 / 2 ] (I) [R b SiO2 / 2 (OR c )] (II)

[0073] The structural unit represented by formula (I) above can be described in more detail as represented by formula (I') below. Furthermore, the structural unit represented by formula (II) above can be described in more detail as represented by formula (II') below. Each of the three oxygen atoms bonded to the silicon atom in the structure represented by formula (I') below is bonded to another silicon atom (a silicon atom not shown in formula (I')). Meanwhile, each of the two oxygen atoms located above and below the silicon atom in the structure represented by formula (II') below is bonded to another silicon atom (a silicon atom not shown in formula (II')). That is, the T3 and T2 forms are both structural units (T units) formed by the hydrolysis and condensation reaction of the corresponding hydrolyzable trifunctional silane compounds. [ka] [ka]

[0074] R in the above formula (I) a (R in formula (I') a The same applies to R in formula (II). b (R in formula (II') b and (the same applies to R and R) respectively represent a group containing a cationically 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 Specific examples of R in the above formula (1) include 1 , R in the above formula (2) 2 Examples of the R a and R in formula (II) bare each a group derived from a group (a group other than an alkoxy group or a halogen atom) bonded to a silicon atom in the hydrolyzable trifunctional silane compound used as a raw material for the silsesquioxane (X), or, for example, when the cationically polymerizable functional group is an epoxy group, a group obtained by epoxidizing a group (a group other than an alkoxy group or a halogen atom) bonded to a silicon atom in the hydrolyzable trifunctional silane compound used as a raw material for the silsesquioxane (X).

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

[0076] The molar ratio of the structural unit represented by formula (I) (T3 isomer) to the structural unit represented by formula (II) (T2 isomer) in the silsesquioxane (X) [structural unit represented by formula (I) / structural unit represented by formula (II)] (sometimes referred to as "T3 isomer / T2 isomer") 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 molar ratio [T3 isomer / T2 isomer] to 5 or more, the surface hardness of the hard coat layer tends to be further improved.

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

[0078] Silsesquioxane (X) 29 The Si-NMR spectrum can be measured, for example, using the following apparatus and conditions. Measurement equipment: Product name "JNM-ECA500NMR" (manufactured by JEOL Ltd.) Solvent: deuterated chloroform Accumulation count: 1800 times Measurement temperature: 25℃

[0079] The molar ratio [T3 / T2] of silsesquioxane (X) being 5 or more means that a certain amount of T2 isomers is present relative to the T3 isomers in silsesquioxane (X). Examples of such T2 isomers include a structural unit represented by the following formula (4), a structural unit represented by the following formula (5), and a structural unit represented by the following formula (6). R in the following formula (4) 1 and R in the following formula (5) 2 are R in the above formula (1), respectively. 1 and R in the above formula (2) 2 The same as R in the following formulas (4) to (6): c is R in formula (II)c As with the above, 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 (particularly, the silsesquioxane (X)) may be a silsesquioxane having a cage shape (cage silsesquioxane). The cage silsesquioxane includes a complete cage silsesquioxane and an incomplete cage silsesquioxane, and among these, an incomplete cage silsesquioxane is preferred.

[0081] Generally, a complete cage silsesquioxane is a polyorganosilsesquioxane composed only of T3 isomers, and no T2 isomers are present in the molecule. That is, the molar ratio [T3 isomer / T2 isomer] is 5 or more, and as described later, the peak at 1100 cm in the FT-IR spectrum is -1 When a silsesquioxane has one characteristic absorption peak in the vicinity, it is suggested that the silsesquioxane has an incomplete cage silsesquioxane structure.

[0082] Whether or not silsesquioxane (X) has a cage (incomplete cage) silsesquioxane structure can be confirmed by FT-IR spectroscopy [Reference: R.H. Raney, M. Itoh, A. Sakakibara and T. Suzuki, Chem. Rev. 95, 1409 (1995)]. Specifically, in the FT-IR spectrum, -1 Near and 1150cm -1 There is no specific absorption peak near 1100 cm -1In contrast, when there is a specific absorption peak in the vicinity of 1050 cm in the FT-IR spectrum, the silsesquioxane (X) can be identified as having a cage (incomplete cage) silsesquioxane structure. -1 Near and 1150cm -1 When the silsesquioxane (X) has a characteristic absorption peak in the vicinity of the FT-IR spectrum, it is identified as having a ladder-type silsesquioxane structure. The FT-IR spectrum of the 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 Accumulation count: 16 times

[0083] The proportion (total amount) of structural units having a cationically polymerizable functional group (e.g., structural units represented by the above formula (1) and structural units represented by the above formula (4)) relative to the total amount of siloxane structural units in the polyorganosilsesquioxane (total siloxane structural units; the total amount of M units, D units, T units, and Q units) (100 mol%) 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 proportion 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 proportion of each siloxane structural unit in the polyorganosilsesquioxane can be calculated, for example, from the composition of the raw materials or NMR spectroscopy.

[0084] The proportion of the structural units represented by formula (I) (T3 isomer) relative to the total amount of siloxane structural units in silsesquioxane (X) [total siloxane structural units; total amount of M units, D units, T units, and Q units] (100 mol%) 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%. By making the proportion of T3 structural units 50 mol% or more, it is presumed that this is because it becomes easier to form an incomplete cage structure with an appropriate molecular weight, and the surface hardness of the hard coat layer tends to be further improved.

[0085] The proportion (total amount) of the structural units represented by the above formula (2) and the structural units represented by the above formula (5) relative to the total amount of siloxane structural units in the silsesquioxane (X) [total siloxane structural units; total amount of 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 proportion at 50 mol% or less, the proportion of structural units having cationically polymerizable functional groups can be relatively increased, which improves the curability of the curable composition and tends to further increase the surface hardness of the hard coat layer.

[0086] The proportion (total amount) of the structural units represented by the above formula (I) and the structural units represented by the above formula (II) (particularly, the total proportion of the T3 and T2 isomers) relative to the total amount of siloxane structural units in the silsesquioxane (X) [total siloxane structural units; the total amount of M units, D units, T units, and Q units] (100 mol%) is not particularly limited, but is preferably 60 mol% or more (e.g., 60 to 100 mol%), more preferably 70 mol% or more, even more preferably 80 mol% or more, and particularly preferably 90 mol% or more. By setting the proportion at 60 mol% or more, it is presumed that this facilitates the formation of an incomplete cage structure having an appropriate molecular weight, which tends to further improve the surface hardness of the hard coat layer. In particular, it is preferable that the proportions (total amount) of the structural units represented by the above formula (1), the structural units represented by the above formula (2), the structural units represented by the above formula (4), and the structural units represented by the above formula (5) are within the above ranges.

[0087] The number average molecular weight (Mn) of the silsesquioxane (X) in terms of standard polystyrene determined by gel permeation chromatography is not particularly limited, but is preferably 1000 to 3000, more preferably 1000 to 2800, even more preferably 1100 to 2600, and particularly preferably 1500 to 2500. By setting the number average molecular weight to 1000 or more, the surface hardness of the hard coat layer tends to be further improved. The heat resistance and abrasion resistance of the hard coat layer tend to be improved. On the other hand, by setting the number average molecular weight to 3000 or less, the compatibility with other components in the curable composition is improved, and the heat resistance of the hard coat layer tends to be improved.

[0088] The molecular weight dispersity (Mw / Mn) of the silsesquioxane (X) in terms of standard polystyrene as determined by gel permeation chromatography 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 particularly preferably 1.45 to 1.80. By setting the molecular weight dispersity to 3.0 or less, the surface hardness of the hard coat layer tends to be higher. On the other hand, by setting the molecular weight dispersity to 1.0 or more (particularly 1.1 or more), the silsesquioxane tends to be easily liquid, and handleability tends to be improved.

[0089] The number average molecular weight and molecular weight dispersity of the silsesquioxane (X) can be measured using the following apparatus and conditions. Measuring device: Product name "LC-20AD" (Shimadzu Corporation) Columns: Shodex KF-801 x 2, KF-802, and KF-803 (Showa Denko K.K.) 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: Standard polystyrene equivalent

[0090] Polyorganosilsesquioxanes can be produced by known or conventional methods for producing silsesquioxanes, and are not particularly limited thereto. For example, they can be produced by a method in which one or more hydrolyzable silane compounds are hydrolyzed and condensed.

[0091] The content of polyorganosilsesquioxane in the curable composition is not particularly limited, but is preferably greater than 50% by mass (e.g., greater than 50% by mass but not greater than 98% by mass) relative to the total amount (100% by mass) of the curable compounds, 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 content is greater than 50% by mass, the surface hardness of the hard coat layer tends to be further improved. When the content is 98% by mass or less, other components can be contained, and the effects obtained by containing these components tend to be further improved. In addition, a curing catalyst can be contained, which tends to more efficiently promote curing of the curable composition.

[0092] The curable composition may contain a compound having one or more cationically polymerizable groups and one or more radically polymerizable groups in the molecule (hereinafter, sometimes referred to as "compound A"). When the curable composition contains compound A, the crosslink density of the cured product can be effectively increased, and the hard coat layer can be easily imparted with high surface hardness and excellent flexibility and flexural durability, while the antifouling performance can be made less susceptible to deterioration. Only one type of compound A may be used, or two or more types may be used.

[0093] Examples of the "cationically polymerizable group" possessed by Compound A include an epoxy group, an oxetanyl group, a vinyl ether group, etc., and from the viewpoint of suppressing a decrease in the surface hardness, flexibility, and flexural durability of the hard coat layer, an epoxy group is preferred. When Compound A has two or more cationically polymerizable groups, these cationically polymerizable groups may be the same or different.

[0094] Examples of the "radical polymerizable group" possessed by Compound A include a (meth)acryloyl group and a vinyl group, and from the viewpoint of the surface hardness and flexural durability of the hard coat layer, a (meth)acryloyl group is preferred. When Compound A has two or more radical polymerizable groups, these radical polymerizable groups may be the same or different.

[0095] The number of cationically polymerizable groups that compound A has in one molecule may be 1 or more and is not particularly limited, but is preferably 1 to 5, more preferably 1 to 3, and even more preferably 1 or 2. The number of radically polymerizable groups that compound A has in one molecule may be 1 or more and is not particularly limited, but is, for example, preferably 1 to 5, more preferably 1 to 3, and even more preferably 1 or 2.

[0096] The functional group equivalent of the cationically 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 becomes easy to ensure sufficient flexural durability of the hard coat layer. When the functional group equivalent is 500 or less, it becomes possible to ensure sufficient surface hardness of the hard coat layer. The functional group equivalent of the cationically polymerizable group of compound A can be calculated by the following formula. [Functional group equivalent of cationically polymerizable group]=[Molecular weight of compound A] / [Number of cationically 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 becomes easy to ensure sufficient flexural durability of the hard coat layer. When the functional group equivalent is 500 or less, it becomes possible to ensure sufficient surface hardness of the hard coat layer. The functional group equivalent of the radical polymerizable group of compound A can be calculated by the following formula. [Functional group equivalent of radical polymerizable group]=[Molecular weight of compound A] / [Number of radical polymerizable groups in compound A]

[0098] Specific examples of compound A include 3,4-epoxycyclohexylmethyl(meth)acrylate, glycidyl(meth)acrylate, tripropylene glycol diglycidyl ether di(meth)acrylate (a compound obtained by reacting both epoxy groups of tripropylene glycol diglycidyl ether with (meth)acrylic acid), tripropylene glycol diglycidyl ether half(meth)acrylate (a compound obtained by reacting one epoxy group of tripropylene glycol diglycidyl ether with (meth)acrylic acid), bisphenol A epoxy di(meth)acrylate (a compound obtained by reacting both epoxy groups of bisphenol A diglycidyl ether with (meth)acrylic acid), bisphenol A epoxy half(meth)acrylate (a compound obtained by reacting one epoxy group of bisphenol A diglycidyl ether with (meth)acrylic acid or a derivative thereof), bisphenol F epoxy di(meth)acrylate, bisphenol F epoxy half(meth)acrylate, bisphenol S epoxy di(meth)acrylate, bisphenol S epoxy half(meth)acrylate, Compounds having an epoxy 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, and other compounds having an oxetanyl group and a (meth)acryloyl group in one molecule; 2-vinyloxyethyl (meth)acrylate, 3-vinyloxyethyl (meth)acrylate, oxypropyl, 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,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)acrylate, (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, 2-(vinyloxyisopropoxyethoxy)ethyl (meth)acrylate, (meth)acrylate (meth)acrylate 2-(vinyloxyisopropoxyisopropoxy)ethyl, (meth)acrylate 2-(vinyloxyethoxyethoxy)propyl, (meth)acrylate 2-(vinyloxyethoxyisopropoxy)propyl, (meth)acrylate 2-(vinyloxyisopropoxyethoxy)propyl, (meth)acrylate 2-(vinyloxyisopropoxyisopropoxy)propyl, (meth)acrylate 2-(vinyloxyethoxyethoxy)isopropyl, (meth)acrylate 2-(vinyloxyethoxyisopropoxy)isopropyl, (meth)acrylate 2-(vinyloxyethoxyisopropoxy)isopropyl, (meth)acrylate 2-(vinyloxyethoxyisopropoxy)isopropyl ) 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-(isopropenoxyethoxyethoxy)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 cationically polymerizable group and a (meth)acryloyl group as a radically polymerizable group in one molecule, and 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 a portion of the cationically polymerizable groups of a compound having two or more cationically polymerizable groups (e.g., epoxy groups) in one molecule with a carboxylic acid having a radically polymerizable group (e.g., acrylic acid, methacrylic acid, etc.) or a derivative thereof. Furthermore, as the compound A, commercially available products such as those under the trade names "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 Co., Ltd.) can also be used.

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

[0102] The content (blending amount) of compound A in the curable composition is not particularly limited, but 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, based on 100 parts by mass of the polyorganosilsesquioxane, as a solid content. By setting the content of compound A to 1 part by mass or more, the flexibility and flexural durability of the hard coat layer tend to be further improved. On the other hand, by setting the content of compound A to 100 parts by mass or less, the surface hardness of the hard coat layer tends to be maintained.

[0103] The curable composition preferably contains an aliphatic compound having two or more cationically polymerizable groups in the molecule (hereinafter, sometimes referred to as compound B), and more preferably contains two or more types of compound B. By containing compound B, flexibility of the hard coat layer can be imparted, and it becomes easier to exhibit flexural and flexural durability. In particular, by containing 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 category of polyorganosilsesquioxane or compound A.

[0104] Examples of the cationically polymerizable group include the same groups as those exemplified for compound A. Examples include epoxy groups, oxetanyl groups, vinyl ether groups, etc., and from the viewpoint of exhibiting the surface hardness, flexibility, and flexural durability of the hard coat layer, epoxy groups are preferred, and from the viewpoint of reactivity, glycidyl groups are more preferred. The two or more cationically polymerizable groups possessed by compound B may be the same or different.

[0105] The number of cationically polymerizable groups that compound B has in one molecule is not particularly limited as long as it is two or more, but for example, it is preferably 2 to 5, more preferably 2 to 3, and even more preferably 2.

[0106] The "aliphatic compound" in Compound B refers to an aliphatic compound that does not have a cyclic structure other than the cationic polymerizable group. Examples of Compound B include glycidyl ethers of alcohols that do not have a divalent or higher cyclic structure; and glycidyl esters of divalent or higher carboxylic acids (e.g., adipic acid, sebacic acid, maleic acid, itaconic acid, etc.). Examples of the alcohols that do not have a divalent or higher cyclic structure include dihydric 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 trivalent or higher polyhydric alcohols such as glycerin, diglycerin, erythritol, trimethylolethane, trimethylolpropane, pentaerythritol, dipentaerythritol, and sorbitol. The dihydric or higher alcohol may be a polyether polyol, a polyester polyol, a polycarbonate polyol, a polyolefin polyol, or the like.

[0107] Compound B is preferably a compound having two cationically 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 the linear or branched alkylene group having 2 to 10 carbon atoms include linear or branched alkylene groups having 2 to 10 carbon atoms, such as ethylene, propylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, and decamethylene. Among these, from the viewpoints of improving the surface hardness, flexibility, and flexural durability of the hard coat-less film and preventing a decrease in antifouling performance, M is preferably a linear or branched alkylene group having 3 to 8 carbon atoms, more preferably a linear alkylene group having 5 to 7 carbon atoms, and even more preferably a linear alkylene group having 6 carbon atoms (hexamethylene group). Examples of the ethylene glycol group having 5 to 15 repeating units include a hexaethylene glycol group, a nonaethylene glycol group, and a decaethylene glycol group, and the nonaethylene glycol group is preferred in order to further improve flexibility while maintaining surface hardness. When two or more types of compound B are contained, it is preferred to contain both one in which M is a linear or branched alkylene group having 2 to 10 carbon atoms and one in which M is an ethylene glycol group having 5 to 15 repeating units.

[0109] In the above formula (A), E 1 and E 2 are the same or different and represent a cationically polymerizable functional group, and are preferably a group represented by the following formula (E) from the viewpoints of improving the reactivity, surface hardness, flexibility, and flexural durability of the hard coat layer, and making it difficult for the antifouling performance to decrease. [ka]

[0110] In formula (E), R A represents a linear or branched alkylene group having 1 to 6 carbon atoms. Examples of the linear or branched alkylene group having 1 to 6 carbon atoms include 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, and a decamethylene group. Among these, RA As R, from the viewpoints of improving the reactivity, surface hardness, flexibility, and flexural durability of the hard coat layer, and preventing deterioration of the antifouling performance, a linear alkylene group having 1 to 4 carbon atoms is preferred, more preferably a methylene group or an ethylene group, and even more preferably a methylene group. B represents a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms, preferably a hydrogen atom or a methyl group, more preferably a hydrogen atom.

[0111] The functional group equivalent of the cationically 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 flexural durability of the hard coat layer. When the functional group equivalent is 500 or less, it is possible to ensure sufficient surface hardness of the hard coat layer. Furthermore, when two or more types of compound B are contained, 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 greater than 200 to 500, more preferably 220 to 450, and even more preferably 240 to 400. By using a combination of compounds B having functional group equivalents within the above range, it is possible to maintain surface hardness while exhibiting higher flexibility. The functional group equivalent of the cationically polymerizable group of compound B can be calculated using the following formula: [Functional group equivalent of cationically polymerizable group]=[Molecular weight of compound B] / [Number of cationically polymerizable groups in compound B]

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

[0113] Specific examples of compound B include 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, 2,4-diethyl-1,5-pentanediol Examples of the alkylene glycol diglycidyl ether (alkanediol diglycidyl ether) include 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; and (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. Among these, it is preferable that compound B contains a diol diglycidyl ether and a (poly)alkylene glycol diglycidyl ether, more preferably a diol diglycidyl ether as compound B with a short chain length and a (poly)alkylene glycol diglycidyl ether as compound B with a long chain length, and particularly preferably a combination of nonaethylene glycol diglycidyl ether and 1,6-hexanediol diglycidyl ether.

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

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

[0117] Furthermore, when both short-chain compound B and long-chain compound B are contained, the content of long-chain compound B is preferably 35 to 95 mass %, more preferably 50 to 90 mass %, and even more preferably 65 to 87 mass %, relative to the total amount (100 mass %) of compound B. When the content of long-chain compound B among compounds B is 35 mass % or more, flexibility is easily exhibited. Furthermore, when it is 95 mass % or less, surface hardness can be sufficiently increased.

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

[0119] The curing catalyst is selected depending on the type of curable functional group possessed by the curable compound, and among them, a cationic polymerization initiator and / or a radical polymerization initiator is preferred. The cationic polymerization initiator is a compound that generates cationic species upon exposure to heat or active energy rays, thereby initiating the curing reaction of the curable compound.

[0120] Examples of the cationic polymerization initiator include a photo-cationic polymerization initiator (photo-acid generator) and a thermal cationic polymerization initiator (thermal acid generator).

[0121] As the cationic photopolymerization initiator, known or commonly used cationic photopolymerization initiators can be used, and examples thereof include 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 sulfonium salt include triphenylsulfonium salt, tri-p-tolyl sulfonium salt, tri-o-tolyl sulfonium 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, 4-(p-tolylthio)phenyldi-(p-phenyl)sulfonium salt, triarylsulfonium salts such as diphenylphenacylsulfonium salt, diphenyl 4-nitrophenacylsulfonium salt, diphenylbenzylsulfonium salt, diphenylmethylsulfonium salt, etc.; monoarylsulfonium salts such as phenylmethylbenzylsulfonium salt, 4-hydroxyphenylmethylbenzylsulfonium salt, 4-methoxyphenylmethylbenzylsulfonium salt, etc.; and trialkylsulfonium salts such as dimethylphenacylsulfonium salt, phenacyltetrahydrothiophenium salt, dimethylbenzylsulfonium salt, etc.

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

[0124] Examples of the iodonium salt include trade name "RHODORSIL PHOTOINITIATOR 2074" (manufactured by Rhodia Japan, tetrakis(pentafluorophenyl)borate·[(1-methylethyl)phenyl](methylphenyl)iodonium), trade 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 salt 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 ammonium salt 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-dimethylpyrrolidinium salt and N-ethyl-N-methylpyrrolidinium salt; imidazolinium salts such as N,N'-dimethylimidazolinium salt and N,N'-diethylimidazolinium salt; N,N'-dimethyltetrahydropyrimidium salt and N,N'-diethyltetrahydropyrimidium salt; tetrahydropyrimidium salts such as tetrahydropyrimidium salts; morpholinium salts such as N,N-dimethylmorpholinium salts and N,N-diethylmorpholinium salts; piperidinium salts such as N,N-dimethylpiperidinium salts and N,N-diethylpiperidinium salts; pyridinium salts such as N-methylpyridinium salts and N-ethylpyridinium salts; imidazolium salts such as N,N'-dimethylimidazolium salts; quinolium salts such as N-methylquinolium salts; isoquinolium salts such as N-methylisoquinolium salts; thiazonium salts such as benzylbenzothiazonium salts; and acridium salts such as benzylacridium salts.

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

[0128] Examples of the salts of the transition metal complex ions 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 the like.

[0129] The anion constituting the above salt is, for example, PF6 - , BF4 - , (C6F5)4B - , (C6F5)4Ga - , sulfonate anions (trifluoromethanesulfonate anion, pentafluoroethanesulfonate anion, methanesulfonate anion, benzenesulfonate anion, p-toluenesulfonate 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 thermal cationic polymerization initiator include arylsulfonium salts, aryliodonium salts, allene-ion complexes, quaternary ammonium salts, aluminum chelates, boron trifluoride amine complexes, etc. Examples of the anions constituting the salts include the same anions as those in the photocationic polymerization initiators.

[0131] Examples of the arylsulfonium salt include pentafluorophenyl borate and hexafluorophosphate. In the curable composition of the present disclosure, commercially available products such as those under the trade names "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 aluminum chelate include ethyl acetoacetate aluminum diisopropylate and aluminum tris(ethyl acetoacetate). Examples of the boron trifluoride amine complex include a boron trifluoride monoethylamine complex, a boron trifluoride imidazole complex, and a boron trifluoride piperidine complex.

[0132] The radical polymerization initiator is a compound that generates radicals when exposed to heat or active energy rays, thereby initiating the curing reaction of the curable compound.

[0133] The radical polymerization initiator includes a photoradical polymerization initiator and a thermal radical polymerization initiator, such as an alkylphenone-based photoradical polymerization initiator, an acylphosphine oxide-based photoradical polymerization initiator, an oxime ester-based photoradical polymerization initiator, and an α-hydroxyketone-based photoradical polymerization initiator.

[0134] Examples of the alkylphenone-based photoradical polymerization initiator 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-hydroxy-2-methyl-1-phenylpropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl) ...hydroxy-2-methyl-1-phenylpropan-1-one, 2-benzyl-2-dimethylamino-1-phenylpropan-1-one, 2-benzyl-2-dimethylamino-1-phenylpropan-1-one, 2-benzyl-2-dimethylamino-1-phenylpropan-1-one, 2-benzyl-2-dimethylamino-1-phenylpropan-1-one, 2-benzyl-2-dimethylamino-1-phenylpropan-1-one, 2-benzyl-2-dimethylamino-1-phenylpropan-1-one, 2-benzyl-2-dimethylamino-1-phenylpropan-1-one, ,4-diethylthioxanthone, diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide, ethyl-(2,4,6-trimethylbenzoyl)phenylphosphinate, 4,4'-bis(diethylamino)benzophenone, 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-1,2-diphenylethan-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 acylphosphine oxide-based photoradical polymerization initiator include 2,4,6-trimethylbenzoyldiphenylphosphine oxide and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide.

[0136] Examples of the oxime ester-based photoradical polymerization initiator include 1-[4-(phenylthio)phenyl]-1,2-octanedione 2-(O-benzoyloxime), 1-[6-(2-methylbenzoyl)-9-ethyl-9H-carbazol-3-yl]ethanone O-acetyloxime, and the like.

[0137] Examples of the α-hydroxyketone-based photoradical polymerization initiator include benzoin, benzoin methyl ether, benzoin butyl ether, 1-hydroxycyclohexyl phenyl 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-hydroxycyclohexyl phenyl ketone.

[0138] The content (blending amount) of the curing catalyst in the 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, relative to 100 parts by mass of the total amount of the curable compounds. When the content of the curing catalyst is 0.01 part by mass or more, the curing reaction can proceed 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 storage stability of the curable composition is improved and coloration of the cured product tends to be suppressed.

[0139] The content (amount) of the cationic polymerization initiator in the 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 the curable compounds. 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 be further improved. When the content is 10 parts by mass or less, the storage stability of the curable composition is improved, and discoloration of the cured product tends to be suppressed.

[0140] The content (blending amount) of the radical polymerization initiator in the curable composition 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 the curable compounds. When the content is 0.1 part by mass or more, the curing reaction can proceed efficiently and sufficiently, and the surface hardness of the cured product tends to be further improved. When the content is 5 parts by mass or less, the storage stability of the curable composition tends to be improved, and discoloration of the cured product tends to be suppressed.

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

[0142] The radically curable polyorganosiloxane has a radically polymerizable functional group in the molecule, such as a photo-radical polymerizable functional group.

[0143] Examples of the photoradical polymerizable functional group include a (meth)acryloyl group, a (meth)acrylamide group, a vinyl group, a vinylthio group, etc. Among these, a (meth)acryloyl group is preferred.

[0144] As the polyorganosiloxane in the radical-curable polyorganosiloxane, a linear polyorganosiloxane is preferred from the viewpoint of exhibiting a greater effect as a leveling agent.

[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, as solid content, per 100 parts by mass of the polyorganosilsesquioxane.

[0146] The curable composition preferably contains an antioxidant. When the curable composition contains an antioxidant, the storage stability of the hard coat layer tends to be further improved. As the antioxidant, only one type may be used, or two or more types may be used.

[0147] As the antioxidant, known or commonly used antioxidants can be used, and although not particularly limited, examples thereof include phenol-based antioxidants, hindered amine-based antioxidants, phosphorus-based antioxidants, and sulfur-based antioxidants.

[0148] Examples of the phenolic antioxidant 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 bisphenols such as 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 polymeric phenols such as tocopherol.

[0149] Examples of the hindered amine antioxidant 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-piperidylsebacate, and 4-benzoyloxy-2,2,6,6-tetramethylpiperidine.

[0150] Examples of the phosphorus-based antioxidant include triphenyl phosphite, diphenyl isodecyl phosphite, phenyl diisodecyl phosphite, tris(nonylphenyl) phosphite, diisodecyl pentaerythritol phosphite, tris(2,4-di-t-butylphenyl) phosphite, cyclic neopentane tetrayl bis(octadecyl) phosphite, cyclic neopentane tetrayl bis(2,4-di-t-butylphenyl) phosphite, cyclic neopentane tetrayl bis(2 ,4-di-t-butyl-4-methylphenyl)phosphite, bis[2-t-butyl-6-methyl-4-{2-(octadecyloxycarbonyl)ethyl}phenyl]hydrogenphosphite, etc.; oxaphosphaphenanthrene oxides such as 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-(3,5-di-t-butyl-4-hydroxybenzyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, etc.

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

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

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

[0154] The curable composition may further contain a solvent. The solvent is not particularly limited as long as it can dissolve the polyorganosilsesquioxane and additives used as needed and does not inhibit polymerization. Only one type of the solvent may be used, or two or more types may be used.

[0155] The solvent used is preferably one that can impart fluidity suitable for application to the hard coat layer and can be easily removed by heating at a temperature that can inhibit the progress of polymerization. It is preferable to use a solvent having a boiling point (at 1 atmosphere) of 170°C or less (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 solvent is preferably used so that the concentration of nonvolatile 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 terms of excellent coatability. However, the amount added should be selected to be an optimal amount adjusted to a viscosity that allows an appropriate film thickness to be achieved, and is not limited to the above range. That is, if the amount of solvent used is excessive, the viscosity of the curable composition will tend to be low, making it difficult to form a coating film of appropriate thickness. On the other hand, if the amount of solvent used is too small, the viscosity of the curable composition will tend to be too high, making it difficult to apply it uniformly to a substrate.

[0157] The curable composition may further contain, as other components, inorganic fillers such as precipitated silica, wet silica, fumed silica, calcined silica, titanium oxide, 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 organohalosilanes, organoalkoxysilanes, and organosilazanes; organic resin fine powders such as silicone resins, epoxy resins, and fluororesins; fillers such as conductive metal powders of silver and copper; curing aids; stabilizers (light resistance stabilizers, heat stabilizers, heavy metal deactivators, and the like); ultraviolet absorbers (triazine-based ultraviolet absorbers, benzotriazole It may also contain conventional additives such as benzophenone-based UV absorbers, oxybenzophenone-based UV absorbers, salicylic acid ester-based UV absorbers, cyanoacrylate-based UV absorbers, flame retardants (phosphorus-based flame retardants, halogen-based flame retardants, inorganic flame retardants, etc.), flame retardant aids, reinforcing materials (other fillers, etc.), nucleating agents, coupling agents (silane coupling agents, etc.), lubricants, waxes, plasticizers, release agents, impact modifiers, color modifiers, clarifying agents, rheology modifiers (flow modifiers, etc.), processability modifiers, colorants (dyes, pigments, etc.), antistatic agents, dispersants, surface modifiers (slip agents, etc.), matting agents, antifoaming agents, foam suppressors, defoaming agents, antibacterial agents, preservatives, viscosity modifiers, thickeners, photosensitizers, and foaming agents. The above other components may be used singly or in combination of two or more. The content of the other components is not particularly limited, but is preferably 100 parts by mass or less, more preferably 30 parts by mass or less (e.g., 0.01 to 30 parts by mass), and even more preferably 10 parts by mass or less (e.g., 0.1 to 10 parts by mass) relative to 100 parts by mass of the total amount of the curable compounds.

[0158] Furthermore, the curable composition preferably does not contain any compounds that fall under PFAS. By having the above-mentioned configuration, the curable composition does not use PFAS and can comply with PFAS regulations.

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

[0160] The curable composition is preferably, but not limited to, a liquid at room temperature (approximately 25°C). More specifically, the viscosity of the curable composition at 25°C when diluted with 20% solvent (particularly a curable composition solution containing 20% by mass of methyl isobutyl ketone) is preferably 300 to 20,000 mPa·s, more preferably 500 to 10,000 mPa·s, and even more preferably 1,000 to 8,000 mPa·s. By adjusting the viscosity to 300 mPa·s or more, the properties of the cured product (coating film) tend to be further improved. On the other hand, by adjusting the viscosity to 20,000 mPa·s or less, the preparation and handling of the curable composition become easier and air bubbles tend to be less likely to remain in the cured product (coating film). The viscosity of the curable composition is measured using a viscometer (trade name "MCR301", manufactured by Anton Paar) under conditions of an oscillation angle of 5%, a frequency of 0.1 to 100 (1 / s), and a temperature of 25°C.

[0161] The hard coat layer can be produced according to a known or commonly used method for producing a hard coat layer, and the method is not particularly limited, but for example, the hard coat layer can be produced by applying the curable composition to at least one surface of the substrate (the surface of the undercoat layer if an undercoat layer is formed), removing the solvent by drying as necessary, and then curing the curable composition (curable composition layer). The method for applying the curable composition and the conditions for curing are not particularly limited, and can be appropriately selected from the conditions described below, for example.

[0162] The hard coat layer can be coated and cured by a conventional coating method. Specifically, the same method as the coating method for the undercoat layer can be used. When the hard coat layer is cured by irradiating it with ultraviolet light, the cumulative irradiation dose is, for example, 1 to 5000 mJ / cm. 2 It is preferable to set it to about this level.

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

[0164] As described above, the curable composition can be applied and cured to form a hard coat layer having high surface hardness and toughness. A transparent laminate including the hard coat layer thus prepared can have excellent flexibility and flexural durability, while also improving the surface hardness of the hard coat layer.

[0165] In order to further improve the recoatability of the hard coat layer, the surface of the hard coat layer may be subjected to a surface treatment such as a corona discharge treatment, which modifies the surface by corona discharge irradiation, a plasma discharge treatment, an ozone exposure treatment, an excimer treatment, etc. Among these, the corona discharge treatment is more preferred because it can easily improve the recoatability.

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

[0167] The haze of the hard coat layer 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%. By keeping the haze at 1% or less, the hard coat layer tends to be suitable for use in applications requiring high transparency.

[0168] The thickness of the hard coat layer is preferably 5 to 100 μm, more preferably 10 to 70 μm. When the thickness of the hard coat layer is 5 μm or more, sufficient surface hardness can be exhibited. Furthermore, when the thickness is 100 μm or less, flexibility can be easily exhibited. Furthermore, when the hard coat layer is formed on both sides of the substrate, the thickness of at least one of the hard coat layers is preferably 5 μm or more, more preferably 10 μm or more. Furthermore, from the viewpoint of exhibiting flexibility, the thickness of each of both hard coat layers is preferably 50 μm or less, more preferably 45 μm or less.

[0169] [Image display device] An embodiment of the present disclosure includes an image display device including the transparent laminate. In the image display device, the transparent laminate is disposed, for example, so that the hard coat layer forms the surface on the viewing side. The image display device is not particularly limited, and examples thereof include organic electroluminescence display devices, inorganic electroluminescence display devices, and liquid crystal display devices. In the display device, the surface of the hard coat layer has sufficient surface hardness, so the surface is less susceptible to scratches and has excellent touchability. Furthermore, since the image display device has excellent flexibility and bending durability, it can also be used as a flexible display that can be rolled, etc. Furthermore, since 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 aspect disclosed in this specification can be combined with any other feature disclosed in this specification. Furthermore, each configuration and their combination in each embodiment is merely an example, and additions, omissions, and other modifications of configurations are possible as appropriate within the scope of the gist of this disclosure. The present disclosure is not limited by the embodiments, but is limited only by the scope of the claims. [Example]

[0171] Hereinafter, one embodiment of the present disclosure will be described in more detail based on examples.

[0172] Manufacturing Example 1 (Production 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 heated to 50°C. To the resulting mixture, 7.74 g of 5% aqueous potassium carbonate solution (2.8 mmol of potassium carbonate) was added over 5 minutes, followed by the addition of 2800.0 mmol (50.40 g) of water over 20 minutes. No significant temperature increase occurred during the addition. The polycondensation reaction was then carried out under a nitrogen stream at 50°C for 5 hours. The reaction solution was then cooled, and 137.70 g of methyl isobutyl ketone and 100.60 g of 5% saline were added. This solution was transferred to a 1 L separatory funnel, and 137.70 g of methyl isobutyl ketone was added again, followed by washing with water. After separation, the aqueous layer was removed and washed with water until the lower layer became neutral. The upper layer was separated, and the solvent was distilled off from the upper layer at 1 mmHg and 50 ° C. to obtain 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. Analysis of the product revealed that the number average molecular weight was 2235 and the molecular weight dispersity 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 The results were confirmed by Si-NMR. The molecular weight of the product was measured using a Shimadzu LC-20AD pump, a Shodex RI-504 detector, Shodex GPC KF-602 and KF-603 columns, a Shodex GPC KF-G guard column, THF solvent, and a measurement condition of 40°C. The ratio of T2 to T3 isomers in the product [T3 / T2 isomer] was measured using a JEOL ECA500 (500 MHz). 29 This was measured by Si-NMR spectroscopy.

[0173] (Preparation of hard coating agent) Hard coating agents were prepared by mixing the above-mentioned silsesquioxane with each material in the composition ratio shown in Table 1. The content ratios shown in Tables 1 to 7 are the blending ratios of each component, and are solution values for silsesquioxane (77% by mass of active ingredient) and RS-57 (20% by mass of active ingredient), and values for the other components are the active ingredient values.

[0174] [Table 1]

[0175] Example 1 A primer called "CELV B0955" (manufactured by Daicel Corporation) was applied to a surface of chemically strengthened UTG (manufactured by Nippon Electric Glass Co., Ltd., thickness 90 μm) using a wire bar #5 to a thickness of 5 μm, and then 300 mJ / cm was applied using a high-pressure mercury lamp. 2 The hard coating agent was then applied onto the primer using a wire bar #30 so that the thickness after curing was 25 μm, and the applied hard coating agent was then left in an oven at 80° C. for 1 minute and then in an oven at 120° C. for 2 minutes. Next, a high-pressure mercury lamp was used to apply ultraviolet light at an illuminance of 300 mJ / cm. 2 After that, the film was left in an oven at 120° C. for 60 minutes to prepare a transparent laminate of Example 1.

[0176] Example 2 A transparent laminate of Example 2 was produced in the same manner as in Example 1, except that a hard coating agent having the blending ratio shown in Table 2 was used.

[0177] [Table 2]

[0178] Example 3 A transparent laminate of Example 3 was produced in the same manner as in Example 1, except that a hard coating agent having the blending ratio shown in Table 3 was used.

[0179] [Table 3]

[0180] Example 4 A transparent laminate of Example 4 was produced in the same manner as in Example 1, except that a hard coating agent having the blending ratio shown in Table 4 was used.

[0181] [Table 4]

[0182] Example 5 A transparent laminate of Example 5 was produced in the same manner as in Example 1, except that a hard coating agent having the blending ratio shown in Table 5 was used.

[0183] [Table 5]

[0184] Comparative Example 1 A transparent laminate of Comparative Example 1 was produced in the same manner as in Example 1, except that a hard coating agent having the blending ratio shown in Table 6 was used.

[0185] [Table 6]

[0186] Comparative Example 2 A transparent laminate of Comparative Example 2 was produced in the same manner as in Example 1, except that a hard coating agent having the blending ratio shown in Table 7 was used.

[0187] [Table 7]

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

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

[0190] [evaluation] The transparent laminates produced in the Examples and Comparative Examples and the glass substrate of the Reference Example were evaluated as follows. The results are shown in Table 8.

[0191] (1) Microhardness measurement The surface of the hard coat layer of the transparent laminate produced in the Examples and Comparative Examples was measured at 10 points using a nanoindenter (product name "ENT-2100", manufactured by Elionix Co., Ltd.) as a Berkovich indenter with a maximum load of 500 μN, and the average values of the indentation modulus and indentation hardness were measured. The ratio of the indentation modulus to the 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 produced in the examples and comparative examples was evaluated in accordance with JIS K5600-5-4 (750 g load).

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

[0194] [Table 8]

[0195] The transparent laminates of the examples had pencil hardnesses of H or higher, minimum bendable radii of 1.5 mm or less when subjected to a cylindrical mandrel test with the hard coat layer side concave, and a ratio of indentation modulus to indentation hardness in microhardness measurements of 6.0 or higher, allowing the production of transparent laminates with excellent flexibility while maintaining high hardness. On the other hand, when the ratio of indentation modulus to indentation hardness in microhardness measurements 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 according to the present disclosure are described below. [Appendix 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 load of 750 g is H or more; the minimum bendable radius when a cylindrical mandrel test is performed with the surface of the hard coat layer of the transparent laminate made concave is 1.5 mm or less; A transparent laminate in which the ratio of the indentation elastic modulus to the indentation hardness (indentation elastic modulus / indentation hardness) in a microhardness test of the transparent laminate is 6.0 or more. [Appendix 2] 2. The transparent laminate according to claim 1, wherein the hard coat layer has a haze of 1.0% or less. [Appendix 3] the hard coat layer is a cured product of a curable composition containing one or more curable compounds, 3. The transparent laminate according to claim 1, wherein the curable compound comprises an aliphatic compound having two or more cationically polymerizable groups in the molecule. [Appendix 4] 4. The transparent laminate according to claim 3, wherein the curable compound is polyorganosilsesquioxane. [Appendix 5] 5. The transparent laminate according to claim 3, wherein the curable compound comprises two or more of the aliphatic compounds. [Appendix 6] 6. The transparent laminate according to any one of claims 3 to 5, wherein the curable composition further contains a curing catalyst. [Appendix 7] 7. The transparent laminate according to claim 6, wherein the curing catalyst comprises a cationic polymerization initiator. [Appendix 8] 8. The transparent laminate according to claim 6, wherein the curing catalyst comprises a radical polymerization initiator. [Appendix 9] 9. The transparent laminate according to any one of claims 1 to 8, wherein the hard coat layer does not contain any compound that falls under PFAS. [Appendix 10] 10. The transparent laminate according to any one of claims 1 to 9, having a surface protection film on at least one surface. [Appendix 11] 11. The transparent laminate according to any one of claims 1 to 10, wherein the hard coat layer is provided on one surface of the substrate, and an adhesive layer is provided on the other surface. [Appendix 12] 12. The transparent laminate according to any one of claims 1 to 11, wherein the substrate is glass having a thickness of 30 to 100 μm. [Appendix 13] An image display device comprising the transparent laminate according to any one of claims 1 to 12. [Appendix 14] 14. The image display device according to claim 13, which is a flexible display. [Appendix 15] 15. The image display device according to claim 13 or 14, which is an organic electroluminescence display device. [Appendix 16] A flexible device comprising the image display device according to any one of 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 load of 750 g is H or more; the minimum bendable radius when a cylindrical mandrel test is performed with the surface of the hard coat layer of the transparent laminate made concave is 1.5 mm or less; The transparent laminate has a ratio of indentation elastic modulus to indentation hardness (indentation elastic modulus / indentation hardness) of 6.0 or more in a microhardness test.

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

3. the hard coat layer is a cured product of a curable composition containing one or more curable compounds, 3. The transparent laminate according to claim 1, wherein the curable compound comprises an aliphatic compound having two or more cationically polymerizable groups in the molecule.

4. The transparent laminate according to claim 3 , wherein the curable compound comprises polyorganosilsesquioxane.

5. The transparent laminate according to claim 3 , wherein the curable compound contains two or more kinds of the aliphatic compound.

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

7. The transparent laminate according to claim 6 , wherein the curing catalyst comprises a cationic polymerization initiator.

8. The transparent laminate according to claim 6 , wherein the curing catalyst comprises a radical polymerization initiator.

9. 3. The transparent laminate according to claim 1, wherein the hard coat layer does not contain any compound that falls under PFAS.

10. 3. The transparent laminate according to claim 1, which has a surface protection film on at least one surface.

11. 3. The transparent laminate according to claim 1, wherein the hard coat layer is provided on one surface of the substrate, and an adhesive layer is provided on the other surface.

12. 3. The transparent laminate according to claim 1, wherein the substrate is a glass substrate having a thickness of 30 to 100 μm.

13. An image display device comprising the transparent laminate according to claim 1 or 2.

14. The image display device according to claim 13, which is a flexible display.

15. 14. The image display device according to claim 13, which is an organic electroluminescence display device.

16. A flexible device comprising the image display device according to claim 13.

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