Laminate, laminated film, image display device, and foldable device

Abstract

To provide a laminate that can exhibit sufficient bendability without using a compound corresponding to a PFAS.SOLUTION: A laminate of the present disclosure includes a substrate and a hard coat layer laminated on at least one surface of the substrate. The hard coat layer contains no compound corresponding to a PFAS. The laminate of the present disclosure is further characterized in that a minimum bendable radius is equal to or less than 5 mm in a cylindrical mandrel test in which the laminate is bent with the surface of the hard coat layer of the laminate being convex. In addition, in a bending durability test of the hard coat layer, the number of operations until a crack occurs in the hard coat layer is preferably 10000 or more.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a laminate, a laminate film, an image display device, and a foldable device. [Background technology]

[0002] A hard coat layer is known to be laminated on the outermost surface of the display and electronic materials of televisions, personal computers, smartphones, etc. to prevent scratches. In particular, UV-curable resins containing cross-linkable fluorine compounds (PFAS) have traditionally been used for such hard coat layers to provide abrasion resistance (see, for example, Patent Document 1).

[0003] However, PFASs are poorly degradable and there are concerns about their long-term persistence in the environment and toxicity. From the perspective of reducing the burden on the environment, there has been a demand for hard coating layers that do not contain PFASs. [Prior art documents] [Non-patent literature]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-11365 Summary of the Invention [Problem to be solved by the invention]

[0005] However, PFAS-free hard coat layers have insufficient flexibility, and it has been difficult to create a hard coat layer that exhibits the same flexibility as PFAS-containing products.

[0006] The present disclosure is intended to solve the above-mentioned problems, and its purpose is to provide a laminate that can exhibit sufficient flexibility without using compounds that fall under PFAS. [Means for solving the problem]

[0007] The inventors of the present disclosure have found that a laminate having a substrate and a hard coat layer laminated on at least one surface of the substrate, where the hard coat layer does not contain compounds that fall under PFAS and satisfies certain physical properties, can exhibit sufficient flexibility without using a fluorine compound. The present disclosure has been completed based on these findings.

[0008] The present disclosure provides a laminate having a substrate and a hard coat layer laminated on at least one surface of the substrate, wherein the hard coat layer does not contain compounds that fall under PFAS, and wherein the laminate has a minimum bendable radius of 5 mm or less in a cylindrical mandrel test in which the laminate is bent so that the surface of the hard coat layer is convex.

[0009] The laminate preferably has a hard coat layer that can be operated 10,000 times or more before cracks appear in the hard coat layer in the flexural durability test described below. By having the above configuration, the laminate can have better flexural durability. Flexural durability test: From the stretched state, the laminate is bent 180° in the direction in which the hard coat layer surface is convex so that the bending radius is 4.0 mm, and then stretched again. This operation counts as one cycle, and is performed at a speed of 30 to 60 / min.

[0010] The laminate was spun to a thickness of 750 g / cm using #0000 steel wool. 2 It is preferable that no scratches are visually observed in a steel wool resistance test in which the surface of the hard coat layer is rubbed back and forth 1000 times while applying a load of 1000. By having the above configuration, it is possible to obtain a product with even better scratch resistance.

[0011] In the laminate, the hard coat layer preferably has a haze of 1.0% or less.

[0012] The laminate preferably has a haze of 7% or less.

[0013] Furthermore, 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 polyorganosilsesquioxane.

[0014] The curable composition preferably contains a compound having one or more cationically polymerizable groups and one or more radically polymerizable groups in the molecule.

[0015] The curable composition preferably further contains a curing catalyst.

[0016] The curing catalyst preferably contains a cationic polymerization initiator.

[0017] The curing catalyst preferably contains a radical polymerization initiator.

[0018] It is preferable that the curable composition further contains a radical-curable polyorganosiloxane.

[0019] It is preferable that the curable composition further contains an aliphatic compound having two or more cationically polymerizable groups in the molecule.

[0020] The substrate is preferably a transparent substrate.

[0021] The laminate preferably has a surface protection film on at least one surface.

[0022] The laminate preferably has the hard coat layer on one surface of the substrate and an adhesive layer on the other surface.

[0023] The present disclosure also provides an image display device including the above laminate.

[0024] The image display device is preferably a foldable display.

[0025] The image display device is preferably an organic electroluminescence display device.

[0026] The present disclosure also provides a foldable device including the image display device. [Effects of the Invention]

[0027] The laminate of the present disclosure can exhibit sufficient flexibility without using compounds that fall under PFAS. DETAILED DESCRIPTION OF THE INVENTION

[0028] In this disclosure, "compounds that fall under PFAS" is a general term for perfluoroalkyl compounds and polyfluoroalkyl compounds.

[0029] [Laminate] The laminate of the present disclosure has a substrate and a hard coat layer laminated on at least one surface of the substrate, the hard coat layer does not contain compounds that fall under PFAS, and in a cylindrical mandrel test in which the laminate is bent so that the surface of the hard coat layer is convex, the minimum bendable radius is 5 mm or less. The laminate of the present disclosure having the above configuration can exhibit sufficient flexibility without containing compounds that fall under PFAS.

[0030] The 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 or compositions may be laminated on each surface.

[0031] The surface protective film protects the surface of the hard coat layer, and the laminate preferably has a surface protective film on at least one surface. In addition, when the hard coat layer is formed on both surfaces of the substrate, the laminate may have the surface protective film on both surfaces.

[0032] 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.

[0033] 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.).

[0034] In the laminate, the adhesive layer is preferably laminated on the surface opposite to the surface on which the hard coat layer of the substrate is laminated. That is, when the 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. Furthermore, it is more preferable that the laminate has the adhesive layer on the surface of one side.

[0035] 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.

[0036] 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.

[0037] The adhesive layer can be obtained by applying the adhesive to at least one surface of the substrate and curing it.

[0038] In a cylindrical mandrel test conducted in accordance with JIS K5600-5-1 in which the laminate is bent so that the surface of the hard coat layer is convex, the minimum bending diameter at which cracks do not occur is in the range of 5 mm or less, preferably 4 mm or less. By having the minimum bending diameter of 5 mm or less, sufficient flexibility can be exhibited. When hard coat layers are laminated on both sides of the laminate, it is sufficient that the above range is satisfied on at least one side.

[0039] The laminate preferably has a minimum bending diameter of 5 mm or less, more preferably 4 mm or less, and even more preferably 2 mm or less, at which cracks do not occur in a cylindrical mandrel test, similarly conducted in accordance with JIS K5600-5-1, in which the laminate is bent so that the surface of the hard coat layer is concave. By having the minimum bending diameter of 5 mm or less, sufficient flexibility can be exhibited. When hard coat layers are laminated on both sides of the laminate, it is sufficient that the minimum bending diameter satisfies the above range on at least one side.

[0040] The laminate preferably has a pencil hardness of F or more, more preferably H or more, measured in accordance with JIS K5600-5-4. A pencil hardness of F or more ensures that the surface hardness of the laminate is sufficient, making it easier to exhibit abrasion resistance. When hard coat layers are laminated on both sides of the laminate, it is sufficient that the hard coat layer satisfies the above range on at least one side.

[0041] In a bending durability test in which the laminate is stretched, folded 180° in a direction so that the hard coat layer surface is convex with a bending radius of 4.0 mm, and then stretched again, this cycle is counted as one cycle, and the above cycle is performed at a speed of 30 to 60 cycles per minute. In this test, the laminate preferably undergoes 10,000 cycles or more before cracks appear in the hard coat layer, and more preferably 30,000 cycles or more before cracks appear. By having the above configuration, sufficient bending durability can be exhibited. Note that, when hard coat layers are laminated on both sides of the laminate, it is sufficient that the above range is satisfied on at least one side.

[0042] In addition, the laminate was subjected to a load of 750 g / cm2 of #0000 steel wool on the surface of the hard coat layer. 2 It is preferable that no scratches are found on the surface of the hard coat layer when the hard coat layer is reciprocated 1000 times at a temperature of 1000°C. By having the above-mentioned constitution, abrasion resistance can be exhibited.

[0043] The haze value of the laminate is preferably 7% or less, more preferably 5% or less, even more preferably 3% or less, and particularly preferably 1.5% or less. The lower limit of the haze is, for example, 0.1%. By keeping the haze at 7% or less, the laminate tends to be suitable for use in applications requiring high transparency. In this specification, the haze can be measured in accordance with JIS K7136.

[0044] The total light transmittance of the laminate is preferably 85% or more, more preferably 90% or more. By setting the total light transmittance to 85% or more, the laminate tends to be suitable for use in applications requiring high transparency. In this specification, the total light transmittance can be measured in accordance with JIS K7361-1.

[0045] The thickness of the laminate is preferably 10 to 1000 μm, more preferably 30 to 500 μm, and particularly preferably 50 to 300 μm. When the thickness of the laminate is 10 μm or more, it becomes easy to achieve sufficient surface hardness. Furthermore, when the thickness is 1000 μm or less, it becomes easy to exhibit sufficient flexibility.

[0046] <Base material> The substrate in the 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, the substrate is preferably a transparent substrate, and a plastic substrate is preferred. The substrate may have a single-layer structure or a multi-layer structure, and may be made of one material or two or more materials.

[0047] The plastic material constituting the plastic substrate is not particularly limited, and examples thereof include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); polyimide; polycarbonate; polyamide; polyacetal; polyphenylene oxide; polyphenylene sulfide; polyether sulfone; polyether ether ketone; homopolymers of norbornene-based monomers (addition polymers, ring-opening polymers, etc.), copolymers of norbornene-based monomers and olefin-based monomers (cyclic olefin copolymers such as addition polymers and ring-opening polymers, etc.), such as copolymers of norbornene and ethylene, and cyclic polyolefins such as derivatives thereof; vinyl polymers (e.g., acrylic resins such as polymethyl methacrylate (PMMA), polystyrene, polyvinyl chloride, acrylonitrile-styrene-butadiene resin (ABS resin)); vinylidene polymers (e.g., polyvinylidene chloride); cellulose-based resins such as triacetyl cellulose (TAC); epoxy resins; phenolic resins; melamine resins; urea resins; maleimide resins; and silicones.

[0048] Among these, it is preferable to use a substrate having excellent transparency and bending durability as the plastic substrate, and more preferable are polyester films (particularly PET and PEN), polyimide films, cyclic polyolefin films, polycarbonate films, TAC films, and PMMA films, and even more preferable are polyester films (particularly PET and PEN) and polyimide films.

[0049] The substrate may contain, as necessary, other additives such as antioxidants, ultraviolet absorbers, light stabilizers, heat stabilizers, crystal nucleating agents, flame retardants, flame retardant assistants, fillers, plasticizers, impact modifiers, reinforcing agents, dispersants, antistatic agents, foaming agents, antibacterial agents, etc. Only one type of additive may be used, or two or more types may be used.

[0050] A part or all of the surface of the substrate on which the hard coat layer is laminated may be subjected to a known or conventional surface treatment such as a roughening treatment, an easy-adhesion treatment, an antistatic treatment, a sandblasting treatment (sand matting), a corona discharge treatment, a plasma treatment, a chemical etching treatment, a water matting treatment, a flame treatment, an acid treatment, an alkali treatment, an oxidation treatment, an ultraviolet irradiation treatment, or a silane coupling agent treatment. The plastic substrate may be an unstretched film or a stretched film such as a uniaxially stretched film or a biaxially stretched film. Commercially available products may also be used as the substrate.

[0051] The thickness of the substrate is, for example, preferably 1 to 1000 μm, more preferably 5 to 500 μm, even more preferably 10 to 400 μm, and particularly preferably 10 to 300 μm.

[0052] <Hard coat layer> In the laminate, even when the hard coat layer is formed on only one surface (one side) of the substrate, it preferably has sufficient surface hardness while suppressing the occurrence of cracks in the laminate. The hard coat layer may be formed on both surfaces (both surfaces) of the substrate. However, when the laminate has the adhesive layer, it is preferably formed on only one surface of the substrate. When hard coat layers are formed on both surfaces of the substrate, it is sufficient that at least one surface satisfies the physical properties of the hard coat layer described below. The hard coat layers may be identical to each other, or layers with different thicknesses and compositions may be laminated. 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 the occurrence of cracks, 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.

[0053] 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.

[0054] Examples of the curable compound include (meth)acrylate compounds, curable silicone compounds, epoxy compounds, melamine compounds, vinyl ether compounds, and oxetane compounds. Among these, it is preferable to include a curable silicone compound. As the curable silicone compound, it is more preferable to include a silsesquioxane, and it is particularly preferable to include a polyorganosilsesquioxane. By including the polyorganosilsesquioxane, the curable composition is less likely to shrink during curing, thereby providing a hard coat layer with superior abrasion resistance. Furthermore, the silsesquioxane may be a radical polymerizable silsesquioxane or a cationically polymerizable silsesquioxane. Among these, it is preferable to use a cationically polymerizable silsesquioxane. It is more preferable that the cationically polymerizable silsesquioxane is a photocationically polymerizable silsesquioxane.

[0055] The radically polymerizable silsesquioxane 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.

[0056] The cationically polymerizable silsesquioxane 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.

[0057] 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]

[0058] In the above formula (1a), R 1a represents 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.

[0059] 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.

[0060] In the above formula (1c), R 1c represents a linear or branched alkylene group, and R 1a Among them, R 1cFrom 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.

[0061] In the above formula (1d), R 1d represents a linear or branched alkylene group, and R 1a Among them, R 1d 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.

[0062] 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.

[0063] Examples of the cationically polymerizable silsesquioxane include compounds having a constitutional unit represented by the following formula (1). [R 1 SiO 3 / 2 ] (1)

[0064] 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.

[0065] 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).

[0066] 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 be contained as the constitutional unit represented by the above formula (1). [R 2 SiO 3 / 2 ] (2)

[0067] 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.

[0068] 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.

[0069] 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).

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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 / 2In 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)

[0074] 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 SiO 2 / 2 (OR c )] (II)

[0075] 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]

[0076] 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) b are 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).

[0077] 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).

[0078] 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.

[0079] The molar ratio [T3 isomer / T2 isomer] in the silsesquioxane (X) is, for example, 29 It can be determined by Si-NMR spectroscopy. 29 In 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).

[0080] 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℃

[0081] 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)

[0082] The cationically polymerizable silsesquioxane (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.

[0083] 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 -1When a silsesquioxane has one characteristic absorption peak in the vicinity, it is suggested that the silsesquioxane has an incomplete cage silsesquioxane structure.

[0084] 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 -1 In 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

[0085] 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 (total siloxane structural units; the total amount of M units, D units, T units, and Q units) in the cationically polymerizable silsesquioxane (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%. A proportion of 50 mol% or more improves the curability of the curable composition and significantly increases the surface hardness of the hard coating layer. The proportion of each siloxane structural unit in the cationically polymerizable silsesquioxane can be calculated, for example, from the composition of the raw materials or NMR spectroscopy.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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, or 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, compatibility with other components in the curable composition is improved, and the heat resistance of the hard coat layer tends to be improved.

[0090] 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.

[0091] 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

[0092] The cationically polymerizable silsesquioxane can be produced by a known or conventional method for producing silsesquioxane, and is not particularly limited. For example, the cationically polymerizable silsesquioxane can be produced by a method in which one or more hydrolyzable silane compounds are hydrolyzed and condensed.

[0093] 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.

[0094] The curable composition preferably contains 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"). By containing compound A, the curable composition can effectively increase the crosslink density when cured, making it easier to impart high surface hardness and excellent flexibility and flexural durability to the hard coat layer, and making it possible to prevent deterioration of antifouling performance. Only one type of compound A may be used, or two or more types may be used.

[0095] Examples of the "cationically polymerizable group" possessed by Compound A include an epoxy group, an oxetanyl group, a vinyl ether group, and a hydroxyl group, and from the viewpoint of preventing 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.

[0096] 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.

[0097] 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.

[0098] 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]

[0099] 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]

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] 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.

[0105] 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)). By containing compound B, flexibility can be imparted to the hard coat layer, making it easier to exhibit flexural and flexural durability. Note that compound (B) is a compound that does not fall under the category of polyorganosilsesquioxane or compound (A). As compound (B), only one type may be used, or two or more types may be used.

[0106] The cationically polymerizable group may be the same as that exemplified in the compound (A). For example, an epoxy group, an oxetanyl group, a vinyl ether group, etc. may be mentioned. From the viewpoint of exhibiting the surface hardness, flexibility, and flexural durability of the hard coat layer, an epoxy group is preferred, and from the viewpoint of reactivity, a glycidyl group is more preferred. The two or more cationically polymerizable groups possessed by the compound B may be the same or different.

[0107] 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.

[0108] 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 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 B can be calculated by the following formula. [Functional group equivalent of cationically polymerizable group]=[Molecular weight of compound B] / [Number of thermally polymerizable functional groups contained in compound B]

[0109] 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.

[0110] Compound B is preferably a compound having cationically polymerizable groups at both ends, and specifically, is preferably an aliphatic glycidyl ether type epoxy compound.

[0111] Examples of the aliphatic glycidyl ether type epoxy compound include (poly)alkylene glycol diglycidyl ethers such as ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, and triethylene glycol diglycidyl ether, and diol diglycidyl ethers such as 1,6-hexanediol diglycidyl ether. Commercially available aliphatic glycidyl ether type epoxy compounds include those under the trade names "EPOLITE 40E," "EPOLITE 100E," "EPOLITE 200E," "EPOLITE 400E," and "EPOLITE 1600N" (manufactured by Kyoeisha Chemical Co., Ltd.), and those under the trade name "YH-300" (manufactured by Nippon Steel Chemical & Material Co., Ltd.).

[0112] The content of compound (B) in the curable composition is not particularly limited, but is preferably 1 to 20 mass %, more preferably 2 to 15 mass %, and even more preferably 3 to 10 mass %, relative to the total amount (100 mass %) of the curable compounds. When the content is within the above range, the flexibility and flex resistance of the hard coat layer become more appropriate.

[0113] The content of compound (B) is not particularly limited, but is preferably 1 to 20 parts by mass, more preferably 2 to 15 parts by mass, and even more preferably 3 to 10 parts by mass, relative to 100 parts by mass of the polyorganosilsesquioxane. When the content is within the above range, the flexibility and flex resistance of the hard coat layer become more appropriate.

[0114] The curable composition preferably contains a curing catalyst. The curing catalyst is a compound that can initiate or accelerate the polymerization reaction of curable compounds such as the polyorganosilsesquioxane, compound (A), and compound (B). Only one type of curing catalyst may be used, or two or more types may be used.

[0115] 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.

[0116] Examples of the cationic polymerization initiator include a photo-cationic polymerization initiator (photo-acid generator) and a thermal cationic polymerization initiator (thermal acid generator).

[0117] 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.

[0118] 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.

[0119] 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.

[0120] 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.

[0121] 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.

[0122] 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.

[0123] 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.

[0124] 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.

[0125] 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.

[0126] 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.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] 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.

[0131] Examples of the acylphosphine oxide-based photoradical polymerization initiator include 2,4,6-trimethylbenzoyldiphenylphosphine oxide and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide.

[0132] 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.

[0133] 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.

[0134] 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.

[0135] The content (amount) of the cationic polymerization initiator in the curable composition is not particularly limited, but is preferably 0.005 to 10 parts by mass, more preferably 0.01 to 5 parts by mass, even more preferably 0.015 to 3 parts by mass, and particularly preferably 0.02 to 2 parts by mass, per 100 parts by mass of the total amount of the curable compounds. When the content is 0.005 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 tends to be improved, and discoloration of the cured product tends to be suppressed.

[0136] The content (blending amount) of the radical polymerization initiator in the curable composition is not particularly limited, but is preferably 0.01 to 5 parts by mass, more preferably 0.03 to 3 parts by mass, and even more preferably 0.05 to 2 parts by mass, relative to 100 parts by mass of the total amount of the curable compounds. When the content is 0.01 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.

[0137] The curable composition preferably contains a radical-curable polyorganosiloxane as a leveling agent. By using the radical-curable polyorganosiloxane, the smoothness of the hard coat layer surface can be improved while exhibiting flexibility and flexural durability. In addition, the radical-curable polyorganosiloxane is preferably not PFAS. In this case, the above-mentioned effects can be exhibited while not being PFAS. The radical-curable polyorganosiloxane may be used alone or in combination of two or more.

[0138] The radically curable polyorganosiloxane has a radically polymerizable functional group in the molecule, such as a photo-radical polymerizable functional group.

[0139] 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.

[0140] 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.

[0141] The content of the radical curable polyorganosiloxane is not particularly limited, but is preferably 0.01 to 5 parts by mass, more preferably 0.03 to 3 parts by mass, and even more preferably 0.05 to 2 parts by mass, relative to 100 parts by mass of the polyorganosilsesquioxane.

[0142] 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.

[0143] 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.

[0144] 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.

[0145] 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.

[0146] 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.

[0147] Examples of the sulfur-based antioxidant include dodecanethiol, dilauryl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, and distearyl-3,3'-thiodipropionate.

[0148] 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.

[0149] 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.

[0150] 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.

[0151] 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).

[0152] 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.

[0153] 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.

[0154] Furthermore, the curable composition does not contain any compounds that fall under the category of PFAS. By having the above-mentioned configuration, the composition is PFAS-free and can comply with PFAS regulations.

[0155] 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.

[0156] 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.

[0157] 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, 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.

[0158] The hard coat layer can be coated and cured 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. Curing methods include, for example, light irradiation using a mercury lamp, xenon lamp, carbon arc lamp, metal halide lamp, sunlight, an electron beam source, a laser light source, and an LED light source. When ultraviolet light is irradiated to cure the hard coat layer, the cumulative irradiation dose is, for example, 1 to 5,000 mJ / cm. 2 It is preferable to set it to about this level.

[0159] 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.

[0160] As described above, the curable composition can be applied and cured to form a hard coat layer having high surface hardness and toughness. A 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.

[0161] 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.

[0162] 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.

[0163] 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.

[0164] 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 60 μm or less, more preferably 50 μm or less.

[0165] [Image display device] An embodiment of the present disclosure includes an image display device including the laminate. In the image display device, the laminate is arranged, 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 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, making the surface less susceptible to scratches and providing excellent touchability. Furthermore, since the image display device has excellent flexibility and bending durability, it can also be used as a foldable display that can be rolled up, etc. Furthermore, since it has sufficient surface hardness, flexibility, and bending durability, it can also be suitably used as a foldable device including the image display device.

[0166] 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]

[0167] Hereinafter, one embodiment of the present disclosure will be described in more detail based on examples.

[0168] 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 of Production Example 1) containing 23 mass% 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). 29This was measured by Si-NMR spectroscopy.

[0169] (Preparation of hard coating agent) Hard coating agents of Examples and Comparative Examples were prepared by mixing each material with the silsesquioxane in the composition ratios shown in Table 1. The content ratios shown in the table are the blending ratios of each component, and are solution values for the silsesquioxane of Production Example 1 (77% by mass of active ingredient) and RS-57 (20% by mass of active ingredient), and values for the other components are the active ingredients.

[0170] [Table 1]

[0171] Each component used in Table 1 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 groups and one or more radically polymerizable groups in the molecule) Epolight 1600N: Product name "Epolight 1600N", manufactured by Kyoeisha Chemical Co., Ltd. (an aliphatic compound having two or more cationic polymerizable groups in the molecule) Omnirad127: Product name "Omnirad127", manufactured by IGM Resins BV (radical polymerization initiator) Triarylsulfonium and tetrapentafluorophenylgallium salts: Photocationic polymerization initiators. ADK STAB AO-02: Product name "ADK STAB AO-02", manufactured by ADEKA Corporation (antioxidant) KY1203: Product name "KY1203", containing compounds that fall under PFAS, manufactured by Shin-Etsu Chemical Co., Ltd. (leveling agent) RS-57: Product name "RS-57", a silicone resin that does not contain PFAS compounds, manufactured by DIC Corporation (leveling agent) MIBK: Methyl isobutyl ketone (solvent) MEK: Methyl ethyl ketone (solvent)

[0172] Examples 1 and 2 The hard coating agent of the above example was applied to a PET substrate (product name "TA069", manufactured by Toyobo Co., Ltd.) using wire bars #12 and #22 so that the thickness after curing would be 10 μm and 20 μm, respectively, and then the coating was 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 300 mJ / cm 2 After that, the laminate was left in an oven at 120° C. for 60 minutes to prepare the laminates of Examples 1 and 2.

[0173] Comparative Examples 1 and 2 The laminates of Comparative Examples 1 and 2 were produced in the same manner as the laminates of Examples 1 and 2, except that the hard coating agent of the above comparative example was applied to a PET substrate (product name "TA069", manufactured by Toyobo Co., Ltd.) using wire bars #12 and #22 so that the thickness after curing would be 10 μm and 20 μm, respectively.

[0174] [evaluation] The laminates produced in the examples and comparative examples were evaluated as follows, and the results are shown in Table 2.

[0175] (1) Hayes The haze values (%) of the laminates of Examples 1 and 2 and Comparative Examples 1 and 2 were measured using a haze measuring device (trade name "NDH-5000W", manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with JIS K7136.

[0176] (2) Total light transmittance The total light transmittance (%) of the laminates of Examples 1 and 2 and Comparative Examples 1 and 2 was measured using a total light transmittance measuring device (trade name "NDH-5000W", manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with JIS K7105.

[0177] (3) Pencil hardness The pencil hardness of the hard coat layer surface of the laminates of Examples 1 and 2 and Comparative Examples 1 and 2 was evaluated in accordance with JIS K5600-5-4 (750 g load).

[0178] (4) Abrasion resistance For the laminates of Examples 1 and 2 and Comparative Examples 1 and 2, #0000 steel wool was applied to the hard coat layer surface at a load of 750 g / cm 2 The hard coat layer was checked for scratches on its surface after the test.

[0179] (5) Flexibility For the laminates of Examples 1 and 2 and Comparative Examples 1 and 2, the flexibility was measured both when the hard coat layer was on the inside and when it was on the outside using a cylindrical mandrel bending tester (product name "Bending Tester (Cylindrical Mandrel Method)", manufactured by TP Giken Co., Ltd.) according to JIS K5600-5-1 (1999).

[0180] (6) Continuous bending durability The laminates of Examples 1 and 2 and Comparative Examples 1 and 2 were subjected to continuous bending durability testing using a sheet-shaped unloaded U-shaped stretch tester (product name "Z-044", manufactured by Yuasa System Co., Ltd.) The measurement was performed 10,000 times at a speed of 30 to 60 times per minute, with the hard coat layer facing the convex side and bending 180° to a bending radius of 4.0 mm and then stretching again, counting each cycle as one cycle. The hard coat layer and the PET substrate were then examined for cracks.

[0181] [Table 2]

[0182] The laminate of the example exhibited similar hardness and flexibility to the laminate of the comparative example, which used a compound corresponding to PFAS, and it was confirmed that the laminate of the example exhibited sufficient abrasion resistance and flexibility without using a fluorine compound.

[0183] Variations of the invention according to the present disclosure are described below. [Appendix 1] A substrate and a hard coat layer laminated on at least one surface of the substrate, The hard coat layer is a laminate containing no compounds that fall under PFAS, A laminate having a minimum bending radius of 5 mm or less in a cylindrical mandrel test in which the laminate is bent so that the surface of the hard coat layer thereof is convex. [Appendix 2] Attachment 1: The laminate according to claim 1, wherein the hard coat layer can withstand 10,000 or more bending cycles before cracks appear in the hard coat layer in the following bending durability test. Flexural durability test: From the stretched state, the laminate is bent 180° in the direction in which the hard coat layer surface is convex so that the bending radius is 4.0 mm, and then stretched again. This operation counts as one cycle, and is performed at a speed of 30 to 60 / min. [Appendix 3] The hard coat layer is 750 g / cm with #0000 steel wool. 2 3. The laminate according to claim 1 or 2, wherein the surface of the hard coat layer is rubbed back and forth 1000 times while applying a load of 1000 to 1000 times to a steel wool resistance test, and no scratches are observed visually. [Appendix 4] 4. The laminate according to any one of claims 1 to 3, wherein the hard coat layer has a haze of 1.0% or less. [Appendix 5] 5. The laminate according to any one of claims 1 to 4, having a haze of 7% or less. [Appendix 6] 6. The laminate according to any one of claims 1 to 5, wherein the hard coat layer is a cured product of a curable composition containing one or more curable compounds, and the curable compound contains polyorganosilsesquioxane. [Appendix 7] 7. The laminate according to claim 6, wherein the curable composition contains a compound having one or more cationically polymerizable groups and one or more radically polymerizable groups in the molecule. [Appendix 8] 8. The laminate according to claim 6, wherein the curable composition further comprises a curing catalyst. [Appendix 9] 9. The laminate according to claim 8, wherein the curing catalyst comprises a cationic polymerization initiator. [Appendix 10] 10. The laminate according to claim 8, wherein the curing catalyst comprises a radical polymerization initiator. [Appendix 11] 11. The laminate according to any one of claims 6 to 10, wherein the curable composition further contains a radically curable polyorganosiloxane. [Appendix 12] 12. The laminate according to any one of claims 6 to 11, wherein the curable composition further contains an aliphatic compound having two or more cationically polymerizable groups in the molecule. [Appendix 13] 13. The laminate according to any one of claims 1 to 12, wherein the substrate is a transparent substrate. [Appendix 14] 14. The laminate according to any one of claims 1 to 13, having a surface protection film on at least one surface. [Appendix 15] 15. The laminate according to any one of claims 1 to 14, wherein the hard coat layer is provided on one surface of the substrate, and an adhesive layer is provided on the other surface. [Appendix 16] An image display device comprising the laminate according to any one of appendixes 1 to 15. [Appendix 17] 17. The image display device according to claim 16, which is a foldable display. [Appendix 18] 18. The image display device according to claim 16 or 17, which is an organic electroluminescence display device. [Appendix 19] A foldable device including the image display device according to any one of appendices 16 to 18.

Claims

1. A substrate and a hard coat layer laminated on at least one surface of the substrate, the hard coat layer is a laminate containing no compound corresponding to PFAS, A laminate having a minimum bending radius of 5 mm or less in a cylindrical mandrel test in which the laminate is bent so that the surface of the hard coat layer thereof is convex.

2. 2. The laminate according to claim 1, wherein the hard coat layer can withstand 10,000 or more bending cycles before cracks appear in the hard coat layer in the following flexural durability test. Flexural durability test: From the stretched state, the laminate is bent 180° in the direction in which the hard coat layer surface is convex so that the bending radius is 4.0 mm, and then stretched again. This operation counts as one cycle, and is carried out at a speed of 30 to 60 / min.

3. The hard coat layer is 750 g / cm with #0000 steel wool 2 3. The laminate according to claim 1, wherein the surface of the hard coat layer is rubbed back and forth 1000 times while applying a load of 1000.0 mm.sup.-10 ...

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

5. 3. The laminate according to claim 1, having a haze of 7% or less.

6. The laminate according to claim 1 or 2, wherein the hard coat layer is a cured product of a curable composition containing one or more curable compounds, and the curable compound contains polyorganosilsesquioxane.

7. The laminate according to claim 6 , wherein the curable composition contains a compound having one or more cationically polymerizable groups and one or more radically polymerizable groups in the molecule.

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

9. The laminate according to claim 8 , wherein the curing catalyst comprises a cationic polymerization initiator.

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

11. The laminate according to claim 6 , wherein the curable composition further comprises a radical-curable polyorganosiloxane.

12. The laminate according to claim 6 , wherein the curable composition further comprises an aliphatic compound having two or more cationically polymerizable groups in the molecule.

13. The laminate according to claim 1 or 2, wherein the substrate is a transparent substrate.

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

15. The laminate according to claim 1 or 2, which has the hard coat layer on one surface of the substrate and an adhesive layer on the other surface.

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

17. The image display device according to claim 16, which is a foldable display.

18. 17. The image display device according to claim 16, which is an organic electroluminescence display device.

19. A foldable device comprising the image display device according to claim 16.

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