Curable composition, undercoat layer, laminate and display device

Abstract

To provide a curable composition capable of forming a layer which has excellent adhesion to a base material and a hard coat layer and exhibits high surface hardness when the hard coat layer is laminated.SOLUTION: There is provided a curable composition which comprises a first epoxy compound, which is an organosiloxane containing two or more alicyclic epoxy groups as a curable compound, a second epoxy compound, a polyorganosiloxane having a silanol group and a third epoxy compound or an oxetane compound. Further, the curable composition preferably comprises the first epoxy compound, the second epoxy compound, the polyorganosiloxane having the silanol group and the oxetane compound.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a curable composition, an undercoat layer comprising a cured product of the curable composition, a laminate, and a display device. [Background technology]

[0002] A known configuration is to provide a hard coat layer on the surface of an article (substrate) for which transparency and aesthetics are important, such as a display for a television, a personal computer, a smartphone, or the like, or a film for such a display, in order to improve abrasion resistance (i.e., the ability to prevent damage caused by abrasion or scratching).

[0003] In particular, a configuration in which an undercoat layer (interlayer adhesive layer) is provided between the substrate and the hard coat layer in order to enhance adhesion between the substrate and the hard coat layer is known (for example, Patent Document 1). [Prior art documents] [Non-patent literature]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-55601 Summary of the Invention [Problem to be solved by the invention]

[0005] However, even when an undercoat layer is used, there still remains the problem of insufficient adhesion between the undercoat layer and a hard coat layer of a specific composition.

[0006] Furthermore, increasing the adhesion to the substrate and the hard coat layer tends to result in a decrease in surface hardness when the hard coat layer is laminated, and it has been difficult to achieve both adhesion to the substrate and the hard coat layer and high surface hardness.

[0007] The present disclosure solves the above-mentioned problems, and an object of the present disclosure is to provide a curable composition that has excellent adhesion to a substrate and a hard coat layer and is capable of forming a layer that exhibits high surface hardness when a hard coat layer is laminated thereon. [Means for solving the problem]

[0008] The inventors of the present disclosure have found that a curable composition containing a first epoxy compound, which is an organosiloxane containing two or more alicyclic epoxy groups, a second epoxy compound, a polyorganosiloxane having a silanol group, and a third epoxy compound or an oxetane compound as curable compounds has excellent adhesion to a substrate and a hard coat layer and exhibits high surface hardness when a hard coat layer is laminated thereon. The present disclosure has been completed based on these findings.

[0009] That is, the present disclosure provides a curable composition comprising, as a curable compound, a first epoxy compound which is an organosiloxane containing two or more alicyclic epoxy groups, a second epoxy compound, a polyorganosiloxane having a silanol group, and a third epoxy compound or an oxetane compound.

[0010] The curable composition preferably contains the first epoxy compound, the second epoxy compound, the silanol group-containing polyorganosiloxane, and the oxetane compound.

[0011] In the curable composition, the content of the first epoxy compound is preferably 30 to 70 mass % relative to the total amount of the curable compounds.

[0012] In the curable composition, the content of the second epoxy compound is preferably 20 to 60 mass % relative to the total amount of the curable compounds.

[0013] The curable composition preferably contains the oxetane compound in an amount of 5 to 25% by mass relative to the total amount of the curable compounds.

[0014] In the curable composition, the content of the silanol group-containing polyorganosiloxane is preferably 1 to 15 mass % relative to the total amount of the curable compounds.

[0015] The curable composition preferably does not contain any deleterious substances.

[0016] The curable composition preferably does not contain any compounds that fall under the category of PFAS.

[0017] The present disclosure also provides an undercoat layer comprising a cured product of the curable composition.

[0018] The undercoat layer preferably has a thickness of 0.1 to 20 μm.

[0019] The present disclosure also provides a laminate comprising a substrate, the undercoat layer formed on at least one surface of the substrate, and a hard coat layer laminated in this order.

[0020] In the laminate, the substrate is preferably a glass substrate.

[0021] In the laminate, the hard coat layer preferably contains a curable polyorganosilsesquioxane resin as the curable resin.

[0022] The laminate preferably has a pencil hardness of 3H or more on the surface of the hard coat layer.

[0023] The laminate preferably has 100 squares formed in a grid pattern at 1 mm intervals on the surface of the hard coat layer, and when adhesive tape is applied and peeled off in a 90° direction, 90 or more squares remain.

[0024] In the laminate, the hard coat layer preferably does not contain any compounds that fall under PFAS.

[0025] The present disclosure also provides an image display device including the above laminate. [Effects of the Invention]

[0026] The curable composition of the present disclosure has excellent adhesion to a substrate and a hard coat layer, and can form a layer that exhibits high surface hardness when laminated with a hard coat layer. [Brief explanation of the drawings]

[0027] [Figure 1] FIG. 2 shows the 29Si-NMR spectrum of one embodiment of a polyorganosiloxane having a silanol group. DETAILED DESCRIPTION OF THE INVENTION

[0028] In this disclosure, "(meth)acryloyl group" means an acryloyl group and / or a methacryloyl group. "(meth)acrylate" means an acrylate and / or a methacrylate.

[0029] [Curable composition] The curable composition of the present disclosure contains, as curable compounds, a first epoxy compound which is an organosiloxane containing two or more alicyclic epoxy groups, a second epoxy compound, a polyorganosiloxane having a silanol group, and a third epoxy compound or an oxetane compound.

[0030] The curable composition may be a photocurable composition, a thermosetting composition, or a curable composition having both photocurability and thermosetting properties. Among these, the curable composition is preferably a photocurable composition.

[0031] <Organosiloxane containing two or more alicyclic epoxy groups (first epoxy compound)> The curable composition includes a first epoxy compound, which is an organosiloxane containing two or more alicyclic epoxy groups. The first epoxy compound is a compound having two or more alicyclic epoxy groups in its molecule and further having at least a siloxane skeleton formed by siloxane bonds (Si-O-Si). The siloxane skeleton includes a cyclic siloxane skeleton, a linear or branched silicone (linear or branched polysiloxane), a cage-type or ladder-type polysilsesquioxane, and the like. In the present disclosure, compounds having a cyclic siloxane skeleton are preferred because they can achieve both ease of application to a substrate and good adhesion. Note that the first epoxy compound may be used alone or in combination of two or more types.

[0032] Furthermore, when the first epoxy compound has a cyclic siloxane skeleton, the number of Si—O units forming the siloxane ring (equal to the number of silicon atoms forming the siloxane ring) is preferably 2 to 12, and more preferably 4 to 8.

[0033] The silanol group content in the first epoxy compound is preferably less than 5%, more preferably 1% or less, and even more preferably 0%. That is, the first epoxy compound preferably does not contain silanol groups. The silanol group content can be measured using the same method as that used to measure the polyorganosiloxane having silanol groups described below.

[0034] The number average molecular weight (Mn) of the first epoxy compound, as calculated using standard polystyrene standards by gel permeation chromatography, is not particularly limited, but is preferably from 200 to less than 3,000, more preferably from 300 to 2,000, and even more preferably from 400 to 800.

[0035] The alicyclic epoxy group of the first epoxy compound refers to a cyclic olefin group that has been epoxidized within the molecule. The "epoxidized cyclic olefin group" refers to a group (monovalent group) formed by removing one hydrogen atom from a structure in which at least one carbon-carbon unsaturated bond of a cyclic olefin (a cyclic aliphatic hydrocarbon in which at least one of the carbon-carbon bonds forming the ring is unsaturated) has been epoxidized. In other words, the epoxidized cyclic olefin group is a group that includes an aliphatic hydrocarbon ring structure and an epoxy group, and the epoxy group is an epoxy group composed of two adjacent carbon atoms and an oxygen atom that constitute the aliphatic hydrocarbon ring.

[0036] Examples of the cyclic olefin group (before epoxidation) in the epoxidized cyclic olefin group include cycloalkenyl groups such as a cyclopropenyl group (e.g., a 2-cyclopropen-1-yl group), a cyclobutenyl group (e.g., a 2-cyclobuten-1-yl group), a cyclopentenyl group (e.g., a 2-cyclopenten-1-yl group, a 3-cyclopenten-1-yl group), and a cyclohexenyl group (e.g., a 2-cyclohexen-1-yl group, a 3-cyclohexen-1-yl group); cycloalkadienyl groups such as a 2,4-cyclopentadien-1-yl group, a 2,4-cyclohexadien-1-yl group, and a 2,5-cyclohexadien-1-yl group; and polycyclic groups such as a dicyclopentenyl group, a dicyclohexenyl group, and a norbornenyl group.

[0037] The aliphatic hydrocarbon ring forming the cyclic olefin group in the epoxidized cyclic olefin group may have one or more substituents bonded thereto. Examples of the substituent include substituents having 0 to 20 carbon atoms (more preferably 0 to 10 carbon atoms), and more specifically, halogen atoms such as fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms; hydroxy groups; alkoxy groups such as methoxy groups, ethoxy groups, propoxy groups, isopropyloxy groups, butoxy groups, and isobutyloxy groups (preferably C 1-6 Alkoxy groups, more preferably C 1-4 Alkoxy group; alkenyloxy group such as allyloxy group (preferably C 2-6Alkenyloxy groups, more preferably C 2-4 alkenyloxy group); phenoxy group, tolyloxy group, naphthyloxy group, etc., with C in the aromatic ring 1-4 Alkyl group, C 2-4 Alkenyl group, halogen atom, C 1-4 An aryloxy group (preferably C) which may have a substituent such as an alkoxy group 6-14 aryloxy group; aralkyloxy group such as benzyloxy group, phenethyloxy group (preferably C 7-18 aralkyloxy groups; acyloxy groups such as acetyloxy groups, propionyloxy groups, (meth)acryloyloxy groups, and benzoyloxy groups (preferably C 1-12 acyloxy group; mercapto group; alkylthio group such as methylthio group or ethylthio group (preferably C 1-6 Alkylthio groups, more preferably C 1-4 Alkylthio group; alkenylthio group such as allylthio group (preferably C 2-6 Alkenylthio groups, more preferably C 2-4 alkenylthio group); phenylthio group, tolylthio group, naphthylthio group, etc., with C in the aromatic ring 1-4 Alkyl group, C 2-4 Alkenyl group, halogen atom, C 1-4 An arylthio group (preferably C) which may have a substituent such as an alkoxy group 6-14 arylthio group; aralkylthio group such as benzylthio group, phenethylthio group (preferably C 7-18 aralkylthio groups; carboxy groups; alkoxycarbonyl groups such as methoxycarbonyl groups, ethoxycarbonyl groups, propoxycarbonyl groups, and butoxycarbonyl groups (preferably C 1-6 Alkoxy-carbonyl group; aryloxycarbonyl group such as phenoxycarbonyl group, tolyloxycarbonyl group, naphthyloxycarbonyl group (preferably C 6-14 Aryloxycarbonyl group; aralkyloxycarbonyl group such as benzyloxycarbonyl group (preferably C 7-18aralkyloxy-carbonyl group; amino group; mono- or di-alkylamino group such as methylamino group, ethylamino group, dimethylamino group, diethylamino group (preferably mono- or di-C 1-6 alkylamino group; acylamino group such as acetylamino group, propionylamino group, benzoylamino group (preferably C 1-11 acylamino group; oxetanyl group-containing group such as ethyloxetanyloxy group; acyl group such as acetyl group, propionyl group, benzoyl group; oxo group; two or more of these may be optionally C 1-6 Examples include a group bonded via an alkylene group.

[0038] Among these, the cyclic olefin group is preferably a cyclic olefin group having 5 to 12 carbon atoms, more preferably a cycloalkenyl group having 5 to 12 carbon atoms, and even more preferably a cyclohexenyl group. That is, the epoxidized cyclic olefin group is preferably a group in which a cyclic olefin group having 5 to 12 carbon atoms has been epoxidized, more preferably a group in which a cycloalkenyl group having 5 to 12 carbon atoms has been epoxidized, and even more preferably a group in which a cyclohexenyl group has been epoxidized (cyclohexene oxide group). The first epoxy compound may have one type of epoxidized cyclic olefin group, or may have two or more types.

[0039] The number of epoxidized cyclic olefin groups contained in the molecule of the first epoxy compound is not particularly limited as long as it is two or more, but is preferably 2 to 6, more preferably 3 to 5, and even more preferably 4.

[0040] Examples of the first epoxy compound include 2,4-di[2-(3-{oxabicyclo[4.1.0]heptyl})ethyl]-2,4,6,6,8,8-hexamethyl-cyclotetrasiloxane, 4,8-di[2-(3-{oxabicyclo[4.1.0]heptyl})ethyl]-2,2,4,6,6,8-hexamethyl-cyclotetrasiloxane, 2,4-di[2-(3-{oxabicyclo[4.1.0]heptyl})ethyl]-6,8-dipropyl-2,4,6,8-tetramethyl-cyclotetrasiloxane, and 4,8-di[2-(3-{oxabicyclo[4.1.0]heptyl})ethyl]-2,6-dipropyl propyl-2,4,6,8-tetramethyl-cyclotetrasiloxane, 2,4,8-tri[2-(3-{oxabicyclo[4.1.0]heptyl})ethyl]-2,4,6,6,8-pentamethyl-cyclotetrasiloxane, 2,4,8-tri[2-(3-{oxabicyclo[4.1.0]heptyl})ethyl]-6-propyl-2,4,6,8-tetramethyl-cyclotetrasiloxane, 2,4,6,8-tetra[2-(3-{oxabicyclo[4.1.0]heptyl})ethyl]-2,4,6,8-tetramethyl-cyclotetrasiloxane, and silsesquioxanes having epoxy groups.

[0041] The content of the first epoxy compound in the curable composition of the present disclosure is preferably 30 to 70 mass %, more preferably 35 to 65 mass %, and even more preferably 40 to 60 mass %, relative to the total amount (100 mass %) of the curable compounds. When the content is within the above range, the curable composition can be easily applied to a substrate, and further, the coated substrate has excellent adhesion.

[0042] <Second epoxy compound> The curable composition contains an epoxy compound other than the first epoxy compound and the polyorganosiloxane having a silanol group described below (hereinafter, the other epoxy compound may be referred to as a "second epoxy compound"). By containing the second epoxy compound, the curable composition can be easily applied to a substrate.

[0043] The second epoxy compound may be an alicyclic epoxy compound other than the first epoxy compound, an aliphatic epoxy compound, an aromatic epoxy compound, etc. From the viewpoint of exhibiting ease of application to a substrate in combination with the first epoxy compound, the second epoxy compound is preferably an alicyclic epoxy compound.

[0044] Examples of the other alicyclic epoxy compounds include compounds represented by the following formula (a1).

[0045] [ka]

[0046] In the above formula (a1), R may be the same as the epoxidized cyclic olefin group described above. The two Rs may be the same or different. X represents a single bond or a linking group (a divalent group having one or more atoms; excluding groups containing a siloxane bond). Examples of the linking group include a divalent hydrocarbon group, a carbonyl group, an ether bond, an ester bond, a carbonate group, an amide group, and groups in which multiple groups thereof are linked together. Examples of the divalent hydrocarbon group include a divalent aliphatic hydrocarbon group, a divalent alicyclic hydrocarbon group, and groups in which multiple groups thereof are linked together. Examples of the divalent aliphatic hydrocarbon group include a linear or branched alkylene group (e.g., an alkylene group having 1 to 6 carbon atoms) such as a methylene group, a methylmethylene group, a dimethylmethylene group, an ethylene group, a propylene group, a trimethylene group, or a tetramethylene group. Furthermore, examples of the divalent alicyclic hydrocarbon group include divalent cycloalkylene groups such as 1,2-cyclopentylene, 1,3-cyclopentylene, 1,2-cyclohexylene, 1,3-cyclohexylene, and 1,4-cyclohexylene. Examples of the compound represented by the above formula (a1) include compounds in which both of the two Rs are cyclohexene oxide groups (particularly, compounds in which the carbon atoms at the 4-positions of two cyclohexene oxide groups (the positions of the two carbon atoms forming the epoxy group are considered to be the 1- and 2-positions) are linked by a single bond or a divalent hydrocarbon group).

[0047] Specific examples of the alicyclic epoxy compound represented by the above formula (a1) include (3,4,3',4'-diepoxy)bicyclohexyl, bis(3,4-epoxycyclohexylmethyl)ether, 1,2-epoxy-1,2-bis(3,4-epoxycyclohexane-1-yl)ethane, 2,2-bis(3,4-epoxycyclohexane-1-yl)propane, 1,2-bis(3,4-epoxycyclohexane-1-yl)ethane, bis(3,4-epoxycyclohexylmethyl)ether, and 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate.

[0048] The other alicyclic epoxy compounds also include compounds in which an epoxy group is directly bonded to an alicyclic ring via a single bond, such as a compound represented by the following formula (b1), and hydrogenated aromatic glycidyl ether-based epoxy compounds.

[0049] [ka]

[0050] In formula (b1), R i is a group obtained by removing q -OH from a q-valent alcohol, where p and q each represent a natural number. i Examples of -(OH)q include polyhydric alcohols such as 2,2-bis(hydroxymethyl)-1-butanol (e.g., alcohols having 1 to 15 carbon atoms). q is preferably 1 to 6, and p is preferably 1 to 30. When q is 2 or greater, the p's in the two or more groups in parentheses ( ) may be the same or different. Specific examples of the compound include 1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol, trade name "EHPE3150" (manufactured by Daicel Corporation).

[0051] Examples of the hydrogenated aromatic glycidyl ether epoxy compounds include compounds obtained by hydrogenating bisphenol A epoxy compounds such as 2,2-bis[4-(2,3-epoxypropoxy)cyclohexyl]propane, 2,2-bis[3,5-dimethyl-4-(2,3-epoxypropoxy)cyclohexyl]propane, and polymers thereof (hydrogenated bisphenol A epoxy compounds); bis[o,o-(2,3-epoxypropoxy)cyclohexyl]methane, bis[o,p-(2,3-epoxypropoxy)cyclohexyl]methane, bis[p,p-(2,3-epoxypropoxy)cyclohexyl]methane, bis[o,p-(2,3-epoxypropoxy)cyclohexyl]methane, bis[p,p-(2,3-epoxypropoxy)cyclohexyl]propane, bis[o,o-(2,3-epoxypropoxy)cyclohexyl]methane, bis[o,p-(2,3-epoxypropoxy)cyclohexyl]propane, bis[p,p-(2,3-epoxypropoxy)cyclohexyl]propane, bis[o ... Examples of epoxy compounds include hydrogenated compounds of bisphenol F epoxy compounds such as bis[3,5-dimethyl-4-(2,3-epoxypropoxy)cyclohexyl]methane, bis[3,5-dimethyl-4-(2,3-epoxypropoxy)cyclohexyl]methane, and polymers thereof (hydrogenated bisphenol F epoxy compounds); hydrogenated biphenol epoxy compounds; hydrogenated phenol novolac epoxy compounds; hydrogenated cresol novolac epoxy compounds; hydrogenated cresol novolac epoxy compounds of bisphenol A; hydrogenated naphthalene epoxy compounds; and hydrogenated epoxy compounds of epoxy compounds obtained from trisphenolmethane.

[0052] Examples of the aliphatic epoxy compounds include glycidyl ethers of q-valent alcohols (q is a natural number) that do not have a cyclic structure; glycidyl esters of monovalent or polyvalent carboxylic acids (e.g., acetic acid, propionic acid, butyric acid, stearic acid, adipic acid, sebacic acid, maleic acid, itaconic acid, etc.); epoxidized products of oils and fats having double bonds, such as epoxidized linseed oil, epoxidized soybean oil, and epoxidized castor oil; and epoxidized products of polyolefins (including polyalkadiene), such as epoxidized polybutadiene.

[0053] Examples of the q-valent alcohols not having a cyclic structure include monohydric alcohols such as methanol, ethanol, 1-propyl alcohol, isopropyl alcohol, and 1-butanol; 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 trihydric or higher polyhydric alcohols such as glycerin, diglycerin, erythritol, trimethylolethane, trimethylolpropane, pentaerythritol, dipentaerythritol, and sorbitol. Examples of the q-valent alcohols include polyether polyols, polyester polyols, polycarbonate polyols, and polyolefin polyols.

[0054] Examples of the aromatic epoxy compounds include epibis-type glycidyl ether epoxy resins obtained by a condensation reaction between bisphenols [e.g., bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, etc.] and epihalohydrin; high molecular weight epibis-type glycidyl ether epoxy resins obtained by further addition reaction of these epibis-type glycidyl ether epoxy resins with the above-mentioned bisphenols; phenols [e.g., phenol, cresol, xylenol, resorcinol, catechol, bisphenol A, bisphenol B, etc.]; Examples include novolak alkyl type glycidyl ether epoxy resins obtained by condensing polyhydric alcohols obtained by the condensation reaction of polyphenols (e.g., phenol F, bisphenol S) with aldehydes (e.g., formaldehyde, acetaldehyde, benzaldehyde, hydroxybenzaldehyde, salicylaldehyde) with epihalohydrin; and epoxy compounds in which two phenol skeletons are bonded to the 9-position of the fluorene ring and a glycidyl group is bonded to each of the oxygen atoms obtained by removing the hydrogen atom from the hydroxyl group of these phenol skeletons, either directly or via an alkyleneoxy group.

[0055] The content of the second epoxy compound in the curable composition of the present disclosure is preferably 20 to 60 mass %, more preferably 25 to 55 mass %, and even more preferably 30 to 50 mass %, relative to the total amount (100 mass %) of the curable compounds. When the content is within the above range, the curable composition can be easily applied to a substrate.

[0056] <Silanol-containing polyorganosiloxane> The curable composition contains a polyorganosiloxane having silanol groups in addition to the first epoxy compound and the second epoxy compound. It is presumed that the silanol groups contained in the polyorganosiloxane having silanol groups interact with the substrate and the hard coat layer to improve adhesion. In addition, the polyorganosiloxane having silanol groups is preferably a compound that differs from the first epoxy compound in terms of the silanol group abundance rate or number average molecular weight, and more preferably a compound that differs in silanol group abundance rate and number average molecular weight. Only one type of polyorganosiloxane having silanol groups may be used, or two or more types may be used.

[0057] The number average molecular weight (Mn) of the silanol group-containing polyorganosiloxane, as calculated using standard polystyrene standards by gel permeation chromatography, is not particularly limited, but is preferably, for example, 1,000 to 20,000, more preferably 1,500 to 15,000, and even more preferably 2,000 to 10,000.

[0058] The structural units contained in the polyorganosiloxane having a silanol group include [RSiO 1 / 2 ], the structural unit (M unit) represented by [R2SiO 2 / 2 ], the structural unit (D unit) represented by [RSiO 3 / 2 ] and the structural unit (T unit) represented by [SiO 4 / 2 Among these, those containing the T unit are preferred.

[0059] The proportion (total amount) of the T units relative to the total amount of siloxane constituent units in the silanol group-containing polyorganosiloxane [total siloxane constituent units; total amount of M units, D units, T units, and Q units] (100 mol%) is not particularly limited, but is preferably 70 mol% or more, more preferably 80 mol% or more, and even more preferably 90 mol% or more. By setting the proportion to 70 mol% or more, it is possible to easily improve the adhesion of the curable composition. The upper limit is not particularly limited, but may be 100 mol%. The proportion of each siloxane constituent unit in the polyorganosilsesquioxane of the present disclosure can be calculated, for example, from the composition of the raw materials or the NMR spectrum measurement described below.

[0060] The proportion of silanol groups contained in the silanol group-containing polyorganosiloxane is preferably 5% or more, more preferably 10% or more, even more preferably 15% or more, and particularly preferably 20% or more. By having a proportion of silanol groups of 5% or more, it becomes easier to exhibit adhesion to the substrate, and the upper limit is not particularly limited, but may be 50% or less.

[0061] The silanol group abundance can be measured by the following method. FIG. 1 shows an embodiment of a polyorganosiloxane having silanol groups. 29This figure shows a spectrum obtained by Si-NMR measurement. The obtained spectrum was subjected to waveform separation, and the peak observed between -47 ppm and -53 ppm in chemical shift was identified as originating from the T1 isomer structure, the peak observed between -54 ppm and -60 ppm as originating from the T2 isomer structure, and the peak observed between -64 ppm and -70 ppm as originating from the T3 isomer structure. The T1, T2, and T3 isomers are defined based on the number of silicon atoms bonded via oxygen atoms. The ratio (%) of the peak area value of each of the T1 to T3 isomers to the total area value (100%) of each peak represents the content (mol%) of each structure (T1 to T3 isomers) in the silanol-containing polyorganosiloxane being measured. Using this value and the ratio of hydroxyl groups to the total number of moles of oxygen atoms and hydroxyl groups in each of the T1 to T3 isomers, the abundance (%) of all silanol groups can be calculated according to the following formula: Silanol group abundance (%) = (T1 × 2 / 3 + T2 × 1 / 3 + T3 × 0 / 3) In the above formula, T1, T2 and T3 are respectively 29 This shows the ratio (%) of the peak area attributable to each silicon atom structure to the total peak area (100%) attributable to the silicon atom structure obtained by Si-NMR measurement, i.e., the content ratio of each structure obtained from the above NMR measurement results.

[0062] Similarly, for D units, 29 The spectrum obtained by Si-NMR measurement is subjected to waveform separation and identified as originating from the D1 structure or the D2 structure. The D1 and D2 structures are defined based on the number of silicon atoms bonded via oxygen atoms. In addition, the abundance rate (%) of all silanol groups can be calculated using the same method as for the T unit above according to the following formula. Silanol group abundance (%) = (D1 × 1 / 2 + D2 × 0 / 2)

[0063] Similarly, for Q units, 29The spectrum obtained by Si-NMR measurement is subjected to waveform separation and identified as originating from the Q1, Q2, Q3, or Q4 structure. The Q1, Q2, Q3, and Q4 structures are defined based on the number of silicon atoms bonded via oxygen atoms. The abundance ratio (%) of all silanol groups can be calculated using the same method as for the T unit above according to the following formula: Silanol group abundance (%) = (Q1 x 3 / 4 + Q2 x 2 / 4 + Q3 x 1 / 4 + Q4 x 0 / 4)

[0064] The abundance of silanol groups contained in the above-mentioned T units, D units, and Q units can be measured and added together to calculate the abundance ratio of silanol groups contained in the above-mentioned silanol group-containing polyorganosiloxane.

[0065] The polyorganosiloxane having the silanol group 29 The Si-NMR spectrum can be measured, for example, using the following apparatus and conditions. Measuring device: Product name “JNM-ECA500NMR” (manufactured by JEOL Ltd.) Solvent: deuterated chloroform Accumulation count: 10,000 times Measurement temperature: 25℃

[0066] Furthermore, when the silanol group-containing polyorganosiloxane contains T units, the content of the T1 isomer is preferably 5% or more, more preferably 10% or more, relative to the total of the T1 to T3 isomers (100%). By ensuring that the content of the T1 isomer is 5% or more, it is possible to ensure a sufficient proportion of silanol groups. The upper limit is not particularly limited, but may be 50% or less, or may be 30% or less.

[0067] Furthermore, when the silanol group-containing polyorganosiloxane contains T units, the content of the T2 isomer is preferably 30% or more, more preferably 40% or more, and even more preferably 50% or more, relative to the total of the T1 to T3 isomers (100%). By ensuring that the T2 isomer content is 30% or more, it is possible to ensure a sufficient proportion of silanol groups. The upper limit is not particularly limited, but may be 80% or less, or may be 70% or less.

[0068] Furthermore, when the silanol-containing polyorganosiloxane contains T units, the content of the T3 isomer is preferably 40% or less, more preferably 30% or less, relative to the total of the T1 to T3 isomers (100%). The lower limit is not particularly limited, but may be 5% or more, or may be 10% or more.

[0069] The polyorganosiloxane having the silanol group preferably contains an active energy ray-curable functional group. Examples of the active energy ray-curable functional group include a photocationically polymerizable functional group and a photoradically polymerizable functional group. Among these, the photocationically polymerizable functional group preferably contains an epoxy group. Examples of the epoxy group include the same groups as those exemplified as the epoxy groups contained in the first epoxy compound and the second epoxy compound, and particularly preferably contain a glycidyl ether group or a group exemplified as an aromatic epoxy compound.

[0070] The content of the polyorganosiloxane having silanol groups is preferably 1 to 15% by mass, more preferably 2 to 10% by mass, relative to the total amount (100% by mass) of the curable compound. When the content of the polyorganosiloxane having silanol groups is 1% by mass or more, the amount of silanol groups is sufficient, making it easier to exhibit adhesion. Furthermore, when the content is 15% by mass or less, excellent storage stability is achieved.

[0071] <Oxetane compounds> In one embodiment of the curable composition of the present disclosure, an oxetane compound is contained in addition to the first epoxy compound, the second epoxy compound, and the polyorganosiloxane having a silanol group. The oxetane compound is a compound having at least one oxetanyl group as a cationically polymerizable group in one molecule, and may be a compound having two or more oxetanyl groups. One or more of the oxetane compounds can be used. By containing the oxetane compound, the curable composition tends to exhibit better adhesion to the substrate.

[0072] Examples of the oxetane compound include trimethylene oxide, 3,3-bis(vinyloxymethyl)oxetane, 3-ethyl-3-hydroxymethyloxetane, 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane, 3-ethyl-3-(hydroxymethyl)oxetane, 3-ethyl-3-[(phenoxy)methyl]oxetane, 3-ethyl-3-(hexyloxymethyl)oxetane, 3-ethyl-3-(chloromethyl)oxetane, and 3,3-bis (chloromethyl)oxetane, 1,4-bis[(3-ethyl-3-oxetanylmethoxy)methyl]benzene, bis{[1-ethyl(3-oxetanyl)]methyl}ether, 4,4'-bis[(3-ethyl-3-oxetanyl)methoxymethyl]bicyclohexyl, 1,4-bis[(3-ethyl-3-oxetanyl)methoxymethyl]cyclohexane, 3-ethyl-ethyl(3-ethyloxetan-3-yl)methoxy]methyl}oxetane, and the like can be mentioned.

[0073] The content of the oxetane compound is preferably 5 to 25 mass %, more preferably 10 to 20 mass %, relative to the total amount (100 mass %) of the curable compound. When the content of the oxetane compound is within the above range, adhesion to the substrate is easily exhibited.

[0074] The curable composition may contain a third epoxy compound and a fourth epoxy compound, which will be described later, together with the oxetane compound.

[0075] <Third Epoxy Compound> In another embodiment of the curable composition of the present disclosure, in addition to the first epoxy compound, the second epoxy compound, and the polyorganosiloxane having a silanol group, it is preferable to contain a third epoxy compound that is not included in the first epoxy compound and the polyorganosiloxane having a silanol group and is a component different from the second epoxy compound. In the curable composition, the epoxy compound with a higher content is referred to as the second epoxy compound, and the epoxy compound with a lower content is referred to as the third epoxy compound.

[0076] The third epoxy compound may be any epoxy compound other than those used as the second epoxy compound, which does not fall under the category of the first epoxy compound or the polyorganosiloxane having a silanol group. Specifically, the second epoxy compound may be any of those exemplified above.

[0077] As the third epoxy compound, it is preferable to contain an aliphatic epoxy compound as the third epoxy compound, particularly when the second epoxy compound contains an alicyclic epoxy compound. By containing the aliphatic epoxy compound as the third epoxy compound, it becomes easier to exhibit adhesion to the substrate. Note that, as the aliphatic epoxy compound, those exemplified as the aliphatic epoxy compound for the second epoxy compound can be used.

[0078] When the third epoxy compound is contained, the content of the third epoxy compound is preferably 5 to 25 mass % and more preferably 7 to 20 mass % relative to the total amount (100 mass %) of the curable compound. When the content of the third epoxy compound is within the above range, adhesion to the substrate is easily exhibited.

[0079] The curable composition may further contain an epoxy compound other than the first to third epoxy compounds and the silanol-containing polyorganosiloxane (hereinafter referred to as a "fourth epoxy compound"). As the fourth epoxy compound, any epoxy compound other than those used as the second and third epoxy compounds can be used, among the epoxy compounds not corresponding to the first epoxy compound. That is, any epoxy compound exemplified as the second epoxy compound other than those used as the second and third epoxy compounds can be used as the fourth epoxy compound. In the curable composition, the fourth epoxy compound is an epoxy compound contained in a smaller amount than the second epoxy compound and the third epoxy compound. One or more types of the fourth epoxy compound can be used.

[0080] Furthermore, when the curable composition is a thermosetting composition, it may further contain a thermosetting resin. Examples of the thermosetting resin include phenolic resin, melamine resin, urea resin, silicone resin, epoxy resin, unsaturated polyester, vinyl ester resin, polyurethane, etc. The thermosetting resin may be used alone or in combination of two or more.

[0081] The curable composition preferably further contains a curing agent. As the curing agent, a known or commonly used thermal polymerization initiator or photopolymerization initiator can be used, and a photopolymerization initiator is preferably used. Among these, a photocationic polymerization initiator is preferably used as the photopolymerization initiator. The curing agent can be used alone or in combination of two or more.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] The anion constituting the above salt is, for example, PF6 - , BF4 - , (C6F5)4B - , (C6F5)4Ga - , sulfonate anion, perhalogenate ion, halogenated sulfonate ion, sulfate ion, carbonate ion, aluminate ion, carboxylate ion, arylborate ion, thiocyanate ion, nitrate ion, and the like.

[0091] The amount of the curing agent used (blended amount) is preferably 0.01 to 15 parts by mass, more preferably 0.03 to 10 parts by mass, even more preferably 0.05 to 10 parts by mass, and particularly preferably 0.1 to 5 parts by mass, relative to the total amount (100 parts by mass) of the curable compounds contained in the curable composition. By using the curing agent within the above range, a cured product having excellent adhesion to the substrate can be obtained.

[0092] The curable composition preferably further contains an antioxidant. Known or commonly used antioxidants can be used as the antioxidant. One or more of the antioxidants can be used.

[0093] As the antioxidant, known or commonly used antioxidants can be used, and examples thereof include, but are not limited to, phenol-based antioxidants (phenol-based compounds), hindered amine-based antioxidants (hindered amine-based compounds), phosphorus-based antioxidants (phosphorus-based compounds), and sulfur-based antioxidants (sulfur-based compounds).

[0094] 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.

[0095] 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.

[0096] 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.

[0097] Examples of the sulfur-based antioxidant include dodecanethiol, dilauryl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, and distearyl-3,3'-thiodipropionate.

[0098] Among these, phenol-based antioxidants, phosphorus-based antioxidants, and sulfur-based antioxidants are preferred, and phenol-based antioxidants are particularly preferred.

[0099] The amount of the antioxidant used (blended amount) is preferably 0.01 to 15 parts by mass, more preferably 0.03 to 10 parts by mass, even more preferably 0.05 to 10 parts by mass, and particularly preferably 0.1 to 5 parts by mass, relative to the total amount (100 parts by mass) of the curable compound.

[0100] <Other compounds> The curable composition of the present disclosure may contain other compounds in addition to the above compounds. Examples of the other compounds include solvents, metal oxide particles, rubber particles, silicone antifoaming agents, silane coupling agents, fillers, plasticizers, antistatic agents, flame retardants, colorants, UV absorbers, ion adsorbents, pigments, and release agents. The content (blending amount) of these various additives is preferably 5% by mass or less of the total amount (100% by mass) of the curable composition.

[0101] In addition, the curable composition preferably does not contain compounds that fall under PFAS. By having the above-mentioned configuration, compounds that fall under PFAS are not used, which makes it possible to comply with environmental regulations and achieve excellent safety. In this disclosure, "compounds that fall under PFAS" is a general term for perfluoroalkyl compounds and polyfluoroalkyl compounds.

[0102] The content of deleterious substances in the curable composition is preferably 1000 ppm by mass or less, more preferably 0 ppm by mass, relative to the total amount (100% by mass) of the curable composition. That is, the curable composition is preferably free of deleterious substances. Specific examples of the deleterious substances include antimony compounds.

[0103] [Undercoat layer]

[0013] An embodiment of the present disclosure includes an undercoat layer containing a cured product of the curable composition. The undercoat layer can be obtained, for example, by applying the curable composition to at least one surface of a substrate and curing the composition.

[0104] The substrate may be a single layer or multiple layers made of the same or different materials. The substrate may be a resin substrate, a glass substrate, a metal substrate, or the like, and is preferably a glass substrate from the viewpoint of adhesion to the undercoat layer.

[0105] The undercoat layer can be formed by a conventional coating method. For example, well-known methods such as dipping, roll coating, gravure coating, reverse coating, air knife coating, comma coating, die coating, screen printing, spray coating, inkjet coating, spin coating, gravure offset, and organic vapor deposition can be used. When the curable composition is a photocurable composition, examples of the curing treatment include 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. The cumulative irradiation dose is, for example, 300 to 10,000 mJ / cm. 2 It is preferable to irradiate in a range such that the curable composition is a thermosetting composition. When the curable composition is a thermosetting composition, the curing may be performed under conditions of a heating temperature of 50 to 200°C and a heating time of 5 to 120 minutes. The heating temperature may be constant or may be changed stepwise. Alternatively, a film previously coated on another substrate by the above-mentioned forming method may be transferred to the substrate using a transfer method such as adhesive transfer, thermal transfer, or UV transfer.

[0106] When the curable composition is a photocurable composition, it is preferable to further perform an annealing treatment after the completion of light irradiation to remove internal strain, for example, by heating at a temperature of 100 to 200° C. for about 30 minutes to 1 hour.

[0107] Furthermore, when the appearance of the undercoat layer is visually inspected after curing, it is preferable that the undercoat layer can be applied to the substrate without repellency, and it is more preferable that the undercoat layer surface is not rough and can be applied uniformly.

[0108] The thickness of the undercoat layer is preferably 0.1 to 20 μm, more preferably 1 to 15 μm. When the thickness of the undercoat layer is 0.1 μm or more, adhesion between the substrate and the hard coat layer can be easily exhibited. Furthermore, when the thickness is 20 μm or less, it is easy to improve the surface hardness of the hard coat layer surface when the hard coat layer is laminated.

[0109] [Laminate] One embodiment of the present disclosure is a laminate including the substrate, the undercoat layer, and a hard coat layer. The laminate can be produced by further forming a hard coat layer on the undercoat layer formed on the substrate. In the laminate, the laminate structure may be formed on only one surface (one side) of the substrate, or on both surfaces (both sides). The laminate may also have layers other than the undercoat layer and the hard coat layer. From the viewpoint of exhibiting adhesion of the laminate, it is preferable that the substrate, undercoat layer, and hard coat layer are laminated in this order.

[0110] The hard coat layer preferably contains a curable resin, and the curable resin preferably contains a curable polyorganosilsesquioxane resin that is a cured product of a polyorganosilsesquioxane having a structural unit represented by the following formula (1) (hereinafter, sometimes referred to as the "polyorganosilsesquioxane of the present disclosure"). In other words, the curable composition for forming the hard coat layer (hereinafter, sometimes referred to as the "hard coat agent") preferably contains a polyorganosilsesquioxane having a structural unit represented by the following formula (1). As described below, the hard coat agent may contain other components such as a curing agent (particularly a photocationic polymerization initiator or a photoradical polymerization initiator), an antioxidant, etc. [ka] [In formula (1), R 1 represents a group containing an active energy ray-curable functional group.]

[0111] The polyorganosilsesquioxane of the present disclosure is characterized by having a structural unit represented by the above formula (1). The polyorganosilsesquioxane of the present disclosure preferably has a structural unit represented by the following formula (I) (sometimes referred to as a "T3 form") and a structural unit represented by the following formula (II) (sometimes referred to as a "T2 form"). Furthermore, the polyorganosilsesquioxane of the present disclosure preferably has a structural unit represented by the below-described formula (4). [ka] [ka]

[0112] The structural unit represented by the above formula (1) is generally [RSiO 3 / 2 The structural unit represented by formula (1) is a silsesquioxane structural unit (T unit) represented by the formula (1). In the above formula, R represents a hydrogen atom or a monovalent organic group, and this also applies hereinafter. The structural unit represented by formula (1) is formed by hydrolysis and condensation reaction of a corresponding hydrolyzable trifunctional silane compound (specifically, for example, a compound represented by formula (a) described below).

[0113] R in formula (1) 1 represents a group (monovalent group) containing an active energy ray-curable functional group. That is, the polyorganosilsesquioxane of the present disclosure is a photocationically curable compound (photocationically polymerizable compound) or a photoradical curable compound (photoradical polymerizable compound) having at least an active energy ray-curable functional group in the molecule.

[0114] The "photocationically polymerizable functional group" in the group containing the active energy ray-curable functional group is not particularly limited as long as it has photocationic polymerizability, and examples thereof include an epoxy group, an oxetane group, a vinyl ether group, and a vinylphenyl group. The "photoradical polymerizable functional group" in the group containing the active energy ray-curable functional group is not particularly limited as long as it has photoradical polymerizability, and examples thereof include a (meth)acryloxy group, a (meth)acrylamide group, a vinyl group, and a vinylthio group. From the viewpoint of the surface hardness of the cured product (coating film), the active energy ray-curable functional group is preferably an epoxy group or a (meth)acryloxy group, and particularly preferably an epoxy group.

[0115] 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 hard coating agent and the scratch resistance and toughness of the cured product (coating film), 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]

[0116] In the above formula (1a), R 1arepresents a linear or branched alkylene group. Examples of the linear or branched alkylene group include linear or branched alkylene groups having 1 to 10 carbon atoms, such as methylene, methylmethylene, dimethylmethylene, ethylene, propylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, and decamethylene. Among these, R 1a From the viewpoint of the scratch resistance and toughness of the cured product (coating film), 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.

[0117] 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 scratch resistance and toughness of the cured product (coating film), 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.

[0118] In the above formula (1c), R 1c represents a linear or branched alkylene group, and R 1a Among them, R 1c From the viewpoint of the scratch resistance and toughness of the cured product (coating film), 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.

[0119] In the above formula (1d), R 1d represents a linear or branched alkylene group, and R 1a Among them, R 1dFrom the viewpoint of the scratch resistance and toughness of the cured product (coating film), 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.

[0120] R in formula (1) 1 From the viewpoint of the scratch resistance and toughness of the cured product (coating film), the group represented by the above formula (1a), R 1a is an ethylene group [particularly, a 2-(3',4'-epoxycyclohexyl)ethyl group] is preferred.

[0121] Examples of the oxetane group-containing group include known or commonly used groups having an oxetane ring, and are not particularly limited. Examples include the oxetane group itself and groups in which a hydrogen atom (usually one or more, preferably one hydrogen atom) of an alkyl group (preferably an alkyl group having 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms) is substituted with an oxetane group. From the viewpoints of the curability of the hard coating agent and the scratch resistance and toughness of the cured product (coating film), preferred are a 3-oxetanyl group, an oxetan-3-ylmethyl group, a 3-ethyloxetan-3-ylmethyl group, a 2-(oxetan-3-yl)ethyl group, a 2-(3-ethyloxetan-3-yl)ethyl group, a 3-(oxetan-3-ylmethoxy)propyl group, a 3-(3-ethyloxetan-3-ylmethoxy)propyl group, and the like.

[0122] Examples of the vinyl ether group-containing group include known or commonly used groups having a vinyl ether group, and are not particularly limited, but include, for example, the vinyl ether group itself and a group in which a hydrogen atom (usually one or more, preferably one hydrogen atom) of an alkyl group (preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms) is substituted with a vinyl ether group. From the viewpoints of the curability of the hard coating agent and the scratch resistance and toughness of the cured product (coating film), a vinyloxymethyl group, a 2-(vinyloxy)ethyl group, a 3-(vinyloxy)propyl group, etc. are preferred.

[0123] Examples of the vinylphenyl group-containing group include known or commonly used groups having a vinylphenyl group, and are not particularly limited, but include, for example, the vinylphenyl group itself and groups in which a hydrogen atom (usually one or more, preferably one hydrogen atom) of an alkyl group (preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms) is substituted with a vinylphenyl group. From the viewpoints of the curability of the hard coating agent and the scratch resistance and toughness of the cured product (coating film), 4-vinylphenyl, 3-vinylphenyl, 2-vinylphenyl, etc. are preferred.

[0124] The (meth)acryloxy group-containing group includes, but is not limited to, known or commonly used groups having a (meth)acryloxy group, and examples thereof include the (meth)acryloxy group itself and groups in which a hydrogen atom (usually one or more, preferably one hydrogen atom) of an alkyl group (preferably an alkyl group having 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms) is substituted with a (meth)acryloxy group. From the viewpoints of the curability of the hard coating agent (coating film) and the scratch resistance and toughness of the cured product (coating film), a 2-((meth)acryloxy)ethyl group, a 3-((meth)acryloxy)propyl group, etc. are preferred.

[0125] The group containing the (meth)acrylamide group includes, but is not limited to, known or commonly used groups having a (meth)acrylamide group, and examples thereof include the (meth)acrylamide group itself and groups in which a hydrogen atom (usually one or more, preferably one hydrogen atom) of an alkyl group (preferably an alkyl group having 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms) is substituted with a (meth)acrylamide group. From the viewpoints of the curability of the hard coating agent and the scratch resistance and toughness of the cured product (coating film), a 2-((meth)acrylamide)ethyl group, a 3-((meth)acrylamide)propyl group, etc. are preferred.

[0126] Examples of the vinyl group-containing group include known or commonly used groups having a vinyl group, and are not particularly limited, but include, for example, the vinyl group itself and groups in which a hydrogen atom (usually one or more, preferably one hydrogen atom) of an alkyl group (preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms) is substituted with a vinyl group. From the viewpoints of the curability of the hard coating agent and the scratch resistance and toughness of the cured product (coating film), vinyl groups, vinylmethyl groups, 2-vinylethyl groups, 3-vinylpropyl groups, etc. are preferred.

[0127] The vinylthio group-containing group includes, but is not limited to, known or commonly used groups having a vinylthio group, and examples thereof include the vinylthio group itself and groups in which a hydrogen atom (usually one or more, preferably one hydrogen atom) of an alkyl group (preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms) is substituted with a vinylthio group. From the viewpoints of the curability of the hard coating agent and the scratch resistance and toughness of the cured product (coating film), a vinylthiomethyl group, a 2-(vinylthio)ethyl group, a 3-(vinylthio)propyl group, etc. are preferred.

[0128] R in formula (1) 1 From the viewpoint of the scratch resistance and toughness of the cured product (coating film), groups containing an epoxy group and groups containing a (meth)acryloxy group are preferred, and in particular, groups represented by the above formula (1a), R 1a is an ethylene group [among which, a 2-(3',4'-epoxycyclohexyl)ethyl group, a 3-(acryloxy)propyl group, and a 3-(methacryloxy)propyl group are preferred].

[0129] The polyorganosilsesquioxane of the present disclosure 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).

[0130] The polyorganosilsesquioxanes of the present disclosure comprise silsesquioxane building blocks [RSiO 3 / 2In 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). [ka]

[0131] The structural unit represented by the above formula (2) is generally [RSiO 3 / 2 In other words, the constitutional unit represented by the above formula (2) is formed by the hydrolysis and condensation reaction of the corresponding hydrolyzable trifunctional silane compound (specifically, for example, a compound represented by the formula (b) described below).

[0132] 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, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted alkenyl 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 linear or branched 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. Examples of the alkenyl group include a linear or branched alkenyl group such as a vinyl group, an allyl group, and an isopropenyl group.

[0133] Examples of the above-mentioned substituted aryl group, substituted aralkyl group, substituted cycloalkyl group, substituted alkyl group, and substituted alkenyl 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, alkyl group, and alkenyl group are substituted with at least one selected from the group consisting of an ether group, an ester group, a carbonyl group, a siloxane group, a halogen atom (such as a fluorine atom), an acrylic group, a methacrylic group, a mercapto group, an amino group, and a hydroxyl group.

[0134] Among them, R 2 As the alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted alkenyl group is preferred, a substituted or unsubstituted aryl group is more preferred, and a phenyl group is even more preferred.

[0135] The proportion of each of the above-mentioned silsesquioxane constituent units (constituent units represented by formula (1) and constituent units represented by formula (2)) in the polyorganosilsesquioxane of the present disclosure can be appropriately adjusted by the composition of the raw materials (hydrolyzable trifunctional silanes) used to form these constituent units.

[0136] The polyorganosilsesquioxane of the present disclosure further comprises a silsesquioxane structural unit [RSiO ] other than the structural unit represented by the above formula (1) and the structural unit represented by the formula (2). 3 / 2 ], and may have at least one siloxane structural unit selected from the group consisting of M units, D units, and Q units. Examples of silsesquioxane structural units other than the structural units represented by the above formula (1) and the structural units represented by the formula (2) include structural units represented by the following formula (3). [ka]

[0137] When the polyorganosilsesquioxane of the present disclosure has a structural unit (T3 isomer) represented by formula (I) above and a structural unit (T2 isomer) represented by formula (II) above, the ratio [T3 isomer / T2 isomer] is not particularly limited and can be appropriately selected, for example, from the range of 5 or more (e.g., 5 or more and 500 or less). The lower limit of the ratio [T3 isomer / T2 isomer] is preferably 20, more preferably 21, more preferably 23, and even more preferably 25. By setting the ratio [T3 isomer / T2 isomer] to 5 or more, the surface hardness, scratch resistance, and toughness of the cured product (coating film) tend to be improved. On the other hand, the upper limit of the ratio [T3 isomer / T2 isomer] is preferably 500, more preferably 100, more preferably 50, and even more preferably 40. By setting the ratio [T3 isomer / T2 isomer] to 500 or less, compatibility with other components in the hard coating agent is improved and viscosity is suppressed, making the agent easier to handle and easier to apply as a hard coating agent.

[0138] 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]

[0139] R in the above formula (I) a (R in formula (I') aThe same applies to R in formula (II). b (R in formula (II') b and (the same applies to R and R) each represent a group containing an active energy ray-curable 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, a substituted or unsubstituted alkenyl 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 and R in the formulas (a) to (c) described below respectively represent groups bonded to silicon atoms in the hydrolyzable trifunctional silane compounds used as raw materials for the polyorganosilsesquioxanes of the present disclosure (groups other than alkoxy groups and halogen atoms). 1 , R 2 , hydrogen atoms, etc.

[0140] 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. c The alkyl group in the formula (I) is generally an alkoxy group (for example, an alkoxy group in the hydrolyzable silane compound used as a raw material for the polyorganosilsesquioxane of the present disclosure) (for example, an alkoxy group in the formula (I) described later). 1 ~X 3 It is derived from an alkyl group that forms an alkoxy group or the like.

[0141] The ratio [T3 isomer / T2 isomer] in the polyorganosilsesquioxane of the present disclosure may be, for example, 29 It can be determined by Si-NMR spectroscopy. 29In the Si-NMR spectrum, the silicon atom in the constitutional unit (T3 isomer) represented by the above formula (I) and the silicon atom in the constitutional unit (T2 isomer) represented by the above formula (II) show signals (peaks) at different positions (chemical shifts), and the ratio [T3 isomer / T2 isomer] can be determined by calculating the integral ratio of these respective peaks. Specifically, for example, the polyorganosilsesquioxane of the present disclosure is represented by the above formula (1), R 1 When R has a structural unit in which R 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 -62 to -72 ppm, and the signal of the silicon atom in the structure represented by formula (II) (T2 isomer) appears at -55 to -60 ppm. Therefore, in this case, the ratio [T3 isomer / T2 isomer] can be determined by calculating the integral ratio of the signal from -62 to -72 ppm (T3 isomer) to the signal from -55 to -60 ppm (T2 isomer). 1 When the T3 is a group containing an active energy ray-curable functional group other than a 2-(3',4'-epoxycyclohexyl)ethyl group, the ratio [T3 isomer / T2 isomer] can be calculated in the same manner. 29 The Si-NMR spectrum can be measured under the same conditions as those for the measurement of the polyorganosiloxane having silanol groups.

[0142] When the ratio [T3 isomer / T2 isomer] of the polyorganosilsesquioxane of the present disclosure is within the above range (for example, 5 or more and 500 or less), this means that a certain amount of T2 isomer is present relative to the T3 isomer in the polyorganosilsesquioxane of the present disclosure. Examples of such T2 isomers include a constitutional unit represented by the following formula (4), a constitutional unit represented by the following formula (5), and a constitutional 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. [ka] [ka] [ka]

[0143] The polyorganosilsesquioxane of the present disclosure may have any of a cage type, an incomplete cage type, a ladder type, and a random type silsesquioxane structure, or may have a combination of two or more of these silsesquioxane structures.

[0144] When the polyorganosilsesquioxane of the present disclosure has a structural unit represented by the above formula (4), the proportion (total amount) of the structural unit represented by the above formula (1) and the structural unit represented by the above formula (4) relative to the total amount of siloxane structural units [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 55 to 100 mol%, more preferably 65 to 100 mol%, and even more preferably 80 to 99 mol%. By setting the proportion to 55 mol% or more, the curability of the hard coating agent is improved, and the scratch resistance and toughness of the cured product (coating film) are significantly improved. The proportion of each siloxane structural unit in the polyorganosilsesquioxane of the present disclosure can be calculated, for example, from the composition of the raw materials or NMR spectroscopy.

[0145] 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 [total siloxane structural units; total amount of M units, D units, T units, and Q units] (100 mol%) in the polyorganosilsesquioxane of the present disclosure is not particularly limited, but is preferably 0 to 70 mol%, more preferably 0 to 60 mol%, even more preferably 0 to 40 mol%, and particularly preferably 1 to 15 mol%. By setting the above proportion to 70 mol% or less, the proportions of the structural units represented by formula (1) and the structural units represented by formula (4) can be relatively increased, which improves the curability of the hard coating agent and tends to further increase the scratch resistance and toughness of the cured product (coating film).

[0146] The proportion (total amount) of the structural units represented by the formula (1), the structural units represented by the formula (2), the structural units represented by the formula (4), and the structural units represented by the formula (5) relative to the total amount of siloxane structural units [total siloxane structural units; total amount of M units, D units, T units, and Q units] (100 mol%) in the polyorganosilsesquioxane of the present disclosure is not particularly limited, but is preferably 60 to 100 mol%, more preferably 70 to 100 mol%, and even more preferably 80 to 100 mol%. By setting the proportion to 60 mol% or more, the scratch resistance and toughness of the cured product (coating film) tend to be higher.

[0147] The number average molecular weight (Mn) of the polyorganosilsesquioxane of the present disclosure, as measured by gel permeation chromatography in terms of standard polystyrene, is not particularly limited, but can be appropriately selected, for example, from the range of 1,000 to 50,000. The lower limit of the number average molecular weight is preferably 1,500, more preferably 1,800, and even more preferably 2,000. By adjusting the number average molecular weight to 1,000 or more, the scratch resistance and toughness of the cured product (coating film) tend to be further improved. On the other hand, the upper limit of the number average molecular weight is preferably 50,000, more preferably 10,000, and even more preferably 8,000. By adjusting the number average molecular weight to 50,000 or less (e.g., 3,000 or less), compatibility with other components in the hard coating agent is improved, and the scratch resistance and toughness of the cured product (coating film) tend to be further improved.

[0148] The molecular weight dispersity (Mw / Mn) of the polyorganosilsesquioxane of the present disclosure, as measured by gel permeation chromatography in terms of standard polystyrene, is not particularly limited, and can be appropriately selected from the range of 1.0 to 4.0. The lower limit of the molecular weight dispersity is preferably 1.0, more preferably 1.1, and even more preferably 1.2. By adjusting the molecular weight dispersity to 1.1 or more, the hard coating agent tends to be more easily liquid, and handleability tends to be improved. On the other hand, the upper limit of the molecular weight dispersity is preferably 4.0, more preferably 3.0, and even more preferably 2.5. By adjusting the molecular weight dispersity to 4.0 or less, the scratch resistance and toughness of the cured product (coating film) tend to be improved.

[0149] The number average molecular weight and molecular weight dispersity of the polyorganosilsesquioxane of the present disclosure 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) 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

[0150] The 5% weight loss temperature (T d5 Although not particularly limited, the 5% weight loss temperature is preferably 330°C or higher (e.g., 330 to 450°C), more preferably 340°C or higher, and even more preferably 350°C or higher. A 5% weight loss temperature of 330°C or higher tends to further improve the scratch resistance and toughness of the cured product (coating film). In particular, when the polyorganosilsesquioxane of the present disclosure has the above-mentioned ratio [T3 isomer / T2 isomer] of 5 to 500, a number average molecular weight of 1,000 to 50,000, and a molecular weight dispersity of 1.0 to 4.0, the 5% weight loss temperature is controlled to 330°C or higher. The 5% weight loss temperature is the temperature at which a 5% weight loss occurs when heated at a constant heating rate, and serves as an index of heat resistance. The 5% weight loss temperature can be measured by TGA (thermogravimetric analysis) in an air atmosphere at a heating rate of 5°C / min.

[0151] Furthermore, the proportion of silanol groups in the polyorganosilsesquioxane of the present disclosure, measured by the same method as described above, is preferably 0.1 to 5%, more preferably 0.5 to 4%, and even more preferably 1 to 3%. When the proportion of silanol groups in the polyorganosilsesquioxane of the present disclosure is 0.1% or more, adhesion to the undercoat layer can be easily achieved.

[0152] The polyorganosilsesquioxane of the present disclosure can be produced by known or conventional methods for producing polysiloxanes, and is not particularly limited, but can be produced, for example, by a method of hydrolyzing and condensing one or more hydrolyzable silane compounds.

[0153] Since the polyorganosilsesquioxane of the present disclosure has the above-described structure, a hard coat layer containing the polyorganosilsesquioxane has excellent scratch resistance and toughness.

[0154] In the hard coating agent, the polyorganosilsesquioxane of the present disclosure may be used alone or in combination of two or more types. That is, the hard coating layer may contain either one type of polyorganosilsesquioxane of the present disclosure alone or two or more types.

[0155] The content (blending amount) of the curable polyorganosilsesquioxane resin in the hard coat layer is not particularly limited, but is preferably 70% by mass or more and less than 100% by mass, more preferably 80 to 99.8% by mass, and even more preferably 90 to 99.5% by mass, relative to the total amount of the hard coat layer (total amount of hard coat agent excluding solvent; 100% by mass). By making the content of the curable polyorganosilsesquioxane resin 70% by mass or more, the scratch resistance and toughness of the cured product (coating film) tend to be further improved. On the other hand, by making the content of the curable polyorganosilsesquioxane resin less than 100% by mass, a curing agent can be contained, and curing tends to proceed more efficiently.

[0156] The proportion of the polyorganosilsesquioxane of the present disclosure relative to the total amount (100% by mass) of photocationically curable compounds and photoradically curable compounds contained in the hard coating agent is not particularly limited, but is preferably 70 to 100% by mass, more preferably 75 to 98% by mass, and even more preferably 80 to 95% by mass. By ensuring that the content of the photocationically curable compounds and photoradically curable compounds is 70% by mass or more, the scratch resistance and toughness of the cured product (coating film) tend to be further improved. Note that when only one of the photocationically curable compounds and the photoradically curable compounds is contained, the proportion relative to the total amount is indicated.

[0157] The hard coating agent preferably further contains a curing agent to promote the curing reaction by irradiation with activation energy rays. In particular, it is particularly preferable to contain a photocationic polymerization initiator and / or a photoradical polymerization initiator as the curing agent, in order to further shorten the curing time required to become tack-free.

[0158] As the photocationic polymerization initiator, the same ones as those disclosed in the above-mentioned curable composition can be used.

[0159] The photoradical polymerization initiator is a compound capable of initiating or accelerating the photoradical polymerization reaction of a photoradical curable compound such as the polyorganosilsesquioxane of the present disclosure. Examples of the photoradical polymerization initiator include alkylphenone-based photoradical polymerization initiators, acylphosphine oxide-based photoradical polymerization initiators, oxime ester-based photoradical polymerization initiators, and α-hydroxyketone-based photoradical polymerization initiators.

[0160] In the hard coating agent, the curing agent may be used alone or in combination of two or more.

[0161] The content (blending amount) of the curing agent in the hard coating agent is not particularly limited, but is preferably 0.01 to 10.0 parts by mass, more preferably 0.05 to 5.0 parts by mass, and even more preferably 0.1 to 3.0 parts by mass, relative to the total amount (100 parts by mass; total amount of active energy ray-curable compounds) of the polyorganosilsesquioxane of the present disclosure and the other active energy ray-curable compounds described below. By setting the content of the curing agent to 0.01 parts by mass or more, the curing reaction can be efficiently and sufficiently progressed, and the scratch resistance and toughness of the cured product (coating film) tend to be further improved. On the other hand, by setting the content of the curing agent to 5.0 parts by mass or less, the shelf life of the hard coating agent tends to be further improved, and discoloration of the cured product (coating film) tends to be suppressed.

[0162] The hard coating agent may further contain an active energy ray-curable compound other than the polyorganosilsesquioxane of the present disclosure (sometimes referred to as "other active energy ray-curable compounds"). Examples of the other active energy ray-curable compounds include photocationically curable compounds other than the polyorganosilsesquioxane of the present disclosure (sometimes referred to as "other photocationically curable compounds") and / or photoradical-curable compounds other than the polyorganosilsesquioxane of the present disclosure (sometimes referred to as "other photoradical-curable compounds").

[0163] As the other photocationically curable compound, known or commonly used photocationically curable compounds can be used, and are not particularly limited, but examples thereof include epoxy compounds other than the polyorganosilsesquioxanes of the present disclosure, oxetane compounds, vinyl ether compounds, etc. In addition, in the hard coating agent, one type of other photocationically curable compound can be used alone, or two or more types can be used.

[0164] Examples of the epoxy compound and the oxetane compound include the same compounds as those described above in relation to the curable composition.

[0165] In the hard coating agent, it is preferable to use an epoxy compound as another photocationically curable compound together with the polyorganosilsesquioxane of the present disclosure.

[0166] As the other photoradical curable compound, known or commonly used photoradical curable compounds can be used, and are not particularly limited, but examples thereof include compounds other than the polyorganosilsesquioxanes of the present disclosure that have one or more photoradical polymerizable groups in one molecule, such as a (meth)acrylic group, a (meth)acryloxy group, a (meth)acrylamino group, a vinyl ether group, a vinylaryl group, or a vinyloxycarbonyl group. Note that, in the hard coating agent, one type of other photoradical curable compound can be used alone, or two or more types can be used.

[0167] When the hard coating agent contains other active energy ray-curable compounds, their content (blending amount) is not particularly limited, but is preferably 3 to 50 mass %, more preferably 5 to 40 mass %, and even more preferably 7 to 30 mass %, based on the total amount of the polyorganosilsesquioxane of the present disclosure and other active energy ray-curable compounds (100 mass %; total amount of active energy ray-curable compounds). By setting the content of other active energy ray-curable compounds to 50 mass % or less, the scratch resistance and toughness of the cured product (coating film) tend to be further improved. On the other hand, by setting the content of other active energy ray-curable compounds to 3 mass % or more, it may be possible to impart desired properties to the hard coating agent or cured product (coating film) (for example, rapid curing of the hard coating agent, viscosity adjustment, etc.).

[0168] The hard coating agent preferably contains a compound having one or more thermally polymerizable functional groups and one or more photopolymerizable functional groups in one molecule (hereinafter, sometimes referred to as "compound A"). By containing compound A together with the polyorganosilsesquioxane of the present disclosure, the hard coating agent can effectively increase the crosslink density when cured, making it easier to impart high surface hardness and excellent adhesion to the cured product (coating film).

[0169] The "thermally polymerizable functional group" possessed by compound A is not particularly limited as long as it is a functional group that imparts thermal polymerizability to compound A, and examples thereof include a hydroxyl group, an epoxy group, an oxetanyl group, a vinyl ether group, etc. From the viewpoint of the surface hardness of the coating film of the present disclosure, a hydroxyl group or an epoxy group is preferred. When compound A has two or more thermally polymerizable functional groups, these thermally polymerizable functional groups may be the same or different.

[0170] The "photopolymerizable functional group" possessed by compound A is not particularly limited as long as it is a functional group that imparts polymerizability to compound A by light (e.g., ultraviolet light), and examples thereof include a (meth)acryloyl group and a vinyl group, with a (meth)acryloyl group being preferred from the viewpoint of the surface hardness of the coating film of the present disclosure. When compound A has two or more photopolymerizable functional groups, these photopolymerizable functional groups may be the same or different.

[0171] The number of thermally polymerizable functional groups that compound A has in one molecule may be 1 or more and is not particularly limited, but for example, it is preferably 1 to 5, more preferably 1 to 3, and even more preferably 1 or 2. The number of photopolymerizable functional groups that compound A has in one molecule may be 1 or more and is not particularly limited, but for example, it is preferably 1 to 5, more preferably 1 to 3, and even more preferably 1 or 2.

[0172] The functional group equivalent of the thermally polymerizable functional 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. If the functional group equivalent is less than 50, the hardness of the cured product (coating film) may be insufficient. On the other hand, if the functional group equivalent is more than 500, the surface hardness of the cured product (coating film) may decrease. The functional group equivalent of the thermally polymerizable functional group of compound A can be calculated using the following formula. [Functional group equivalent of thermally polymerizable functional group]=[Molecular weight of compound A] / [Number of thermally polymerizable functional groups in compound A]

[0173] The functional group equivalent of the photopolymerizable functional 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. If the functional group equivalent is less than 50, the hardness of the cured product (coating film) may be insufficient. On the other hand, if the functional group equivalent is more than 500, the surface hardness of the cured product (coating film) may decrease. The functional group equivalent of the photopolymerizable functional group of compound A can be calculated using the following formula. [Functional group equivalent of photopolymerizable functional group]=[Molecular weight of compound A] / [Number of photopolymerizable functional groups in compound A]

[0174] 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, bisphenol B, bisphenol C, bisphenol D, bisphenol E, bisphenol G, bisphenol G, bisphenol H, bisphenol G, bisphenol I, bisphenol I, bisphenol I, bisphenol I, bisphenol I, bisphenol I, bisphenol I, bisphenol I, bisphenol I, bisphenol I, bisphenol A, bisphenol I, bisphenol I, bisphenol I, bisphenol A, bisphenol I, bisphenol I, bisphenol A, bisphenol B, bisphenol A, bisphenol A, bisphenol B, bisphenol A, bisphenol B, bisphenol A, bisphenol B, bisphenol A, bisphenol B, bisphenol A, bisphenol B, bisphenol A, bisphenol B, bisphenol A, bisphenol B, bisphenol C, bisphenol A, bisphenol B ... B, bisphenol C, bisphenol A, bisphenol B, bisphenol A, bisphenol B, bisphenol B, bisphenol C, bisphenol A, bisphenol B, bisphenol B, bisphenol A, bisphenol B, bisphenol B, bisphenol C, bis 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 of the epoxy groups of bisphenol A diglycidyl ether with (meth)acrylic acid or its derivative), bisphenol F epoxy di(meth)acrylate, bisphenol F epoxy half (meth)acrylate, bisphenol S epoxy di(meth)acrylate, bisphenol S epoxy half (meth)acrylate p) acrylates and the like, compounds having an epoxy group and / or a hydroxyl group and a (meth)acryloyl group in one molecule; 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 the like, compounds having an oxetanyl group and a (meth)acryloyl group in one molecule; 2-vinyloxyethyl (meth)acrylate, 3-vinyloxyethyl (meth)acrylate, vinyloxypropyl, 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.

[0175] From the viewpoint of the hardness of the cured product (coating film) and the surface hardness, Compound A is preferably a compound having an epoxy group and / or a hydroxyl group as a thermally polymerizable functional group and a (meth)acryloyl group as a photopolymerizable functional group in one molecule, and specifically, preferred examples include 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, and bisphenol S epoxy half(meth)acrylate.

[0176] In the hard coating agent, the compound A can be used alone or in combination of two or more. The compound A can be produced by a known method, for example, by reacting a part of the thermally polymerizable functional groups of a compound having two or more thermally polymerizable functional groups (e.g., epoxy group, hydroxyl group) in one molecule with a carboxylic acid having a photopolymerizable functional group (e.g., acrylic acid, methacrylic acid, etc.) or a derivative thereof.

[0177] The content (blending amount) of the compound A in the hard coating agent is not particularly limited, but is preferably 1.0 to 100 parts by mass, more preferably 1.3 to 75 parts by mass, and even more preferably 1.5 to 50 parts by mass, based on 100 parts by mass of the total amount of the polyorganosilsesquioxane of the present disclosure and other active energy ray-curable compounds (total amount of active energy ray-curable compounds) in terms of solid content. By setting the content of compound A to 1 part by mass or more, the hardness of the cured product (coating film) tends 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 cured product (coating film) tends to be maintained.

[0178] The hard coating agent preferably contains a surface conditioner. The surface conditioner can be a known or conventional compound added for purposes such as defoaming, leveling, and anti-foaming. Examples of the defoaming agent, leveling agent, and anti-foaming agent include aqueous or non-aqueous compounds composed primarily of polymers such as butadiene, acrylic, and olefin, or silicone-based components such as silicone and fluorine-modified silicone. Among these, the aqueous or non-aqueous compound composed primarily of silicone-based components preferably contains a radical-curable polyorganosiloxane. The use of the radical-curable polyorganosiloxane improves the smoothness of the hard coating layer surface, provides excellent resistance to sebum adhesion, and reduces fingerprints on the surface. Furthermore, the radical-curable polyorganosiloxane is preferably not a compound that falls under the PFAS category. In this case, the above-described effects are exhibited despite not being a compound that falls under the PFAS category. The radical-curable polyorganosiloxane has radical curability and therefore also falls under the category of the curable compound. The radical-curable polyorganosiloxanes may be used singly or in combination of two or more.

[0179] The radically curable polyorganosiloxane has a radically polymerizable functional group in the molecule, such as a photo-radical polymerizable functional group.

[0180] 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.

[0181] 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.

[0182] The content (blending amount) of the surface conditioner in the hard coating agent is not particularly limited, but is, as solids, for example, 0.01 to 15 parts by mass, preferably 0.05 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, and even more preferably 0.2 to 3 parts by mass per 100 parts by mass of the total amount of the polyorganosilsesquioxane of the present disclosure and other active energy ray-curable compounds (total amount of active energy ray-curable compounds). By making the content of the surface conditioner 0.01 part by mass or more, the leveling properties of the cured product (coating film) tend to be further improved.

[0183] The hard coating agent preferably contains an antioxidant. When the hard coating agent contains an antioxidant, the surface hardness of the cured product (coating film) tends to be further improved. As the antioxidant, only one type may be used, or two or more types may be used.

[0184] As the antioxidant, the same antioxidants as those exemplified for the photocurable compound can be used.

[0185] When the hard coating agent contains an antioxidant, its content (blending amount) is not particularly limited, but is preferably 0.05 to 5 parts by mass, more preferably 0.1 to 3 parts by mass, relative to the total amount (100 parts by mass) of the active energy ray-curable compounds contained in the hard coating agent. When the content of the antioxidant is 0.05 parts by mass or more, the storage stability of the cured product (coating film) tends to be sufficient. On the other hand, when the content of the antioxidant is 5 parts by mass or less, coloration of the cured product (coating film) can be suppressed.

[0186] The hard coating agent may preferably further contain a solvent. The solvent is not particularly limited as long as it can dissolve the polyorganosilsesquioxane of the present disclosure and the additives used as needed and does not inhibit polymerization. Only one type of solvent may be used, or two or more types may be used.

[0187] 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 one or more solvents 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).

[0188] The solvent is preferably used so that the concentration of nonvolatile components contained in the hard coating agent is, for example, about 5 to 100% by mass, 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 adjusted to an optimum amount that allows a suitable 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 hard coating agent tends to be low, making it difficult to form a coating film with a suitable film thickness. On the other hand, if the amount of solvent used is too small, the viscosity of the hard coating agent tends to be too high, making it difficult to apply it uniformly to the glass-substitute substrate.

[0189] The hard coating agent may further contain, as other optional 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, benzotriazoline, and the like); The composition may contain conventional additives such as phenol-based UV absorbers, 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, mold 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. These additives may be used alone or in combination of two or more.

[0190] In addition, the hard coating agent is preferably one that does not contain compounds that fall under PFAS. That is, the hard coating layer containing the hard coating agent is preferably one that does not contain compounds that fall under PFAS. By having the above-mentioned configuration, compounds that fall under PFAS are not used, which can comply with environmental regulations and be excellent in safety.

[0191] The hard coating agent 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 hard coating agent 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.

[0192] The hard coating agent is preferably a liquid at room temperature (approximately 25°C), although not particularly limited thereto. More specifically, the viscosity of the hard coating agent at 25°C when diluted with 20% solvent (particularly a hard coating agent 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 setting the viscosity at 300 mPa·s or higher, the properties of the cured product (coating film) tend to be further improved. On the other hand, by setting the viscosity at 20,000 mPa·s or lower, the preparation and handling of the hard coating agent become easier, and air bubbles tend to be less likely to remain in the cured product (coating film). The viscosity of the hard coating agent 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.

[0193] The prepared hard coating agent is applied to the undercoat layer by a known or conventional method, followed by curing, to produce a laminate having a three-layer structure of a substrate, an undercoat layer, and a hard coat layer.

[0194] The hard coat layer can be coated and cured by the same method as that exemplified for the undercoat layer. When the hard coat layer is cured by irradiating it with ultraviolet light, the cumulative irradiation dose is, for example, 1 to 5000 mJ / cm. 2 It is preferable to set it to about this level.

[0195] Specific curing conditions are not particularly limited, but for example, the hard coating agent 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 120°C or higher, and then heat-treating (aging) the composition for 0.5 hours or longer. However, the curing conditions are not limited to these ranges, and the pre-baking temperature, time, and aging temperature 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.

[0196] As described above, the hard coating agent can be applied and cured to form a hard coating layer having high scratch resistance, surface hardness, and toughness. The laminate thus produced can have excellent adhesion and improved surface hardness of the hard coating layer.

[0197] The thickness of the hard coat layer is preferably 0.5 to 50 μm, more preferably 1 to 40 μm, and particularly preferably 3 to 30 μm. When the surface hardness is 0.5 μm or more, it becomes easy to improve the surface hardness.

[0198] It is preferable that the surface of the hard coat layer of the laminate has no tackiness when touched with a finger.

[0199] The pencil hardness of the surface of the hard coat layer of the laminate is preferably 3H or more, more preferably 4H or more. The pencil hardness can be evaluated according to the method described in JIS K5600-5-4 (750g load). When the pencil hardness is 3H or more, the laminate has sufficient surface hardness and tends to have excellent scratch resistance.

[0200] Furthermore, according to JIS K5600-5-6, the laminate is scratched with a cutter blade at 1 mm intervals from the hard coat layer side to create 100 squares in a grid pattern, which are then attached with adhesive tape and peeled off at a 90° angle. When the coating surface is visually inspected for peeling after adhering to the adhesive tape, preferably 90 or more squares remain, more preferably 95 or more squares, and particularly preferably 100. When 90 or more squares remain on the laminate, it can be confirmed that the hard coat layer and undercoat layer exhibit sufficient adhesion.

[0201] [Display device] One embodiment of the present disclosure includes a display device including the laminate. In the display device, the laminate is disposed, for example, so that the hard coat layer forms the surface on the viewing side. The display device is not particularly limited, and examples thereof include organic EL display devices, inorganic EL display devices, and liquid crystal display devices. In the display device, the surface of the hard coat layer has sufficient surface hardness, so that the surface is less likely to be scratched. Furthermore, the display device can also be used as a flexible display that can be bent, rolled, or the like.

[0202] 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]

[0203] Hereinafter, one embodiment of the present disclosure will be described in more detail based on examples.

[0204] 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.

[0205] (Preparation of hard coating agent) A hard coating agent was prepared by mixing each material with the silsesquioxane of Production Example 1 in the composition ratios shown in Table 1. The content ratios shown in Table 1 are the blending ratios of each component, and are solution values for the silsesquioxane of Production Example 1 (active ingredient 77% by mass) and RS-57 (active ingredient 20% by mass), and values for the other components are the active ingredient values.

[0206] [Table 1]

[0207] 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 containing one or more heat-polymerizable functional groups and one or more photopolymerizable functional groups in one molecule) Epolight 1600N: Product name "Epolight 1600N" manufactured by Kyoeisha Chemical Co., Ltd. (Other photocationic curing compounds) RS-57: Product name "Megafac RS-57", manufactured by DIC (surface conditioner) Omnirad127: Product name "Omnirad127", manufactured by IGM Resins BV (photoradical polymerization initiator) CPI-310FG: Product name "CPI-310FG", manufactured by San-Apro Co., Ltd. (photocationic polymerization initiator) ADK STAB AO-02: Product name "ADK STAB AO-02", manufactured by ADEKA Corporation (antioxidant) MIBK: Methyl isobutyl ketone (solvent) MEK: Methyl ethyl ketone (solvent)

[0208] Examples 1 to 6, Comparative Examples 1 to 5 A mixed solution was prepared with the blending ratio shown in Table 2 and used as a curable composition. The curable composition obtained above was applied to the surface of a glass substrate (glass slide) using a wire bar #12 so that the thickness after curing would be 10 μm, and then the applied composition was heated at 3000 mJ / cm 2 using an LED lamp. 2 The film was then heat-treated in an oven at 150°C for 30 minutes to form an undercoat layer.

[0209] Each component listed in Table 2 is described in detail below. KR-470: Product name "KR-470", manufactured by Shin-Etsu Chemical Co., Ltd. (organosiloxane containing two or more alicyclic epoxy groups, number average molecular weight: 740) A-1: 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (alicyclic epoxy compound) A-2: 3,4,3',4'-diepoxybicyclohexyl (alicyclic epoxy compound) YX7400N: Product name "YX7400N", manufactured by Mitsubishi Chemical Corporation (aliphatic epoxy compound) OXT-101: Product name "OXT-101", manufactured by Toagosei Co., Ltd. (oxetane compound) SQ502-8: Product name "COMPOCERAN SQ502-8", manufactured by Arakawa Chemical Industries, Ltd. (a polyorganosiloxane having silanol groups, with a T1 content of 25%, a T2 content of 63%, and a T3 content of 12%) E103-D: Product name "COMPOCERAN E103-D", manufactured by Arakawa Chemical Industries, Ltd. (polyorganosiloxane with silanol groups) CPI-101A: Product name "CPI-101A", manufactured by San-Apro Co., Ltd. (photopolymerization initiator) CPI-100P: Product name "CPI-100P", manufactured by San-Apro Co., Ltd. (photopolymerization initiator) PEP-36: Trade name "ADEKA STAB PEP-36", manufactured by ADEKA Corporation (antioxidant) GA-80: Product name "Sumilizer GA-80", manufactured by Sumitomo Chemical Co., Ltd. (antioxidant)

[0210] The hard coating agent prepared in Production Example 1 was further applied onto the undercoat layer using a wire bar #24 so that the thickness of the hard coating layer after curing would be 20 μm, and the coating was then left in an oven at 80° C. for 1 minute, then in an oven at 120° C. for 2 minutes, and then irradiated with 300 mJ / cm 2 using a high-pressure mercury lamp. 2 The hard coating agent was then cured by heat treatment in an oven at 120° C. for 60 minutes, thereby producing laminates of Examples 1 to 6 and Comparative Examples 1 to 5.

[0211] [evaluation] The laminates of Examples 1 to 6 and Comparative Examples 1 to 5 were subjected to the following evaluations, and the results are shown in Table 2.

[0212] (1) Tackiness after curing The tackiness was confirmed by finger touching the surfaces of the laminates of Examples 1 to 6 and Comparative Examples 1 to 5. If there was tackiness, it was rated as △, and if there was no tackiness, it was rated as ◯.

[0213] (2) Adhesion test The surface of the hard coat layer of each of the laminates of Examples 1 to 6 and Comparative Examples 1 to 5 was scratched with a cutter blade at 1 mm intervals to create a grid of 100 squares according to JIS K5600-5-6, which were then attached with adhesive tape and peeled off at a 90° angle to visually check whether the coating surface adhered to the adhesive tape and then peeled off. A rating of ⊚ was given for 100 squares that adhered, ◯ for 90 or more squares, and × for less than 90 squares.

[0214] (3) Pencil hardness The pencil hardness of the surface of the hard coat layer of each of the laminates of Examples 1 to 6 and Comparative Examples 1 to 5 was measured in accordance with JIS K5600-5-4 (750 g load).

[0215] [Table 2]

[0216] As shown in Table 2, it was confirmed that the curable composition of the present disclosure exhibits sufficient adhesion and excellent surface hardness by containing a first epoxy compound, which is an organosiloxane containing two or more alicyclic epoxy groups, a second epoxy compound, a polyorganosiloxane having silanol groups, and a third epoxy compound or oxetane compound (Examples 1 to 6). On the other hand, when the polyorganosiloxane having silanol groups was not contained, the adhesion was poor (Comparative Examples 1 and 2), and when the composition was changed to improve adhesion without containing the polyorganosiloxane having silanol groups, the surface hardness was poor (Comparative Examples 3 to 5).

[0217] Variations of the invention according to the present disclosure are described below. [Appendix 1] A curable composition comprising a first epoxy compound as a curable compound, which is an organosiloxane containing two or more alicyclic epoxy groups, a second epoxy compound, a polyorganosiloxane having a silanol group, and a third epoxy compound or an oxetane compound. [Appendix 2] 2. The curable composition according to claim 1, comprising the first epoxy compound, the second epoxy compound, the polyorganosiloxane having a silanol group, and the oxetane compound. [Appendix 3] 3. The curable composition according to claim 1, wherein the content of the first epoxy compound is 30 to 70% by mass based on the total amount of the curable compounds. [Appendix 4] 4. The curable composition according to any one of claims 1 to 3, wherein the content of the second epoxy compound is 20 to 60 mass % based on the total amount of the curable compounds. [Appendix 5] 5. The curable composition according to any one of claims 1 to 4, wherein the content of the oxetane compound is 5 to 25 mass % based on the total amount of the curable compounds. [Appendix 6] 6. The curable composition according to any one of claims 1 to 5, wherein the content of the polyorganosiloxane having a silanol group is 1 to 15 mass % based on the total amount of the curable compounds. [Appendix 7] 7. The curable composition according to any one of claims 1 to 6, which does not contain any deleterious substance. [Appendix 8] 8. The curable composition according to any one of claims 1 to 7, wherein the curable composition does not contain any compound that falls under PFAS. [Appendix 9] An undercoat layer comprising a cured product of the curable composition according to any one of Appendices 1 to 8. [Appendix 10] 10. The undercoat layer according to claim 9, having a thickness of 0.1 to 20 μm. [Appendix 11] A laminate comprising a substrate, an undercoat layer according to appendix 9 or 10 formed on at least one surface of the substrate, and a hard coat layer laminated in this order. [Appendix 12] 12. The laminate according to claim 11, wherein the substrate is a glass substrate. [Appendix 13] 13. The laminate according to claim 11, wherein the hard coat layer contains a curable polyorganosilsesquioxane resin as the curable resin. [Appendix 14] 14. The laminate according to any one of claims 11 to 13, wherein the hard coat layer has a surface with a pencil hardness of 3H or more. [Appendix 15] 15. The laminate according to any one of claims 11 to 14, wherein 100 squares are formed in a grid pattern at 1 mm intervals on the surface of the hard coat layer, and when adhesive tape is attached and peeled off in a 90° direction, 90 or more squares remain. [Appendix 16] 16. The laminate according to any one of claims 11 to 15, wherein the hard coat layer does not contain any compound that falls under PFAS. [Appendix 17] A display device comprising the laminate according to any one of appendices 11 to 16.

Claims

1. A curable composition comprising a first epoxy compound as a curable compound, which is an organosiloxane containing two or more alicyclic epoxy groups, a second epoxy compound, a polyorganosiloxane having a silanol group, and a third epoxy compound or an oxetane compound.

2. The curable composition according to claim 1, comprising the first epoxy compound, the second epoxy compound, the polyorganosiloxane having a silanol group, and the oxetane compound.

3. The curable composition according to claim 1 or 2, wherein the content of the first epoxy compound is 30 to 70 mass % based on the total amount of the curable compounds.

4. The curable composition according to claim 1 or 2, wherein the content of the second epoxy compound is 20 to 60 mass % based on the total amount of the curable compounds.

5. 3. The curable composition according to claim 1, wherein the content of the oxetane compound is 5 to 25% by mass based on the total amount of the curable compounds.

6. The curable composition according to claim 1 or 2, wherein the content of the polyorganosiloxane having a silanol group is 1 to 15 mass% based on the total amount of the curable compound.

7. The curable composition according to claim 1 or 2, which does not contain any deleterious substances.

8. The curable composition according to claim 1 or 2, which does not contain any compound that falls under PFAS.

9. An undercoat layer comprising a cured product of the curable composition according to claim 1 or 2.

10. 10. The undercoat layer according to claim 9, which has a thickness of 0.1 to 20 μm.

11. A laminate comprising a substrate, the undercoat layer according to claim 9 formed on at least one surface of the substrate, and a hard coat layer laminated in this order.

12. The laminate according to claim 11, wherein the substrate is a glass substrate.

13. The laminate according to claim 11, wherein the hard coat layer contains a curable polyorganosilsesquioxane resin as the curable resin.

14. The laminate according to claim 11, wherein the hard coat layer has a surface with a pencil hardness of 3H or more.

15. The laminate according to claim 11, wherein 100 squares are formed in a grid pattern at 1 mm intervals on the surface of the hard coat layer, and when an adhesive tape is attached and peeled off in a 90° direction, 90 or more squares remain.

16. The laminate according to claim 11, wherein the hard coat layer does not contain any compound that falls under PFAS.

17. A display device comprising the laminate according to claim 11.

Images