Curable composition, undercoat layer, laminate, and display device

Abstract

The objective is to provide a curable composition that exhibits excellent adhesion to the substrate and the hard coat layer, and that can form a layer that exhibits high surface hardness when the hard coat layer is laminated. [Solution] The curable composition of the present disclosure is characterized by comprising 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 oxetane compound. Preferably, the composition comprises the first epoxy compound, the second epoxy compound, the polyorganosiloxane having a silanol group, and the oxetane compound.

Description

[Technical Field]

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

[0002] For displays in televisions, personal computers, smartphones, and other devices, as well as films used for these displays, where transparency and aesthetics are important, it is common practice to apply a hard coat layer to the surface of such items (substrates) in order to improve scratch resistance (i.e., the ability to prevent damage from abrasion and scratching).

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

[0004] [Patent Document 1] Japanese Patent Publication No. 2003-55601 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, even with the use of an undercoat layer, the problem of insufficient adhesion between the undercoat layer and a hard coat layer of a specific composition persisted.

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

[0007] This disclosure solves the above-mentioned problems, and its purpose is to provide a curable composition that has excellent adhesion to a substrate and a hard coat layer, and that can form a layer that exhibits high surface hardness when a hard coat layer is laminated. [Means for solving the problem]

[0008] The inventors of this disclosure have found that a curable composition comprising 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 oxetane compound exhibits excellent adhesion to a substrate and a hard coat layer, and high surface hardness when a hard coat layer is laminated. This disclosure is completed based on these findings.

[0009] In other words, the present disclosure provides a curable composition comprising 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 oxetane compound.

[0010] The curable composition preferably comprises the first epoxy compound, the second epoxy compound, the polyorganosiloxane having a silanol group, and the oxetane compound.

[0011] The curable composition described above preferably contains 30 to 70% by mass of the first epoxy compound relative to the total amount of the curable compound.

[0012] The curable composition described above preferably contains 20 to 60% by mass of the second epoxy compound relative to the total amount of the curable compound.

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

[0014] The above curable composition preferably contains 1 to 15% by mass of the polyorganosiloxane having the silanol group relative to the total amount of the curable compound.

[0015] The above-mentioned curable composition preferably does not contain hazardous substances.

[0016] The above curable composition preferably does not contain compounds corresponding to PFAS.

[0017] Furthermore, this disclosure provides an undercoat layer containing a cured product of the above-mentioned curable composition.

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

[0019] Furthermore, this disclosure provides a laminate in which a substrate, an undercoat layer formed on at least one surface of the substrate, and a hardcoat layer are laminated in this order.

[0020] In the above laminate, it is preferable that the substrate is a glass substrate.

[0021] In the above laminate, it is preferable that the hard coat layer contains a curable polyorganosilsesquioxane resin as the curable resin.

[0022] Preferably, the laminate has a pencil hardness of 3H or higher on the surface of the hard coat layer.

[0023] In the above laminate, it is preferable that 100 grid-like squares are created on the surface of the hard coat layer at 1 mm intervals, adhesive tape is applied, and when peeled off in a 90° direction, 90 or more squares remain.

[0024] It is preferable that the above laminate does not contain any compounds corresponding to PFAS in the hard coat layer.

[0025] Furthermore, this disclosure provides an image display device comprising the above-mentioned laminate. [Effects of the Invention]

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

[0027] [Figure 1] This figure shows the 29Si-NMR spectrum of one embodiment of a polyorganosiloxane having a silanol group. [Modes for carrying out 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 this disclosure 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 oxetane compound.

[0030] Furthermore, the above-mentioned curable composition may be a photocurable composition, a thermocurable composition, or a curable composition that combines both photocurability and thermocurability. Among these, the above-mentioned curable composition is preferably a photocurable composition.

[0031] <Organosiloxane (first epoxy compound) containing two or more alicyclic epoxy groups> The above curable composition contains a first epoxy compound which is an organosiloxane containing two or more alicyclic epoxy groups. The first epoxy compound has two or more alicyclic epoxy groups in its molecule and further has at least a siloxane skeleton composed of siloxane bonds (Si-O-Si). The siloxane skeleton includes cyclic siloxane skeletons, linear or branched silicones (linear or branched polysiloxanes), cage-type or ladder-type polysilsesquioxanes, and the like. In this disclosure, compounds having a cyclic siloxane skeleton are preferred in that they can achieve both ease of coating and adhesion to the substrate. The first epoxy compound may be used alone or two or more.

[0032] Furthermore, if 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 presence of silanol groups in the first epoxy compound is preferably less than 5%, more preferably 1% or less, and even more preferably 0%. In other words, it is preferable that the first epoxy compound does not contain silanol groups. The presence of silanol groups can be measured by the same method as for measuring polyorganosiloxanes having silanol groups as described below.

[0034] The number-average molecular weight (Mn) of the first epoxy compound described above, measured by gel permeation chromatography on a standard polystyrene basis, is not particularly limited, but is preferably 200 to less than 3000, more preferably 300 to 2000, and even more preferably 400 to 800.

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

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

[0037] Furthermore, the aliphatic hydrocarbon ring forming the cyclic olefin group in the above-mentioned epoxidized cyclic olefin group may have one or more substituents attached. Examples of such substituents include substituents having 0 to 20 carbon atoms (more preferably 0 to 10 carbon atoms), and more specifically, halogen atoms such as fluorine, chlorine, bromine, and iodine atoms; hydroxyl groups; alkoxy groups such as methoxy, ethoxy, propoxy, isopropyloxy, butoxy, and isobutyloxy groups (preferably C 1-6 Alkoxy group, more preferably C 1-4 Alkoxy group; alkenyloxy group such as allyloxy group (preferably C 2-6an alkenyloxy group, more preferably a C 2-4 alkenyloxy group); a phenoxy group, a tolyloxy group, a naphthyloxy group, etc., an aryloxy group having a substituent such as a C 1-4 alkyl group, a C 2-4 alkenyl group, a halogen atom, a C 1-4 alkoxy group, etc. (preferably a C 6-14 aryloxy group); an aralkyloxy group such as a benzyloxy group, a phenethyloxy group, etc. (preferably a C 7-18 aralkyloxy group); an acyloxy group such as an acetyloxy group, a propionyloxy group, a (meth)acryloyloxy group, a benzoyloxy group, etc. (preferably a C 1-12 acyloxy group); a mercapto group; an alkylthio group such as a methylthio group, an ethylthio group, etc. (preferably a C 1-6 alkylthio group, more preferably a C 1-4 alkylthio group); an alkenylthio group such as an allylthio group, etc. (preferably a C 2-6 alkenylthio group, more preferably a C 2-4 alkenylthio group); a arylthio group such as a phenylthio group, a tolylthio group, a naphthylthio group, etc., having a substituent such as a C 1-4 alkyl group, a C 2-4 alkenyl group, a halogen atom, a C 1-4 alkoxy group, etc. (preferably a C 6-14 arylthio group); an aralkylthio group such as a benzylthio group, a phenethylthio group, etc. (preferably a C 7-18 aralkylthio group); a carboxy group; an alkoxycarbonyl group such as a methoxycarbonyl group, an ethoxycarbonyl group, a propoxycarbonyl group, a butoxycarbonyl group, etc. (preferably a C 1-6 alkoxy-carbonyl group); an aryloxycarbonyl group such as a phenoxycarbonyl group, a tolyloxycarbonyl group, a naphthyloxycarbonyl group, etc. (preferably a C 6-14 aryloxy-carbonyl group); an aralkyloxycarbonyl group such as a benzyloxycarbonyl group, etc. (preferably a C 7-18Aralkyloxy-carbonyl group; amino group; mono or dialkylamino 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 groups such as ethyloxetanyloxy group; acyl groups such as acetyl group, propionyl group, and benzoyl group; oxo group; two or more of these as needed. 1-6 Examples include groups bonded via alkylene groups.

[0038] In particular, the above 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 above 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 above first epoxy compound may have one type of epoxidized cyclic olefin group, or it may have two or more types.

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

[0040] Examples of the first epoxy compound mentioned above include 2,4-di[2-(3-{oxabicyclo[4.1.0]heptyl})ethyl]-2,4,6,6,8,8-hexamethylcyclotetrasiloxane, 4,8-di[2-(3-{oxabicyclo[4.1.0]heptyl})ethyl]-2,2,4,6,6,8-hexamethylcyclotetrasiloxane, 2,4-di[2-(3-{oxabicyclo[4.1.0]heptyl})ethyl]-6,8-dipropyl-2,4,6,8-tetramethylcyclotetrasiloxane, and 4,8-di[2-(3-{oxabicyclo[4.1.0]heptyl})ethyl]-2,6-dipropyl Examples include ropyl-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 this disclosure is preferably 30 to 70% by mass, more preferably 35 to 65% by mass, and even more preferably 40 to 60% by mass, based on the total amount (100% by mass) of the curable compound. Being within this range allows the curable composition to be easily coated onto a substrate, and furthermore, the coated substrate exhibits excellent adhesion.

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

[0043] Examples of the second epoxy compound include alicyclic epoxy compounds, aliphatic epoxy compounds, aromatic epoxy compounds, etc., other than the first epoxy compound. From the viewpoint of exhibiting ease of coating onto the substrate when combined with the first epoxy compound, the second epoxy compound is preferably an alicyclic epoxy compound.

[0044] Other alicyclic epoxy compounds include, for example, the compound represented by the following formula (a1).

[0045] [ka]

[0046] In formula (a1) above, R is 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 linked group (a divalent group having one or more atoms; excluding groups containing a siloxane bond). Examples of linked groups include divalent hydrocarbon groups, carbonyl groups, ether bonds, ester bonds, carbonate groups, amide groups, and groups in which multiple of these are linked. Examples of divalent hydrocarbon groups include divalent aliphatic hydrocarbon groups, divalent alicyclic hydrocarbon groups, and groups in which multiple of these are linked. Examples of divalent aliphatic hydrocarbon groups include linear or branched alkylene groups such as methylene groups, methylmethylene groups, dimethylmethylene groups, ethylene groups, propylene groups, trimethylene groups, and tetramethylene groups (for example, alkylene groups having 1 to 6 carbon atoms). Furthermore, examples of divalent alicyclic hydrocarbon groups include divalent cycloalkylene groups such as 1,2-cyclopentylene, 1,3-cyclopentylene, 1,2-cyclohexylene, 1,3-cyclohexylene, and 1,4-cyclohexylene. Examples of compounds represented by the above formula (a1) include compounds in which both R are cyclohexene oxide groups (in particular, compounds in which the carbon atoms at position 4 of the two cyclohexene oxide groups (with the positions of the two carbon atoms forming the epoxy group being considered as positions 1 and 2) are linked by a single bond or a divalent hydrocarbon group).

[0047] Examples of alicyclic epoxy compounds 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, 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, and the like.

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

[0049] [ka]

[0050] In formula (b1), R i The group obtained by subtracting q -OH groups from a q-valent alcohol is p and q, where p and q are natural numbers. i Examples of -(OH)q] include polyhydric alcohols such as 2,2-bis(hydroxymethyl)-1-butanol (alcohols with 1 to 15 carbon atoms). Q is preferably 1 to 6, and p is preferably 1 to 30. When q is 2 or more, the p values ​​in two or more groups in parentheses may be the same or different. Specific examples of the above compound include the 1,2-epoxy-4-(2-oxyranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol, trade name "EHPE3150" (manufactured by Daicel Corporation).

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

[0052] Examples of the above-mentioned aliphatic epoxy compounds include glycidyl ethers of alcohols (where q is a natural number) that do not have a cyclic structure with a q-valence; 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.]; epoxides of oils and fats having double bonds, such as epoxides of linseed oil, epoxides of soybean oil, and epoxides of castor oil; and epoxides of polyolefins (including polyalkadienes), such as epoxides of polybutadiene.

[0053] Examples of alcohols that do not have a cyclic structure with a q-valent value 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 polyhydric alcohols with a trivalent or higher value, such as glycerin, diglycerin, erythritol, trimethylolethane, trimethylolpropane, pentaerythritol, dipentaerythritol, and sorbitol. Examples of alcohols with a q-valent value 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 the condensation reaction of bisphenols [e.g., bisphenol A, bisphenol F, bisphenol S, fluorenebisphenol, etc.] with epihalohydrins; high molecular weight epibis-type glycidyl ether epoxy resins obtained by further addition reactions of these epibis-type glycidyl ether epoxy resins with the above bisphenols; and phenols [e.g., phenol, cresol, xylenol, resorcinol, catechol, bisphenol A, bisphenol]. Examples include novolac alkyl-type glycidyl ether epoxy resins obtained by condensing polyhydric alcohols obtained by condensing polyhydric alcohols [e.g., formaldehyde, acetaldehyde, benzaldehyde, hydroxybenzaldehyde, salicylaldehyde, etc.] with epihalohydrins, and epoxy compounds in which two phenol skeletons are bonded to the 9th position of a fluorene ring, and glycidyl groups are bonded directly or via alkylene oxy groups to the oxygen atoms obtained by removing hydrogen atoms from the hydroxyl groups of these phenol skeletons.

[0055] The content of the second epoxy compound in the curable composition of this disclosure is preferably 20 to 60% by mass, more preferably 25 to 55% by mass, and even more preferably 30 to 50% by mass, based on the total amount (100% by mass) of the curable compound. Being within this range allows the curable composition to be easily coated onto a substrate.

[0056] <Polyorganosiloxanes containing silanol groups> The above curable composition includes the first epoxy compound and the second epoxy compound, as well as a polyorganosiloxane having silanol groups. 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. Furthermore, it is preferable that the polyorganosiloxane having silanol groups differs from the first epoxy compound in terms of the silanol group abundance or the number-average molecular weight, and more preferably in terms of both the silanol group abundance and the 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 polyorganosiloxane having the silanol group, as determined by gel permeation chromatography on a standard polystyrene basis, is not particularly limited, but is preferably 1,000 to 20,000, more preferably 1,500 to 15,000, and even more preferably 2,000 to 10,000.

[0058] The constituent units included in the above-mentioned polyorganosiloxane having a silanol group include [R3SiO 1 / 2 The constituent unit (in M units) represented by [R2SiO 2 / 2 [The constituent unit (D unit) represented by ], [RSiO 3 / 2 The constituent units (T units) represented by ], and [SiO 4 / 2 Examples include constituent units (Q units) represented by ]. In particular, it is preferable that they include the above-mentioned T units.

[0059] The ratio (total amount) of the T unit to the total amount of siloxane constituent units [total amount of M units, D units, T units, and Q units] (100 mol%) in the polyorganosiloxane having the silanol group described above 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 above ratio to 70 mol% or more, the adhesion of the curable composition can be easily improved. There is no particular upper limit, but it may be 100 mol%. The ratio of each siloxane constituent unit in the polyorganosilsesquioxane of this disclosure can be calculated, for example, by the composition of the raw materials or by NMR spectral measurement as described later.

[0060] The silanol group content in the polyorganosiloxane having the silanol group is preferably 5% or more, more preferably 10% or more, even more preferably 15% or more, and particularly preferably 20% or more. A silanol group content of 5% or more facilitates adhesion to the substrate, and while there is no particular upper limit, it may be 50% or less.

[0061] The abundance of the silanol group can be measured by the following method. Figure 1 shows one embodiment of a polyorganosiloxane having a silanol group. 29The spectrum obtained from Si-NMR measurement is shown. The obtained spectrum is separated by waveform, and the peak observed between chemical shifts of -47 ppm and -53 ppm is identified as originating from the T1 structure, the peak observed between -54 ppm and -60 ppm as originating from the T2 structure, and the peak observed between -64 ppm and -70 ppm as originating from the T3 structure. The T1, T2, and T3 structures are defined by the number of silicon atoms bonded via oxygen atoms. At this time, the ratio (%) of the area values ​​of each peak of T1 to T3 to the sum of the area values ​​of all peaks (100%) represents the content ratio (mol%) of each structure (T1 to T3) in the polyorganosiloxane containing silanol groups that is being measured. Using this value and the content ratio of hydroxyl groups to the total number of moles of oxygen atoms and hydroxyl groups in each of the T1 to T3 structures, the total abundance (%) of silanol groups can be calculated according to the following formula. The percentage of silanol groups (%) = (T1 × 2 / 3 + T2 × 1 / 3 + T3 × 0 / 3) In the above formula, T1, T2, and T3 are, respectively, 29 This shows the percentage of the peak area derived from the structure of each silicon atom relative to the total peak area derived from the structure of each silicon atom obtained by Si-NMR measurement (100%), i.e., the content of each structure obtained from the above NMR measurement results.

[0062] Similarly, with respect to the D unit, 29 The spectra obtained from Si-NMR measurements are separated by waveform and identified as originating from the D1 and D2 structures. The D1 and D2 structures are defined based on the number of silicon atoms bonded via oxygen atoms. Furthermore, the total silanol group abundance (%) can be calculated according to the following formula using the same method as described above for T units. The percentage of silanol groups (%) = (D1 × 1 / 2 + D2 × 0 / 2)

[0063] Similarly, with respect to the Q unit, 29The spectra obtained from Si-NMR measurements are separated by waveform and identified as originating from the Q1, Q2, Q3, and Q4 structures. The Q1, Q2, Q3, and Q4 structures are defined based on the number of silicon atoms bonded via oxygen atoms. Furthermore, the total silanol group abundance (%) can be calculated according to the following formula using the same method as described above for the T units. The percentage of silanol groups (%) = (Q1 × 3 / 4 + Q2 × 2 / 4 + Q3 × 1 / 4 + Q4 × 0 / 4)

[0064] By measuring the amount of silanol groups contained in the T, D, and Q units mentioned above and summing them up, the relative abundance of silanol groups in the polyorganosiloxane containing the silanol groups can be calculated.

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

[0066] Furthermore, when the polyorganosiloxane having the silanol group contains T units, the content of the T1 isomer is preferably 5% or more, and more preferably 10% or more, relative to the total (100%) of the T1 to T3 isomers. By having a T1 isomer content of 5% or more, it is possible to ensure a sufficient proportion of silanol groups. There is no particular upper limit, but it may be 50% or less, or 30% or less.

[0067] Furthermore, when the polyorganosiloxane having the silanol group 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 (100%) of the T1 to T3 isomers. By having a T2 isomer content of 30% or more, it is possible to ensure a sufficient proportion of silanol groups. There is no particular upper limit, but it may be 80% or less, or 70% or less.

[0068] Furthermore, if the polyorganosiloxane having the silanol group contains T units, the content of the T3 isomer is preferably 40% or less, and 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 10% or more.

[0069] The polyorganosiloxane having the silanol group described above preferably contains an active energy ray curable functional group. Examples of the active energy ray curable functional group include a photocationic polymerizable functional group and a photoradical polymerizable functional group, and among these, it is preferable that the photocationic polymerizable functional group contains an epoxy group. Examples of the epoxy group include those exemplified as epoxy groups in the first epoxy compound and the second epoxy compound described above, and it is particularly preferable that it contains a glycidyl ether group and the groups exemplified as aromatic epoxy compounds.

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

[0071] <Oxetane compounds> One embodiment of the curable composition of this disclosure includes, in addition to the first epoxy compound, the second epoxy compound, and the polyorganosiloxane having a silanol group, an oxetane compound. The oxetane compound is a compound having at least one oxetanyl group as a cationic polymerizable group in one molecule, and may contain two or more. One or more types of the oxetane compound may be used. The inclusion of the oxetane compound tends to enable the curable composition to exhibit good adhesion to the substrate.

[0072] Examples of the above oxetane compounds 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 Examples include (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, and 3-ethyl-ethyl(3-ethyloxetan-3-yl)methoxy]methyl}oxetane.

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

[0074] Furthermore, the above-mentioned curable composition may also contain, along with the oxetane compound, a third epoxy compound and a fourth epoxy compound, as described later.

[0075] <Third epoxy compound> Furthermore, as another embodiment of the curable composition of this disclosure, it is preferable to include a third epoxy compound, which is not one of the first epoxy compound or the polyorganosiloxane having a silanol group, and is a different component from the second epoxy compound, in addition to the first epoxy compound, the second epoxy compound, and the polyorganosiloxane having a silanol group. In the curable composition described above, the epoxy compound with a higher content is designated as the second epoxy compound, and the epoxy compound with a lower content is designated as the third epoxy compound.

[0076] The third epoxy compound mentioned above can be any epoxy compound other than the one used as the second epoxy compound, from among the epoxy compounds that do not fall under the first epoxy compound and the polyorganosiloxane having a silanol group. Specifically, the second epoxy compound mentioned above can be any of the examples provided.

[0077] In particular, when the second epoxy compound contains an alicyclic epoxy compound, it is preferable that the third epoxy compound contains an aliphatic epoxy compound. Including the aliphatic epoxy compound as the third epoxy compound makes it easier to achieve adhesion to the substrate. The aliphatic epoxy compound exemplified as the aliphatic epoxy compound of the second epoxy compound can be used.

[0078] When the above-mentioned third epoxy compound is included, the content of the third epoxy compound is preferably 5 to 25% by mass, and more preferably 7 to 20% by mass, relative to the total amount (100% by mass) of the curable compound. When the content of the third epoxy compound is within the above range, it becomes easier to achieve adhesion with the substrate.

[0079] Furthermore, the curable composition may further contain epoxy compounds other than the first to third epoxy compounds and the polyorganosiloxane having a silanol group (hereinafter referred to as the "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 from among the epoxy compounds that do not fall under the first epoxy compound. That is, as the fourth epoxy compound, any epoxy compound other than those used as the second and third epoxy compounds can be used from among the epoxy compounds exemplified as the second epoxy compound above. In the curable composition, the fourth epoxy compound is an epoxy compound that is present in a smaller quantity compared to the second and third epoxy compounds. The fourth epoxy compound may be used as a single compound or as two or more compounds.

[0080] Furthermore, if 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, and the like. Only one type of thermosetting resin may be used, or two or more types may be used.

[0081] The above curable composition preferably further contains a curing agent. Known or conventional thermal polymerization initiators and photopolymerization initiators can be used as the curing agent, and it is preferable to use a photopolymerization initiator, and among these, a photocationic polymerization initiator can be preferably used as the photopolymerization initiator. One type of curing agent may be used, or two or more types may be used.

[0082] As the above-mentioned photocationic polymerization initiator, known or conventional photocationic polymerization initiators can be used, for example, sulfonium salts (salts of sulfonium ions and anions), iodonium salts (salts of iodonium ions and anions), selenium salts (salts of selenium ions and anions), ammonium salts (salts of ammonium ions and anions), phosphonium salts (salts of phosphonium ions and anions), and salts of transition metal complex ions and anions.

[0083] Examples of the above sulfonium salts include triphenylsulfonium salt, tri-p-tolylsulfonium salt, tri-o-tolylsulfonium salt, tris(4-methoxyphenyl)sulfonium salt, 1-naphthyldiphenylsulfonium salt, 2-naphthyldiphenylsulfonium salt, tris(4-fluorophenyl)sulfonium salt, tri-1-naphthylsulfonium salt, tri-2-naphthylsulfonium salt, tris(4-hydroxyphenyl)sulfonium salt, diphenyl[4-(phenylthio)phenyl]sulfonium salt, and 4-(p-tolylthio)phenyldi-(p-phenyl)sulfonium salt. Examples include triarylsulfonium salts such as methylsulfonium salt; diarylsulfonium salts such as diphenylphenacylsulfonium salt, diphenyl-4-nitrophenacylsulfonium salt, diphenylbenzylsulfonium salt, and diphenylmethylsulfonium salt; monoarylsulfonium salts such as phenylmethylbenzylsulfonium salt, 4-hydroxyphenylmethylbenzylsulfonium salt, and 4-methoxyphenylmethylbenzylsulfonium salt; and trialkylsulfonium salts such as dimethylphenacylsulfonium salt, phenacyltetrahydrothiophenium salt, and dimethylbenzylsulfonium salt.

[0084] Examples of the above-mentioned diphenyl[4-(phenylthio)phenyl]sulfonium salts include diphenyl[4-(phenylthio)phenyl]sulfonium tetrakis(pentafluorophenyl)borate and diphenyl[4-(phenylthio)phenyl]sulfonium hexafluorophosphate. Commercially available products such as "CPI-100P" (manufactured by Sunapro Co., Ltd., a 50% propylene carbonate solution of diphenyl[4-(phenylthio)phenyl]sulfonium hexafluorophosphate) can also be used.

[0085] Examples of the iodonium salts mentioned above include the product name "RHODORSIL PHOTOINITIATOR 2074" (manufactured by Rhodia Japan, tetrakis(pentafluorophenyl)borate-[(1-methylethyl)phenyl](methylphenyl)iodonium), the product name "WPI-124" (manufactured by Wako Pure Chemical Industries, Ltd.), diphenyliodonium salt, di-p-tolyliodonium salt, bis(4-dodecylphenyl)iodonium salt, and bis(4-methoxyphenyl)iodonium salt.

[0086] Examples of the selenium salts mentioned above include triarylselenium salts such as triphenylselenium salt, tri-p-tolylselenium salt, tri-o-tolylselenium salt, tris(4-methoxyphenyl)selenium salt, and 1-naphthyldiphenylselenium salt; diarylselenium salts such as diphenylphenacylselenium salt, diphenylbenzylselenium salt, and diphenylmethylselenium salt; monoarylselenium salts such as phenylmethylbenzylselenium salt; and trialkylselenium salts such as dimethylphenacylselenium salt.

[0087] Examples of the above ammonium salts include tetraalkylammonium salts such as tetramethylammonium salt, ethyltrimethylammonium salt, diethyldimethylammonium salt, triethylmethylammonium salt, tetraethylammonium salt, trimethyl-n-propylammonium salt, and trimethyl-n-butylammonium salt; pyrrolidium salts such as N,N-dimethylpyrrolidium salt and N-ethyl-N-methylpyrrolidium salt; imidazolinium salts such as N,N'-dimethylimidazolinium salt and N,N'-diethylimidazolinium salt; and N,N'-dimethyltetrahydropyrimidium salt and N,N'-diethyl Examples include tetrahydropyrimidium salts such as trahydropyrimidium salt; morpholinium salts such as N,N-dimethylmorpholinium salt and N,N-diethylmorpholinium salt; piperidinium salts such as N,N-dimethylpiperidinium salt and N,N-diethylpiperidinium salt; pyridinium salts such as N-methylpyridinium salt and N-ethylpyridinium salt; imidazolium salts such as N,N'-dimethylimidazolium salt; quinolium salts such as N-methylquinolium salt; isoquinolium salts such as N-methylisoquinolium salt; thiazonium salts such as benzylbenzothiazonium salt; and acridium salts such as benzylacridium salt.

[0088] Examples of the phosphonium salts mentioned above include tetraarylphosphonium salts such as tetraphenylphosphonium salt, tetra-p-tolylphosphonium salt, and tetrakis(2-methoxyphenyl)phosphonium salt; triarylphosphonium salts such as triphenylbenzylphosphonium salt; and tetraalkylphosphonium salts such as triethylbenzylphosphonium salt, tributylbenzylphosphonium salt, tetraethylphosphonium salt, tetrabutylphosphonium salt, and triethylphenacylphosphonium salt.

[0089] Examples of the above transition metal complex ion salts include (η 5 -cyclopentadienyl)(η 6 -toluene)Cr + , (η 5 -cyclopentadienyl)(η 6 -Xylene)Cr+ Salts of chromium complex cations such as (η 5 -cyclopentadienyl)(η 6 -Toluene)Fe + , (η 5 -cyclopentadienyl)(η 6 -xylene)Fe + Examples include salts of iron complex cations.

[0090] Examples of anions that make up the aforementioned salt include PF6. - BF4 - (C6F5)4B - (C6F5)4Ga - Examples include sulfonate anions, perhalate ions, halogenated sulfonate ions, sulfate ions, carbonate ions, aluminate ions, carboxylate ions, arylborate ions, thiocyanate ions, and nitrate ions.

[0091] The amount of 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, based on the total amount of curable compounds contained in the curable composition (100 parts by mass). By using the curing agent within the above range, a cured product with excellent adhesion to the substrate can be obtained.

[0092] The above curable composition preferably further contains an antioxidant. Known or conventional antioxidants can be used as the antioxidant. One type of antioxidant may be used, or two or more types may be used.

[0093] As antioxidants, known or conventional antioxidants can be used and are not particularly limited, but examples include phenolic antioxidants (phenolic compounds), hindered amine antioxidants (hindered amine compounds), phosphorus antioxidants (phosphorus compounds), sulfur antioxidants (sulfur compounds), etc.

[0094] Examples of the above-mentioned phenolic antioxidants include monophenols such as 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-p-ethylphenol, and stearyl-β-(3,5-di-t-butyl-4-hydroxyphenyl)propionate; 2,2'-methylenebis(4-methyl-6-t-butylphenol), 2,2'-methylenebis(4-ethyl-6-t-butylphenol), 4,4'-thiobis(3-methyl-6-t-butylphenol), 4,4'-butylidenebis(3-methyl-6-t-butylphenol), and 3,9-bis[1,1-dimethyl-2-{β-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy}ethyl]2,4,8 Examples include bisphenols such as ,10-tetraoxaspiro[5.5]undecane; 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, tetrakis[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane, bis[3,3'-bis-(4'-hydroxy-3'-t-butylphenyl)butyric acid]glycol ester, 1,3,5-tris(3',5'-di-t-butyl-4'-hydroxybenzyl)-s-triazine-2,4,6-(1H,3H,5H)trione, and high molecular weight phenols such as tocopherol.

[0095] Examples of the above-mentioned hindered amine antioxidants include bis(1,2,2,6,6-pentamethyl-4-piperidyl)[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]butylmalonate, bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, methyl-1,2,2,6,6-pentamethyl-4-piperidyl sebacate, and 4-benzoyloxy-2,2,6,6-tetramethylpiperidine.

[0096] Examples of the phosphorus-based antioxidants mentioned above include triphenyl phosphite, diphenylisodecyl phosphite, phenyldiisodecyl phosphite, tris(nonylphenyl) phosphite, diisodecylpentaerythritol phosphite, tris(2,4-di-t-butylphenyl) phosphite, cyclic neopentanetetraylbis(octadecyl) phosphite, cyclic neopentanetetraylbis(2,4-di-t-butylphenyl) phosphite, and cyclic neopentanetetraylbis(2 Phosphates such as ,4-di-t-butyl-4-methylphenyl) phosphite and bis[2-t-butyl-6-methyl-4-{2-(octadecyloxycarbonyl)ethyl}phenyl]hydrogen phosphite; and oxaphosphaphenanthrene oxides such as 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and 10-(3,5-di-t-butyl-4-hydroxybenzyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide.

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

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

[0099] The amount of the above-mentioned antioxidant used (amount blended) 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, based on the total amount of the curable compound (100 parts by mass).

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

[0101] Furthermore, it is preferable that the above curable composition does not contain compounds that fall under the category of PFAS. Having the above composition eliminates the use of compounds that fall under the category of PFAS, making it possible to comply with environmental regulations and have superior safety. In this disclosure, "compounds that fall under the category of PFAS" is a general term for perfluoroalkyl compounds and polyfluoroalkyl compounds.

[0102] Furthermore, the curable composition preferably contains 1000 ppm by mass or less of hazardous substances, and more preferably 0 ppm by mass, based on the total amount (100% by mass) of the curable composition. In other words, it is preferable that the curable composition does not contain hazardous substances. Specifically, antimony compounds can be cited as examples of the hazardous substances.

[0103] [Undercoat layer] One embodiment of the present disclosure is an undercoat layer containing a cured product of the curable composition. The undercoat layer can be obtained, for example, by coating the curable composition onto at least one surface of a substrate and curing it.

[0104] The above-mentioned substrate may be a single layer or a multi-layered substrate made of the same or different materials. Furthermore, the above-mentioned substrate can be a resin substrate, a glass substrate, a metal substrate, etc., and a glass substrate is preferred from the viewpoint of adhesion with the above-mentioned undercoat layer.

[0105] Conventional coating methods can be used to form the above-mentioned undercoat layer. 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 method, and organic vapor deposition method can be used. As for the curing treatment, if the above-mentioned curable composition is a photocurable composition, examples of light irradiation using a mercury lamp, xenon lamp, carbon arc lamp, metal halide lamp, sunlight, electron beam source, laser light source, LED light source, etc., can be used. The cumulative irradiation dose is, for example, 300 to 10000 mJ / cm². 2 It is preferable to irradiate within the range in which this occurs. If the curable composition is a thermosetting composition, the treatment may be carried out 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 changed in stages. Alternatively, a film pre-coated on another substrate by the above forming method may be transferred to the substrate using a transfer method such as adhesive transfer, thermal transfer, or UV transfer.

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

[0107] Furthermore, when the undercoat layer is visually inspected after curing, it is preferable that it can be coated without repelling onto the substrate, and it is even more preferable that the surface of the undercoat layer is smooth and can be coated uniformly.

[0108] The thickness of the undercoat layer is preferably 0.1 to 20 μm, and more preferably 1 to 15 μm. A thickness of 0.1 μm or more in the undercoat layer facilitates adhesion between the substrate and the hard coat layer. Furthermore, a thickness of 20 μm or less makes it easier to improve the surface hardness of the hard coat layer when it is laminated.

[0109] [Laminated structure] One embodiment of the present disclosure is a laminate comprising the above-mentioned substrate, the undercoat layer, and the hardcoat layer. The laminate can be manufactured by further forming the hardcoat layer on the undercoat layer formed on the substrate. In the laminate, the laminated structure may be formed on only one surface (one side) of the substrate, or on both surfaces (both sides). Furthermore, the laminate may have layers other than the undercoat layer and the hardcoat layer, and from the viewpoint of exhibiting good adhesion of the laminate, it is preferable that the substrate, undercoat layer, and hardcoat layer are laminated in this order.

[0110] The hard coat layer described above preferably contains a curable resin, and more preferably contains a curable polyorganosilsesquioxane resin, which 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 this disclosure"). In other words, the curable composition for forming the hard coat layer (hereinafter sometimes referred to as "hard coat agent") preferably contains a polyorganosilsesquioxane having a structural unit represented by the following formula (1). As described later, the hard coat agent may also contain other components such as a curing agent (particularly a photocationic polymerization initiator, a photoradical polymerization initiator), and an antioxidant. [ka] [In formula (1), R 1 This indicates a group containing an active energy ray-curable functional group.

[0111] The polyorganosilsesquioxane of this disclosure is characterized by having a structural unit represented by the above formula (1). Furthermore, it is preferable that the polyorganosilsesquioxane of this disclosure has a structural unit represented by the following formula (I) (sometimes referred to as the "T3 isomer") and a structural unit represented by the following formula (II) (sometimes referred to as the "T2 isomer"). In addition, it is preferable that the polyorganosilsesquioxane of this disclosure has a structural unit represented by the following formula (4). [ka] [ka]

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

[0113] R in equation (1) 1 This indicates a group containing an active energy ray-curable functional group (a monovalent group). That is, the polyorganosylsesquioxanes of this disclosure are photocationically curable compounds (photocationically polymerizable compounds) or photoradical-curable compounds (photoradical polymerizable compounds) having at least an active energy ray-curable functional group in their molecule.

[0114] The "photocationic polymerizable functional group" in the group containing the above-mentioned active energy ray curable functional group is not particularly limited as long as it has photocationic polymerizability, and examples include epoxy groups, oxetane groups, vinyl ether groups, vinyl phenyl groups, etc. The "photoradical polymerizable functional group" in the group containing the above-mentioned active energy ray curable functional group is not particularly limited as long as it has photoradical polymerizability, and examples include (meth)acryloxy groups, (meth)acrylamide groups, vinyl groups, vinyl thio groups, etc. From the viewpoint of the surface hardness of the cured product (coating film), epoxy groups, (meth)acryloxy groups, etc. are preferred as the active energy ray curable functional group, and epoxy groups are particularly preferred.

[0115] The epoxy group-containing group mentioned above includes known and conventional groups having an oxirane ring, and is not particularly limited. However, from the viewpoint of the curability of the hard coat agent and the scratch resistance and toughness of the cured product (coating film), the group represented by formula (1a), the group represented by formula (1b), the group represented by formula (1c), and the group represented by formula (1d) are preferred, more preferably the group represented by formula (1a), the group represented by formula (1c), and even more preferably the group represented by formula (1a). [ka] [ka] [ka] [ka]

[0116] In the above formula (1a), R 1aR represents a linear or branched alkylene group. Examples of linear or branched alkylene groups include linear or branched alkylene groups having 1 to 10 carbon atoms, such as methylene group, methylmethylene group, dimethylmethylene group, ethylene group, propylene group, trimethylene group, tetramethylene group, pentamethylene group, hexamethylene group, and decamethylene group. Among these, R 1a From the viewpoint of scratch resistance and toughness of the cured product (coating film), linear alkylene groups having 1 to 4 carbon atoms and branched alkylene groups having 3 or 4 carbon atoms are preferred, more preferably ethylene groups, trimethylene groups, propylene groups, and even more preferably ethylene groups and trimethylene groups.

[0117] In the above formula (1b), R 1b R represents a linear or branched alkylene group. 1a Similar groups are given as examples. Among them, R 1b From the viewpoint of scratch resistance and toughness of the cured product (coating film), linear alkylene groups having 1 to 4 carbon atoms and branched alkylene groups having 3 or 4 carbon atoms are preferred, more preferably ethylene groups, trimethylene groups, propylene groups, and even more preferably ethylene groups and trimethylene groups.

[0118] In the above formula (1c), R 1c R represents a linear or branched alkylene group. 1a Similar groups are given as examples. Among them, R 1c From the viewpoint of scratch resistance and toughness of the cured product (coating film), linear alkylene groups having 1 to 4 carbon atoms and branched alkylene groups having 3 or 4 carbon atoms are preferred, more preferably ethylene groups, trimethylene groups, propylene groups, and even more preferably ethylene groups and trimethylene groups.

[0119] In the above formula (1d), R 1d R represents a linear or branched alkylene group. 1a Similar groups are given as examples. Among them, R 1dFrom the viewpoint of scratch resistance and toughness of the cured product (coating film), linear alkylene groups having 1 to 4 carbon atoms and branched alkylene groups having 3 or 4 carbon atoms are preferred, more preferably ethylene groups, trimethylene groups, propylene groups, and even more preferably ethylene groups and trimethylene groups.

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

[0121] The above-mentioned groups containing the oxetane group include known and conventional groups having an oxetane ring, and are not particularly limited. Examples include the oxetane group itself, and groups obtained by substituting one or more hydrogen atoms (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) with an oxetane group. From the viewpoint of the curability of the hard coat agent and the scratch resistance and toughness of the cured product (coating film), 3-oxetanyl group, oxetane-3-ylmethyl group, 3-ethyloxetane-3-ylmethyl group, 2-(oxetane-3-yl)ethyl group, 2-(3-ethyloxetane-3-yl)ethyl group, 3-(oxetane-3-ylmethoxy)propyl group, and 3-(3-ethyloxetane-3-ylmethoxy)propyl group are preferred.

[0122] The above-mentioned groups containing vinyl ether groups include known and conventional groups having vinyl ether groups, and are not particularly limited. Examples include the vinyl ether group itself, and groups obtained by substituting one or more hydrogen atoms (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) with a vinyl ether group. From the viewpoint of the curability of the hard coat agent and the scratch resistance and toughness of the cured product (coating film), vinyloxymethyl group, 2-(vinyloxy)ethyl group, 3-(vinyloxy)propyl group, etc., are preferred.

[0123] The above-mentioned groups containing vinylphenyl groups include known and conventional groups having vinylphenyl groups, and are not particularly limited. Examples include the vinylphenyl group itself, and groups obtained by substituting one or more hydrogen atoms (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) with a vinylphenyl group. From the viewpoint of the curability of the hard coat agent and the scratch resistance and toughness of the cured product (coating film), 4-vinylphenyl groups, 3-vinylphenyl groups, 2-vinylphenyl groups, etc., are preferred.

[0124] The above-mentioned groups containing the (meth)acrylooxy group include known and conventional groups having a (meth)acrylooxy group, and are not particularly limited. Examples include the (meth)acrylooxy group itself, and groups obtained by substituting 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) with a (meth)acrylooxy group. From the viewpoint of the curability of the hard coat agent (coating film) and the scratch resistance and toughness of the cured product (coating film), 2-((meth)acrylooxy)ethyl group, 3-((meth)acrylooxy)propyl group, etc., are preferred.

[0125] The above-mentioned groups containing a (meth)acrylamide group include known and conventional groups having a (meth)acrylamide group, and are not particularly limited. Examples include the (meth)acrylamide group itself, and groups obtained by substituting 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) with a (meth)acrylamide group. From the viewpoint of the curability of the hard coat agent and the scratch resistance and toughness of the cured product (coating film), 2-((meth)acrylamide)ethyl group, 3-((meth)acrylamide)propyl group, etc., are preferred.

[0126] The above-mentioned vinyl group-containing groups include known and conventional groups having a vinyl group, and are not particularly limited. Examples include the vinyl group itself, and groups obtained by substituting 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) with a vinyl group. From the viewpoint of the curability of the hard coat agent and the scratch resistance and toughness of the cured product (coating film), vinyl groups, vinyl methyl groups, 2-vinyl ethyl groups, 3-vinyl propyl groups, etc., are preferred.

[0127] The above-mentioned groups containing a vinylthio group include known and conventional groups having a vinylthio group, and are not particularly limited. Examples include the vinylthio group itself, and groups obtained by substituting 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) with a vinylthio group. From the viewpoint of the curability of the hard coat agent and the scratch resistance and toughness of the cured product (coating film), vinylthiomethyl group, 2-(vinylthio)ethyl group, 3-(vinylthio)propyl group, etc., are preferred.

[0128] R in equation (1) 1 In terms of the scratch resistance and toughness of the cured product (coating), groups containing epoxy groups and groups containing (meth)acrylooxy groups are preferred, and in particular, groups represented by the above formula (1a) are preferred, R 1a The group is preferably an ethylene group [particularly the 2-(3',4'-epoxycyclohexyl)ethyl group], a 3-(acrylooxy)propyl group, or a 3-(methacrylateoxy)propyl group.

[0129] The polyorganosilsesquioxane of this disclosure may have only one constituent unit represented by formula (1) above, or it may have two or more constituent units represented by formula (1) above.

[0130] The polyorganosilsesquioxanes disclosed herein are silsesquioxane constituent units [RSiO 3 / 2In addition to the constituent units represented by formula (1) above, the system may also have constituent units represented by formula (2) below. [ka]

[0131] The constituent unit represented by the above formula (2) is generally [RSiO 3 / 2 This is a silsesquioxane structural unit (T unit) represented by ]. That is, the structural unit represented by formula (2) above is formed by the hydrolysis and condensation reaction of the corresponding hydrolyzable trifunctional silane compound (specifically, for example, the compound represented by formula (b) described later).

[0132] R in equation (2) above 2 This represents a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted alkenyl group. Examples of the aryl group include phenyl, tolyl, and naphthyl groups. Examples of the aralkyl group include benzyl and phenethyl groups. Examples of the cycloalkyl group include cyclobutyl, cyclopentyl, and cyclohexyl groups. Examples of the alkyl group include linear or branched alkyl groups such as methyl, ethyl, propyl, n-butyl, isopropyl, isobutyl, s-butyl, t-butyl, and isopentyl groups. Examples of the alkenyl group include linear or branched alkenyl groups such as vinyl, allyl, and isopropenyl groups.

[0133] The above-mentioned substituted aryl groups, substituted aralkyl groups, substituted cycloalkyl groups, substituted alkyl groups, and substituted alkenyl groups include groups in which a hydrogen atom or part or all of the main chain skeleton in each of the above-mentioned aryl groups, aralkyl groups, cycloalkyl groups, alkyl groups, and alkenyl groups is substituted with at least one selected from the group consisting of ether groups, ester groups, carbonyl groups, siloxane groups, halogen atoms (such as fluorine atoms), acrylic groups, methacrylic groups, mercapto groups, amino groups, and hydroxyl groups.

[0134] Among them, R 2 The preferred members are substituted or unsubstituted aryl groups, substituted or unsubstituted alkyl groups, and substituted or unsubstituted alkenyl groups; more preferably, substituted or unsubstituted aryl groups; and even more preferably, phenyl groups.

[0135] The proportion of each silsesquioxane constituent unit (constituent unit represented by formula (1), constituent unit represented by formula (2)) in the polyorganosilsesquioxane of this disclosure can be appropriately adjusted by the composition of the raw material (hydrolyzable trifunctional silane) used to form these constituent units.

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

[0137] When the polyorganosylsesquioxane of this disclosure has a constituent unit (T3) represented by formula (I) and a constituent unit (T2) represented by formula (II), the ratio [T3 / T2] is not particularly limited, but can be appropriately selected from a range of, for example, 5 or more (for example, 5 or more and 500 or less). The lower limit of the ratio [T3 / T2] is preferably 20, more preferably 21, more preferably 23, and even more preferably 25. Setting the ratio [T3 / T2] to 5 or more tends to improve the surface hardness, scratch resistance, and toughness of the cured product (coating film). On the other hand, the upper limit of the ratio [T3 / T2] is preferably 500, more preferably 100, more preferably 50, and even more preferably 40. Setting the ratio [T3 / T2] to 500 or less improves compatibility with other components in the hard coat agent and also suppresses viscosity, making it easier to handle and easier to apply as a hard coat agent.

[0138] Furthermore, the constituent unit represented by formula (I) above can be described in more detail as formula (I') below. Similarly, the constituent unit represented by formula (II) above can be described in more detail as formula (II') below. In the structure represented by formula (I') below, the three oxygen atoms bonded to the silicon atom are each bonded to other silicon atoms (silicon atoms not shown in formula (I')). On the other hand, in the structure represented by formula (II') below, the two oxygen atoms located above and below the silicon atom are each bonded to other silicon atoms (silicon atoms not shown in formula (II')). In other words, both the T3 and T2 forms are constituent units (T units) formed by the hydrolysis and condensation reactions of the corresponding hydrolyzable trifunctional silane compounds. [ka] [ka]

[0139] In equation (I) above, R a (R in formula (I')) a (The same applies to R in equation (II))b (R in formula (II')) b (the same also applies to the following), each represents 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. Specific examples of R a and R b include the same ones as R 1 in the above formula (1) and R 2 in the above formula (2). In addition, R a in formula (I) and R b in formula (II) each represent a group bonded to a silicon atom in the hydrolyzable trifunctional silane compound used as a raw material of the polyorganosilsesquioxane of the present disclosure (a group other than an alkoxy group and a halogen atom; for example, R 1 , R 2 in the following formulas (a) to (c), a hydrogen atom, etc.).

[0140] R c (the same also applies to R c in formula (II')) in the above 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 linear or branched alkyl groups 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. The alkyl group in R c in formula (II) generally derives from the alkyl group forming an alkoxy group (for example, an alkoxy group as X 1 to X 3 described later) in the hydrolyzable silane compound used as a raw material of the polyorganosilsesquioxane of the present disclosure.

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

[0142] When the ratio [T3 form / T2 form] of the polyorganosilsesquioxane of the present disclosure is within the above range (for example, 5 or more and 500 or less), it means that a certain amount of T2 form exists with respect to the T3 form in the polyorganosilsesquioxane of the present disclosure. Examples of such T2 forms include a structural unit represented by the following formula (4), a structural unit represented by the following formula (5), a structural unit represented by the following formula (6), and the like. R in the following formula (4) 1 and R in the following formula (5) 2 are the same as R in the above formula (1) 1 and R in the above formula (2) 2 respectively. R in the following formulas (4) to (6) c is R in formula (II).c Similarly, it represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. [ka] [ka] [ka]

[0143] The polyorganosilsesquioxanes of this disclosure may have any of the following silsesquioxane structures: cage-type, incomplete cage-type, ladder-type, or random-type, and may have a combination of two or more of these silsesquioxane structures.

[0144] When the polyorganosilsesquioxane of this disclosure has a constituent unit represented by formula (4) above, the ratio (total amount) of the constituent unit represented by formula (1) above and the constituent unit represented by formula (4) above to the total amount of siloxane constituent units [total amount of all siloxane constituent units; M units, D units, T units, and Q units] (100 mol%) is not particularly limited, but is preferably 55 to 100 mol%, more preferably 65 to 100 mol%, and even more preferably 80 to 99 mol%. By setting the above ratio to 55 mol% or more, the curability of the hard coat agent is improved, and the scratch resistance and toughness of the cured product (coating film) are significantly increased. The ratio of each siloxane constituent unit in the polyorganosilsesquioxane of this disclosure can be calculated, for example, by the composition of the raw materials or by NMR spectrum measurement.

[0145] The ratio (total amount) of the constituent units represented by formula (2) and the constituent units represented by formula (5) in the polyorganosilsesquioxane of this disclosure to the total amount of siloxane constituent units [total amount of all siloxane constituent units; M units, D units, T units, and Q units] (100 mol%) is not particularly limited, but is preferably 0 to 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 ratio to 70 mol% or less, the proportion of the constituent units represented by formula (1) and the constituent units represented by formula (4) can be increased relatively, thereby improving the curability of the hard coat agent and tending to increase the scratch resistance and toughness of the cured product (coating film).

[0146] The proportion (total amount) of the constituent units represented by formula (1), formula (2), formula (4), and formula (5) in the polyorganosilsesquioxane of this disclosure, relative to the total amount of siloxane constituent units [total amount of all siloxane constituent units; M units, D units, T units, and Q units] (100 mol%), is not particularly limited, but is preferably 60 to 100 mol%, more preferably 70 to 100 mol%, and even more preferably 80 to 100 mol%. Setting the above proportion to 60 mol% or more tends to increase the scratch resistance and toughness of the cured product (coating film).

[0147] The number-average molecular weight (Mn) of the polyorganosilsesquioxane in this disclosure, measured by gel permeation chromatography on a standard polystyrene basis, is not particularly limited, but can be appropriately selected from, for example, a 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. Setting the number-average molecular weight to 1,000 or more tends to further improve the scratch resistance and toughness of the cured product (coating film). 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. Setting the number-average molecular weight to 50,000 or less (for example, 3,000 or less) tends to improve compatibility with other components in the hard coat agent, and further improve the scratch resistance and toughness of the cured product (coating film).

[0148] The molecular weight dispersibility (Mw / Mn) of the polyorganosilsesquioxane disclosed herein, measured by gel permeation chromatography on a standard polystyrene basis, is not particularly limited but can be appropriately selected from the range of 1.0 to 4.0. The lower limit of molecular weight dispersibility is preferably 1.0, more preferably 1.1, and even more preferably 1.2. Setting the molecular weight dispersibility to 1.1 or higher tends to make the hard coat agent more liquid and improve handling. On the other hand, the upper limit of molecular weight dispersibility is preferably 4.0, more preferably 3.0, and even more preferably 2.5. Setting the molecular weight dispersibility to 4.0 or lower tends to increase the scratch resistance and toughness of the cured product (coating film).

[0149] The number-average molecular weight and molecular weight dispersion of the polyorganosylsesquioxanes disclosed herein can be measured using the following apparatus and conditions. Measuring device: Product name "LC-20AD" (manufactured by Shimadzu Corporation) Columns: Shodex KF-801 x 2, KF-802, and KF-803 (manufactured by Showa Denko Corporation) Measurement temperature: 40℃ Eluent: THF, sample concentration 0.1~0.2% by mass Flow rate: 1mL / min Detector: UV-VIS detector (product name "SPD-20A", manufactured by Shimadzu Corporation) Molecular weight: on a standard polystyrene basis

[0150] The temperature at which the polyorganosilsesquioxanes of this disclosure lose 5% of their weight in an air atmosphere (T d5 The 5% weight loss temperature is not particularly limited, but is preferably 330°C or higher (for example, 330-450°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, the polyorganosilsesquioxane of this disclosure has a ratio [T3 / T2] of 5 to 500, a number-average molecular weight of 1000 to 50000, and a molecular weight dispersion of 1.0 to 4.0, thereby controlling its 5% weight loss temperature to 330°C or higher. The 5% weight loss temperature is the temperature at which 5% of the weight before heating is lost when heated at a constant heating rate, and serves as an indicator of heat resistance. The above 5% weight loss temperature can be measured by TGA (thermogravimetric analysis) under an air atmosphere and a heating rate of 5°C / min.

[0151] Furthermore, the silanol group content in the polyorganosilsesquioxane of this 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%. A silanol group content of 0.1% or more in the polyorganosilsesquioxane of this disclosure facilitates adhesion to the undercoat layer.

[0152] The polyorganosilsesquioxanes of this disclosure can be produced by known or conventional methods for producing polysiloxanes, and are not particularly limited, but for example, they can be produced by hydrolysis and condensation of one or more hydrolyzable silane compounds.

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

[0154] In the hard coat agent described above, one polyorganosilsesquioxane of the disclosed herein may be used alone, or two or more may be used. That is, the hard coat layer may contain one polyorganosilsesquioxane of the disclosed herein alone, or it may contain two or more.

[0155] The content (amount blended) 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, based on the total amount of the hard coat layer (total amount of hard coat agent excluding solvent; 100% by mass). By setting the content of the curable polyorganosilsesquioxane resin to 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 setting the content of the curable polyorganosilsesquioxane resin to less than 100% by mass, a curing agent can be included, and curing tends to proceed more efficiently.

[0156] The ratio of the polyorganosilsesquioxane of this disclosure to the total amount (100% by mass) of the photocationic curable compound and photoradical curable compound contained in the above hard coat 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 increasing the content of the photocationic curable compound and the photoradical curable compound to 70% by mass or more, the scratch resistance and toughness of the cured product (coating film) tend to be further improved. Note that if only one of the above photocationic curable compound and the above photoradical curable compound is contained, the ratio to the total amount is indicated.

[0157] The above hard coat agent preferably further contains a curing agent to promote the curing reaction by activation energy ray irradiation. In particular, it is especially preferable that the curing agent contains a photocationic polymerization initiator and / or a photoradical polymerization initiator, as this shortens the curing time until the surface becomes tack-free.

[0158] As the photocationic polymerization agent described above, the same agent as that disclosed in the curable composition described above can be used.

[0159] The above-mentioned photoradical polymerization initiator is a compound that can initiate or promote the photoradical polymerization reaction of photoradical-curable compounds such as polyorganosylsesquioxanes of this disclosure. Examples of the above-mentioned 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] Furthermore, in the hard coat agent described above, the hardening agent can be used alone or in combination of two or more types.

[0161] The content (amount) of the curing agent in the hard coat agent described above 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 of the polyorganosilsesquioxane of this disclosure and other active energy ray curable compounds described later (100 parts by mass; total amount of active energy ray curable compounds). By setting the curing agent content to 0.01 parts by mass or more, the curing reaction can be carried out efficiently and sufficiently, and the scratch resistance and toughness of the cured product (coating film) tend to be further improved. On the other hand, by setting the curing agent content to 5.0 parts by mass or less, the shelf life of the hard coat agent tends to be further improved and discoloration of the cured product (coating film) tends to be suppressed.

[0162] The hard coat agent described above may further contain active energy ray curable compounds other than the polyorganosilsesquioxanes of this disclosure (sometimes referred to as "other active energy ray curable compounds"). Examples of other active energy ray curable compounds include photocationic curable compounds other than the polyorganosilsesquioxanes of this disclosure (sometimes referred to as "other photocationic curable compounds") and / or photoradical curable compounds other than the polyorganosilsesquioxanes of this disclosure (sometimes referred to as "other photoradical curable compounds").

[0163] Other photocationically curable compounds can be known or conventionally used photocationically curable compounds, and are not particularly limited, but examples include epoxy compounds other than the polyorganosilsesquioxanes of this disclosure, oxetane compounds, vinyl ether compounds, etc. In the hard coat agent described above, one other photocationically curable compound may be used alone, or two or more may be used.

[0164] Examples of the epoxy compound and oxetane compound mentioned above include those similar to those described in the curable composition described above.

[0165] In the hard coating agent described above, it is preferable to use an epoxy compound as another photocationically curable compound in combination with the polyorganosilsesquioxane of this disclosure.

[0166] Other photoradical-curable compounds can be known or conventional photoradical-curable compounds, and are not particularly limited. Examples include compounds other than the polyorganosylsesquioxane disclosed herein that have one or more photoradical polymerizable groups in one molecule, such as (meth)acrylic groups, (meth)acryloxy groups, (meth)acrylamino groups, vinyl ether groups, vinylaryl groups, and vinyloxycarbonyl groups. In the hard coat agent described above, one or more of the other photoradical-curable compounds can be used individually or in combination of two or more.

[0167] If the above hard coat agent contains other active energy ray curable compounds, the content (amount blended) thereof is not particularly limited, but is preferably 3 to 50% by mass, more preferably 5 to 40% by mass, and even more preferably 7 to 30% by mass, relative to the total amount of the polyorganosilsesquioxane and other active energy ray curable compounds (100% by mass; total amount of active energy ray curable compounds) of the present disclosure. By setting the content of other active energy ray curable compounds to 50% by 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% by mass or more, it may be possible to impart desired performance (for example, rapid curing or viscosity adjustment for the hard coat agent) to the hard coat agent or the cured product (coating film).

[0168] The hard coat agent preferably contains a compound having one or more thermopolymerizable functional groups and one or more photopolymerizable functional groups in one molecule (hereinafter sometimes referred to as "compound A"). By including compound A together with the polyorganosilsesquioxane of this disclosure, the crosslinking density when cured can be effectively increased, making it easier to impart high surface hardness and excellent properties to the cured product (coating film).

[0169] The "thermally polymerizable functional group" of compound A is not particularly limited as long as it is a functional group that imparts polymerizability to compound A by heat, but examples include hydroxyl groups, epoxy groups, oxetanyl groups, vinyl ether groups, etc., and from the viewpoint of the surface hardness of the coating film of this disclosure, hydroxyl groups and epoxy groups are preferred. If compound A has two or more thermopolymerizable functional groups, these thermopolymerizable functional groups may be the same or different.

[0170] The "photopolymerizable functional group" of 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). Examples include (meth)acryloyl groups and vinyl groups, and from the viewpoint of the surface hardness of the coating film of this disclosure, (meth)acryloyl groups are preferred. If compound A has two or more photopolymerizable functional groups, these photopolymerizable functional groups may be the same or different.

[0171] The number of thermopolymerizable functional groups that compound A has in one molecule is not particularly limited, but is preferably 1 to 5, more preferably 1 to 3, and even more preferably 1 or 2. Similarly, the number of photopolymerizable functional groups that compound A has in one molecule is not particularly limited, but is preferably 1 to 5, more preferably 1 to 3, and even more preferably 1 or 2.

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

[0174] Compound A specifically includes, for example, 3,4-epoxycyclohexylmethyl (meth)acrylate, glycidyl (meth)acrylate, tripropylene glycol diglycidyl ether di(meth)acrylate (a compound obtained by reacting (meth)acrylic acid with both epoxy groups of tripropylene glycol diglycidyl ether), tripropylene glycol diglycidyl ether half(meth)acrylate (a compound obtained by reacting (meth)acrylic acid with one epoxy group of tripropylene glycol diglycidyl ether), and bis(4-3 Bisphenol A epoxy di(meth)acrylate (a compound obtained by reacting both epoxy groups of bisphenol A diglycidyl ether with (meth)acrylic acid), bisphenol A epoxy half(meth)acrylate (a compound obtained by reacting one epoxy group of bisphenol A diglycidyl ether with (meth)acrylic acid or 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 Compounds having an epoxy group and / or a hydroxyl group and a (meth)acryloyl group in one molecule, such as acrylate; compounds having an oxetanyl group and a (meth)acryloyl group in one molecule, such as 3-oxetanylmethyl (meth)acrylate, 3-methyl-3-oxetanylmethyl (meth)acrylate, 3-ethyl-3-oxetanylmethyl (meth)acrylate, 3-butyl-3-oxetanylmethyl (meth)acrylate, 3-hexyl-3-oxetanylmethyl (meth)acrylate; 2-vinyloxyethyl (meth)acrylate, 3-vinyloxyethyl (meth)acrylate Niloxypropyl, 1-methyl-2-vinyloxyethyl (meth)acrylate, 2-vinyloxypropyl (meth)acrylate, 4-vinyloxybutyl (meth)acrylate, 1-methyl-3-vinyloxypropyl (meth)acrylate, 1-vinyloxymethylpropyl (meth)acrylate, 2-methyl-3-vinyloxypropyl (meth)acrylate, 1,1-dimethyl-2-vinyloxyethyl (meth)acrylate, 3-vinyloxybutyl (meth)acrylate, 1-methyl-2-vinyloxypropyl (meth)acrylate, 2-vinyloxybutyl (meth)acrylate(meth)acrylate 4-vinyloxycyclohexyl, (meth)acrylate 6-vinyloxyhexyl, (meth)acrylate 4-vinyloxymethylcyclohexylmethyl, (meth)acrylate 3-vinyloxymethylcyclohexylmethyl, (meth)acrylate 2-vinyloxycyclohexylmethyl, (meth)acrylate p-vinyloxymethylphenylmethyl, (meth)acrylate m-vinyloxymethylphenylmethyl, (meth)acrylate o-vinyloxymethylphenylmethyl, (meth)acrylate 2-(vinyloxyethoxy)ethyl, (meth ) 2-(vinyloxyisopropoxy)ethyl acrylate, 2-(vinyloxyethoxy)propyl meth)acrylate, 2-(vinyloxyethoxy)isopropyl meth)acrylate, 2-(vinyloxyisopropoxy)propyl meth)acrylate, 2-(vinyloxyisopropoxy)isopropyl meth)acrylate, 2-(vinyloxyethoxyethoxy)ethyl meth)acrylate, 2-(vinyloxyethoxyisopropoxy)ethyl meth)acrylate, (meth)acrylate (Meth) 2-(vinyloxyisopropoxyisopropoxy)ethyl acrylate, (meth) 2-(vinyloxyethoxyethoxy)propyl acrylate, (meth) 2-(vinyloxyethoxyisopropoxy)propyl acrylate, (meth) 2-(vinyloxyisopropoxyethoxy)propyl acrylate, (meth) 2-(vinyloxyisopropoxyisopropoxy)propyl acrylate, (meth) 2-(vinyloxyethoxyethoxy)isopropyl acrylate, (meth) 2-(vinyloxyethoxyisopropoxy)isopropyl acrylate, (meth ) 2-(vinyloxyisopropoxyethoxy)isopropyl acrylate, 2-(vinyloxyisopropoxyisopropoxy)isopropyl meth)acrylate, 2-(vinyloxyethoxyethoxyethoxy)ethyl meth)acrylate, 2-(vinyloxyethoxyethoxyethoxyethoxy)ethyl meth)acrylate, 2-(isopropenoxyethoxy)ethyl meth)acrylate, 2-(isopropenoxyethoxyethoxy)ethyl meth)acrylate, 2-(isopropenoxyethoxyethoxyethoxy)ethyl meth)acrylate,Examples include compounds having a vinyl ether group and a (meth)acryloyl group in one molecule, such as 2-(isopropenoxyethoxyethoxyethoxyethoxy)ethyl (meth)acrylate, polyethylene glycol monovinyl ether (meth)acrylate, and polypropylene glycol monovinyl ether (meth)acrylate.

[0175] From the viewpoint of the cured product (coating film) and 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 within one molecule. Specifically, 3,4-epoxycyclohexylmethyl (meth)acrylate, glycidyl (meth)acrylate, tripropylene glycol diglycidyl ether half (meth)acrylate, bisphenol A epoxy half (meth)acrylate, bisphenol F epoxy half (meth)acrylate, bisphenol S epoxy half (meth)acrylate, etc., are preferred.

[0176] Furthermore, in the hard coat agent described above, compound A may be used alone or in combination of two or more types. Compound A can be produced by known methods, for example, by reacting a portion of the thermally polymerizable functional groups (e.g., epoxy groups, hydroxyl groups) of a compound having two or more thermally polymerizable functional groups in one molecule with a carboxylic acid (e.g., acrylic acid, methacrylic acid, etc.) or a derivative thereof having a photopolymerizable functional group.

[0177] The content (amount blended) of compound A in the above hard coat 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, per 100 parts by mass of the total amount of polyorganosilsesquioxane and other active energy ray curable compounds (total amount of active energy ray curable compounds) of the present disclosure. By increasing the content of compound A to 1 part by mass or more, the curing of the cured product (coating film) tends to be further improved. On the other hand, by keeping the content of compound A at 100 parts by mass or less, the surface hardness of the cured product (coating film) tends to be maintained.

[0178] The hard coat agent described above preferably contains a surface modifier. As the surface modifier, known or conventionally used compounds added for purposes such as defoaming, leveling, and preventing under-staining can be used. As the defoaming agent, leveling agent, and under-staining agent, for example, aqueous or non-aqueous compounds consisting of polymer main components such as butadiene, acrylic, and olefin, or silicone-based main components such as silicone and fluorine-modified silicone, can be used. Among these, it is preferable that the aqueous or non-aqueous compound consisting of a main component selected from the silicone-based main components includes a radical-curable polyorganosiloxane. Using the radical-curable polyorganosiloxane improves the smoothness of the hard coat layer surface, provides excellent resistance to sebum adhesion, and makes the surface less prone to fingerprints. Furthermore, it is preferable that the radical-curable polyorganosiloxane is not a compound that falls under the category of PFAS. In this case, it exhibits the above-mentioned effects while not being included in the category of PFAS compounds. Since the radical-curable polyorganosiloxane has radical curability, it also falls under the category of curable compounds. The above-mentioned radical-curable polyorganosiloxane may be used alone or in combination of two or more types.

[0179] The above-mentioned radical-curable polyorganosiloxane has a radical-polymerizable functional group within its molecule. Examples of such radical-curable functional groups include photo-radical polymerizable functional groups.

[0180] Examples of the above-mentioned photoradical polymerizable functional groups include (meth)acryloyl groups, (meth)acrylamide groups, vinyl groups, and vinylthio groups. Among these, (meth)acryloyl groups are preferred.

[0181] In the above-mentioned radical-curable polyorganosiloxane, linear polyorganosiloxanes are preferred as polyorganosiloxanes from the viewpoint of exhibiting greater effectiveness as leveling agents.

[0182] The content (amount) of the surface modifier in the hard coat agent described above is not particularly limited, but as solid content, it is, 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 polyorganosilsesquioxane and other active energy ray curable compounds (total amount of active energy ray curable compounds) of the polyorganosilsesquioxane and other active energy ray curable compounds of this disclosure. By increasing the content of the surface modifier to 0.01 parts by mass or more, the leveling properties of the cured product (coating film) tend to be further improved.

[0183] The hard coat agent described above preferably contains an antioxidant. The inclusion of an antioxidant in the hard coat agent tends to further improve the surface hardness of the cured product (coating film). Only one type of antioxidant may be used, or two or more types may be used.

[0184] As the antioxidant mentioned above, the same antioxidant as those exemplified in the photocurable compounds described above can be used.

[0185] If the above hard coat agent contains an antioxidant, its content (amount blended) is not particularly limited, but is preferably 0.05 to 5 parts by mass, and more preferably 0.1 to 3 parts by mass, relative to the total amount (100 parts by mass) of the active energy ray curable compound contained in the hard coat agent. If the antioxidant content 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, if the antioxidant content is 5 parts by mass or less, discoloration 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 this disclosure and any additives used as needed, and does not inhibit polymerization. One or more solvents may be used.

[0187] The solvent should preferably be one that can provide fluidity suitable for application to the hard coat layer and can be easily removed by heating at a temperature that suppresses the progression of polymerization. It is preferable to use one or more solvents with a boiling point (at 1 atm) of 170°C or lower (for example, aromatic solvents such as toluene, xylene, and mesitylene; esters such as butyl acetate; ketones such as methyl isobutyl ketone and cyclohexanone; ethers such as propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate).

[0188] The solvent should be used in a range where the concentration of non-volatile components in the hard coat 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 order to achieve excellent coatability. However, the amount added should be selected as the optimal amount to adjust the viscosity so that an appropriate film thickness can be achieved, and is not limited to the above range. In other words, if the amount of solvent used is excessive, the viscosity of the hard coat agent tends to become low, making it difficult to form a coating film of an appropriate thickness. On the other hand, if the amount of solvent used is too little, the viscosity of the hard coat agent tends to become too high, making it difficult to apply uniformly to the glass substitute substrate.

[0189] The above hard coat agent may also contain, as other optional components, inorganic fillers such as precipitated silica, wet silica, fumed silica, calcined silica, titanium dioxide, alumina, glass, quartz, aluminosilicate, iron oxide, zinc oxide, calcium carbonate, carbon black, silicon carbide, silicon nitride, and boron nitride; inorganic fillers obtained by treating these fillers with organosilicon compounds such as organohalosilane, organoalkoxysilane, and organosilazane; fine powders of organic resins such as silicone resin, epoxy resin, and fluororesin; fillers such as conductive metal powders such as silver and copper; curing aids; stabilizers (light stabilizers, heat stabilizers, heavy metal deactivators, etc.); and ultraviolet absorbers (triazine-based ultraviolet absorbers, benzotriazole). The product may contain conventional additives such as phosphorus-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 additives, reinforcing materials (other fillers, etc.), nucleating agents, coupling agents (silane coupling agents, etc.), lubricants, waxes, plasticizers, mold release agents, impact resistance modifiers, color modifiers, transparency modifiers, rheology modifiers (flow modifiers, etc.), processability modifiers, colorants (dyes, pigments, etc.), antistatic agents, dispersants, surface modifiers (slip agents, etc.), matting agents, defoaming agents, anti-foaming agents, antibacterial agents, preservatives, viscosity modifiers, thickeners, photosensitizers, and foaming agents. These additives may be used individually or in combination of two or more types.

[0190] Furthermore, it is preferable that the hard coat agent does not contain compounds that fall under the category of PFAS. In other words, it is preferable that the hard coat layer containing the hard coat agent does not contain compounds that fall under the category of PFAS. By having the above configuration, compounds that fall under the category of PFAS are not used, compliance with environmental regulations is achieved, and safety is superior.

[0191] The above hard coating agent is not particularly limited, but can be prepared by stirring and mixing each of the above components at room temperature or, if necessary, while heating. The above hard coating agent can be used as a one-component composition in which the components are pre-mixed, or it can be used as a multi-component (e.g., two-component) composition in which two or more components that have been stored separately are mixed in a predetermined ratio before use.

[0192] The hard coat agent described above is not particularly limited, but it is preferably a liquid at room temperature (approximately 25°C). More specifically, the viscosity of the hard coat agent diluted in 20% solvent [particularly a hard coat agent solution in which the proportion of methyl isobutyl ketone is 20% by mass] at 25°C is preferably 300 to 20000 mPa·s, more preferably 500 to 10000 mPa·s, and even more preferably 1000 to 8000 mPa·s. Setting the viscosity to 300 mPa·s or higher tends to improve the curing of the product (coating film). On the other hand, setting the viscosity to 20000 mPa·s or lower makes the preparation and handling of the hard coat agent easier, and tends to reduce the likelihood of air bubbles remaining in the cured product (coating film). The viscosity of the above hard coating agent is measured using a viscometer (product name "MCR301", manufactured by Anton Paar) under the following conditions: amplitude 5%, frequency 0.1-100 (1 / s), and temperature 25°C.

[0193] By applying and curing the prepared hard coat agent onto the undercoat layer in a known or conventional manner, a laminate having a three-layer structure of a substrate, an undercoat layer, and a hard coat layer can be produced.

[0194] The coating and curing method for the hard coat layer described above can be the same as that exemplified for the undercoat layer described above. When irradiating the hard coat layer with ultraviolet light, for example, the cumulative irradiation dose should be 1 to 5000 mJ / cm². 2 It is preferable to keep it to a certain extent.

[0195] The specific curing conditions are not particularly limited, but for example, the hard coat agent is first heat-treated (pre-baked) at a temperature of preferably 60°C or higher, more preferably 120°C or higher, even more preferably 150°C or higher, for preferably 10 seconds or more, more preferably 30 seconds or more, and even more preferably 60 seconds or more, and then irradiated with ultraviolet light (irradiation conditions (irradiation amount): preferably 300 mJ / cm²). 2 More than; Irradiation intensity: 100mW / cm 2 (As described above), finally, the product can be cured by heat treatment (aging) at a temperature of 120°C or higher, preferably for 0.5 hours or more. However, the curing conditions are not limited to this range, and the pre-bake temperature, time, and aging temperature can be appropriately selected depending on the solvent used, and the ultraviolet irradiation conditions can also be appropriately selected depending on the curing agent used.

[0196] As described above, the hard coat agent, when applied and cured, can form a hard coat layer with high scratch resistance, surface hardness, and toughness. The laminate thus produced has excellent adhesion while improving the surface hardness of the hard coat 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. A surface hardness of 0.5 μm or higher makes it easier to improve the surface hardness.

[0198] Preferably, the hard coat layer surface of the above laminate does not exhibit tackiness upon finger touch.

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

[0200] Furthermore, in accordance with JIS K5600-5-6, the laminate is scraped with a cutter blade at 1 mm intervals from the hard coat layer side to create 100 grid squares, which are then attached with adhesive tape. When peeled off in a 90° direction and visually inspected to see if the coating surface adheres to the adhesive tape before peeling, it is preferable that 90 or more squares remain, more preferably 95 or more, and particularly preferably 100. The remaining 90 or more squares on the laminate confirm that the hard coat layer and the undercoat layer exhibit sufficient adhesion.

[0201] [Display device] One embodiment of the present disclosure is a display device equipped with the above-mentioned laminate. In the above-mentioned display device, the laminate is arranged such that, for example, the hard coat layer constitutes the viewable surface. The above-mentioned display device is not particularly limited and includes, for example, organic EL display devices, inorganic EL display devices, liquid crystal display devices, etc. Because the surface of the hard coat layer of the above-mentioned display device has sufficient surface hardness, scratches are less likely to occur on the surface. Furthermore, the above-mentioned display device can also be used as a flexible display that can be bent or wound.

[0202] Each embodiment disclosed herein can be combined with any other features disclosed herein. Furthermore, each configuration and combination thereof in each embodiment is an example, and additions, omissions, and other modifications are permitted as appropriate, without departing from the spirit of this disclosure. This disclosure is not limited by the embodiments, but is limited only by the scope of the claims. [Examples]

[0203] An embodiment of this disclosure will be described in more detail below based on examples.

[0204] Manufacturing Example 1 (Manufacturing of polyorganosilsesquioxane) A 1000 ml flask (reaction vessel) equipped with a thermometer, stirrer, reflux condenser, and nitrogen inlet tube was charged with 277.2 mmol (68.30 g) of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3.0 mmol (0.56 g) of phenyltrimethoxysilane, and 275.4 g of acetone under a nitrogen stream, and the temperature was raised to 50°C. To the mixture obtained in this way, 7.74 g of 5% potassium carbonate aqueous solution (2.8 mmol as potassium carbonate) was added over 5 minutes, and then 2800.0 mmol (50.40 g) of water was added over 20 minutes. No significant temperature increase occurred during the addition. Subsequently, the polycondensation reaction was carried out at 50°C under a nitrogen stream for 5 hours. Subsequently, while the reaction solution was cooled, 137.70 g of methyl isobutyl ketone and 100.60 g of 5% saline solution were added. This solution was transferred to a 1 L separatory funnel, and another 137.70 g of methyl isobutyl ketone was added, followed by washing with water. After separation, the aqueous layer was removed, and the lower layer was washed with water until it became neutral. The upper layer was then separated, and the solvent was removed from the upper layer under conditions of 1 mmHg and 50°C to obtain 75.18 g of a colorless, transparent, liquid product (epoxy group-containing low molecular weight polyorganosilsesquioxane: silsesquioxane from Production Example 1) containing 23% by mass of methyl isobutyl ketone. Furthermore, analysis of the product revealed that the number-average molecular weight was 2235 and the molecular weight dispersion was 1.54. 29 The ratio of T2 to T3 isomers [T3 / T2] calculated from the Si-NMR spectrum was 11.9. 1 H-NMR, 29 Confirmation was performed using Si-NMR. The molecular weight of the product was measured using a Shimadzu LC-20AD pump, Shodex RI-504 detector, Shodex GPC KF-602 and KF-603 columns, Shodex GPC KF-G guard column, THF solvent, and at 40°C. The ratio of T2 to T3 isomers [T3 / T2] in the product was measured using a JEOL ECA500 (500MHz). 29The measurement was performed using Si-NMR spectroscopy.

[0205] (Preparation of hard coat agent) A hard coat agent was prepared by mixing the silsesquioxane from Production Example 1 with the materials in the proportions shown in Table 1. The percentages shown in Table 1 represent the blending ratio of each component. For silsesquioxane (77% by mass of active ingredient) and RS-57 (20% by mass of active ingredient) from Production Example 1, these are the values ​​for the solution, while the values ​​for the other components represent the active ingredient values.

[0206] [Table 1]

[0207] The components used in Table 1 are described in detail below. 200PA-E5: Product name "Epoxy Ester 200PA-E5", manufactured by Kyoeisha Chemical Co., Ltd. (A compound having one or more thermopolymerizable functional groups and one or more photopolymerizable functional groups in one molecule) Epolite 1600N: Product name "Epolite 1600N" Manufactured by Kyoeisha Chemical Co., Ltd. (Other photocationic curable compounds) RS-57: Product name "Megafac RS-57", manufactured by DIC Corporation (surface conditioning agent) Omnirad127: Product name "Omnirad127", manufactured by IGM Resins BV (photoradical polymerization initiator) CPI-310FG: Product name "CPI-310FG", manufactured by Sunapro Co., Ltd. (Photocationic polymerization initiator) ADEKA Stab AO-02: Product name "ADEKA Stab AO-02", manufactured by ADEKA Corporation (antioxidant) MIBK: Methyl isobutyl ketone (solvent) MEK: Methyl ethyl ketone (solvent)

[0208] Examples 1-6, Comparative Examples 1-5 A mixed solution was prepared with the proportions shown in Table 2 and used as the curable composition. The curable composition obtained above was coated onto the surface of a glass substrate (glass slide) using a wire bar #12 so that the thickness after curing was 10 μm, and then cured using an LED lamp at 3000 mJ / cm². 2 The sample was irradiated with ultraviolet light at a specified intensity. An undercoat layer was then created by heat treatment in a 150°C oven for 30 minutes.

[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 2 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 "Compocelan SQ502-8", manufactured by Arakawa Chemical Industries, Ltd. (a polyorganosiloxane containing silanol groups with a T1 content of 25%, a T2 content of 63%, and a T3 content of 12%). E103-D: Product name "Compocelan E103-D", manufactured by Arakawa Chemical Industries, Ltd. (polyorganosiloxane containing silanol groups) CPI-101A: Product name "CPI-101A", manufactured by Sunapro Co., Ltd. (photopolymerization initiator) CPI-100P: Product name "CPI-100P", manufactured by Sunapro Co., Ltd. (photopolymerization initiator) PEP-36: Product 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] On the above undercoat layer, the hard coat agent prepared in Production Example 1 was further applied using a wire bar #24 so that the thickness of the cured hard coat layer would be 20 μm, and then left in an oven at 80°C for 1 minute and in an oven at 120°C for 2 minutes. Next, ultraviolet rays were irradiated using a high-pressure mercury lamp at an illuminance of 300 mJ / cm 2 . Thereafter, the hard coat agent was cured by heat treatment in an oven at 120°C for 60 minutes to prepare the laminates of Examples 1 to 6 and Comparative Examples 1 to 5.

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

[0212] (1) Tackiness after curing The surface of the laminates of Examples 1 to 6 and Comparative Examples 1 to 5 was checked for tackiness by finger touch. When there was tackiness, it was marked as △, and when there was no tackiness, it was marked as 〇.

[0213] (2) Adhesion test According to JIS K5600-5-6, the surface of the hard coat layer of the laminates of Examples 1 to 6 and Comparative Examples 1 to 5 was scratched with a cutter blade at an interval of 1 mm to create 100 grids, pasted with an adhesive tape, peeled off in the 90° direction, and visually checked whether the surface of the coating peeled off after sticking to the adhesive tape. When 100 were adhered, it was marked as ◎, when 90 or more were adhered, it was marked as 〇, and when less than 90 were adhered, it was marked as ×.

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

[0215]

Table 2

[0216] As shown in Table 2, the curable composition of this disclosure exhibits sufficient adhesion and excellent surface hardness when it contains 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 oxetane compound (Examples 1-6). On the other hand, when the polyorganosiloxane having a silanol group was not included, the adhesion was poor (Comparative Examples 1, 2), and when the composition was changed to improve adhesion without including the polyorganosiloxane having a silanol group, the surface hardness was poor (Comparative Examples 3-5).

[0217] The following describes variations of the invention relating to this disclosure. [Note 1] A curable composition comprising 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 oxetane compound. [Note 2] The curable composition according to Appendix 1, comprising the first epoxy compound, the second epoxy compound, the polyorganosiloxane having a silanol group, and the oxetane compound. [Note 3] The curable composition according to Appendix 1 or 2, wherein the content of the first epoxy compound is 30 to 70% by mass relative to the total amount of the curable compound. [Note 4] The curable composition according to any one of the appendices 1 to 3, wherein the content of the second epoxy compound is 20 to 60% by mass relative to the total amount of the curable compound. [Note 5] The curable composition according to any one of the appendices 1 to 4, wherein the content of the oxetane compound is 5 to 25% by mass relative to the total amount of the curable compound. [Note 6] The curable composition according to any one of the appendices 1 to 5, wherein the content of the polyorganosiloxane having the silanol group is 1 to 15% by mass relative to the total amount of the curable compound. [Note 7] A curable composition as described in any one of the appendices 1 to 6, which does not contain hazardous substances. [Note 8] A curable composition according to any one of the appendices 1 to 7, which does not contain any compounds that fall under the category of PFAS. [Note 9] An undercoat layer containing a cured product of a curable composition described in any one of the appendices 1 to 8. [Note 10] The undercoat layer described in Appendix 9, having a thickness of 0.1 to 20 μm. [Note 11] A laminate comprising a base material, an undercoat layer according to appendix 9 or 10 formed on at least one surface of the base material, and a hardcoat layer, laminated in this order. [Note 12] The laminate according to Appendix 11, wherein the substrate is a glass substrate. [Note 13] The laminate according to Appendix 11 or 12, wherein the hard coat layer comprises a curable polyorganosilsesquioxane resin as the curable resin. [Note 14] The laminate according to any one of the appendices 11 to 13, wherein the pencil hardness of the surface of the hard coat layer is 3H or higher. [Note 15] The laminate according to any one of the appendices 11 to 14, wherein 100 grid squares are created on the surface of the hard coat layer at 1 mm intervals, adhesive tape is applied, and when peeled off in a 90° direction, 90 or more squares remain. [Note 16] The laminate according to any one of appendices 11 to 15, wherein the hard coat layer does not contain a compound corresponding to PFAS. [Note 17] A display device comprising a laminate as described in any one of appendices 11 to 16.

Claims

1. A curable composition comprising 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 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% by mass relative to the total amount of the curable compound.

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

5. The curable composition according to claim 1 or 2, wherein the content of the oxetane compound is 5 to 25% by mass relative to the total amount of the curable compound.

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

7. A curable composition according to claim 1 or 2, which does not contain a hazardous substance.

8. A curable composition according to claim 1 or 2, which does not contain a compound corresponding to PFAS.

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

10. The undercoat layer according to claim 9, wherein the thickness is 0.1 to 20 μm.

11. A laminate comprising a base material, an undercoat layer according to claim 9 formed on at least one surface of the base material, and a hardcoat 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 comprises a curable polyorganosilsesquioxane resin as a curable resin.

14. The laminate according to claim 11, wherein the pencil hardness of the surface of the hard coat layer is 3H or higher.

15. The laminate according to claim 11, wherein 100 grid squares are created on the surface of the hard coat layer at 1 mm intervals, and when adhesive tape is applied 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 a compound corresponding to PFAS.

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

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