Photocurable composition, undercoat layer, laminate, and display device

Abstract

The purpose of the present invention is to provide a photocurable composition which is excellent in terms of adhesion to a substrate and is easy to apply. The photocurable composition of the present disclosure includes a first epoxy compound that is an organosiloxane having at least two cycloaliphatic epoxy groups, a second epoxy compound, and a third epoxy compound and / or an oxetane compound, the first epoxy compound has a content of 30% to 70% by mass with respect to the total amount of the composition that does not include the solvent. The photocurable composition preferably includes the first epoxy compound, the second epoxy compound, and the oxetane compound.

Description

Technical Field

[0001] The present disclosure relates to a photocurable composition, a primer layer composed of a cured product thereof, a laminate, and an optical device. This application claims priority to Japanese Patent Application No. 2022-202436 filed in Japan on December 19, 2022, the contents of which are hereby incorporated herein by reference. Background Art

[0002] It is known that a hard coating layer is provided on the surface of an article (substrate) in which transparency and appearance are important (such as displays of televisions, computers, smartphones, etc., and films for such displays) for the purpose of improving scratch resistance (in other words, the property of preventing damage due to abrasion and scratching).

[0003] In particular, when a glass substrate is used as a substrate, in order to improve the adhesion between the hard coating layer and the glass substrate, a method of using a silane coupling agent on the surface of the glass substrate, a method of modifying the glass surface, etc. are known (for example, Non-Patent Document 1).

[0004] Citation List

[0005] Non-patent literature

[0006] Non-patent document 1: SUZUKI, Susumu, "Adhesion of Glass Coatings". Journal of the Surface Finishing Society of Japan, Vol. 48, No. 7, 1997, pp. 698-702 Summary of the invention

[0007] Technical issues

[0008] However, conventional methods of treating substrates may still be insufficient in terms of adhesion to the substrate.

[0009] In addition, it is known to provide a primer layer (interlayer adhesive layer) between the substrate and the hard coating layer in order to develop adhesion between the substrate and the hard coating layer. However, there is a problem that the primer layer cannot be applied well in conformity with the substrate, resulting in shrinkage. Therefore, the type of substrate may be limited, or a special application method may be required to apply the primer layer.

[0010] The present disclosure solves the above problems, and an object thereof is to provide a photocurable composition which is excellent in adhesion to a substrate and is easily applied.

[0011] Solution to the problem

[0012] The inventors of the present disclosure have found that a photocurable composition including the following is excellent in adhesion to a substrate and easy to apply: a first epoxy compound (which is an organosiloxane having at least two alicyclic epoxy groups), a second epoxy compound, and a third epoxy compound or an oxetane compound, the first epoxy compound having a content of 30% to 70% by mass based on the total amount of the curable compounds. The present disclosure has been completed based on these findings.

[0013] In other words, the present disclosure provides a photocurable composition including a first epoxy compound (which is an organosiloxane having at least two alicyclic epoxy groups), a second epoxy compound, and a third epoxy compound or an oxetane compound, the first epoxy compound having a content of 30% to 70% by mass based on the total amount of the composition excluding solvent.

[0014] In the case of the above configuration, the present disclosure has excellent adhesion to a substrate, can be easily applied, and can also have excellent scratch resistance when laminating a hard coat.

[0015] The photocurable composition of the present disclosure preferably includes the first epoxy compound, the second epoxy compound, and the oxetane compound mentioned above. In the case of the above configuration, the adhesion to a substrate, the applicability, and the scratch resistance (when laminating a hard coat) tend to be better.

[0016] The second epoxy compound preferably has a content of 20% to 60% by mass based on the total amount of the curable compounds. In the case of the above configuration, it tends to be easier to apply to a substrate.

[0017] The oxetane compound preferably has a content of 5% to 25% by mass based on the total amount of the curable compounds. In the case of the above configuration, the adhesion to a substrate tends to be better.

[0018] The present disclosure also provides a primer coat, which is a cured product of the photocurable composition.

[0019] The thickness of the primer coat is preferably 0.1 to 15 μm.

[0020] The present disclosure also provides a laminate including: a substrate, a primer coat formed on at least one surface of the substrate, and a hard coat laminated in this order.

[0021] The laminate preferably has a glass substrate as the substrate.

[0022] For the above laminate, preferably, the above hard coat contains a curable polyorganosilsesquioxane resin as the curable resin.

[0023] For the above laminate, preferably, the surface of the hard coat has a pencil hardness of 6H or more. In the case of the above configuration, the laminate tends to have sufficient surface hardness and excellent scratch resistance.

[0024] Preferably, in the laminate, 100 squares are formed in a grid pattern at 1 mm intervals on the surface of the hard coat, a tape is attached thereto, and after the tape is peeled off in the 90° direction, at least 90 squares remain. In the case of the above configuration, the undercoat and the hard coat can exhibit sufficient adhesion in the laminate.

[0025] The present disclosure also provides a display device provided with the above laminate.

[0026] Advantageous Effects of the Invention

[0027] The photocurable composition is excellent in adhesion to a substrate and is easy to apply. Further, in a laminate in which a hard coat layer is laminated on an undercoat layer formed of the above photocurable composition, the undercoat layer and the hard coat layer exhibit excellent adhesion, and at the same time, sufficient surface hardness can be imparted to the surface of the hard coat layer, resulting in excellent scratch resistance. Detailed Description

[0028] In the present specification, the term “(meth)acryloyl” means acryloyl and / or methacryloyl. The term “(meth)acrylate” means acrylate and / or methacrylate.

[0029] [Photocurable Composition]

[0030] The photocurable composition of the present disclosure includes a first epoxy compound (which is an organosiloxane having at least two alicyclic epoxy groups), a second epoxy compound, and a third epoxy compound or an oxetane compound, and the first epoxy compound has a content of 30% to 70% by mass based on the total amount of the curable compounds.

[0031] <Organosiloxane Having at Least Two Alicyclic Epoxy Groups (First Epoxy Compound)>

[0032] The photocurable composition contains a first epoxy compound, which is a silicone oxide having at least two alicyclic epoxy groups as described above. The first epoxy compound is a compound having at least two alicyclic epoxy groups in the molecule and further having at least a silicone oxide skeleton composed of silicone-oxygen bonds (Si-O-Si). The above-mentioned silicone oxide skeleton includes cyclic silicone oxide skeletons, linear or branched silicones (linear or branched polysiloxanes), cage-shaped and ladder-shaped polysilsesquioxanes, etc. In the present disclosure, among them, a compound having a cyclic silicone oxide skeleton is preferred because both easy applicability and adhesion to the substrate can be achieved. The first epoxy compound can be used alone or in combination of two or more.

[0033] When the first epoxy compound is a cyclic silicone oxide, the number of Si-O units forming the silicone oxide ring (equal to the number of silicon atoms forming the silicone oxide ring) is preferably 2 to 12 and more preferably 4 to 8.

[0034] The alicyclic epoxy group of the first epoxy compound means a cyclic olefin group epoxidized in the molecule. "Epoxidized cyclic olefin group" means a group (monovalent group) formed by removing one hydrogen atom from a structure in which at least one of the carbon-carbon bonds forming a ring in 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) is epoxidized. That is, the epoxidized cyclic olefin group includes a group having an aliphatic hydrocarbon ring structure and an epoxy group, wherein the epoxy group is composed of two adjacent carbon atoms and an oxygen atom constituting the aliphatic hydrocarbon ring.

[0035] Examples of the cyclic olefin group (in the form before epoxidation) in the epoxidized cyclic olefin group may include cycloalkenyl groups such as cyclopropenyl (e.g., 2-cyclopropen-1-yl, etc.), cyclobutenyl (e.g., 2-cyclobuten-1-yl, etc.), cyclopentenyl (e.g., 2-cyclopenten-1-yl, 3-cyclopenten-1-yl, etc.), and cyclohexenyl (e.g., 2-cyclohexen-1-yl, 3-cyclohexen-1-yl, etc.); cyclodienyl groups such as 2,4-cyclopentadien-1-yl, 2,4-cyclohexadien-1-yl, and 2,5-cyclohexadien-1-yl; polycyclic groups such as dicyclopentenyl, dicyclohexenyl, and norbornenyl; etc.

[0036] At least one substituent may be bonded to the aliphatic hydrocarbon ring forming the cyclic olefin group in the above epoxidized cyclic olefin group. As the above-mentioned substituent, for example, a substituent having 0 to 20 carbon atoms (more preferably a substituent having 0 to 10 carbon atoms), etc., and more specific examples thereof may include halogen atoms such as fluorine atom, chlorine atom, bromine atom, and iodine atom; hydroxyl group; alkoxy group (preferably C 1-6 alkoxy group and more preferably C 1-4alkoxy groups), such as methoxy, ethoxy, propoxy, isopropoxy, butoxy and isobutoxy; alkenyloxy groups (preferably C 2-6 alkenyloxy groups and more preferably C 2-4 alkenyloxy groups), such as allyloxy; aryloxy groups (preferably C 6-14 aryloxy groups), which may have substituents such as C 1-4 alkyl, C 2-4 alkenyl, halogen atoms, or C 1-4 alkoxy on an aromatic ring such as phenoxy, tolyloxy, or naphthyloxy; aralkyloxy groups (preferably C 7-18 aralkyloxy groups), such as benzyloxy and phenethyloxy; acyloxy groups (preferably C 1-12 acyloxy groups), such as acetoxy, propionyloxy, (meth)acryloxy and benzoyloxy; mercapto; alkylthio groups (preferably C 1-6 alkylthio groups and more preferably C 1-4 alkylthio groups), such as methylthio or ethylthio; alkenylthio groups (preferably C 2-6 alkenylthio groups and more preferably C 2-4 alkenylthio groups), such as allylthio; arylthio groups (preferably C 6-14 arylthio groups), which may have substituents such as C 1-4 alkyl, C 2-4 alkenyl, halogen atoms, or C 1-4 alkoxy on an aromatic ring such as phenylthio, tolylthio, or naphthylthio; aralkylthio groups (preferably C 7-18 aralkylthio groups), such as benzylthio or phenethylthio; carboxyl; alkoxycarbonyl groups (preferably C 1-6 alkoxycarbonyl groups), such as methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl and butoxycarbonyl; aryloxycarbonyl groups (preferably C 6-14 aryloxycarbonyl groups), such as phenoxycarbonyl, tolyloxycarbonyl and naphthyloxycarbonyl; aralkyloxycarbonyl groups (preferably C 7-18 aralkyloxycarbonyl groups), such as benzyloxycarbonyl; amino; mono- or di-alkylamino groups (preferably mono- or di-C 1-6 alkylamino groups), such as methylamino, ethylamino, dimethylamino and diethylamino; and acylamino groups (preferably C 1-11 acylamino groups), such as acetylamino, propionylamino and benzoylamino; groups containing an oxetanyl ring, such as ethyloxetanyloxy; acyl groups, such as acetyl, propionyl and benzoyl; oxo groups; groups in which two or more of these are optionally linked together via C 1-6 alkylene; etc.

[0037] Among them, the cyclic olefin group is preferably a cyclic olefin group having any one of 5 to 12 carbon atoms, more preferably a cycloalkenyl group having any one of 5 to 12 carbon atoms, and still more preferably a cyclohexenyl group. In other words, the epoxidized cyclic olefin group mentioned above is preferably a group formed by epoxidizing a cyclic olefin group having any one of 5 to 12 carbon atoms, more preferably a group formed by epoxidizing a cycloalkenyl group having any one of 5 to 12 carbon atoms, and still more preferably a group formed by epoxidizing a cyclohexenyl group (epoxycyclohexyl group). The first epoxy compound may have one kind of epoxidized cyclic olefin group or two or more thereof.

[0038] The number of epoxidized cyclic olefin groups in the first epoxy compound in the molecule is not particularly limited as long as it is at least 2 and preferably 2 to 6, more preferably 3 to 5, and still more preferably 4.

[0039] Examples of the first epoxy compound may include 2,4-bis[2-(3-{oxabicyclo[4.1.0]heptyl})ethyl]-2,4,6,6,8,8-hexamethyl-cyclotetrasiloxane, 4,8-bis[2-(3-{oxabicyclo[4.1.0]heptyl})ethyl]-2,2,4,6,6,8-hexamethyl-cyclotetrasiloxane, 2,4-bis[2-(3-{oxabicyclo[4.1.0]heptyl})ethyl]-6,8-dipropyl-2,4,6,8-tetramethyl-cyclotetrasiloxane, 4,8-bis[2-(3-{oxabicyclo[4.1.0]heptyl})ethyl]-2,6-dipropyl-2,4,6,8-tetramethyl-cyclotetrasiloxane, 2,4,8-tris[2-(3-{oxabicyclo[4.1.0]heptyl})ethyl]-2,4,6,6,8-pentamethyl-cyclotetrasiloxane, 2,4,8-tris[2-(3-{oxabicyclo[4.1.0]heptyl})ethyl]-6-propyl-2,4,6,8-tetramethyl-cyclotetrasiloxane, 2,4,6,8-tetrakis[2-(3-{oxabicyclo[4.1.0]heptyl})ethyl]-2,4,6,8-tetramethyl-cyclotetrasiloxane, a silsesquioxane having an epoxy group, and the like.

[0040] The content of the first epoxy compound in the photocurable composition of the present disclosure is preferably 30% to 70% by mass, more preferably 35% to 65% by mass, and still more preferably 40% to 60% by mass based on the total amount of the curable compounds. When the content is within the above range, the photocurable composition can be easily applied to the substrate, and the coated substrate has excellent adhesion.

[0041] <Second Epoxy Compound>

[0042] The photocurable composition contains an epoxide other than the first epoxide (hereinafter, the other epoxide is referred to as the "second epoxide"). By including the above second epoxide, the photocurable composition can be easily applied to a substrate.

[0043] Examples of the second epoxide may include alicyclic epoxides, aliphatic epoxides, aromatic epoxides, etc., other than the first epoxide described above. From the viewpoint of exhibiting applicability to a substrate in combination with the first epoxide, the second epoxide is preferably an alicyclic epoxide.

[0044] As other alicyclic epoxides, for example, compounds represented by the following formula (a1) may be mentioned.

[0045] [C1]

[0046]

[0047] In the above formula (a1), R is the same as the epoxidized cycloolefin group described above. Two Rs may be the same or different from each other. X represents a single bond or a linking group (a divalent group having at least one atom; a group not including a group containing a siloxane bond). Examples of the linking group may include a divalent hydrocarbon group, a carbonyl group, an ether bond, an ester bond, a carbonate group, an amide group, a group in which a plurality of these are linked, etc. Examples of the divalent hydrocarbon group may include a divalent aliphatic hydrocarbon group, a divalent alicyclic hydrocarbon group, and a group in which a plurality of these are bonded, etc. Examples of the divalent aliphatic hydrocarbon group may include a linear or branched alkylene group (for example, an alkylene group having 1 to 6 carbon atoms), such as a methylene group, a methylmethylene group, a dimethylmethylene group, an ethylene group, a propylene group, a trimethylene group, and a tetramethylene group, etc. Examples of the divalent alicyclic hydrocarbon group may include a divalent cycloalkylene group, such as a 1,2-cyclopentylene group, a 1,3-cyclopentylene group, a 1,2-cyclohexylene group, a 1,3-cyclohexylene group, and a 1,4-cyclohexylene group, etc. Examples of the compound represented by the formula (a1) may include a compound in which both Rs are epoxycyclohexyl groups (particularly, a compound in which the carbon atoms at the 4-position of the two epoxycyclohexyl groups (the positions of the two carbon atoms forming the epoxy group are defined as the 1-position and the 2-position) are connected by a single bond or via a divalent hydrocarbon group, etc.).

[0048] Specific examples of the alicyclic epoxy compound represented by the above formula (a1) may include (3,4,3’,4’-diepoxy)bicyclohexane, bis(3,4-epoxycyclohexylmethyl) ether, 1,2-epoxy-1,2-bis(3,4-epoxycyclohex-1-yl)ethane, 2,2-bis(3,4-epoxycyclohex-1-yl)propane, 1,2-bis(3,4-epoxycyclohex-1-yl)ethane, bis(3,4-epoxycyclohexylmethyl) ether, 3’,4’-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, and the like.

[0049] Other alicyclic epoxy compounds mentioned above further include compounds having an epoxy group directly bonded to the alicyclic ring through a single bond, hydrogenated aromatic glycidyl ether-based epoxy compounds, and the like, such as the compound represented by formula (b1).

[0050] [C2]

[0051]

[0052] In formula (b1), R i is a group obtained by removing q -OH groups from a q-valent alcohol, and p and q each represent natural numbers. Examples of the q-valent alcohol [R i -(OH)q] may include polyhydric alcohols (alcohols having 1 to 15 carbon atoms), such as 2,2-bis(hydroxymethyl)-1-butanol and the like. q is preferably 1 to 6, and p is preferably 1 to 30. When q is at least 2, p in at least two of the groups in parentheses (round parentheses) may be the same or different. Specific examples of the above compounds may include the 1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol, the product name "EHPE3150" (manufactured by Daicel Corporation), and the like.

[0053] Examples of hydrogenated aromatic glycidyl ether-based epoxy compounds may include hydrogenated compounds of bisphenol A epoxy compounds (hydrogenated bisphenol A epoxy compounds), such as 2,2-bis[4-(2,3-epoxypropoxy)cyclohexyl]propane, 2,2-bis[3,5-dimethyl-4-(2,3-epoxypropoxy)cyclohexyl]propane, and their polymers; hydrogenated compounds of bisphenol F epoxy compounds (hydrogenated bisphenol F epoxy compounds), such as bis[o,o-(2,3-epoxypropoxy)cyclohexyl]methane, bis[o,p-(2,3-epoxypropoxy)cyclohexyl]methane, bis[p,p-(2,3-epoxypropoxy)cyclohexyl]methane, bis[3,5-dimethyl-4-(2,3-epoxypropoxy)cyclohexyl]methane, and their polymers; hydrogenated bisphenol epoxy compounds; hydrogenated phenol novolac epoxy compounds; hydrogenated cresol novolac epoxy compounds; bisphenol A hydrogenated cresol novolac epoxy compounds; hydrogenated naphthalene epoxy compounds; hydrogenated epoxy compounds of epoxy compounds obtained from triphenol methane, etc.

[0054] Examples of aliphatic epoxy compounds may include glycidyl ethers of q-valent (q is a natural number) alcohols without a ring structure; glycidyl esters of monovalent or polyvalent carboxylic acids [e.g., acetic acid, propionic acid, butyric acid, stearic acid, adipic acid, sebacic acid, maleic acid, itaconic acid, etc.]; epoxidized materials of fats and oils having double bonds, such as epoxidized linseed oil, epoxidized soybean oil, and epoxidized castor oil; epoxidized materials of polyolefins (including polydienes), such as epoxidized polybutadiene; etc.

[0055] Examples of q-valent alcohols without a ring structure may include monovalent alcohols, such as methanol, ethanol, 1-propanol, isopropanol, and 1-butanol; divalent alcohols, such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, polyethylene glycol, and polypropylene glycol; polyvalent alcohols with a valence of three or more, such as glycerol, diglycerol, erythritol, trimethylolethane, trimethylolpropane, pentaerythritol, dipentaerythritol, and sorbitol; etc. Examples of q-valent alcohols may include polyether polyols, polyester polyols, polycarbonate polyols, polyolefin polyols, etc.

[0056] Examples of the aromatic epoxy compound may include bisphenol type glycidyl ether epoxy resins obtained by a condensation reaction between bisphenols [e.g., bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, etc.] and epihalohydrins; high molecular weight bisphenol type glycidyl ether epoxy resins obtained by a further addition reaction between these bisphenol type glycidyl ether epoxy resins and the above bisphenols; novolak alkyl type glycidyl ether epoxy resins obtained by a condensation reaction of phenols [e.g., phenol, cresol, xylenol, resorcinol, catechol, bisphenol A, bisphenol F, bisphenol S, etc.] and aldehydes [e.g., formaldehyde, acetaldehyde, benzaldehyde, hydroxybenzaldehyde, salicylaldehyde, etc.] to produce polyols, followed by a condensation reaction with epihalohydrins; epoxy compounds in which two phenol skeletons are bonded to the 9-position of a fluorene ring and glycidyl groups are directly or via an alkyleneoxy group bonded to the oxygen atom that removes a hydrogen atom from the hydroxyl group of these phenol skeletons; etc.

[0057] The content of the second epoxy compound in the photocurable composition of the present disclosure is preferably 20% to 60% by mass, more preferably 25% to 55% by mass, and still more preferably 30% to 50% by mass based on the total amount of the curable compounds. When the content is within the above range, the photocurable composition can be easily applied to a substrate.

[0058] <Oxetane compound>

[0059] As an example in the photocurable composition of the present disclosure, the photocurable composition contains an oxetane compound in addition to the first epoxy compound and the second epoxy compound. The oxetane compound is a compound having at least one oxetanyl group as a cationically polymerizable group in one molecule, and may be a compound having at least two oxetanyl groups. The oxetane compounds may be used alone or in combination of two or more. The inclusion of the above oxetane compound tends to enable the photocurable composition to exhibit good adhesion to a substrate.

[0060] Examples of the above oxetane compounds may include trimethylene oxide, 3,3-bis(vinyloxymethyl)oxetane, 3-ethyl-3-hydroxymethyloxetane, 3-ethyl-3-(2-ethylhexoxymethyl)oxetane, 3-ethyl-3-(hydroxymethyl)oxetane, 3-ethyl-3-[(phenoxy)methyl]oxetane, 3-ethyl-3-(hexyloxymethyl)oxetane, 3-ethyl-3-(chloromethyl)oxetane, 3,3-bis(chloromethyl)oxetane, 1,4-bis[(3-ethyl-3-oxetanylmethoxy)methyl]benzene, bis([1-ethyl(3-oxetanyl)methyl) ether, 4,4'-bis[(3-ethyl-3-oxetanyl)methoxymethyl]bicyclohexane, 1,4-bis[(3-ethyl-3-oxetanyl)methoxymethyl]cyclohexane, 3-ethyl-ethyl(3-ethyloxetane-3-yl)methoxy]methyl}oxetane, and the like.

[0061] The content of the oxetane compound is preferably 5% to 25% by mass, more preferably 10% to 20% by mass, relative to the total amount of the curable compound. The content of the oxetane compound within the above range makes it easier to exhibit adhesion to the substrate.

[0062] In addition to the above oxetane compounds, the photocurable composition may further contain a third epoxy compound and a fourth epoxy compound, which will be described later.

[0063] <Third epoxy compound>

[0064] As another example of the photocurable composition of the present disclosure, in addition to the first epoxy compound and the second epoxy compound described above, it is preferable to include a third epoxy compound that does not correspond to the above first epoxy compound and is different from the above second epoxy compound. In the above photocurable composition, the epoxy compound having a higher content is referred to as the second epoxy compound, and the epoxy compound having a lower content is referred to as the third epoxy compound.

[0065] Examples of the above third epoxy compound may include epoxy compounds other than those used as the second epoxy compound among the epoxy compounds not classified as the first epoxy compound, and specific examples may include those exemplified as the above second epoxy compound.

[0066] In particular, as the above third epoxy compound, when an alicyclic epoxy compound is included as the second epoxy compound, it is preferable to include an aliphatic epoxy compound as the third epoxy compound. Including the above aliphatic epoxy compound as the third epoxy compound makes it easier to exhibit adhesion to the substrate. As the aliphatic epoxy compound, those exemplified as the aliphatic epoxy compounds for the above second epoxy compound can be used.

[0067] When the third epoxy compound is included, the content of the third epoxy compound content is preferably 5% to 25% by mass, more preferably 7% to 20% by mass, relative to the total amount of the curable compound. The content of the third epoxy compound within the above range makes it easier to exhibit adhesion to the substrate.

[0068] The above photocurable composition may further contain an epoxy compound (hereinafter referred to as "fourth epoxy compound") other than the above first to third epoxy compounds. As the above fourth epoxy compound, an epoxy compound other than those used as the second and third epoxy compounds among the epoxy compounds not classified as the first epoxy compound can be used. In other words, among the epoxy compounds exemplified as the above second epoxy compound, any epoxy compound other than those used as the second and third epoxy compounds can be used as the fourth epoxy compound. In the photocurable composition, the fourth epoxy compound is an epoxy compound having a lower content than the contents of the second epoxy compound and the third epoxy compound. The fourth epoxy compound can be used alone or in combination of two or more.

[0069] Preferably, the photocurable composition further contains a curing agent. As the curing agent, known and commonly used photo cationic polymerization initiators can be used. The curing agent can be used alone or in combination of two or more.

[0070] Examples of the photo cationic polymerization initiator may include diazonium salt compounds, iodonium salt compounds, sulfonium salt compounds, phosphonium salt compounds, selenium salt compounds, oxonium salt compounds, ammonium salt compounds, bromide salt compounds, etc. In the present disclosure, it is preferable to use a sulfonium salt compound among them because a cured product having excellent curability can be formed.

[0071] Examples of the anionic part of the photo cationic polymerization initiator may include [(Y) S B(Phf) 4-S (in the formula, Y represents a phenyl group or a biphenyl group, Phf is a phenyl group in which at least one hydrogen atom is substituted with at least one selected from a perfluoroalkyl group, a perfluoroalkoxy group, and a halogen atom, and s is an integer from 0 to 3), BF4, [(Rf)nPF 6-n(wherein Rf represents an alkyl group in which at least 80% of the hydrogen atoms are replaced by fluorine atoms, and n represents an integer from 0 to 5), AsF6, SbF6, pentafluorohydroxyantimonate, etc.

[0072] Examples of the photo cationic polymerization initiator may include (4-hydroxyphenyl)methylbenzylsulfonium tetrakis(pentafluorophenyl)borate, 4-(4-biphenylthio)phenyl-4-biphenylylphenylsulfonium tetrakis(pentafluorophenyl)borate, 4-(phenylthio)phenyl diphenylsulfonium phenyltris(pentafluorophenyl)borate, [4-(4-biphenylthio)phenyl]-4-biphenylylphenylsulfonium phenyltris(pentafluorophenyl)borate, diphenyl[4-(phenylthio)phenyl]sulfonium tris(pentafluoroethyl)trifluorophosphate, diphenyl[4-(phenylthio)phenyl]sulfonium tetrakis(pentafluorophenyl)borate, diphenyl[4-(phenylthio)phenyl]sulfonium hexafluorophosphate, 4-(4-biphenylthio)phenyl-4-biphenylylphenylsulfonium tris(pentafluoroethyl)trifluorophosphate, bis[4-(diphenylsulfonio)phenyl]sulfide phenyltris(pentafluorophenyl)borate, [4-(2-thioxanthonylthio)phenyl]phenyl-2-thioxanthonylsulfonium phenyltris(pentafluorophenyl)borate, 4-(phenylthio)phenyl diphenylsulfonium hexafluoroantimonate, etc.

[0073] Relative to the total amount (100 parts by mass) of all cation-curable compounds included in the curable composition, the amount of the curing agent used (formulated) is preferably 0.01 to 15 parts by mass, more preferably 0.03 to 10 parts by mass, still more preferably 0.05 to 10 parts by mass, and particularly preferably 0.1 to 5 parts by mass. By using the curing agent within the above range, a cured product having excellent adhesion to the substrate can be obtained.

[0074] [Other compounds]

[0075] The photocurable composition of the present disclosure may contain compounds other than the above compounds. Examples of other compounds may include solvents, antioxidants, metal oxide particles, rubber particles, silicone-based or fluorine-containing antifoaming agents, silane coupling agents, fillers, plasticizers, antistatic agents, flame retardants, colorants, ultraviolet absorbers, ion adsorbents, pigments, mold release agents, etc. The content (formulation amount) of these various additives is preferably 5% by mass or less based on the total amount (100% by mass) of the curable composition.

[0076] [Primer coat]

[0077] As an example according to the present disclosure, a primer coat composed of a cured product of the photocurable composition can be mentioned. The primer coat can be obtained by applying the above photocurable composition on at least one surface of a substrate and curing it.

[0078] The substrate may include a single layer or multiple layers composed of the same or different materials. A resin substrate, a glass substrate, a metal substrate, etc. can be used for the substrate, and from the viewpoint of adhesion to the undercoat, a glass substrate is preferred.

[0079] The undercoat can be formed using common coating methods. For example, well-known methods such as dipping, roll coating, gravure coating, reverse coating, air knife coating, comma coating, die coating, screen printing, spraying, intaglio offset printing, and organic vapor deposition can be used. Examples of the curing treatment can include light irradiation using a mercury lamp, a xenon lamp, a carbon arc lamp, a metal halide lamp, sunlight, an electron beam source, a laser source, an LED light source, etc. It is preferred to irradiate within a range where the total irradiation dose should be, for example, 300 to 10000 mJ / cm 2 Alternatively, a film pre-coated on another substrate by the above formation method can be transferred to the substrate using a transfer method (such as adhesive transfer, heat transfer, UV transfer, etc.).

[0080] After completion of the light irradiation, it is preferred to further perform an annealing treatment to remove internal strain, and for example, it is preferred to heat the layer at a temperature of 100°C to 200°C for 30 minutes to about 1 hour.

[0081] When visually inspecting the appearance of the above undercoat after curing, it is preferred that it can be applied to the substrate without any shrinkage, and more preferably, the surface of the undercoat can be evenly applied without any roughness.

[0082] When making 100 squares in a grid pattern by scratching the undercoat with a cutter blade at 1 mm intervals according to JIS K 5600-5-6, attaching a tape thereto, then peeling the tape in the 90° direction, and visually inspecting whether the surface of the undercoat is peeled off after adhesion of the tape to the surface of the undercoat, it is preferred that at least 90 squares remain, more preferably at least 95 squares remain, and particularly preferably 100 squares remain. The structure in which at least 90 squares remain on the substrate can exhibit sufficient adhesion between the substrate and the undercoat.

[0083] The thickness of the undercoat is preferably 0.1 to 15 μm and more preferably 1 to 10 μm. The undercoat having a thickness within the above range can exhibit adhesion and make it easier to improve the surface hardness of the hard coat when laminating the hard coat.

[0084] [Laminate]

[0085] As an embodiment according to the present disclosure, a laminate including a substrate, a primer coat, and a hard coat can be mentioned. The laminate can be produced by further forming a hard coat on the primer coat formed on the substrate. The laminate structure in the laminate can be formed on the surface (one surface) on one side of the substrate and can be formed on the surfaces (two surfaces) on both sides. The laminate can have layers other than the primer coat and the hard coat. From the viewpoint of exhibiting the adhesion of the laminate, it is preferable that the substrate, the primer coat, and the hard coat are laminated in this order.

[0086] The above hard coat preferably contains a curable resin, and it is preferable that the curable resin contains a polyorganosilsesquioxane having a structural unit represented by the following formula (1) (hereinafter also referred to as "the polyorganosilsesquioxane of the present disclosure"). In other words, the curable composition (hereinafter also referred to as "hard coat agent") for forming the hard coat preferably contains a polyorganosilsesquioxane having a structural unit represented by the following formula (1). As described below, the hard coat agent can contain other components such as a curing agent (particularly a photo cationic polymerization initiator or a photo radical polymerizable initiator) and an antioxidant.

[0087] [C3]

[0088]

[0089] [In formula (1), R 1 represents a group containing a functional group curable by active energy rays.]

[0090] The polyorganosilsesquioxane of the present disclosure is characterized by having a structural unit represented by the above formula (1). The polyorganosilsesquioxane of the present disclosure preferably has a structural unit represented by the following formula (I) (which may also be referred to as "T3 form") and a structural unit represented by the following formula (II) (which may also be referred to as "T2 form"). In addition, the polyorganosilsesquioxane of the present disclosure preferably has a structural unit represented by formula (4) described below.

[0091] [C4]

[0092]

[0093] [C5]

[0094]

[0095] The structural unit represented by the above formula (1) is generally composed of [RSiO 3 / 2The silsesquioxane structural unit (so-called T unit) represented. In the above formula, R represents a hydrogen atom or a monovalent organic group, and the same applies hereinafter. The structural unit represented by the above formula (1) is formed by hydrolysis and condensation reactions of corresponding hydrolyzable trifunctional silane compounds (specifically, for example, the compound represented by the following formula (a)).

[0096] R in formula (1) 1 A group (monovalent group) representing a group containing a functional group curable by active energy rays. That is, the polyorganosilsesquioxane of the present disclosure is a photo cation-curable compound (photo cation-polymerizable compound) or a photo radical-curable compound (photo radical-polymerizable compound) having at least a functional group curable by active energy rays in the molecule.

[0097] The "photo cation-polymerizable functional group" in the group containing a functional group curable by active energy rays is not particularly limited as long as it has photo cation-polymerizability, and examples thereof may include an epoxy group, an oxetanyl group, a vinyl ether group, a vinylphenyl group, etc. The "photo radical-polymerizable functional group" in the group containing a functional group curable by active energy rays is not particularly limited as long as it has photo radical-polymerizability, and examples thereof may include (meth)acryloyloxy, (meth)acrylamide group, vinyl group, vinylthio group, etc. From the viewpoint of the surface hardness (e.g., H or higher) of the cured product (coating film), an epoxy group, (meth)acryloyloxy, etc. are preferred as the functional group curable by active energy rays, and an epoxy group is particularly preferred.

[0098] Examples of the group containing an epoxy group may include, but are not particularly limited to, known and commonly used groups having an ethylene oxide ring. From the viewpoints of the curability of the hard coating agent and the scratch resistance and toughness of the cured product (coating film), the group represented by the following formula (1a), the group represented by the following formula (1b), the group represented by the following formula (1c), and the group represented by the following formula (1d) are preferred, the group represented by the following formula (1a) and the group represented by the following formula (1c) are more preferred, and the group represented by the following formula (1a) is further preferred.

[0099] [C6]

[0100]

[0101] [C7]

[0102]

[0103] [C8]

[0104]

[0105] [C9]

[0106]

[0107] In formula (1a), R 1a represents a linear or branched alkylene group. Examples of the linear or branched alkylene group may include linear or branched alkylene groups having 1 to 10 carbon atoms, such as methylene, methylmethylene, dimethylmethylene, ethylene, propylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, and decamethylene. Among them, from the viewpoints of scratch resistance and toughness of the cured product (coating film), R 1a is preferably a linear alkylene group having any one of 1 to 4 carbon atoms and a branched alkylene group having 3 or 4 carbon atoms, more preferably ethylene, trimethylene, or propylene, and still more preferably ethylene or trimethylene.

[0108] In formula (1b), R 1b represents a linear or branched alkylene group, and examples thereof include the same groups as those of R 1a . Among them, from the viewpoints of scratch resistance and toughness of the cured product (coating film), as R 1b , a linear alkylene group having any one of 1 to 4 carbon atoms and a branched alkylene group having 3 or 4 carbon atoms are preferred, ethylene, trimethylene, and propylene are more preferred, and ethylene and trimethylene are still more preferred.

[0109] In formula (1c), R 1c represents a linear or branched alkylene group, and examples thereof include the same groups as those of R 1a . Among them, from the viewpoints of scratch resistance and toughness of the cured product (coating film), as R 1c , a linear alkylene group having any one of 1 to 4 carbon atoms and a branched alkylene group having 3 or 4 carbon atoms are preferred, ethylene, trimethylene, and propylene are more preferred, and ethylene and trimethylene are still more preferred.

[0110] In formula (1d), R 1d represents a linear or branched alkylene group, and examples thereof include the same groups as those of R 1a . Among them, from the viewpoints of scratch resistance and toughness of the cured product (coating film), as R 1d , a linear alkylene group having any one of 1 to 4 carbon atoms and a branched alkylene group having 3 or 4 carbon atoms are preferred, ethylene, trimethylene, and propylene are more preferred, and ethylene and trimethylene are still more preferred.

[0111] From the viewpoints of the scratch resistance and toughness of the cured product (coating film), as R in formula (1) 1 , the group represented by the above formula (1a) (wherein R 1a is an ethylene group) [among them, 2-(3’,4’-epoxycyclohexyl)ethyl] is particularly preferred.

[0112] Examples of the group containing an oxetane group may include, but are not particularly limited to, known and commonly used groups having an oxetane ring. Examples thereof may include the oxetane group itself and a group in which one or more hydrogen atoms (usually at least one and preferably one hydrogen atom) of an alkyl group (preferably an alkyl group having any one of 1 to 10 carbon atoms and more preferably an alkyl group having any one of 1 to 5 carbon atoms) are substituted by one or more oxetane groups. From the viewpoints of the curability of the hard coating agent and the scratch resistance and toughness of the cured product (coating film), 3-oxetanyl, oxetane-3-ylmethyl, 3-ethyloxetane-3-ylmethyl, 2-(oxetane-3-yl)ethyl, 2-(3-ethyloxetane-3-yl)ethyl, 3-(oxetane-3-ylmethoxy)propyl, 3-(3-ethyloxetane-3-ylmethoxy)propyl, etc. are preferred.

[0113] Examples of the group containing a vinyl ether group may include, but are not particularly limited to, known and commonly used groups having a vinyl ether group. Examples thereof may include the vinyl ether group itself and a group in which one or more hydrogen atoms (usually at least one and preferably one hydrogen atom) of an alkyl group (preferably an alkyl group having any one of 1 to 10 carbon atoms and more preferably an alkyl group having any one of 1 to 5 carbon atoms) are substituted by one or more vinyl ether groups. From the viewpoints of the curability of the hard coating agent and the scratch resistance and toughness of the cured product (coating film), vinyloxymethyl, 2-(vinyloxy)ethyl, 3-(vinyloxy)propyl, etc. are preferred.

[0114] Examples of the group containing a vinylphenyl may include, but are not particularly limited to, known and commonly used groups having a vinylphenyl ring. Examples thereof may include vinylbenzene itself and a group in which one or more hydrogen atoms (usually at least one and preferably one hydrogen atom) of an alkyl group (preferably an alkyl group having any one of 1 to 10 carbon atoms and more preferably an alkyl group having any one of 1 to 5 carbon atoms) are substituted by one or more vinylphenyls. From the viewpoints of the curability of the hard coating agent and the scratch resistance and toughness of the cured product (coating film), 4-vinylphenyl, 3-vinylphenyl, 2-vinylphenyl, etc. are preferred.

[0115] Examples of the group containing a (meth)acryloyloxy group may include, but are not particularly limited to, known and commonly used groups having a (meth)acryloyloxy group. Examples thereof may include the (meth)acryloyloxy group itself and a group in which one or more hydrogen atoms (usually at least one and preferably one hydrogen atom) of an alkyl group (preferably an alkyl group having any one of 1 to 10 carbon atoms and more preferably an alkyl group having any one of 1 to 5 carbon atoms) are substituted with one or more (meth)acryloyloxy groups. From the viewpoints of the curability of the hard coat agent and the scratch resistance and toughness of the cured product (coating film), 2-((meth)acryloyloxy)ethyl, 3-((meth)acryloyloxy)propyl, etc. are preferred.

[0116] Examples of the group containing a (meth)acrylamide group may include, but are not particularly limited to, known and commonly used groups having a (meth)acrylamide group. Examples thereof may include the (meth)acrylamide group itself and a group in which one or more hydrogen atoms (usually at least one and preferably one hydrogen atom) of an alkyl group (preferably an alkyl group having any one of 1 to 10 carbon atoms and more preferably an alkyl group having any one of 1 to 5 carbon atoms) are substituted with one or more (meth)acrylamide groups. From the viewpoints of the curability of the hard coat agent and the scratch resistance and toughness of the cured product (coating film), 2-((meth)acrylamido)ethyl, 3-((meth)acrylamido)propyl, etc. are preferred.

[0117] Examples of the group containing a vinyl group may include, but are not particularly limited to, known and commonly used groups having a vinyl group. Examples thereof may include the vinyl group itself and a group in which one or more hydrogen atoms (usually at least one and preferably one hydrogen atom) of an alkyl group (preferably an alkyl group having any one of 1 to 10 carbon atoms and more preferably an alkyl group having any one of 1 to 5 carbon atoms) are substituted with one or more vinyl groups. From the viewpoints of the curability of the hard coat agent and the scratch resistance and toughness of the cured product (coating film), vinyl, vinylmethyl, 2-vinylmethyl, 3-vinylpropyl, etc. are preferred.

[0118] Examples of the group containing a vinylthio group may include, but are not particularly limited to, known and commonly used groups having a vinylthio group. Examples thereof may include the vinylthio group itself and a group in which one or more hydrogen atoms (usually at least one and preferably one hydrogen atom) of an alkyl group (preferably an alkyl group having any one of 1 to 10 carbon atoms and more preferably an alkyl group having any one of 1 to 5 carbon atoms) are substituted with one or more vinylthio groups. From the viewpoints of the curability of the hard coat agent and the scratch resistance and toughness of the cured product (coating film), vinylthiomethyl, 2-(vinylthio)ethyl, 3-(vinylthio)propyl, etc. are preferred.

[0119] From the viewpoints of the scratch resistance and toughness of the cured product (coating film), as R in formula (1) 1 , a group including an epoxy group and a group including a (meth)acryloyloxy group are preferred. In particular, the group represented by the above formula (1a) (where R 1a is an ethylene group) [in particular, 2-(3’,4’-epoxycyclohexyl)ethyl], 3-(acryloyloxy)propyl, and 3-(methacryloyloxy)propyl are preferred.

[0120] The polyorganosilsesquioxane of the present disclosure may have only one structural unit represented by formula (1) or may have two or more structural units represented by formula (1).

[0121] In addition to the structural unit represented by the above formula (1), the polyorganosilsesquioxane of the present disclosure may also have a structural unit represented by the following formula (2) as a silsesquioxane structural unit [RSiO 3 / 2 .

[0122] [C10]

[0123]

[0124] The structural unit represented by the above formula (2) is a silsesquioxane structural unit (T unit) usually represented by [RSiO 3 / 2 . In other words, the structural unit represented by the above formula (2) is formed by a hydrolysis and condensation reaction of a corresponding hydrolyzable trifunctional silane compound (specifically, for example, a compound represented by the following formula (b)).

[0125] R in formula (2) 2 represents a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted alkenyl group. Examples of the aryl group may include a phenyl group, a tolyl group, a naphthyl group, etc. Examples of the aralkyl group may include a benzyl group, a phenethyl group, etc. Examples of the cycloalkyl group may include a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, etc. Examples of the alkyl group may include a straight-chain or branched alkyl group such as a methyl group, an ethyl group, a propyl group, a n-butyl group, an isopropyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, and an isopentyl group. Examples of the alkenyl group may include a straight-chain or branched alkenyl group such as a vinyl group, an allyl group, an isopropenyl group, etc.

[0126] As the substituted aryl, substituted aralkyl, substituted cycloalkyl, substituted alkyl, and substituted alkenyl mentioned above, at least one of the partial or total hydrogen atoms or the main chain skeleton of each of the aryl, aralkyl, cycloalkyl, alkyl, and alkenyl is substituted with at least one selected from the group consisting of: an ether group, an ester group, a carbonyl group, a siloxane group, a halogen atom (such as a fluorine atom), an acrylic group, a methacryloyl group, a mercapto group, an amino group, and a hydroxy group.

[0127] Among them, as R 2 , substituted or unsubstituted aryl, substituted or unsubstituted alkyl, and substituted or unsubstituted alkenyl are preferred, substituted or unsubstituted aryl is more preferred, and phenyl is further preferred.

[0128] In the polyorganosilsesquioxane of the present disclosure, the ratio of each silsesquioxane structural unit (the structural unit represented by formula (1) or the structural unit represented by formula (2)) can be adjusted as appropriate by the composition of the raw materials (hydrolyzable trifunctional silanes) used to form these structural units.

[0129] The polyorganosilsesquioxane of the present disclosure may have at least one silsesquioxane structural unit selected from the group consisting of: silsesquioxane structural units other than the above structural unit represented by formula (1) and the structural unit represented by formula (2) [RSiO 3 / 2 , the structural unit represented by [R3SiO 1 / 2 (so-called M unit), the structural unit represented by [R2SiO 2 / 2 (so-called D unit), and the structural unit represented by [SiO 4 / 2 (so-called Q unit). Examples of silsesquioxane structural units other than the above structural unit represented by formula (1) and the structural unit represented by formula (2) may include structural units represented by the following formula (3) and the like.

[0130] [C11]

[0131]

[0132] When the polyorganosilsesquioxane of the present disclosure has a structural unit represented by the above formula (I) (T3 form) and a structural unit represented by formula (II) (T2 form), the ratio [T3 form / T2 form] is not particularly limited and can be selected as appropriate within a range of, for example, 5 or more (e.g., 5 or more and 500 or less). The lower limit of the ratio [T3 form / T2 form] is preferably 20, more preferably 21, still more preferably 23, and further preferably 25. When the ratio [T3 form / T2 form] is 5 or more, the surface hardness, scratch resistance, and toughness of the cured product (coating film) tend to be improved. At the same time, the upper limit of the ratio [T3 form / T2 form] is preferably 500, more preferably 100, still more preferably 50, and further preferably 40. When the ratio [T3 form / T2 form] is 500 or less, the compatibility with other components in the hard coating agent is improved, and the viscosity is suppressed. Therefore, the polyorganosilsesquioxane is easy to handle and easy to apply as a hard coating agent.

[0133] If the structural unit represented by the above formula (I) is described in more detail, it is represented by the following formula (I’). Further, if the structural unit represented by the above formula (II) is described in more detail, it is represented by the following formula (II’). Each of the three oxygen atoms bonded to the silicon atom shown in the structure represented by the following formula (I’) is bonded to another silicon atom (a silicon atom not shown in formula (I’)). At the same time, each of the two oxygen atoms located above or below the silicon atom shown in the structure represented by formula (II’) is bonded to another silicon atom (a silicon atom not shown in formula (II’)). In other words, both the T3 and T2 forms are structural units (T units) formed by the hydrolysis and condensation reaction of the corresponding hydrolyzable trifunctional silane compound.

[0134] [C12]

[0135]

[0136] [C13]

[0137]

[0138] R in the above formula (I) a (similarly applicable to R in formula (I’)) a and R in the above formula (II) b (similarly applicable to R in formula (II’)) b each represents a group containing a functional group curable by active energy rays, 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. Ra and R b Specific examples of may include those identical to R in Formula (1) above 1 and R in Formula (2) above 2 The R in Formula (I) a and the R in Formula (II) b each independently derives from a group bonded to a silicon atom in a hydrolyzable trifunctional silane compound used as a raw material for the polyorganosilsesquioxane of the present disclosure (groups other than alkoxy groups and halogen atoms; for example, R in Formulas (a) to (c) described below 1 , R 2 , a hydrogen atom, etc.).

[0139] The R in Formula (II) c (similarly applicable to R in Formula (II’) c ) represents a hydrogen atom or an alkyl group having a carbon number of any one of 1 to 4. Examples of the alkyl group having a carbon number of 1 to 4 may include linear or branched alkyl groups having a carbon number of 1 to 4, such as methyl, ethyl, propyl, isopropyl, butyl, and isobutyl. The alkyl group in R in Formula (II) c usually derives from an alkyl group that forms an alkoxy group (for example, as the alkoxy group of X 1 to X 3 ) in the hydrolyzable silane compound used as a raw material for the polyorganosilsesquioxane of the present disclosure.

[0140] The ratio [T3 form / T2 form] in the polyorganosilsesquioxane of the present disclosure can be obtained, for example, by 29 Si-NMR spectrum measurement. In the 29 Si-NMR spectrum, since the silicon atoms in the structural unit (T3 form) represented by Formula (I) above and the silicon atoms in the structural unit (T2 form) represented by Formula (II) above show signals (peaks) at different positions (chemical shifts), the above ratio [T3 form / T2 form] can be obtained by calculating the integration ratio of these corresponding peaks. Specifically, for example, when the polyorganosilsesquioxane of the present disclosure is represented by Formula (1) above (where R 1When represented by a structural unit of 2-(3’,4’-epoxycyclohexyl)ethyl, the signal of the silicon atom in the structure represented by the above formula (I) (T3 form) appears at -64 to -70 ppm, and the signal of the silicon atom in the structure represented by the above formula (II) (T2 form) appears at -54 to -60 ppm. Therefore, in this case, the above ratio [T3 form / T2 form] can be obtained by calculating the integral ratio of the signal at -64 to -70 ppm (T3 form) to the signal at -54 to -60 ppm (T2 form). When R 1 is a group containing an energy ray-curable functional group other than 2-(3’,4’-epoxycyclohexyl)ethyl, [T3 form / T2 form] can be obtained in the same manner.

[0141] The 29 Si-NMR spectrum of the polyorganosilsesquioxane of the present disclosure can be measured using, for example, the following apparatus and conditions.

[0142] Measuring apparatus: Product name “JNM-ECA 500 NMR” (manufactured by JEOL Ltd.)

[0143] Solvent: Deuterated chloroform

[0144] Number of accumulations: 1800

[0145] Measuring temperature: 25 °C

[0146] The case where the above 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) means that a certain amount of T2 form is present relative to the T3 form in the polyorganosilsesquioxane of the present disclosure. Examples of such T2 forms may 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), etc. 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 . R in the following formulas (4) to (6) c each represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, just like R in formula (II) c .

[0147] [C14]

[0148]

[0149] [C15]

[0150]

[0151] [C16]

[0152]

[0153] The polyorganosilsesquioxane of the present disclosure may have any one of a cage, an incomplete cage, a ladder, or a random sesquioxane structure, or a combination of two or more of these sesquioxane structures.

[0154] When the polyorganosilsesquioxane of the present disclosure has a structural unit represented by Formula (4), the ratio (total amount) of the structural unit represented by the above Formula (1) and the structural unit represented by the above Formula (4) relative to the total amount of siloxane structural units [total siloxane component units: total amount of M, D, T, and Q units] (100 mol%) is not particularly limited, and is preferably 55 mol% to 100 mol%, more preferably 65 mol% to 100 mol%, and still more preferably 80 mol% to 99 mol%. A ratio of 55 mol% or more can improve the curability of the hard coating agent and significantly enhance the scratch resistance and toughness of the cured product (coating film). The ratio of each siloxane structural unit in the polyorganosilsesquioxane of the present disclosure is calculated, for example, from the composition of the raw materials or by NMR spectrum measurement, etc.

[0155] The ratio (total amount) of the structural unit represented by the above Formula (2) and the structural unit represented by the above Formula (5) relative to the total amount of siloxane structural units [total siloxane component units: total amount of M, D, T, and Q units] (100 mol%) is not particularly limited, and is preferably 0 mol% to 70 mol%, more preferably 0 mol% to 60 mol%, still more preferably 0 mol% to 40 mol%, and particularly preferably 1 mol% to 15 mol%. A ratio of 70 mol% or less can relatively increase the ratio of the structural unit represented by Formula (1) and the structural unit represented by Formula (4), and thus, the hard coating agent tends to exhibit higher curability, and the scratch resistance and toughness of the cured product (coating film) tend to be higher.

[0156] In the polyorganosilsesquioxane of the present disclosure, the ratio (total amount) of the structural unit represented by the above formula (1), the structural unit represented by the above formula (2), the structural unit represented by the above formula (4), and the structural unit represented by the above formula (5) relative to the total amount of siloxane structural units [total siloxane component units: total amount of M, D, T, and Q units] (100 mol%) is not particularly limited, and is preferably 60 mol% to 100 mol%, more preferably 70 mol% to 100 mol%, and still more preferably 80 mol% to 100 mol%. When the ratio is 60 mol% or more, the scratch resistance and toughness of the cured product (coating film) tend to be higher.

[0157] By gel permeation chromatography, the number average molecular weight (Mn) of the polyorganosilsesquioxane of the present disclosure based on standard polystyrene is not particularly limited, and can be optionally selected within the range of 1000 to 50000. The lower limit of the number average molecular weight is preferably 1500, more preferably 1800, and still more preferably 2000. By setting the number average molecular weight to 1000 or more, the scratch resistance and toughness of the cured product (coating film) tend to be higher. On the contrary, the upper limit of the number average molecular weight is preferably 50000, more preferably 10000, and still more preferably 8000. By setting the number average molecular weight to 50000 or less (for example, 3000 or less), the compatibility with other components in the hard coating agent tends to be improved, and the scratch resistance and toughness of the cured product (coating film) tend to be higher.

[0158] By gel permeation chromatography, the molecular weight distribution (Mw / Mn) of the polyorganosilsesquioxane of the present disclosure based on standard polystyrene is not particularly limited, and can be optionally selected within the range of 1.0 to 4.0. The lower limit of the molecular weight distribution is preferably 1.0, more preferably 1.1, and still more preferably 1.2. When the molecular weight distribution is 1.1 or more, the hard coating agent may be in a liquid form, and the handleability tends to be improved. On the contrary, the upper limit of the molecular weight distribution is preferably 4.0, more preferably 3.0, and still more preferably 2.5. By controlling the molecular weight distribution to 4.0 or less, the scratch resistance and toughness of the cured product (coating film) tend to be higher.

[0159] The number average molecular weight and molecular weight distribution of the polyorganosilsesquioxane of the present disclosure can be measured using the following apparatus and conditions.

[0160] Measurement apparatus: Product name "LC-20AD" (manufactured by Shimadzu Corporation)

[0161] Columns: Shodex KF-801 × 2, KF-802, and KF-803 (manufactured by Showa Denko K.K.)

[0162] Measured temperature: 40 °C

[0163] Eluent: THF, sample concentration: 0.1% to 0.2% by mass

[0164] Flow rate: 1 mL / min

[0165] Detector: UV-VIS detector (trade name "SPD-20A", manufactured by Shimadzu Corporation)

[0166] Molecular weight: Based on standard polystyrene

[0167] The 5%-weight loss temperature (T d5 ) of the polyorganosilsesquioxane disclosed herein in an air atmosphere is not particularly limited and is preferably 330 °C or higher (e.g., 330 °C to 450 °C), more preferably 340 °C or higher, and further preferably 350 °C or higher. A 5%-weight loss temperature of 330 °C or higher tends to improve the scratch resistance and toughness of the cured product (coating film). In particular, when the polyorganosilsesquioxane disclosed herein has a ratio [T3 form / T2 form] of 5 or more and 500 or less, a number average molecular weight of 1,000 to 50,000, and a molecular weight distribution of 1.0 to 4.0, its 5%-weight loss temperature is controlled to 330 °C or higher. The 5%-weight loss temperature is the temperature at which 5% of the weight before heating is reduced when heated at a constant rate of temperature increase and is an index of heat resistance. The above 5%-weight loss temperature can be measured by TGA (thermogravimetric analysis) at a rate of temperature increase of 5 °C / min in an air atmosphere.

[0168] The polyorganosilsesquioxane disclosed herein can be manufactured by known and commonly used polysiloxane manufacturing methods without any particular limitation. For example, the polyorganosilsesquioxane can be manufactured by a method for hydrolyzing and condensing one or more hydrolyzable silane compounds. However, a hydrolyzable trifunctional silane compound (a compound represented by the following formula (a)) for forming the structural unit represented by the above-described formula (1) must be used as a necessary hydrolyzable silane compound.

[0169] More specifically, for example, the polyorganosilsesquioxane of the present disclosure can be produced by a method of hydrolyzing and condensing a compound represented by the following formula (a) (which is a hydrolyzable silane compound for forming a sesquisiloxane structural unit (T unit) in the polyorganosilsesquioxane of the present disclosure), and optionally a compound represented by the following formula (b) and a compound represented by the following formula (c).

[0170] [C17]

[0171]

[0172] [C18]

[0173]

[0174] [C19]

[0175]

[0176] The compound represented by formula (a) is a compound that forms the structural unit represented by formula (1) in the polyorganosilsesquioxane of the present disclosure. R in formula (a) 1 represents a group including a functional group curable by active energy rays, just like R in formula (1) 1 . In other words, as R in formula (a) 1 , the group represented by the above formula (1a), the group represented by the above formula (1b), the group represented by the above formula (1c), and the group represented by the above formula (1d) are preferred, the group represented by the above formula (1a) and the group represented by the above formula (1c) are more preferred, the group represented by the above formula (1a) is further preferred, and the group represented by the above formula (1a) (where R 1a is ethylene) [among them, 2-(3’,4’-epoxycyclohexyl)ethyl] is particularly preferred. In addition, as R in formula (a) as described above 1 , 3-(acryloyloxy)propyl and 3-(methacryloyloxy)propyl are also preferred.

[0177] X in formula (a) 1 represents an alkoxy group or a halogen atom. Examples of the alkoxy group in X 1 can include alkoxy groups having 1 to 4 carbon atoms, such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, and the like. Examples of the halogen atom in X 1 can include fluorine atom, chlorine atom, bromine atom, iodine atom, and the like. Among them, as X 1 , an alkoxy group is preferred, and methoxy and ethoxy are more preferred. These three X1 may be the same as or different from each other.

[0178] The compound represented by the above formula (b) is a compound that forms the structural unit represented by formula (2) in the polyorganosilsesquioxane of the present disclosure. R in formula (b) 2 represents a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted alkenyl group, as is R in formula (2) 2 . In other words, as R in formula (b) 2 , substituted or unsubstituted aryl groups, substituted or unsubstituted alkyl groups, and substituted or unsubstituted alkenyl groups are preferred, substituted or unsubstituted aryl groups are more preferred, and phenyl groups are further preferred.

[0179] X in formula (b) 2 represents an alkoxy group or a halogen atom. Specific examples of X 2 may include those exemplified as X 1 . Among them, as X 2 , alkoxy groups are preferred, and methoxy and ethoxy groups are more preferred. These three Xs 2 may be the same as or different from each other.

[0180] The compound represented by the above formula (c) is a compound that forms the structural unit represented by formula (3) in the polyorganosilsesquioxane of the present disclosure. X in the above formula (c) 3 represents an alkoxy group or a halogen atom. Specific examples of X 3 may include those exemplified as X 1 . Among them, as X 3 , alkoxy groups are preferred, and methoxy and ethoxy groups are more preferred. These three Xs 3 may be the same as or different from each other.

[0181] Hydrolysable silane compounds other than those represented by the above formulas (a) to (c) can be used in combination with the above hydrolysable silane compounds. Examples thereof may include hydrolysable trifunctional silane compounds other than those represented by the above formulas (a) to (c), hydrolysable monofunctional silane compounds that form M units, hydrolysable difunctional silane compounds that form D units, hydrolysable tetrafunctional silane compounds that form Q units, and the like.

[0182] The amount and composition of the above hydrolyzable silane compounds can be adjusted as appropriate according to the desired structure of the polyorganosilsesquioxane disclosed herein. For example, the amount of the compound represented by formula (a) used is not particularly limited, and is preferably 55 mol% to 100 mol%, more preferably 65 mol% to 100 mol%, and still more preferably 80 mol% to 99 mol% relative to the total amount (100 mol%) of the hydrolyzable silane compounds used.

[0183] The amount of the compound represented by formula (b) used is not particularly limited, and is preferably 0 mol% to 70 mol%, more preferably 0 mol% to 60 mol%, still more preferably 0 mol% to 40 mol%, and particularly preferably 1 mol% to 15 mol% relative to the total amount (100 mol%) of the hydrolyzable silane compounds used.

[0184] Furthermore, the ratio (ratio of the total amount) of the compound represented by formula (a) and the compound represented by formula (b) relative to the total amount (100 mol%) of the hydrolyzable silane compounds to be used is not particularly limited, and is preferably 60 mol% to 100 mol%, more preferably 70 mol% to 100 mol%, and still more preferably 80 mol% to 100 mol%.

[0185] When two or more hydrolyzable silane compounds are used in combination as the hydrolyzable silane compound, the hydrolysis and condensation reactions of these hydrolyzable silane compounds can be carried out simultaneously or sequentially. When the above reactions are carried out sequentially, the order of carrying out these reactions is not particularly limited.

[0186] The hydrolysis and condensation reactions of the above-mentioned hydrolyzable silane compounds can be carried out in a single stage or in more than two stages. For example, in order to efficiently produce the polyorganosilsesquioxane of the present disclosure (hereinafter also referred to as "low molecular weight polyorganosilsesquioxane") having a ratio [T3 form / T2 form] of less than 20 and / or a number average molecular weight of less than 2500, the hydrolysis and condensation reactions are preferably carried out in a single stage. In order to efficiently produce the polyorganosilsesquioxane of the present disclosure (hereinafter also referred to as "high molecular weight polyorganosilsesquioxane") having a ratio [T3 form / T2 form] of 20 or more and / or a number average molecular weight of 2500 or more, the hydrolysis and condensation reactions are carried out in more than two stages (preferably in two stages); that is, the above-mentioned low molecular weight polyorganosilsesquioxane is used as a raw material to further carry out the hydrolysis and condensation reactions more than once. Examples are described below in which the hydrolysis and condensation reactions of the hydrolyzable silane compounds are carried out in a single stage to obtain a low molecular weight polyorganosilsesquioxane, and the low molecular weight polyorganosilsesquioxane is further subjected to the hydrolysis and condensation reactions to obtain a high molecular weight polyorganosilsesquioxane, but the manufacturing method of the polyorganosilsesquioxane of the present disclosure is not limited thereto.

[0187] When the hydrolysis and condensation reactions of the present disclosure are carried out in two stages, preferably, the first stage hydrolysis and condensation reaction produces a low molecular weight polyorganosilsesquioxane having a ratio [T3 form / T2 form] of 5 or more and less than 20 and a number average molecular weight of 1000 or more and less than 2500, and in the second stage, the obtained low molecular weight polyorganosilsesquioxane is further subjected to the hydrolysis and condensation reactions to obtain a high molecular weight polyorganosilsesquioxane having a ratio [T3 form / T2 form] of 20 or more and 500 or less and a number average molecular weight of 2500 or more and 50000 or less.

[0188] The first stage hydrolysis and condensation reaction can be carried out in the presence or absence of a solvent. Among them, it is preferred to carry out the process in the presence of a solvent. Examples of the above solvents can include aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene; ethers such as diethyl ether, dimethoxyethane, tetrahydrofuran, and dioxane; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; esters such as methyl acetate, ethyl acetate, isopropyl acetate, and butyl acetate; amides such as N,N-dimethylformamide or N,N-dimethylacetamide; nitriles such as acetonitrile, propionitrile, and benzonitrile; alcohols such as methanol, ethanol, isopropanol, and butanol; etc. As the above solvents, ketones and ethers are preferred among them. The solvents can be used alone or in combination of two or more.

[0189] The amount of the solvent used in the first-stage hydrolysis and condensation reaction is not particularly limited, and the amount of the solvent used can be adjusted as appropriate within the range of 0 to 2,000 parts by mass relative to the total amount of the hydrolyzable silane compound of 100 parts by mass according to the desired reaction time and the like.

[0190] Preferably, the first-stage hydrolysis and condensation reaction is carried out in the presence of a catalyst and water. The catalyst can be an acid catalyst or a base catalyst, but a base catalyst is preferred in order to suppress the decomposition of functional groups curable by active energy rays such as epoxy groups. Examples of the acid catalyst can include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, and boric acid; phosphate esters; carboxylic acids such as acetic acid, formic acid, and trifluoroacetic acid; sulfonic acids such as methanesulfonic acid, trifluoromethanesulfonic acid, and p-toluenesulfonic acid; solid acids such as activated clay; Lewis acids such as iron chloride, etc. Examples of the base catalyst can include hydroxides of alkali metals such as lithium hydroxide, sodium hydroxide, potassium hydroxide, and cesium hydroxide; hydroxides of alkaline earth metals such as magnesium hydroxide, calcium hydroxide, and barium hydroxide; carbonates of alkali metals such as lithium carbonate, sodium carbonate, potassium carbonate, and cesium carbonate; carbonates of alkaline earth metals such as magnesium carbonate; bicarbonates of alkali metals such as lithium bicarbonate, sodium bicarbonate, potassium bicarbonate, and cesium bicarbonate; organic acid salts of alkali metals (e.g., acetates) such as lithium acetate, sodium acetate, potassium acetate, and cesium acetate; organic acid salts of alkaline earth metals (e.g., acetates) such as magnesium acetate; alkoxides of alkali metals such as lithium methoxide, sodium methoxide, sodium ethoxide, sodium isopropoxide, potassium ethoxide, and potassium tert-butoxide; phenoxides of alkali metals such as sodium phenoxide; amines (tertiary amines, etc.) such as triethylamine, N-methylpiperidine, 1,8-diazabicyclo[5.4.0]undec-7-ene, and 1,5-diazabicyclo[4.3.0]non-5-ene; nitrogen-containing aromatic heterocyclic compounds such as pyridine, 2,2'-bipyridine, and 1,10-phenanthroline; etc. The catalyst can be used alone or in combination of two or more. A catalyst dissolved or dispersed in water, a solvent, etc. can also be used.

[0191] The amount of the catalyst used in the first-stage hydrolysis and condensation reaction is not particularly limited, and the amount of the catalyst used can be adjusted as appropriate within the range of 0.002 to 0.200 moles / mole of the total amount of the hydrolyzable silane compound.

[0192] The amount of the water used in the first-stage hydrolysis and condensation reaction is not particularly limited, and the amount of the water used can be adjusted as appropriate within the range of 0.5 to 20 moles / mole of the total amount of the hydrolyzable silane compound.

[0193] The manner of adding water in the first-stage hydrolysis and condensation reaction is not particularly limited, and the entire amount (the total amount used) of the water to be used can be added batchwise or sequentially. If water is added sequentially, the water can be added continuously or intermittently.

[0194] As reaction conditions for the first-stage hydrolysis and condensation reaction, it is particularly important to select reaction conditions such that the above ratio [T3 form / T2 form] in the low-molecular-weight polyorganosilsesquioxane is 5 or more and less than 20. The reaction temperature for the first-stage hydrolysis and condensation reaction is not particularly limited, and is preferably from 40°C to 100°C and more preferably from 45°C to 80°C. By controlling the reaction temperature within the above range, the above ratio [T3 form / T2 form] tends to be more efficiently controlled to be 5 or more and less than 20. The reaction time for the first-stage hydrolysis and condensation reaction is not particularly limited, and is preferably from 0.1 to 10 hours and more preferably from 1.5 to 8 hours. The first-stage hydrolysis and condensation reaction can be carried out under normal pressure or under pressure or reduced pressure. The atmosphere for the first-stage hydrolysis and condensation reaction is not particularly limited, and can be, for example, an inert gas atmosphere (such as a nitrogen or argon atmosphere), or an atmosphere in which oxygen is present (such as an air atmosphere), but an inert gas atmosphere is preferred.

[0195] The above-described first-stage hydrolysis and condensation reaction produces a low-molecular-weight polyorganosilsesquioxane. After completion of the above first-stage hydrolysis and condensation reaction, it is preferable to neutralize the catalyst to suppress the decomposition of functional groups curable by active energy rays, such as the ring-opening of epoxy groups. The low-molecular-weight polyorganosilsesquioxane can also be separated and purified by separation methods (such as washing with water, washing with acid, washing with alkali, filtration, concentration, distillation, extraction, crystallization, recrystallization, and column chromatography) or by separation means combining these methods.

[0196] By subjecting the low-molecular-weight polyorganosilsesquioxane obtained by the first-stage hydrolysis and condensation reaction to a second-stage hydrolysis and condensation reaction, a high-molecular-weight polyorganosilsesquioxane can be produced. The second-stage hydrolysis and condensation reaction can be carried out in the presence or absence of a solvent. When the second-stage hydrolysis and condensation reaction is carried out in the presence of a solvent, the solvents listed for the first-stage hydrolysis and condensation reaction can be used. As the solvent for the second-stage hydrolysis and condensation reaction, the low-molecular-weight polyorganosilsesquioxane containing the reaction solvent, extraction solvent, etc. for the first-stage hydrolysis and condensation reaction can be used as it is or after removing some of the solvent. The solvents can be used alone or in combination of two or more.

[0197] When a solvent is used in the second-stage hydrolysis and condensation reaction, the amount of the solvent used is not particularly limited and can be adjusted as appropriate according to the desired reaction time, etc. within the range of 0 to 2000 parts by mass relative to 100 parts by mass of the low-molecular-weight polyorganosilsesquioxane.

[0198] Preferably, the second-stage hydrolysis and condensation reaction is carried out in the presence of a catalyst and water. The above catalyst can be those listed in the first stage of the hydrolysis and condensation reaction, and in order to inhibit the decomposition of functional groups curable by active energy rays such as epoxy groups, the catalyst is preferably a base catalyst and more preferably a hydroxide of an alkali metal, such as sodium hydroxide, potassium hydroxide, and cesium hydroxide; and carbonates of alkali metals, such as lithium carbonate, sodium carbonate, potassium carbonate, cesium carbonate, etc. The catalyst can be used alone or in combination of two or more. A catalyst dissolved or dispersed in water, a solvent, etc. can also be used.

[0199] The amount of the catalyst used in the second-stage hydrolysis and condensation reaction is not particularly limited and can preferably be adjusted as appropriate in the range of 0.01 to 10,000 ppm, more preferably in the range of 0.1 to 1,000 ppm, relative to the low-molecular-weight polyorganosilsesquioxane (1,000,000 ppm).

[0200] The amount of water used in the second-stage hydrolysis and condensation reaction is not particularly limited and can preferably be adjusted as appropriate in the range of 10 to 100,000 ppm, more preferably in the range of 100 to 20,000 ppm, relative to the low-molecular-weight polyorganosilsesquioxane (1,000,000 ppm). If the amount of water used is greater than 100,000 ppm, the ratio [T3 form / T2 form] of the high-molecular-weight polyorganosilsesquioxane and the number-average molecular weight tend to be difficult to control within a specified range.

[0201] The manner of adding water in the second-stage hydrolysis and condensation reaction is not particularly limited, and all of the water to be used (the total amount used) can be added in one batch or sequentially. If water is added sequentially, water can be added continuously or intermittently.

[0202] As reaction conditions for the second-stage hydrolysis and condensation reaction, it is particularly important to select reaction conditions such that in the high molecular weight polyorganosilsesquioxane, the above ratio [T3 form / T2 form] is 20 or more and 500 or less and the number average molecular weight is 2,500 to 50,000. The reaction temperature for the second-stage hydrolysis and condensation reaction varies depending on the catalyst used and is not particularly limited, and is preferably 5°C to 200°C and more preferably 30°C to 100°C. By controlling the reaction temperature within the above range, the ratio [T3 form / T2 form] and the number average molecular weight tend to be more efficiently controlled within the desired range. The reaction time for the second-stage hydrolysis and condensation reaction is not particularly limited, and is preferably 0.5 to 1,000 hours and more preferably 1 to 500 hours. By performing the hydrolysis and condensation reaction within the above reaction temperature range while monitoring the ratio [T3 form / T2 form] and the number average molecular weight by timely sampling, a high molecular weight polyorganosilsesquioxane having a desired ratio [T3 form / T2 form] and number average molecular weight can also be obtained.

[0203] The second-stage hydrolysis and condensation reaction can be carried out under normal pressure or under pressure or reduced pressure. The atmosphere for the second-stage hydrolysis and condensation reaction is not particularly limited, and may be, for example, an inert gas atmosphere (such as a nitrogen or argon atmosphere), or an atmosphere in which oxygen is present (such as an air atmosphere), but an inert gas atmosphere is preferred.

[0204] A high molecular weight polymer polyorganosilsesquioxane can be obtained by the second-stage hydrolysis and condensation reaction. After completion of the above second-stage hydrolysis and condensation reaction, it is preferable to neutralize the catalyst to inhibit decomposition of functional groups curable by active energy rays, such as ring opening of epoxy groups. The high molecular weight polyorganosilsesquioxane can also be separated and purified by separation methods (such as washing with water, washing with acid, washing with alkali, filtration, concentration, distillation, extraction, crystallization, recrystallization, and column chromatography) or by separation means combining these methods.

[0205] Since the polyorganosilsesquioxane of the present disclosure has the structure described above, an excellent cured product (coating film) having scratch resistance and toughness can be formed by applying a hard coat agent containing the polyorganosilsesquioxane as an essential component and curing it.

[0206] In the hard coat agent, the polyorganosilsesquioxane of the present disclosure can be used alone or in combination of two or more.

[0207] The content (mixing amount) of the polyorganosilsesquioxane disclosed herein in the above hard coat agent is not particularly limited, and is preferably 70% or more and less than 100% by mass, more preferably 80% to 99.8% by mass, and further preferably 90% to 99.5% by mass, based on the total amount (100% by mass) of the hard coat agent (excluding the solvent). By setting the content of the polyorganosilsesquioxane disclosed herein to 70% or more by mass, the scratch resistance and toughness of the cured product (coating film) tend to be higher. Conversely, by setting the content of the polyorganosilsesquioxane disclosed herein to less than 100% by mass, a curing agent can be included, which tends to allow the hard coat agent to cure more efficiently.

[0208] The ratio of the polyorganosilsesquioxane disclosed herein to the total amount (100% by mass) of the photo cation-curable compound or photo radical-curable compound in the above hard coat agent is not particularly limited, and is preferably 70% to 100% by mass, more preferably 75% to 98% by mass, and further preferably 80% to 95% by mass. By setting the content of the photo cation-curable compound or photo radical-curable compound to 70% or more by mass, the scratch resistance and toughness of the cured product (coating film) tend to be higher.

[0209] The hard coat agent may further contain a curing agent for promoting the curing reaction by irradiation with active energy rays. It is particularly preferred to include a photo cationic polymerization initiator or a photo radical polymerization initiator as the curing agent, since the curing time until the product becomes non-tacky can be shortened.

[0210] As the photo cationic polymerization initiator, the same photo cationic polymerization initiators as those listed for the photocurable composition can be used.

[0211] The photo radical polymerization initiator is a compound that can initiate or promote the photo radical polymerization reaction of a photo radical-curable compound such as the polyorganosilsesquioxane disclosed herein.

[0212] Examples of the photo radical polymerization initiator may include benzophenone, benzyl acetophenone, benzyl dimethyl ketone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, dimethoxy acetophenone, dimethoxy phenyl acetophenone, diethoxy acetophenone, diphenyl disulfite, methyl o-benzoylbenzoate, ethyl 4-dimethylaminobenzoate, 2,4-diethyl thioxanthone, 2-methyl-1-[4-(methyl)phenyl]-2-morpholinopropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-amino-2-benzoyl-1-phenylalkane compounds such as 2-dimethylamino-2-(4-morpholinyl)benzoyl-1-phenylpropane, tetra(tert-butylperoxycarbonyl)benzophenone, benzyl, 2-hydroxy-2-methyl-1-phenylpropan-1-one, aminobenzene derivatives such as 4,4-bis-diethylaminobenzophenone, imidazole compounds such as 2,2'-bis(2-(chlorophenyl)-4,5,4',5'-tetraphenyl-1,2'-biimidazole, halogenated methylated triazine compounds such as 2,6-bis(trichloromethyl)-4-(4-methoxynaphthalen-1-yl)-1,3,5-triazine, halogenated methyl oxadiazole compounds such as 2-trichloromethyl-5-(2-benzofuran-2-yl-vinyl)-1,3,4-oxadiazole, etc. A photosensitizer may be added as needed.

[0213] In the hard coat agent, the curing agent may be used alone or in combination of two or more.

[0214] The content (mixing amount) of the curing agent in the hard coat agent is not particularly limited, and is preferably 0.01 to 10.0 parts by mass, more preferably 0.05 to 5.0 parts by mass, and still more preferably 0.1 to 3.0 parts by mass, relative to the total amount (100 parts by mass; total amount of the active energy ray curable compound) of the polyorganosilsesquioxane and other active energy ray curable compounds (which will be described later) of the present disclosure. By setting the content of the curing agent to 0.01 part by mass or more, the curing reaction can proceed efficiently and sufficiently, and the scratch resistance and toughness of the cured product (coating film) tend to be higher. On the contrary, by setting the content of the curing agent to 5.0 parts by mass or less, the storage life of the hard coat agent is further improved, and the coloring of the cured product (coating film) tends to be suppressed.

[0215] The hard coat agent may further contain a photo-curable compound other than the polyorganosilsesquioxane disclosed herein (which may be referred to as "other photo-curable compounds"). Examples of the other photo-curable compounds may include photo cation-curable compounds other than the polyorganosilsesquioxane disclosed herein (which may be referred to as "other photo cation-curable compounds") and / or photo radical-curable compounds other than the polyorganosilsesquioxane disclosed herein (which may be referred to as "other photo radical-curable compounds").

[0216] As the other photo cation-curable compounds, known and commonly used photo cation-curable compounds can be used without any particular limitation. Examples thereof may include epoxy compounds, oxetane compounds, vinyl ether compounds, etc., other than the polyorganosilsesquioxane disclosed herein. In the hard coat agent, the other photo cation-curable compounds may be used alone or in combination of two or more.

[0217] Examples of the above epoxy compounds and oxetane compounds may include the same compounds as those described in the photo-curable composition mentioned above.

[0218] As the vinyl ether compound, known and commonly used compounds having at least one vinyl ether group in the molecule can be used without any particular limitation. Examples thereof may include 2-hydroxyethyl vinyl ether (ethylene glycol mono vinyl ether), 3-hydroxypropyl vinyl ether, 2-hydroxypropyl vinyl ether, 2-hydroxyisopropyl vinyl ether, 4-hydroxybutyl vinyl ether, 3-hydroxybutyl vinyl ether, 2-hydroxybutyl vinyl ether, 3-hydroxyisobutyl vinyl ether, 2-hydroxyisobutyl vinyl ether, 1-methyl-3-hydroxypropyl vinyl ether, 1-methyl-2-hydroxypropyl vinyl ether, 1-hydroxymethylpropyl vinyl ether, 4-hydroxycyclohexyl vinyl ether, 1,6-hexanediol mono vinyl ether, 1,6-hexanediol divinyl ether, 1,8-octanediol divinyl ether, 1,4-cyclohexanedimethanol mono vinyl ether, 1,4-cyclohexanedimethanol divinyl ether, 1,3-cyclohexanedimethanol mono vinyl ether, 1,3-cyclohexanedimethanol divinyl ether, 1,2-cyclohexanedimethanol mono vinyl ether, 1,2-cyclohexanedimethanol divinyl ether, p-xylene glycol mono vinyl ether, p-xylene glycol divinyl ether, m-xylene glycol mono vinyl ether, m-xylene glycol divinyl ether, o-xylene glycol mono vinyl ether, o-xylene glycol divinyl ether, ethylene glycol divinyl ether, diethylene glycol mono vinyl ether, diethylene glycol divinyl ether, triethylene glycol mono vinyl ether, triethylene glycol divinyl ether, tetraethylene glycol mono vinyl ether, tetraethylene glycol divinyl ether, pentaethylene glycol mono vinyl ether, pentaethylene glycol divinyl ether, oligo(ethylene glycol) mono vinyl ether, oligo(ethylene glycol) divinyl ether, polyethylene glycol mono vinyl ether, polyethylene glycol divinyl ether, dipropylene glycol mono vinyl ether, dipropylene glycol divinyl ether, tripropylene glycol mono vinyl ether, tripropylene glycol divinyl ether, tetrapropylene glycol mono vinyl ether, tetrapropylene glycol divinyl ether, pentapropylene glycol mono vinyl ether, pentapropylene glycol divinyl ether, oligo(propylene glycol) mono vinyl ether, oligo(propylene glycol) divinyl ether, polypropylene glycol mono vinyl ether, polypropylene glycol divinyl ether, isosorbide divinyl ether, oxanorbornene divinyl ether, phenyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, octyl vinyl ether, cyclohexyl vinyl ether, hydroquinone divinyl ether, 1,4-butanediol divinyl ether, cyclohexanedimethanol divinyl ether, trimethylolpropane divinyl ether, trimethylolpropane trivinyl ether, bisphenol-A divinyl ether, bisphenol-F divinyl ether, hydroxyoxanorbornane methanol divinyl ether, 1,4-cyclohexanediol divinyl ether, pentaerythritol trivinyl ether, pentaerythritol tetra vinyl ether, dipentaerythritol penta vinyl ether, dipentaerythritol hexa vinyl ether, etc.

[0219] In the hard coat agent, the epoxy compound is preferably used in combination with other photocationically curable compounds in addition to the polyorganosilsesquioxane disclosed herein.

[0220] As other photo-radical curable compounds, known and commonly used photo-radical curable compounds can be used without any particular limitation. Examples thereof may include compounds having at least one photo-radically polymerizable group (such as (meth)acrylic groups, (meth)acryloxy groups, (meth)acrylamide groups, vinyl ether groups, vinyl aryls, and vinyloxycarbonyl groups) in one molecule other than the polyorganosilsesquioxanes disclosed herein. In the hard coat agent, other photo-radical curable compounds can be used alone or in combination of two or more.

[0221] Examples of the compounds having at least one (meth)acrylic group in one molecule may include 1-buten-3-one, 1-penten-3-one, 1-hexen-3-one, 4-phenyl-1-buten-3-one, 5-phenyl-1-penten-3-one, etc., and derivatives thereof, etc.

[0222] Examples of the compounds having at least one (meth)acryloxy group in one molecule may include monomers or oligomers having at least one (meth)acryloxy group in one molecule.

[0223] Examples of monomers having at least one (meth)acryloyloxy group in one molecule may include methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, n-butoxyethyl (meth)acrylate, butoxy diethylene glycol (meth)acrylate, methoxy triethylene glycol (meth)acrylate, methoxy polyethylene glycol (meth)acrylate, cyclohexyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, isobornyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, acrylic acid, methacrylic acid, 2-(meth)acryloyloxyethyl succinate, 2-(meth)acryloyloxyethyl hexahydrophthalate, 2-(meth)acryloyloxyethyl-2-hydroxypropyl phthalate, glycidyl (meth)acrylate, 2-hydroxyethyl methacrylate phosphate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, decane di(meth)acrylate, glycerol di(meth)acrylate, 2-hydroxy-3-(meth)acryloyloxypropyl (meth)acrylate, dimethylol tricyclodecane di(meth)acrylate, (meth)acrylic acid trifluoroethyl ester, (meth)acrylic acid perfluorooctylethyl ester, isopentyl (meth)acrylate, isomyristyl (meth)acrylate, γ-(meth)acryloyloxypropyltrimethoxysilane, 2-(meth)acryloyloxyethyl isocyanate, 1,1-bis(acryloyloxy)ethyl isocyanate, 2-(2-(meth)acryloyloxyethoxy)ethyl isocyanate, 3-(meth)acryloyloxypropyltriethoxysilane, etc., and derivatives thereof, etc.

[0224] Examples of oligomers having at least one (meth)acryloyloxy group in one molecule may include urethane (meth)acrylate oligomers, epoxy (meth)acrylate oligomers, polyether (meth)acrylate oligomers, polyester (meth)acrylate oligomers, etc.

[0225] Examples of the urethane (meth)acrylate oligomer may include polycarbonate urethane (meth)acrylate, polyester urethane (meth)acrylate, polyether urethane (meth)acrylate, caprolactone urethane (meth)acrylate, etc. The urethane (meth)acrylate oligomer can be obtained by the reaction between an isocyanate compound (which can be obtained from a polyol and a diisocyanate) and a (meth)acrylate monomer having a hydroxyl group. Examples of the polyol may include polycarbonate diol, polyester polyol, polyether polyol, and polycaprolactone polyol.

[0226] The epoxy (meth)acrylate oligomer can be obtained, for example, by the esterification reaction of the ethylene oxide ring of a low molecular weight bisphenol epoxy resin or a novolac epoxy resin with acrylic acid.

[0227] The polyether (meth)acrylate oligomer can be obtained by a dehydration-condensation reaction of a polyol to obtain a polyether oligomer having hydroxyl groups at both ends, and then esterifying the hydroxyl groups at both ends with acrylic acid.

[0228] The polyester (meth)acrylate oligomer can be obtained, for example, by the condensation of a polycarboxylic acid and a polyol to obtain a polyester oligomer having hydroxyl groups at both ends, and then esterifying the hydroxyl groups at both ends with acrylic acid.

[0229] The weight average molecular weight of the oligomer having at least one (meth)acryloyloxy group in one molecule is preferably 100,000 or less and particularly preferably 500 to 50,000.

[0230] Examples of the compound having at least one (meth)acrylic acid amino group in one molecule may include 4-(meth)acryloylmorpholine, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide, N-propyl(meth)acrylamide, N-isopropyl(meth)acrylamide, N-butyl(meth)acrylamide, N-n-butoxymethyl(meth)acrylamide, N-hexyl(meth)acrylamide, N-octyl(meth)acrylamide, etc., and their derivatives, etc.

[0231] Examples of compounds having at least one vinyl ether group in one molecule may include 3,3-bis(ethenyloxymethyl)oxetane, 2-hydroxyethyl vinyl ether, 3-hydroxypropyl vinyl ether, 2-hydroxypropyl vinyl ether, 2-hydroxyisopropyl vinyl ether, 4-hydroxybutyl vinyl ether, 3-hydroxybutyl vinyl ether, 2-hydroxybutyl vinyl ether, 3-hydroxyisobutyl vinyl ether, 2-hydroxyisobutyl vinyl ether, 1-methyl-3-hydroxypropyl vinyl ether, 1-methyl-2-hydroxypropyl vinyl ether, 1-hydroxymethylpropyl vinyl ether, 4-hydroxycyclohexyl vinyl ether, 1,6-hexanediol mono vinyl ether, 1,4-cyclohexanedimethanol mono vinyl ether, 1,3-cyclohexanedimethanol mono vinyl ether, 1,2-cyclohexanedimethanol mono vinyl ether, p-xylene glycol mono vinyl ether, m-xylene glycol mono vinyl ether, o-xylene glycol mono vinyl ether, diethylene glycol mono vinyl ether, triethylene glycol mono vinyl ether, tetraethylene glycol mono vinyl ether, pentaethylene glycol mono vinyl ether, oligo(ethylene glycol) mono vinyl ether, polyethylene glycol mono vinyl ether, dipropylene glycol mono vinyl ether, tripropylene glycol mono vinyl ether, tetrapropylene glycol mono vinyl ether, pentapropylene glycol mono vinyl ether, oligo(propylene glycol) mono vinyl ether, polypropylene glycol mono vinyl ether, etc., and derivatives thereof, etc.

[0232] Examples of compounds having at least one vinyl aryl in one molecule may include styrene, divinylbenzene, methoxystyrene, ethoxystyrene, hydroxystyrene, vinylnaphthalene, vinylanthracene, 4-vinylphenyl acetate, (4-vinylphenyl)dihydroxyborane, N-(4-vinylphenyl)maleimide, etc., and derivatives thereof, etc.

[0233] Examples of compounds having at least one vinyloxycarbonyl in one molecule may include isopropyl formate, isopropyl acetate, isopropyl propionate, isopropyl butyrate, isopropyl isobutyrate, isopropyl hexanoate, isopropyl valerate, isopropyl isovalerate, isopropyl lactate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl hexanoate, vinyl octanoate, vinyl laurate, vinyl myristate, vinyl palmitate, vinyl stearate, vinyl cyclohexanecarboxylate, vinyl pivalate, vinyl octanoate, vinyl chloroacetate, divinyl adipate, vinyl acrylate, vinyl methacrylate, vinyl crotonate, vinyl sorbate, vinyl benzoate, vinyl cinnamate, etc., and their derivatives, etc.

[0234] In the hard coating agent, other active energy ray-curable compounds may be used alone or in combination of two or more.

[0235] When the above hard coat agent contains other energy ray-curable compounds, its content (mixing amount) is not particularly limited, and the content is preferably 3% to 50% by mass, more preferably 5% to 40% by mass, and still more preferably 7% to 30% by mass relative to the total amount of the polyorganosilsesquioxane and other energy ray-curable compounds disclosed herein (100% by mass; total amount of energy ray-curable compounds). By reducing the content of other energy ray-curable compounds to 50% by mass or less, the scratch resistance and toughness of the cured product (coating film) tend to be higher. Conversely, by setting the content of other energy ray-curable compounds to 3% by mass or more, desired properties (e.g., rapid curing or viscosity adjustment of the hard coat agent) can be imparted to the hard coat agent or the cured product (coating film).

[0236] When the above hard coat agent contains a vinyl ether compound (particularly, a vinyl ether compound having at least one hydroxyl group in the molecule), its content (mixing amount) is not particularly limited, and the content is preferably 0.01% to 10% by mass, more preferably 0.05% to 9% by mass, and still more preferably 1% to 8% by mass relative to the total amount of the polyorganosilsesquioxane and other energy ray-curable compounds disclosed herein (100% by mass; total amount of energy ray-curable compounds). By controlling the content of the vinyl ether compound within the above range, the surface hardness of the cured product (coating film) tends to be higher, and a cured product (coating film) having a very high surface hardness also tends to be obtained even when the irradiation dose of energy rays (e.g., ultraviolet rays) is low. Particularly, by controlling the content of the vinyl ether compound having at least one hydroxyl group in the molecule to the above range, the surface hardness of the cured product (coating film) tends to be particularly high.

[0237] The hard coat agent preferably contains an antioxidant. When the hard coat agent contains an antioxidant, the cured product (coating film) can be more improved.

[0238] As the antioxidant, known and commonly used antioxidants can be used without any particular limitation. Examples thereof may include phenolic antioxidants (phenolic compounds), hindered amine antioxidants (hindered amine compounds), phosphorus antioxidants (phosphorus compounds), sulfur-containing antioxidants (sulfur-containing compounds), etc.

[0239] Examples of phenolic antioxidants can include monophenols such as 2,6-di-tert-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-tert-butyl-p-ethylphenol, and stearyl-β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate; bisphenols such as 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), 4,4'-thiobis(3-methyl-6-tert-butylphenol), 4,4'-butylidenebis(3-methyl-6-tert-butylphenol), and 3,9-bis[1,1-dimethyl-2-{β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy}ethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane; polymeric phenols such as 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, tetra[methylene-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate]methane, bis[3,3'-bis-(4'-hydroxy-3'-tert-butylphenyl)butyrate]glycol ester, 1,3,5-tris(3',5'-di-tert-butyl-4'-hydroxybenzyl)-s-triazine-2,4,6-(1H,3H,5H)trione, tocopherol; etc.

[0240] Examples of hindered amine antioxidants can include bis(1,2,2,6,6-pentamethyl-4-piperidyl)) [[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]butyl malonate, bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, methyl-1,2,2,6,6-pentamethyl-4-piperidyl sebacate, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, etc.

[0241] Examples of phosphorus antioxidants can include phosphites such as triphenyl phosphite, diphenylisodecyl phosphite, phenyl diisodecyl phosphite, tris(nonylphenyl) phosphite, diisodecyl pentaerythritol phosphite, tris(2,4-di-tert-butylphenyl) phosphite, cyclopentanetetraylbis(octadecyl) phosphite, cyclopentanetetraylbis(2,4-di-tert-butylphenyl) phosphite, cyclopentanetetraylbis(2,4-di-tert-butyl-4-methylphenyl) phosphite, and bis[2-tert-butyl-6-methyl-4-{2-(octadecyloxycarbonyl)ethyl}phenyl] hydrogen phosphite; oxaphosphaphenanthrene oxides such as 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-(3,5-di-tert-butyl-4-hydroxybenzyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, etc.

[0242] Examples of the sulfur-containing antioxidant may include dodecyl mercaptan, dilauryl 3,3'-thiodipropionate, dimyristyl 3,3'-thiodipropionate, distearyl 3,3'-thiodipropionate, and the like.

[0243] Among them, preferred antioxidants include phenolic antioxidants, phosphorus antioxidants, and sulfur-containing antioxidants. In particular, phenolic antioxidants are preferred. In the hard coat agent, the antioxidants can be used alone or in combination of two or more.

[0244] When the hard coat agent contains an antioxidant, its content (blending amount) is not particularly limited, and preferably is 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 compounds curable by active energy rays in the hard coat agent. If the antioxidant content is less than 0.05 part by mass, the cured product (coating film) may be insufficient. On the contrary, if the antioxidant content exceeds 5 parts by mass, the cured product (coating film) may be easily colored.

[0245] Preferably, the hard coat agent contains a compound having at least one thermopolymerizable functional group and at least one photopolymerizable functional group in one molecule (which may be hereinafter referred to as "Compound A"). When the above hard coat agent contains Compound A together with the polyorganosilsesquioxane disclosed herein, the crosslinking density can be effectively increased when formed into a cured product, and it is possible to easily impart high surface hardness and excellent properties to the cured product (coating film).

[0246] The "thermopolymerizable 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. Examples thereof may include a hydroxyl group, an epoxy group, an oxetanyl group, a vinyl ether group, and the like. From the viewpoint of the surface hardness of the coating film disclosed herein, a hydroxyl group and an epoxy group are preferred. When Compound A has at least two thermopolymerizable functional groups, these thermopolymerizable functional groups may be the same or different from each other.

[0247] 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 thereof may include (meth)acryloyl, vinyl, and the like. From the viewpoint of the surface hardness of the coating film disclosed herein, (meth)acryloyl is preferred. When Compound A has two or more photopolymerizable functional groups, these photopolymerizable functional groups may be the same or different from each other.

[0248] The number of thermopolymerizable functional groups in Compound A in one molecule is not particularly limited as long as it is at least 1, and for example, 1 to 5 is preferred, 1 to 3 is more preferred, and 1 or 2 is further preferred. The number of photopolymerizable functional groups in Compound A in one molecule is not particularly limited as long as it is at least 1, and for example, 1 to 5 is preferred, 1 to 3 is more preferred, and 1 or 2 is further preferred.

[0249] The functional group equivalent of the thermopolymerizable functional group of Compound A is not particularly limited, and preferably is 50 to 500, more preferably 80 to 480, and still more preferably 120 to 450. If the functional group equivalent is less than 50, the cured product (coating film) may be insufficient. On the contrary, if the 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 by the following formula.

[0250] [Functional group equivalent of thermopolymerizable functional group] = [Molecular weight of Compound A] / [Number of thermopolymerizable functional groups in Compound A]

[0251] The functional group equivalent of the photopolymerizable functional group of Compound A is not particularly limited, and preferably is 50 to 500, more preferably 80 to 480, and still more preferably 120 to 450. If the functional group equivalent is less than 50, the cured product (coating film) may be insufficient. On the contrary, if the 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 by the following formula.

[0252] [Functional group equivalent of photopolymerizable functional group] = [Molecular weight of Compound A] / [Number of photopolymerizable functional groups in Compound A]

[0253] Specific examples of Compound A may include compounds having an epoxy group and / or a hydroxyl group and a (meth)acryloyl group in one molecule, such as 3,4-epoxycyclohexylmethyl (meth)acrylate, glycidyl (meth)acrylate, dipropylene glycol diglycidyl ether di(meth)acrylate (a compound obtained by reacting two epoxy groups of dipropylene glycol diglycidyl ether with (meth)acrylic acid), dipropylene glycol diglycidyl ether semi(meth)acrylate (a compound obtained by reacting one epoxy group of dipropylene glycol diglycidyl ether with (meth)acrylic acid), bisphenol A epoxy di(meth)acrylate (a compound obtained by reacting two epoxy groups of bisphenol A diglycidyl ether with (meth)acrylic acid), bisphenol A epoxy semi(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 semi(meth)acrylate, bisphenol S epoxy di(meth)acrylate, and bisphenol S epoxy semi(meth)acrylate; compounds having an oxetanyl group and a (meth)acryloyl group in one molecule, such as 3-oxetanylmethyl (meth)acrylate, 3-methyl-3-oxetanylmethyl (meth)acrylate, 3-ethyl-3-oxetanylmethyl (meth)acrylate, 3-butyl-3-oxetanylmethyl (meth)acrylate, 3-hexyl-3-oxetanylmethyl (meth)acrylate; compounds having a vinyl ether group and a (meth)acryloyl group in one molecule, such as 2-vinyloxyethyl (meth)acrylate, 3-vinyloxypropyl (meth)acrylate, 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 ester, 3-vinyloxybutyl (meth)acrylate, 1-methyl-2-vinyloxypropyl (meth)acrylate, 2-vinyloxybutyl (meth)acrylate, 4-vinyloxycyclohexyl (meth)acrylate, 6-vinyloxyhexyl (meth)acrylate, 4-vinyloxymethylcyclohexylmethyl (meth)acrylate, 3-vinyloxymethylcyclohexylmethyl (meth)acrylate, 2-vinyloxycyclohexylmethyl (meth)acrylate, p-vinyloxymethylphenyl (meth)acrylate, m-vinyloxymethylphenyl (meth)acrylate, o-vinyloxymethylphenyl (meth)acrylate, 2-(vinyloxyethoxy)ethyl (meth)acrylate, 2-(vinyloxyisopropoxy)ethyl (meth)acrylate, 2-(vinyloxyethoxy)propyl (meth)acrylate, 2-(vinyloxyethoxy)isopropyl (meth)acrylate, 2-(vinyloxyisopropoxy)propyl (meth)acrylate, 2-(vinyloxyisopropoxy)isopropyl (meth)acrylate, 2-(vinyloxyethoxyethoxy)ethyl (meth)acrylate, 2-(vinyloxyethoxyisopropoxy)ethyl (meth)acrylate, 2-(vinyloxyisopropoxyethoxy)ethyl (meth)acrylate, 2-(vinyloxyisopropoxyisopropoxy)ethyl (meth)acrylate, 2-(vinyloxyethoxyethoxy)propyl (meth)acrylate, 2-(vinyloxyethoxyisopropoxy)propyl (meth)acrylate, 2-(vinyloxyisopropoxyethoxy)propyl (meth)acrylate, 2-(vinyloxyisopropoxyisopropoxy)propyl (meth)acrylate, 2-(vinyloxyethoxyethoxy)isopropyl (meth)acrylate, 2-(vinyloxyethoxyisopropoxy)isopropyl (meth)acrylate, 2-(vinyloxyisopropoxyethoxy)isopropyl (meth)acrylate, 2-(vinyloxyisopropoxyisopropoxy)isopropyl (meth)acrylate, 2-(vinyloxyethoxyethoxyethoxy)ethyl (meth)acrylate, 2-(vinyloxyethoxyethoxyethoxyethoxy)ethyl (meth)acrylate, 2-(isopropenyloxyethoxy)ethyl (meth)acrylate, 2-(isopropenyloxyethoxyethoxy)ethyl (meth)acrylate, 2-(isopropenyloxyethoxyethoxyethoxy)ethyl (meth)acrylate, 2-(isopropenyloxyethoxyethoxyethoxyethoxy)ethyl (meth)acrylate, polyethylene glycol monovinyl ether (meth)acrylate and polypropylene glycol monovinyl ether (meth)acrylate; etc.,

[0254] From the viewpoint of the surface hardness of the cured product (coating film), a compound having an epoxy group and / or a hydroxyl group as a thermopolymerizable functional group and a (meth)acryloyl group as a photopolymerizable functional group in one molecule is preferred as Compound A. Specifically, methyl 3,4-epoxycyclohexyl (meth)acrylate, glycidyl (meth)acrylate, dipropylene glycol diglycidyl ether hemimethacrylate, bisphenol A epoxy hemimethacrylate, bisphenol F epoxy hemimethacrylate, bisphenol S epoxy hemimethacrylate, etc. are preferred.

[0255] In the hard coat agent, Compound A can be used alone or in combination of two or more. Compound A can be produced by a known method. For example, Compound A can be obtained by reacting a part of the thermopolymerizable functional group (e.g., epoxy group or hydroxyl group) of a compound having at least two thermopolymerizable functional groups in one molecule with a carboxylic acid having a photopolymerizable functional group (e.g., acrylic acid, methacrylic acid, etc.) or its derivative, or by other methods.

[0256] The content (blending amount) of Compound A in the above hard coat agent is not particularly limited, and is preferably 1.0 to 100 parts by mass, more preferably 1.3 to 75 parts by mass, and still more preferably 1.5 to 50 parts by mass relative to the total amount of the polyorganosilsesquioxane and other active energy ray curable compounds (total amount of active energy ray curable compounds) of the present disclosure as 100 parts by mass of the solid content. By setting the content of Compound A to 1 part by mass or more, the cured product (coating film) tends to be improved. On the contrary, by setting the content of Compound A to 100 parts by mass or less, the surface hardness of the cured product (coating film) tends to be maintained.

[0257] The above hard coat agent preferably contains a fluorine-containing photopolymerizable resin. The fluorine-containing photopolymerizable resin is a resin (oligomer) having a fluorine-containing group (such as a fluorinated aliphatic hydrocarbon skeleton) and a photopolymerizable functional group in the molecule. When the hard coat agent contains a fluorine-containing photopolymerizable resin together with the polyorganosilsesquioxane and Compound A of the present disclosure, the hard coat agent has the characteristics of effectively increasing the crosslinking density on the surface of the coating film when formed into a cured product, improving the appearance (such as surface smoothness) of the cured product (coating film), and improving surface hardness, scratch resistance, and stain resistance. In particular, when the fluorine-containing photopolymerizable resin is blended with Compound A in the hard coat agent, the effect is remarkable.

[0258] The photopolymerizable functional group of the fluorine-containing photopolymerizable resin can be the same as the "photopolymerizable functional group" of the above Compound A. From the viewpoints of scratch resistance and stain resistance of the coating film of the present disclosure, (meth)acryloyl group is preferred. When the fluorine-containing photopolymerizable resin has two or more photopolymerizable functional groups, these photopolymerizable functional groups can be the same or different from each other.

[0259] The number of photopolymerizable functional groups contained in the above fluorine-containing photopolymerizable resin in one molecule is not particularly limited as long as it is at least 1, and for example, 1 to 5 is preferable, and 1 to 3 is more preferable.

[0260] The "fluorine-containing group" of the fluorine-containing photopolymerizable resin is not particularly limited as long as it has a fluorine atom, and examples thereof may include those having a fluorinated aliphatic hydrocarbon skeleton. Examples of the fluorinated aliphatic hydrocarbon skeleton may include C 1-10 Fluorinated alkanes such as fluoromethane, fluoroethane, fluoropropane, fluoroisopropane, fluorobutane, fluoroisobutane, fluorotert-butane, fluoropentane, and fluorohexane.

[0261] In these fluorinated aliphatic hydrocarbon skeletons, it is sufficient that some of the hydrogen atoms are substituted with fluorine atoms. A perfluorinated aliphatic hydrocarbon skeleton in which all hydrogen atoms are substituted with fluorine atoms is preferable because the scratch resistance, slip characteristics, and stain resistance of the coating film can be improved.

[0262] In addition, the fluorinated aliphatic hydrocarbon skeleton may form a polyfluorinated alkylene ether skeleton, which is a repeating unit via an ether bond. The fluorinated aliphatic hydrocarbon group as the repeating unit may be at least one selected from the group consisting of C 1-4 Fluoroalkylenes such as fluoromethylene, fluoroethylene, fluoropropylene, and fluoroisopropylene. The number of repetitions (degree of polymerization) of the polyfluorinated alkylene ether unit is, for example, 10 to 3000, preferably 30 to 1000, and more preferably 50 to 500.

[0263] In addition to the above-described "photopolymerizable functional group" and "fluorine-containing group", the fluorine-containing photopolymerizable resin may further have a silicone group. When the fluorine-containing photopolymerizable resin further has a silicone group, the affinity with the polyorganosilsesquioxane of the present disclosure is improved, and the surface hardness, scratch resistance, and stain resistance of the cured product (coating film) tend to be further improved. The silicone group is a group having a polyorganosiloxane skeleton, which may be a polyorganosiloxane formed by M units, D units, T units, or Q units, but a polyorganosiloxane formed by D units is usually preferably used. As the organic group of the polyorganosiloxane, C 1-4 Alkyl groups and aryl groups are generally used, and methyl and phenyl groups (particularly, methyl) are generally used. The number of repetitions (degree of polymerization) of the siloxane unit is, for example, 2 to 3000, preferably 3 to 2000, and more preferably 5 to 1000.

[0264] These fluorine-containing photopolymerizable resins may be used alone or in combination of two or more.

[0265] The content (mixing ratio) of the fluorine-containing photopolymerizable resin in the above hard coat agent is not particularly limited, and is, for example, 0.01 to 15 parts by mass, preferably 0.02 to 10 parts by mass, more preferably 0.03 to 5 parts by mass, and still more preferably 0.04 to 3 parts by mass with respect to the total amount of the polyorganosilsesquioxane and other active energy ray-curable compounds (total amount of active energy ray-curable compounds) of the present disclosure as 100 parts by mass of the solid content. By setting the content of the fluorine-containing photopolymerizable resin to 0.01 part by mass or more, the scratch resistance and stain resistance of the cured product (coating film) tend to be improved.

[0266] Preferably, the hard coat agent contains a surface conditioner. As the above surface conditioner, known and commonly used compounds added for the purpose of defoaming, leveling, preventing foaming, etc. can be used.

[0267] As the defoaming agent, leveling agent, and anti-foaming agent, for example, aqueous or non-aqueous compounds composed of main components selected from the following can be used, polymer main components (such as butadiene, acrylics, and olefins) or silicone main components (such as silicone and fluorine-modified silicone).

[0268] The content (mixing ratio) of the surface conditioner in the above hard coat agent is not particularly limited, and 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 still more preferably 0.2 to 3 parts by mass with respect to the total amount of the polyorganosilsesquioxane and other active energy ray-curable compounds (total amount of active energy ray-curable compounds) of the present disclosure as 100 parts by mass of the solid content. By setting the content of the surface conditioner to 0.01 part by mass or more, the leveling characteristics of the cured product (coating film) tend to be improved.

[0269] The hard coat agent may preferably further contain a solvent. The solvent is not particularly limited as long as these solvents can dissolve the polyorganosilsesquioxane of the present disclosure and additives that can be used as needed, and do not inhibit polymerization.

[0270] Preferably, a solvent that can impart fluidity suitable for application to the hard coat and can be easily removed by heating at a temperature that can inhibit the progress of polymerization is used, and preferably one or more solvents having a boiling point of 170°C or lower (at 1 atm) are used (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; etc.).

[0271] The solvent is preferably used in the hard coat agent in a concentration of the nonvolatile components of, for example, about 5% to 100% by mass, preferably 10% to 80% by mass, and particularly preferably 20% to 70% by mass, because the applicability is excellent. However, the amount added is not limited to the above range, and the optimal amount to be added should be selected to have a viscosity that can achieve a reasonable film thickness. That is, if the amount of the solvent used is excessive, the viscosity of the hard coat agent tends to be low, and it tends to be difficult to form a coating film with an appropriate film thickness. On the contrary, if the amount of the solvent used is too small, the viscosity of the hard coat agent tends to be too high, and it tends to be difficult to apply it uniformly to the glass substitute substrate.

[0272] The above hard coat agent may further contain common additives as other optional components, including inorganic fillers such as precipitated silica, wet-process 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 treated with organosilicon compounds such as organohalosilanes, organoalkoxysilanes, or organosilazanes; fine powders of organic resins such as silicone resins, epoxy resins, and fluororesins; fillers of conductive metal powders such as silver and copper; curing aids; stabilizers (light stabilizers, heat stabilizers, heavy metal passivators, etc.); ultraviolet absorbers (triazine ultraviolet absorbers, benzotriazole ultraviolet absorbers, benzophenone ultraviolet absorbers, oxybenzophenone ultraviolet absorbers, salicylate ultraviolet absorbers, cyanoacrylate ultraviolet absorbers); flame retardants (phosphorus flame retardants, halogen-containing flame retardants, inorganic flame retardants, etc.), flame retardant aids; reinforcing agents (other fillers, etc.); nucleating agents; coupling agents (silane coupling agents, etc.); lubricants; waxes; plasticizers; mold release agents; impact improvers; hue improvers; transparency enhancers; rheology modifiers (flow modifiers, etc.), processability improvers; colorants (dyes, pigments, etc.); antistatic agents; dispersants; surface modifiers (slip agents, etc.); matting agents; defoaming agents; foam suppressants; degassing agents; antimicrobial agents; preservatives; viscosity adjusters; thickeners; photosensitizers; foaming agents, etc. These additives can be used alone or in combinations of two or more.

[0273] Although not particularly limited, the hard coat agent can be prepared by stirring and mixing the above components at room temperature or under heating (if necessary). The hard coat agent can be used as a single-component composition in which each component is premixed and used as it is, or as a multi-component (e.g., two-component) composition in which two or more components stored separately are mixed at a predetermined ratio before use.

[0274] The above hard coat agent is not particularly limited and is preferably a liquid at normal temperature (about 25°C). More specifically, the hard coat agent has a viscosity preferably of 300 to 20,000 mPa·s, more preferably 500 to 10,000 mPa·s, and still more preferably 1,000 to 8,000 mPa·s, which is the viscosity of a solution diluted to 20% with a solvent [specifically, a hard coat agent solution having a proportion of 20% by mass of methyl isobutyl ketone] at 25°C. By setting the above viscosity to 300 mPa·s or more, the cured product (coating film) tends to be further improved. On the contrary, by setting the above viscosity to 20,000 mPa·s or less, the preparation and handling of the hard coat agent tend to be easier, and air bubbles tend not to remain in the cured product (coating film). The viscosity of the above hard coat agent is measured using a viscometer (product name "MCR 301", manufactured by Anton Paar Ltd.) at a swing angle of 5%, a frequency of 0.1 to 100 (1 / s), and a temperature of 25°C.

[0275] A laminate having a three-layer structure of a substrate, an undercoat, and a hard coat can be produced by applying the thus-prepared hard coat agent onto the undercoat by known and common methods and curing it.

[0276] The above method of coating and curing the hard coat can be carried out in the same manner as exemplified for the above undercoat. When ultraviolet rays are applied to cure the hard coat, the cumulative irradiation dose is preferably, for example, about 1 to 5000 mJ / cm 2 .

[0277] Specific curing conditions are not particularly limited, and for example, the above hard coat agent is first preferably heat-treated (pre-baked) at 60°C or higher, more preferably at 120°C or higher, and still more preferably at 150°C or higher for 10 seconds or more, more preferably for 30 seconds or more, and still more preferably for 60 seconds or more; next, the product is irradiated with ultraviolet rays (irradiation conditions (irradiation dose): preferably 300 mJ / cm 2 or more; irradiation intensity: 100 mW / cm 2 or more); and finally, the hard coat agent is heat-treated (aged) at preferably 120°C or higher, preferably for 0.5 hours or more to cure the hard coat agent. However, the curing conditions are not limited to this range. The pre-baking temperature and time, and the aging temperature and time can be appropriately selected according to the solvent used, and the ultraviolet irradiation conditions can also be appropriately selected according to the curing agent used.

[0278] The above hard coat agent can form a hard coat having high scratch resistance, surface hardness, and toughness by coating and curing, as described above. The laminate produced in this manner can improve the surface hardness of the hard coat while providing excellent adhesion.

[0279] The thickness of the hard coat 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 more makes it easier to improve the surface hardness.

[0280] The pencil hardness of the surface of the hard coat of the laminate is preferably 6H or more, preferably 7H or more, and particularly preferably 8H or more. The pencil hardness can be evaluated according to the method described in JIS K 5600-5-4 (750 g load). In the case of a pencil hardness of 6H or more, the above laminate tends to have sufficient surface hardness and excellent scratch resistance.

[0281] When, according to JIS K 5600-5-6, a cutter blade is used to scratch the laminate from the hard coat side at 1 mm intervals to make 100 squares in a grid pattern, a tape is attached thereto, then the tape is peeled off in the 90° direction, and the surface of the coating is visually inspected to see if it is peeled off after the adhesion of the tape to the surface of the coating, it is preferable that at least 90 squares remain, more preferably at least 95 squares remain, and particularly preferably 100 squares remain. When at least 90 squares remain on the laminate, it can be confirmed that the hard coat and the undercoat exhibit sufficient adhesion.

[0282] [Display device]

[0283] As an embodiment of the present disclosure, a display device provided with the above laminate can be mentioned. In the above display device, the above laminate is arranged such that, for example, the hard coat constitutes the visible side surface. The above display device is not particularly limited, and examples thereof include display devices such as organic EL display devices, inorganic EL display devices, and liquid crystal display devices. Since the surface of the hard coat has sufficient pencil hardness, the surface of the above display device is less likely to be scratched. The display device can also be used as a flexible display that can be bent, wound, etc.

[0284] Each embodiment disclosed in this specification can be combined with any other features disclosed in this specification. Each construction, its combination, etc. in each embodiment are illustrative, and additions, omissions, and other modifications of the construction can be made as appropriate without departing from the spirit of the present disclosure. The present disclosure is not limited by the embodiments, but only by the scope of the claims.

[0285] Examples

[0286] Hereinafter, an embodiment of the present disclosure will be described in detail based on examples.

[0287] Examples 1 to 6 and Comparative Examples 1 to 9

[0288] Prepare a mixed solution having the compounding ratios listed in Table 1 and use it as a photocurable composition. Apply the above-obtained photocurable composition to the surface of a glass substrate (slide glass) using a wire bar #12 such that the thickness after curing will be 10 μm, and then irradiate the surface with ultraviolet rays using an LED lamp at an intensity of 3000 mJ / cm 2 . Then produce a primer coat by heat-treating in an oven at 150 °C for 30 minutes.

[0289] [Evaluation]

[0290] The prepared primer coat was evaluated as follows. Table 1 shows the results. The mark "-" in Table 1 indicates that the sample was not evaluated, or the sample could not be evaluated.

[0291] (1) Adhesion test

[0292] According to JIS K 5600-5-6, scratch the primer coat at intervals of 1 mm with a cutter blade to make 100 squares in a grid pattern, attach tape, and peel the tape in the 90° direction, and visually inspect whether the surface of the coat is peeled off after the adhesion of the tape to the surface of the coat. The case where at least 90 squares adhere is evaluated as ○, and the case where less than 90 squares adhere is evaluated as ×.

[0293] (2) Appearance (shrinkage)

[0294] When visually inspecting the above primer coat, the case where uniform coating can be performed on the glass substrate is evaluated as , the case where the glass substrate can be coated is evaluated as ○, and the case where shrinkage occurs on the glass substrate is evaluated as ×.

[0295] [Table 1]

[0296]

[0297] Each of the components listed in Table 1 is described in detail below.

[0298] KR-470: Product name "KR-470" (organosiloxane having at least two alicyclic epoxy groups) manufactured by Shin-Etsu Chemical Co., Ltd.

[0299] A-1: 3’,4’-Epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (alicyclic epoxy compound)

[0300] A-2: 3,4,3’,4’-diepoxycyclohexane (alicyclic epoxide)

[0301] YX 7400N: Product name "YX 7400N" (aliphatic epoxide) manufactured by Mitsubishi Chemical Corporation

[0302] Epolite 1600: Product name "Epolite 1600", 1,6-hexanediol diglycidyl ether (aliphatic epoxide) manufactured by Kyoeisha Chemical Co., Ltd.

[0303] OXT-101: Product name "OXT-101" (oxetane compound) manufactured by Toagosei Co., Ltd.

[0304] CPI-101A: Product name "CPI-101A" (photoinitiator) manufactured by San-Apro Ltd.

[0305] Production Example 1

[0306] (Production of polyorganosilsesquioxane)

[0307] Charge 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 into a 1000-mL flask (reaction vessel) equipped with a thermometer, a stirrer, a reflux condenser, and a nitrogen inlet tube, and raise the temperature to 50°C. Within 5 minutes, add 7.74 g of a 5% potassium carbonate solution (2.8 mmol as potassium carbonate) to the resulting mixture, and then add 2800.0 mmol (50.40 g) of water over 20 minutes. No significant temperature increase occurs during the addition. Thereafter, carry out a polycondensation reaction under a nitrogen stream for 5 hours while maintaining the temperature at 50°C.

[0308] Thereafter, while cooling the reaction solution, 137.70 g of methyl isobutyl ketone and 100.60 g of 5% brine were added. The solution was transferred to a 1 L separatory funnel, and 137.70 g of methyl isobutyl ketone was added again, and the solution was washed with water. After separation, the aqueous layer was removed, and the lower layer liquid was washed with water until it became neutral. After separating the upper layer, the solvent was distilled off from the upper layer liquid under the conditions of 1 mmHg and 50 °C to obtain 75.18 g of a clear, colorless liquid product containing 23% by mass of methyl isobutyl ketone (low molecular weight polyorganosilsesquioxane containing epoxy groups: SQ1).

[0309] Analysis of the product found that the number average molecular weight was 2235, and the molecular weight distribution was 1.54. 29 The ratio [T3 form / T2 form] between the T2 form and the T3 form of the above product calculated from the Si-NMR spectrum was 11.9. The obtained epoxy-containing low molecular weight polyorganosilsesquioxane was examined by 1H-NMR and 29 Si-NMR.

[0310] The molecular weight of the product was determined under the following conditions: pump: Shimadzu LC-20AD, detector: Shodex RI-504, columns: Shodex GPC KF-602 and KF-603, column: Shodex GPC KF-G, solvent: THF, and measurement conditions: 40 °C. The ratio [T3 form / T2 form] between the T2 and T3 forms of the product was measured by 29 Si-NMR spectrometry using JEOL ECA 500 (500 MHz).

[0311] (Preparation of hard coat agent)

[0312] Each material was mixed with a low molecular weight polyorganosilsesquioxane containing epoxy groups (SQ1) such that the component ratios were those listed in Table 2 to prepare a hard coat agent.

[0313] [Table 2]

[0314]

[0315] Each of the components used in Table 2 is described in detail below.

[0316] 200PA-E5: Product name "Epoxy Ester 200PA-E5", manufactured by Kyoeisha Chemical Co., Ltd. (a compound having at least one thermopolymerizable functional group and at least one photopolymerizable functional group in one molecule)

[0317] Epolite 1600N: The product name "Epolite 1600N" (other photocationically curable compounds) manufactured by Kyoeisha Chemical Co., Ltd.

[0318] Omnirad 127: The product name "Omnirad 127", manufactured by IGM Resins B.V. (photoinitiator for free radical polymerization)

[0319] CPI-310FG: The product name "CPI-310FG", manufactured by San-Apro Ltd. (photoinitiator for cationic polymerization)

[0320] ADK STAB AO-02: The product name "ADK STAB AO-02", manufactured by ADEKA Corporation (antioxidant)

[0321] FT 602A: The product name "Ftergent 602", manufactured by NEOS Co., Ltd. (fluorine-containing photocurable resin)

[0322] KY 1203: The product name "KY 1203", manufactured by Shin-Etsu Chemical Co., Ltd. (surface conditioner)

[0323] MIBK: Methyl isobutyl ketone (solvent)

[0324] MEK: Methyl ethyl ketone (solvent)

[0325] Examples 7 to 12

[0326] On the undercoatings produced in Examples 1 to 6, the hard coating agent produced in Production Example 1 was further applied using a wire bar #24 such that the thickness of the hard coating would be 20 μm after curing, and then it was placed in an oven at 80°C for 1 minute, placed in an oven at 120°C for 2 minutes, and then irradiated with ultraviolet light using a high-pressure mercury lamp at an intensity of 300 mJ / cm 2 Thereafter, the hard coating agent was heat-treated in an oven at 120°C for 60 minutes to cure the hard coating agent, thereby preparing the laminates of Examples 7 to 12.

[0327] [Evaluation]

[0328] The above laminates were evaluated as follows. Table 3 shows the results.

[0329] (1) Adhesion test

[0330] The same adhesion test as that performed on the undercoat is carried out on the surface of the hard coat of the laminate, and the case where at least 90 squares adhere is evaluated as ○, and the case where less than 90 squares adhere is evaluated as ×.

[0331] (2) Pencil hardness

[0332] The pencil hardness of the surface of the hard coat is measured according to JIS K 5600-5-4 (750 g load).

[0333] [Table 3]

[0334]

[0335] As shown in Table 1, the photocurable composition of the present disclosure includes a first epoxy compound (which is an organosiloxane having at least two alicyclic epoxy groups), a second epoxy compound, and a third epoxy compound or an oxetane compound, and the first epoxy compound has a content of 30% to 70% by mass relative to the total amount of the composition excluding the solvent. It has been confirmed that in this configuration, the composition can be easily applied to the substrate and exhibits excellent adhesion (Examples 1 to 6). On the contrary, it has been found that if the above first epoxy compound is not included or is included in excess, the applicability to the substrate is poor (Comparative Examples 2 to 5 and 7). If the content of the first epoxy compound is small, it is possible to apply it to the substrate, but the adhesion to the substrate is poor (Comparative Example 1). In addition, in the examples where the third epoxy compound or the oxetane compound is not included, it can be easily coated on the substrate, but the adhesion to the substrate is poor (Comparative Examples 8 and 9).

[0336] Furthermore, as shown in Table 3, the laminates of the examples of the present disclosure in which the undercoat and the hard coat are laminated on the substrate exhibit high pencil hardness and excellent scratch resistance (Examples 7 and 12).

[0337] Variations attached to the invention of the present disclosure are described below.

[0338] [Appendix 1]

[0339] A photocurable composition, comprising:

[0340] A first epoxy compound, which is an organosiloxane having at least two alicyclic epoxy groups; a second epoxy compound; and a third epoxy compound or an oxetane compound,

[0341] The first epoxy compound has a content of 30% to 70% by mass relative to the total amount of the curable compounds.

[0342] [Appendix 2]

[0343] The photocurable composition according to Appendix 1, which comprises the first epoxy compound, the second epoxy compound and the oxetane compound.

[0344] [Appendix 3]

[0345] The photocurable composition according to Appendix 1 or 2, wherein the second epoxy compound has a content of 20% to 60% by mass based on the total amount of the curable compounds.

[0346] [Appendix 4]

[0347] The photocurable composition according to any one of Appendices 1 to 3, wherein the oxetane compound has a content of 5% to 25% by mass based on the total amount of the curable compounds.

[0348] [Appendix 5]

[0349] An undercoat, which is a cured product of the photocurable composition according to any one of Appendices 1 to 4.

[0350] [Appendix 6]

[0351] The undercoat according to Appendix 5, which has a thickness of 0.1 to 15 μm.

[0352] [Appendix 7]

[0353] A laminate, which comprises: a substrate laminated in sequence, an undercoat formed on at least one surface of the substrate according to Appendix 5 or 6, and a hard coat.

[0354] [Appendix 8]

[0355] The laminate according to Appendix 7, wherein the substrate is a glass substrate.

[0356] [Appendix 9]

[0357] The laminate according to Appendix 7 or 8, wherein the hard coat contains a curable polyorganosilsesquioxane resin as the curable resin.

[0358] [Appendix 10]

[0359] The laminate according to any one of Appendices 7 to 9, wherein the surface of the hard coat has a pencil hardness of 6H or more.

[0360] [Appendix 11]

[0361] The laminate according to any one of Appendices 7 to 10, wherein 100 squares are formed in a grid pattern at intervals of 1 mm on the surface of the hard coat, a tape is attached thereto, and after the tape is peeled off in the 90° direction, at least 90 squares remain.

[0362] [Appendix 12]

[0363] A display device provided with the laminate according to any one of Appendices 7 to 11.

Claims

1. A photocurable composition, comprising: A first epoxy compound, which is a silicone having at least two alicyclic epoxy groups; a second epoxy compound; and a third epoxy compound or an oxetane compound, The first epoxy compound has a content of 30% to 70% by mass based on the total amount of the curable compounds.

2. The photocurable composition according to claim 1, comprising the first epoxy compound, the second epoxy compound, and the oxetane compound.

3. The photocurable composition according to claim 1 or 2, wherein, The second epoxy compound has a content of 20% to 60% by mass based on the total amount of the curable compounds.

4. The photocurable composition according to claim 1 or 2, wherein, The oxetane compound has a content of 5% to 25% by mass based on the total amount of the curable compounds.

5. A primer coat, which is a cured product of the photocurable composition according to claim 1 or 2.

6. The primer coat according to claim 5, having a thickness of 0.1 to 15 μm.

7. A laminate, comprising: a substrate laminated in sequence, the primer coat according to claim 6 formed on at least one surface of the substrate, and a hard coat.

8. The laminate according to claim 7, wherein, The substrate is a glass substrate.

9. The laminate according to claim 7, wherein, The hard coat contains a curable polyorganosilsesquioxane resin as the curable resin.

10. The laminate according to claim 7, wherein, The surface of the hard coat has a pencil hardness of 6H or more.

11. The laminate according to claim 7, wherein, After making 100 squares in a grid pattern at 1 mm intervals on the surface of the hard coat, attaching a tape thereto, and peeling the tape in the 90° direction, at least 90 squares remain.

12. A display device provided with the laminate according to claim 7.

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