Active energy ray curable resin composition, cured product and optical sheet

Abstract

To provide an optical sheet and a cured product which can suppress attachment of moisture by exhibiting a water contact angle while having a high refractive index, high abrasion resistance and high self-curing property, and an active energy ray-curable resin composition that can be used in them.SOLUTION: An active energy ray-curable resin composition contains a polymerizable compound (A), a photopolymerization initiator (B) and a leveling agent (C), wherein the polymerizable compound (A) contains a polymerizable compound (A1) having an alkylene oxide chain in the structure and a polymerizable compound (A2) having an SP value of 8.88 or less, and the polymerizable compound (A1) is contained so that a content of an alkylene oxide chain in the compound structure is 0.6 mmol / g or more in the total amount of the composition.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an active energy ray-curable resin composition for use in optical articles, a cured product obtained by curing the composition, and an optical sheet made of the cured product. [Background technology]

[0002] In recent years, with the rapid development of display technologies such as liquid crystal display devices, there has been an increasing demand for new functions and high quality for sheet-like or film-like optical members used in these devices. One example of such an optical member is a prism sheet used as a light collecting film for a backlight. Prism sheets have the effect of improving the brightness on the front side of a display by refracting backlight with the fine uneven structure on the surface. In recent years, there has been a demand for prism sheets to have a high refractive index to further improve display brightness, as well as excellent abrasion resistance and self-healing properties.

[0003] For example, Patent Document 1 discloses an active energy ray-curable resin composition for optical articles that contains a fluorene-based (meth)acrylate and phenoxybenzyl acrylate, and discloses that a cured product obtained by curing the composition has a high refractive index, excellent scratch resistance, and suitable self-healing properties. Furthermore, Patent Document 2 discloses a resin composition for optical materials that contains a reaction product of a bisphenol A type epoxy resin and acrylic acid, a phenylphenoxyalkyl (meth)acrylate or the like, a specific mono- or di-functional chain (meth)acrylate compound, and a photopolymerization initiator, and discloses that the composition is excellent in refractive index, hardness, restorability, etc. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2018 / 070256 [Patent Document 2] JP 2012-219205 A Summary of the Invention [Problem to be solved by the invention]

[0005] Recently, in order to improve durability in various environments, in addition to the high refractive index, abrasion resistance (scratch resistance), and self-healing properties mentioned above, there has been a growing demand for hydrophobic properties in prism sheets. Conventional prism sheets that do not exhibit hydrophobic properties tend to attract moisture to the surface of the prism sheet due to temperature changes during transportation or use of the terminal, and water spots occur after the droplets dry, which can lead to reduced yields and reduced functionality of the prism sheet.

[0006] An object of the present invention is to provide an optical sheet and cured product that have a high refractive index, high abrasion resistance, and high self-healing property, while exhibiting a water contact angle to suppress adhesion of moisture, as well as an active energy ray-curable resin composition that can be used therefor. [Means for solving the problem]

[0007] That is, the present invention provides the following inventions. (1) An active energy ray-curable resin composition comprising a polymerizable compound (A), a photopolymerization initiator (B) and a leveling agent (C), characterized in that the polymerizable compound (A) comprises a polymerizable compound (A1) having an alkylene oxide chain in its structure and a polymerizable compound (A2) having an SP value of 8.88 or less, and the polymerizable compound (A1) is contained such that the content of the alkylene oxide chain in the compound structure is 0.6 mmol / g or more in the total amount of the composition. (2) The active energy ray-curable resin composition according to (1), comprising, as the polymerizable compound (A2), a compound represented by the following formula (a2-1):

[0008] [ka]

[0009] (In the formula, R 21 is a hydrogen atom or a methyl group, and Q 21 is a single bond or a divalent linking group, R 22 is an alkyl group having 14 to 22 carbon atoms. (3) The active energy ray-curable resin composition according to (1) or (2), comprising, as the polymerizable compound (A1), a compound represented by the following formula (a1-1):

[0010] [ka]

[0011] (In the formula, R 1 and R 2 each independently represents a hydrogen atom or a methyl group; X 1 and X 2 each independently represents an alkylene group having 2 or 3 carbon atoms, m and n each independently represent an integer of 1 or more, and m+n is 20 or more. (4) The active energy ray-curable resin composition according to any one of (1) to (3), comprising, as the polymerizable compound (A1), a compound represented by the following formula (a1-2):

[0012] [ka]

[0013] (In the formula, R 11 represents a hydrogen atom or a methyl group, and X 12 represents an alkylene group having 2 or 3 carbon atoms, and p represents an integer of 1 or more. (5) The active energy ray-curable resin composition according to any one of (1) to (4), wherein the proportion of the polymerizable compound (A2) in the active energy ray-polymerizable compound (A) is 0.1 to 30 mass %. (6) The active energy ray-curable resin composition according to any one of (1) to (5), wherein the proportion of the polymerizable compound (A1) in the active energy ray-polymerizable compound (A) is 30 to 95 mass %. (7) A cured product of the active energy ray-curable resin composition according to any one of (1) to (6), characterized in that the cured product has a refractive index of 1.54 or more. (8) An optical sheet having a layer made of the cured product of (7). Effect of the Invention

[0014] The cured product and optical sheet obtained by curing the active energy ray curable resin composition of the present invention can satisfy the conventionally required characteristics of high refractive index, high abrasion resistance, and suitable self-healing property by using a polymerizable compound having a certain amount or more of alkylene oxide chains in the structure, a hydrophobic polymerizable compound having a certain or less SP value, a photopolymerization initiator, and a leveling agent in combination, and can also exhibit a good water contact angle. Therefore, the active energy ray curable resin composition of the present invention can be suitably applied to various optical products, such as prism sheets used in displays such as liquid crystal display devices, lenticular lens sheets used in stereoscopic photographs and projection screens, Fresnel lens sheets used in condenser lenses of overhead projectors, and diffraction gratings used in color filters. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] <Active energy ray polymerizable compound> The active energy ray-curable resin composition of the present invention (hereinafter sometimes simply referred to as "composition") contains a polymerizable compound (A), a photopolymerization initiator (B) and a leveling agent (C).

[0016] [Polymerizable compound (A)] The polymerizable compound (A) (hereinafter sometimes referred to as "component (A)" or "compound (A)") contains a polymerizable compound (A1) having an alkylene oxide chain in its structure, and a polymerizable compound (A2) having an SP value of 8.88 or less.

[0017] (Polymerizable compound (A1)) The polymerizable compound (A1) (hereinafter sometimes referred to as "component (A1)" or "compound (A1)") has an alkylene oxide chain in its structure. When compound (A1) has a certain amount or more of alkylene oxide chain, the abrasion resistance and self-healing property of the cured composition are improved. The alkylene oxide chain is "-O-(CH 2 ) p -structure" (p is an integer of 1 to 10, preferably an integer of 2 to 5), is not particularly limited, and is preferably an ethylene oxide chain, a propylene oxide chain, a butylene oxide chain, or a combination thereof, more preferably an ethylene oxide chain, a propylene oxide chain, or a combination thereof, and particularly preferably an ethylene oxide chain.

[0018] The component (A1) is a polymerizable compound having a polymerizable group in its structure that can be polymerized by active energy rays. Examples of the polymerizable group include a (meth)acryloyl group, a (meth)acrylamide group, a vinyl group, a vinyl ether group, a vinyl ester group, a maleimide group, and an epoxy group. In this specification, the terms "(meth)acryloyl group" and "(meth)acrylamide group" are generic terms including an acryloyl group and a methacryloyl group, an acrylamide group and a methacrylamide group, respectively. In addition, the term "(meth)acrylate" is a generic term including an acrylate and a methacrylate, respectively. Among these, the polymerizable group is particularly preferably a (meth)acryloyl group because of its high reactivity upon irradiation with active energy rays.

[0019] Examples of the component (A1) include alkylene oxide group-modified poly(meth)acrylates obtained by reacting a polyol having an alkylene oxide group with (meth)acrylic acid, such as ethylene oxide-modified poly(meth)acrylate of trimethylolpropane, propylene oxide-modified poly(meth)acrylate of trimethylolpropane, ethylene oxide-modified poly(meth)acrylate of ditrimethylolpropane, propylene oxide-modified poly(meth)acrylate of ditrimethylolpropane, ethylene oxide-modified poly(meth)acrylate of pentaerythritol, propylene oxide-modified poly(meth)acrylate of pentaerythritol, ethylene oxide-modified poly(meth)acrylate of dipentaerythritol, and ethylene oxide-modified poly(meth)acrylate of tetramethylolmethane; Examples of the alkylene oxide-modified poly(meth)acrylate oligomer include modified epoxy poly(meth)acrylate, propylene oxide group-modified epoxy poly(meth)acrylate, ethylene oxide group-modified urethane poly(meth)acrylate, propylene oxide group-modified urethane poly(meth)acrylate, ethylene oxide group-modified polyester poly(meth)acrylate, and propylene oxide group-modified polyester poly(meth)acrylate; and (meth)acrylates of alkylene oxide adducts of bisphenol, such as di(meth)acrylate of an ethylene oxide adduct of bisphenol A, di(meth)acrylate of a propylene oxide adduct of bisphenol A, di(meth)acrylate of an ethylene oxide adduct of bisphenol F, and di(meth)acrylate of a propylene oxide adduct of bisphenol F.

[0020] Moreover, preferred compounds for the component (A1) include compounds represented by the following formula (a1-1).

[0021] [ka]

[0022] In the formula, R 1 and R2 R each independently represents a hydrogen atom or a methyl group, and it is preferable that at least one of them is a hydrogen atom. 1 and R 2 and may be the same group or different groups. X 1 and X 2 Each of X independently represents an alkylene group having 2 or 3 carbon atoms. When the number of carbon atoms is 2, the moiety is an ethylene oxide chain, and when the number of carbon atoms is 3, the moiety is a propylene oxide chain. 1 and X 2 may be the same group or different groups. m and n each independently represent an integer of 1 or more, and m+n is 20 or more. By making m+n 20 or more, excellent wear resistance and self-healing properties can be achieved. m+n is preferably 20 to 30, and more preferably 20 to 25. When m or n is 2 or more, multiple Xs 1 Or X 2 may be the same or different, but from the viewpoint of ease of synthesis, 1 Or X 2 are preferably the same, and all X 1 Also X 2 It is particularly preferred that are the same.

[0023] Furthermore, the component (A1) is preferably a compound represented by the following formula (a1-2):

[0024] [ka]

[0025] In the formula, R 11 represents a hydrogen atom or a methyl group, and is preferably a hydrogen atom. X 12 represents an alkylene group having 2 or 3 carbon atoms, and is preferably ethylene having 2 carbon atoms; p represents an integer of 1 or more, preferably an integer of 1 to 5, more preferably an integer of 1 to 3, and more preferably 1 or 2; When p is 2 or more, multiple X 12 may be the same or different, but multiple X 12 are preferably all the same. The compound represented by formula (a1-2) has a biphenyl structure, and thereby contributes to increasing the refractive index of the cured product obtained by curing the composition.

[0026] In the composition of the present invention, the component (A1) is contained in such a content that the content of the alkylene oxide chain in the compound structure is 0.6 mmol / g or more in the total amount of the composition. The content of the alkylene oxide chain is preferably 0.6 to 1.6 mmol / g, more preferably 0.6 to 1.2 mmol / g, and even more preferably 0.6 to 1.0 mmol / g. By making it 0.6 mmol / g or more, good self-healing properties can be obtained, and by making it the upper limit value or less, it becomes possible to develop a water contact angle.

[0027] The content of the (A1) component itself is not particularly limited as long as it satisfies the above-mentioned alkylene oxide chain content, but is preferably 10 to 98 mass % of the total amount of the composition, more preferably 10 to 55 mass %, even more preferably 10 to 45 mass %, and particularly preferably 20 to 35 mass %. The content of the component (A1) in the component (A) is preferably 30 to 99.9 mass %, more preferably 60 to 98 mass %, even more preferably 70 to 98 mass %, and particularly preferably 80 to 95 mass %.

[0028] (Polymerizable compound (A2)) The polymerizable compound (A2) (hereinafter sometimes referred to as "component (A2)" or "compound (A2)") does not fall under the category of component (A1) and is a polymerizable compound having an SP value of 8.88 or less. By using compound (A2) having an SP value of 8.88 or less, it is possible to develop a water contact angle on the surface after curing. The SP value is one of the parameters that indicates the affinity between raw materials, and in the present invention, was calculated by the Fedors method as an index of hydrophobicity.

[0029] The component (A2) is a polymerizable compound having a polymerizable group in its structure that can be polymerized by active energy rays. As the polymerizable group, the same ones as those explained for the component (A1) can be used, and the component (A2) is preferably a (meth)acrylate having a (meth)acryloyl group.

[0030] When the component (A2) is a (meth)acrylate, the compound represented by the following formula (a2-1) is preferable.

[0031] [ka]

[0032] In the formula, R 21 is a hydrogen atom or a methyl group, and is preferably a hydrogen atom. Q 21 is a single bond or a divalent linking group. Examples of the divalent linking group include a substituted alkylene group, an optionally substituted arylene group, an optionally substituted divalent heterocyclic group, an optionally substituted alkenylene group, or a combination of these with -O-, -S-, -CO-, -CO 2 A divalent linking group formed by combining R 22 Since Q is an alkyl group, 21 is preferably not an unsubstituted alkylene group. Among them, Q 21 As the group, a single bond is preferable.

[0033] R 22 is an alkyl group having 14 to 22 carbon atoms. The compound represented by formula (a2-1) is 22 By using such a hydrophobic compound having a relatively long-chain alkyl group, the SP value of component (A2) becomes 8.88 or less, making it possible to impart a water contact angle to the composition of the present invention. R 22 The number of carbon atoms in the alkyl group is preferably 16 to 20, more preferably 18 to 20, and particularly preferably 16. R 22The alkyl group is chain-like and may be either a straight-chain alkyl group or a branched-chain alkyl group, but a straight-chain alkyl group is preferred because it allows the effects of the present invention to be more pronounced. In the case of a branched-chain alkyl group, the main chain preferably has 14 or more carbon atoms.

[0034] The content of the component (A2) in the component (A) is preferably 0.1 to 30 mass %, more preferably 0.3 to 20 mass %, even more preferably 0.5 to 10 mass %, and particularly preferably 1 to 5 mass %.

[0035] (Other polymerizable compounds) The component (A) may contain a polymerizable compound other than the components (A1) and (A2). As the other polymerizable compound, a monofunctional compound having one polymerizable group or a polyfunctional compound having two or more polymerizable groups, which does not fall under the category of the components (A1) to (A2), can be appropriately used.

[0036] Examples of the monofunctional compound include n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, benzyl (meth)acrylate, phenylbenzyl (meth)acrylate, phenoxyethyl (meth)acrylate, glycidyl (meth)acrylate, morpholine (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and the like. Monofunctional (meth)acrylates such as acrylate, 2-methoxyethyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, caprolactone-modified tetrahydrofurfuryl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, cyclohexylmethyl (meth)acrylate, cyclohexylethyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentanyloxyethyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and dicyclopentenyloxyethyl (meth)acrylate can be preferably used. These monofunctional (meth)acrylates may be used alone or in combination.

[0037] The monofunctional compound preferably has a viscosity of 300 mPa·s or less at 25° C., more preferably 200 mPa·s or less, and has a refractive index of preferably 1.4 or more, more preferably 1.5 or more, and even more preferably 1.55 or more, at 25° C. and 589 nm.

[0038] As the monofunctional compound, phenylbenzyl acrylate represented by the following formula (4) is preferred because it is easy to improve the refractive index of the obtained cured product while favorably maintaining the viscosity of the composition.

[0039] [ka]

[0040] When the compound represented by formula (4) is used, the content of the compound represented by formula (4) in the active energy ray-polymerizable compound (A) contained in the active energy ray-curable resin composition for optical articles of the present invention is preferably 5 to 30 mass %, and more preferably 10 to 20 mass %.

[0041] Examples of polyfunctional compounds include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, tetrabutylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, dicyclopentanyl di(meth)acrylate, Examples of polyfunctional (meth)acrylates include glycerol di(meth)acrylate, neopentyl glycol hydroxypivalic acid ester di(meth)acrylate, caprolactone-modified hydroxypivalic acid neopentyl glycol di(meth)acrylate, tetrabromobisphenol A di(meth)acrylate, hydropivalaldehyde-modified trimethylolpropane di(meth)acrylate, 1,4-cyclohexanedimethanol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, glycerol tri(meth)acrylate, alkyl-modified dipentaerythritol tri(meth)acrylate, and ditrimethylolpropane tetra(meth)acrylate. As the polyfunctional (meth)acrylate, for example, a polyfunctional oligomer having an acryloyl group, such as urethane (meth)acrylate, polyester (meth)acrylate, or epoxy (meth)acrylate, can also be used. These monofunctional compounds and polyfunctional compounds may be used alone or in combination of two or more.

[0042] [Photopolymerization initiator (B)] The photopolymerization initiator (B) (hereinafter, sometimes referred to as "component (B)") is not particularly limited, and various known and commonly used initiators can be used. In the production of an article using the composition of the present invention, active energy rays such as ultraviolet rays are often irradiated through the surface of a transparent substrate that serves as a support. Therefore, component (B) is preferably an initiator that has light absorption ability in the long wavelength region, and for example, a photopolymerization initiator that exhibits photoinitiating ability when ultraviolet rays are in the range of 360 to 450 nm is preferred.

[0043] Examples of the component (B) include benzophenones such as benzophenone, 3,3'-dimethyl-4-methoxybenzophenone, 4,4'-bisdimethylaminobenzophenone, 4,4'-bisdiethylaminobenzophenone, 4,4'-dichlorobenzophenone, Michler's ketone, and 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone; xanthones and thioxanthones such as xanthone, thioxanthone, 2-methylthioxanthone, 2-chlorothioxanthone, and 2,4-diethylthioxanthone; acyloin ethers such as benzoin, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether; α-diketones such as benzil and diacetyl; Sulfides such as tetramethylthiuram disulfide and p-tolyl disulfide; Benzoic acids such as 4-dimethylaminobenzoic acid and ethyl 4-dimethylaminobenzoate; 3,3′-Carbonyl-bis(7-diethylamino)coumarin, 1-hydroxycyclohexyl phenyl ketone, 2,2′-dimethoxy-1,2-diphenylethan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2 ,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 1-(4-dodecylphenyl)-2-hydroxy-2-methylpropan-1-one, 4-benzoyl-4'-methyldimethylsulfide, 2,2'-diethoxyacetophenone, benzyl dimethylketal, benzyl-β-methoxyethyl acetal, o-benzoyl methyl benzoate, bis(4-dimethylaminophenyl)ketone, p-dimethylaminoacetophenone, α,α-dichloro-4-phenoxyacetophenone, pentyl-4-dimethylaminobenzoate, 2-(o-chlorophenyl)-4,5-diphenylimidazo triphenyl dimer, 2,4-bis-trichloromethyl-6-[di-(ethoxycarbonylmethyl)amino]phenyl-S-triazine, 2,4-bis-trichloromethyl-6-(4-ethoxy)phenyl-S-triazine, 2,4-bis-trichloromethyl-6-(3-bromo-4-ethoxy)phenyl-S-triazineanthraquinone, 2-t-butylanthraquinone, 2-amylanthraquinone, β-chloroanthraquinone, and the like.

[0044] The component (B) may be used alone or in combination of two or more types.

[0045] There are no particular restrictions on the amount of the (B) component used, but in order to obtain favorable curability and favorable abrasion resistance and self-healing properties of the resulting cured product, the amount is preferably 0.05 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, and even more preferably 0.5 to 5 parts by mass, per 100 parts by mass of the (A) component.

[0046] [Leveling agent (C)] The leveling agent (surface conditioner, hereinafter sometimes referred to as "component (C)") adjusts the condition of the surface layer of the coating film formed by the composition of the present invention, and the inclusion of the leveling agent can improve the abrasion resistance after curing. On the other hand, the leveling agent reduces the surface tension of the coating film and increases the wettability of the coating film, so that the use of the leveling agent results in a state in which the water contact angle is not expressed. In the present invention, this problem is solved by the combined use of the above-mentioned component (A2), so that the water contact angle can be expressed even when component (C) is used, and at the same time, good abrasion resistance and self-healing properties can be achieved.

[0047] Examples of the component (C) include acrylic leveling agents, silicon leveling agents, fluorine leveling agents, vinyl leveling agents, etc. These leveling agents may be used alone or in combination of two or more.

[0048] Among these surface conditioners, from the viewpoint of improving self-healing properties, a silicon-based leveling agent is preferable. Examples of the silicon-based leveling agent include the BYK series manufactured by BYK Japan.

[0049] The content of (C) is preferably 0.005 to 10 parts by mass, more preferably 0.01 to 5 parts by mass, and even more preferably 0.1 to 1 part by mass, per 100 parts by mass of the component (A).

[0050] The active energy ray-curable resin composition of the present invention may contain, as necessary, other components as additives other than the above components (A) to (C). The additives are not particularly limited as long as they do not fall under the components (A) to (C), and examples of the additives include photosensitizers, ultraviolet absorbers, antioxidants, silicon-based additives, fluorine-based additives, rheology control agents, defoamers, mold release agents, silane coupling agents, antistatic agents, antifogging agents, colorants, and inorganic fillers.

[0051] The active energy ray curable resin composition for optical articles of the present invention may contain a solvent as necessary, but a lower solvent content is preferable because it is possible to obtain an active energy ray curable resin composition for optical articles that is less likely to pollute the working environment. Specifically, the solvent content in the active energy ray curable resin composition for optical articles of the present invention is preferably 1 mass% or less, and is preferably substantially free of solvent.

[0052] Examples of the photosensitizer include amines, ureas, sulfur-containing compounds, phosphorus-containing compounds, chlorine-containing compounds, nitriles, and other nitrogen-containing compounds.

[0053] Examples of the ultraviolet absorber include triazine derivatives such as 2-[4-{(2-hydroxy-3-dodecyloxypropyl)oxy}-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine and 2-[4-{(2-hydroxy-3-tridecyloxypropyl)oxy}-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2'-xanthenecarboxy-5'-methylphenyl)benzotriazole, 2-(2'-o-nitrobenzyloxy-5'-methylphenyl)benzotriazole, 2-xanthenecarboxy-4-dodecyloxybenzophenone, and 2-o-nitrobenzyloxy-4-dodecyloxybenzophenone.

[0054] Examples of the antioxidant include hindered phenol-based antioxidants, hindered amine-based antioxidants, organic sulfur-based antioxidants, and phosphate-based antioxidants.

[0055] Examples of the silicon-based additive include polyorganosiloxanes having an alkyl group or a phenyl group, such as dimethylpolysiloxane, methylphenylpolysiloxane, cyclic dimethylpolysiloxane, methylhydrogenpolysiloxane, polyether-modified dimethylpolysiloxane copolymer, polyester-modified dimethylpolysiloxane copolymer, fluorine-modified dimethylpolysiloxane copolymer, and amino-modified dimethylpolysiloxane copolymer.

[0056] The inorganic filler (inorganic nanoparticles) preferably has a high refractive index, and includes alumina, zirconia, titania, their compounds, or their mixed oxides, or their metal oxides. These inorganic nanoparticles have a higher refractive index than general organic materials, so they are effective as a means of increasing the refractive index of the cured product, but it is necessary to consider the balance between the strength of the molded product and the adhesion to the substrate, and the amount of inorganic nanoparticles is practically in the range of 20 to 60 mass% relative to the total amount of component (A) and inorganic nanoparticles. Among them, in order to have both a high refractive index and self-healing properties, 30 to 50 mass% is more preferable.

[0057] The amount of each of the above-mentioned additives used is not particularly limited as long as it is within a range in which the additives can fully exert their effects and do not inhibit curing by active energy rays, but the amount of each additive used is preferably 0.05 to 20 parts by mass, and more preferably 0.1 to 10 parts by mass, per 100 parts by weight of the composition.

[0058] The composition of the present invention may contain a solvent if necessary, but from the viewpoint of preventing pollution of the working environment, the content of the solvent is preferably small. Specifically, the content of the solvent in the composition is preferably 1% by mass or less.

[0059] The active energy ray-curable resin composition of the present invention has a viscosity at 25° C. of preferably 50 to 5000 mPa·s, more preferably 100 to 2000 mPa·s, since it is easy to apply and mold into a desired shape and thickness in various optical article applications. In particular, when applied to prism sheet applications, it is preferable that the viscosity is 50 to 800 mPa·s, since it is easy to apply uniformly to a prism sheet matrix and easy to replicate a matrix having a fine uneven structure (enabling faster line speeds). It should be noted that compositions having a viscosity outside the above range can also be used by adopting a method such as adjusting the viscosity by controlling the temperature of the composition.

[0060] The acid value of the active energy ray-curable resin composition of the present invention (the number of milligrams of potassium hydroxide required to neutralize the acid content present in 1 g of a sample based on a specified method) is preferably 5.0 mgKOH / g or less because it is an active energy ray-curable resin composition for optical articles that can give a cured product having excellent environmental stability, and is particularly preferably 0 mgKOH / g to 3.0 mgKOH / g.

[0061] <Cured product> The active energy ray curable resin composition of the present invention can be applied to a substrate or molded according to the intended use, and then irradiated with active energy rays to form a cured product. Examples of active energy rays include electron beams, ultraviolet rays, and visible light. When electron beams are used as active energy rays, the curable resin composition of the present invention can be cured using electron beam generators such as a Cockcroft-Walton accelerator, a Van de Graaff electron accelerator, a resonant transformer accelerator, an insulating core transformer type, a dynamitron type, a linear filament type, and a high frequency type. When ultraviolet rays are used as active energy rays, the composition can be cured by irradiation with mercury lamps such as ultra-high pressure mercury lamps, high pressure mercury lamps, and low pressure mercury lamps, xenon lamps, carbon arcs, metal high lamps, and high output LED-UV lamps.

[0062] The cured product of the active energy ray-curable resin composition of the present invention preferably has a refractive index of 1.50 or more, more preferably 1.54 or more, even more preferably 1.55 or more, and particularly preferably 1.56 or more. The cured product has a high refractive index and suitable scratch resistance, etc., and therefore can be suitably applied to various optical articles.

[0063] The hardness of the cured product of the present invention may be appropriately designed depending on various applications, but for example, when used as a prism sheet, the elastic modulus at 25° C. is preferably 5 to 500 MPa, and more preferably 10 to 100 MPa. By setting the elastic modulus within this range, a good balance between mechanical strength and toughness (elongation) is achieved, and the restoring force required for self-healing properties is easily expressed. The elastic modulus is a value obtained by dynamic viscoelasticity measurement using a viscoelasticity measuring device "RSAII" manufactured by Rheometoric Scientific Corporation under the measurement conditions of a temperature rise rate of 3°C / min and a frequency of 3.5 Hz.

[0064] The cured product of the present invention preferably has a glass transition temperature Tg of 40° C. or less, more preferably 30° C. or less, and particularly preferably 25° C. or less. By setting the glass transition temperature in this range, it becomes easier to have both a high refractive index and good self-healing properties. The lower limit of Tg is not particularly limited, but is preferably 5° C. or more, more preferably 10° C. or more, and particularly preferably 15° C. or more. In the present invention, the Tg can be easily adjusted to the range by using the components (A) to (C) and blending them in suitable ranges. The glass transition temperature is a value obtained by reading, as Tg, the temperature at the peak position of tan δ, which is expressed by the ratio of the storage modulus E' to the complex modulus E'' obtained by viscoelasticity measurement.

[0065] [Optical sheet] The optical sheet of the present invention is an optical sheet having a layer made of a cured product of the active energy ray-curable resin composition. The optical sheet is an optical sheet in which prisms or lenses made of the cured product are laminated on a transparent resin film, and specific examples of the optical sheet include a prism sheet used in displays such as liquid crystal display devices, a lenticular lens sheet used in stereoscopic photographs and projection screens, a Fresnel lens sheet used in condenser lenses for overhead projectors, and a diffraction grating used in color filters.

[0066] Examples of the manufacturing method of these optical sheets include a method in which the active energy ray curable resin composition is filled into a matrix having a fine shape required for various applications, a substrate is pressurized and laminated to adhere to the filled resin composition so that air does not get mixed in, the resin composition is cured by irradiating active energy rays such as ultraviolet rays from the substrate side, and then the optical sheet is released from the matrix. Also included is a continuous manufacturing method in which the resin composition is continuously filled into a roll-shaped matrix, a substrate is continuously adhered to the filled resin composition so that air does not get mixed in, the resin composition is cured by irradiating active energy rays such as ultraviolet rays from the substrate side, and then the optical sheet is released from the roll-shaped matrix.

[0067] The substrate used to form the optical sheet may be a transparent substrate in the form of a film, sheet, or plate. The material of the substrate may be appropriately selected depending on the application, and examples thereof include polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), triacetyl cellulose, polycarbonate resins, acrylic resins such as methyl methacrylate copolymers, styrene resins, polysulfone resins, polyethersulfone resins, polycarbonate resins, vinyl chloride resins, and polymethacrylimide resins. Inorganic substrates such as glass substrates may also be used.

[0068] The active energy ray-curable resin composition of the present invention can be suitably applied to a prism sheet used in various displays, among various optical sheets. The prism sheet has a plurality of fine prism-shaped portions on one side of a sheet-like molded product, and is usually disposed on the back side (light source side) of a liquid crystal display element with the prism surface facing the element.

[0069] The prism sheet is a sheet having a prism layer made of a cured product of the active energy ray-curable resin composition on a transparent film, and the shape of the prism layer is such that the prism apex angle θ is preferably 70 to 110° from the viewpoint of excellent light-collecting ability and improved brightness, more preferably 75 to 100°, and particularly preferably 80 to 95°.

[0070] The pitch of the prism is preferably 100 μm or less, and particularly preferably 70 μm or less, from the viewpoints of preventing the occurrence of moire patterns on the screen and improving the definition of the screen. The height of the unevenness of the prism is determined by the prism apex angle θ and the value of the prism pitch, and is preferably 50 μm or less. Furthermore, the thickness of the prism lens sheet is preferably thicker from the viewpoint of strength, but is preferably thinner from an optical viewpoint in order to suppress light absorption, and is preferably 50 μm to 1000 μm from the viewpoint of the balance between these. EXAMPLES

[0071] The present invention will be described in more detail below with reference to examples and comparative examples. In the examples, all parts and percentages are by weight unless otherwise specified. The characteristics and the like in the examples and comparative examples were measured and evaluated as follows.

[0072] [Table 1]

[0073] [Table 2]

[0074] <Self-healing property> A prism matrix with a prism pitch of 50 μm, a prism height of 25 μm, and an apex angle of 90° was filled with the resin compositions prepared in the Examples and Comparative Examples, a 125 μm PET film was placed on top, and the pieces were laminated together while applying pressure with a roller. The resin composition was then cured from the PET film side with a high-pressure mercury lamp at an integrated light dose of 400 mJ / cm2 to produce a prism sheet. The resulting prism sheet was scratched about 3 cm with an awl, and the time it took for the scratches (lines) to disappear was visually observed and evaluated according to the following criteria. 5: Instant recovery (scratches disappear) 4: Recovery within 10 seconds (scratches disappear) 3: Recovery within 1 minute (scratches disappear) 2: Recovery within 5 minutes (scratches disappear) 1: Restoration in 15 minutes or more (scratches disappear) 0: Do not restore

[0075] <Wear resistance> A diffusion film cut into a circle with a diameter of 1 cm was placed on the prism sheet obtained in the same manner as above, and a load of 400 g was applied, and the film was rubbed back and forth 40 times over a distance of 10 cm using an abrasion resistance tester (IMC-15FA type) manufactured by Imoto Manufacturing Co., Ltd., and the band-like scratches on the surface were evaluated based on the area of ​​the scratched parts. The evaluation was carried out indoors at 23°C, and judged according to the following criteria, with A or above being considered a pass. A: The area of ​​the scratch is 5cm 2 below B: The area of ​​the scratch is 5cm 2 Larger than 7cm 2 below C: The area of ​​the scratch is 7cm 2 Greater than

[0076] <Water contact angle> Onto the prism sheet obtained in the same manner as above, 50 μl of ion-exchanged water was extruded from a syringe, and the water contact angle was measured using a water contact angle meter (DMo-501 type) manufactured by Kyowa Interface Science Co., Ltd. The evaluation was carried out indoors at 23°C, and the observation was made from a direction parallel to the ridge of the prism sheet, and the measurement results were evaluated as follows. B or higher is considered to be a pass. A: The water contact angle is 50° or more 1 second after the drop is applied, and the water contact angle retention rate is 80% or more after 5 minutes. B: The water contact angle is 50° or more 1 second after the drop is applied, and the water contact angle retention rate after 5 minutes is less than 80%. C: The water contact angle 1 second after the drop is 30° or more and less than 50°, and the water contact angle retention rate after 5 minutes is Over 80% D: The water contact angle 1 second after the drop is 30° or more and less than 50°, and the water contact angle retention rate after 5 minutes is Less than 80% E: Water contact angle 1 second after droplet arrival is less than 30°

[0077] (Examples 1 to 4, Comparative Examples 1 to 5) The compounds were melt-mixed in the ratio shown in the table below to prepare a resin composition. The alkylene oxide content (mmol / g) of the polymerizable compound (A1) is shown in the table as "alkylene oxide content". The above evaluations were carried out using the obtained resin compositions. Note that the numerical values ​​of the composition blend amounts in the tables are in mass %.

[0078] [Table 1]

[0079] [Table 2]

[0080] The compounds listed in the above table are as follows. A1-1: Ethylene oxide-modified bisphenol A diacrylate (MIRAMER M-2200 manufactured by MIWON Co., Ltd., R 1 and R 2is a hydrogen atom · X 1 and X 2 Compound with ethylene group m+n=20, ethylene oxide modification amount 20 moles) A1-2: Ethylene oxide-modified bisphenol A diacrylate (MIRAMER M-2100 manufactured by MIWON Co., Ltd., R 1 and R 2 is a hydrogen atom · X 1 and X 2 Compound with ethylene group m+n=10, ethylene oxide modification amount 10 moles) A1-3: ethylene oxide modified acrylate of o-phenylphenol (MIRAMER M-1142 manufactured by MIWON Co., Ltd., R 11 is a hydrogen atom · X 12 Compound with ethylene group · p = 1, ethylene oxide modification amount 1 mol) A2-1: Stearyl acrylate (SP value: 8.80) (KPX Corporation, "KOMERATE A189"; R 21 is a hydrogen atom ·Q 21 is a single bond · R 22 is a straight-chain compound with 18 carbon atoms) A2-2: Cetyl acrylate (SP value: 8.83) (KPX Corporation, "KOMERATE A169"; R in the formula (a2-1) 21 is a hydrogen atom ·Q 21 is a single bond · R 22 is a straight-chain compound with 16 carbon atoms) A2-3: Dodecyl acrylate (SP value: 8.89) (KPX "KOMERATE A129"; R in the formula (a2-1) 21 is a hydrogen atom ·Q 21 is a single bond · R 22 is a straight-chain compound with 12 carbon atoms) A2-4: Behenyl acrylate (SP value: 8.77) (KPX Corporation, "KOMERATE A229"; R 21 is a hydrogen atom ·Q 21 is a single bond · R 22 is a straight-chain compound with 22 carbon atoms) A2-5: Stearyl methacrylate (SP value: 8.74) (KPX Corporation, "KOMERATE A189M"; R 21 is a methyl group ·Q 21 is a single bond · R 22 is a straight-chain compound with 18 carbon atoms) A2-6: isobornyl acrylate (SP value: 9.93) (manufactured by Osaka Organic Chemical Industry Co., Ltd., "IBXA"; R 21 is a hydrogen atom · R 22 Or Q 21 (Compounds in which the part corresponding to the compound is an isobornyl group) A2-7: Tricyclodecane dimethanol diacrylate (SP value: 11.30) (KPX Corporation, "KOMERATE D0013"; R 21 is a hydrogen atom · R 22 Or Q 21 (a compound having a tricyclodecane skeleton with a monoacrylate in the portion corresponding to A2-8: Cyclohexyl acrylate (SP value: 10.04) ("Viscoat #155" manufactured by Osaka Organic Chemical Industry Co., Ltd., R 21 is a hydrogen atom · R 22 Or Q 21 (Compounds in which the part corresponding to B1: 1-Hydroxycyclohexyl phenyl ketone ("OMNIRAD184" manufactured by IGM RESINS BV) C1: Polyether-modified polydimethylsiloxane (BYK-333, manufactured by BYK Japan)

[0081] As is clear from the above results, it was confirmed that the active energy ray-curable resin composition of the present invention has an excellent balance between the expression of a water contact angle and self-healing properties and abrasion resistance. On the other hand, it was confirmed that Comparative Example 1, in which the alkylene oxide content was less than 0.6 mmol / g, was inferior in self-healing property and abrasion resistance, and Comparative Examples 2 to 5, which did not contain a polymerizable compound with an SP value of 8.88 or less, did not exhibit a water contact angle and would not be able to suppress adhesion of water. [Industrial Applicability]

[0082] As described above, the active energy ray-curable resin composition of the present invention can be suitably used for various optical members including a prism sheet and the like.

Claims

1. An active energy ray-curable resin composition comprising a polymerizable compound (A), a photopolymerization initiator (B) and a leveling agent (C), the polymerizable compound (A) contains a polymerizable compound (A1) having an alkylene oxide chain in its structure, and a polymerizable compound (A2) having an SP value of 8.88 (cal / cm 3 ) 1 / 2 or less; the polymerizable compound (A1) is contained in such an amount that the content of the alkylene oxide chain in the compound structure is 6.0 mmol / g or more based on the total amount of the composition; The polymerizable compound (A1) contains a compound represented by the following formula (a1-1): 【Chemistry 1】 (In the formula, R 1 and R 2 each independently represent a hydrogen atom or a methyl group, X 1 and X 2 each independently represent an alkylene group having 2 or 3 carbon atoms, m and n each independently represent an integer of 1 or more, and m+n is 20 or more.) The polymerizable compound (A1) contains a compound represented by the following formula (a1-2): 【Chemistry 2】 (In the formula, R 11 represents a hydrogen atom or a methyl group, X 12 represents an alkylene group having 2 or 3 carbon atoms, and p represents an integer of 1 or more.) The active energy ray-curable resin composition, wherein the proportion of the polymerizable compound (A2) in the active energy ray-polymerizable compound (A) is 0.1 to 30 mass %, and the proportion of the polymerizable compound (A1) in the active energy ray-polymerizable compound (A) is 30 to 95 mass %.

2. The active energy ray-curable resin composition according to claim 1, comprising, as the polymerizable compound (A2), a compound represented by the following formula (a2-1): 【Chemistry 3】 (In the formula, R ２１ is a hydrogen atom or a methyl group, and Q ２１ is a single bond or a divalent linking group, R ２２ is an alkyl group having 14 to 22 carbon atoms.

3. 3. A cured product of the active energy ray-curable resin composition according to claim 1, wherein the cured product has a refractive index of 1.54 or more.

4. An optical sheet comprising a layer made of the cured product according to claim 3.

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