JP2023013069A - Active energy ray-curable resin composition, cured product and optical sheet - Google Patents

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 The present invention relates to an active energy ray-curable resin composition used for optical articles, a cured product obtained by curing the composition, and an optical sheet comprising the cured product.

2. Description of the Related Art In recent years, with the rapid development of display technology such as liquid crystal display devices, there is an increasing demand for new functions and high quality for sheet-like or film-like optical members used in these devices. An example of such an optical member is a prism sheet used as a light-condensing film for backlight.
The prism sheet has the effect of improving the luminance in front of the display by refracting the backlight light with the fine uneven structure on the surface. In recent years, prism sheets are required to have a high refractive index for further improvement of display brightness, and to have excellent abrasion resistance and self-healing properties.

For example, Patent Document 1 discloses an active energy ray-curable resin composition for optical articles containing fluorene-based (meth)acrylate and phenoxybenzyl acrylate, and a cured product obtained by curing the composition has a high refractive index. It is disclosed that it has excellent scratch resistance and suitable self-healing properties while having
Further, in Patent Document 2, a reaction product of a bisphenol A type epoxy resin and acrylic acid, a phenylphenoxyalkyl (meth)acrylate or the like, a specific mono- or difunctional linear (meth)acrylate compound, and a photo A resin composition for optical materials containing a polymerization initiator is disclosed, and is disclosed to be excellent in refractive index, hardness, resilience and the like.

WO2018/070256 JP 2012-219205 A

Recently, in addition to the above-mentioned high refractive index, abrasion resistance (scratch resistance), and self-healing, in order to improve durability for use in various environments, hydrophobic There is a growing demand for the addition of sexual functions. With conventional prism sheets that do not exhibit hydrophobicity, water easily adheres to the surface of the prism sheet due to temperature changes during transportation and terminal use. There is a possibility that the functionality of the seat may deteriorate.

An object of the present invention is to provide an optical sheet and a cured product that have a high refractive index, high wear resistance, and high self-healing properties, and exhibit a water contact angle to suppress the adhesion of moisture, and a cured product that can be used therefor. An object of the present invention is to provide an active energy ray-curable resin composition.

That is, the present invention provides the following inventions.
(1) An active energy ray-curable resin composition containing a polymerizable compound (A), a photopolymerization initiator (B) and a leveling agent (C), wherein the polymerizable compound (A) comprises an alkylene oxide chain A polymerizable compound (A1) having a structure and a polymerizable compound (A2) having an SP value of 8.88 or less, wherein the polymerizable compound (A1) is an alkylene oxide chain in the compound structure is contained so as to be 0.6 mmol/g or more in the total amount of the active energy ray-curable resin composition.
(2) The active energy ray-curable resin composition of (1), which contains a compound represented by the following formula (a2-1) as the polymerizable compound (A2).

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

(wherein 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 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), containing a compound represented by the following formula (a1-2) as the polymerizable compound (A1).

(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.)
(5) Active energy ray curing 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% by mass. mold resin composition.
(6) The active energy ray-curable resin 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% by mass. Composition.
(7) A cured product which is a cured product of the active energy ray-curable resin composition according to any one of (1) to (6) and has a refractive index of 1.54 or more.
(8) An optical sheet having a layer comprising the cured product of (7).

A cured product obtained by curing the active energy ray-curable resin composition of the present invention and an optical sheet are composed of a polymerizable compound having a certain amount or more of an alkylene oxide chain in its structure and a hydrophobic compound having a SP value of a certain value or less. By using a polymerizable compound, a photopolymerization initiator, and a leveling agent in combination, it is possible not only to satisfy the conventionally required properties of a high refractive index, high abrasion resistance and suitable self-healing properties, but also to achieve excellent self-healing properties. It develops a water contact angle. Therefore, the active energy ray-curable resin composition of the present invention can be used for various optical articles, such as prism sheets used in displays such as liquid crystal displays, lenticular lens sheets used in stereoscopic photography and projection screens, overhead It can be suitably applied to various optical sheets such as Fresnel lens sheets used for condenser lenses of projectors and the like, and diffraction gratings used for color filters and the like.

<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). .

[Polymerizable compound (A)]
The polymerizable compound (A) (hereinafter sometimes referred to as "(A) component" or "compound (A)") is a polymerizable compound (A1) having an alkylene oxide chain in its structure and an SP value of 8 and a polymerizable compound (A2) having a molecular weight of 0.88 or less.

(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 the compound (A1) has a certain amount or more of alkylene oxide chains, the abrasion resistance and self-healing properties of the cured composition are improved.
The alkylene oxide chain is not particularly limited as long as it has a "-O-(CH ₂ ) _p - structure" (p is an integer of 1 to 10, preferably an integer of 2 to 5), and ethylene An oxide chain, a propylene oxide chain, a butylene oxide chain, or a combination thereof is preferred, an ethylene oxide chain, a propylene oxide chain, or a combination thereof is more preferred, and an ethylene oxide chain is particularly preferred.

The component (A1) is a polymerizable compound and has in its structure a polymerizable group capable of being polymerized by an active energy ray. Polymerizable groups include (meth)acryloyl groups, (meth)acrylamide groups, vinyl groups, vinyl ether groups, vinyl ester groups, maleimide groups, epoxy groups and the like. As used herein, "(meth)acryloyl group" and "(meth)acrylamide group" are generic terms including acryloyl group and methacryloyl group, acrylamide group and methacrylamide group, respectively. Moreover, "(meth)acrylate" is a generic term including acrylate and methacrylate respectively.
Among them, as the polymerizable group, a (meth)acryloyl group is particularly preferable because of its high reactivity when irradiated with active energy rays.

Examples of component (A1) include ethylene oxide-modified poly(meth)acrylate of trimethylolpropane, propylene oxide-modified poly(meth)acrylate of trimethylolpropane, ethylene oxide-modified poly(meth)acrylate of ditrimethylolpropane, and ditrimethylol. Propane oxide-modified poly(meth)acrylate, pentaerythritol ethylene oxide-modified poly(meth)acrylate, pentaerythritol propylene oxide-modified poly(meth)acrylate, dipentaerythritol ethylene oxide-modified poly(meth)acrylate, tetramethylol alkylene oxide group-modified poly(meth)acrylate obtained by reacting (meth)acrylic acid with a polyol having an alkylene oxide group, such as ethylene oxide-modified poly(meth)acrylate of methane; ethylene oxide group-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, propylene oxide group-modified polyester poly(meth)acrylate Alkylene oxide-modified poly(meth)acrylate oligomer such as (meth)acrylate; di(meth)acrylate of ethylene oxide adduct of bisphenol A, di(meth)acrylate of propylene oxide adduct of bisphenol A, ethylene oxide of bisphenol F (Meth)acrylates of alkylene oxide adducts of bisphenol such as di(meth)acrylates of adducts and di(meth)acrylates of propylene oxide adducts of bisphenol F can be mentioned.

Preferred compounds for component (A1) include compounds represented by the following formula (a1-1).

In the formula, R ₁ and R ₂ each independently represent a hydrogen atom or a methyl group, and at least one is preferably a hydrogen atom. R ₁ and R ₂ may be the same group or different groups.
X ₁ and X ₂ each independently represent an alkylene group having 2 or 3 carbon atoms. When the number of carbon atoms is 2, the part becomes an ethylene oxide chain, and when the number of carbon atoms is 3, the part becomes a propylene oxide chain. X 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 setting m+n to 20 or more, excellent wear resistance and self-healing properties can be achieved. m+n is preferably 20-30, more preferably 20-25.
When m or n is 2 or more, the plurality of X ₁ or X ₂ may be the same or different, but from the viewpoint of ease of synthesis, the plurality of X ₁ or X ₂ may be the same and particularly preferably all X ₁ or X ₂ are the same.

A compound represented by the following formula (a1-2) is also preferable as the component (A1).

In the formula, R ₁₁ represents a hydrogen atom or a methyl group, preferably a hydrogen atom.
X ₁₂ represents an alkylene group having 2 or 3 carbon atoms, 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, more preferably 1 or 2,
When p is 2 or more, the plurality of X ₁₂ may be the same or different, but the plurality of X ₁₂ are preferably the same.
Since the compound represented by formula (a1-2) has a biphenyl structure, it contributes to increasing the refractive index of a cured product obtained by curing the composition.

In the composition of the present invention, component (A1) is contained in such a content that the content of alkylene oxide chains 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, even more preferably 0.6 to 1.0 mmol/g. By setting it to 0.6 mmol/g or more, good self-healing properties can be obtained, and by setting it to the above upper limit or less, it is possible to develop a water contact angle.

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

(Polymerizable compound (A2))
The polymerizable compound (A2) (hereinafter sometimes referred to as "component (A2)" or "compound (A2)") does not correspond to the component (A1) and has a polymerizable compound with an SP value of 8.88 or less. is a compound. By using the 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 indicating the affinity between raw materials, and was calculated by the Fedors method as an index for expressing hydrophobicity in the present invention.

The component (A2) is a polymerizable compound and has in its structure a polymerizable group capable of being polymerized by an active energy ray. As the polymerizable group, the same groups as described for the component (A1) can be used, and the component (A2) is preferably a (meth)acrylate having a (meth)acryloyl group.

As the component (A2) when it is a (meth)acrylate, a compound represented by the following formula (a2-1) is preferable.

In the formula, R ₂₁ is a hydrogen atom or a methyl group, preferably a hydrogen atom.
_Q21 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 these A divalent linking group formed by combining —O—, —S—, —CO—, and —CO ₂ — is exemplified. Since R ₂₂ is an alkyl group, Q ₂₁ is preferably not an unsubstituted alkylene group.
Among them, _Q21 is preferably a single bond.

R ₂₂ is an alkyl group having 14 to 22 carbon atoms. By using a hydrophobic compound having such a relatively long-chain alkyl group for R ₂₂ , the compound represented by formula (a2-1) has an SP value of component (A2) of 8.88 or less. , it becomes possible to impart a water contact angle to the composition of the present invention.
The number of carbon atoms in R ₂₂ is preferably 16-20, more preferably 18-20, and particularly preferably 16.
The alkyl group for R ₂₂ may be a chain alkyl group or a branched alkyl group. It is preferable because it can be obtained. In the case of a branched chain, the number of carbon atoms in the main chain is preferably 14 or more.

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

(Other polymerizable compounds)
The (A) component may contain polymerizable compounds other than the (A1) component and the (A2) component. Other polymerizable compounds include monofunctional compounds having one polymerizable group, and polyfunctional compounds having two or more polymerizable groups, which do not fall under the above components (A1) to (A2). can be used as appropriate.

Examples of monofunctional compounds 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, 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, dicyclopentenyloxyethyl (meth)acrylate, and other monofunctional (meth)acrylates can be preferably used. These monofunctional (meth)acrylates may be used singly or in combination.

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

As a monofunctional compound, phenylbenzyl acrylate represented by the following formula (4) is preferable because it tends to improve the refractive index of the obtained cured product while suitably maintaining the viscosity of the composition.

When using the compound represented by formula (4), 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 The content of the compound to be used is preferably 5 to 30% by mass, more preferably 10 to 20% by mass.

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, di Propylene 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, glycerol di(meth)acrylate, neopentyl glycol hydroxy Pivalic acid ester di(meth)acrylate, caprolactone-modified neopentylglycol hydroxypivalate di(meth)acrylate, tetrabromobisphenol A di(meth)acrylate, hydropivalaldehyde-modified trimethylolpropane di(meth)acrylate, 1,4- Cyclohexane dimethanol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, glycerol tri(meth)acrylate, alkyl-modified dipentaerythritol tri(meth)acrylate, ditrimethylolpropane tetra Polyfunctional (meth)acrylates such as (meth)acrylates can be exemplified.
As polyfunctional (meth)acrylates, polyfunctional oligomers having acryloyl groups such as urethane (meth)acrylates, polyester (meth)acrylates, and epoxy (meth)acrylates can also be used.
These monofunctional compounds and polyfunctional compounds may be used singly or in combination of two or more.

[Photoinitiator (B)]
The photopolymerization initiator (B) (hereinafter sometimes referred to as "(B) component") is not particularly limited, and various known and commonly used initiators can be used. In the production of articles using the composition of the present invention, active energy rays such as ultraviolet rays are often irradiated through the surface of a transparent base material that serves as a support. For this reason, component (B) is preferably an initiator that absorbs light in the long-wavelength region, for example, a photopolymerization initiator that exhibits photoinitiation in the range of 360 to 450 nm of ultraviolet rays.

Examples of component (B) include benzophenone, 3,3′-dimethyl-4-methoxybenzophenone, 4,4′-bisdimethylaminobenzophenone, 4,4′-bisdiethylaminobenzophenone, 4,4′-dichlorobenzophenone, and Michler’s ketone. , 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 benzyl 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-hydroxycyclohexylphenyl 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, benzyldimethylketal, benzyl-β-methoxyethylacetal, o-benzoylbenzoic acid methyl, bis(4-dimethylaminophenyl)ketone, p-dimethylaminoacetophenone, α,α-dichloro-4-phenoxyacetophenone, pentyl-4-dimethylaminobenzoate, 2-(o-chlorophenyl)-4,5-diphenyl imidazolyl 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, etc. be done.

(B) component may be used individually by 1 type, and may be used in combination of 2 or more type.

The amount of component (B) to be used is not particularly limited, but since it is easy to obtain suitable curability and suitable wear resistance and self-healing properties of the resulting cured product, is preferably 0.05 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, even more preferably 0.5 to 5 parts by mass.

[Leveling agent (C)]
The leveling agent (surface conditioner, hereinafter sometimes referred to as "component (C)") adjusts the state of the coating film surface layer formed by the composition of the present invention, and contains a leveling agent. It is possible to improve the wear resistance after curing. On the other hand, since the leveling agent reduces the surface tension of the coating film and enhances the wettability of the coating film, the use of the leveling agent results in a state in which the water contact angle is not developed. In the present invention, this problem is solved by using the component (A2) in combination, so that the water contact angle can be expressed even when the component (C) is used, and at the same time, good wear resistance and self- Curability can be achieved.

Component (C) includes, for example, acrylic leveling agents, silicone leveling agents, fluorine leveling agents, vinyl leveling agents, and the like. These leveling agents may be used singly or in combination of two or more.

Among these surface conditioning agents, silicon-based leveling agents are preferred from the viewpoint of improving self-healing properties. Examples of the silicon-based leveling agent include the BYK series manufactured by BYK-Chemie Japan.

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

The active energy ray-curable resin composition of the present invention may optionally contain other components as additives in addition to the above components (A) to (C). Additives are not particularly limited as long as they do not correspond to components (A) to (C), but photosensitizers, ultraviolet absorbers, antioxidants, silicon additives, and fluorine additives. , rheology control agents, defoamers, release agents, silane coupling agents, antistatic agents, antifogging agents, coloring agents, inorganic fillers, and the like.

The active energy ray-curable resin composition for optical articles of the present invention may contain a solvent if necessary. It is preferable because a resin composition can be obtained. Specifically, the solvent content in the active energy ray-curable resin composition for optical articles of the present invention is preferably 1% by mass or less, and preferably not substantially contained.

Examples of photosensitizers include amines, ureas, sulfur-containing compounds, phosphorus-containing compounds, chlorine-containing compounds, nitriles, and other nitrogen-containing compounds.

UV absorbers include, for example, 2-[4-{(2-hydroxy-3-dodecyloxypropyl)oxy}-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1, 3,5-triazine, 2-[4-{(2-hydroxy-3-tridecyloxypropyl)oxy}-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3 ,5-triazine and other triazine derivatives, 2-(2′-xanthenecarboxy-5′-methylphenyl)benzotriazole, 2-(2′-o-nitrobenzyloxy-5′-methylphenyl)benzotriazole, 2- xanthenecarboxy-4-dodecyloxybenzophenone, 2-o-nitrobenzyloxy-4-dodecyloxybenzophenone and the like.

Examples of antioxidants include hindered phenol antioxidants, hindered amine antioxidants, organic sulfur antioxidants, phosphate ester antioxidants, and the like.

Silicon additives include, for example, dimethylpolysiloxane, methylphenylpolysiloxane, cyclic dimethylpolysiloxane, methylhydrogenpolysiloxane, polyether-modified dimethylpolysiloxane copolymer, polyester-modified dimethylpolysiloxane copolymer, fluorine-modified dimethyl Polyorganosiloxanes having alkyl groups or phenyl groups such as polysiloxane copolymers and amino-modified dimethylpolysiloxane copolymers can be mentioned.

The inorganic filler (inorganic nanoparticles) preferably has a high refractive index and includes alumina, zirconia, titania, compounds thereof, or mixed oxides thereof, or metal oxides thereof. 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. A practical blending amount is in the range of 20 to 60% by mass of the inorganic nanoparticles with respect to the total amount of the component (A) and the inorganic nanoparticles. Among them, 30 to 50% by mass is more preferable in order to achieve both a higher refractive index and self-healing properties.

The amount of the various additives used is not particularly limited as long as it sufficiently exhibits its effect and does not hinder the curing by the active energy ray. It is preferably from 05 to 20 parts by mass, particularly preferably from 0.1 to 10 parts by mass.

The composition of the present invention may contain a solvent if necessary, but from the viewpoint of working environment contamination, the solvent content is preferably as low as possible. Specifically, the solvent content in the composition is preferably 1% by mass or less.

The active energy ray-curable resin composition of the present invention preferably has a viscosity of 50 to 5000 mPa·s at 25° C. because it can be easily applied and molded into a desired shape and thickness for use in various optical articles. , 100 to 2000 mPa·s. In particular, when it is applied to a prism sheet, it is easy to apply uniformly to the matrix of the prism sheet, and it is easy to duplicate the matrix having a fine uneven structure (the line speed can be increased). It is preferably 50 to 800 mPa·s.
Even if the viscosity is outside the above range, it can be used by adopting a method such as adjusting the viscosity by controlling the temperature of the composition.

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 the sample based on a prescribed method) was 5.0 mg KOH/ g or less is preferable because it becomes an active energy ray-curable resin composition for optical articles from which a cured product having excellent environmental stability is obtained, and 0 mgKOH/g to 3.0 mgKOH/g is particularly preferable.

<Cured product>
The active energy ray-curable resin composition of the present invention can be applied to a base material or molded, and then irradiated with an active energy ray to obtain a cured product depending on the intended use. Active energy rays include electron beams, ultraviolet rays, visible rays, and the like. When an electron beam is used as the active energy beam, an electron beam such as a Cockroft-Walton type accelerator, a Van de Graaff type electron accelerator, a resonance transformer type accelerator, an insulating core transformer type, a dynamitron type, a linear filament type or a high frequency type. The curable resin composition of the present invention can be cured using a generator. In addition, when using ultraviolet rays as active energy rays, irradiate and cure with mercury lamps such as ultra-high pressure mercury lamps, high pressure mercury lamps, low pressure mercury lamps, xenon lamps, carbon arcs, metal high lamps, high output LED-UV lamps, etc. can be done.

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, still more preferably 1.55 or more, and 1.56 or more. Especially preferred. Since the cured product has a high refractive index and suitable scratch resistance and the like, it can be suitably applied to various optical articles.

The hardness of the cured product of the present invention may be appropriately designed according to various uses. It is more preferably 100 MPa. By setting the elastic modulus within this range, the mechanical strength and toughness (elongation) are well balanced, and the restoring force necessary for self-healing can be easily exhibited.
The elastic modulus was measured using "RSAII" manufactured by Rheometric Scientific as a viscoelasticity measuring device, and the dynamic viscoelasticity was measured under the conditions of a temperature increase rate of 3°C/Min and a frequency of 3.5Hz. The value obtained by

The cured product of the present invention preferably has a glass transition temperature Tg of 40° C. or lower, more preferably 30° C. or lower, and particularly preferably 25° C. or lower. By setting it as the said glass transition temperature, it becomes easy to combine a high refractive index and favorable self-healing property. Although the lower limit of Tg is not particularly limited, it is preferably 5°C or higher, more preferably 10°C or higher, and particularly preferably 15°C or higher.
In addition, in the present invention, the use of components (A) to (C) and blending within a suitable range makes it easier to adjust the Tg within the range.
The glass transition temperature is a value obtained by reading the temperature at the peak position of tan δ represented by the ratio of the storage elastic modulus E′ and the complex elastic modulus E″ obtained by viscoelasticity measurement as Tg.

[Optical sheet]
The optical sheet of the present invention is an optical sheet having a layer comprising a cured product of the active energy ray-curable resin composition. The optical sheet is an optical sheet in which prisms and lenses made of the cured product are laminated on a transparent resin film. Examples include lenticular lens sheets used for projection screens, Fresnel lens sheets used for condenser lenses of overhead projectors, and optical sheets such as diffraction gratings used for color filters.

As a method for producing these optical sheets, the active energy ray-curable resin composition is filled on a matrix having a fine shape required according to various uses, and then air is poured onto the filled resin composition. The base material is laminated under pressure so as not to be mixed in, and the resin composition is cured by irradiating the base material with an active energy ray such as ultraviolet rays, and then released from the mother mold. be done. Alternatively, for example, after continuously filling the resin composition into a roll-shaped mother mold, the substrate is continuously brought into close contact with the filled resin composition so that air is not mixed in, and the UV light is irradiated from the substrate side. After curing the resin composition by irradiating it with an active energy ray, such as a continuous production method, the mold is released from the roll-shaped mother mold.

As the base material used for forming the optical sheet, a film-like, sheet-like or plate-like transparent base material can be used. The material of the base material 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, methyl methacrylate copolymers, and the like. acrylic resins, styrene resins, polysulfone resins, polyethersulfone resins, polycarbonate resins, vinyl chloride resins, polymethacrylimide resins, and the like. Inorganic substrates such as glass substrates can also be used in the same manner.

Among various optical sheets, the active energy ray-curable resin composition of the present invention can be suitably applied to prism sheets used in various displays. The prism sheet has a plurality of fine prism-shaped parts on one side of the sheet-like molded body, and is usually arranged on the back surface (light source side) of the liquid crystal display element so that the prism surface faces the element side. be done.

The prism sheet is a sheet having a prism layer composed 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 70 to 110°. The angle is preferably 75° to 100°, particularly preferably 80° to 95°, from the standpoint of excellent light-condensing properties and improved brightness.

The pitch of the prisms is preferably 100 μm or less, and particularly preferably 70 μm or less, from the viewpoint of preventing moire patterns on the screen and improving the definition of the screen. The height of the irregularities of the prism is determined by the value of the apical angle θ of the prism and the pitch of the prism, and is preferably 50 μm or less. Further, the sheet thickness of the prism lens is preferably thicker from the standpoint of strength, but is preferably thinner optically in order to suppress light absorption.

EXAMPLES The present invention will be described more specifically with reference to examples and comparative examples below. All parts and percentages in the examples are based on mass unless otherwise specified. Measurements and evaluations of properties, etc. in Examples and Comparative Examples were carried out as follows.

<Refractive index>
The refractive indices of the resin compositions prepared in Examples and Comparative Examples were measured at a reference wavelength (589 nm) using a multi-wavelength Abbe refractometer (DR-M2) manufactured by ATAGO. The numbers in the table indicated the refractive index of the formulated composition.

<Viscosity>
The viscosities at 25° C. of the resin compositions prepared in Examples and Comparative Examples were measured using an E-type viscometer (TV-25, type H type) manufactured by Toki Sangyo.

<Self-healing>
A prism matrix having a prism pitch interval of 50 μm, a prism height of 25 μm, and an apex angle of 90° was filled with the resin composition prepared in Examples and Comparative Examples, and a PET film of 125 μm was layered thereon while applying pressure with a roller. After bonding, the resin composition was cured from the PET film side with a high-pressure mercury lamp with an irradiation amount of an integrated light amount of 400 mJ/cm 2 to prepare a prism sheet. The obtained prism sheet was scratched with an awl for about 3 cm, and the time until the scratch (line streak) formed at that time disappeared was visually observed and evaluated according to the following criteria.
5: Instantly restored (scratches disappeared)
4: Restored within 10 seconds (scratches disappeared)
3: Restored within 1 minute (scratches disappeared)
2: Restored within 5 minutes (scratches disappeared)
1: Restored in 15 minutes or more (scratches disappeared)
0: Do not restore

<Abrasion resistance>
A circular diffusion film with a diameter of 1 cm was placed on a prism sheet obtained in the same manner as described above, and a load of 400 g was applied to the prism sheet. was rubbed 40 times back and forth over a distance of 10 cm, and the belt-like scratches on the surface were evaluated by the area of the scratched portion. The evaluation was carried out in a room at 23° C., and judged according to the following criteria.
A: The area of the damaged portion is 5 cm ² or less B: The area of the damaged portion is greater than 5 cm ² and 7 cm ² or less C: The area of the damaged portion is greater than 7 cm ²

<Water contact angle>
50 μl of deionized water was protruded from a syringe onto the prism sheet obtained in the same manner as above, and the water contact angle was measured using a water contact angle meter (DMo-501 model) manufactured by Kyowa Interface Science. . The evaluation was carried out in a room at 23° C., observed from a direction parallel to the ridgeline of the prism sheet, and the measurement results were evaluated as follows. A grade of B or above is acceptable.
A: Water contact angle of 50° or more after 1 second of droplet deposition, and water contact angle retention rate of 80% or more after 5 minutes B: Water contact angle of 50° or more after 1 second of droplet deposition, and 5 minutes after Water contact angle retention rate of less than 80% C: Water contact angle 30 ° or more and less than 50 ° after 1 second of droplet deposition, and water contact angle retention rate of 80% or more after 5 minutes D: 1 second after droplet deposition The water contact angle of 30 ° or more and less than 50 °, and the water contact angle retention rate after 5 minutes is less than 80% E: The water contact angle after 1 second of droplet deposition is less than 30 °

(Examples 1-4, Comparative Examples 1-5)
The compounds were melt-mixed according to the formulation shown in the table below to prepare a resin composition. The alkylene oxide content (mmol/g) of the polymerizable compound (A1) is described in the table as "alkylene oxide content".
The above evaluation was performed using the obtained resin composition. In addition, the numerical value of the composition compounding quantity in a table|surface is the mass %.

The compounds listed in the above table are as follows.
A1-1: Ethylene oxide-modified bisphenol A diacrylate ("MIRAMER M-2200" manufactured by MIWON, in the formula (a1-1), R ₁ and R ₂ are hydrogen atoms, X ₁ and X ₂ are ethylene groups, m + n = 20 compound, ethylene oxide modification amount 20 mol)
A1-2: Ethylene oxide-modified bisphenol A diacrylate ("MIRAMER M-2100" manufactured by MIWON, in the formula (a1-1), R ₁ and R ₂ are hydrogen atoms, X ₁ and X ₂ are ethylene groups, m + n = 10 compound, ethylene oxide modification amount 10 mol)
A1-3: Ethylene oxide-modified acrylate of o-phenylphenol (“MIRAMER M-1142” manufactured by MIWON, a compound in which R ₁₁ is a hydrogen atom, X ₁₂ is an ethylene group, p=1 in the formula (a1-2), Ethylene oxide modification amount 1 mol)
A2-1: Stearyl acrylate (SP value: 8.80) (“KOMERATE A189” manufactured by KPX, in the formula (a2-1), R ₂₁ is a hydrogen atom, Q ₂₁ is a single bond, and R ₂₂ is a carbon number of 18 straight-chain compounds)
A2-2: Cetyl acrylate (SP value: 8.83) ("KOMERATE A169" manufactured by KPX, in the formula (a2-1), R ₂₁ is a hydrogen atom, Q ₂₁ is a single bond, R ₂₂ is a C 16 straight-chain compounds)
A2-3: Dodecyl acrylate (SP value: 8.89) (“KOMERATE A129” manufactured by KPX, in the formula (a2-1), R ₂₁ is a hydrogen atom, Q ₂₁ is a single bond, and R ₂₂ is a carbon number of 12 straight-chain compounds)
A2-4: behenyl acrylate (SP value: 8.77) ("KOMERATE A229" manufactured by KPX), in the formula (a2-1), R ₂₁ is a hydrogen atom, Q ₂₁ is a single bond, and R ₂₂ has 22 carbon atoms straight-chain compounds)
A2-5: Stearyl methacrylate (SP value: 8.74) (“KOMERATE A189M” manufactured by KPX, in the formula (a2-1), R ₂₁ is a methyl group, Q ₂₁ is a single bond, and R ₂₂ is a carbon number of 18 straight-chain compounds)
A2-6: Isobornyl acrylate (SP value: 9.93) (“IBXA” manufactured by Osaka Organic Chemical Industry Co., Ltd., R ₂₁ in the above formula (a2-1) is a hydrogen atom R ₂₂ or a portion corresponding to Q ₂₁ is isobornyl group)
A2-7: Tricyclodecanedimethanol diacrylate (SP value: 11.30) (“KOMERATE D0013” manufactured by KPX, R ₂₁ corresponds to a hydrogen atom/R ₂₂ or Q ₂₁ in the formula (a2-1) A compound having a tricyclodecane skeleton having a monoacrylate in its portion)
A2-8: Cyclohexyl acrylate (SP value: 10.04) (“Viscoat #155” manufactured by Osaka Organic Chemical Industry Co., Ltd., R ₂₁ in the above formula (a2-1) is a hydrogen atom R ₂₂ or a portion corresponding to Q ₂₁ is a cyclohexyl group compound)
B1: 1-hydroxycyclohexyl phenyl ketone ("OMNIRAD184" manufactured by IGM RESINS B.V.)
C1: Polyether-modified polydimethylsiloxane ("BYK-333" manufactured by BYK-Chemie Japan)

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 expression of water contact angle, self-healing property, and wear resistance.
On the other hand, Comparative Example 1 having an alkylene oxide content of less than 0.6 mmol/g is inferior in self-healing property and abrasion resistance, and Comparative Examples 2 to 5, which do not contain a polymerizable compound having an SP value of 8.88 or less, It was confirmed that the contact angle with water was not developed and the adhesion of water could not be suppressed.

As described above, the active energy ray-curable resin composition of the present invention can be suitably used for various optical members such as prism sheets.

Claims (8)

An active energy ray-curable resin composition containing 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 or less,
The active energy ray-curable resin composition, wherein 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. thing. 2. The active energy ray-curable resin composition according to claim 1, containing a compound represented by the following formula (a2-1) as the polymerizable compound (A2).

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

(wherein 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 independently represent an integer of 1 or more, and m+n is 20 or more.) The active energy ray-curable resin composition according to any one of claims 1 to 3, comprising a compound represented by the following formula (a1-2) as the polymerizable compound (A1).

(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 type according to any one of claims 1 to 4, wherein the proportion of the polymerizable compound (A2) in the active energy ray polymerizable compound (A) is 0.1 to 30% by mass. Resin composition. The active energy ray-curable resin composition according to any one of claims 1 to 5, wherein the proportion of the polymerizable compound (A1) in the active energy ray polymerizable compound (A) is 30 to 95% by mass. thing. A cured product of the active energy ray-curable resin composition according to any one of claims 1 to 6, wherein the cured product has a refractive index of 1.54 or more. An optical sheet having a layer comprising the cured product according to claim 7 .