JP7626107B2 - Urethane (meth)acrylate resin, active energy ray curable composition, cured product, and laminated film - Google Patents

Description

The present invention relates to a urethane (meth)acrylate resin that exhibits excellent scratch resistance, flexibility, curl resistance, and impact resistance in a cured coating film, and to an active energy ray-curable composition, cured product, and laminate film that contain the same.

Plastic films manufactured using polyethylene terephthalate resin (PET), acrylic resin, polycarbonate resin, acetylated cellulose resin, etc. are widely used in industrial applications, such as protective films for polarizing plates incorporated inside flat panel displays and surface protective films for touch panels. These plastic films, when used alone, are prone to surface scratches, have low processability and are prone to cracking and chipping, and therefore lack sufficient performance. Therefore, they are usually used with a coating layer made of an active energy ray-curable resin, etc., provided on the surface to compensate for these performance issues.

As a coating agent for reinforcing plastic films, for example, a resin composition containing a urethane acrylate obtained by reacting dipentaerythritol polyacrylate having a hydroxyl value in the range of 80 to 120 mgKOH/g with hexamethylene diisocyanate is known (see, for example, Patent Document 1). Although the resin composition has high surface hardness and excellent scratch resistance in the cured product, it is prone to curling, and the toughness and flexibility of the coating film are insufficient, so that it is prone to cracking due to external impact.

Therefore, there was a demand for a material capable of forming a cured coating film that has excellent scratch resistance, curl resistance, flexibility, and impact resistance.

International Publication No. 2010/146801

The problem that the present invention aims to solve is to provide a urethane (meth)acrylate resin capable of forming a cured coating film that has high hardness and excellent scratch resistance, flexibility, and curl resistance, and an active energy ray-curable composition, cured product, and laminate film that contain the same.

As a result of intensive research into solving the above problems, the inventors discovered that the above problems could be solved by using a urethane (meth)acrylate resin whose essential reaction raw materials were at least two types of isocyanate compounds and dipentaerythritol (meth)acrylate having a specific hydroxyl value, and thus completed the present invention.

That is, the present invention relates to the following.
[1] A urethane (meth)acrylate resin comprising, as essential reaction raw materials, an isocyanate compound (A1) that does not contain a bond derived from an isocyanate group in the molecule, an isocyanate compound (A2) that contains a bond derived from an isocyanate group in the molecule, and dipentaerythritol (meth)acrylate (B), wherein the hydroxyl value of the dipentaerythritol (meth)acrylate (B) is in the range of more than 120 mg KOH/g and not more than 150 mg KOH/g.
[2] The urethane (meth)acrylate resin according to [1], wherein the NCO content of the isocyanate compound (A1) is in the range of 20 to 55%, and the NCO content of the isocyanate compound (A2) is in the range of 10 to 25%.
[3] The urethane (meth)acrylate resin according to [1] or [2], wherein the equivalent ratio [(A1)/(A2)] of the isocyanate compound (A2) to the isocyanate compound (A1) in the reaction raw materials is in the range of 70/30 to 95/5.
[4] The urethane (meth)acrylate resin according to any one of [1] to [3], further comprising a hydroxyl group-containing acrylic acid ester (C) other than the dipentaerythritol (meth)acrylate (B) as a reaction raw material.
[5] The urethane (meth)acrylate resin according to any one of [1] to [4], wherein the dipentaerythritol (meth)acrylate (B) contains dipentaerythritol hexa(meth)acrylate.
[6] The urethane (meth)acrylate resin according to any one of [1] to [5], wherein the content of the dipentaerythritol hexa(meth)acrylate in the dipentaerythritol (meth)acrylate (B) is in the range of 10 to 50 mass%.
[7] An active energy ray-curable composition comprising the urethane (meth)acrylate resin according to any one of [1] to [6] and a photopolymerization initiator.
[8] A cured product of the active energy ray-curable composition according to [7].
[9] A laminate film having a cured coating film made of the cured product described in [8] on one or both sides of a substrate.
[10] The laminate film according to [9], wherein the thickness of the substrate is in the range of 50 to 80 μm and the thickness of the cured coating film is in the range of 5 to 20 μm.

The urethane (meth)acrylate resin of the present invention can form a cured coating film that is highly hard and has excellent scratch resistance, curl resistance, and flexibility, and can therefore be suitably used as a protective coating agent for the surfaces of various substrates. Furthermore, a laminate film having the cured coating film has high hardness, but also has excellent scratch resistance and curl resistance, and is highly flexible and unlikely to crack when bent or rolled up.

In this specification, "(meth)acrylate" is a general term for methacrylate and acrylate, and "(meth)acryloyl group" similarly refers to a general term for methacryloyl group and acrylic group.
In this specification, the active energy ray-curable composition is also simply referred to as a composition.
Furthermore, in this specification, the term "NCO content" refers to the amount of isocyanate groups present in an isocyanate compound expressed as a mass fraction.
In the present invention, an isocyanate group may be described as "NCO."

[Urethane (meth)acrylate resin]
The urethane (meth)acrylate resin of the present invention contains, as essential reaction raw materials, an isocyanate compound (A1) that does not contain a bond derived from an isocyanate group in the molecule, an isocyanate compound (A2) that contains a bond derived from an isocyanate group in the molecule, and dipentaerythritol (meth)acrylate (B).

[Isocyanate compound (A1)]
The isocyanate compound (A1) is a compound that does not contain a bond derived from an isocyanate group in the molecule, but contains one or more isocyanate groups in one molecule. The bond derived from an isocyanate group in the present invention refers to an amide bond (-NHCO-), a urethane bond (-NHCOO-), a urea bond (-NHCONH-), a biuret bond, an allophanate bond, an isocyanurate bond, a uretdione bond, etc., which are formed by the reaction of an isocyanate group with various nucleophiles.

The NCO content of the isocyanate compound (A1) is preferably in the range of 10 to 70%, more preferably in the range of 15 to 60%, and particularly preferably in the range of 20 to 55%. By setting it in these ranges, a urethane (meth)acrylate resin can be obtained that can form a cured coating film that has high hardness and excellent scratch resistance, curl resistance, and flexibility.

Examples of the isocyanate compound (A1) include aliphatic isocyanate compounds and isocyanate compounds having an aromatic ring or alicyclic structure in the molecule.

Examples of the aliphatic isocyanate compound include aliphatic diisocyanate compounds such as butane diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate. These aliphatic isocyanate compounds can be used alone or in combination of two or more.

The isocyanate compounds having an aromatic ring or alicyclic structure in the molecule include alicyclic diisocyanate compounds such as isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, and 1,3-bis(isocyanatomethyl)cyclohexane; aromatic diisocyanate compounds such as diphenylmethane diisocyanate and 1,5-naphthalene diisocyanate;

Examples include polymethylene polyphenyl polyisocyanate having a repeating structure represented by the following structural formula (1). These isocyanate compounds having an aromatic ring or alicyclic structure in the molecule can be used alone or in combination of two or more kinds.

（式中、Ｒ_１はそれぞれ独立に水素原子、炭素原子数１～６の炭化水素基の何れかである。Ｒ_２はそれぞれ独立に炭素原子数１～４のアルキル基、又は構造式（１）で表される構造部位と＊印が付されたメチレン基を介して連結する結合点の何れかである。ｍは０又は１～３の整数であり、ｌは１以上の整数である。）

(In the formula, _R1 is independently either a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. _R2 is independently either an alkyl group having 1 to 4 carbon atoms, or a bonding point connecting the structural portion represented by structural formula (1) via a methylene group marked with an *. m is 0 or an integer of 1 to 3, and l is an integer of 1 or more.)

[Isocyanate compound (A2)]
The isocyanate compound (A2) is a compound that contains a bond derived from an isocyanate group in the molecule and contains one or more isocyanate groups in one molecule.

The NCO content of the isocyanate compound (A2) is preferably in the range of 10 to 25%, more preferably in the range of 12 to 20%, and particularly preferably in the range of 15 to 18%. By setting it in these ranges, a urethane (meth)acrylate resin can be obtained that can form a cured coating film that has high hardness and excellent scratch resistance, curl resistance, and flexibility.

As the isocyanate compound (A2), for example, modified products of various isocyanate compounds, such as isocyanurate modified products, biuret modified products, and allophanate modified products, can be used.
Examples of the various isocyanate compounds include aliphatic diisocyanate compounds such as butane diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate, alicyclic diisocyanate compounds such as isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, and 1,3-bis(isocyanatomethyl)cyclohexane, and aromatic diisocyanate compounds such as diphenylmethane diisocyanate and 1,5-naphthalene diisocyanate. These isocyanate compounds (A2) can be used alone or in combination of two or more.

The isocyanate compound (A2) may be a compound obtained by reacting various isocyanate compounds with polyols. In this case, the method for synthesizing the isocyanate compound (A2) is not particularly limited, and various known methods can be used, for example, a method of reacting a polyol (i) with an isocyanate compound (ii) under conditions of an excess of isocyanate groups.
Examples of the polyol (i) include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, butylene glycol, 1,6-hexanediol, 3-methyl-1,5-pentane glycol, neopentyl glycol, polytetramethylene glycol, hexanetriol, trimellitolpropane, an ethylene oxide or propylene oxide adduct of bisphenol A, hydrogenated bisphenol A, glycerin, pentaerythritol, and the like, as well as condensation polymers of the above-mentioned polyols with polybasic acids or polybasic acid anhydrides. One or more of these may be used.
Examples of polybasic acids and polybasic acid anhydrides include aromatic polybasic acids such as phthalic acid and phthalic anhydride, and aliphatic polybasic acids such as adipic acid and sebacic acid.
As the isocyanate compound (ii), the compounds exemplified as the isocyanate compound (A1) can be used. The isocyanate compound (ii) may be used alone or in combination of two or more.

[Equivalent ratio of isocyanate compound (A2) to isocyanate compound (A1)]
The equivalent ratio [(A1)/(A2)] of the isocyanate compound (A2) to the isocyanate compound (A1) in the reaction raw materials is preferably in the range of 40/60 to 99/1, more preferably in the range of 50/50 to 97/3, and particularly preferably in the range of 70/30 to 95/5. By adjusting the equivalent ratio to within these ranges, a urethane (meth)acrylate resin capable of forming a cured coating film having high hardness and excellent scratch resistance, curl resistance, and flexibility can be obtained.

In this specification, the term "equivalent ratio" refers to the ratio of the amount of substance of isocyanate groups derived from the isocyanate compound (A2) to the amount of substance of isocyanate groups derived from the isocyanate compound (A1) used as a raw material for the urethane (meth)acrylate resin of the present invention.
The amount of substance of the isocyanate group derived from the isocyanate compound (A1) is calculated by multiplying the mass of the isocyanate compound (A1) used by its NCO content to calculate the mass of NCO derived from the isocyanate compound (A1) used, and then dividing the mass of NCO by 42 (the molecular weight of NCO). The same applies to the isocyanate compound (A2).
More specifically, for example, when 10 g of an isocyanate compound (A1) having an NCO content of 42% is used as a raw material for a urethane (meth)acrylate resin, the mass of NCO derived from the isocyanate compound (A1) is 4.2 g (0.1 mol), and therefore the amount of substance of the isocyanate group derived from the isocyanate compound (A1) is 0.1 mol.

[Dipentaerythritol (meth)acrylate (B)]
The dipentaerythritol (meth)acrylate (B) is a compound in which a part of the hydroxyl groups of dipentaerythritol is (meth)acrylated, and may be a single compound or a mixture of multiple compounds as long as it has a hydroxyl group capable of reacting with the isocyanate compound (A1) and the isocyanate compound (A2). In other words, in the former case, dipentaerythritol mono(meth)acrylate, dipentaerythritol di(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, and dipentaerythritol penta(meth)acrylate can each be used alone as the dipentaerythritol (meth)acrylate (B). In the latter case, a mixture containing one or more of dipentaerythritol mono(meth)acrylate, dipentaerythritol di(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, and dipentaerythritol penta(meth)acrylate can be used, and further, dipentaerythritol hexa(meth)acrylate can be contained, if necessary.

The dipentaerythritol (meth)acrylate (B) preferably contains dipentaerythritol hexa(meth)acrylate as an essential component, since it is possible to obtain a urethane (meth)acrylate resin capable of forming a cured coating film having high hardness and excellent scratch resistance, flexibility, and curl resistance. In addition to dipentaerythritol hexa(meth)acrylate, the dipentaerythritol (meth)acrylate may contain dipentaerythritol penta(meth)acrylate, dipentaerythritol tetra(meth)acrylate, and dipentaerythritol tri(meth)acrylate in any ratio.

When the dipentaerythritol (meth)acrylate (B) contains the dipentaerythritol hexa(meth)acrylate, the content of the dipentaerythritol hexa(meth)acrylate in the dipentaerythritol (meth)acrylate (B) is preferably in the range of 10 to 50% by mass, more preferably in the range of 15 to 45% by mass, and particularly preferably in the range of 20 to 40% by mass, since a urethane (meth)acrylate resin capable of forming a cured coating film having excellent scratch resistance, flexibility, curl resistance, and impact resistance can be obtained.

In the present invention, the content of each component in the dipentaerythritol (meth)acrylate (B) and the ratio of the content of each component are values calculated from the area ratio of a liquid chromatography chart measured under the following conditions.
[Measurement conditions]
Apparatus: Shimadzu Corporation "LCMS-2010EV"
Data processing: Shimadzu Corporation "LCMS Solution"
Column: Tosoh Corporation "ODS-100V" (2.0 mm ID x 150 mm, 3 μm) 40° C.
Eluent: water/acetonitrile, 0.4 mL/min Detector: PDA, MS
Sample preparation: 1. Dissolve 50 mg of sample in 10 ml of acetonitrile (for LC)
2. Vortex for 30 seconds.
3. Leave to stand for 30 minutes
4. Calculation of area ratio after passing the liquid through a 0.2 μm filter and using it as a measurement sample: Calculated at a UV wavelength of 210 nm

The hydroxyl value of the dipentaerythritol (meth)acrylate (B) is more than 120 mgKOH/g and not more than 150 mgKOH/g, preferably in the range of 122 to 145 mgKOH/g, and more preferably in the range of 122 to 140 mgKOH/g, in order to obtain a urethane (meth)acrylate resin capable of forming a cured coating film having excellent scratch resistance, flexibility, curl resistance, and impact resistance.

The hydroxyl value of the dipentaerythritol (meth)acrylate (B) is an actual value measured in accordance with the neutralization titration method of JIS K 0070 (1992).

The dipentaerythritol (meth)acrylate (B) can be produced, for example, by esterifying dipentaerythritol with acrylic acid. When produced by this method, a high molecular weight component (b') such as an addition reaction product between dipentaerythritol (meth)acrylates (B) may be produced as a by-product. The high molecular weight component (b') may be purified and removed before use, or the dipentaerythritol (meth)acrylate (B) crude product containing the high molecular weight component (b') may be used as a raw material for the urethane (meth)acrylate resin. In this case, the content of the high molecular weight component (b') in the dipentaerythritol (meth)acrylate (B) crude product is preferably in the range of 1 to 20% by mass.

The urethane (meth)acrylate resin has the isocyanate compound (A1), the isocyanate compound (A2), and the dipentaerythritol (meth)acrylate (B) as essential reaction raw materials, and can further include other hydroxyl group-containing (meth)acrylic acid esters (C) as necessary.

[Hydroxyl group-containing (meth)acrylic acid ester (C)]
The hydroxyl group-containing (meth)acrylic ester (C) is a compound that contains one or more hydroxyl groups and (meth)acryloyl groups in one molecule and has a structure different from that of the dipentaerythritol (meth)acrylate (B).

Examples of the hydroxyl group-containing (meth)acrylic acid ester (C) include hydroxy(meth)acrylate compounds.
Examples of the hydroxy(meth)acrylate compound include aliphatic (meth)acrylate compounds such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, glycerin di(meth)acrylate, trimethylolpropane di(meth)acrylate, and pentaerythritol tri(meth)acrylate; aromatic ring-containing (meth)acrylate compounds such as 4-hydroxyphenyl acrylate, β-hydroxyphenethyl acrylate, 4-hydroxyphenethyl acrylate, 1-phenyl-2-hydroxyethyl acrylate, 3-hydroxy-4-acetylphenyl acrylate, and 2-hydroxy-3-phenoxypropyl acrylate; and mixtures of the (meth)acrylate compounds with ethylene oxide, propylene oxide, tetrahydrofuran, ethyl glycidyl ether, propyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, allyl glycidyl ether, and the like. polyether-modified (meth)acrylate compounds obtained by ring-opening polymerization of various cyclic ether compounds such as butyl ether; lactone-modified (meth)acrylate compounds obtained by polycondensation of the above-mentioned (meth)acrylate compounds with lactone compounds such as ε-caprolactone; and compounds obtained by reaction of various polyol compounds such as ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 3-methyl-1,3-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, glycerin, glycerin mono(meth)acrylate, trimethylolethane, trimethylolmethane mono(meth)acrylate, trimethylolpropane, trimethylolpropane mono(meth)acrylate, pentaerythritol mono(meth)acrylate, and pentaerythritol di(meth)acrylate with (meth)acrylic acid. These hydroxy (meth) acrylate compounds can be used alone or in combination of two or more. Among these, aliphatic (meth) acrylate compounds or their polyether modified products and lactone modified products are preferred because they can provide a urethane (meth) acrylate resin capable of forming a cured coating film having high hardness and excellent scratch resistance, flexibility, and curl resistance. In addition, when these hydroxy (meth) acrylate compounds are used as the hydroxyl group-containing compound (C), the ratio of the dipentaerythritol (meth) acrylate (B) to the total mass of the dipentaerythritol (meth) acrylate (B) and the hydroxy (meth) acrylate compound is preferably 70% by mass or more, more preferably 80% by mass or more, because the effects of the present invention are fully achieved.

[Method for producing urethane (meth)acrylate resin]
Examples of the method for producing the urethane (meth)acrylate resin include a method in which the isocyanate compound (A1), the isocyanate compound (A2), and the dipentaerythritol (meth)acrylate (B) are used in such a ratio that the molar ratio [(NCO)/(OH)] of the isocyanate groups in the isocyanate (A1) and the isocyanate compound (A2) to the hydroxyl groups in the dipentaerythritol (meth)acrylate (B) is in the range of 1/1.05 to 1/2, and the reaction is performed at a temperature in the range of 20 to 120° C. using a urethanization catalyst as necessary.

The (meth)acryloyl group equivalent of the urethane (meth)acrylate resin is preferably in the range of 100 to 500 g/eq, more preferably in the range of 100 to 250 g/eq, since a cured coating film excellent in high hardness, scratch resistance, flexibility, and curl resistance can be formed. Note that the (meth)acryloyl group equivalent of the urethane (meth)acrylate resin in the present invention is a theoretical value calculated from the reaction raw materials.

In addition, the weight average molecular weight (Mw) of the urethane (meth)acrylate resin is preferably in the range of 1,500 to 100,000, more preferably in the range of 3,000 to 50,000, since it is possible to form a cured coating film that has excellent hardness, scratch resistance, flexibility, and curl resistance.

The weight average molecular weight (Mw) of the urethane (meth)acrylate resin is a value measured by gel permeation chromatography (GPC).

[Active energy ray-curable composition]
The active energy ray-curable composition of the present invention contains the urethane (meth)acrylate resin and a photopolymerization initiator.

The photopolymerization initiator may be, for example, various 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; various 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; various 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-diphenylimidazolyl Examples of such photopolymerization initiators include 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-amyl anthraquinone, and β-chloroanthraquinone. These photopolymerization initiators can be used alone or in combination of two or more.

In addition, among the photopolymerization initiators, it is preferable to use one or a mixture of two or more selected from the group consisting of 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, thioxanthone and thioxanthone derivatives, 2,2'-dimethoxy-1,2-diphenylethane-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone, and 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, because these are active against light of a wider range of wavelengths and can improve the curability of the cured coating film of the active energy ray-curable composition.

Commercially available products of the photopolymerization initiator include, for example, "Omnirad-1173", "Omnirad-184", "Omnirad-127", "Omnirad-2959", "Omnirad-369", "Omnirad-379", "Omnirad-907", "Omnirad-4265", "Omnirad-1000", "Omnirad-651", "Omnirad-TPO", "Omnirad-819", "Omnirad-2022", "Omnirad-2100", "Omnirad-754", "Omnirad-784", "Omnirad-500", "Om Examples include "nirad-81" (manufactured by IGM), "Kayacure-DETX", "Kayacure-MBP", "Kayacure-DMBI", "Kayacure-EPA", "Kayacure-OA" (manufactured by Nippon Kayaku Co., Ltd.), "Bicure-10", "Bicure-55" (manufactured by Stouffer Chemical Co., Ltd.), "Trigonal P1" (manufactured by Akzo), "Sandray 1000" (manufactured by Sandoz Co., Ltd.), "Deep" (manufactured by Upjohn), "Quantacure-PDO", "Quantacure-ITX", "Quantacure-EPD" (manufactured by Ward Blenkinsop Co., Ltd.), and "Runtecure-1104" (manufactured by Runtec).

The amount of the photopolymerization initiator added is preferably an amount that can fully function as a photopolymerization initiator and does not cause crystal precipitation or deterioration of the coating film properties. Specifically, the amount is preferably in the range of 0.05 to 20 parts by weight, and more preferably in the range of 0.1 to 10 parts by weight, per 100 parts by weight of the urethane (meth)acrylate resin.

In addition, the active energy ray-curable composition may further contain a photosensitizer, since this can improve the curability of the cured coating film of the active energy ray-curable composition.

Examples of the photosensitizer include amine compounds such as aliphatic amines and aromatic amines, urea compounds such as o-tolylthiourea, and sulfur compounds such as sodium diethyldithiophosphate and s-benzylisothiuronium-p-toluenesulfonate.

The active energy ray curable composition of the present invention may further contain, in addition to the urethane (meth)acrylate resin, other photocurable compounds (R), organic solvents, ultraviolet absorbers, antioxidants, silicon-based additives, fluorine-based additives, silane coupling agents, phosphate ester compounds, organic beads, inorganic fine particles, inorganic fillers, rheology control agents, defoamers, antifogging agents, colorants, etc.

Examples of the other photocurable compounds (R) include various (meth)acrylate monomers, urethane (meth)acrylate resins other than the urethane (meth)acrylate resins, epoxy (meth)acrylate resins, dendrimer-type (meth)acrylate resins, and (meth)acryloyl group-containing acrylic resins.

The (meth)acrylate monomer is, for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, glycidyl (meth)acrylate, acryloylmorpholine, N-vinylpyrrolidone, tetrahydrofurfuryl acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isobornyl (meth)acrylate, isodecyl (meth)acrylate, Acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, cetyl (meth)acrylate, stearyl (meth)acrylate, benzyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, ethyl carbitol (meth)acrylate, phosphate (meth)acrylate, ethylene oxide modified phosphate (meth)acrylate, phenoxy (meth)acrylate, ethylene oxide modified phenoxy (meth)acrylate, propylene oxide modified phenoxy (meth)acrylate, nonyl phenoxy (meth)acrylate, ethylene oxide modified nonylphenol (meth)acrylate, propylene oxide modified nonylphenol (meth)acrylate, methoxydiethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, methoxypropylene glycol (meth)acrylate, 2-(meth)acryloyloxyethyl-2-hydroxypropyl phthalate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 2-(meth)acryloyloxyethyl hydrogen phthalate, 2-(meth)acryloyloxyethyl Mono(meth)acrylates such as 2-(meth)acryloyloxypropyl hydrogen phthalate, 2-(meth)acryloyloxypropyl hexahydrohydrogen phthalate, 2-(meth)acryloyloxypropyl tetrahydrohydrogen phthalate, dimethylaminoethyl (meth)acrylate, trifluoroethyl (meth)acrylate, tetrafluoropropyl (meth)acrylate, hexafluoropropyl (meth)acrylate, octafluoropropyl (meth)acrylate, octafluoropropyl (meth)acrylate, and adamantyl mono(meth)acrylate;

Di(meth)acrylates such as butanediol di(meth)acrylate, hexanediol di(meth)acrylate, ethoxylated hexanediol di(meth)acrylate, propoxylated hexanediol di(meth)acrylate, diethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, ethoxylated neopentyl glycol di(meth)acrylate, hydroxypivalic acid neopentyl glycol di(meth)acrylate, glycerin di(meth)acrylate, trimethylolpropane di(meth)acrylate, and pentaerythritol di(meth)acrylate;

Tri(meth)acrylates such as trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, propoxylated trimethylolpropane tri(meth)acrylate, glycerin tri(meth)acrylate, ditrimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, and dipentaerythritol tri(meth)acrylate;

Examples of such (meth)acrylates include tetrafunctional or higher (meth)acrylates such as pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, ditrimethylolpropane penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and ditrimethylolpropane hexa(meth)acrylate; and (meth)acrylates in which part or all of the above-mentioned various multifunctional (meth)acrylates have been modified with a polyoxyalkylene chain or polyester chain.

Examples of the other urethane (meth)acrylate resins include urethane (meth)acrylate resins using isocyanate compounds other than the isocyanate compound (A1) and the isocyanate compound (A2), and urethane (meth)acrylate resins using hydroxy (meth)acrylate compounds other than dipentaerythritol (meth)acrylate (B).

The epoxy (meth)acrylate resin can be, for example, a (meth)acrylate obtained by reacting various epoxy resins, such as bisphenol-type epoxy resins and novolac-type epoxy resins, with (meth)acrylic acid or a derivative thereof.

The dendrimer type (meth)acrylate resin is a resin that has a regular multi-branched structure and has a (meth)acryloyl group at the end of each branched chain, and is also called a hyperbranched type or a star polymer, in addition to a dendrimer type. Examples of such compounds include those represented by the following structural formulas (2-1) to (2-8), but are not limited to these, and any resin that has a regular multi-branched structure and has a (meth)acryloyl group at the end of each branched chain can be used.

（式中Ｒ^３は水素原子又はメチル基であり、Ｒ^４は炭素原子数１～４の炭化水素基である。）

(In the formula, ^R3 is a hydrogen atom or a methyl group, and ^R4 is a hydrocarbon group having 1 to 4 carbon atoms.)

（式中Ｒ^３は水素原子又はメチル基であり、Ｒ^４は炭素原子数１～４の炭化水素基である。）

(In the formula, ^R3 is a hydrogen atom or a methyl group, and ^R4 is a hydrocarbon group having 1 to 4 carbon atoms.)

Examples of such dendrimer-type (meth)acrylate resins include "Viscoat #1000" (weight average molecular weight (Mw) 1,500 to 2,000, average number of (meth)acryloyl groups per molecule: 14), "Viscoat 1020" (weight average molecular weight (Mw) 1,000 to 3,000), "SIRIUS 501" (weight average molecular weight (Mw) 15,000 to 23,000), and "SP-1106" (weight average molecular weight (Mw) 1,630, average number of (meth)acryloyl groups per molecule: 1), manufactured by Osaka Organic Chemical Co., Ltd. 8], SARTOMER's "CN2301" and "CN2302" [average number of (meth)acryloyl groups per molecule: 16], "CN2303" [average number of (meth)acryloyl groups per molecule: 6], "CN2304" [average number of (meth)acryloyl groups per molecule: 18], Nippon Steel & Sumikin Chemical's "ESDRIMER HU-22", Shin-Nakamura Chemical's "A-HBR-5", Daiichi Kogyo Seiyaku's "New Frontier R-1150", Nissan Chemical's "Hypertech UR-101", and other commercially available products may also be used.

The weight average molecular weight (Mw) of the dendrimer type (meth)acrylate resin is preferably in the range of 1,000 to 30,000. The average number of (meth)acryloyl groups per molecule is preferably in the range of 5 to 30.

The (meth)acryloyl group-containing acrylic resin can be, for example, one obtained by polymerizing an acrylic resin intermediate obtained by using as an essential component a (meth)acrylate monomer (α) having a reactive functional group such as a hydroxyl group, a carboxyl group, an isocyanate group, or a glycidyl group, and then reacting the resulting acrylic resin intermediate with a (meth)acrylate monomer (β) having a reactive functional group capable of reacting with the functional group to introduce a (meth)acryloyl group.

Examples of the (meth)acrylate monomer (α) having a reactive functional group include hydroxyl group-containing (meth)acrylate monomers such as hydroxyethyl (meth)acrylate and hydroxypropyl (meth)acrylate; carboxyl group-containing (meth)acrylate monomers such as (meth)acrylic acid; isocyanate group-containing (meth)acrylate monomers such as 2-acryloyloxyethyl isocyanate, 2-methacryloyloxyethyl isocyanate, and 1,1-bis(acryloyloxymethyl)ethyl isocyanate; and glycidyl group-containing (meth)acrylate monomers such as glycidyl (meth)acrylate and 4-hydroxybutyl acrylate glycidyl ether. These (meth)acrylate monomers (α) can be used alone or in combination of two or more.

The acrylic resin intermediate may be a copolymer of the (meth)acrylate monomer (α) and other polymerizable unsaturated group-containing compounds as necessary. Examples of the other polymerizable unsaturated group-containing compounds include (meth)acrylic acid alkyl esters such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate; cycloring-containing (meth)acrylates such as cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, and dicyclopentanyl (meth)acrylate; aromatic ring-containing (meth)acrylates such as phenyl (meth)acrylate, benzyl (meth)acrylate, and phenoxyethyl acrylate; silyl group-containing (meth)acrylates such as 3-methacryloxypropyltrimethoxysilane; and styrene derivatives such as styrene, α-methylstyrene, and chlorostyrene. These polymerizable unsaturated group-containing compounds can be used alone or in combination of two or more. Among these, (meth)acrylic acid alkyl esters are preferred.

When the acrylic resin intermediate is obtained by copolymerizing the (meth)acrylate monomer (α) with the other polymerizable unsaturated group-containing compound, the reaction ratio of the two is preferably in the range of 20 to 70% by mass, more preferably 30 to 60% by mass, relative to the total of the two, since the resulting acrylic resin is a (meth)acryloyl group-containing acrylic resin with excellent curing properties.

The acrylic resin intermediate can be produced by the same method as that for general acrylic resins. For example, it can be produced by polymerizing various monomers in the presence of a polymerization initiator at a temperature range of 60 to 150°C. Examples of the polymerization method include bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization. Examples of the polymerization mode include random copolymerization, block copolymerization, and graft copolymerization. When the solution polymerization method is used, it is preferable to use, for example, a ketone solvent such as methyl ethyl ketone or methyl isobutyl ketone, or a glycol ether solvent such as propylene glycol monomethyl ether, propylene glycol dimethyl ether, propylene glycol monopropyl ether, or propylene glycol monobutyl ether.

The (meth)acrylate monomer (β) is not particularly limited as long as it can react with the reactive functional group of the (meth)acrylate monomer (α), but the following combinations are preferable from the viewpoint of reactivity. That is, when the hydroxyl group-containing (meth)acrylate is used as the (meth)acrylate monomer (α), it is preferable to use an isocyanate group-containing (meth)acrylate as the (meth)acrylate monomer (β). When the carboxyl group-containing (meth)acrylate is used as the (meth)acrylate monomer (α), it is preferable to use the glycidyl group-containing (meth)acrylate as the (meth)acrylate monomer (β). When the isocyanate group-containing (meth)acrylate is used as the (meth)acrylate monomer (α), it is preferable to use the hydroxyl group-containing (meth)acrylate as the (meth)acrylate monomer (β). When the glycidyl group-containing (meth)acrylate is used as the (meth)acrylate monomer (α), it is preferable to use the carboxy group-containing (meth)acrylate as the (meth)acrylate monomer (β).

When the reaction between the acrylic resin intermediate and the (meth)acrylate monomer (β) is an esterification reaction, for example, the reaction may be carried out at a temperature range of 60 to 150°C using an appropriate esterification catalyst such as triphenylphosphine. When the reaction is a urethane reaction, the reaction may be carried out at a temperature range of 50 to 120°C while dripping the (meth)acrylate monomer (α) onto the acrylic resin intermediate.

The weight average molecular weight (Mw) of the (meth)acryloyl group-containing acrylic resin is preferably in the range of 5,000 to 80,000. The (meth)acryloyl group equivalent is preferably in the range of 100 to 500 g/equivalent.

These other photocurable compounds (R) may be used alone or in combination of two or more. When using these other photocurable compounds (R), it is preferable to use the urethane (meth)acrylate resin of the present invention in a proportion of 5 parts by mass or more, more preferably 20 parts by mass or more, and particularly preferably 80 parts by mass or more, per 100 parts by mass of the urethane (meth)acrylate resin of the present invention and the other photocurable compounds (R) combined.

Examples of the organic solvent include ketone solvents such as methyl ethyl ketone, acetone, and isobutyl ketone; cyclic ether solvents such as tetrahydrofuran and dioxolane; ester solvents such as methyl acetate, ethyl acetate, and butyl acetate; aromatic solvents such as toluene and xylene; alicyclic solvents such as cyclohexane and methylcyclohexane; alcohol solvents such as carbitol, cellosolve, methanol, isopropanol, butanol, and propylene glycol monomethyl ether; and glycol ether solvents such as alkylene glycol monoalkyl ether, dialkylene glycol monoalkyl ether, and dialkylene glycol monoalkyl ether acetate. These organic solvents can be used alone or in combination of two or more kinds. In addition, these organic solvents are mainly used for the purpose of adjusting the viscosity of the curable composition, and it is usually preferable to adjust the non-volatile content to a range of 10 to 80 mass%.

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. These ultraviolet absorbers can be used alone or in combination of two or more.

Examples of the antioxidant include hindered phenol-based antioxidants, hindered amine-based antioxidants, organic sulfur-based antioxidants, and phosphate-based antioxidants. These antioxidants can be used alone or in combination of two or more.

Examples of the silicon-based additives include polyorganosiloxanes having alkyl or phenyl groups, such as dimethylpolysiloxane, methylphenylpolysiloxane, cyclic dimethylpolysiloxane, methylhydrogenpolysiloxane, polyether-modified dimethylpolysiloxane copolymer, polyester-modified dimethylpolysiloxane copolymer, fluorine-modified dimethylpolysiloxane copolymer, and amino-modified dimethylpolysiloxane copolymer, polydimethylsiloxane having polyether-modified acrylic groups, and polydimethylsiloxane having polyester-modified acrylic groups. These silicon-based additives can be used alone or in combination of two or more kinds.

The fluorine-based additives include, for example, the "Megaface" series manufactured by DIC Corporation. These fluorine-based additives can be used alone or in combination of two or more kinds.

Examples of the silane coupling agent include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride, special aminosilane, 3-ureidopropyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, bis(triethoxysilylpropyl)tetrasulfide, 3-isocyanatepropyltriethoxysilane, allyltrichlorosilane, allyltriethoxysilane, allyltrimethoxysilane, diethoxymethylvinylsilane, trichlorovinylsilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane and other vinyl-based silane coupling agents;

Epoxy-based silane coupling agents such as diethoxy(glycidyloxypropyl)methylsilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3-glycidoxypropyltriethoxysilane;

Styrene-based silane coupling agents such as p-styryltrimethoxysilane;

(Meth)acryloxy-based silane coupling agents such as 3-methacryloxypropylmethyldimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, and 3-methacryloxypropyltriethoxysilane;

Amino-based silane coupling agents such as N-2(aminoethyl)3-aminopropylmethyldimethoxysilane, N-2(aminoethyl)3-aminopropyltrimethoxysilane, N-2(aminoethyl)3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, and N-phenyl-3-aminopropyltrimethoxysilane;

Ureido-based silane coupling agents such as 3-ureidopropyltriethoxysilane;

Chloropropyl-based silane coupling agents such as 3-chloropropyltrimethoxysilane;

Mercapto-based silane coupling agents such as 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltrimethoxysilane;

Sulfide-based silane coupling agents such as bis(triethoxysilylpropyl)tetrasulfide;

Examples include isocyanate-based silane coupling agents such as 3-isocyanate propyl triethoxy silane. These silane coupling agents can be used alone or in combination of two or more types.

Examples of the phosphate ester compound include those having a (meth)acryloyl group in the molecular structure. Commercially available products include, for example, "Kayamar PM-2" and "Kayamar PM-21" manufactured by Nippon Kayaku Co., Ltd., "Light Ester P-1M", "Light Ester P-2M", and "Light Acrylate P-1A (N)" manufactured by Kyoeisha Chemical Co., Ltd., "SIPOMER PAM 100", "SIPOMER PAM 200", "SIPOMER PAM 300", and "SIPOMER PAM 4000" manufactured by Solvay, "Viscoat #3PA" and "Viscoat #3PMA" manufactured by Osaka Organic Chemical Industry Co., Ltd., and "New Frontier S-23A" manufactured by Daiichi Kogyo Seiyaku Co., Ltd.; and "SIPOMER PAM 5000" manufactured by Solvay, which is a phosphate ester compound having an allyl ether group in the molecular structure.

Examples of the organic beads include polymethyl methacrylate beads, polycarbonate beads, polystyrene beads, polyacrylic styrene beads, silicone beads, glass beads, acrylic beads, benzoguanamine resin beads, melamine resin beads, polyolefin resin beads, polyester resin beads, polyamide resin beads, polyimide resin beads, polyethylene fluoride resin beads, polyethylene resin beads, etc. These organic beads can be used alone or in combination of two or more types. In addition, the average particle size of these organic beads is preferably in the range of 1 to 10 μm.

Examples of the inorganic fine particles include fine particles of silica, alumina, zirconia, titania, barium titanate, antimony trioxide, etc. These inorganic fine particles can be used alone or in combination of two or more kinds. The average particle size of these inorganic fine particles is preferably in the range of 95 to 250 nm, and more preferably in the range of 100 to 180 nm.

When the inorganic fine particles are contained, a dispersion aid can be used. Examples of the dispersion aid include phosphate ester compounds such as isopropyl acid phosphate, triisodecyl phosphite, and ethylene oxide modified phosphate dimethacrylate. These dispersion aids can be used alone or in combination of two or more. Examples of commercially available dispersion aids include "Kayamar PM-21" and "Kayamar PM-2" manufactured by Nippon Kayaku Co., Ltd., and "Light Ester P-2M" manufactured by Kyoeisha Chemical Co., Ltd.

[Cured product]
The cured product of the present invention is obtained by curing the active energy ray-curable composition.

Methods for curing the curable composition include, for example, a heating method and a method of irradiating with active energy rays such as ultraviolet rays.

The heating method is to heat the material in a temperature range of 60 to 200°C for 0.5 to 60 minutes to harden it.

As a method of irradiating the active energy rays, for example, in the case of ultraviolet rays, curing can be performed by using an ultraviolet lamp such as a low pressure mercury lamp, a high pressure mercury lamp, an ultra-high pressure mercury lamp, a xenon lamp, a gallium lamp, a metal halide lamp, sunlight, or an LED as an ultraviolet ray generating source.

In addition to ultraviolet light, other ionizing radiation such as electron beams, α rays, β rays, and γ rays can also be used as the active energy rays.

The amount of irradiation of the active energy rays is preferably in the range of 0.05 to 5 J/cm ² , more preferably in the range of 0.1 to 3 J/cm ² , and particularly preferably in the range of 0.1 to 1 J/cm ^2. The amount of ultraviolet irradiation is based on a value measured in a wavelength range of 300 to 390 nm using a UV checker UVR-N1 (manufactured by Japan Battery Co., Ltd.).

[Laminated film]
The laminate film of the present invention has a layer made of the above-mentioned cured product on a substrate.

The method for producing the laminated film of the present invention includes, for example, a method in which the active energy ray-curable composition is applied to at least one surface of the substrate, and then the active energy ray is irradiated.

Examples of the substrate include metal substrates, plastic substrates, glass substrates, paper substrates, wood substrates, and fibrous substrates. Among these substrates, plastic substrates are preferred because they have excellent adhesion to the active energy ray-curable composition.

Examples of materials for the plastic substrate include polyester, acrylic resin (polymethyl methacrylate, etc.), polycarbonate, acrylonitrile-butadiene-styrene copolymer (ABS resin), composite resin of ABS resin and polycarbonate, polystyrene, polyurethane, epoxy resin, polyvinyl chloride, polyamide, polyolefin (polyethylene, polypropylene, polycycloolefin (COP), etc.), triacetyl cellulose (TAC), polyimide, etc.

Examples of the plastic substrate include plastic molded products such as mobile phones, home appliances, automobile interior and exterior materials, and office automation equipment. Film substrates made of plastic can also be used.

Examples of methods for applying the active energy ray curable composition include application methods using a gravure coater, roll coater, comma coater, knife coater, air knife coater, curtain coater, kiss coater, shower coater, flow coater, spin coater, dipping, screen printing, spraying, brush coating, applicator, bar coater, etc.

The thickness of the coating film formed using the active energy ray curable composition can be adjusted as appropriate depending on the application, but is usually preferably in the range of 0.01 to 50 μm.

The laminate film of the present invention may have a functional film layer such as an anti-reflection film, a diffusion film, or a polarizing film in addition to the substrate and the layer made of the cured product.

The laminated film of the present invention has a cured coating film that is excellent in hardness, scratch resistance, flexibility, and curl resistance, and can be used as a coating layer that protects the surface of a substrate. For example, it can be suitably used as the front panel of a liquid crystal display or an organic EL display.

Examples of articles having the laminated film of the present invention include plastic molded products such as mobile phones, housings for home appliances, automobile bumpers, and office automation equipment.

The present invention will be specifically explained below with examples and comparative examples.

In this example, the hydroxyl value is an actual value measured according to the neutralization titration method of JIS K 0070 (1992).

In this example, the weight average molecular weight (Mw) was measured using gel permeation chromatography (GPC) under the following conditions:

Measuring device: Tosoh Corporation HLC-8220
Column: Tosoh Corporation guard column _HXL -H
+ Tosoh Corporation TSKgel G5000HXL
+ Tosoh Corporation TSKgel G4000HXL
+ Tosoh Corporation TSKgel G3000HXL
+ Tosoh Corporation TSKgel G2000HXL
Detector: RI (differential refractometer)
Data processing: Tosoh Corporation SC-8010
Measurement conditions: Column temperature 40°C
Solvent Tetrahydrofuran
Flow rate: 1.0 ml/min. Standard: polystyrene Sample: 100 μl of a tetrahydrofuran solution containing 0.4% by mass of resin solids filtered through a microfilter

In this example, the NCO content was measured by titration with an aqueous hydrochloric acid solution after reacting an isocyanate compound with di-n-butylamine.

(Production Example 1: Production of Isocyanate Compound (A2-3))
Into a four-neck flask, 84 parts of hexamethylene diisocyanate ("50M-HDI" manufactured by Asahi Kasei Corporation, NCO content 49.9%) and 0.04 parts by mass of dibutyltin dilaurate were added, and the flask was heated until the internal temperature reached 60° C. Then, 45.3 parts by mass of butylethylpropanediol (manufactured by KH Neochem Corporation) was added in portions over about 1 hour, and the mixture was reacted at 85° C. for 2 hours to obtain an isocyanate compound (A2-3). The NCO content of the isocyanate compound (A2-3) was 13.7%.

(Production Example 2: Production of Isocyanate Compound (A2-4))
Into a four-neck flask, 84 parts of hexamethylene diisocyanate ("50M-HDI" manufactured by Asahi Kasei Corporation, NCO content 49.9%) and 0.04 parts by mass of dibutyltin dilaurate were added, and the flask was heated until the internal temperature reached 60° C. Then, 21.5 parts by mass of propylene glycol (manufactured by AGC Inc.) was added in portions over about 1 hour, and the mixture was reacted at 85° C. for 2 hours to obtain an isocyanate compound (A2-4). The NCO content of the isocyanate compound (A2-4) was 16.3%.

(Production Example 3: Production of Isocyanate Compound (A2-5))
A four-neck flask was charged with 97 parts of 1,3-bis(isocyanatomethyl)cyclohexane (Takenate 600 manufactured by Mitsui Chemicals, Inc., NCO content 43.2%) and 0.04 parts by mass of dibutyltin dilaurate, and the flask was heated until the internal temperature reached 60° C. Then, 29.4 parts by mass of neopentyl glycol (manufactured by Mitsubishi Gas Chemical Company, Inc.) was added in portions over about 1 hour, and the mixture was allowed to react at 85° C. for 2 hours to obtain an isocyanate compound (A2-5). The NCO content of the isocyanate compound (A2-5) was 15.8%.

(Production Example 4: Production of urethane (meth)acrylate resin (1))
Into a four-neck flask, 163 parts by mass of dipentaerythritol (meth)acrylate (B1) (hydroxyl value: 125 mg KOH / g) was added. 0.6 parts by mass of dibutyltin dilaurate and 0.6 parts by mass of methoquinone were added, and the flask was heated until the internal temperature reached 60 ° C. Then, 19.1 parts by mass of hexamethylene diisocyanate (Asahi Kasei Corporation "50M-HDI", NCO content 49.9%) was added in portions over about 1 hour, and then 17.3 parts by mass of polyisocyanate of hexamethylene diisocyanate (Asahi Kasei Corporation "Duranate A201H", NCO content 17.2%) was added in portions, and the reaction was carried out at 85 ° C. for 8 hours, and it was confirmed by titration of an aqueous hydrochloric acid solution that the NCO% in the total raw materials was 0.2% or less, and 50.6 parts by mass of butyl acetate was added to obtain a urethane (meth)acrylate resin (1). The weight average molecular weight (Mw) of this urethane (meth)acrylate resin (1) was 6,000, and the theoretical value of the (meth)acryloyl group equivalent calculated from the charging ratio of the raw materials was 123 g/equivalent.

(Production Examples 5 to 9: Production of urethane (meth)acrylate resins (2) to (6))
Urethane (meth)acrylate resins (2) to (6) were obtained in the same manner as in Example 1, except that the dipentaerythritol (meth)acrylate, the isocyanate compound, and the butyl acetate were changed to the compositions and amounts shown in Table 1.

(Production Examples 10 and 11: Production of Urethane (Meth)acrylate Resins (C1) and (C2))
Urethane (meth)acrylate resins (C1) and (C2) were obtained in the same manner as in Example 1, except that the dipentaerythritol (meth)acrylate, the isocyanate compound, and the butyl acetate were changed to the compositions and amounts shown in Table 1.

The abbreviations in Table 1 indicate the following:
Compound (A1-1): Hexamethylene diisocyanate ("50M-HDI" manufactured by Asahi Kasei Corporation), NCO content 49.9%
Compound (A1-2): 1,3-bis(isocyanatomethyl)cyclohexane ("Takenate 600" manufactured by Mitsui Chemicals, Inc.), NCO content 43.2%
Compound (A2-1): Polyisocyanate of hexamethylene diisocyanate ("Duranate (registered trademark) A201H" manufactured by Asahi Kasei Corporation), NCO content 17.2%
Compound (A2-2): Polyisocyanate of hexamethylene diisocyanate ("Duranate (registered trademark) D201" manufactured by Asahi Kasei Corporation), NCO content 15.8%
Compound (A2-3): Isocyanate compound (A2-3) obtained in Production Example 1, NCO content 13.7%
Compound (A2-4): Isocyanate compound (A2-4) obtained in Production Example 2, NCO content 16.3%
Compound (A2-5): Isocyanate compound (A2-5) obtained in Production Example 3, NCO content 15.8%
Compound (B1): polyfunctional acrylate ("Aronix MT-3545" manufactured by Toagosei Co., Ltd., containing 20 to 40% by mass of dipentaerythritol hexaacrylate), hydroxyl value 125 mgKOH/g
Compound (C1): 2-hydroxyethyl (meth)acrylate ("HEA" manufactured by Osaka Organic Chemical Industry Co., Ltd.)
Compound (C2): Unsaturated fatty acid hydroxyalkyl ester modified ε-caprolactone (Daicel Corporation, "Placcel FA-2D")

(Example 1: Preparation of laminated film (1))
100 parts by mass of the urethane (meth)acrylate resin (1) obtained in Production Example 4, 6.4 parts by mass of a photopolymerization initiator (IGM's "Omnirad-184"), and 128 parts by mass of methyl ethyl ketone were mixed to obtain an active energy ray curable composition. The active energy ray curable composition obtained was then applied to a 50 μm thick polyethylene terephthalate film (hereinafter abbreviated as "PET film") using a bar coater and dried at 90°C for 1 minute. Next, under a nitrogen atmosphere, ultraviolet rays were irradiated at 100 mJ/ ^cm2 from an 80 W high pressure mercury lamp to obtain a laminated film having a 10 μm thick cured coating film on a 50 μm thick PET film.

(Examples 2 to 6: Preparation of Laminated Films (2) to (6))
Laminated films (2) to (6) were obtained in the same manner as in Example 1, except that the urethane (meth)acrylate resin (1) used in Production Example 4 was replaced with the urethane (meth)acrylate resins (2) to (6) obtained in Examples 5 to 9, respectively.

(Example 7: Preparation of laminated film (7))
A laminated film (7) was obtained in the same manner as in Example 1, except that the urethane (meth)acrylate resin (2) obtained in Example 5 and glycerin di/triacrylate ("Aronix M-920" manufactured by Toa Gosei Co., Ltd.) were used instead of the urethane (meth)acrylate resin (1) used in Production Example 4.

(Comparative Examples 1 and 2: Preparation of Laminated Films (R1) and (R2))
Laminated films (R1) and (R2) were obtained in the same manner as in Example 1, except that the urethane (meth)acrylate resin (1) used in Production Example 4 was replaced with the urethane (meth)acrylate resins (R1) and (R2) obtained in Comparative Examples 1 and 2, respectively.

The laminated films obtained in the above examples and comparative examples were used to carry out the following evaluations.

[Method of measuring coating hardness]
In the laminate films obtained in the Examples and Comparative Examples, the hardness of the cured coating film surface of the active energy ray curable composition was measured under a load of 500 g according to JIS K5600-5-4 [Scratch hardness (pencil method)]. Five measurements were made for each hardness, and the hardness at which no scratches were observed four or more times was regarded as the hardness of the cured coating film.

[Method for evaluating scratch resistance]
An abrasion test was performed in which a disk-shaped indenter with a diameter of 2.4 cm was wrapped in 0.5 g of steel wool ("Bonstar #0000" manufactured by Japan Steel Wool Co., Ltd.), a load of 500 g was applied to the indenter, and the cured coating surface of the laminated film obtained in the Examples and Comparative Examples was reciprocated 200 times. The haze values of the coating film before and after the abrasion test were measured using an automatic haze computer ("HZ-2" manufactured by Suga Test Instruments Co., Ltd.), and the scratch resistance was evaluated based on the difference (dH) between the measured values. The smaller the difference (dH), the higher the resistance to scratching.

[Flexibility evaluation method]
The laminated films obtained in the Examples and Comparative Examples were wrapped around test bars using a mandrel tester (TP Giken Co., Ltd.'s "Bending Tester"), and a test was conducted to visually check whether cracks occurred or not, and the minimum diameter of the test bar that did not cause cracks was used as the evaluation result. Test bars with diameters ranging from 2 mm to 12 mm in 1 mm increments were used.

[Evaluation method for curl resistance]
A test piece was obtained by cutting out a 5 cm square coating from the laminated film obtained in the Examples and Comparative Examples, and the lift of the four corners of the test piece from the horizontal was measured and evaluated as the average value (mm). The smaller the value, the smaller the curl and the better the curl resistance.

The evaluation results of the laminate films (1) to (7) prepared in Examples 1 to 7 and the laminate films (R1) and (R2) prepared in Comparative Examples 1 and 2 are shown in Table 2.

Examples 1 to 7 shown in Table 2 are examples of laminated films using the urethane (meth)acrylate resin of the present invention. It was confirmed that the cured coating film of the urethane (meth)acrylate resin has excellent coating hardness, and that the laminated film has excellent scratch resistance, flexibility, and curl resistance.

On the other hand, in Comparative Examples 1 and 2, which are examples in which the acrylate compound (A2) is not used as a raw material for the urethane (meth)acrylate resin, it was confirmed that although the cured coating film of the urethane (meth)acrylate resin has excellent coating film hardness, the laminated film using the urethane (meth)acrylate resin has extremely insufficient curl resistance.

Claims (10)

A urethane (meth)acrylate resin comprising, as essential reaction raw materials, an isocyanate compound (A1) that does not contain a bond derived from an isocyanate group in the molecule, an isocyanate compound (A2) that contains a bond derived from an isocyanate group in the molecule, and dipentaerythritol (meth)acrylate (B),
an equivalent ratio [(A1)/(A2)] of the isocyanate compound (A2) to the isocyanate compound (A1) in the reaction raw materials is in the range of 40/60 to 99/1;
A urethane (meth)acrylate resin, characterized in that the dipentaerythritol (meth)acrylate (B) has a hydroxyl value in the range of more than 120 mg KOH/g and not more than 150 mg KOH/g. The urethane (meth)acrylate resin according to claim 1, wherein the NCO content of the isocyanate compound (A1) is in the range of 20 to 55%, and the NCO content of the isocyanate compound (A2) is in the range of 10 to 25%. The urethane (meth)acrylate resin according to claim 1, wherein the equivalent ratio [(A1)/(A2)] of the isocyanate compound (A1) to the isocyanate compound (A2) in the reaction raw materials is in the range of 70/30 to 95/5. The urethane (meth)acrylate resin according to claim 1, further comprising a hydroxyl group-containing acrylic acid ester (C) other than the dipentaerythritol (meth)acrylate (B) as a reaction raw material. The urethane (meth)acrylate resin according to claim 1, wherein the dipentaerythritol (meth)acrylate (B) contains dipentaerythritol hexa(meth)acrylate. The urethane (meth)acrylate resin according to claim 5 , wherein the content of the dipentaerythritol hexa(meth)acrylate in the dipentaerythritol (meth)acrylate (B) is in the range of 10 to 50 mass%. An active energy ray-curable composition containing the urethane (meth)acrylate resin according to any one of claims 1 to 6 and a photopolymerization initiator. A cured product of the active energy ray-curable composition according to claim 7. A laminated film having a cured coating film made of the cured product of claim 8 on one or both sides of a substrate. The laminated film according to claim 9, wherein the thickness of the substrate is in the range of 50 to 80 μm, and the thickness of the cured coating is in the range of 5 to 20 μm.