JP6953683B2 - Urethane (meth) acrylate resin and laminated film - Google Patents

Description

The present invention relates to a urethane (meth) acrylate resin having excellent scratch resistance, curl resistance, flexibility, impact resistance, etc. in a cured coating film, a curable composition containing the same, a cured product thereof, and a laminate. Regarding film.

Plastic films manufactured using polyethylene terephthalate resin (PET), acrylic resin, polycarbonate resin, acetylated cellulose resin, etc. are used in industrial applications such as polarizing plate protective films incorporated inside flat panel displays and surface protective films for touch panels. It is often used in. Since these plastic films have insufficient performance such as the surface is easily scratched by themselves, the workability is low, and cracks and cracks are easily formed, a coat layer made of an active energy ray-curable resin or the like is usually provided on the surface. It is used to supplement these performances.

As a coating agent for reinforcing a plastic film, for example, a resin composition containing 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 Patent Document 1). The resin composition described in Patent Document 1 has a high surface hardness in a cured product and is also excellent in scratch resistance, but curls are likely to occur, and the toughness and flexibility of the coating film are not sufficient, so that an external impact is obtained. It was easy for cracks to occur.

International Publication No. 2010/146801

Therefore, the problem to be solved by the present invention is a urethane (meth) acrylate resin having excellent various performances such as scratch resistance, curl resistance, flexibility, and impact resistance in a cured coating film, and a curable composition containing the urethane (meth) acrylate resin. The present invention is to provide a cured product thereof, and a laminated film.

As a result of diligent studies to solve the above problems, the present inventor contains isophorone diisocyanate or a modified product thereof, dipentaerythritol tetra (meth) acrylate and dipentaerythritol penta (meth) acrylate, and the contents of both. The urethane (meth) acrylate resin obtained by reacting dipentaerythritol (meth) acrylate having a ratio [(b1) / (b2)] in the range of 5/95 to 30/70 as an essential component is described above. We have found a solution to the problem and have completed the present invention.

That is, in the present invention, isophorone diisocyanate or a modified product (A) thereof and dipentaerythritol (meth) acrylate (B) are used as essential reaction raw materials, and the dipentaerythritol poly (meth) acrylate (B) is used as dipenta. It contains erythritol tetra (meth) acrylate (b1) and dipentaerythritol penta (meth) acrylate (b2), and the ratio of the contents of both [(b1) / (b2)] is 5/95 to 30/70. It relates to a range of urethane (meth) acrylate resins.

The present invention further relates to a curable composition containing the urethane (meth) acrylate resin and a photopolymerization initiator.

The present invention further relates to a cured product obtained by curing the curable composition.

The present invention further relates to a laminated film having a layer made of the cured product and another plastic film layer.

According to the present invention, a urethane (meth) acrylate resin excellent in various performances such as scratch resistance, curl resistance, flexibility, and impact resistance in a cured coating film, a curable composition containing the urethane (meth) acrylate resin, and a cured product thereof. And a laminated film can be provided. The curable composition containing the urethane (meth) acrylate resin of the present invention can be suitably used as a reinforcing coating agent for various plastic films, and the laminated film obtained by using the curable composition of the present invention has resistance to resistance. It is excellent in scratch resistance and curl resistance, has high flexibility and is less likely to crack when bent or wound, and has impact resistance which is less likely to crack even when a falling object is on the film.

The urethane (meth) acrylate resin of the present invention uses isophorone diisocyanate or a modified product (A) thereof and dipentaerythritol (meth) acrylate (B) as essential reaction raw materials.

Regarding the isophorone diisocyanate or its modified product (A), the modified isophorone diisocyanate is a modified polyisocyanate compound using isophorone diisocyanate as a raw material, and for example, isocyanurate-modified obtained by isophorone diisocyanate. Examples thereof include the body, an adduct-modified product obtained by reacting isophorone diisocyanate with a polyol compound, a biuret-modified product of isophorone diisocyanate, and an allophanate-modified product of isophorone diisocyanate. In the present invention, as the isophorone diisocyanate or a modified product (A) thereof, one type may be used alone, or two or more types may be used in combination.

The dipentaerythritol (meth) acrylate (B) contains dipentaerythritol tetra (meth) acrylate (b1) and dipentaerythritol penta (meth) acrylate (b2), and the ratio of the contents of both [(b1). ) / (B2)] is in the range of 5/95 to 30/70. The dipentaerythritol (meth) acrylate (B) includes dipentaerythritol tetra (meth) acrylate (b1) and dipentaerythritol penta (meth) acrylate (b2), as well as dipentaerythritol mono (meth) acrylate and dipenta. It may contain erythritol di (meth) acrylate, dipentaerythritol tri (meth) acrylate, and dipentaerythritol hexa (meth) acrylate.

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 calculated from the area ratio of the liquid chromatography chart measured under the following conditions. The value.
[Measurement condition]
Equipment: "LCMS-2010EV" manufactured by Shimadzu Corporation
Data processing: "LCMS Solution" manufactured by Shimadzu Corporation
Column: "ODS-100V" manufactured by Tosoh Corporation (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 data in 10 ml of acetonitrile (for LC)
2. Stir with vortex for 30 seconds
3. Leave for 30 minutes
4. Calculation of area ratio used as a measurement sample by passing liquid through a 0.2 μm filtration filter: Calculated at a UV wavelength of 210 nm

Among them, dipentaerythritol tetra (meth) acrylate (b1) and dipentaerythritol penta (meth) acrylate are used because they are urethane (meth) acrylate resins having an excellent balance of surface hardness, flexibility and impact resistance in the cured coating film. It is more preferable to contain dipentaerythritol hexa (meth) acrylate (b3) in addition to (b2).

The content of dipentaerythritol tetra (meth) acrylate (b1) in the dipentaerythritol (meth) acrylate (B) is preferably in the range of 1 to 30%, and preferably in the range of 1 to 25%. More preferably, it is in the range of 3 to 20%.

The content of dipentaerythritol hexa (meth) acrylate (b3) in the dipentaerythritol (meth) acrylate (B) is preferably in the range of 1 to 60%, preferably in the range of 5 to 50%. More preferable.

Further, the hydroxyl value of the dipentaerythritol (meth) acrylate (B) is 50 to 140 mgKOH / because it is a urethane (meth) acrylate resin having an excellent balance of surface hardness, flexibility and impact resistance in the cured coating film. The range is preferably in the range of g, and more preferably in the range of 65 to 130 mgKOH / g. In the present invention, the hydroxyl value of dipentaerythritol (meth) acrylate (B) is calculated from the measured value measured according to JIS K 0070 or the composition ratio of each component calculated from the area ratio of the liquid chromatography chart. It is a calculated value.

The method for producing the dipentaerythritol (meth) acrylate (B) is not particularly limited, and examples thereof include a method for producing the dipentaerythritol (meth) acrylate (B) by subjecting it to an esterification reaction. When produced by this method, as a by-product other than the dipentaerythritol (meth) acrylate (B), a high molecular weight component (b') such as an addition reaction product of dipentaerythritol (meth) acrylate (B) and the like, etc. May be generated. The high molecular weight component (b') may be purified and removed, or the dipentaerythritol (meth) acrylate (B) crude product containing the component (b') may be used as a raw material for the urethane (meth) acrylate resin as it is. At this time, the content of the high molecular weight component (b') in the crude product of dipentaerythritol (meth) acrylate (B) is preferably in the range of 1 to 20% by mass.

Further, the hydroxyl value of the dipentaerythritol (meth) acrylate (B) crude product is 60 because it is a urethane (meth) acrylate resin having an excellent balance of surface hardness, flexibility and impact resistance in the cured coating film. It is preferably in the range of ~ 150 mgKOH / g. In the present invention, the hydroxyl value of dipentaerythritol (meth) acrylate (B) is an actually measured value measured according to JIS K 0070.

The urethane (meth) acrylate resin uses the isophorone diisocyanate or its modified product (A) and dipentaerythritol (meth) acrylate (B) as essential reaction raw materials, but compounds other than these may be used as reaction raw materials. .. Specifically, in addition to the isophorone diisocyanate or its modified product (A) and dipentaerythritol (meth) acrylate (B), other polyisocyanate compound (C) and other monohydroxy (meth) acrylate compound ( Examples thereof include those obtained by reacting D) and other polyol compounds (E).

The other polyisocyanate compound (C) is an aliphatic diisocyanate compound such as butane diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate; norbornan diisocyanate. , Alicyclic diisocyanate compounds such as hydrogenated xylylene diisocyanate and hydrogenated diphenylmethane diisocyanate; aromatic diisocyanate compounds such as tolylene diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthalenedi isocyanate; Polymethylenepolyphenylpolyisocyanate having a repeating structure represented by the structural formula (1); examples thereof include isocyanurate-modified products, biuret-modified products, and allophanate-modified products. Each of these may be used alone, or two or more types may be used in combination.

［式中、Ｒ^３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^４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, R ³ is independently either a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. R ⁴ is either an alkyl group having 1 to 4 carbon atoms independently, or a bond point connected to a structural site represented by the structural formula (1) via a methylene group marked with *. m is an integer of 0 or 1-3, and l is an integer of 1 or more. ]

When the other polyisocyanate compound (C) is used, the effect of the present invention is sufficiently exhibited, so that the isophorone diisocyanate or its modified product (A) and the other polyisocyanate compound (C) are used. The ratio of the isophorone diisocyanate or its modified product (A) to the total mass is preferably 30% by mass or more, and more preferably 50% by mass or more.

The other monohydroxy (meth) acrylate compound (D) is, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, glycerindi (meth) acrylate. , Trimethylol propandi (meth) acrylate, pentaerythritol tri (meth) acrylate and other aliphatic (meth) acrylate compounds; 4-hydroxyphenyl acrylate, β-hydroxyphenethyl acrylate, 4-hydroxyphenethyl acrylate, acrylate Arocyclic ring-containing (meth) acrylate compounds such as 1-phenyl-2-hydroxyethyl, 3-hydroxy-4-acetylphenyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate; Polyether-modified (meth) acrylate compounds obtained by ring-open polymerization with various cyclic ether compounds such as propylene oxide, tetrahydrofuran, ethyl glycidyl ether, propyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, allyl glycidyl ether; Examples thereof include lactone-modified (meth) acrylate compounds obtained by polycondensation of a meta) acrylate compound and a lactone compound such as ε-caprolactone. Each of these may be used alone, or two or more types may be used in combination. Of these, an aliphatic (meth) acrylate compound, a modified product thereof, or a modified lactone is preferable because it is a urethane (meth) acrylate resin having excellent flexibility and impact resistance in a cured product.

The other polyol compound (E) is, for example, ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 3-methyl-1,3-butane. Diol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, glycerin, glycerin mono (meth) acrylate, trimethylolethane, trimethylolmethane mono (meth) acrylate, trimethylolpropane, trimethylolpropane mono Polyol monomers such as (meth) acrylate, pentaerythritol mono (meth) acrylate, pentaerythritol di (meth) acrylate; the polyol monomer and succinic acid, adipic acid, azelaic acid, sebacic acid, terephthalic acid, isophthalic acid, orthophthalic acid. , Tetrahydrophthalic acid, hexahydrophthalic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, polyester polyol obtained by cocondensation with dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid; , Ε-caprolactone, δ-valerolactone, 3-methyl-δ-valerolactone and other lactone-type polyester polyols obtained by polycondensation reaction; the polyol monomer and ethylene oxide, propylene oxide, tetrahydrofuran, ethylglycidyl. Examples thereof include a polyether polyol obtained by ring-opening polymerization with a cyclic ether compound such as ether and propylglycidyl ether. Each of these polyol compounds may be used alone, or two or more kinds may be used in combination.

In the method for producing a urethane (meth) acrylate resin of the present invention, for example, the isophorone diisocyanate or its modified product (A) and dipentaerythritol (meth) acrylate (B) are combined with the isophorone diisocyanate or its modified product (A). The molar ratio [(NCO) / (OH)] of the isocyanate group of the dipentaerythritol (meth) acrylate (B) to the hydroxyl group of the dipentaerythritol (meth) acrylate (B) is in the range of 1 / 0.95 to 1 / 1.05. Examples thereof include a method of using a ratio and using a known and commonly used urethanization catalyst within a temperature range of 20 to 120 ° C., if necessary.

Further, the other polyisocyanate compound (C) and the other monohydroxy (meth) acrylate compound (D) together with the isophorone diisocyanate or a modified product (A) thereof and the dipentaerythritol (meth) acrylate (B). ), When the other polyol compound (E) is reacted, a method of reacting these three components at once may be used, or the polyisocyanate component and the polyol component are first reacted to obtain an intermediate, and then the mono. A method of reacting the alcohol component or a method of first reacting the polyisocyanate component with the monoalcohol component to obtain an intermediate and then reacting the polyol component may be used. The reaction ratio of each component is such that the total molar ratio [(NCO) / (OH)] of the isocyanate group of the polyisocyanate component and the hydroxyl group of the alcohol component is in the range of 1 / 0.95 to 1 / 1.05. It is preferable that the ratio is as follows.

The (meth) acryloyl group equivalent of the urethane (meth) acrylate resin of the present invention is in the range of 100 to 500 g / eq because it is a urethane (meth) acrylate resin having excellent curability and high surface hardness in the cured coating film. Is preferable. In the present invention, the (meth) acryloyl group equivalent of the urethane (meth) acrylate resin is a value calculated as a theoretical value from the reaction raw material.

Further, the weight average molecular weight (Mw) of the urethane (meth) acrylate resin is in the range of 2,000 to 60,000 because it is a urethane (meth) acrylate resin having an excellent balance of each performance in the cured product. Is preferable.

In the present invention, the weight average molecular weight (Mw) is a value measured by gel permeation chromatography (GPC) under the following conditions.

Measuring device; HLC-8220GPC manufactured by Tosoh Corporation
Column; TSK-GUARDCOLUMN SuperHZ-L manufactured by Tosoh Corporation
+ TSK-GEL SuperHZM-M x 4 manufactured by Tosoh Corporation
Detector; RI (Differential Refractometer)
Data processing; Multi-station GPC-8020modelII manufactured by Tosoh Corporation
Measurement conditions; column temperature 40 ° C
Solvent tetrahydrofuran
Flow velocity 0.35 ml / min Standard; Monodisperse polystyrene sample; 0.2 mass% tetrahydrofuran solution in terms of resin solid content filtered through a microfilter (100 μl)

The curable composition of the present invention contains the urethane (meth) acrylate resin and a photopolymerization initiator. The photopolymerization initiator is, for example, benzophenone, 3,3'-dimethyl-4-methoxybenzophenone, 4,4'-bisdimethylaminobenzophenone, 4,4'-bisdiethylaminobenzophenone, 4,4'-dichloro. Various benzophenones such as benzophenone, Michler's ketone, 3,3', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone;

Xanthones, thioxanthones such as xanthones, thioxanthones, 2-methylthioxanthones, 2-chlorothioxanthones, 2,4-diethylthioxanthones; various acyloin ethers such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether;

Α-diketones such as benzyl and diacetyl; sulfides such as tetramethylthiuram disulfide and p-tolyldisulfide; various benzoic acids such as 4-dimethylaminobenzoic acid and ethyl 4-dimethylaminobenzoate;

3,3'-carbonyl-bis (7-diethylamino) coumarin, 1-hydroxycyclohexylphenylketone, 2,2'-dimethoxy-1,2-diphenylethane-1-one, 2-methyl-1- [4 -(Methylthio) Phenyl] -2-morpholinopropane-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butane-1-one, 2-hydroxy-2-methyl-1-one Phenylpropan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) phenylphosphenyl oxide, 1- [4- (2-hydroxyethoxy) phenyl] -2- Hydroxy-2-methyl-1-propane-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, methyl o-benzoylbenzoate, bis (4-Dimethylaminophenyl) ketone, p-dimethylaminoacetophenone, α, α-dichloro-4-phenoxyacetophenone, pentyl-4-dimethylaminobenzoate, 2- (o-chlorophenyl) -4,5-diphenylimidazolyluni amount Body, 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-triazine anthraquinone, 2-t-butyl anthraquinone, 2-amyl anthraquinone, β-chloroanthraquinone and the like. Each of these may be used alone, or two or more types may be used in combination.

Among the photopolymerization initiators, 1-hydroxycyclohexylphenylketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy- 2-Methyl-1-propane-1-one, thioxanthone and thioxanthone derivative, 2,2'-dimethoxy-1,2-diphenylethane-1-one, 2,4,6-trimethylbenzoyldiphenylphosphenyl oxide, bis (2) , 4,6-trimethylbenzoyl) phenylphosphenyl oxide, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1- (4-morpholino) By using one or more mixed systems selected from the group of phenyl) -butane-1-one, a curable composition that exhibits activity against light of a wider range of wavelengths and has high curability can be obtained. Therefore, it is preferable.

Commercially available products of the photopolymerization initiator include, for example, "Irgacure-184", "Irgacure-149", "Irgacure-261", "Irgacure-369", "Irgacure-500", and "Irgacure-" manufactured by Ciba Specialty Chemicals. 651, "Irgacure-754", "Irgacure-784", "Irgacure-819", "Irgacure-907", "Irgacure-1116", "Irgacure-1664", "Irgacure-1700", "Irgacure-1800" , "Irgacure-1850", "Irgacure-2959", "Irgacure-4043", "DaroCure-1173"; "Lucillin TPO" manufactured by BASF; "Kayacure-DETX", "Kayacure-MBP" manufactured by Nippon Kayaku Co., Ltd. , "Kayacure-DMBI", "Kayacure-EPA", "Kayacure-OA"; "BiCure-10", "BiCure-55" manufactured by Stofa Chemical Co., Ltd .; 1000 ”;“ Deep ”manufactured by Apjon;“ Quantacure-PDO ”,“ Quantacure-ITX ”,“ Quantacure-EPD ”manufactured by Ward Brenkinsop, and the like.

The amount of the photopolymerization initiator added is preferably an amount that can sufficiently exert the function as the photopolymerization initiator and does not cause precipitation of crystals or deterioration of the physical characteristics of the coating film. It is preferably used in the range of 0.05 to 20 parts by mass, and particularly preferably in the range of 0.1 to 10 parts by mass with respect to 100 parts by mass of the curable composition.

The curable composition of the present invention may contain various photosensitizers in addition to the photopolymerization initiator. Examples of the photosensitizer include amines, ureas, sulfur-containing compounds, phosphorus-containing compounds, chlorine-containing compounds or nitriles, and other nitrogen-containing compounds.

The curable composition of the present invention further comprises other photocurable compounds other than the urethane (meth) acrylate resin of the present invention, an organic solvent, an ultraviolet absorber, an antioxidant, a silicon-based additive, and a fluorine-based additive. It may contain an agent, a silane coupling agent, organic beads, inorganic fine particles, an inorganic filler, a rheology control agent, a defoaming agent, an antifogging agent, a colorant and the like.

The other photocurable compounds include, for example, various (meth) acrylate monomers, other urethane (meth) acrylate resins other than the urethane (meth) acrylate resin of the present invention, epoxy (meth) acrylate resins, and the like. Can be mentioned.

The (meth) acrylate monomer includes, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, n-butyl (meth) acrylate, and isobutyl (meth) acrylate. ) Acrylate, t-butyl (meth) acrylate, glycidyl (meth) acrylate, acryloylmorpholine, N-vinylpyrrolidone, tetrahydroflufreele acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isobornyl (meth) Acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, benzyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 3-methoxy Butyl (meth) acrylate, ethylcarbitol (meth) acrylate, phosphoric acid (meth) acrylate, ethylene oxide-modified phosphoric acid (meth) acrylate, phenoxy (meth) acrylate, ethylene oxide-modified phenoxy (meth) acrylate, propylene oxide-modified phenoxy (Meta) acrylate, nonylphenol (meth) acrylate, ethylene oxide-modified nonylphenol (meth) acrylate, propylene oxide-modified nonylphenol (meth) acrylate, methoxydiethylene glycol (meth) acrylate, methoxypolythylene glycol (meth) acrylate, methoxypropylene glycol (meth) ) Acrylate, 2- (meth) acryloyloxyethyl-2-hydroxypropylphthalate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 2- (meth) acryloyloxyethyl hydrogen phthalate, 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, adamantyl Mono (meth) acrylates such as mono (meth) acrylates;

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, Neopentyl glycol di (meth) acrylate ethoxylated, Neopentyl glycol di (meth) acrylate of hydroxypivalate, Glycerindi (meth) acrylate, Trimethylol Di (meth) acrylates such as propanedi (meth) acrylates and pentaerythritol di (meth) acrylates;

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

Pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, ditrimethylolpropane penta (meth) acrylate, dipentaerythritol hexa (meth) ) Acrylate, ditrimethylolpropane hexa (meth) acrylate, or other tetrafunctional (meth) acrylate;

Examples thereof include (meth) acrylates in which some or all of the above-mentioned various polyfunctional (meth) acrylates are modified with a polyoxyalkylene chain or a polyester chain.

The other urethane (meth) acrylate resin is, for example, a urethane (meth) acrylate resin using a compound other than the isophorone diisocyanate or a modified product (A) thereof as a polyisocyanate compound, or dipenta as a hydroxy (meth) acrylate compound. Examples thereof include urethane (meth) acrylate resin using a compound other than erythritol (meth) acrylate (B).

Examples of the epoxy (meth) acrylate resin include compounds obtained by reacting various epoxy resins such as bisphenol type epoxy resin and novolak type epoxy resin with (meth) acrylic acid or derivatives thereof to form (meth) acrylate.

These other photocurable compounds may be used alone or in combination of two or more. Above all, it is preferable to use various (meth) acrylate monomers because the composition has excellent curability. When these other photocurable compounds are used, the urethane (meth) acrylate resin of the present invention is 5 parts by mass in a total of 100 parts by mass of the urethane (meth) acrylate resin of the present invention and other photocurable compounds. It is preferable to use it in a ratio of 20 parts by mass or more, and it is particularly preferable to use it in a ratio of 20 parts by mass or more.

The organic solvent is, for example, acetone, methyl ethyl ketone, methyl isobutyl ketone (ketone solvent such as); cyclic ether solvent such as tetrahydrofuran, dioxolane; ester such as methyl acetate, ethyl acetate, butyl acetate; aromatic solvent such as toluene, xylene; Alcohol solvents such as carbitol, cellosolve, methanol, isopropanol, butanol, and propylene glycol monomethyl ether; glycol ether solvents such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, and propylene glycol monopropyl ether can be mentioned. Each of these may be used alone, or two or more types may be used in combination.

These organic solvents are mainly used for the purpose of adjusting the viscosity of the curable composition, but it is usually preferable to adjust the non-volatile content in the range of 10 to 80% by mass.

The ultraviolet absorber is, 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 derivatives such as triazine, 2- (2'-xanthencarboxy-5'-methylphenyl) benzotriazole, 2- (2'-o-nitrobenzyloxy-5'-methylphenyl) benzotriazole, 2- Examples thereof include xanthencarboxy-4-dodecyloxybenzophenone and 2-o-nitrobenzyloxy-4-dodecyloxybenzophenone. Each of these may be used alone, or two or more types may be used in combination.

Examples of the antioxidant include hindered phenol-based antioxidants, hindered amine-based antioxidants, organic sulfur-based antioxidants, phosphoric acid ester-based antioxidants, and the like. Each of these may be used alone, or two or more types may be used in combination.

The silicon-based additive includes, for example, dimethylpolysiloxane, methylphenylpolysiloxane, cyclic dimethylpolysiloxane, methylhydrogenpolysiloxane, polyether-modified dimethylpolysiloxane copolymer, polyester-modified dimethylpolysiloxane copolymer, and fluorine-modified dimethyl. Examples include polyorganosiloxane having an alkyl group or a phenyl group such as a polysiloxane copolymer and an amino-modified dimethylpolysiloxane copolymer, polydimethylsiloxane having a polyether-modified acrylic group, and polydimethylsiloxane having a polyester-modified acrylic group. Be done. Each of these may be used alone, or two or more types may be used in combination.

Examples of the fluorine-based additive include DIC Corporation's "Megafuck" series. Each of these may be used alone, or two or more types may be used in combination.

The silane coupling agent includes, for example, vinyl trichlorosilane, vinyl trimethoxysilane, vinyl triethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-. Glycydoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyl Diethoxysilane, 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-Dimethyl butylidene) propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N- (vinylbenzyl) -2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride, special aminosilane, 3-ureido Propyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, bis (triethoxysilylpropyl) tetrasulfide, 3-isocyandiapropyltriethoxysilane, allyltrichlorosilane , Allyltriethoxysilane, allyltrimethoxysilane, diethoxymethylvinylsilane, trichlorovinylsilane, vinyltricrolsilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, and other vinyl-based silane coupling agents. ;

Diethoxy (glycidyloxypropyl) methylsilane, 2- (3,4 epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-bricidoxypropyl Epoxy-based silane coupling agents such as triethoxysilane;

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

3-Methacryloxypropylmethyldimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, etc. (meth) Acryloxy-based silane coupling agent;

N-2 (aminoethyl) 3-aminopropylmethyldimethoxysilane, N-2 (aminoethyl) 3-aminopropyltrimethoxysilane, N-2 (aminoethyl) 3-aminopropyltriethoxysilane, 3-aminopropyltri Amino-based silane couplings such as methoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N-phenyl-3-aminopropyltrimethoxysilane Agent;

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

3-Chloropropyltrimethoxysilane, a chloropropyl-based silane coupling agent;

3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxinesilane, etc., mercapro-based silane coupling agents;

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

Examples thereof include isocyanate-based silane coupling agents such as 3-isocyanatepropyltriethoxysilane. Each of these may be used alone, or two or more types may be used in combination.

The organic beads include, for example, polymethyl methacrylate beads, polycarbonate beads, polystyrene beads, polyacrylic styrene beads, silicone beads, glass beads, acrylic beads, benzoguanamine resin beads, melamine resin beads, and polyolefin resin beads. Examples thereof include polyester resin beads, polyamide resin beads, polyimide resin beads, polyfluorinated ethylene resin beads, and polyethylene resin beads. Each of these may be used alone, or two or more types may be used in combination. 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 such as silica, alumina, zirconia, titania, barium titanate, and antimony trioxide. Each of these may be used alone, or two or more types may be used in combination. 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. Further, when these inorganic fine particles are contained, a dispersion auxiliary agent may be further used, and the dispersion auxiliary agent is, for example, a phosphoric acid ester such as isopropylacid phosphate, triisodecylphosphite, or ethyleneoxide-modified dimethacrylate phosphate. Examples include compounds. Each of these may be used alone, or two or more types may be used in combination.

Examples of commercially available products of the dispersion aid include "Kajama PM-21" and "Kajama PM-2" manufactured by Nippon Kayaku Co., Ltd., and "Light Ester P-2M" manufactured by Kyoeisha Chemical Co., Ltd.

The curable composition of the present invention can be used for coating applications, and the coating material is applied as a coating layer that protects the surface of the substrate by applying it on various substrates and irradiating it with active energy rays to cure it. be able to. In this case, the curable composition of the present invention may be directly applied to the surface protection member and used, or the one applied on the plastic film may be used as the protective film. Alternatively, the curable composition of the present invention may be applied onto a plastic film to form a coating film, which may be used as an optical film such as an antireflection film, a diffusion film, and a prism sheet. Since the cured coating film of the curable composition of the present invention has a feature of high surface hardness and excellent flexibility and impact resistance, it is applied on various types of plastic films with a thickness suitable for the intended use and is a protective film. It can be used for various purposes and as a film-shaped molded product.

The plastic film is, for example, a plastic film made of polycarbonate, polymethylmethacrylate, polystyrene, polyester, polyolefin, cycloolefin, epoxy resin, melamine resin, triacetylcellulose resin, ABS resin, AS resin, norbornene resin, polyimide resin and the like. And plastic sheets.

Of the above plastic films, the triacetyl cellulose film is a film that is particularly preferably used for polarizing plates of liquid crystal displays, but since it is generally as thin as 40 to 100 μm, it has a surface even when a hard coat layer is installed. It is difficult to increase the hardness sufficiently, and it is easy to curl large. The coating film made of the curable composition of the present invention has the effect of having high surface hardness and excellent curl resistance, flexibility, transparency, and impact resistance even when a triacetyl cellulose film is used as a base material. Can be preferably used. When the triacetyl cellulose film is used as a base material, the coating amount when applying the curable composition of the present invention is such that the film thickness after drying is in the range of 1 to 20 μm, preferably in the range of 2 to 10 μm. It is preferable to apply to. Examples of the coating method at that time include bar coater coating, Mayer bar coating, air knife coating, gravure coating, reverse gravure coating, offset printing, flexographic printing, screen printing method and the like.

Among the above plastic films, the polyester film includes, for example, polyethylene terephthalate, and the thickness thereof is generally about 20 to 300 μm. It is a film used for various purposes such as touch panel displays because it is inexpensive and easy to process, but it is very soft and it is difficult to sufficiently increase the surface hardness even when a hard coat layer is installed. When the polyethylene film is used as a base material, the coating amount when the curable composition of the present invention is applied is such that the film thickness after drying is in the range of 1 to 100 μm, preferably 1 to 20 μm, depending on the application. It is preferable to apply so as to be within the range. In general, a cured coating film having a thickness of more than 20 μm tends to be larger and more likely to curl than when the film thickness is thin. Even when it is applied with a relatively high film thickness exceeding the above, curling is unlikely to occur, and it can be preferably used. Examples of the coating method at that time include bar coater coating, Mayer bar coating, air knife coating, gravure coating, reverse gravure coating, offset printing, flexographic printing, screen printing method and the like.

Among the above plastic films, the polymethylmethacrylate film is generally relatively thick and durable with a thickness of about 50 to 2,000 μm, and is therefore suitable for applications requiring particularly high surface hardness such as front plate applications for liquid crystal displays. It is a film used for. When the polymethylmethacrylate film is used as a base material, the coating amount when applying the curable composition of the present invention is in the range of 1 to 100 μm, preferably 1 to 100 μm, depending on the intended use. It is preferable to apply the coating so as to have a range of 20 μm. Examples of the coating method at that time include bar coater coating, Mayer bar coating, air knife coating, gravure coating, reverse gravure coating, offset printing, flexographic printing, screen printing method and the like.

Further, among the above plastic films, cycloolefin polymer films are generally known to be vulnerable to lateral forces such as tearing and have poor fold resistance, but in recent years, from the viewpoint of transparency and heat resistance, they have been used. The area of use is expanding. The cured coating film obtained from the curable composition of the present invention can effectively enhance its flexibility and impact resistance even in such a fragile film. From the viewpoint of preferably exhibiting such an effect, the thickness of the cured coating film is preferably adjusted in the range of 1 to 10 μm. Examples of the coating method at that time include bar coater coating, Mayer bar coating, air knife coating, gravure coating, reverse gravure coating, offset printing, flexographic printing, screen printing method and the like.

Examples of the active energy rays irradiated when the curable composition of the present invention is cured to form a coating film include ultraviolet rays and electron beams. When cured by ultraviolet rays, an ultraviolet irradiation device having a xenon lamp, a high-pressure mercury lamp, a metal halide lamp, an LED, or the like is used as a light source, and the amount of light, the arrangement of the light source, and the like are adjusted as necessary. When a high-pressure mercury lamp is used, it is preferable to cure one lamp having a light amount usually in the range of 80 to 160 W / cm at a transport speed of 5 to 50 m / min. On the other hand, when curing with an electron beam, it is preferable to cure with an electron beam accelerator having an acceleration voltage usually in the range of 10 to 300 kV at a transport speed of 5 to 50 m / min.

Further, the base material to which the curable composition of the present invention is applied is suitably used not only as a plastic film but also as a surface coating agent for various plastic molded products such as mobile phones, electric appliances, bumpers of automobiles and the like. be able to. In this case, examples of the method for forming the coating film include a coating method, a transfer method, and a sheet bonding method.

The coating method is a method in which the paint is spray-coated, or a molded product is coated as a top coat using a printing device such as a curtain coater, a roll coater, or a gravure coater, and then irradiated with active energy rays to cure. be.

The laminated film of the present invention has a cured coating film or the like of the curable composition of the present invention and a plastic film layer, and also has a functional film layer such as an antireflection film, a diffusion film and a polarizing film. You may do it. These various layer configurations may be formed by a method in which a resin raw material is directly applied and dried or cured, or may be formed by a method in which the resin raw materials are bonded via an adhesive layer.

Hereinafter, the present invention will be described in more detail with reference to specific production examples and examples, but the present invention is not limited to these examples. All parts and% in the example are based on mass unless otherwise specified.

In this example, the weight average molecular weight (Mw) is a value measured under the following conditions using a gel permeation chromatograph (GPC).

Measuring device; HLC-8220 manufactured by Tosoh Corporation
Column; Guard column H _XL- H manufactured by Tosoh Corporation
+ TSKgel G5000HXL manufactured by Tosoh Corporation
+ TSKgel G4000HXL manufactured by Tosoh Corporation
+ TSKgel G3000HXL manufactured by Tosoh Corporation
+ TSKgel G2000HXL manufactured by Tosoh Corporation
Detector; RI (Differential Refractometer)
Data processing: SC-8010 manufactured by Tosoh Corporation
Measurement conditions: Column temperature 40 ° C
Solvent tetrahydrofuran
Flow velocity 1.0 ml / min Standard; Polystyrene sample; 0.4 mass% tetrahydrofuran solution in terms of resin solid content filtered through a microfilter (100 μl)

In this example, the liquid chromatography chart was measured under the following conditions.
[Measurement condition]
Equipment: "LCMS-2010EV" manufactured by Shimadzu Corporation
Data processing: "LCMS Solution" manufactured by Shimadzu Corporation
Column: "ODS-100V" manufactured by Tosoh Corporation (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 data in 10 ml of acetonitrile (for LC)
2. Stir with vortex for 30 seconds
3. Leave for 30 minutes
4. Calculation of area ratio to be used as a measurement sample by passing liquid through a 0.2 μm filtration filter: Calculated at a UV wavelength of 210 nm

Production Example 1 Production of Dipentaerythritol Polyacrylate (B1) Crude Product In a flask equipped with a thermometer, a stirrer, and a condenser, 300 g of acrylic acid, 180 g of dipentaerythritol, 15 g of sulfuric acid, 1.5 g of cupric chloride, 300 g of toluene was charged. The temperature was raised to 105 ° C. with stirring, and the reaction was carried out at the same temperature for 12 hours while refluxing the system. The amount of water produced was 68.5 g. 425 g of toluene was added to the reaction mixture, and the mixture was washed with 200 g of distilled water. Further, a 20% aqueous sodium hydroxide solution was added to neutralize the reaction mixture, and the mixture was washed with 100 g of distilled water. After adding 500 ppm of hydroquinone monomethyl ether to the resin solid content, toluene was distilled off to obtain dipentaerythritol poly (meth) acrylate (B1). The hydroxyl value of the crude product of dipentaerythritol polyacrylate (B1) is 88 mgKOH / g, the content of dipentaerythritol tetraacrylate (b1) calculated from the area ratio of the liquid chromatography chart is 7.2%, and dipentaerythritol. The content of pentaacrylate (b2) was 48.3%, the content of dipentaerythritol hexaacrylate (b3) was 30.7%, and the content of high molecular weight component (b') was 13.8%. The hydroxyl value of dipentaerythritol polyacrylate (B1) calculated from the content ratio of each component is 79.9 mgKOH / g.

Production Examples 2 to 4 Dipentaerythritol Polyacrylates (B2) to (B4) Production of crude product Dipenta in the same manner as in Production Example 1 except that the amount of acrylic acid charged and the reaction time were changed as shown in Table 1. Crude products of erythritol polyacrylates (B2) to (B4) were obtained. Dipentaerythritol polyacrylate (B2) to (B4) Dipentaerythritol poly acrylate calculated from the hydroxyl value of the crude product, the content of each component calculated from the area ratio of the liquid chromatography chart, and the content ratio of each component. Table 1 shows the hydroxyl values of the acrylates (B2) to (B4).

Example 1 Urethane (meth) acrylate resin (1) Production of composition In a flask equipped with a thermometer, a stirrer, and a condenser, 638 g of the crude product of dipentaerythritol polyacrylate (B1) obtained in Production Example 1 and dibutyl 0.2 g of tin dilaurate and 0.2 g of hydroquinone were added, and stirring was started. The flask was heated until the internal temperature reached 50 ° C., and 111 g of isophorone diisocyanate was added in portions over about 1 hour. After reacting at 80 ° C. for 3 hours and confirming the disappearance of the isocyanate group on the infrared absorption spectrum, the non-volatile content was adjusted to 80% by mass using butyl acetate to prepare the urethane (meth) acrylate resin (1) composition. Obtained. The acryloyl group equivalent of the urethane (meth) acrylate resin (1) calculated from the raw material charging ratio was 117 g / equivalent, and the weight average molecular weight (Mw) was 3,800.

Example 2 Production of Urethane (Meta) Acrylate Resin (2) Composition In a flask equipped with a thermometer, a stirrer, and a condenser, 524 g of the crude product of dipentaerythritol polyacrylate (B2) obtained in Production Example 2, dibutyl 0.2 g of tin dilaurate and 0.2 g of hydroquinone were added, and stirring was started. The flask was heated until the internal temperature reached 50 ° C., and 111 g of isophorone diisocyanate was added in portions over about 1 hour. After reacting at 80 ° C. for 3 hours and confirming the disappearance of the isocyanate group on the infrared absorption spectrum, the non-volatile content was adjusted to 80% by mass using butyl acetate to prepare the urethane (meth) acrylate resin (2) composition. Obtained. The acryloyl group equivalent of the urethane (meth) acrylate resin (2) calculated from the raw material charging ratio was 116 g / equivalent, and the weight average molecular weight (Mw) was 4,400.

Example 3 Production of Urethane (Meta) Acrylate Resin (3) Composition In a flask equipped with a thermometer, a stirrer, and a condenser, 432 g of the crude product of dipentaerythritol polyacrylate (B3) obtained in Production Example 2, dibutyl 0.2 g of tin dilaurate and 0.2 g of hydroquinone were added, and stirring was started. The flask was heated until the internal temperature reached 50 ° C., and 111 g of isophorone diisocyanate was added in portions over about 1 hour. After reacting at 80 ° C. for 3 hours and confirming the disappearance of the isocyanate group on the infrared absorption spectrum, the non-volatile content was adjusted to 80% by mass using butyl acetate to prepare the urethane (meth) acrylate resin (3) composition. Obtained. The acryloyl group equivalent of the urethane (meth) acrylate resin (3) calculated from the raw material charging ratio was 126 g / equivalent, and the weight average molecular weight (Mw) was 7,800.

Comparative Production Example 1 Production of Urethane (Meta) Acrylate Resin (1') Composition In a flask equipped with a thermometer, a stirrer, and a condenser, 684 g of the crude product of dipentaerythritol polyacrylate (B4) obtained in Production Example 4 , 0.2 g of dibutyltin dilaurate, and 0.2 g of hydroquinone were added, and stirring was started. The flask was heated until the internal temperature reached 50 ° C., and 84 g of hexamethylene diisocyanate (“Duranate 50M-HDI” manufactured by Asahi Kasei Chemicals Co., Ltd.) was added in portions over about 1 hour. After reacting at 80 ° C. for 3 hours and confirming the disappearance of the isocyanate group by infrared absorption spectrum, the non-volatile content was adjusted to 80% by mass using butyl acetate to prepare a urethane (meth) acrylate resin (1') composition. Got The acryloyl group equivalent of the urethane (meth) acrylate resin (1') calculated from the raw material charging ratio was 112 g / equivalent, and the weight average molecular weight (Mw) was 3,700.

Examples 4 to 6 and Comparative Example 1
125 parts by mass of the urethane (meth) acrylate resin composition obtained in Examples 1 and 2 and Comparative Production Example, 4 parts by mass of the photoinitiator (“Irgacure # 184” manufactured by Ciba Specialty Chemicals), and 75 parts by mass of methyl ethyl ketone were mixed. , A curable composition was obtained. This was applied on a PET film having a thickness of 100 μm with a bar coater, and dried at 80 ° C. for 2 minutes. Next, under a nitrogen atmosphere, ultraviolet rays were ^{irradiated at 300 mJ / cm 2} with an 80 W high-pressure mercury lamp to obtain a laminated film having a cured coating film having a film thickness of 5 μm on the PET film. Various evaluation tests were carried out on this laminated film by the following methods. The results are shown in Table 2.

Pencil hardness test For the laminated film, the pencil hardness of the cured coating film surface of the curable composition was measured under a load condition of 500 g in accordance with JIS K5600-5-4. The hardness of each hardness was measured 5 times, and the hardness at which the measurement was not scratched 4 times or more was defined as the hardness of the cured coating film.

Scratch resistance test Steel wool (“Bonster # 0000” manufactured by Nippon Steel Wool Co., Ltd.) is wrapped in a disk-shaped indenter with a diameter of 2.4 cm, and a load of 500 g is applied to the indenter to form a laminated film. A wear test was carried out in which the surface of the cured coating film was reciprocated 200 times. The haze value of the coating film before and after the abrasion test was measured using an automatic haze computer (“HZ-2” manufactured by Suga Test Instruments Co., Ltd.), and the scratch resistance was evaluated by the difference value (dH) between them. The smaller the difference value, the higher the resistance to scratches.

Flexibility test A mandrel tester (“bending tester” manufactured by TP Giken Co., Ltd.) is used to wrap the laminated film around a test rod and perform a test to visually check whether or not cracks occur. The minimum diameter of was used as the evaluation result. The test rods used were those having a diameter of 2 mm to 6 mm in 1 mm increments.

Curl resistance test A 5 cm square coating film was cut out from the laminated film to obtain a test piece, and the horizontal lift of the four corners of the test piece was measured and evaluated by the average value (mm). The smaller the value, the smaller the curl and the better the curl resistance.

Impact resistance test The test was conducted with reference to JIS K5600-5-3. Specifically, it is as follows.
[Device]
Weight: A steel ball for ball bearings (mass 300.0 ± 0.5 g, diameter 25.40 mm, grade 60) specified in JIS B 1501 "Steel balls for five bearings" hung with a thread at the tip.
Steel table: A steel table with a length of 300 mm, a width of 200 mm, and a thickness of 30 mm installed horizontally on a concrete floor.
[operation]
1. 1. The cured coating film surface of the laminated film was turned upward and fixed on a steel table.
2. The weight was hung at a position where the distance from the surface of the laminated film to the lower end of the weight was 50 mm, and after confirming that the runout and rotation had stopped, the weight was dropped onto the laminated film.
3. 3. After the laminated film after the drop test was allowed to stand indoors for 1 hour, damage to the coated surface was examined.
4. The test was continued with a distance of 10 mm from the surface of the laminated film to the lower end of the weight, and the evaluation was made at the maximum distance at which the cured coating film did not crack or peel off.

Claims (6)

A urethane (meth) acrylate resin containing isophorone diisocyanate or a modified product (A) thereof and dipentaerythritol (meth) acrylate (B) as essential reaction raw materials.
The dipentaerythritol poly (meth) acrylate (B) is composed of dipentaerythritol tetra (meth) acrylate (b1), dipentaerythritol penta (meth) acrylate (b2) and dipentaerythritol hexa (meth) acrylate (b3). Contains,
The ratio of the contents of the dipentaerythritol tetra (meth) acrylate (b1) to the dipentaerythritol penta (meth) acrylate (b2) [(b1) / (b2)] is [7.2 × 100 / (7.2 + 48). .3)] / [48.3 × 100 / (7.2 + 48.3)] to [15 × 100 / (15 + 60)] / [60 × 100 / (15 + 60)] .
A urethane (meth) acrylate resin in which the content of the dipentaerythritol hexa (meth) acrylate (b3) is in the range of 5 to 30.7% by mass in the dipentaerythritol poly (meth) acrylate (B). The urethane (meth) acrylate resin according to claim 1, wherein the hydroxyl value of the dipentaerythritol (meth) acrylate (B) is in the range of 50 to 120 mgKOH / g. The urethane (meth) acrylate resin according to claim 1, wherein the content of dipentaerythritol tetra (meth) acrylate (b1) in the dipentaerythritol (meth) acrylate (B) is in the range of 1 to 30%. A curable composition containing the urethane (meth) acrylate resin according to any one of claims 1 to 3 and a photopolymerization initiator. A cured product of the curable composition according to claim 4. A laminated film having a layer made of the cured product according to claim 5 and another plastic film layer.