Photocurable resin composition

Abstract

The present invention relates to a photocurable resin composition and, more specifically, to a photocurable resin composition having improved mechanical properties due to photocuring being carried out comprising a photocurable monomer and urethane di(meth)acrylate prepared by imparting an acrylic group to a polyol having hydroxyl groups at both ends, so as to enable photopolymerization.

Description

Photocurable resin composition The present invention relates to a photocurable resin composition, and more specifically, to a photocurable resin composition having improved mechanical properties by photocuring, which comprises a urethane di(meth)acrylate prepared by imparting an acrylic group to a polyol having hydroxyl groups at both terminals so as to enable photopolymerization, and a photocurable monomer. Recently, the optical properties and thinness of optical materials applied to flat panel displays are becoming more important, and hybrid optical materials that combine various optical materials are being applied. Accordingly, adhesive sheets and glues using photocurable resins that can be cured by ultraviolet irradiation to bond optical materials are becoming more important. These photocurable resins are useful because they do not contain volatile components and can be cured in a short period of time. However, in the case of polyols that do not have a curing mechanism, they cannot be cured by the photocuring method, so there are limitations in applying mechanical properties such as elongation and tensile strength. In order to solve the above problems, the research team found that when urethane di(meth)acrylate is manufactured by imparting acrylic groups to enable photopolymerization of two or more polyols with high wear resistance and mechanical strength among various polyols that determine the elasticity and flexibility of the resin, it exhibits improved physical properties. Accordingly, the present invention aims to provide a photocurable resin composition comprising a photocurable urethane acrylate synthesized to have a photocurable reaction mechanism in a polyol. In order to solve the above problem, the photocurable resin composition according to the present invention (A) Urethane di(meth)acrylate obtained by subjecting a compound represented by the following chemical formula 1 or 2 to a urethane reaction with a (meth)acrylate containing isocyanate; (B) a photocurable monomer; and (C) a photopolymerization initiator; obtained by photocuring. [Chemical Formula 1] (n is 10 to 50) [Chemical formula 2] (m is 10 to 50) The above urethane di(meth)acrylate may be a compound represented by the following chemical formula 3 or chemical formula 4. [Chemical Formula 3] [Chemical Formula 4] In the above chemical formulas 3 and 4, R1 and R2 are each hydrogen or a methyl group, and n and m are each 10 to 50. The (meth)acrylate containing the above isocyanate may be 2-isocyanoethyl (meth)acrylate. The above photocurable monomer may be a (meth)acrylate monomer represented by the following chemical formula 5. [Chemical Formula 5] (R1 is C 2-20 is a linear or branched alkyl group, and R2 is hydrogen or a methyl group) The above photopolymerization initiator may be selected from at least one selected from the group consisting of triazine-based, acetophenone-based, benzophenone-based, thioxanthone-based, benzoin-based, phosphorus-based, oxime-based, and mixtures thereof. The photocurable resin composition according to the present invention can be formed by photocuring, comprising (A) 10 to 60 parts by weight of urethane di(meth)acrylate, (B) 40 to 90 parts by weight of a photocurable monomer, and (C) 0.1 to 3 parts by weight of a photopolymerization initiator. The above photocurable resin composition may further include at least one additive selected from the group consisting of a surfactant, a curing accelerator, and an antioxidant. Another invention relates to an optical film comprising the photocurable resin composition. The photocurable resin composition according to the present invention can have improved mechanical properties by being formed by photocuring a urethane di(meth)acrylate prepared by imparting an acrylic group to two or more polyols having high wear resistance and mechanical strength to enable photopolymerization. Hereinafter, the present invention will be described in detail. The term “(meth)acryl” as used herein means acryl and / or methacryl. The term “alkyl group” as used herein, unless otherwise stated, means a radical of a saturated aliphatic functional group having 1 to 60 carbon atoms linked by a single bond, including a linear alkyl group, a branched alkyl group, a cycloalkyl (alicyclic) group, an alkyl-substituted cycloalkyl group, and a cycloalkyl-substituted alkyl group. The photocurable resin composition according to the present invention comprises (A) a urethane di(meth)acrylate obtained by subjecting a compound represented by the following chemical formula 1 or 2 to a urethane reaction with a (meth)acrylate containing an isocyanate; (B) a photocurable monomer; and (C) a photopolymerization initiator; and is obtained by photocuring. [Chemical Formula 1] (n is 10 to 50) [Chemical formula 2] (m is 10 to 50) The above urethane di(meth)acrylate may be a compound represented by the following chemical formula 3 or chemical formula 4. [Chemical Formula 3] [Chemical Formula 4] In the above chemical formulas 3 and 4, R1 and R2 are hydrogen or methyl groups, respectively, and n and m are 10 to 50, respectively. The (meth)acrylate containing the above isocyanate may be, but is not necessarily limited to, 2-isocyanoethyl (meth)acrylate. In relation to the method for producing the above urethane di(meth)acrylate, the (meth)acrylate containing the above isocyanate is reacted with the compound represented by the above chemical formula 1 or chemical formula 2 at 60 to 80°C in the presence of a catalyst such as DBTDL to impart a photocurable acrylic group to the polyol. Thereafter, the hydroxyl groups at both ends of the polyol can react with the isocyanate to produce a synthetic product having a di(meth)acrylate polyurethane structure represented by the chemical formula 3 or 4. The above photocurable monomer may be a (meth)acrylate monomer represented by the following chemical formula 5. [Chemical Formula 5] (R1 is C 2-20 is a linear or branched alkyl group, and R2 is hydrogen or a methyl group) More specifically, the (meth)acrylate is selected from the group consisting of decyl (meth)acrylate, isodecyl (meth)acrylate, 4-methyl-2-propylhexyl (meth)acrylate, isobornyl (meth)acrylate, dodecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, octadecyl (meth)acrylate, isooctadecyl (meth)acrylate, 2-heptylundecyl (meth)acrylate, dicyclopentanyl (meth)acrylate, admentyl (meth)acrylate, admentylpropyl (meth)acrylate, ethyl admentyl (meth)acrylate, methyl admentyl (meth)acrylate, isobornyl (meth)acrylate, ethyltricyclodecyl (meth)acrylate, One or more may be selected from the group consisting of methyltricyclodecyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, and 2-phenylphenoxyethyl (meth)acrylate, but is not necessarily limited thereto. The photocurable resin composition according to the present invention includes a photopolymerization initiator capable of curing a photocurable monomer through UV irradiation or the like. The photopolymerization initiator is not particularly limited as long as it is a conventional photopolymerization initiator capable of performing a photocurable reaction. For example, the photopolymerization initiator may include a triazine type, an acetophenone type, a benzophenone type, a thioxanthone type, a benzoin type, a phosphorus type, an oxime type, or a mixture thereof. The above triazine series includes 2,4,6-trichloro-s-triazine, 2-phenyl-4,6-bis(trichloromethyl)-s-triazine, 2-(3',4'-dimethoxy styryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4'-methoxy naphthyl)-4,6-bis(trichloromethyl)-s-triazine, 2-(p-methoxy phenyl)-4,6-bis(trichloromethyl)-s-triazine, 2-(p-tolyl)-4,6-bis(trichloromethyl)-s-triazine, 2-biphenyl-4,6-bis(trichloromethyl)-s-triazine, bis(trichloromethyl)-6-styryl-s-triazine, 2-(naphtho-1-yl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4-methoxy naphtho-1-yl)-4,6-bis(trichloromethyl)-s-triazine, 2,4-trichloromethyl(piperonyl)-6-triazine, 2,4-(trichloromethyl(4'-methoxy styryl)-6-triazine or a mixture thereof. The above acetophenones include 2,2'-diethoxy acetophenone, 2,2'-dibuthoxy acetophenone, and 2-

[0230] Hydroxy-2-methylpropiophenone, pt-butyl trichloro acetophenone, pt-butyl dichloro acetophenone, 4-chloro

[0231] Acetophenone, 2,2'-dichloro-4-phenoxy acetophenone, 2-methyl-1-(4-(methylthio)phenyl)-2-morpholino propan-1-one, 2-benzyl-2-dimethyl amino-1-(4-morpholino phenyl)-butan-1-one, or a mixture thereof. The above benzophenone series may be benzophenone, benzoyl benzoate, methyl benzoyl benzoate, 4-phenyl benzophenone, hydroxy benzophenone, acrylated benzophenone, 4,4'-bis(dimethylamino)benzophenone, 4,4'-dichloro benzophenone, 3,3'-dimethyl-2-methoxy benzophenone, or a mixture thereof. The above thioxanthone series may be thioxanthone, 2-methyl thioxanthone, isopropyl thioxanthone, 2,4-diethyl thioxanthone, 2,4-diisopropyl thioxanthone, 2-chloro thioxanthone or a mixture thereof. The above benzoin group may be benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzyl dimethyl ketal or a mixture thereof. The above mentioned catalyst may be bisbenzoylphenyl phosphine oxide, benzoyldiphenyl phosphine oxide or a mixture thereof. The above oximes may be 2-(o-benzoyloxime)-1-[4-(phenylthio)phenyl]-1,2-octanedione and 1-(o-acetyloxime)-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone, or a mixture thereof. The photocurable resin composition according to the present invention may be formed by including 10 to 60 parts by weight of urethane di(meth)acrylate, 40 to 90 parts by weight of a photocurable monomer, and 0.1 to 3 parts by weight of a photopolymerization initiator, based on 100 parts by weight of the total composition. This is because the physical properties are exhibited and commercially available within the content range of the urethane di(meth)acrylate based on 100 parts by weight of the entire composition, and Tg and viscosity can be adjusted within the content range of the total photocurable monomer. In addition, not only can photopolymerization sufficiently occur upon exposure within the content range of the photopolymerization initiator, but also outgassing and reliability deterioration due to unreacted initiator remaining after photopolymerization can be prevented. The photocurable resin composition according to the present invention may additionally include at least one additive selected from the group consisting of a surfactant, a curing accelerator, and an antioxidant. In particular, the surfactant is advantageous in inducing dispersion of the composition. Another invention may relate to an optical film comprising the photocurable resin composition. The optical film may include a coating layer of the photocurable resin composition on at least one side of a substrate. The substrate is not particularly limited as long as it can be used as a substrate of an optical film. For example, the substrate may be a polyethylene terephthalate film, a polycarbonate film, a polypropylene film, a polyethylene film, a polystyrene film, or a polyepoxy film. The coating layer of the above photocurable resin composition can be appropriately adjusted depending on its use, and for example, when applied to the field of transparent displays, it can be 50 to 100 nm. Hereinafter, the present invention will be specifically described by way of examples of a photocurable resin composition according to the present invention, but the present invention is not limited to the following examples. [Example] Photocurable resin compositions of Examples 1 and 2 and Comparative Examples 1 and 2 were prepared by mixing monomers, photopolymerization initiators (BAPO), and surfactants according to Table 1 below, and their mechanical strengths were measured. Monomer (weight parts) Photopolymerization initiator (weight parts) Modulus (MPa) TDMA2-EHAPUDA Polyester polyol BAPO Example 143.92-0.143221.96-0.1121 Comparative example 154.9--0.12243.9-20.126 - TDMA: Tetramethylene dimethacrylate- 2-EHA: 2-Ethylhexyl acrylate - BAPO: bisacylphosphine oxide - PUDA: Polyurethane diacrylate with a water content of 3000 represented by chemical formula 3 - Polyester polyol: Polyester polyol with a water content of 3000 As a result of the measurement, the mechanical strength of Examples 1 and 2 manufactured using polyurethane acrylate according to the present invention was significantly superior to that of Comparative Examples 1 and 2. This is because the photocurable resin composition according to the present invention has the mechanical properties of polyol. The above description is merely an example of the present invention, and those skilled in the art will appreciate that various modifications may be made without departing from the essential characteristics of the present invention. Accordingly, the embodiments disclosed in this specification are not intended to limit the present invention but to explain it, and the spirit and scope of the present invention are not limited by these embodiments. The scope of protection of the present invention should be interpreted by the following claims, and all techniques within a scope equivalent thereto should be interpreted as being included in the scope of the rights of the present invention.

Claims

1. (A) Urethane di(meth)acrylate obtained by reacting a compound represented by the following chemical formula 1 or 2 with a (meth)acrylate containing isocyanate; (B) a photocurable monomer; and (C) Photopolymerization initiator; A photocurable resin composition obtained by photocuring, including: [Chemical Formula 1] (n is 10 to 50) [Chemical formula 2] (m is 10 to 50) 2. In paragraph 1, The above urethane di(meth)acrylate is a photocurable resin composition, which is a compound represented by the following chemical formula 3 or chemical formula 4: [Chemical Formula 3] [Chemical Formula 4] In the above chemical formulas 3 and 4, R1 and R2 are hydrogen or methyl groups, respectively, and n and m are 10 to 50, respectively.

3. In paragraph 1, A photocurable resin composition, wherein the (meth)acrylate containing the above isocyanate is 2-isocyanoethyl (meth)acrylate.

4. In paragraph 1, A photocurable resin composition, wherein the photocurable monomer is a (meth)acrylate monomer represented by the following chemical formula 5. [Chemical Formula 5] (R1 is C 2-20 is a linear or branched alkyl group, and R2 is hydrogen or a methyl group) 5. In paragraph 1, A photocurable resin composition, wherein the photopolymerization initiator is at least one selected from the group consisting of triazine-based, acetophenone-based, benzophenone-based, thioxanthone-based, benzoin-based, phosphorus-based, oxime-based, and mixtures thereof.

6. In paragraph 1, Based on 100 parts by weight of the total composition, A photocurable resin composition comprising (A) 10 to 60 parts by weight of urethane di(meth)acrylate, (B) 40 to 90 parts by weight of a photocurable monomer, and (C) 0.5 to 3 parts by weight of a photopolymerization initiator.

7. In paragraph 1, A photocurable resin composition further comprising at least one additive selected from the group consisting of a surfactant, a curing accelerator, and an antioxidant.

8. An optical film comprising a photocurable resin composition according to any one of claims 1 to 7.

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