Curable resin composition for decorative films and decorative film

Abstract

To provide a curable resin composition for decorative films that offers high flexibility while also yielding a cured product with excellent surface hardness, scratch resistance, and chemical resistance. [Solution] A curable resin composition for decorative films comprising (a) a urethane (meth)acrylate having 2 to 9 unsaturated bonds, and (b) a photopolymerization initiator, wherein the (b) photopolymerization initiator comprises (b-1) a triazine peroxide derivative represented by general formula (1), and the (b-1) component is 0.01 to 15 parts by mass per 100 parts by mass of the (a) component.

Description

[Technical Field]

[0001] The present invention relates to a curable resin composition for decorative films and a decorative film. [Background technology]

[0002] Conventionally, methods have been used to apply a hard coat layer to the surface of molded plastics and other materials by coating them with photocurable or thermosetting resins to provide aesthetic appeal, surface hardness, scratch resistance, or chemical resistance for surface protection. However, these methods require molding of the product by injection molding, coating of the resin composition, drying, and curing, resulting in lengthy processes, low productivity, and difficulty in uniformly forming a hard coat layer on molded products with complex shapes.

[0003] On the other hand, recently, molding methods that use decorative films having a printed layer and a hard coat layer to add design elements to the surface of complexly shaped plastic molded products have been attracting attention. A typical molding method using decorative films is film insert molding, in which the decorative film is inserted into the mold during injection molding, and the decorative film and the molded product are molded as one unit. This method is used for molding exterior components with complex shapes in fields such as mobile phones, personal computers, home appliances, and automotive parts. Therefore, the hard coat layer of the decorative film is required to have excellent hard coat properties such as surface hardness, scratch resistance, and chemical resistance (sunscreen resistance, etc.), as well as flexibility to conform to complex shapes.

[0004] Under these circumstances, UV-curable coating compositions have been proposed that can form coating films for decorative films with moldability applicable to molding methods such as film insert molding and in-mold molding. For example, a method for manufacturing injection-molded articles has been proposed that uses a film laminate having a semi-cured resin layer obtained by semi-curing a cationic UV-curable coating composition, and that utilizes a semi-cured film laminate with high surface hardness and excellent adhesion and conformability to resin molded products with three-dimensional curved shapes (Patent Document 1). [Prior art documents]

Patent Document

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, the method proposed in Patent Document 1 is difficult to stably manufacture molded products when molding at high temperatures, and since the semi-cured resin layer is cation-curable, it is necessary to heat for a long time. Therefore, it cannot be said that it is a suitable method from the viewpoint of production efficiency. Therefore, it is preferable to use a film laminate in which the cured resin layer is completely cured by ultraviolet curing, but there is a risk that the coating film may crack because it cannot follow a complex shape.

[0007] Also, generally, flexibility and hard coat properties such as surface hardness are mutually contradictory characteristics. In this regard, although a certain degree of flexibility can be obtained in the conventional curable resin composition, it cannot be said that the hardness, chemical resistance, etc. are still sufficient, and further improvement is required.

[0008] Therefore, an object of the present invention is to provide a curable resin composition for a decorative film that has high flexibility and can obtain a cured product excellent in surface hardness, scratch resistance, and chemical resistance.

Means for Solving the Problems

[0009] That is, the present invention is a curable resin composition for a decorative film containing (a) urethane (meth) acrylate having 2 to 9 unsaturated bonds, and (b) a photopolymerization initiator, and the (b) photopolymerization initiator is (b-1) General formula (1):

Chemical formula

[0010] Furthermore, the present invention relates to a decorative film using the curable resin composition for a decorative film. [Advantages of the Invention]

[0011] The curable resin composition for decorative films of the present invention yields a cured product that possesses high flexibility while also exhibiting excellent surface hardness, scratch resistance, and chemical resistance. [Modes for carrying out the invention]

[0012] <Curable resin composition for decorative films> The curable resin composition for decorative films of the present invention (hereinafter also simply referred to as "curable resin composition") comprises (a) a urethane (meth)acrylate having 2 to 9 unsaturated bonds, and (b) a photopolymerization initiator.

[0013] <(a) Urethane (meth)acrylate having 2 to 9 unsaturated bonds> The present invention's (a) urethane (meth)acrylate having 2 to 9 unsaturated bonds (hereinafter also simply referred to as "urethane (meth)acrylate" or "component (a)") is a compound having urethane bonds and two or more radical polymerizable functional groups, such as ethylenically unsaturated groups, within its molecule. Urethane acrylate can be obtained, for example, by reacting a polyhydric alcohol with a polyisocyanate such as isocyanate or isocyanurate and a monofunctional (meth)acrylic monomer having a hydroxyl group. Component (a) may be used alone or in combination of two or more types.

[0014] Examples of polyhydric alcohols used as raw materials for urethane acrylates include 1,3-butanediol, 1,4-butanediol, trimethylolethane, trimethylolpropane, ditrimethylolethane, ditrimethylolpropane, pentaerythritol, dipentaerythritol, tripentaerythritol, diglycerol, glycerin, and numerous other diols such as polysiloxane polyols, poly(oxyalkylene) polyols, polyester polyols, polyether polyols, polyether polyester polyols, polyolefin polyols, poly(alkyl acrylate) polyols, and polycarbonate polyols.

[0015] Examples of isocyanates or polyisocyanates used as raw materials for urethane acrylates include tetramethylene diisocyanate, hexamethylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, 3,3-dimethyl-4,4-diphenylene isocyanate, isophorone diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, 1,3-bis(isocyanate methyl)cyclohexane, 1,3-bis(α,α-dimethylisocyanate methyl)benzene, trimethylhexamethylene diisocyanate, and hydrogenated xylylene diisocyanate.

[0016] Examples of monofunctional (meth)acrylic monomers having hydroxyl groups that can be used as raw materials for urethane acrylates include trimethylolpropane diacrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxycyclohexyl (meth)acrylate, 5-hydroxycyclooctyl (meth)acrylate, 2-hydroxy-3-phenyloxypropyl (meth)acrylate, pentaerythritol triacrylate, dipentaerythritol pentaacrylate, and oxyethyl di(meth)acrylate isocyanurate.

[0017] (a) The number of unsaturated bonds (functional groups) in component (a) is preferably 2 to 7, and more preferably 2 to 5. If the number of unsaturated bonds (functional groups) exceeds 9, the flexibility of the cured film decreases.

[0018] (a) The molecular weight of component (a) is preferably in the range of 1,000 to 100,000 in terms of number average molecular weight, and more preferably in the range of 3,000 to 50,000. If the number average molecular weight is 1,000 or more, the flexibility of the resulting cured film will be high, while if the number average molecular weight is 100,000 or less, the viscosity of the resin composition will be suppressed, resulting in excellent compatibility with other materials and excellent coatability. <(b) Photopolymerization initiator> The (b) photopolymerization initiator of the present invention comprises a triazine peroxide derivative represented by the following general formula (1) (hereinafter also simply referred to as "component (b-1)"). [ka] ((In general formula (1), R 1 and R 2 R is independently a methyl group or an ethyl group. 3 R represents an aliphatic hydrocarbon group having 1 to 5 carbon atoms, or an aromatic hydrocarbon group having 6 to 9 carbon atoms which may have an alkyl group. 4 R is an optionally substituted C1-C20 aliphatic hydrocarbon group, an optionally substituted C6-C20 aromatic hydrocarbon group, an optionally substituted C2-C20 heterocyclic group, an optionally substituted C1-C20 acyl group, -YR, or -N-RR', where Y represents an oxygen atom or a sulfur atom, and R and R' independently represent a hydrogen atom, an optionally substituted C1-C20 aliphatic hydrocarbon group, an optionally substituted C6-C20 aromatic hydrocarbon group, or an optionally substituted C2-C20 heterocyclic group. Ar is represented by the following general formula (2):Ar 1 Ar 2 Ar 3 This is an aryl group represented by [this symbol]. [ka] (In general formula (2), n represents an integer from 0 to 3. R 5 R is an independent substituent, an alkyl group having 1 to 18 carbon atoms, general formula (3):R 6 -Y- represents a substituent, nitro group, or cyano group. The Y represents an oxygen atom or a sulfur atom. The R represents 6 R represents a C1 to C18 hydrocarbon group which may have one or more ether bonds, thioether bonds, and terminal hydroxyl groups in its carbon skeleton, a C6 to C9 aromatic hydrocarbon group which may have an alkyl group, or a C1 to C8 acyl group. Alternatively, R 5 The two adjacent general formulas (3):R 6-Y- may form a 5-6 membered ring.

[0019] In general formula (1), R 1 and R 2 This group independently represents either a methyl group or an ethyl group, and a methyl group is preferred from the viewpoint of increasing the stability of the triazine peroxide derivative.

[0020] In general formula (1), R 3 R represents an aliphatic hydrocarbon group having 1 to 5 carbon atoms, or an aromatic hydrocarbon group having 6 to 9 carbon atoms, which may have an alkyl group. The alkyl group may be linear or branched. 3 Specific examples include methyl groups, ethyl groups, propyl groups, 2,2-dimethylpropyl groups, phenyl groups, and isopropylphenyl groups. Among these, methyl groups, ethyl groups, propyl groups, 2,2-dimethylpropyl groups, and phenyl groups are preferred from the viewpoint of facilitating the synthesis of triazine peroxide derivatives. Methyl groups and ethyl groups are more preferred from the viewpoint of increasing the stability of the triazine peroxide derivative and efficiently absorbing light.

[0021] In general formula (1), R 4 R is an optionally substituted C1-C20 aliphatic hydrocarbon group, an optionally substituted C6-C20 aromatic hydrocarbon group, an optionally substituted C2-C20 heterocyclic group, an optionally substituted C1-C20 acyl group, -YR, or -N-RR', where Y represents an oxygen atom or a sulfur atom, and R and R' independently represent a hydrogen atom, an optionally substituted C1-C20 aliphatic hydrocarbon group, an optionally substituted C6-C20 aromatic hydrocarbon group, or an optionally substituted C2-C20 heterocyclic group. 4 Because the effect of triazine peroxide derivatives on the absorption wavelength is small, R 4Even within the above wide range, good sensitivity is exhibited. Furthermore, the "substituents" in "may be substituted" above include halogen atoms, aliphatic hydrocarbon groups which may have ether or thioether bonds in the carbon skeleton, aromatic hydrocarbon groups, heterocyclic groups, acyl groups, cyano groups, nitro groups, carboxyl groups, epoxy groups, hydroxyl groups, etc. Above R 4 From the viewpoint of high storage stability of the polymerizable composition, R is preferably a C1-C20 aliphatic hydrocarbon group which may be substituted, a C6-C20 aromatic hydrocarbon group which may be substituted, a C2-C20 heterocyclic group which may be substituted, a C1-C20 acyl group which may be substituted, or -YR. From the viewpoint of ease of synthesis, R is more preferably -OR, where R is a C1-C20 aliphatic hydrocarbon group which may be substituted, a C6-C20 aromatic hydrocarbon group which may be substituted, or a C2-C20 heterocyclic group which may be substituted.

[0022] In general formula (2), n represents an integer from 0 to 3. From the viewpoint of ease of composition, it is preferable that n be between 0 and 2, and from the viewpoint of efficient light absorption, it is more preferable that n be 1.

[0023] In general formula (2), R 5 R is an independent substituent, an alkyl group having 1 to 18 carbon atoms, general formula (3):R 6 -Y- represents a substituent, nitro group, or cyano group. Y represents an oxygen atom or a sulfur atom. 6 R represents a C1 to C18 hydrocarbon group which may have one or more ether bonds, thioether bonds, and terminal hydroxyl groups in its carbon skeleton, a C6 to C9 aromatic hydrocarbon group which may have an alkyl group, or a C1 to C8 acyl group. Alternatively, R 5 These are two adjacent general formulas (3): R 6 -Y- may form a 5-6 membered ring.

[0024] R 5From the viewpoint of efficiently absorbing active energy rays, the substituent is an independent alkyl group having 1 to 6 carbon atoms, or general formula (4):R 6´ -Y- represents a substitution, where Y represents an oxygen atom, and R 6´ It is preferable that the carbon skeleton contains one or more ether bonds and / or hydroxyl groups at its terminus, or one or more aromatic hydrocarbon groups containing 6 to 9 carbon atoms, or an alkyl group. Alternatively, R 5 These are two adjacent general formulas (4)R 6´ It is preferable to form a 5-6 membered ring with -Y-.

[0025] R 5 Specific examples include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, and n-hexyl groups; methoxy, ethoxy, n-propyloxy, isopropyloxy, n-butyloxy, sec-butyloxy, tert-butyloxy, n-pentyloxy, cyclopentyloxy, n-hexyloxy, cyclohexyloxy, 2-hydroxyethoxy, 2-methoxyethoxy, 2-ethoxyethoxy, 2-butoxyethoxy, 2-(2-hydroxyethoxy)ethoxy, 2-(2-ethoxyethoxy)ethoxy, 1,2-dihydroxypropoxy, and methylenedioxy. Examples of functional groups include alkoxy groups such as oxy groups, dimethylmethylenedioxy groups, and ethylenedioxy groups; aryloxy groups such as phenyloxy groups and 4-isopropylphenyloxy groups; alkylsulfanil groups such as methylsulfanil groups, ethylsulfanil groups, hexylsulfanil groups, 2-methoxyethylsulfanil groups, and 2-(2-methoxyethoxy)ethylsulfanil groups; arylsulfanil groups such as phenylsulfanil groups, 2-methylphenylsulfanil groups, and 4-methylphenylsulfanil groups; and acyl groups such as acetyl groups, n-butanoyl groups, 2-ethylhexanoyl groups, benzoyl groups, and 2-methylbenzoyl groups. Compounds represented by general formula (3) having these functional groups are preferred because they efficiently absorb light.

[0026] Furthermore, among these, triazine peroxide derivatives are easy to synthesize and, from the viewpoint of efficiently absorbing light, R 5 A methoxy group, an ethoxy group, or a 2-hydroxyethoxy group is more preferred.

[0027] R 5 The substitution position is not particularly limited, but X is Ar 1 In the case of R 5 Preferably, at least one of the triazine groups is substituted at the 4-position of the benzene ring. Also, X is Ar 2 In the case of R 5 Preferably, at least one of the triazine groups is substituted at the 4-position of a benzene ring other than the benzene ring substituted with the triazine group. Also, X is Ar 3 In the case of R 5 From the viewpoint of efficiently absorbing light, it is preferable that at least one of the triazine groups is substituted at the 4-position of the triazine group substituted at the 1-position.

[0028] The amount of component (b-1) is 0.01 to 15 parts by mass per 100 parts by mass of component (a). From the viewpoint of curability and chemical resistance, the amount of component (b-1) is preferably 0.1 parts by mass or more, and more preferably 0.5 parts by mass or more, per 100 parts by mass of component (a), and from the viewpoint of flexibility, it is preferably 12 parts by mass or less, and more preferably 10 parts by mass or less, per 100 parts by mass of component (a). Component (b-1) may be used alone or in combination of two or more types.

[0029] Furthermore, in the present invention, by using other polymerization initiators in addition to component (b-1) as photopolymerization initiators, the surface curability, deep curability, etc., of the curable resin composition can be improved. When selecting other polymerization initiators, the type of additives, the thickness of the cured film, etc., should be considered, as should be considered, such as (a) urethane (meth)acrylate having 2 to 9 unsaturated bonds.

[0030] Other known polymerization initiators can be used. For example, α-hydroxyacetophenone derivatives such as 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methylpropiophenone, 4'-(2-hydroxyethoxy)-2-hydroxy-2-methylpropiophenone, 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)-2-methylpropan-1-one; 2-methyl-4'-methylthio-2-morpholinopropiophenone, 2-benzyl-2-(N,N-dimethylamino)-1-(4-morpholino Alpha-aminoacetophenone derivatives such as phenyl)butan-1-one and 2-(dimethylamino)-2-(4-methylbenzyl)-1-(4-morpholinophenyl)butan-1-one; acylphosphine oxide derivatives such as diphenyl-2,4,6-trimethylbenzoylphosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, and ethyl(mesitylcarbonyl)phenylphosphineate; 1-[4-(phenylthio)phenyl]octane-1,2-dione-2-(O-benzoyloxy Oxime ester derivatives such as 1-[({1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]ethylidene}amino)oxy]ethanone; halomethyltriazine derivatives such as 2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(3,4-dimethoxystyryl)-4,6-bis(trichloromethyl)1,3,5-triazine, and 2-(4-ethoxynaphthyl)-4,6-bis(trichloromethyl)-1,3,5-triazine; 2,2-dimethyl Benzyl ketal derivatives such as toxic-2-phenylacetophenone; thioxanthone derivatives such as isopropylthioxanthone; benzophenone derivatives such as 4-(4-methylphenylthio)benzophenone; coumarin derivatives such as 3-benzoyl-7-diethylaminocoumarin and 3,3'-carbonylbis(7-diethylaminocoumarin); imidazole derivatives such as 2-(2-chlorophenyl)-1-[2-(2-chlorophenyl)-4,5-diphenyl-1,3-diazole-2-yl]-4,5-diphenylimidazole;Examples include organic peroxides such as 3,3',4,4'-tetrakis(tert-butylperoxycarbonyl)benzophenone and dibenzoyl peroxide; azo compounds such as azobisisobutyronitrile; and camphorquinone. Other polymerization initiators may be used alone or in combination of two or more.

[0031] <(c) Solvent> To improve viscosity, coatability, and the smoothness of the cured film, the curable resin composition may further contain (c) a solvent (hereinafter also simply referred to as "component (c)").

[0032] (c) Examples of solvents include acetone, methyl ethyl ketone, toluene, xylene, methyl isobutyl ketone, ethyl acetate, ethylene glycol monomethyl ether, N,N-dimethylformamide, N,N-dimethylacetamide, methanol, ethanol, etc. (c) The solvent may be used alone or in combination of two or more types.

[0033] (c) The solvent can be used to adjust the viscosity when forming a coating film of the curable resin composition of the present invention. From the viewpoint of coatability and transparency of the coating film, the solid content concentration of the curable resin composition is preferably 5 to 90% by mass, and more preferably 10 to 80% by mass.

[0034] <Other hardening components> The curable resin composition may further contain curable components having ethylenically unsaturated double bonds, such as (meth)acrylate polymers, (meth)acrylate oligomers, and (meth)acrylate monomers, which have different numbers of functional groups and structures other than urethane (meth)acrylate having 2 to 9 unsaturated bonds. Examples of such curable components include acrylic (meth)acrylate, polyester (meth)acrylate oligomer, epoxy (meth)acrylate oligomer, and (meth)acrylate monomer.

[0035] <Filler> The curable resin composition may further contain fillers. By including fillers, the physical properties of the cured film, such as scratch resistance, can be improved. Examples of fillers include fine particles such as alumina and nanosilica. Among these, the use of alumina fine particles is preferred.

[0036] The average primary particle size of the filler is preferably 1 to 100 nm, and more preferably 50 nm or less, from the viewpoint of dispersibility and transparency.

[0037] <Other additives, etc.> The curable resin composition may optionally contain known additives such as sensitizers, thermosetting agents, crosslinking agents, crosslinking accelerators, silane coupling agents, tackifying resins (rosin derivatives, polyterpene resins, petroleum resins, oil-soluble phenols, etc.), antioxidants, fillers, colorants (pigments, dyes, etc.), UV absorbers, antioxidants, chain transfer agents, plasticizers, softeners, surfactants, antistatic agents, thickeners, flame retardants, inorganic compounds, and electromagnetic wave absorbing fillers, either individually or in combination of two or more, as long as they do not impair the properties of this embodiment.

[0038] <Method for preparing a curable resin composition> The method for preparing the curable resin composition is not particularly limited. The above components may be mixed in predetermined proportions and then mixed according to conventional methods using a paint shaker, bead mill, sand grind mill, ball mill, attritor mill, two-roll mill, three-roll mill, etc.

[0039] <Decorative film> The decorative film of the present invention is obtained using a curable resin composition. The decorative film may be, for example, a decorative film in which a curable resin composition is laminated on a base film, or it may be a decorative film consisting of a curable resin composition alone.

[0040] The coating method for the curable resin composition can be any known coating method, and the curing method for the curable resin composition can be selected according to the production process, such as a pre-cure method where it is cured before decorative molding, an after-cure method where it is cured after decorative molding, or a semi-curing method where it is in a semi-cured state before decorative molding and fully cured after decorative molding. Examples of decorative molding for decorative films include primary decoration such as in-mold molding and sheet molding, and secondary decoration such as film lamination / transfer, printing, and vacuum deposition.

[0041] The thickness of the cured film formed from the curable resin composition is preferably in the range of 0.1 μm to 250 μm, more preferably 0.5 μm to 100 μm, and particularly preferably 1 μm to 50 μm. When the film thickness is within the above range, the film strength is good, and the surface hardness, scratch resistance, and chemical resistance of the cured film are also good.

[0042] The method for curing the curable resin composition is not particularly limited, but it is preferable to cure it by irradiation with active energy rays such as electron beams, ultraviolet rays, visible light, or radiation. The exposure amount of the active energy rays can be appropriately set according to the wavelength and intensity of the active energy rays, the composition of the curable resin composition, and the film thickness. As an example, the exposure amount in the UV-A region is 10 to 5,000 mJ / cm². 2 Preferably, the concentration is 50-3,000 mJ / cm². 2 It is more preferable that this is the case. In addition, a heating step may be performed before or after the step of irradiation with active energy rays.

[0043] Furthermore, because the curable resin composition of the present invention has flexibility and hard coating properties in its cured film, it is also useful for applications such as hard coating films for optical lenses (prism sheets, collimator lenses, Fresnel lenses, lenticular lenses, back-reflecting lenses, holograms, etc.), anti-reflective films, and decorative sheets (interior materials for floors, walls, ceilings, etc. of buildings). [Examples]

[0044] The present invention will be described in more detail below with reference to examples. The present invention is not limited to these examples.

[0045] <Preparation of a curable resin composition for decorative films> Each component was mixed in the proportions shown in Table 1 to obtain the curable resin compositions of Examples 1-9 and Comparative Examples 1-3. These curable resin compositions were evaluated according to the following method.

[0046] [Evaluation Method] (curable) The curable resin composition obtained above was coated onto an easily adhesive treated PET film (Cosmoshine A4300, manufactured by Toyobo) using a bar coater to create a uniform coating film with a thickness of approximately 30 μm. Next, an illuminance of 4.0 W / cm² was applied using a 385 nm LED light source. 2 Light irradiation was performed at a line speed of 6 m / min. The cured surface was palpated, and the number of irradiations required until the curable resin composition no longer stuck to the hand was evaluated as curability.

[0047] (Flexibility) The curable resin composition prepared above was injected into a glass plate with a 0.5 mm thick spacer in between, and an illuminance of 4.0 W / cm² was applied using a 385 nm LED light source. 2 A cured film was obtained by light irradiation under the conditions of a line speed of 6 m / min and 3 irradiation cycles. The obtained cured film was wrapped around SUS rods with diameters of 10 mm and 15 mm, and the change in appearance was evaluated visually according to the following criteria. An evaluation of ◎ or ○ is considered a pass, with ◎ being more preferable. ◎: No cracks were found in the hardened film wrapped around 10mm and 15mm diameter stainless steel rods. ○: Cracks were observed in the hardened film wrapped around a 10mm diameter stainless steel rod, but no cracks were found in the hardened film wrapped around a 15mm diameter stainless steel rod. ×: Cracks were found in the hardened film wrapped around SUS rods with diameters of 10 mm and 15 mm.

[0048] (Surface hardness (pencil hardness)) The curable resin composition obtained above was coated onto an easily adhesive treated PET film (Cosmoshine A4300, manufactured by Toyobo) using a bar coater to create a uniform coating film with a thickness of approximately 30 μm. Next, an illuminance of 4.0 W / cm² was applied using a 385 nm LED light source. 2 A cured film was obtained by light irradiation under the conditions of a line speed of 6 m / min and 3 irradiations. In accordance with JIS K5600, the hardest pencil that did not leave a scratch was used to determine the pencil hardness when a pencil was scratched approximately 10 mm while applying a load of 750 g at a 45° angle to the prepared cured film. The evaluation criteria for pencil hardness are as follows: An evaluation of ◎ or ○ is considered a pass, with ◎ being more preferable. ◎: The pencil has a hardness of 2H or higher. ○: The pencil has a hardness of H. ×: The pencil hardness is less than H.

[0049] (Chemical resistance) The curable resin composition obtained above was coated onto an easily adhesive treated PET film (Cosmoshine A4300, manufactured by Toyobo) using a bar coater to create a uniform coating film with a thickness of approximately 30 μm. Next, an illuminance of 4.0 W / cm² was applied using a 385 nm LED light source. 2 A cured film was obtained by light irradiation under the conditions of a line speed of 6 m / min and 3 irradiations. A commercially available sunscreen cream (product name "Neutrogena," manufactured by Johnson & Johnson, SPF 100) was applied to the surface of the prepared cured film, and after standing at a temperature of 80°C for 180 minutes, the degree to which the surface of the cured film changed from transparent to white after wiping off the sunscreen cream with a dry cloth was visually confirmed. The evaluation criteria for chemical resistance are as follows. An evaluation of ◎ or ○ is considered a pass, with ◎ being more preferable. ◎: The coating is transparent and no changes are observed. ○: Slight whitening is observed in some areas. ×: Whitening was observed in part or throughout the plant.

[0050] (Scratch resistance) The curable resin composition obtained above was coated onto an easily adhesive treated PET film (Cosmoshine A4300, manufactured by Toyobo) using a bar coater to create a uniform coating film with a thickness of approximately 30 μm. Next, an illuminance of 4.0 W / cm² was applied using a 385 nm LED light source. 2 A cured film was obtained by light irradiation under the conditions of a line speed of 6 m / min and 3 irradiation cycles. The prepared cured film was subjected to 10 passes of #0000 steel wool with a load of 200 g, and the surface of the cured film was observed visually. The evaluation criteria for scratch resistance are as follows. An evaluation of ◎ or ○ is considered a pass, with ◎ being more preferable. ◎: No peeling or damage to the membrane was observed. ○: A small, fine scratch is visible on a part of the membrane. ×: Muscle-like damage is observed throughout the membrane, or delamination of the membrane occurs.

[0051] Further details regarding the abbreviations and other terms listed in Table 1 are as follows: UV-7000B: 2-3 functional urethane (meth)acrylate (manufactured by Mitsubishi Chemical) UV-3700B: Bifunctional urethane (meth)acrylate (manufactured by Mitsubishi Chemical) M-306: Pentaerythritol tritetraacrylate (manufactured by Toagosei Co., Ltd.) TPO: Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (manufactured by IGM Resins BV) MEK: Methyl ethyl ketone

[0052] Compounds 1-6, listed in Table 1, were synthesized according to the method described in International Publication No. 2023 / 054225. Details of compounds 1-6 are shown in Table 2.

[0053] [Table 1]

[0054] [Table 2]

[0055] As shown in Table 1, the curable resin compositions of each example exhibited good curability, chemical resistance, surface hardness, scratch resistance, and excellent flexibility. On the other hand, the compositions of each comparative example showed insufficient curability or inferior flexibility and chemical resistance.

Claims

1. (a) A curable resin composition for decorative films comprising a urethane (meth)acrylate having 2 to 9 unsaturated bonds, and (b) a photopolymerization initiator. The photopolymerization initiator (b) is (b-1) General formula (1): 【Chemistry 1】 ((In general formula (1), R １ and R ２ R is independently a methyl group or an ethyl group. ３ R represents an aliphatic hydrocarbon group having 1 to 5 carbon atoms, or an aromatic hydrocarbon group having 6 to 9 carbon atoms which may have an alkyl group. ４ R is an optionally substituted C1-C20 aliphatic hydrocarbon group, an optionally substituted C6-C20 aromatic hydrocarbon group, an optionally substituted C2-C20 heterocyclic group, an optionally substituted C1-C20 acyl group, -Y-R, or -N-RR', where Y represents an oxygen atom or a sulfur atom, and R and R' independently represent a hydrogen atom, an optionally substituted C1-C20 aliphatic hydrocarbon group, an optionally substituted C6-C20 aromatic hydrocarbon group, or an optionally substituted C2-C20 heterocyclic group. Ar is represented by the following general formula (2): Ar １ Ar ２ , or Ar ３ (This is an aryl group represented by [this symbol].) 【Chemistry 2】 (In general formula (2), n represents an integer from 0 to 3, and R ５ is an independent substituent, an alkyl group having 1 to 18 carbon atoms, a substituent represented by general formula (3): R ６ -Y-, a nitro group, or a cyano group. The Y represents an oxygen atom or a sulfur atom. The R ６ has, in its carbon skeleton, an ether bond, a thioether bond, and / or a hydrocarbon group having 1 to 18 carbon atoms which may have at least one hydroxyl group at the terminal, an aromatic hydrocarbon group having 6 to 9 carbon atoms which may have an alkyl group, or an acyl group having 1 to 8 carbon atoms. Alternatively, R ５ may form a 5- to 6-membered ring with two adjacent general formulas (3): R ６ -Y-.)) and includes a triazine peroxide derivative represented by The curable resin composition for decorative films is characterized in that the (b-1) component is 0.01 to 15 parts by mass with respect to 100 parts by mass of the (a) component.

2. A decorative film using the curable resin composition for decorative films described in claim 1.

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