Curable resin composition for decorative film, decorative film, and decorative film molded article

Abstract

The present invention relates to a curable resin composition for a decorative film, a decorative film, and a decorative film molded product. The present invention provides a curable resin composition for a decorative film, comprising: a (meth)acrylic resin; a reactive (meth)acrylate composition; a first initiator; and a second initiator. The first initiator is a photopolymerization initiator and the second initiator is a peroxide, an azo compound, or a combination thereof. The second initiator is used in an amount of between 3 and 23 parts by weight per 100 parts by weight of the reactive (meth)acrylate composition, and the ratio of the amount of the first initiator to the amount of the second initiator is between 1:0.5 and 1:5. The curable resin composition for a decorative film of the present invention has good moldability, and the decorative film molded product formed after curing and molding can have appropriate hardness and excellent chemical resistance.

Description

Technical Field

[0001] This invention relates to a curable resin composition for decorative films, and more particularly to a curable resin composition with good formability, wherein the decorative molded article formed after curing has appropriate hardness and excellent chemical resistance. Background Technology

[0002] In recent years, there has been a demand for plastic extruded products such as mobile phone bodies, computer casings, and automotive interior panels that combine complex designs with durability. Therefore, decorative films can showcase more complex shapes and patterns compared to flat processing methods such as spray coating or printing. The molding process for decorative films is mainly divided into in-mold molding (IMD) and out-of-mold molding (OMD). The main steps of these processes include: heating and softening the resin, pressurizing the chamber, vacuuming, molding, and trimming. These molding technologies use formable substrates such as PMMA, ABS, or PETG; however, the surface properties and chemical resistance of these formable substrates are relatively poor. Therefore, in existing technologies, decorative films require a post-curing process after molding, involving the spraying of coatings containing volatile organic polymers (VOCs), to enhance their physical properties. However, the use of VOCs increases production costs and is less environmentally friendly.

[0003] In existing technologies, decorative films with higher hardness are more brittle and prone to cracking due to stress during processing. For example, while decorative films using methacrylate resins possess excellent physical properties and chemical resistance, their hardness and brittleness also affect their formability during processing, limiting design possibilities. Furthermore, to improve the formability of decorative films, existing technologies can involve applying a coating to a formable substrate and then performing only a solvent removal step without crosslinking or curing. After molding, post-curing is then used to achieve the necessary physical properties and chemical resistance. However, this post-curing process complicates the manufacturing process.

[0004] This invention proposes a curable resin composition for decorative films, which has good formability, and the decorative film formed by curing this curable resin composition does not require an additional post-curing process after molding to have appropriate hardness and excellent chemical resistance. Summary of the Invention

[0005] One object of the present invention is to provide a curable resin composition for decorative films, which has good formability and the decorative film formed after curing has appropriate hardness and excellent chemical resistance.

[0006] One object of the present invention is to provide a curable resin composition for decorative films, comprising: a (meth)acrylic resin having a weight average molecular weight greater than 80,000 and a glass transition temperature (Tg) greater than 80°C; a reactive (meth)acrylate composition comprising: a polyurethane (meth)acrylate oligomer with a functionality between 6 and 15 and a (meth)acrylate monomer; a first initiator, wherein the first initiator is a photopolymerization initiator; and a second initiator, wherein the second initiator is a peroxide, an azo compound, or a combination thereof; wherein the amount of the second initiator used is between 3 and 23 parts by weight per 100 parts by weight of the reactive (meth)acrylate composition, and the ratio of the amount of the first initiator to the amount of the second initiator is between 1:0.5 and 1:5.

[0007] In one embodiment of the invention, the amount of the second initiator used is between 5 and 22 parts by weight per 100 parts by weight of the reactive (meth)acrylate composition.

[0008] In one embodiment of the present invention, the first initiator may be, for example, an acetophenone initiator, a diphenyl ketone initiator, a phenylacetone initiator, a benzoyl initiator, a bifunctional α-hydroxy ketone initiator, an acylphosphine oxide initiator, or a combination thereof.

[0009] In one embodiment of the present invention, the first initiator may be, for example, 2,2-dimethoxy-2-diphenylethyl ketone, cyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propanone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, di(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 4-methylbenzophenone, or a combination thereof.

[0010] In one embodiment of the present invention, the peroxide may be, for example, hydrogen peroxide, ammonium persulfate, potassium persulfate, benzoyl peroxide, diisopropylbenzene peroxide, lauroyl peroxide, or a combination thereof.

[0011] In one embodiment of the invention, the azo compound may be, for example, azobisisobutyronitrile, azobisisoheptanenitrile, dimethyl azobisisobutyrate, or a combination thereof.

[0012] In one embodiment of the invention, the curable resin composition comprises: 35 to 80 parts by weight of the (meth)acrylic resin and 20 to 65 parts by weight of the reactive (meth)acrylic ester composition.

[0013] In one embodiment of the invention, the reactive (meth)acrylate composition comprises 10 to 35 parts by weight of the polyurethane (meth)acrylate oligomer with a functionality between 6 and 15 and 10 to 30 parts by weight of the (meth)acrylate monomer.

[0014] In one embodiment of the invention, the polyurethane (meth)acrylate oligomer with a functionality between 6 and 15 has a weight-average molecular weight between 1,800 and 15,000 and a viscosity (25°C) greater than 80,000 cps.

[0015] In one embodiment of the present invention, the polyurethane (meth)acrylate oligomer with a functionality between 6 and 15 is an aliphatic polyurethane (meth)acrylate oligomer with a functionality between 6 and 15.

[0016] In one embodiment of the present invention, the (meth)acrylate monomer may be, for example, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate (DPP(M)A), dipentaerythritol hexa(meth)acrylate (DPH(M)A), trimethylolpropane tri(meth)acrylate (TMPT(M)A), ditrimethylolpropane tetra(meth)acrylate (DTMPT(M)A), and pentaerythritol tri(meth)acrylate. tri(meth)acrylate, PET(M)A), 2-ethylhexyl(meth)acrylate, 2-EH(M)A), 2-hydroxyethyl(meth)acrylate, 2-HE(M)A), 3-hydroxypropyl(meth)acrylate, 3-HP(M)A, 4-hydroxybutyl(meth)acrylate, 4-HB(M)A, 2-butoxyethyl(meth)acrylate, 1,6-hexanediol di(meth)acrylate (1,6-hexanediol di(meth)acrylate (HDD(M)A), cyclic trimethylolpropane formal(meth)acrylate (CTF(M)A), 2-phenoxyethyl(meth)acrylate (PHE(M)A), tetrahydrofurfuryl(meth)acrylate (THF(M)A), lauryl(meth)acrylate (L(M)A), diethylene glycol di(meth)acrylate (DEGD(M)A), dipropylene glycol di(meth)acrylate (DPGD(M)A), tripropylene glycol di(meth)acrylate (TPGD(M)A), and isobornyl(meth)acrylate, or combinations thereof.

[0017] In one embodiment of the invention, the curable resin composition may further comprise a leveling agent.

[0018] In one embodiment of the invention, the amount of leveling agent used may be between 0.5% and 5% relative to the total weight of the curable resin composition.

[0019] Another object of the present invention is to provide a decorative film comprising a base film and the surface of the base film having a coating formed by curing the aforementioned curable resin composition.

[0020] Another object of the present invention is to provide a decorative film molded article, which is made by molding a decorative film as described above.

[0021] The foregoing summary is intended to provide a simplified overview of this disclosure, enabling the reader to gain a basic understanding. This summary is not a complete overview of the invention, nor is it intended to identify key components of the embodiments or define the scope of the invention. Upon reviewing the following embodiments, those skilled in the art will readily understand the basic spirit of the invention and the technical means and implementation methods employed. Detailed Implementation

[0022] To make the description of the present invention more detailed and complete, illustrative descriptions of the embodiments and specific examples of the present invention are provided below; however, these are not the only forms of implementing or using the specific examples of the present invention. The various embodiments disclosed below can be combined or substituted with each other where advantageous, and other embodiments can be added to one embodiment without further description or explanation.

[0023] The advantages, features, and technical methods of the present invention will be more readily understood by referring to exemplary embodiments, and the invention may be implemented in different forms. Therefore, it should not be understood as limited to the embodiments set forth herein. Rather, the embodiments provided will enable those skilled in the art to more thoroughly and completely convey the scope of the invention, and the invention will be defined only by the appended claims.

[0024] Unless otherwise defined, all terms (including technical and scientific terms) and proper nouns used below shall, in substance, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains, and those terms as defined in commonly used dictionaries shall be understood to have the same meaning as the content of the relevant field, and shall not be interpreted in an overly idealized or overly formal sense unless explicitly defined below.

[0025] Furthermore, in this article, "(meth)acrylic acid" refers to methacrylic acid and acrylic acid, and "(meth)acrylate" refers to methacrylate and acrylate.

[0026] One object of the present invention is to provide a curable resin composition for decorative films, comprising: (meth)acrylic resin, a reactive (meth)acrylate composition, a first initiator, and a second initiator. The first initiator is a photopolymerization initiator, and the second initiator is a peroxide, an azo compound, or a combination thereof. By adding the first and second initiators, the curable resin composition, after being coated onto a substrate and photocured, can be further cured during subsequent heating and molding processes to increase the degree of resin crosslinking, thereby improving the surface hardness and chemical resistance of the molded decorative film.

[0027] In one embodiment of the invention, the amount of the second initiator used relative to every 100 parts by weight of the reactive (meth)acrylate composition is between 3 and 23 parts by weight, and preferably between 5 and 22 parts by weight. The ratio of the amount of the first initiator to the amount of the second initiator is between 1:0.5 and 1:5. When the amount of the second initiator added is higher than the aforementioned range, it may affect the formability of the decorative film, causing cracks to appear on the surface of the molded decorative film. When the amount of the second initiator added is lower than the aforementioned range, the crosslinking density of the curable resin composition may be insufficient, thereby affecting the chemical resistance properties of the molded decorative film.

[0028] In one embodiment of the present invention, the first initiator may be a photoinitiator, such as acetophenone initiators, diphenyl ketone initiators, phenylacetone initiators, benzoyl initiators, bifunctional α-hydroxy ketone initiators, acylphosphine oxide initiators, or combinations thereof. Specifically, a suitable first initiator may be, for example, 2,2-dimethoxy-2-diphenylethyl ketone, cyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propanone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, di(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 4-methylbenzophenone, or combinations thereof, but is not limited thereto.

[0029] In one embodiment of the invention, the peroxide may be, for example, hydrogen peroxide, ammonium persulfate, potassium persulfate, benzoyl peroxide, dicumyl peroxide, lauroyl peroxide, or a combination thereof. The azo compound may be, for example, azobisisobutyronitrile, azobisisoheptanenitrile, dimethyl azobisisobutyrate, or a combination thereof, but is not limited thereto. The aforementioned peroxides and azo compounds may be used alone or in combination.

[0030] In one embodiment of the invention, the curable resin composition may comprise 35 to 80 parts by weight of (meth)acrylic resin and 20 to 65 parts by weight of a reactive (meth)acrylate composition. When the amount of (meth)acrylic resin added exceeds the aforementioned range, the hardness of the decorative film decreases, and its chemical resistance deteriorates. When the amount of (meth)acrylic resin added is below the aforementioned range, the formability of the decorative film will be affected, causing cracks to appear on the surface of the molded decorative film.

[0031] In the curable resin composition of the present invention, a suitable (meth)acrylic resin is a thermoplastic (meth)acrylic resin. A suitable (meth)acrylic resin has a weight-average molecular weight greater than 80,000 and a glass transition temperature (Tg) greater than 80°C.

[0032] In one embodiment of the invention, the reactive (meth)acrylate composition may comprise 10 to 35 parts by weight of a polyurethane (meth)acrylate oligomer with a functionality between 6 and 15 and 10 to 30 parts by weight of a (meth)acrylate monomer.

[0033] Suitable polyurethane (meth)acrylate oligomers with a functionality between 6 and 15 have a weight-average molecular weight between 1,800 and 15,000 and a viscosity (25°C) greater than 80,000 cps. In a preferred embodiment of the invention, the polyurethane (meth)acrylate oligomer with a functionality between 6 and 15 is an aliphatic polyurethane (meth)acrylate oligomer with a functionality between 6 and 15.

[0034] In the curable resin composition of the present invention, suitable (meth)acrylate monomers may be, for example, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate (DPP(M)A), dipentaerythritol hexa(meth)acrylate (DPH(M)A), trimethylolpropane tri(meth)acrylate (TMPT(M)A), ditrimethylolpropane tetra(meth)acrylate (DTMPT(M)A), and pentaerythritol tri(meth)acrylate. tri(meth)acrylate, PET(M)A), 2-ethylhexyl(meth)acrylate, 2-EH(M)A), 2-hydroxyethyl(meth)acrylate, 2-HE(M)A), 3-hydroxypropyl(meth)acrylate, 3-HP(M)A, 4-hydroxybutyl(meth)acrylate, 4-HB(M)A, 2-butoxyethyl(meth)acrylate, 1,6-hexanediol di(meth)acrylate (1,6-hexanediol di(meth)acrylate, HDD(M)A), cyclic trimethylolpropane formal(meth)acrylate, CTF(M)A, 2-phenoxyethyl(meth)acrylate, PHE(M)A, tetrahydrofurfuryl(meth)acrylate, THF(M)A, lauryl(meth)acrylate, L(M)A, diethylene glycol di(meth)acrylate, DEGD(M)A, dipropylene glycol di(meth)acrylate, DPGD(M)A, tripropylene glycol di(meth)acrylate, TPGD(M)A, or isobornyl(meth)acrylate, but not limited to these. The aforementioned monomers can be used alone or in combination.

[0035] In a preferred embodiment of the present invention, a leveling agent may be selectively added to the curable resin composition. Adding a leveling agent can improve the coating coverage or smoothness, and after the curable resin composition is coated and dried, it can exhibit better surface lubricity, antifouling properties, and abrasion resistance. Leveling agents that can be used in the curable resin composition of the present invention may be, for example, polyether-modified polysiloxanes, polyether-modified polyacrylates, fluorocarbon-modified polyacrylates, or perfluoroalkyl fluorinated surfactants. In one embodiment of the present invention, the amount of leveling agent used is approximately between 0.5% and 5% of the total weight of the curable resin composition.

[0036] Another object of the present invention is to provide a decorative film with good hardness and chemical resistance, comprising a base film and having a coating formed by curing a curable resin composition as described above on the surface of the base film.

[0037] Suitable base films can be any type of base film commonly used in this field, without particular limitation, such as polycarbonate films, polymethyl methacrylate films, polystyrene films, polyester films, polyurethane films, polyethylene terephthalate films, polyethylene films, PETG films, ABS resin films, or the like, but are not limited thereto.

[0038] The method for preparing the decorative film of the present invention includes mixing (meth)acrylic resin, reactive (meth)acrylic ester composition, first initiator and second initiator in a curable resin composition with a suitable solvent to form an acrylic coating solution; applying the acrylic coating solution onto a base film; drying and then curing by radiation or electron beam to form a decorative film on the base film.

[0039] The solvent used in the aforementioned method for preparing the decorative film of the present invention can be any organic solvent commonly used in this technical field, such as ketones, aliphatic or cycloaliphatic hydrocarbons, aromatic hydrocarbons, ethers, esters, or alcohols. One or more organic solvents can be used in the solution of the curable resin composition. Suitable solvents include, for example, acetone, butanone, cyclohexanone, methyl isobutyl ketone, hexane, cyclohexane, dichloromethane, dichloroethane, toluene, xylene, propylene glycol methyl ether, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, isopropanol, n-butanol, isobutanol, cyclohexanol, diacetone alcohol, propylene glycol methyl ether, propylene glycol methyl ether acetate, or tetrahydrofuran, or similar substances, but are not limited thereto.

[0040] The aforementioned method for applying acrylic coating solutions can employ, for example, roller coating, doctor blade coating, dip coating, roller coating, spin coating, slot coating, and other coating methods commonly used in this technical field, without any particular limitation.

[0041] Another object of the present invention is to provide a decorative film molded article, which is made by molding the aforementioned decorative film. In one embodiment of the present invention, the aforementioned decorative film molded article is obtained by placing the aforementioned decorative film in a molding mold, heating it in a vacuum forming machine, and performing vacuum forming, but is not limited thereto.

[0042] Compared to known decorative films, which either lack hardness or are limited by moldability and sacrifice complex designs, the decorative film of this invention has good moldability and chemical resistance. It can not only accommodate complex designs, but also produce molded products with surfaces that are not easily damaged. Therefore, it is suitable for applications such as the casing of mobile phone bodies or electronic products such as computers, interior panels of vehicles, or exterior casings.

[0043] The following embodiments are used to further illustrate the present invention, but the content of the present invention is not limited thereto.

[0044] Example

[0045] Example 1

[0046] 38.46 g of acrylic resin (M920, weight average molecular weight approximately 300,000, Tg 122°C, purchased from ROHM, Germany), 24.14 g of polyurethane acrylate oligomer (functionality 6, weight average molecular weight approximately 1,900, viscosity approximately 87,500 cps (25°C), purchased from IGM, Taiwan, China), 24.14 g of dipentaerythritol hexaacrylate (DPHA), and 3.44 g of photoinitiator (TR-PPI-One) were used. The following ingredients were mixed and stirred for 20 minutes to form an acrylic coating solution: 1.15 g of photoinitiator (Chemcure-BP, purchased from Heng Chiao Industry, Taiwan), 1.22 g of polyether-modified polydimethylsiloxane leveling agent (BYK-3710, purchased from BYK, Germany), 4.83 g of benzoyl peroxide (BPO, purchased from Juntian Chemical, Taiwan), 100 g of propylene glycol methyl ether (PM), and 300 g of butanone (MEK).

[0047] This acrylic coating solution was applied to one surface of a polymethyl methacrylate (PMMA) film with a thickness of 80 micrometers (μm), heated at 80°C for 4 minutes, and then subjected to a heat treatment of 200 mJ / cm. 2 UV lamps with radiation doses are used for photocuring to form a decorative film with a thickness of approximately 6 micrometers (μm) on the PMMA film.

[0048] The decorative film is placed in a vacuum forming machine (450DT, purchased from Formech, UK) along with a molding mold. It is heated at 160°C for 15 seconds and a vacuum is drawn to make the decorative film adhere tightly to the mold for vacuum forming, thus producing a decorative film molded product.

[0049] The obtained decorative film molded articles were subjected to hardness measurement, formability test and emulsion resistance test according to the methods described below. The test results are shown in Table 1 below.

[0050] Example 2

[0051] 48.25 g of methacrylic resin (MB-7033, weight average molecular weight approximately 95,000, Tg 85°C, purchased from Mitsubishi Chemical, Japan), 24.14 g of polyurethane acrylate oligomer (functionality 6, weight average molecular weight approximately 1,900, viscosity approximately 87,500 cps (25°C), purchased from IGM, Taiwan), 24.14 g of dipentaerythritol hexaacrylate (DPHA), 2.41 g of photoinitiator (Chemcure-481, purchased from Heng Chiao Industry, Taiwan), 1.01 g of polyether-modified polydimethylsiloxane leveling agent (BYK-3710, purchased from BYK, Germany), 4.83 g of benzoyl peroxide (BPO, purchased from Juntian Chemical, Taiwan), 100 g of propylene glycol methyl ether (PM), and 300 g of butanone (MEK) were mixed and stirred for 20 minutes to form an acrylic coating solution.

[0052] This acrylic coating solution was applied to one surface of a polymethyl methacrylate (PMMA) film with a thickness of 80 micrometers (μm), heated at 80°C for 4 minutes, and then subjected to a heat treatment of 200 mJ / cm. 2 UV lamps with radiation doses are used for photocuring to form a decorative film with a thickness of approximately 6 micrometers (μm) on the PMMA film.

[0053] The decorative film is placed in a vacuum forming machine (450DT, purchased from Formech, UK) along with a molding mold. It is heated at 160°C for 15 seconds and a vacuum is drawn to make the decorative film adhere tightly to the mold for vacuum forming, thus producing a decorative film molded product.

[0054] The obtained decorative film molded articles were subjected to hardness measurement, formability test and emulsion resistance test according to the method described below. The test results are shown in Table 1 below.

[0055] Example 3

[0056] 48.25 g of methacrylic resin (MB-7033, weight average molecular weight approximately 95,000, Tg 85°C, purchased from Mitsubishi Chemical, Japan) and 24.14 g of polyurethane acrylate oligomer (functionality 15, weight average molecular weight approximately 13,000, viscosity approximately 385,000 cps (25°C), purchased from Miwon Specialty) were used. The following ingredients were mixed and stirred for 20 minutes to form an acrylic coating solution: 24.14 g of dipentaerythritol hexaacrylate (DPHA), 2.41 g of photoinitiator (Chemcure-481, purchased from Heng Chiao Industry, Taiwan), 1.01 g of polyether-modified polydimethylsiloxane leveling agent (BYK-3710, purchased from BYK, Germany), 9.66 g of benzoyl peroxide (BPO, purchased from Juntian Chemical, Taiwan), 100 g of propylene glycol methyl ether (PM), and 300 g of butanone (MEK).

[0057] This acrylic coating solution was applied to one surface of a polymethyl methacrylate (PMMA) film with a thickness of 80 micrometers (μm), heated at 80°C for 4 minutes, and then subjected to a heat treatment of 200 mJ / cm. 2 UV lamps with radiation doses are used for photocuring to form a decorative film with a thickness of approximately 6 micrometers (μm) on the PMMA film.

[0058] The decorative film is placed in a vacuum forming machine (450DT, purchased from Formech, UK) along with a molding mold. It is heated at 160°C for 15 seconds and a vacuum is drawn to make the decorative film adhere tightly to the mold for vacuum forming, thus producing a decorative film molded product.

[0059] The obtained decorative film molded articles were subjected to hardness measurement, formability test and emulsion resistance test according to the methods described below. The test results are shown in Table 1 below.

[0060] Example 4

[0061] 48.25 g of methacrylic resin (MB-7033, weight average molecular weight approximately 95,000, Tg 85°C, purchased from Mitsubishi Chemical, Japan) and 24.14 g of polyurethane acrylate oligomer (functionality 15, weight average molecular weight approximately 13,000, viscosity approximately 385,000 cps (25°C), purchased from Miwon Specialty) were used. The following ingredients were mixed and stirred for 20 minutes to form an acrylic coating solution: 24.14 g of dipentaerythritol hexaacrylate (DPHA), 2.41 g of photoinitiator (Chemcure-481, purchased from Heng Chiao Industry, Taiwan), 1.01 g of polyether-modified polydimethylsiloxane leveling agent (BYK-3710, purchased from BYK, Germany), 7.24 g of benzoyl peroxide (BPO, purchased from Juntai Chemical, Taiwan), 100 g of propylene glycol methyl ether (PM), and 300 g of butanone (MEK).

[0062] This acrylic coating solution was applied to one surface of a polymethyl methacrylate (PMMA) film with a thickness of 80 micrometers (μm), heated at 80°C for 4 minutes, and then subjected to a heat treatment of 200 mJ / cm. 2 UV lamps with radiation doses are used for photocuring to form a decorative film with a thickness of approximately 6 micrometers (μm) on the PMMA film.

[0063] The decorative film is placed in a vacuum forming machine (450DT, purchased from Formech, UK) along with a molding mold. It is heated at 160°C for 15 seconds and a vacuum is drawn to make the decorative film adhere tightly to the mold for vacuum forming, thus producing a decorative film molded product.

[0064] The obtained decorative film molded articles were subjected to hardness measurement, formability test and emulsion resistance test according to the methods described below. The test results are shown in Table 1 below.

[0065] Example 5

[0066] 48.25 g of methacrylic resin (MB-7033, weight average molecular weight approximately 95,000, Tg 85°C, purchased from Mitsubishi Chemical, Japan) and 24.14 g of polyurethane acrylate oligomer (functionality 15, weight average molecular weight approximately 13,000, viscosity approximately 385,000 cps (25°C), purchased from Miwon Specialty) were used. The following ingredients were mixed and stirred for 20 minutes to form an acrylic coating solution: 24.14 g of dipentaerythritol hexaacrylate (DPHA), 2.41 g of photoinitiator (Chemcure-481, purchased from Heng Chiao Industrial Co., Ltd., Taiwan), 1.01 g of polyether-modified polydimethylsiloxane leveling agent (BYK-3710, purchased from BYK, Germany), 10.62 g of azobisisobutyronitrile (AIBN, purchased from Shirakawa Chemical Industry Co., Ltd., Taiwan), 100 g of propylene glycol methyl ether (PM), and 300 g of butanone (MEK).

[0067] This acrylic coating solution was applied to one surface of a polymethyl methacrylate (PMMA) film with a thickness of 80 micrometers (μm), heated at 80°C for 4 minutes, and then subjected to a heat treatment of 200 mJ / cm. 2 UV lamps with radiation doses are used for photocuring to form a decorative film with a thickness of approximately 6 micrometers (μm) on the PMMA film.

[0068] The decorative film is placed in a vacuum forming machine (450DT, purchased from Formech, UK) along with a molding mold. It is heated at 160°C for 15 seconds and a vacuum is drawn to make the decorative film adhere tightly to the mold for vacuum forming, thus producing a decorative film molded product.

[0069] The obtained decorative film molded articles were subjected to hardness measurement, formability test and emulsion resistance test according to the methods described below. The test results are shown in Table 1 below.

[0070] Example 6

[0071] 48.25 g of methacrylic resin (MB-7033, weight average molecular weight approximately 95,000, Tg 85°C, purchased from Mitsubishi Chemical, Japan) and 24.14 g of polyurethane acrylate oligomer (functionality 15, weight average molecular weight approximately 13,000, viscosity approximately 385,000 cps (25°C), purchased from Miwon Specialty) were used. The following ingredients were mixed and stirred for 20 minutes to form an acrylic coating solution: 24.14 g of dipentaerythritol hexaacrylate (DPHA), 2.41 g of photoinitiator (Chemcure-481, purchased from Heng Chiao Industrial Co., Ltd., Taiwan), 1.01 g of polyether-modified polydimethylsiloxane leveling agent (BYK-3710, purchased from BYK, Germany), 7.24 g of azobisisobutyronitrile (AIBN, purchased from Shirakawa Chemical Industry Co., Ltd., Taiwan), 100 g of propylene glycol methyl ether (PM), and 300 g of butanone (MEK).

[0072] This acrylic coating solution was applied to one surface of a polymethyl methacrylate (PMMA) film with a thickness of 80 micrometers (μm), heated at 80°C for 4 minutes, and then subjected to a heat treatment of 200 mJ / cm. 2 UV lamps with radiation doses are used for photocuring to form a decorative film with a thickness of approximately 6 micrometers (μm) on the PMMA film.

[0073] The decorative film is placed in a vacuum forming machine (450DT, purchased from Formech, UK) along with a molding mold. It is heated at 160°C for 15 seconds and a vacuum is drawn to make the decorative film adhere tightly to the mold for vacuum forming, thus producing a decorative film molded product.

[0074] The obtained decorative film molded articles were subjected to hardness measurement, formability test and emulsion resistance test according to the methods described below. The test results are shown in Table 1 below.

[0075] Example 7

[0076] 48.25 g of methacrylic resin (MB-7033, weight average molecular weight approximately 95,000, Tg 85°C, purchased from Mitsubishi Chemical, Japan) and 24.14 g of polyurethane acrylate oligomer (functionality 15, weight average molecular weight approximately 13,000, viscosity approximately 385,000 cps (25°C), purchased from Miwon Specialty) were used. The following ingredients were mixed and stirred for 20 minutes to form an acrylic coating solution: 24.14 g of dipentaerythritol hexaacrylate (DPHA), 2.41 g of photoinitiator (Chemcure-481, purchased from Heng Chiao Industrial Co., Ltd., Taiwan), 1.01 g of polyether-modified polydimethylsiloxane leveling agent (BYK-3710, purchased from BYK, Germany), 2.41 g of azobisisobutyronitrile (AIBN, purchased from Shirakawa Chemical Industry Co., Ltd., Taiwan), 100 g of propylene glycol methyl ether (PM), and 300 g of butanone (MEK).

[0077] This acrylic coating solution was applied to one surface of a polymethyl methacrylate (PMMA) film with a thickness of 80 micrometers (μm), heated at 80°C for 4 minutes, and then subjected to a heat treatment of 200 mJ / cm. 2 UV lamps with radiation doses are used for photocuring to form a decorative film with a thickness of approximately 6 micrometers (μm) on the PMMA film.

[0078] The decorative film is placed in a vacuum forming machine (450DT, purchased from Formech, UK) along with a molding mold. It is heated at 160°C for 15 seconds and a vacuum is drawn to make the decorative film adhere tightly to the mold for vacuum forming, thus producing a decorative film molded product.

[0079] The obtained decorative film molded articles were subjected to hardness measurement, formability test and emulsion resistance test according to the methods described below. The test results are shown in Table 1 below.

[0080] Comparative Example 1

[0081] 48.25 g of methacrylic resin (MB-7033, weight average molecular weight approximately 95,000, Tg 85°C, purchased from Mitsubishi Chemical, Japan), 24.14 g of polyurethane acrylate oligomer (functionality 6, weight average molecular weight approximately 1,900, viscosity approximately 87,500 cps (25°C), purchased from Miwon Specialty Chemical, South Korea), 24.14 g of dipentaerythritol hexaacrylate (DPHA), 2.41 g of photoinitiator (Chemcure-481, purchased from Heng Chiao Industry, Taiwan, China), 1.01 g of polyether-modified polydimethylsiloxane leveling agent (BYK-3710, purchased from BYK, Germany), 100 g of propylene glycol methyl ether (PM), and 300 g of butanone (MEK) were mixed and stirred for 20 minutes to form an acrylic coating solution.

[0082] This acrylic coating solution was applied to one surface of a polymethyl methacrylate (PMMA) film with a thickness of 80 micrometers (μm), heated at 80°C for 4 minutes, and then subjected to a heat treatment of 200 mJ / cm. 2 UV lamps with radiation doses are used for photocuring to form a decorative film with a thickness of approximately 6 micrometers (μm) on the PMMA film.

[0083] The decorative film is placed in a vacuum forming machine (450DT, purchased from Formech, UK) along with a molding mold. It is heated at 160°C for 15 seconds and a vacuum is drawn to make the decorative film adhere tightly to the mold for vacuum forming, thus producing a decorative film molded product.

[0084] The obtained decorative film molded articles were subjected to hardness measurement, formability test and emulsion resistance test according to the methods described below. The test results are shown in Table 1 below.

[0085] Comparative Example 2

[0086] 48.25 g of methacrylic resin (MB-7033, weight average molecular weight approximately 95,000, Tg 85°C, purchased from Mitsubishi Chemical, Japan) and 24.14 g of polyurethane acrylate oligomer (functionality 15, weight average molecular weight approximately 13,000, viscosity approximately 385,000 cps (25°C), purchased from Miwon Specialty) were used. The following ingredients were mixed and stirred for 20 minutes to form an acrylic coating solution: 24.14 g of dipentaerythritol hexaacrylate (DPHA), 2.41 g of photoinitiator (Chemcure-481, purchased from Heng Chiao Industry, Taiwan), 1.01 g of polyether-modified polydimethylsiloxane leveling agent (BYK-3710, purchased from BYK, Germany), 12.1 g of benzoyl peroxide (BPO, purchased from Juntian Chemical, Taiwan), 100 g of propylene glycol methyl ether (PM), and 300 g of butanone (MEK).

[0087] This acrylic coating solution was applied to one surface of a polymethyl methacrylate (PMMA) film with a thickness of 80 micrometers (μm), heated at 80°C for 4 minutes, and then subjected to a heat treatment of 200 mJ / cm. 2 UV lamps with radiation doses are used for photocuring to form a decorative film with a thickness of approximately 6 micrometers (μm) on the PMMA film.

[0088] The decorative film is placed in a vacuum forming machine (450DT, purchased from Formech, UK) along with a molding mold. It is heated at 160°C for 15 seconds and a vacuum is drawn to make the decorative film adhere tightly to the mold for vacuum forming, thus producing a decorative film molded product.

[0089] The obtained decorative film molded articles were subjected to hardness measurement, formability test and emulsion resistance test according to the methods described below. The test results are shown in Table 1 below.

[0090] Comparative Example 3

[0091] 33.25 g of acrylic resin (M920, weight average molecular weight approximately 300,000, Tg 122°C, purchased from ROHM, Germany), 24.14 g of polyurethane acrylate oligomer (functionality 6, weight average molecular weight approximately 1,900, viscosity approximately 87,500 cps (25°C), purchased from IGM, Taiwan, China), 24.14 g of dipentaerythritol hexaacrylate (DPHA), and 3.44 g of photoinitiator (TR-PPI-One) were used. The following ingredients were mixed and stirred for 20 minutes to form an acrylic coating solution: 1.15 g of photoinitiator (Chemcure-BP, purchased from Heng Chiao Industry, Taiwan), 1.22 g of polyether-modified polydimethylsiloxane leveling agent (BYK-3710, purchased from BYK, Germany), 4.83 g of benzoyl peroxide (BPO, purchased from Juntian Chemical, Taiwan), 100 g of propylene glycol methyl ether (PM), and 300 g of butanone (MEK).

[0092] This acrylic coating solution was applied to one surface of a polymethyl methacrylate (PMMA) film with a thickness of 80 micrometers (μm), heated at 80°C for 4 minutes, and then subjected to a heat treatment of 200 mJ / cm. 2 UV lamps with radiation doses are used for photocuring to form a decorative film with a thickness of approximately 6 micrometers (μm) on the PMMA film.

[0093] The decorative film is placed in a vacuum forming machine (450DT, purchased from Formech, UK) along with a molding mold. It is heated at 160°C for 15 seconds and a vacuum is drawn to make the decorative film adhere tightly to the mold for vacuum forming, thus producing a decorative film molded product.

[0094] The obtained decorative film molded articles were subjected to hardness measurement, formability test and emulsion resistance test according to the methods described below. The test results are shown in Table 1 below.

[0095] Evaluation methods for hardness measurement, moldability testing, and emulsion resistance testing

[0096] Pencil Hardness Measurement: The pencil hardness of the surface of the decorative film molded product was measured based on the description in JIS K5400. The measurement method involved applying a 750g load using an automatic pencil hardness tester (instrument model 553-M, manufactured by Yasuda Seiki Seisakusho Co., Ltd.), and moving a Mitsubishi hardness pencil at a speed of 1 mm / s to measure the pencil hardness of the decorative film molded product. If two or more scratches were found, the decorative film molded product was deemed defective, and the maximum hardness that passed the test was recorded.

[0097] Formability test: Check whether cracks appear on the surface of the decorative film after vacuum forming. If there are no cracks on the surface, it is rated as (O) and if there are cracks on the surface, it is rated as (X).

[0098] Emulsion (chemical resistance) test: After applying sunscreen (SPF50+, purchased from Kanebo, Taiwan, China) to the surface of the decorative film molded product, heat it at 80°C for 4 hours, wipe the emulsion off the surface of the decorative film molded product with a lint-free cloth, and then observe whether there are any residual marks or deformations on the surface of the decorative film molded product. If there are no residual marks on the surface, it is evaluated as pass; if there are residual marks on the surface, it is evaluated as NG.

[0099] Table 1: Pencil hardness, formability, and emulsion resistance test results of decorative films of the examples and comparative examples

[0100]

[0101]

[0102] As shown in Table 1, the decorative film molded products prepared in Examples 1 to 7 not only have good formability and hardness, but also have good chemical resistance without the need for additional post-curing.

[0103] Although the present invention has been disclosed above by way of embodiments, it is not intended to limit the present invention. Those skilled in the art can make various modifications and changes without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A curable resin composition for a decorative film, comprising: 35 to 80 parts by weight of a (meth)acrylic resin, wherein the (meth)acrylic resin has a weight average molecular weight of greater than 80,000 and a glass transition temperature of greater than 80°C; 20 to 65 parts by weight of a reactive (meth)acrylate composition, comprising: a polyurethane (meth)acrylate oligomer having a functionality of between 6 and 15; and a (meth)acrylate monomer; a first initiator, wherein the first initiator is a photopolymerization initiator; and a second initiator, wherein the second initiator is a peroxide, an azo compound, or a combination thereof; wherein the second initiator is used in an amount of between 3 and 23 parts by weight per hundred parts by weight of the reactive (meth)acrylate composition, and the ratio of the amount used of the first initiator to the amount used of the second initiator is between 1 :0.5 and 1 :

5.

2. The curable resin composition for a decorative film of claim 1, wherein the second initiator is used in an amount of between 5 and 22 parts by weight per hundred parts by weight of the reactive (meth)acrylate composition.

3. The curable resin composition for a decorative film of claim 1, wherein the first initiator is selected from at least one of the group consisting of an acetophenone-based initiator, a benzophenone-based initiator, a benzoin-phenone-based initiator, a dibenzoyl-based initiator, a bifunctional a-hydroxyketone-based initiator, and an acylphosphine oxide-based initiator, or a combination thereof.

4. The curable resin composition for a decorative film of claim 1, wherein the first initiator is selected from at least one of the group consisting of 2,2-dimethoxy-2-diphenylacetophenone, cyclohexyl phenyl ketone, 2-hydroxy-2-methyl-l-phenyl-l-propanone, l-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-l-propanone, 2-methyl-l-[4-(methylthio)phenyl]-2-morpholin-1-propanone, 2-benzyl-2-dimethylamino-l-(4-morpholinophenyl)-l-butanone, bis(2,4,6-trimethylbenzoyl)phosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, 4-methylbenzophenone, or a combination thereof.

5. The curable resin composition for a decorative film of claim 1, wherein the peroxide is selected from at least one of the group consisting of hydrogen peroxide, ammonium persulfate, potassium persulfate, benzoyl peroxide, dicumyl peroxide, lauryl peroxide, or a combination thereof.

6. The curable resin composition for a decorative film of claim 1, wherein the azo compound is azobisisobutyronitrile, azobisisoheptanenitrile, dimethyl azobis isobutyrate, or a combination thereof.

7. The curable resin composition for a decorative film of claim 1, wherein the reactive (meth)acrylate composition comprises: 10 to 35 parts by weight of the polyurethane (meth)acrylate oligomer having a functionality of between 6 and 15; and 10 to 30 parts by weight of the (meth)acrylate monomer.

8. The curable resin composition for a decorative film according to claim 1, wherein the polyurethane (meth) acrylate oligomer having a functionality of 6 to 15 has a weight average molecular weight of 1,800 to 15,000 and a viscosity of more than 80,000 cps at 25°C.

9. The curable resin composition for a decorative film according to claim 1, wherein the polyurethane (meth) acrylate oligomer having a functionality of 6 to 15 is an aliphatic polyurethane (meth) acrylate oligomer.

10. The curable resin composition for a decorative film according to claim 1, wherein the (meth) acrylate monomer is at least one selected from the group consisting of pentaerythritol tetra(meth) acrylate, dipentaerythritol penta(meth) acrylate, dipentaerythritol hexa(meth) acrylate, trimethylolpropane tri(meth) acrylate, ditrimethylolpropane tetra(meth) acrylate, pentaerythritol tri(meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-butoxyethyl (meth) acrylate, 1,6-hexanediol di(meth) acrylate, cyclotrimethylolpropane formal (meth) acrylate, 2-phenoxyethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, lauryl (meth) acrylate, diethylene glycol di(meth) acrylate, dipropylene glycol di(meth) acrylate, tripropylene glycol di(meth) acrylate, and isobornyl (meth) acrylate, or a combination thereof.

11. The curable resin composition for a decorative film according to claim 1, further comprising a leveling agent.

12. The curable resin composition for a decorative film according to claim 11, wherein the leveling agent is used in an amount of 0.5% to 5% relative to the total weight of the curable resin composition.

13. A decorative film comprising a base film having a coating layer formed by curing the curable resin composition for a decorative film according to any one of claims 1 to 12 on the surface of the base film.

14. A molded product of a decorative film, which is molded using the decorative film according to claim 13.

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