Cured film and molded article

Abstract

This cured film is an active energy-curing cured film formed by curing a thin film with a thickness of 1-20 µm on at least a part of the surface of a transparent substrate. The cured film has a value of 0.2-0.3 for the ratio A / B between (A) the peak intensity at 1625 cm-1 detected by measurement using ATR FT-IR (total reflectance Fourier transform infrared spectroscopy) analysis and (B) the peak intensity at 1726 cm-1.

Description

Cured film and molded body

[0001] The present invention relates to a cured film and a molded article.

[0002] Transparent synthetic resins such as polycarbonate resin (PC) and polymethyl methacrylate resin (PMMA) have excellent transparency, moldability, and mechanical properties, and are therefore used in many fields, such as outer lenses (translucent covers) for lamps in automobiles and motorcycles, eyeglass lenses, optical sensor covers, and various liquid crystal panels. However, when the surface temperature of a molded product such as a synthetic resin falls below the dew point temperature, moisture in the air condenses as fine droplets, causing fogging. This reduces light transmittance, leading to problems such as poor visibility and malfunction of sensors, etc. To prevent such problems, transparency is ensured by applying a composition to the surface of the molded product to form a cured film.

[0003] For example, Patent Document 1 discloses an anti-fog coating composition characterized by containing a copolymer formed from a monomer mixture containing a vinyl monomer having an N-methylol group or an N-alkoxymethylol group, a vinyl monomer having a sulfonic acid group, and an alkyl(meth)acrylate monomer, a basic compound, and a surfactant.

[0004] JP 2011-140589 A

[0005] However, the cured film obtained by curing such a composition may be insufficiently cured, and when exposed to high-temperature steam, for example, uncured components may leach out, causing drip marks, which may reduce the transparency of the substrate on which the cured film is formed, resulting in problems such as poor visibility and malfunction of sensors, etc.

[0006] The present invention has been made in view of the above points, and has an object to provide a cured film and a molded article that suppress the occurrence of water drip marks.

[0007] The cured film of the present invention is an active energy curable cured film that is thinly cured to a thickness of 1 μm to 20 μm on at least a part of the surface of a transparent substrate, and the cured film has a wavelength of 1625 cm detected by FT-IR analysis ATR method (attenuated total reflection Fourier transform infrared spectroscopy). －１ Peak intensity (A) and 1726 cm －１ The ratio A / B of the peak intensity (B) of the peak intensity (B) is 0.2 or more and 0.3 or less.

[0008] Fig. 1 is a conceptual diagram showing a molded article of the present invention; Fig. 2 is a diagram showing a manufacturing process for a molded article of the present invention; Fig. 3 is an FT-IR chart obtained when a cured film of the present invention is measured by FT-IR analysis ATR method (total reflection Fourier transform infrared spectroscopy); Fig. 4 is a FT-IR chart obtained when an active energy curable composition is measured by FT-IR analysis ATR method (total reflection Fourier transform infrared spectroscopy) －１ Peak intensity (A) and 1726 cm －１ 1 is a graph showing the correlation between the ratio A / B of the peak intensity (A) to the peak intensity (B) of the active energy-curable composition and the curing reaction rate (%) of the active energy-curable composition.

[0009] An embodiment of the present invention will be described. The cured film 10 of the present invention is obtained by thin-film curing of an active energy-curable composition containing a polyfunctional acrylate, a hydrophilic acrylate, and an initiator. The film thickness of the cured film 10 is 1 μm to 20 μm.

[0010] The polyfunctional acrylate is a highly reactive, hydrophobic, radically reactive material. By including the polyfunctional acrylate in the active energy ray-curable composition, the curing rate of the active energy ray-curable composition can be increased. Furthermore, the highly reactive polyfunctional acrylate cures, and the hydrophilic acrylate having a hydrophilic group cures later. Therefore, the polyfunctional acrylate, which is compatible with the hydrophobic substrate, adheres to the substrate 20, and the hydrophilic acrylate, which cures later, tends to be located on the outermost surface. Therefore, a thin film of hydrophilic acrylate can be applied to the surface of the cured film 10, improving anti-fogging properties.

[0011] Because polyfunctional acrylates are hydrophobic, when applied to a hydrophobic substrate 20, they can improve the adhesion between the active energy ray-curable composition and the substrate. This can prevent the cured film 10 from peeling off from the substrate 20. Furthermore, the high adhesion between the cured film 10 and the substrate 20 can also prevent cracks from occurring in low-temperature environments. This allows a cured film 10 with excellent durability to be formed on the substrate 20.

[0012] The content of the polyfunctional acrylate is preferably 15% by mass or more and less than 80% by mass based on the total amount of the active energy ray-curable composition. If the content of the polyfunctional acrylate is less than 15% by mass, sufficient adhesion to the hydrophobic substrate cannot be ensured. On the other hand, if the content of the polyfunctional acrylate is 80% by mass or more, the proportion of hydrophilic groups is relatively reduced, making it impossible to impart sufficient antifogging properties to the substrate.

[0013] Examples of polyfunctional acrylates that can be used include pentaerythritol tetraacrylate, PEG200 diacrylate, pentaerythritol hexaacrylate, pentaerythritol triacrylate, pentaerythritol alkoxytetraacrylate, pentaerythritol ethoxytetraacrylate, PEG400 diacrylate, and PEG600 diacrylate.

[0014] The hydrophilic acrylate is a radical-reactive material composed of a resin component such as a monomer or oligomer. When the active energy ray-curable composition is applied to the surface of a substrate 20 (e.g., a polycarbonate resin), at least a portion of the hydrophilic acrylate is disposed in the surface layer of the active energy ray-curable composition. Then, by curing the active energy ray-curable composition through a radical reaction, a cured film 10 having hydrophilic properties can be formed on the surface of the substrate.

[0015] This reduces the contact angle with water on the surface of the molded body 30 having the cured film 10 formed on the surface of the substrate 20. Thus, moisture diffuses onto the surface of the molded body (cured film) to form a water film, ensuring the anti-fogging properties of the substrate.

[0016] The content of the hydrophilic acrylate is preferably 10% by mass or more and less than 50% by mass relative to the total amount of the active energy ray-curable composition. If the content of the hydrophilic acrylate is less than 10% by mass relative to the total amount of the active energy ray-curable composition, sufficient hydrophilic function cannot be ensured on the surface of the cured film, and fogging of the substrate cannot be prevented. On the other hand, if the content of the hydrophilic acrylate is 90% by mass or more, sufficient adhesion to the hydrophobic substrate cannot be ensured.

[0017] Examples of hydrophilic acrylates that can be used include glycerol dimethacrylate, polyethylene glycol diacrylate, polyethylene glycol triacrylate, glycerol 1,2-diacrylate, glycerol 1,3-diacrylate, and N,N-diethylacrylamide. These radical reactive materials may be used alone or in combination of two or more.

[0018] The initiator is a radical generator that generates highly active radicals upon irradiation with ultraviolet light. These radical species undergo decomposition and react with resin components such as monomers and / or oligomers. This reaction product then reacts with other resin components, causing a chain reaction to proceed. The crosslinking reaction then proceeds, increasing the molecular weight and curing the radical-reactive material and polyfunctional acrylate to form a cured film.

[0019] The content of the initiator is preferably 1% by mass or more and less than 15% by mass relative to the total amount of the active energy ray-curable composition. If the content of the initiator is less than 1% by mass, the active energy ray-curable composition will not be cured sufficiently, resulting in poor curing. On the other hand, if the content of the initiator is 15% by mass or more, the molecular weight will not increase, resulting in insufficient strength of the cured film.

[0020] Examples of initiators that can be used include 1-hydroxycyclohexyl phenyl ketone, 2-benzyl-2-(dimethylamino)-4'-morpholinobutyrophenone, 2-hydroxy-1-[4-(2-hydroxyethoxy)phenyl]-2-methyl-1-propanone, and 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)-2-methylpropan-1-one. It is also preferable to use two or more of these initiators in combination. By using two or more of these initiators in combination, the curing reaction rate of the active energy ray-curable composition can be improved.

[0021] In addition to the initiator, the active energy ray-curable composition may contain various additives such as an antibacterial agent, an antifungal agent, an antifoaming agent, an antioxidant, an antistatic agent, a dye, a polymerization inhibitor, an ultraviolet absorber, a light stabilizer, and a leveling agent.

[0022] Examples of antibacterial agents include captan, carbendazim, quinomethionate, chlorothalonil, clozolinate, cyprodinil, epoxiconazole, famoxadone, fenarimol, fenbuconazole, fenfuram, fenpiclonil, azoxystrobin, benalaxyl, benomyl, bitertanol, fluazinam, fludioxonil, fluorimide, fluquinconazole, flusulfamide, flutolanil, folpet, Hexachlorobenzene, hexaconazole, ipoconazole, iprodione, kresoxim methyl, manzeb, maneb, mepanipyrim, mepronil, metconazole, metiram, phthalide, procymidone, propineb, quintozene, tecnazene, thifluzamide, thiophenate methyl, thiram, tolclofos methyl, tolylfluanid, triadimefon, triadimenol, triazoxide, triforine, etc. can be used. Inorganic antibacterial agents can also be used, for example, silver, copper, zinc, tin, lead, gold, etc. Furthermore, synthetic antibacterial agents can also be used, for example, polyhexamethylene hyguanide, hydrochloride, benzethonium chloride, alkylpolyaminoethylglycine, benzisothiazoline, etc.

[0023] Examples of the antifungal agent that can be used include sodium dehydroacetate, sodium benzoate, sodium pyridinethione-1-oxide, p-hydroxybenzoic acid ethyl ester, 1,2-benzisothiazolin-3-one and salts thereof.

[0024] Examples of the defoaming agent that can be used include fatty acid salts, liquid fatty oil sulfates, higher alcohol sulfates, fatty alcohol phosphates, fatty acid amide sulfonates, sulfonates of dibasic fatty acid esters, alkylarylsulfonates, polyoxyethylene alkyl ethers, polyoxyethylene alkylphenol ethers, polyoxyethylene alkyl esters, sorbitan alkyl esters, polyoxyethylene sorbitan alkyl esters, acrylic polymers, vinyl polymers, and organopolysiloxanes.

[0025] Examples of the antioxidant that can be used include phenol-based antioxidants, phosphorus-based antioxidants, and sulfur-based antioxidants. Examples of the phenol-based antioxidant include 2,6-di-tert-butyl-p-cresol, stearyl β-(3',5'-di-tert-butyl-4-hydroxyphenyl)propionate, and 1,3,5-trimethyl-2,4,6-tris(3',5'-di-tert-butyl-4-hydroxybenzyl)benzene. Examples of the phosphorus-based antioxidant include tris(2,4-di-tert-butylphenyl)phosphite, diphenylmono(2-ethylhexyl)phosphite, 2,2'-methylenebis(4,6-di-tert-butylphenyl)-2-ethylhexyl phosphite, distearyl pentaerythritol diphosphite, and tri(mononylphenyl)phosphite. Examples of sulfur-based antioxidants that can be used include dilauryl-3,3'-thiodipropionate and pentaerythritol tetrakis(3-laurylthiopropionate).

[0026] Examples of the antistatic agent that can be used include various cationic antistatic agents having a cationic group such as a primary to tertiary amino group, a quaternary ammonium salt, or a pyridinium salt; anionic antistatic agents having an anionic group such as a sulfonate group, a sulfate group, a phosphate group, or a phosphonate group; amphoteric antistatic agents such as amino acid-based or amino sulfate-based; nonionic antistatic agents such as amino alcohol-based, glycerin-based, or polyethylene glycol-based; and polymeric antistatic agents obtained by increasing the molecular weight of the above-mentioned antistatic agents.

[0027] Examples of dyes that can be used include pyrazole azo compounds, anilino azo compounds, triarylmethane compounds, anthraquinone compounds, anthrapyridone compounds, benzylidene compounds, oxonol compounds, pyrazolotriazole azo compounds, pyridone azo compounds, cyanine compounds, phenothiazine compounds, pyrrolopyrazole azomethine compounds, xanthene compounds, phthalocyanine compounds, benzopyran compounds, indigo compounds, and pyrromethene compounds.

[0028] A polymerization inhibitor may be added to prevent the double bond from reacting. Examples of the polymerization inhibitor include hydroquinone (HQ), hydroquinone monomethyl ether (MEHQ), 2,6-di-t-butyl-4-methylphenol (BHT), t-butylcatechol (TBC), and phenol or naphthol derivatives such as 4-methoxy-1-naphthol, phenothiazine derivatives, and nitrosamine salts.

[0029] Examples of ultraviolet absorbers that can be used include octyl methoxycinnamate, dimethoxybenzylidene dioxoimidazolidine octyl propionate, diethylaminohydroxybenzoylhexyl benzoate, t-butylmethoxydibenzoylmethane, octyl triazone, and 2-ethylhexyl paramethoxycinnamate.

[0030] Examples of light stabilizers that can be used include salicylate-based light stabilizers, benzophenone-based light stabilizers, benzotriazole-based light stabilizers, hindered amine-based light stabilizers, cyanoacrylate-based light stabilizers, oxalic acid anilide-based light stabilizers, and nickel-based quenchers.

[0031] As the leveling agent, for example, a silicon-based leveling agent, an acrylic-based leveling agent, an ester compound, a ketone compound, a fluorine compound, or the like can be used.

[0032] Using Figure 2, a method for producing a molded body 30 having a cured film 10 formed on the surface of a substrate 20 by curing an active energy ray-curable composition will be described. First, the active energy ray-curable composition was loaded into a paint gun (S1). Then, the substrate 20 to be coated was fixed to a painting jig (S2). The active energy ray-curable composition was applied to the surface of the substrate 20 with the paint gun to a uniform film thickness of 10 µm (S3). The active energy ray-curable composition was irradiated with ultraviolet light (S4). The active energy ray-curable composition was cured on the surface of the substrate 20 to form a cured film 10 (S5). As described above, a molded body 30 having a cured film 10 formed on the surface of the substrate 20 by curing an active energy ray-curable composition can be produced.

[0033] When applying the active energy ray-curable composition to the surface of the substrate 20, the composition may be applied to a part of the surface of the substrate 20, or may be applied to the entire surface of the substrate 20. In other words, the cured film 10 may be formed on a part of the surface of the substrate 20, or may be formed on the entire surface of the substrate 20.

[0034] In this embodiment, the active energy ray-curable composition is applied to a uniform film thickness of 10 μm to form a uniform cured film 10 of 10 μm on the surface of the substrate 20, but the film thickness may be 1 μm to 20 μm, and preferably 10 μm to 18 μm. A film thickness of 10 μm or more can further improve the curing reaction rate of the active energy ray-curable composition.

[0035] Furthermore, the method for applying the active energy ray-curable composition is not limited to a coating gun, and application methods using an inkjet or a dispenser may also be employed.

[0036] The substrate 20 may be made of a transparent material such as polycarbonate resin (PC), hydrophobic synthetic resin such as polymethyl methacrylate resin (PMMA), or glass.

[0037] The cured film 10 can be used as an anti-fogging coating, and the molded article 30 can be used as an outer lens (translucent cover) of a vehicle lamp, a window glass, a lens of glasses, a cover for the surface of an optical sensor, etc.

[0038] The cured film 10 has a wavelength of 1625 cm detected by FT-IR analysis ATR method (attenuated total reflection Fourier transform infrared spectroscopy). －１ Peak intensity A and wavelength 1726 cm －１ The ratio A / B of the peak intensity B to the peak intensity A (hereinafter referred to as "A / B value") is 0.2 or more and 0.3 or less.

[0039] 3 shows an FT-IR chart detected by measuring the cured film 10 of the present invention by the FT-IR analysis ATR method (attenuated total reflection Fourier transform infrared spectroscopy). The measurement was carried out using a Fourier transform infrared spectrophotometer (model: IRXross) manufactured by Shimadzu Corporation as the measuring device, and a diamond prism.

[0040] As shown by the solid line in FIG. 3, the cured film 10 of this embodiment was measured by the FT-IR analysis ATR method at a wavelength of 1625 cm －１ The peak intensity (A) of the (right dotted line) is 0.1, and the wavelength is 1726 cm －１ The peak intensity (B) of the peak (dotted line on the left) is 0.4. In other words, the A / B value of the cured film 10 of this embodiment is 0.25.

[0041] 4 is a graph showing the correlation between the A / B value and the curing reaction rate of an active energy-curable composition. As shown in FIG. 4, the A / B value has a high correlation with the curing reaction rate of the active energy-curable composition. Since this correlation is a negative correlation, the lower the A / B value, the higher the curing reaction rate of the active energy-curable composition tends to be.

[0042] Therefore, the wavelength is 1625 cm －１ Peak intensity (A) and wavelength 1726 cm －１ A cured film having a ratio A / B of 0.2 or more to the peak intensity (B) of the active energy-curable composition has a high curing reaction rate of the active energy-curable composition, and can suppress the occurrence of water drip marks due to insufficient curing of the active energy-curable composition. Furthermore, an A / B value of 0.2 or more can prevent a decrease in the anti-fogging function (hydrophilic function).

[0043] On the other hand, for example, the cured film shown by the dashed line in FIG. －１ The peak intensity (A) of the (right dotted line) is 0.13, and the wavelength is 1726 cm －１ The peak intensity (B) of the curve (dotted line on the left) is 0.35. In other words, the A / B value of this cured film is 0.37. When this type of cured film is exposed to high-temperature steam, the uncured components of the active energy-curable composition are eluted due to insufficient curing, causing drip marks. This is primarily caused by insufficient curing of the active energy-curable composition.

[0044] Wavelength 1625cm －１ Peak intensity (A) and wavelength 1726 cm －１ The ratio A / B of the peak intensity (A) to the peak intensity (B) of the active energy-curable composition is more preferably 0.23 or more and 0.27 or less. When the A / B value is 0.27 or less, the curing reaction rate of the active energy-curable composition is further improved, and the occurrence of water drip marks can be further suppressed.

[0045] The cured film 10 of the present invention has a change rate of the A / B value before and after acetone washing of less than 10%. Here, the measurement after acetone washing is performed by washing the cured film 10 with acetone (CH ３ COCH ３) for 5 seconds, and then left at room temperature (approximately 25°C) for 10 minutes, after which measurement was performed using the FT-IR analysis ATR method. The change in A / B value of cured film 10 before and after acetone washing was less than 10%, indicating that cured film 10 has excellent chemical resistance.

[0046] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[0047] Example 1 To a 300 mL separable flask equipped with a stirring blade, 65 parts by mass of pentaerythritol tetraacrylate (product code: P2084, manufactured by Tokyo Chemical Industry Co., Ltd.) as a polyfunctional acrylate and 30 parts by mass of glycerol dimethacrylate (product code: B2938, manufactured by Tokyo Chemical Industry Co., Ltd.) as a hydrophilic acrylate were added. Next, 5 parts by mass of 2-benzyl-2-(dimethylamino)-4'-morpholinobutyrophenone (product name: Omnirad369, manufactured by Sanyo Trading Co., Ltd.) as an initiator were added. This was stirred at room temperature for 30 minutes to obtain 100 parts by mass of an active energy ray-curable composition. This was applied to the surface of a substrate and cured with UV light to obtain a test specimen having the cured film of Example 1 with a film thickness of 8 μm.

[0048] Example 2: 60 parts by mass of PEG200 diacrylate (product name: PEG200DA, manufactured by Daicel Allnex Corporation) as a multifunctional acrylate and 25 parts by mass of polyethylene glycol diacrylate (product code: P2708, manufactured by Tokyo Chemical Industry Co., Ltd.) as a hydrophilic acrylate were added to a 300 mL separable flask equipped with a stirring blade. Next, 15 parts by mass of 1-hydroxycyclohexyl phenyl ketone (product name: Omnirad184, manufactured by Sanyo Trading Co., Ltd.) as an initiator were added. This was stirred at room temperature for 30 minutes to obtain 100 parts by mass of an active energy ray-curable composition. This was applied to the surface of a substrate and cured with UV light to obtain a test specimen having the cured film of Example 2 with a film thickness of 10 μm.

[0049] Example 3 65 parts by mass of pentaerythritol tetraacrylate (product code: P2084, manufactured by Tokyo Chemical Industry Co., Ltd.) as a polyfunctional acrylate and 30 parts by mass of glycerol dimethacrylate (product code: B2938, manufactured by Tokyo Chemical Industry Co., Ltd.) as a hydrophilic acrylate were added to a 300 mL separable flask equipped with a stirring blade. Next, 5 parts by mass of 2-benzyl-2-(dimethylamino)-4'-morpholinobutyrophenone (product name: Omnirad369, manufactured by Sanyo Trading Co., Ltd.) as an initiator were added. This was stirred at room temperature for 30 minutes to obtain 100 parts by mass of an active energy ray-curable composition. This was applied to the surface of a substrate and cured with UV light to obtain a test specimen having the cured film of Example 3 with a film thickness of 10 μm.

[0050] Example 4 65 parts by mass of pentaerythritol hexaacrylate (product code: D5688, manufactured by Tokyo Chemical Industry Co., Ltd.) as a polyfunctional acrylate and 30 parts by mass of polyethylene glycol diacrylate (product code: P2708, manufactured by Tokyo Chemical Industry Co., Ltd.) as a hydrophilic acrylate were added to a 300 mL separable flask equipped with a stirring blade. Next, 5 parts by mass of 1-hydroxycyclohexyl phenyl ketone (product name: Omnirad184, manufactured by Sanyo Trading Co., Ltd.) as an initiator were added. This was stirred at room temperature for 30 minutes to obtain 100 parts by mass of an active energy ray-curable composition. This was applied to the surface of a substrate and cured with UV light to obtain a test specimen having the cured film of Example 4 with a film thickness of 10 μm.

[0051] Example 5: 70 parts by mass of pentaerythritol tetraacrylate (product code: P2084, manufactured by Tokyo Chemical Industry Co., Ltd.) as a polyfunctional acrylate and 29 parts by mass of polyethylene glycol triacrylate (product code: P2708, manufactured by Tokyo Chemical Industry Co., Ltd.) as a hydrophilic acrylate were added to a 300 mL separable flask equipped with a stirring blade. Next, 1 part by mass of 2-hydroxy-1-[4-(2-hydroxyethoxy)phenyl]-2-methyl-1-propanone (product name: Omnirad2959, manufactured by Sanyo Trading Co., Ltd.) as an initiator was added. This mixture was stirred at room temperature for 30 minutes to obtain 100 parts by mass of an active energy ray-curable composition. This was applied to the surface of a substrate and cured with UV light to obtain a test specimen having the cured film of Example 5 with a film thickness of 10 μm.

[0052] Example 6 To a 300 mL separable flask equipped with a stirring blade, 65 parts by mass of pentaerythritol triacrylate (product code: P2084, manufactured by Tokyo Chemical Industry Co., Ltd.) as a multifunctional acrylate and 32 parts by mass of glycerol dimethacrylate (product name: B2938, manufactured by Kyoeisha Chemical Co., Ltd.) as a hydrophilic acrylate were added. Next, 3 parts by mass of 1-hydroxycyclohexyl phenyl ketone (product name: Omnirad184, manufactured by Sanyo Trading Co., Ltd.) as an initiator were added. This was stirred at room temperature for 30 minutes to obtain 100 parts by mass of an active energy ray-curable composition. This was applied to the surface of a substrate and cured with UV light to obtain a test specimen having the cured film of Example 6 with a film thickness of 10 μm.

[0053] Example 7 A 300 mL separable flask equipped with a stirring blade was charged with 50 parts by mass of pentaerythritol alkoxytetraacrylate (product name: EBECRYL 40, manufactured by Daicel-Allnex Corporation) as a polyfunctional acrylate and 48 parts by mass of glycerol 1,2-diacrylate (product code: B2938, manufactured by Tokyo Chemical Industry Co., Ltd.) as a hydrophilic acrylate. Next, 2 parts by mass of 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)-2-methylpropan-1-one (product name: Omnirad127, manufactured by Sanyo Trading Co., Ltd.) as an initiator. The mixture was stirred at room temperature for 30 minutes to obtain 100 parts by mass of an active energy ray-curable composition. This was applied to the surface of a substrate and cured with UV light to obtain a test specimen having the cured film of Example 7 with a film thickness of 10 μm.

[0054] Example 8 68 parts by mass of pentaerythritol ethoxy tetraacrylate (product name: P2084, manufactured by Tokyo Chemical Industry Co., Ltd.) as a polyfunctional acrylate and 30 parts by mass of glycerol 1,3-diacrylate (product code: B2938, manufactured by Tokyo Chemical Industry Co., Ltd.) as a hydrophilic acrylate were added to a 300 mL separable flask equipped with a stirring blade. Next, 2 parts by mass of 2-hydroxy-1-[4-(2-hydroxyethoxy)phenyl]-2-methyl-1-propanone (product name: Omnirad2959, manufactured by Sanyo Trading Co., Ltd.) as an initiator were added. The mixture was stirred at room temperature for 30 minutes to obtain 100 parts by mass of an active energy ray-curable composition. This was applied to the surface of a substrate and cured with UV light to obtain a test specimen having the cured film of Example 8 with a film thickness of 10 μm.

[0055] Example 9: 80 parts by mass of PEG200 diacrylate (product name: PEG200DA, manufactured by Daicel Allnex Corporation) as a multifunctional acrylate and 15 parts by mass of polyethylene glycol diacrylate (product code: P2708, manufactured by Tokyo Chemical Industry Co., Ltd.) as a hydrophilic acrylate were added to a 300 mL separable flask equipped with a stirring blade. Next, 5 parts by mass of 1-hydroxycyclohexyl phenyl ketone (product name: Omnirad184, manufactured by Sanyo Trading Co., Ltd.) as an initiator were added. This was stirred at room temperature for 30 minutes to obtain 100 parts by mass of an active energy ray-curable composition. This was applied to the surface of a substrate and cured with UV light to obtain a test specimen having the cured film of Example 9 with a film thickness of 10 μm.

[0056] Example 10: 75 parts by mass of PEG400 diacrylate (product name: PEG400DA, manufactured by Daicel Allnex Corporation) as a multifunctional acrylate and 20 parts by mass of N,N-diethylacrylamide (product code: D3737, manufactured by Tokyo Chemical Industry Co., Ltd.) as a hydrophilic acrylate were added to a 300 mL separable flask equipped with a stirring blade. Next, 5 parts by mass of 1-hydroxycyclohexyl phenyl ketone (product name: Omnirad184, manufactured by Sanyo Trading Co., Ltd.) as an initiator were added. This was stirred at room temperature for 30 minutes to obtain 100 parts by mass of an active energy ray-curable composition. This was applied to the surface of a substrate and cured with UV light to obtain a test specimen having the cured film of Example 10 with a film thickness of 10 μm.

[0057] Example 11 70 parts by mass of PEG 600 diacrylate (product name: EBECRYL 11, manufactured by Daicel Allnex Corporation) as a multifunctional acrylate and 25 parts by mass of glycerol 1,3-diacrylate (product code: B2938, manufactured by Tokyo Chemical Industry Co., Ltd.) as a hydrophilic acrylate were added to a 300 mL separable flask equipped with a stirring blade. Next, 5 parts by mass of 2-benzyl-2-(dimethylamino)-4'-morpholinobutyrophenone (product name: Omnirad369, manufactured by Sanyo Trading Co., Ltd.) as an initiator were added. This was stirred at room temperature for 30 minutes to obtain 100 parts by mass of an active energy ray-curable composition. This was applied to the surface of a substrate and cured with UV light to obtain a test specimen having the cured film of Example 11 with a film thickness of 10 μm.

[0058] Example 12 20 parts by mass of pentaerythritol tetraacrylate (product code: P2084, manufactured by Tokyo Chemical Industry Co., Ltd.) and 43 parts by mass of PEG 600 diacrylate (product name: EBECRYL 11, manufactured by Daicel-Allnex Corporation) as multifunctional acrylates, and 30 parts by mass of glycerol dimethacrylate (product name: B2938, manufactured by Kyoeisha Chemical Co., Ltd.) as hydrophilic acrylate were added to a 300 mL separable flask equipped with a stirring blade. Next, 7 parts by mass of 2-benzyl-2-(dimethylamino)-4'-morpholinobutyrophenone (product name: Omnirad369, manufactured by Sanyo Trading Co., Ltd.) as an initiator were added. This was stirred at room temperature for 30 minutes to obtain 100 parts by mass of an active energy ray-curable composition. This was applied to the surface of a substrate and cured with UV light to obtain a test specimen having the cured film of Example 12 with a film thickness of 10 μm.

[0059] Example 13 A 300 mL separable flask equipped with a stirring blade was charged with 15 parts by mass of pentaerythritol alkoxytetraacrylate (product name: EBECRYL 40, manufactured by Daicel-Allnex Corporation) and 25 parts by mass of pentaerythritol hexaacrylate (product code: D5688, manufactured by Tokyo Chemical Industry Co., Ltd.) as multifunctional acrylates, and 21 parts by mass of glycerol 1,2-diacrylate (product code: B2938, manufactured by Tokyo Chemical Industry Co., Ltd.) and 20 parts by mass of glycerol dimethacrylate (product name: B2938, manufactured by Kyoeisha Chemical Co., Ltd.) as hydrophilic acrylates. Next, 9 parts by mass of 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)-2-methylpropan-1-one (product name: Omnirad127, manufactured by Sanyo Trading Co., Ltd.) was added as an initiator. This was stirred at room temperature for 30 minutes to obtain 100 parts by mass of an active energy ray-curable composition, which was then applied to the surface of a substrate and cured by UV to obtain a test piece having a cured film of Example 13 with a film thickness of 10 μm.

[0060] Example 14: 50 parts by mass of PEG400 diacrylate (product name: PEG400DA, manufactured by Daicel-Allnex Corporation) as a multifunctional acrylate, 20 parts by mass of N,N-diethylacrylamide (product code: D3737, manufactured by Tokyo Chemical Industry Co., Ltd.) as a hydrophilic acrylate, and 23 parts by mass of glycerol dimethacrylate (product name: B2938, manufactured by Kyoeisha Chemical Co., Ltd.) were added to a 300 mL separable flask equipped with a stirring blade. Next, 7 parts by mass of 2-hydroxy-1-[4-(2-hydroxyethoxy)phenyl]-2-methyl-1-propanone (product name: Omnirad2959, manufactured by Sanyo Trading Co., Ltd.) as an initiator were added. The mixture was stirred at room temperature for 30 minutes to obtain 100 parts by mass of an active energy ray-curable composition. This was applied to the surface of a substrate and cured with UV light to obtain a test specimen having the cured film of Example 14 with a film thickness of 10 μm.

[0061] Example 15 A 300 mL separable flask equipped with a stirring blade was charged with 30 parts by mass of pentaerythritol ethoxy tetraacrylate (product name: P2084, manufactured by Tokyo Chemical Industry Co., Ltd.) and 40 parts by mass of PEG200 diacrylate (product name: PEG200DA, manufactured by Daicel-Allnex Corporation) as multifunctional acrylates, and 24 parts by mass of glycerol 1,2-diacrylate (product code: B2938, manufactured by Tokyo Chemical Industry Co., Ltd.) as a hydrophilic acrylate. Next, 6 parts by mass of 2-hydroxy-1-[4-(2-hydroxyethoxy)phenyl]-2-methyl-1-propanone (product name: Omnirad2959, manufactured by Sanyo Trading Co., Ltd.) as an initiator. The mixture was stirred at room temperature for 30 minutes, yielding 100 parts by mass of an active energy ray-curable composition. This was applied to the surface of the substrate and cured with UV light to obtain a test piece having a cured film of Example 15 with a film thickness of 10 μm.

[0062] Example 16 A 300 mL separable flask equipped with a stirring blade was charged with 30 parts by mass of pentaerythritol ethoxy tetraacrylate (product name: P2084, manufactured by Tokyo Chemical Industry Co., Ltd.) and 40 parts by mass of PEG200 diacrylate (product name: PEG200DA, manufactured by Daicel-Allnex Corporation) as multifunctional acrylates, and 24 parts by mass of glycerol 1,2-diacrylate (product code: B2938, manufactured by Tokyo Chemical Industry Co., Ltd.) as a hydrophilic acrylate. Next, 6 parts by mass of 2-hydroxy-1-[4-(2-hydroxyethoxy)phenyl]-2-methyl-1-propanone (product name: Omnirad2959, manufactured by Sanyo Trading Co., Ltd.) as an initiator. The mixture was stirred at room temperature for 30 minutes, yielding 100 parts by mass of an active energy ray-curable composition. This was applied to the surface of the substrate and cured with UV light to obtain a test piece having a cured film of Example 15 with a film thickness of 15 μm.

[0063] Example 17: 80 parts by mass of pentaerythritol hexaacrylate (product code: D5688, manufactured by Tokyo Chemical Industry Co., Ltd.) as a polyfunctional acrylate and 15 parts by mass of polyethylene glycol diacrylate (product code: P2708, manufactured by Tokyo Chemical Industry Co., Ltd.) as a hydrophilic acrylate were added to a 300 mL separable flask equipped with a stirring blade. Next, 3 parts by mass of 1-hydroxycyclohexyl phenyl ketone (product name: Omnirad184, manufactured by Sanyo Trading Co., Ltd.) as an initiator and 2 parts by mass of 2-hydroxy-1-[4-(2-hydroxyethoxy)phenyl]-2-methyl-1-propanone (product name: Omnirad2959, manufactured by Sanyo Trading Co., Ltd.) were added. The mixture was stirred at room temperature for 30 minutes to obtain 100 parts by mass of an active energy ray-curable composition. This was applied to the surface of a substrate and cured with UV light to obtain a test specimen having the cured film of Example 17 with a film thickness of 10 μm.

[0064] Example 18 A 300 mL separable flask equipped with a stirring blade was charged with 40 parts by mass of PEG400 diacrylate (product name: PEG400DA, manufactured by Daicel-Allnex Corporation) and 20 parts by mass of pentaerythritol tetraacrylate (product code: P2084, manufactured by Tokyo Chemical Industry Co., Ltd.) as multifunctional acrylates, and 20 parts by mass of glycerol dimethacrylate (product name: B2938, manufactured by Kyoeisha Chemical Co., Ltd.) and 29 parts by mass of polyethylene glycol triacrylate (product code: P2708, manufactured by Tokyo Chemical Industry Co., Ltd.) and 20 parts by mass of polyethylene glycol triacrylate (product code: P2708, manufactured by Tokyo Chemical Industry Co., Ltd.) as hydrophilic acrylates. Next, 5 parts by mass of 2-benzyl-2-(dimethylamino)-4'-morpholinobutyrophenone (product name: Omnirad369, manufactured by Sanyo Trading Co., Ltd.) and 5 parts by mass of 2-hydroxy-1-[4-(2-hydroxyethoxy)phenyl]-2-methyl-1-propanone (product name: Omnirad2959, manufactured by Sanyo Trading Co., Ltd.) were added as initiators. This was stirred at room temperature for 30 minutes to obtain 100 parts by mass of an active energy ray-curable composition. This was applied to the surface of a substrate and cured with UV light to obtain a test piece having a cured film of Example 18 with a film thickness of 10 μm.

[0065] Example 19: 80 parts by mass of pentaerythritol hexaacrylate (product code: D5688, manufactured by Tokyo Chemical Industry Co., Ltd.) as a polyfunctional acrylate and 13 parts by mass of polyethylene glycol diacrylate (product code: P2708, manufactured by Tokyo Chemical Industry Co., Ltd.) as a hydrophilic acrylate were added to a 300 mL separable flask equipped with a stirring blade. Next, 3 parts by mass of 1-hydroxycyclohexyl phenyl ketone (product name: Omnirad184, manufactured by Sanyo Trading Co., Ltd.) as an initiator and 4 parts by mass of 2-hydroxy-1-[4-(2-hydroxyethoxy)phenyl]-2-methyl-1-propanone (product name: Omnirad2959, manufactured by Sanyo Trading Co., Ltd.) were added. The mixture was stirred at room temperature for 30 minutes to obtain 100 parts by mass of an active energy ray-curable composition. This was applied to the surface of a substrate and cured with UV light to obtain a test specimen having the cured film of Example 19 with a film thickness of 15 μm.

[0066] Comparative Example 1 To a 300 mL separable flask equipped with a stirring blade, 30 parts by mass of EO-modified bisphenol A diacrylate (product name: EBECRYL 150, manufactured by Daicel-Allnex Corporation) as a multifunctional acrylate and 50 parts by mass of N,N-diethylacrylamide (product code: D3737, manufactured by Tokyo Chemical Industry Co., Ltd.) as a hydrophilic acrylate were added. Next, 20 parts by mass of 2-benzyl-2-(dimethylamino)-4'-morpholinobutyrophenone (product name: Omnirad369, manufactured by Sanyo Trading Co., Ltd.) as an initiator were added. This was stirred at room temperature for 30 minutes to obtain 100 parts by mass of an active energy ray-curable composition. This was applied to the surface of a substrate and cured with UV light to obtain a test specimen having a cured film of Comparative Example 1 with a film thickness of 1 μm.

[0067] Comparative Example 2: 60 parts by weight of polyester polyol (product name: Polylite OD-X-2420, manufactured by DIC Corporation) as the main component and 10 parts by weight of polyethylene glycol diacrylate (product code: P2708, manufactured by Tokyo Chemical Industry Co., Ltd.) as the curing agent were added to a 300 mL separable flask equipped with a stirring blade. Next, 30 parts by weight of methyl isobutyl ketone (product name: WM44-L70G, manufactured by Asahi Kasei Corporation) as the solvent was added. This mixture was stirred at room temperature for 30 minutes to obtain 100 parts by weight of a thermosetting composition. This was applied to the surface of a substrate and cured by heating at 80°C for 40 minutes to obtain a test piece having a cured film of Comparative Example 2 with a film thickness of 15 μm.

[0068] (Measurement of A / B Value) The cured films of Examples 1 to 19 and the cured film of Comparative Example 1 were measured by FT-IR analysis ATR method (attenuated total reflection Fourier transform infrared spectroscopy) to obtain an FT-IR chart. －１ Peak intensity (A) and wavelength 1726 cm －１ The ratio A / B of the peak intensity (A) to the peak intensity (B) of the peak intensity (B) was calculated. The measurement was performed using a Fourier transform infrared spectrophotometer (model: IRXross) manufactured by Shimadzu Corporation, and a diamond prism. Figure 5 shows the A / B values ​​for Examples 1 to 19 and Comparative Example 1.

[0069] (Change in A / B value after acetone washing) The cured films of Examples 1 to 19 and the cured film of Comparative Example 1 were measured by FT-IR analysis ATR method (attenuated total reflection Fourier transform infrared spectroscopy) to obtain FT-IR charts. －１ Peak intensity (A) and wavelength 1726 cm －１ The A / B value before washing with acetone was determined by calculating the ratio A / B of the peak intensity (B) of the peak intensity (B) of the cured film of Examples 1 to 19 or the cured film of Comparative Example 1. ３ COCH ３) for 5 seconds, and then left at room temperature (about 25°C) for 10 minutes. Next, the cured film was measured by FT-IR analysis ATR method (attenuated total reflection Fourier transform infrared spectroscopy) to obtain an FT-IR chart. Next, from the obtained FT-IR chart, －１ Peak intensity (A) and wavelength 1726 cm －１ The A / B value after acetone washing was determined by calculating the ratio A / B of the peak intensity (A) to the peak intensity (B) of the sample. Figure 5 shows the rate of change in A / B value after acetone washing for Examples 1 to 19 and Comparative Example 1. The measurement was carried out using a Fourier transform infrared spectrophotometer (model: IRXross) manufactured by Shimadzu Corporation as the measuring device, and a diamond prism.

[0070] The rate of change in the A / B value after acetone washing was calculated using the following formula 1: Rate of change (%) = |(A / B value after washing−A / B value before washing) / A / B value before washing×100| (1)

[0071] (Evaluation of Dissolution Properties) Test pieces having the cured films of Examples 1 to 19 or Comparative Example 1 were placed on a hot plate heated to 90°C, and 20 μL of pure water heated to 50°C was dropped onto the test piece. The pure water was then evaporated and the visible traces of the drop were visually observed to evaluate the dissolution properties on a 5-point scale (A to E). The evaluation was based on the following criteria: A when no traces of the eluted components were visible; B when partial traces of the eluted components were visible; C when thin, spreading traces of the eluted components were visible; D when traces of the eluted components were clearly visible; and E when light was not transmitted due to the eluted components. The evaluation results of dissolution properties for Examples 1 to 19 and Comparative Example 1 are summarized in FIG. 5 .

[0072] (Evaluation of Anti-Fog Properties) Test pieces having the cured films of Examples 1 to 19 or Comparative Example 1 were immersed in warm water at 40°C for 240 hours. The test pieces were then dried at room temperature, and breath was blown onto the test pieces at room temperature. The surface area of ​​the test pieces where fogging occurred was visually confirmed to evaluate the anti-fogging properties on a 5-point scale of A to E. The evaluation was rated as follows: A if no fogging occurred on the test piece; B if about 10% of the surface area of ​​the test piece was fogging; C if about 50% of the surface area of ​​the test piece was fogging; D if about 80% of the surface area of ​​the test piece was fogging; and E if the entire surface area of ​​the test piece was fogging. The evaluation results of the anti-fogging properties of Examples 1 to 19 and Comparative Example 1 are summarized in FIG. 5 .

[0073] From Figure 5, it is clear that the active energy ray-curable compositions of Examples 1 to 19 ensure sufficient curing reaction rates, since the A / B values ​​of the cured films are 0.2 or more and 0.3 or less. Furthermore, the rate of change in the A / B value after acetone washing is 9% or less, ensuring excellent chemical resistance. Furthermore, in the evaluation of elution, even if traces of eluted components are visible, they are only thin and spread, ensuring excellent elution. In other words, water drip marks caused by elution of uncured components when high-temperature steam hits the cured film are suppressed. In this specification, "excellent elution" means that the components contained in the active energy ray-curable composition are unlikely to be eluted.

[0074] From the results of Examples 2 to 19, when a cured film having a thickness of 10 μm or more was formed, the A / B value was 0.28 or less, which clearly shows that the reactivity of the active energy ray-curable composition was further improved. Furthermore, due to the improved reactivity of the active energy ray-curable composition, even if traces of eluted components were visible in the elution evaluation, they were only partial, which clearly shows that better elution was ensured. Furthermore, the rate of change in the A / B value after acetone washing was 8% or less, which clearly shows that better chemical resistance was ensured.

[0075] From the results of Examples 16 and 19, when the thickness of the cured film formed was 15 μm or more, the A / B value was 0.26 or less, which clearly shows that the reactivity of the active energy ray-curable composition was further improved. Furthermore, due to the improved reactivity of the active energy ray-curable composition, no traces of eluted components were visible in the elution evaluation, which clearly shows that even better elution was ensured. Furthermore, the change rate of the A / B value after acetone washing was 4% or less, which clearly shows that even better chemical resistance was ensured.

[0076] From the results of Examples 17 to 19, when two or more initiators were used, the A / B value was 0.26 or less, which clearly shows that the reactivity of the active energy ray-curable composition was further improved. Furthermore, due to the improved reactivity of the active energy ray-curable composition, no traces of eluted components were visible in the elution evaluation, which clearly shows that even better elution was ensured. Furthermore, the rate of change in the A / B value after acetone washing was 4% or less, which clearly shows that even better chemical resistance was ensured.

[0077] From the results of Example 19, it is clear that when a cured film having a thickness of 15 μm or more was formed and two or more initiators were used, the A / B value was 0.25 or less, and therefore the reactivity of the active energy ray-curable composition was further improved.

[0078] In contrast, in Comparative Example 1, in which the blending amount of the polyfunctional acrylate was as low as 30 parts by mass and the content of the hydrophilic acrylate was as high as 50 parts by mass, poor curing occurred, as can be seen from the A / B value of 0.37. Furthermore, the change rate of the A / B value after acetone washing was 50%, indicating that sufficient chemical resistance was not ensured. Furthermore, in the evaluation of elution, the eluted components were clearly visible, and the eluted components prevented the transmission of LED light, indicating that sufficient elution was not ensured. Furthermore, in the anti-fogging evaluation, the entire surface area of ​​the test piece was fogged, clearly indicating that sufficient anti-fogging properties were not ensured.

[0079] Similarly, in Comparative Example 2, which is a thermosetting composition, in the evaluation of elution, eluted components were clearly visible to the naked eye, and the eluted components prevented transmission of LED light, so sufficient elution was not ensured. Furthermore, in the anti-fogging evaluation, about 80% of the surface area of ​​the test piece was fogged, clearly indicating that sufficient anti-fogging properties were not ensured.

[0080] As described above, the cured film of the present invention can suppress the occurrence of water drip marks.

[0081] 10 Cured film 20 Base material 30 Molded object

Claims

1. An active energy curable cured film that is thinly cured to a thickness of 1 μm to 20 μm on at least a part of the surface of a transparent substrate, wherein the cured film has a wavelength of 1625 cm detected by FT-IR analysis ATR method (total reflection Fourier transform infrared spectroscopy). －１ Peak intensity (A) and 1726 cm －１ A cured film having a ratio A / B of 0.2 or more and 0.3 or less to a peak intensity (B) of the peak intensity (A / B).

2. The cured film according to claim 1, wherein the rate of change in the value of the ratio A / B before and after acetone washing is less than 10%.

3. The cured film according to claim 1, wherein the ratio A / B is 0.23 or more and 0.27 or less.

4. The cured film according to claim 1, which is cured as a thin film having a thickness of 10 μm to 18 μm on at least a portion of the surface of the transparent substrate.

5. The cured film according to claim 1, wherein the transparent substrate is a polymethyl methacrylate resin or a polycarbonate resin.

6. A transparent substrate; and an active energy curable cured film cured in a thin film having a thickness of 1 μm to 20 μm on at least a part of the surface of the transparent substrate, wherein the cured film has a wavelength of 1625 cm detected by FT-IR analysis ATR method (total reflection Fourier transform infrared spectroscopy). －１ Peak intensity (A) and 1726 cm －１ The molded article has a ratio A / B of 0.2 or more and 0.3 or less to the peak intensity (B) of the peak intensity (A / B).

7. The molded article according to claim 6, which is an outer lens of a vehicle lamp.

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