Cured film, lens, and inspection method

Abstract

The objective is to provide a cured film, a lens, and a method for inspecting a cured film, all of which ensure good adhesion to a substrate. [Solution] An active energy curing type cured film that covers at least a portion of the surface of a substrate, wherein the cured film has a ratio A / B of 0.2 or more and less than 0.55 between the peak area (A) due to C=C stretching vibration originating from vinyl groups and the peak area (B) due to C=O stretching vibration originating from ester groups, as detected by FT-IR analysis ATR method, and the peak areas (A) and (B) are determined by the peak area in the wavelength band from the short wavelength side to the long wavelength side of the full width at half maximum of each peak (P1, P2), and the peel strength of the substrate and the cured film by surface-interface cutting method is 0.0005 N or more.

Description

Technical Field

[0001] The present invention relates to a cured film, a lens, and an inspection method.

Background Art

[0002] Synthetic resins such as polycarbonate resin (PC) and polymethyl methacrylate resin (PMMA) are excellent in transparency, moldability, and mechanical properties. Therefore, they are used in many fields such as lenses (light-transmitting covers) for automotive and motorcycle lamps, spectacle lenses, covers for optical sensors, and various liquid crystal panels. However, on the surface of molded articles such as synthetic resins, when the surface temperature drops below the dew point temperature, moisture in the atmosphere condenses into fine water droplets, causing cloudiness. As a result, there is a problem of reducing the light transmittance, causing poor visibility and malfunction of sensors. In addition, when scratches or dirt adhere to the surface of a molded article such as a synthetic resin, there is also a problem of reducing the light transmittance, causing poor visibility and malfunction of sensors. To prevent such problems, a cured film is formed by applying a composition to the surface of a molded article (substrate) such as a synthetic resin and curing it to ensure transparency (anti-fogging performance, scratch resistance, etc.).

[0003] For example, Patent Document 1 discloses a hard coat film in which a bonding underlayer mainly composed of a photopolymerization initiator is provided on the surface of a cellulose ester film substrate, and a hard coat layer forming composition layer made of an active energy ray curable resin composition containing 10 to 95% by weight of a compound having two or more (meth)acryloyl groups by a curing reaction of the resin by the photopolymerization initiator is provided on the surface of the bonding underlayer, and the cellulose ester film substrate and the hard coat layer are integrally bonded by a curing reaction of the resin by the photopolymerization initiator, wherein when the resin reaction rate at the surface of the hard coat layer is (A) and the resin reaction rate at the interface between the cellulose ester film substrate and the hard coat layer bonded thereto by a curing reaction of the photopolymerization initiator is (B), the surface resin reaction rate (A) is 60% or more, and the relationship between the surface resin reaction rate (A) and the interface resin reaction rate (B) satisfies the condition that surface resin reaction rate (A) - interface resin reaction rate (B) < 30 (%). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2009-241256 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, the relationship between the resin reaction rate and the adhesion at the surface interface between the substrate and the cured film remains unclear. Therefore, sufficient adhesion was not ensured, raising concerns about the cured film peeling off the substrate.

[0006] The present invention has been made in view of the above points, and aims to provide a cured film, a lens, and a method for inspecting a cured film that ensures adhesion to a substrate. [Means for solving the problem]

[0007] The cured film of the present invention is An active energy curable film that covers at least a portion of the surface of a substrate, The cured film has a ratio A / B of 0.2 or more and less than 0.55 between the peak area (A) due to C=C stretching vibration originating from vinyl groups and the peak area (B) due to C=O stretching vibration originating from ester groups, as detected by FT-IR analysis ATR method. The aforementioned peak areas (A) and (B) are determined by the area of ​​the peaks in the wavelength band from the short-wavelength side to the long-wavelength side of the full width at half maximum of each peak. The peel strength between the substrate and the cured film by surface-interface cutting is 0.0005 N or greater. [Brief explanation of the drawing]

[0008] [Figure 1] This is a conceptual diagram showing a molded article having a cured film according to the present invention. [Figure 2] This figure shows the manufacturing process for a molded article having a cured film according to the present invention. [Figure 3] This is an FT-IR chart obtained when the cured film of the present invention was measured using FT-IR analysis (ATR method: total reflection Fourier transform infrared spectroscopy). [Figure 4] This graph shows the correlation between the ratio A / B of the peak area due to C=C stretching vibrations originating from vinyl groups (A) and the peak area due to C=O stretching vibrations originating from ester groups (B), which are detected by measuring the cured film of the present invention using FT-IR analysis ATR method (Total Reflectance Fourier Transform Infrared Spectroscopy), and the peel strength of the substrate and the cured film by surface-interface cutting. [Figure 5] This table summarizes the comparison results between examples and comparative examples of the cured film of the present invention. [Modes for carrying out the invention]

[0009] Embodiments of the present invention will now be described. The cured film 10 of the present invention is a cured film obtained by thin-film curing an active energy curable composition containing an acrylate, a hydrophilic monomer, and an initiator onto at least a portion of the surface of a substrate 20. In other words, the cured film 10 covers at least a portion of the surface of the substrate 20. The thickness of the cured film 10 is 1 μm to 20 μm.

[0010] Acrylate is a highly reactive, hydrophobic, radical-reactive material. By including acrylate in an active energy ray-curable composition, the curing speed of the active energy ray-curable composition can be accelerated. Furthermore, the highly reactive acrylate cures first, followed later by the hydrophilic monomers that have hydrophilic groups. Therefore, the acrylate, which is compatible with hydrophobic substrates, adheres closely to the substrate 20, and the hydrophilic monomers that cure later are more likely to be positioned on the outermost surface. Thus, a thin film of hydrophilic monomer can be applied to the surface of the cured film 10, improving its anti-fogging properties.

[0011] Because acrylate is hydrophobic, when applied to a hydrophobic substrate 20, it can improve the adhesion between the active energy ray curable composition and the substrate. Therefore, it can suppress the peeling of the cured film 10 from the substrate 20. In addition, the high adhesion between the cured film 10 and the substrate 20 can suppress the occurrence of cracks in low-temperature environments. Thus, a highly durable cured film 10 can be formed on the substrate 20.

[0012] The acrylate content is preferably 10% by mass or more and less than 80% by mass relative to the total amount of the active energy ray curable composition. If the acrylate content is less than 10% by mass, sufficient adhesion to the hydrophobic substrate cannot be ensured. On the other hand, if the acrylate content is 80% by mass or more, the proportion of hydrophilic groups decreases relatively, making it impossible to impart sufficient anti-fogging properties to the substrate.

[0013] As the acrylate, monofunctional acrylates such as β-carboxyethyl acrylate, isobornyl acrylate, phenoxydiethylene glycol acrylate, and phenoxyethyl acrylate; bifunctional acrylates such as dipropylene glycol diacrylate, 1,6-hexanediol diacrylate, 3-methyl-1,5-pentanediol diacrylate, and tripropylene glycol diacrylate; trifunctional acrylates such as trimethylolpropane triacrylate, glycerin propoxy triacrylate, and pentaerythritol (tri / tetra)acrylate; and tetrafunctional acrylates such as pentaerythritol alkoxytetraacrylate, pentaerythritol ethoxytetraacrylate, and pentaerythritol (tri / tetra)acrylate can be used. Furthermore, in order to improve the adhesion between the cured film 10 and the substrate 20, it is preferable to use a polyfunctional acrylate with two or more functions as the acrylate.

[0014] The hydrophilic monomer is a radical-reactive material consisting of a resin component. At least a portion of the hydrophilic monomer is arranged on the surface layer of the active energy ray-curable composition when the active energy ray-curable composition is applied to the surface of the substrate 20 (e.g., polycarbonate resin). 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] Therefore, the contact angle between the surface of the molded body 30, which has a hardened film 10 formed on the surface of the substrate 20, and water can be reduced. As a result, moisture diffuses onto the surface of the molded body (hardened film), forming a water film and ensuring the anti-fogging properties of the substrate.

[0016] The content of the hydrophilic monomer is preferably 5% by mass or more and less than 50% by mass with respect to the total amount of the active energy ray-curable composition. When the content of the hydrophilic acrylate is less than 5% by mass with respect to the total amount of the active energy ray-curable composition, a sufficient hydrophilic function cannot be ensured on the surface of the cured film, and clouding of the substrate cannot be prevented. On the other hand, when the content of the hydrophilic acrylate is 90% by mass or more, sufficient adhesion to the hydrophobic substrate cannot be ensured.

[0017] Examples of the hydrophilic monomer include N-isopropylacrylamide, 2-acrylamido-2-methylpropane sulfonic acid, N,N-bis(2-acrylamidoethyl)acrylamide, 3-methyl-1,5-pentanediol diacrylate, N-[tris(3-acrylamidopropoxymethyl)methyl]acrylamide, PEG200 diacrylate, PEG600 diacrylate, and the like. These hydrophilic monomers may be used alone or in combination of two or more.

[0018] In this example, a cured film having an anti-clouding function was described by including a hydrophilic monomer in the active energy ray-curable composition. However, a cured film having a function as a hard coat such as scratch resistance may be formed without including a hydrophilic monomer in the active energy ray-curable composition.

[0019] The initiator is a radical generator that generates highly active radicals by irradiation with ultraviolet rays. These radical species react with resin components such as monomers and / or oligomers through decomposition and the like. This reaction product further reacts with other resin components to cause the reaction to proceed chainwise. Then, the crosslinking reaction proceeds, the molecular weight increases, the radical-reactive material and acrylate are cured, and a cured film is formed.

[0020] The content of the initiator is preferably 1% by mass or more and less than 15% by mass with respect to the total amount of the active energy ray-curable composition. When the content of the initiator is less than 1% by mass, the curing of the active energy ray-curable composition becomes insufficient and curing defects occur. On the other hand, when the content of the initiator is 15% by mass or more, the molecular weight does not increase and the strength of the cured film becomes insufficient.

[0021] As the initiator, for example, 1-hydroxycyclohexyl phenyl ketone, 2-benzyl-2-(dimethylamino)-4'-morpholinobutyrophenone, 2-hydroxy-1-[4-(2-hydroxyethoxy)phenyl]-2-methyl-1-propanone, 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)-2-methylpropan-1-one, etc. can be used. Further, it is preferable to use two or more of these initiators in combination. By using two or more initiators in combination, the curing reaction rate of the active energy ray-curable composition can be improved.

[0022] In addition to the initiator, the active energy ray-curable composition may contain various additives such as antibacterial agents, antifungal agents, antifoaming agents, antioxidants, antistatic agents, dyes, polymerization inhibitors, ultraviolet absorbers, light stabilizers, leveling agents, etc.

[0023] Examples of antibacterial agents include captan, carbendazim, quinomethionate, chlorothalonil, clozolinate, cyprodinil, epoxyconazole, famoxadone, phenalimol, fenbuconazole, fenflam, fenpiclonil, azoxystrobin, venalaxyl, benomyl, vitertanol, fluazinam, fludioxonil, fluorimide, fluquinconazole, flusulfamide, flutolanil, and folpet. Hexachlorobenzene, hexaconazole, ipoconazole, iprodione, kresoximmethyl, mancozeb, maneb, mepanipyrim, mepronil, metconazole, methylam, phthalide, procymidone, propineb, quintozen, technazen, tifluzamide, thiophenate-methyl, thyram, tolclophosmethyl, tolfluanide, triadimephon, triadimenol, triazoxide, and triforine can be used. In addition, inorganic antimicrobial agents such as silver, copper, zinc, tin, lead, and gold can also be used. Furthermore, synthetic antimicrobial agents such as polyhexamethylene hyguanide, hydrochloride, benzethonium chloride, alkylpolyaminoethylglycine, and benzisothiazoline can be used.

[0024] Examples of fungicides that can be used include sodium dehydroacetate, sodium benzoate, sodium pyridinethion-1-oxide, ethyl p-hydroxybenzoate, 1,2-benzisothiazolin-3-one, and their salts.

[0025] Examples of defoaming agents that can be used include fatty acid salts, liquid fatty oil sulfates, higher alcohol sulfates, aliphatic alcohol phosphates, fatty acid amide sulfonates, dibasic fatty acid ester sulfonates, alkylallyl sulfonates, polyoxyethylene alkyl ethers, polyoxyethylene alkylphenol ethers, polyoxyethylene alkyl esters, sorbitan alkyl esters, polyoxyethylene sorbitan alkyl esters, acrylic polymers, vinyl polymers, organopolysiloxanes, and the like.

[0026] Examples of antioxidants that can be used include phenolic antioxidants, phosphorus-based antioxidants, and sulfur-based antioxidants. Examples of phenolic antioxidants that can be used 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 phosphorus-based antioxidants that can be used include tris(2,4-di-tert-butylphenyl) phosphite, diphenyl mono(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).

[0027] Examples of antistatic agents that can be used include cationic antistatic agents having cationic groups such as primary to tertiary amino groups, quaternary ammonium salts, and pyridinium salts; anionic antistatic agents having anionic groups such as sulfonic acid bases, sulfate ester bases, phosphate ester bases, and phosphonic acid bases; amphoteric antistatic agents such as amino acid-based and aminosulfate ester-based agents; nonionic antistatic agents such as amino alcohol-based, glycerin-based, and polyethylene glycol-based agents; and polymeric antistatic agents that are high molecular weight versions of the aforementioned antistatic agents.

[0028] 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, pyrrolopyrazoleazomethine compounds, xanthene compounds, phthalocyanine compounds, benzopyran compounds, indigo compounds, and pyromethene compounds.

[0029] Polymerization inhibitors may be added to prevent the double bond from reacting. Examples of polymerization inhibitors 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.

[0030] Examples of UV absorbers that can be used include octyl methoxycinnamate, octyl dimethoxybenzylidene dioxoimidazolidine propionate, diethylamino hydroxybenzoyl hexyl benzoate, t-butyl methoxydibenzoylmethane, octyl triazone, and 2-ethylhexyl paramethoxycinnamate.

[0031] 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.

[0032] Examples of leveling agents that can be used include silicon-based leveling agents, acrylic-based leveling agents, ester compounds, ketone compounds, and fluorine compounds.

[0033] Using Figure 2, we will explain how to manufacture a molded body 30 in which a cured film 10 formed by curing an active energy ray-curable composition is formed on the surface of a substrate 20. First, the active energy ray-curable composition was filled 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). Ultraviolet light was irradiated onto the active energy ray-curable composition (S4). The active energy ray-curable composition cured on the surface of the substrate 20 to form a cured film 10 (S5). As described above, a molded body 30 in which a cured film 10 formed by curing an active energy ray-curable composition is formed on the surface of the substrate 20 can be manufactured.

[0034] When applying the active energy ray curable composition to the surface of the substrate 20, it may be applied to a part of the surface of the substrate 20 or 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 on the entire surface of the substrate 20.

[0035] In this embodiment, a uniform cured film 10 of 10 μm was formed on the surface of the substrate 20 by applying the active energy ray curable composition to a uniform film thickness of 10 μm. However, the film thickness can be 1 μm to 20 μm, preferably 5 μm or more, and more preferably 10 μm or more. A film thickness of 10 μm or more can further improve the curing reaction rate of the active energy ray curable composition.

[0036] Furthermore, the method for applying the active energy ray-curable composition is not limited to a paint gun; other application methods such as inkjet or dispenser application methods can also be employed.

[0037] As the base material 20, in addition to polycarbonate resin (PC), transparent materials such as hydrophobic synthetic resins like polymethyl methacrylate resin (PMMA) and glass can be used.

[0038] The cured film 10 can be used as an anti-fog coating or a hard coating. The molded body 30 can be used as an outer lens (translucent cover) for vehicle lighting, a camera lens cover, a cover for light sources such as streetlights, a dressing table glass, a window glass, an eyeglass lens, or a cover for the surface of an optical sensor.

[0039] The cured film 10 has a ratio A / B value (hereinafter referred to as "A / B value") of 0.2 or more and less than 0.55, which is the ratio of the peak area (A) due to C=C stretching vibration originating from vinyl groups to the peak area (B) due to C=O stretching vibration originating from ester groups, as detected by FT-IR analysis ATR method (total reflection Fourier transform infrared spectroscopy).

[0040] Figure 3 shows the FT-IR chart detected by measuring the cured film 10 of the present invention using the FT-IR analysis ATR method (Total Reflectance Fourier Transform Infrared Spectroscopy). A Fourier Transform Infrared Spectrophotometer (model: IRXross) manufactured by Shimadzu Corporation was used as the measuring device, and a diamond was used as the prism for the measurement.

[0041] As shown by the solid line in Figure 3, when the cured film 10 of this embodiment was measured by FT-IR analysis using the ATR method, the peak (P1) due to C=C stretching vibration originating from the vinyl group was 1637~1647 cm⁻¹. -1 A peak (P2) appears in the vicinity, and is due to C=O stretching vibrations originating from the ester group, at 1715–1726 cm. -1 It appears nearby.

[0042] The peak area due to the C=C stretching vibration originating from the vinyl group (A) and the peak area due to the C=O stretching vibration originating from the ester group (B) are determined by the peak area in the wavelength band from the short-wavelength side to the long-wavelength side of the full width at half maximum (FMAX) of each peak. In other words, the peak area due to the C=C stretching vibration originating from the vinyl group (A) is determined by the peak area in the wavelength band from the short-wavelength side F1 to the long-wavelength side F2 of the FMAX of peak P1 (the area indicated by dots in Figure 3), and the peak area due to the C=O stretching vibration originating from the ester group (B) is determined by the peak area in the wavelength band from the short-wavelength side F3 to the long-wavelength side F4 of the FMAX of peak P2 (the area indicated by the shaded area in Figure 3). Then, the A / B value is obtained by dividing the peak area due to the C=C stretching vibration originating from the vinyl group (A) by the peak area due to the C=O stretching vibration originating from the ester group (B).

[0043] Figure 4 shows the correlation between the A / B value of the cured film 10 and the peel strength obtained by surface-interface cutting (SAICAS method) between the substrate 20 and the cured film 10. As shown in Figure 4, a negative correlation is observed between the A / B value of the cured film 10 and the peel strength obtained by surface-interface cutting between the substrate 20 and the cured film 10.

[0044] The peel strength of the substrate 20 and the cured film 10 using the surface-interface cutting method (SAICAS method) can be measured under the following analytical conditions. (Analysis conditions) Equipment name: Surface and interface property analysis system (Model: saicas EN type, manufactured by Daipla Wintes Co., Ltd.) Cutting blade: CBN Cutting edge width: 1.0 mm Load cell: Horizontal / Vertical 20N

[0045] Since the cured film 10 has an A / B value of less than 0.55, the peel strength of the surface-interface cutting method between the substrate 20 and the cured film 10 can be made 0.0005 N or higher. In other words, adhesion between the cured film 10 and the substrate 20 can be ensured. The upper limit of the peel strength of the surface-interface cutting method between the substrate 20 and the cured film 10 is 0.003 N or less.

[0046] Furthermore, it is preferable that the A / B value of the cured film 10 be less than 0.38. By setting the A / B value of the cured film 10 to less than 0.38, the peel strength of the surface-interface cutting method between the substrate 20 and the cured film 10 can be made 0.001 N or higher. In other words, the adhesion between the cured film 10 and the substrate 20 can be further improved.

[0047] Next, a method for inspecting an active energy curing type cured film, which is formed by thin-film curing on at least a portion of the surface of a substrate, will be described. By employing the inspection method described below, the adhesion between the surface interface of the cured film 10 and the substrate 20 can be determined.

[0048] First, the cured film 10 is measured using the FT-IR analysis ATR method. Next, the peak area (A) due to C=C stretching vibration originating from vinyl groups and the peak area (B) due to C=O stretching vibration originating from ester groups, which are detected by the FT-IR analysis ATR method, are determined. The peak area (A) due to C=C stretching vibration originating from vinyl groups and the peak area (B) due to C=O stretching vibration originating from ester groups are determined by the area of ​​the peaks in the wavelength band from the short-wavelength side to the long-wavelength side of the full width at half maximum of each peak. Finally, the adhesion between the surface interface of the substrate 20 and the cured film 10 is determined from the ratio A / B (A / B value) of peak area (A) to peak area (B).

[0049] The adhesion between the surface interface of the substrate 20 and the cured film 10 can be determined, for example, by looking at the A / B value, which is less than 0.55. This indicates that the peel strength of the surface interface between the substrate 20 and the cured film 10 by cutting is 0.0005 N or greater, and that sufficient adhesion between the surface interface of the substrate 20 and the cured film 10 is ensured.

[0050] Furthermore, the measurement of the cured film by FT-IR analysis using the ATR method can be performed under the following analytical conditions. (Analysis conditions) Instrument name: Fourier transform infrared spectrophotometer (Model: IRXross, manufactured by Shimadzu Corporation) Prism: Diamond [Examples]

[0051] The present invention will be described in more detail below with reference to examples and comparative examples. However, the present invention is not limited to these examples.

[0052] [Example 1] In a 300 mL separable flask equipped with a stirring blade, β-carboxyethyl acrylate (product code: β-CEA, manufactured by Daicel Ornex Co., Ltd.) was added as the acrylate, and N-isopropylacrylamide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added as the hydrophilic monomer. Next, an initiator was added. By stirring this at room temperature for 30 minutes, an active energy ray curable composition with an acrylate content of 10 wt% and a hydrophilic monomer content of 5 wt% was obtained. This was applied to the surface of a polycarbonate resin (PC) substrate (product name: Yupiron H-3000UR, manufactured by Mitsubishi Engineering Plastics Corporation), and UV curing was performed to obtain a test piece having a cured film of Example 1 with a thickness of 1 μm.

[0053] [Example 2] Phenoxydiethylene glycol acrylate (product name: EBECRYL 110, manufactured by Daicel Ornex Co., Ltd.) and an initiator were added as the acrylate. By stirring this mixture at room temperature for 30 minutes, an active energy ray curable composition with an acrylate content of 20 wt% was obtained. This was applied to the surface of a PC substrate (product name: Yupiron H-3000UR, manufactured by Mitsubishi Engineering Plastics Corporation) and UV cured to obtain a test piece having a cured film of Example 2 with a thickness of 2 μm.

[0054] [Example 3] Phenoxydiethylene glycol acrylate (product name: EBECRYL 110, manufactured by Daicel Ornex Co., Ltd.) and an initiator were added to a 300 mL separable flask equipped with a stirring blade. By stirring this mixture at room temperature for 30 minutes, an active energy ray curable composition with an acrylate content of 30 wt% was obtained. This was applied to the surface of a PC substrate (product name: L-1250Y, manufactured by Teijin Limited) and UV cured to obtain a test piece having a cured film of Example 3 with a thickness of 2 μm.

[0055] [Example 4] In a 300 mL separable flask equipped with a stirring blade, phenoxyethyl acrylate (product code: EBECRYL 114, manufactured by Daicel Ornex Corporation) was added as the acrylate, and N,N-bis(2-acrylamidoethyl)acrylamide (product name: FOM-03007, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added as the hydrophilic monomer. Next, an initiator was added. By stirring this at room temperature for 30 minutes, an active energy ray curable composition with an acrylate content of 30 wt% and a hydrophilic monomer content of 15 wt% was obtained. This was applied to the surface of a PC substrate (product name: Yupiron H-2000UR, manufactured by Mitsubishi Engineering Plastics Corporation), and UV curing was performed to obtain a test piece having a cured film of Example 4 with a thickness of 3 μm.

[0056] [Example 5] In a 300 mL separable flask equipped with a stirring blade, 3-methyl-1,5-pentanediol diacrylate (product code: EBECRYL MPDDA, manufactured by Daicel Ornex Corporation) was added as the acrylate, and N,N-bis(2-acrylamidoethyl)acrylamide (product name: FOM-03007, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added as the hydrophilic monomer. Next, an initiator was added. By stirring this at room temperature for 30 minutes, an active energy ray curable composition with an acrylate content of 35 wt% and a hydrophilic monomer content of 20 wt% was obtained. This was applied to the surface of a PC substrate (product name: L-1250Y, manufactured by Teijin Limited), and UV curing was performed to obtain a test piece having a cured film of Example 5 with a thickness of 7 μm.

[0057] [Example 6] In a 300 mL separable flask equipped with a stirring blade, 1,6-hexanediol diacrylate (product name: HDDA, manufactured by Daicel Ornex Co., Ltd.) as the acrylate and an initiator were added. By stirring this mixture at room temperature for 30 minutes, an active energy ray curable composition with an acrylate content of 40 wt% was obtained. This was applied to the surface of a PC substrate (product name: G-3415, manufactured by Teijin Limited) and UV cured to obtain a test piece having a cured film of Example 6 with a thickness of 8 μm.

[0058] [Example 7] In a 300 mL separable flask equipped with a stirring blade, tripropylene glycol diacrylate (product code: TPGDA, manufactured by Daicel Ornex Corporation) was added as the acrylate, and 3-methyl-1,5-pentanediol diacrylate (product name: EBECRYL MPDDA, manufactured by Daicel Ornex Corporation) was added as the hydrophilic monomer. Next, an initiator was added. By stirring this at room temperature for 30 minutes, an active energy ray curable composition with an acrylate content of 40 wt% and a hydrophilic monomer content of 30 wt% was obtained. This was applied to the surface of a PC substrate (product name: Yupiron H-2000UR, manufactured by Mitsubishi Engineering Plastics Corporation), and UV curing was performed to obtain a test piece having a cured film of Example 7 with a thickness of 10 μm.

[0059] [Example 8] Glycerin propoxytriacrylate (product name: OTA 480, manufactured by Daicel Ornex Co., Ltd.) as the acrylate and an initiator were added to a 300 mL separable flask equipped with a stirring blade. By stirring this at room temperature for 30 minutes, an active energy ray curable composition with an acrylate content of 40 wt% was obtained. This was applied to the surface of a PC substrate (product name: L-1250Y, manufactured by Teijin Limited) and UV cured to obtain a test piece having a cured film of Example 8 with a thickness of 10 μm.

[0060] [Example 9] Pentaerythritol (tri / tetra)acrylate (product name: PETIA, manufactured by Daicel Ornex Co., Ltd.) and an initiator were added to a 300 mL separable flask equipped with a stirring blade. By stirring this mixture at room temperature for 30 minutes, an active energy ray curable composition with an acrylate content of 45 wt% was obtained. This was applied to the surface of a PC substrate (product name: Yupiron H-3000UR, manufactured by Mitsubishi Engineering Plastics Corporation) and UV cured to obtain a test piece having a cured film of Example 9 with a thickness of 11 μm.

[0061] [Example 10] In a 300 mL separable flask equipped with a stirring blade, trimethylolpropane triacrylate (product code: TMPTA, manufactured by Daicel Ornex Corporation) was added as the acrylate, and N-[tris(3-acrylamidepropoxymethyl)methyl]acrylamide (product name: FOM03006, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added as the hydrophilic monomer. Next, an initiator was added. By stirring this at room temperature for 30 minutes, an active energy ray curable composition with an acrylate content of 50 wt% and a hydrophilic monomer content of 30 wt% was obtained. This was applied to the surface of a PC substrate (product name: Yupiron H-3000UR, manufactured by Mitsubishi Engineering Plastics Corporation), and UV curing was performed to obtain a test piece having a cured film of Example 10 with a thickness of 10 μm.

[0062] [Example 11] Pentaerythritol (tri / tetra)acrylate (product name: PETIA, manufactured by Daicel Ornex Co., Ltd.) and an initiator were added to a 300 mL separable flask equipped with a stirring blade. By stirring this mixture at room temperature for 30 minutes, an active energy ray curable composition with an acrylate content of 50 wt% was obtained. This was applied to the surface of a PC substrate (product name: L-1250Y, manufactured by Teijin Limited) and UV cured to obtain a test piece having a cured film of Example 11 with a thickness of 12 μm.

[0063] [Example 12] In a 300 mL separable flask equipped with a stirring blade, pentaerythritol alkoxytetraacrylate (product code: EBECRYL 40, manufactured by Daicel Ornex Corporation) was added as the acrylate, and PEG600 diacrylate (product name: EBECRYL 11, manufactured by Daicel Ornex Corporation) was added as the hydrophilic monomer. Next, an initiator was added. By stirring this at room temperature for 30 minutes, an active energy ray curable composition with an acrylate content of 55 wt% and a hydrophilic monomer content of 40 wt% was obtained. This was applied to the surface of a PC substrate (product name: Yupiron H-2000UR, manufactured by Mitsubishi Engineering Plastics Corporation), and UV curing was performed to obtain a test piece having a cured film of Example 12 with a thickness of 15 μm.

[0064] [Example 13] Pentaerythritol (tri / tetra)acrylate (product name: PETIA, manufactured by Daicel Ornex Co., Ltd.) and an initiator were added to a 300 mL separable flask equipped with a stirring blade. By stirring this mixture at room temperature for 30 minutes, an active energy ray curable composition with an acrylate content of 55 wt% was obtained. This was applied to the surface of a PC substrate (product name: G-3415, manufactured by Teijin Limited) and UV cured to obtain a test piece having a cured film of Example 13 with a thickness of 15 μm.

[0065] [Example 14] Pentaerythritol ethoxytetraacrylate (product code: EBECRYL 50, manufactured by Daicel Ornex Co., Ltd.) as the acrylate and PEG200 diacrylate (product name: EBECRYL 11, manufactured by Daicel Ornex Co., Ltd.) as the hydrophilic monomer were added to a 300 mL separable flask equipped with a stirring blade. Next, an initiator was added. By stirring this at room temperature for 30 minutes, an active energy ray curable composition with an acrylate content of 60 wt% and a hydrophilic monomer content of 50 wt% was obtained. This was applied to the surface of a polymethyl methacrylate resin (PMMA) substrate (product name: Acrypet TN100, manufactured by Mitsubishi Engineering Plastics Corporation) and UV curing was performed to obtain a test piece having a cured film of Example 14 with a thickness of 15 μm.

[0066] [Example 15] Pentaerythritol ethoxytetraacrylate (product code: EBECRYL 50, manufactured by Daicel Ornex Co., Ltd.) as the acrylate and an initiator were added to a 300 mL separable flask equipped with a stirring blade. By stirring this mixture at room temperature for 30 minutes, an active energy ray curable composition with an acrylate content of 60 wt% was obtained. This was applied to the surface of a PMMA substrate (product name: Acrypet VHS, manufactured by Mitsubishi Engineering Plastics Corporation) and UV cured to obtain a test piece having a cured film of Example 15 with a thickness of 17 μm.

[0067] [Example 16] Pentaerythritol alkoxytetraacrylate (product code: EBECRYL 40, manufactured by Daicel Ornex Co., Ltd.) as the acrylate and an initiator were added to a 300 mL separable flask equipped with a stirring blade. By stirring this at room temperature for 30 minutes, an active energy ray curable composition with an acrylate content of 60 wt% was obtained. This was applied to the surface of a PC substrate (product name: G-3415, manufactured by Teijin Limited) and UV cured to obtain a test piece having a cured film of Example 16 with a thickness of 18 μm.

[0068] [Example 17] Pentaerythritol ethoxytetraacrylate (product code: EBECRYL 50, manufactured by Daicel Ornex Co., Ltd.) as the acrylate and an initiator were added to a 300 mL separable flask equipped with a stirring blade. By stirring this at room temperature for 30 minutes, an active energy ray curable composition with an acrylate content of 65 wt% was obtained. This was applied to the surface of a PC substrate (product name: Yupiron H-2000UR, manufactured by Mitsubishi Engineering Plastics Corporation) and UV cured to obtain a test piece having a cured film of Example 17 with a thickness of 19 μm.

[0069] [Comparative Example 1] In a 300 mL separable flask equipped with a stirring blade, 5 wt% of β-carboxyethyl acrylate (product code: β-CEA, manufactured by Daicel Ornex Corporation) and 5 wt% of N-isopropylacrylamide (manufactured by Fujifilm Wako Pure Chemical Industries Ltd.) were added as the acrylate and hydrophilic monomer, respectively. By stirring this mixture at room temperature for 30 minutes, an active energy ray curable composition with an acrylate content of 5 wt% and a hydrophilic monomer content of 5 wt% was obtained. This was applied to the surface of a PC substrate and cured with UV light to obtain a test piece having a cured film of Comparative Example 1 with a film thickness of 0.8 μm.

[0070] [Comparative Example 2] In a 300 mL separable flask equipped with a stirring blade, 20 wt% polyester polyol (product name: Polylight OD-X-2420, manufactured by DIC Corporation) was added as the main component, and 10 wt% polyethylene glycol diacrylate (product code: P2708, manufactured by Tokyo Chemical Industry Co., Ltd.) was added as a curing agent. Next, 70 wt% methyl isobutyl ketone (product name: WM44-L70G, manufactured by Asahi Kasei Corporation) was added as the solvent. By stirring this at room temperature for 30 minutes, a thermosetting composition of 100 wt% was obtained. This was applied to the surface of a substrate and cured by heating at 80 degrees Celsius for 40 minutes, resulting in a test piece having a cured film of Comparative Example 2 with a film thickness of 15 μm.

[0071] (Measurement of A / B values) The cured films of Examples 1-17 or Comparative Examples 1-3 were measured using FT-IR analysis (ATR method) to obtain FT-IR charts. Next, the ratio A / B of the peak area due to C=C stretching vibrations originating from vinyl groups (A) and the peak area due to C=O stretching vibrations originating from ester groups (B), as detected by FT-IR analysis (ATR method), was determined. The peak areas due to C=C stretching vibrations originating from vinyl groups (A) and C=O stretching vibrations originating from ester groups (B) were determined by the peak area in the wavelength band from the short-wavelength side to the long-wavelength side of the full width at half maximum of each peak. A Fourier transform infrared spectrophotometer (model: IRXross) manufactured by Shimadzu Corporation was used as the measuring instrument, and a diamond prism was used for the measurements. Figure 5 shows the A / B values ​​for Examples 1-17 and Comparative Examples 1-3 together.

[0072] (Evaluation of adhesion) Under the analytical conditions described below, the adhesion between the substrate and the cured film was evaluated on a five-point scale from A to E by measuring the peel strength of the cured films of Examples 1 to 17 or Comparative Examples 1 to 3 using the surface-interface cutting method (SAICAS method). The evaluation was based on the following criteria: A for a peel strength of 0.0018 N or higher, B for a peel strength of 0.0015 N or higher and less than 0.0018 N, C for a peel strength of 0.001 N or higher and less than 0.0015 N, D for a peel strength of 0.0005 N or higher and less than 0.001 N, and E for a peel strength of less than 0.0005 N. Figure 5 summarizes the evaluation results of the adhesion between the substrate and the cured film of Examples 1 to 17 and Comparative Examples 1 to 3. (Analysis conditions) Equipment name: Surface and interface property analysis system (Model: saicas EN type, manufactured by Daipla Wintes Co., Ltd.) Cutting blade: CBN Cutting edge width: 1.0 mm Load cell: Horizontal / Vertical 20N

[0073] (Evaluation of water stains) The haze values ​​of the surfaces of the cured films of Examples 1-17 and Comparative Examples 1-3 were measured. Next, 20 mL of 50-degree Celsius hot water was dropped onto the surface of the cured films of Examples 1-19 and Comparative Example 1, and the process of air drying was repeated 10 times. After that, the haze values ​​of the surfaces of the cured films of Examples 1-19 and Comparative Example 1 were measured again. The water droplet marks were then evaluated on a 5-point scale from A to E by determining the percentage change in haze values ​​before and after the above process. The evaluation was as follows: A if the percentage change in haze value was less than 1.0%, B if the percentage change in haze value was 1.0% or more and less than 2.0%, C if the percentage change in haze value was 2.0% or more and less than 4.0%, D if the percentage change in haze value was 4.0% or more and less than 7.0%, and E if the percentage change in haze value was 7.0% or more. Figure 5 shows a summary of the evaluation results of the water droplet marks of Examples 1-17 and Comparative Examples 1-3.

[0074] (Evaluation of abrasion resistance) The abrasion resistance of the cured films of Examples 1-17 and Comparative Examples 1-3 was evaluated on a five-point scale from A to E by measuring the rate of change in diffuse transmittance using a method compliant with the abrasion resistance test (reciprocating test piece method) of the general coating film testing method (JIS K 5600-5-10). The evaluation was as follows: A for a rate of change in diffuse transmittance of less than 1.0%, B for a rate of change in diffuse transmittance of 1.0% or more and less than 2.0%, C for a rate of change in diffuse transmittance of 2.0% or more and less than 4.0%, D for a rate of change in diffuse transmittance of 4.0% or more and less than 7.0%, and E for a rate of change in diffuse transmittance of 7.0% or more. Figure 5 shows a summary of the abrasion resistance evaluation results for Examples 1-17 and Comparative Examples 1-3.

[0075] (Evaluation of hardness) The scratch hardness of the cured films of Examples 1 to 17 and Comparative Examples 1 to 3 was evaluated on a five-point scale from A to E by measuring the scratch hardness (pencil method) of the mechanical properties of coating films in accordance with the general testing method for coating films (JIS K 5600-5-4). The evaluation was as follows: A was given if the pencil hardness scale was H or higher, B if it was F, C if it was HB, D if it was B, and E if it was 2B or lower. Figure 5 shows a summary of the hardness evaluation results for Examples 1 to 17 and Comparative Examples 1 to 3.

[0076] Figure 5 shows that the cured films of the test specimens in Examples 1 to 17 have an A / B value of 0.55 or less, indicating a peel strength of 0.005 N or higher in the adhesion evaluation. Therefore, it is clear that adhesion between the substrate and the cured film is ensured. Furthermore, the test specimens of Examples 1, 4, 5, 7, 10, 12, and 14, which function as anti-fogging coatings, show a change in Haze value of less than 7.0% in the water droplet evaluation, indicating that the formation of water droplets is suppressed. In addition, the test specimens of Examples 2, 3, 6, 8, 9, 11, 13, and 15 to 17, which function as hard coatings, show excellent abrasion resistance, as the change in diffusion transmittance is less than 4.0% in the abrasion resistance evaluation. Moreover, the test specimens of Examples 1 to 17 have a pencil hardness scale of B or higher in the hardness evaluation, indicating that hardness is ensured.

[0077] The cured films of the test specimens in Examples 7-17 have a film thickness of 10 μm or more, indicating a high curing reaction rate. Therefore, the cured films of the test specimens in Examples 7-17 have an A / B value of 0.41 or less, and the peel strength in the adhesion evaluation is 0.001 N or more. Thus, it is clear that the adhesion between the substrate and the cured film is further improved. Furthermore, the test specimens in Examples 8, 9, 11, 13, and 15-17, which function as hardcodes, have a change rate of less than 2.0% in the abrasion evaluation, indicating superior abrasion resistance. In addition, the test specimens in Examples 7-17 have a pencil hardness scale of F or higher in the hardness evaluation, indicating that higher hardness is ensured.

[0078] The cured films of the test specimens in Examples 11-17 have a film thickness of 12 μm or more, indicating a higher curing reaction rate. Therefore, the cured films of the test specimens in Examples 11-17 have an A / B value of 0.36 or less, and a peel strength of 0.0015 N or more in the adhesion evaluation. Thus, it is clear that the adhesion between the substrate and the cured film is improved. Furthermore, the test specimens of Examples 12 and 14, which have the function of an anti-fogging coating, show a change in the Haze value of less than 1.0% in the evaluation of water droplet marks, indicating that the formation of water droplet marks is more suppressed. In addition, the test specimens of Examples 11, 13, and 15-17, which have the function of a hard coat, show superior abrasion resistance, as the change in the diffusion transmittance of less than 1.0% in the evaluation of abrasion resistance. Furthermore, the test specimens of Examples 11-17 have a pencil hardness scale of H or higher in the hardness evaluation, indicating that higher hardness is ensured.

[0079] The cured films of the test specimens in Examples 12-17 have a film thickness of 15 μm or more, indicating an even higher curing reaction rate. Therefore, the cured films of the test specimens in Examples 12-17 have an A / B value of 0.34 or less, and a peel strength of 0.0018 N or more in the adhesion evaluation. Thus, it is clear that the adhesion between the substrate and the cured film has been further improved.

[0080] In contrast, Comparative Example 1, which has a cured film with an A / B value of 0.56, has a peel strength of 0.0005 N or less, clearly indicating that adhesion between the substrate and the cured film is not ensured. Furthermore, in the evaluation of water droplet marks, the change rate of the Haze value is 7.0% or more, clearly indicating that the formation of water droplet marks cannot be suppressed. Moreover, in the evaluation of hardness, the pencil hardness scale is 2B or less, clearly indicating that hardness is not ensured.

[0081] Similarly, in Comparative Example 2, which is a thermosetting composition, the peel strength is 0.0005 N or less, clearly indicating that adhesion between the substrate and the cured film is not ensured. Furthermore, in the evaluation of water droplet marks, the change rate of the haze value is 7.0% or more, clearly indicating that the formation of water droplet marks is not suppressed. In addition, in the evaluation of abrasion resistance, the change rate of the diffusion transmittance is 7.0% or more, clearly indicating that the abrasion resistance is insufficient. Moreover, in the evaluation of hardness, the pencil hardness scale is 2B or less, clearly indicating that hardness is not ensured.

[0082] As described above, the cured film of the present invention and the lens having the cured film ensure good adhesion between the substrate and the cured film. [Explanation of symbols]

[0083] 10 Cured film 20 Base material 30 molded bodies

Claims

1. An active energy curable film that covers at least a portion of the surface of a substrate, The cured film has a ratio A / B of 0.2 or more and less than 0.55 between the peak area (A) due to C=C stretching vibration originating from vinyl groups and the peak area (B) due to C=O stretching vibration originating from ester groups, as detected by FT-IR analysis ATR method. The aforementioned peak area (A) and peak area (B) are determined by the area of ​​the peak in the wavelength band from the short-wavelength side to the long-wavelength side of the full width at half maximum of each peak. A cured film having a peel strength of 0.0005 N or more when measured by surface-interface cutting between the substrate and the cured film.

2. The value of A / B is less than 0.41, The cured film according to claim 1, wherein the peel strength of the substrate and the cured film by surface-interface cutting is 0.001 N or more.

3. The cured film according to claim 1, wherein the thickness of the cured film is 5 μm or more and 20 μm or less.

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

5. A lens for a vehicle lamp having the cured film described in claim 3.

6. A method for inspecting an active energy curing type cured film that has been thinly cured on at least a portion of the surface of a substrate, The peak area (A) due to C=C stretching vibrations originating from vinyl groups and the peak area (B) due to C=O stretching vibrations originating from ester groups, which are detected by measuring the cured film using the FT-IR analysis ATR method, are determined by the area of ​​the peaks in the wavelength band from the short-wavelength side to the long-wavelength side of the full width at half maximum of each peak. A method for inspecting a cured film, wherein the adhesion between the surface interface of the substrate and the cured film is determined from the ratio A / B of the peak area (A) and the peak area (B).

Images