Curable composition and film containing the cured layer

Abstract

To provide a curable composition capable of forming a cured layer improved in finger slipperiness.SOLUTION: The present invention relates to the curable composition containing the following components: (1) a perfluoropolyether group-containing acrylate monomer having a number average molecular weight of 3,000 or more and 7,500 or less; (2) a fluorine group-containing acrylate monomer having a number average molecular weight of 500 or more and less than 3,000; (3) a polyfunctional acrylate monomer (excluding the acrylate monomers (1) and (2)); (4) a photoinitiator; and (5) an organic solvent.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to novel curable compositions. [Background technology]

[0002] For example, touch panels that allow users to operate the screen by touching it with their fingers on a screen with a touch sensor function (touch input function) are becoming more common in displays of smartphones, tablet devices, PC monitors, ticket vending machines, information displays, in-vehicle operation panels, digital cameras, multifunction printers (monitors), portable game devices, bank ATMs, digital audio players, etc. These displays have higher resolutions and can display clearer images, but scratches and dirt on the screen surface can make the image difficult to see. Therefore, protective films are placed on the screen surface to maintain clear images for a long period of time.

[0003] For the purposes mentioned above, protective films are required to have transparency, abrasion resistance, stain resistance, water and oil repellency, and fingerprint wipeability, but protective films that also have other functions such as anti-reflective properties and antibacterial properties are also being developed.

[0004] For example, a resin composition for forming a low refractive index layer is known, which is used to form the low refractive index layer of an antireflection film having the low refractive index layer, and is characterized by containing a polyfunctional monomer that is at least one type of polyfunctional acrylate monomer or methacrylate monomer having 3 to 8 functional groups, and a bifunctional monomer that is a bifunctional acrylate monomer or methacrylate monomer represented by a specific general formula (Patent Document 1).

[0005] As a film for a touch panel, for example, a hard coat film has been proposed which has a hard coat layer on a substrate, the hard coat layer containing a cured product of an ionizing radiation-curable composition which contains an antifouling agent having an ionizing radiation-curable functional group and a binder resin component having an ionizing radiation-curable functional group, the hard coat layer being substantially free of particles, and which satisfies specific conditions (Patent Document 2).

[0006] Furthermore, for example, a film is known that has frictional properties in which, when the relative dynamic friction coefficient μ is measured by changing the moving speed v (mm / s) of a contact, the slope a of the line obtained by linear fitting, where log(v), which is the common logarithm of the moving speed, is on the horizontal axis and μ is on the vertical axis, is 0.01 or more and the intercept b is 0.6 or less (Patent Document 3). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-63061 [Patent Document 2] Japanese Patent Application Publication No. 2018-202697 [Patent Document 3] International Publication WO2019 / 82664 Summary of the Invention [Problem to be solved by the invention]

[0008] However, although these films have certain properties and can be used as protective films, there is still room for improvement for use in touch panels, namely, the problem of finger slipperiness.

[0009] Recently, with the advancement of functionality and miniaturization of devices, there has been a need for more precise operation of touch panels, which requires fine finger movements on the touch panel. In this case, if the touch panel surface gets caught on the finger surface, smooth finger movement becomes impossible, making it difficult to operate quickly and leading to operational errors.

[0010] In this respect, the finger sliding properties of conventional protective films or hard coats need to be further improved.

[0011] Therefore, a primary object of the present invention is to provide a curable composition capable of forming a cured layer having improved finger sliding properties. [Means for solving the problem]

[0012] As a result of extensive research into the problems of the prior art, the present inventors have discovered that the above object can be achieved by employing a composition having a specific composition, and have thus completed the present invention.

[0013] That is, the present invention relates to the following curable composition and a film comprising a cured layer thereof. 1. The following ingredients: (1) a perfluoropolyether group-containing acrylate monomer having a number average molecular weight of 3,000 or more and 7,500 or less; (2) a fluorine group-containing acrylate monomer having a number average molecular weight of 500 or more and less than 3,000; (3) Polyfunctional acrylate monomers (excluding the acrylate monomers (1) and (2) above), (4) Photoinitiators and (5) Organic solvents A curable composition comprising: 2. The curable composition according to item 1, wherein the solid content of the perfluoropolyether group-containing acrylate monomer is 10 to 30% by weight. 3. The curable composition according to item 1 or 2, wherein the fluorine group-containing acrylate monomer is contained in an amount of 150 parts by weight or more per 100 parts by weight of the perfluoropolyether group-containing acrylate monomer. 4. The curable composition according to any one of items 1 to 3, wherein the organic solvent comprises at least one of a ketone-based solvent, an ester-based solvent, an alcohol-based solvent, and an amide-based solvent. 5. A film in which a cured layer of the curable composition according to any one of items 1 to 4 is disposed as the outermost layer. 6. The film according to claim 5, wherein the thickness of the cured layer is 0.01 to 0.1 μm. 7. An optical product comprising the film according to item 5 or 6 laminated on a substrate. 8. The optical product according to item 7, wherein the substrate is a display screen that serves as a touch sensor portion of a touch panel display. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a curable composition that can form a cured layer that has particularly improved finger sliding properties.

[0015] In particular, the curable composition of the present invention uses a perfluoropolyether group-containing (meth)acrylate monomer (first component) having a relatively large molecular weight in combination with a fluorine group-containing (meth)acrylate monomer (second component) having a relatively small molecular weight. This allows the first component, which is soluble only in fluorine-based solvents alone, to be effectively dissolved in a general-purpose solvent such as MEK, resulting in the formation of a cured layer with excellent finger slipperiness. In particular, since this cured layer is made of a fluorine-based material, it is believed that its excellent water repellency, oil repellency (oil-repellent ink property), etc. also contributes to the improved finger slipperiness. In other words, even if sweat or sebum is present on the hands, the cured layer can repel them, which is thought to result in excellent finger slipperiness on the surface of the cured layer.

[0016] Furthermore, since the curable composition of the present invention is provided in the form of a solution dissolved in a general-purpose solvent as described above, it is possible to form a thin coating film, thereby providing a cured layer consisting of a thin film, particularly a film having a thickness of 0.1 μm or less. This makes it possible to provide a cured layer or film having an outermost surface with the desired finger-slip properties, even if the underlying layer has an optically functional layer such as a refractive index control layer or an antireflection layer, without impairing the function of the underlying layer. In other words, the cured layer of the present invention can be suitably used as a film for protecting the surface of an optically functional layer.

[0017] The curable composition of the present invention having such characteristics can be suitably used, for example, as a protective layer or protective film in optical products, and is particularly suitable as a material for protecting the screen (outermost surface) of a touch panel that can be operated with fingers. DETAILED DESCRIPTION OF THE INVENTION

[0018] 1.Curable composition The curable composition of the present invention (the composition of the present invention) comprises the following components: (1) a perfluoropolyether group-containing (meth)acrylate monomer (first component) having a number average molecular weight of 3,000 or more and 7,500 or less; (2) a fluorine group-containing (meth)acrylate monomer (second component) having a number average molecular weight of 500 or more and less than 3,000; (3) a polyfunctional (meth)acrylate monomer (excluding the (meth)acrylate monomers (1) and (2) above) (third component), (4) a photoinitiator (fourth component) and (5) Organic solvent (fifth component) The present invention is characterized by comprising:

[0019] In the present invention, unless otherwise specified, an acryloyl group or a methacryloyl group is collectively referred to as a "(meth)acryloyl group." An acryloyloxy group or a methacryloyloxy group is collectively referred to as a "(meth)acryloyloxy group." Furthermore, an acrylate or a methacrylate is collectively referred to as a "(meth)acrylate," and an acrylic acid or a methacrylic acid is collectively referred to as a "(meth)acrylic acid."

[0020] A. Components of the Composition of the Present Invention First component The perfluoropolyether group-containing (meth)acrylate monomer, which is the first component, has a number average molecular weight of 3000 or more and 7500 or less (preferably 4000 or more and 7000 or less). By using a monomer with such a relatively large molecular weight, high finger smoothness can be obtained.

[0021] In the present invention, for example, a compound represented by the general formula A-PFPE-B (wherein PFPE represents a perfluoropolyether group, and one or both of A and B are (meth)acryloyl group-containing organic functional groups, and when A or B is not a (meth)acryloyl group-containing organic functional group, it is an alkyl group having 10 or less carbon atoms in which some or all of the hydrogen atoms may be substituted with fluorine atoms) can be used as the first component.

[0022] The perfluoropolyether group (PFPE) is -(C x F 2x O) m -(x, m are integers other than 0) is a basic unit, and it has a structure in which multiple units are linked together. When m is 2 or more, each (C x F 2x O) may be the same as or different from each other. That is, PFPE may have a structure consisting of a single repeat of a unit, or may have a structure consisting of a combination of two or more different units. x F 2x O) may have a straight or branched carbon chain.

[0023] Become a unit-(C x F 2x Examples of - include, but are not limited to, CF2O, CF2CF2O, CF2CF2CF2O, CF2CF2CF2CF2O, CF(CF3)CF2O, CF(CF3)CF(CF3)CF2O, CF2CF(CF3)CF2CF2O, etc. In particular, in the present invention, -(CF2CF2O) m -(CF2O) n - (where m and n are integers other than 0) can be preferably employed. In this case, the m and n can be within the ranges of, for example, about 10≦m≦40 and about 10≦n≦40, but are not limited to the above ranges of m and n as long as they are within the above molecular weight range.

[0024] The (meth)acryloyl group-containing organic functional groups A and B are not limited, and may be any organic functional group having a (meth)acryloyl group or a (meth)acryloyloxy group at the terminal.

[0025] For example, the (meth)acryloyl group-containing organic functional groups A and B that do not have a urethane bond include -R 2 -R 1 (R 1 is a (meth)acryloyl group or a (meth)acryloyloxy group, and R 2 is an alkylene group having 10 or less carbon atoms in which some or all of the hydrogen atoms may be substituted with fluorine atoms.) Therefore, for example, as A or B, an organic functional group represented by the following formula can be suitably used. 1 , -CH2-R 1 , -CF2CH2-R 1 , -CF2CF2-R 1 ,CF2CH2CH2-R 1 , -CH2CF2-R 1 , -CH2CH2-R 1 Examples include:

[0026] Further, for example, the (meth)acryloyl group-containing organic functional groups A and B having a urethane bond include: (i)-R 2 -OCONH-R1 (R 1 is a (meth)acryloyl group or a (meth)acryloyloxy group, and R 2 is an alkylene group having 10 or less carbon atoms in which some or all of the hydrogen atoms may be substituted with fluorine atoms), or (ii)-R 2 -OCONH-R 3 -(R 1 ) n (R 1 is a (meth)acryloyl group or a (meth)acryloyloxy group, and R 2 is an alkylene group having 10 or less carbon atoms in which some or all of the hydrogen atoms may be substituted with fluorine atoms, and R 3 is a hydrocarbon group having 1 to 10 carbon atoms which may have a branched chain, and n is an integer of 1 or 2. Therefore, for example, specific examples of A or B include organic functional groups represented by -CH2-OCONH-R 1 , -CF2-OCONH-R 1 , -CF2CH2-OCONH-R 1 , -CF2CF2-OCONH-R 1 ,CF2CH2CH2-OCONH-R 1 , -CH2CF2-OCONH-R 1 , -CH2CH2-OCONH-R 1 , -CF2CH2-OCONH-CH2CH2-R 1 , -CF2CH2-OCONH-C(CH3)-(R 1 )2 and the like can be exemplified.

[0027] Furthermore, when A or B is not a (meth)acryloyl group-containing organic functional group, A or B is preferably an alkyl group having 10 or less carbon atoms in which some or all of the hydrogen atoms may be substituted with fluorine atoms. Examples of such organic groups include CF3-, CF3CF2-, CF3CH2-, CH3-, and CH3CF2-.

[0028] As the first component itself, known or commercially available compounds can be used, and compounds synthesized by known production methods can also be used.

[0029] As a commercially available product, for example, a product named "Fomblin MD40" (manufactured by Solvay Specialty Polymers, Inc.) can be used.

[0030] In addition, as a method for bonding (meth)acryloyl groups to both ends or one end of a perfluoropolyether group, the first component can be suitably prepared, for example, by reacting a compound (starting compound) having a perfluoropolyether group as the main chain and having OH groups as both end groups or one end group with an isocyanate group-containing (meth)acrylate compound.

[0031] The starting compounds can be known or commercially available. Commercially available products include, for example, hydroxyl group-containing perfluoropolyether compounds with the product names "ZMF-402," "FLUOROLINK D-6000," and "Fomblin D2" (all manufactured by Solvay Specialty Polymers Co., Ltd.). "ZMF-402" is represented by the following general formula (1). "FLUOROLINK D-6000" is represented by the following general formula (2). [ka] [ka]

[0032] In the starting compound, the terminal not having an OH group may be an alkyl group having 10 or less carbon atoms in which some or all of the hydrogen atoms may be substituted with fluorine atoms, such as CF3-, CH3-, CF3CH2-, CF3CF2-, and CH3CH2-.

[0033] The isocyanate group-containing (meth)acrylate compound may be any compound having a (meth)acryloyl group or a (meth)acryloyloxy group and an isocyanate group, and known or commercially available compounds may be used. Suitable commercially available compounds include Karenz AOI, Karenz BEI, and Karenz MOI (all manufactured by Showa Denko K.K.).

[0034] The production conditions are not particularly limited, but the production can be carried out, for example, by a method including a step of reacting a starting compound and an isocyanate group-containing (meth)acrylate compound in a solvent at a temperature of 20 to 70°C (reaction step), and a step of recovering the first component (target product) from the reaction product liquid (recovery step).

[0035] In the reaction step, the charging ratio between the starting compound and the isocyanate group-containing (meth)acrylate compound is not particularly limited, but can be appropriately set within the range of, for example, about 1:1.1 to 1:3.5 in molar ratio.

[0036] Furthermore, in the reaction step, a liquid phase reaction is carried out using a solvent, and it is preferable to use a fluorine-based solvent as the solvent. For example, a hydrofluoroether-based solvent can be suitably used as the fluorine-based solvent. Known or commercially available solvents can also be used as such solvents. For example, 1,3-bis(trifluoromethyl)benzene can be used. Furthermore, commercially available products such as "Novec HFE-7200" (a product of 3M) and "Novec HFE-7300" (a product of 3M) can be suitably used.

[0037] The reaction step can be carried out in the presence of a catalyst, if necessary. As the catalyst, an alkaline catalyst can be suitably used, and among them, at least one organic alkaline catalyst selected from triethylamine, tributylamine, pyridine, and 1,4-diazabicyclo[2.2.2]octane is particularly preferred.

[0038] In the recovery step, the method is not particularly limited as long as it allows the recovery (isolation) of the target first component. For example, a method can be used in which an alcohol (methanol, ethanol, etc.) is added to the reaction product liquid, followed by layer separation and then removal of the supernatant liquid (the upper layer of the reaction product liquid). That is, the first component generally precipitates in the reaction product liquid, and can be purified and separated by removing the supernatant liquid. The first component can be obtained in a higher yield by repeating the series of steps of adding an alcohol and removing the supernatant liquid multiple times. In this case, the first component can also be recovered as a solid by reducing the pressure, drying, etc., as necessary.

[0039] The method for measuring the number average molecular weight in the present invention is not particularly limited, and can be performed by measurement in polystyrene equivalent using gel permeation chromatography, or measurement by structural analysis using nuclear magnetic resonance spectroscopy.

[0040] The solid content of the first component in the composition of the present invention is not limited, but is usually about 10 to 30 mass %, and preferably 15 to 25 mass %, which makes it possible to more reliably form a coating film with excellent finger sliding properties, etc.

[0041] Second component The fluorine group-containing (meth)acrylate monomer that is the second component has a physical property of having a number average molecular weight of 500 or more and less than 3,000 (preferably 1,000 or more and 2,000 or less).

[0042] By using the second component in combination with the first component, a solution-type composition can be provided that is soluble in so-called general-purpose solvents such as methyl ethyl ketone. The first component alone can only be dissolved in fluorine-based solvents, but is difficult to dissolve in general-purpose solvents, making it impossible to form a coating film with excellent finger-smoothing properties. On the other hand, fluorine-based solvents are a concern due to their environmental impact, and there are issues such as restrictions on the emission of volatile substances generated during coating processing. Therefore, in order to solve these problems, the present invention provides a composition that can form a coating film with excellent finger-smoothing properties only by combining the first component with the second component and dissolving it in a general-purpose solvent.

[0043] The fluorine group-containing (meth)acrylate monomer is not particularly limited as long as it is within the above-mentioned range of number average molecular weight, but a perfluoropolyether group-containing (meth)acrylate monomer can be suitably used. More specifically, a compound can be used which has a perfluoropolyether group as the main chain and in which a (meth)acryloyl group or a (meth)acryloyloxy group is bonded to both or one of the terminal groups via or without an alkylene group having 10 or less carbon atoms and in which some or all of the hydrogen atoms may be substituted with fluorine atoms.

[0044] Known or commercially available compounds can be used as such compounds. Commercially available products include, for example, products named "FLUOROLINK AD-1700," "FLUOROLINK MD-700," and "FLUOROLINK 5101X" (all manufactured by Solvay Specialty Polymers, Inc.). "FLUOROLINK AD-1700" is represented by the following general formula (3) (m and n are integers other than 0, and X is a (meth)acryloyl group-containing organic functional group). [ka]

[0045] The solid content of the second component in the composition of the present invention is not particularly limited, but is usually about 15 to 45 mass %, and preferably 22 to 40 mass %, which further improves the solubility of the first component in general-purpose solvents and, in turn, more reliably provides a coating film with excellent finger sliding properties, etc.

[0046] The ratio of the first component to the second component can be set appropriately depending on the type of the first component, etc., but it is particularly desirable to set the weight ratio of the first component:second component to be about 1:1.4 to 1:2, and even more desirable to set the weight ratio of the first component:second component to be 1:1.5 to 1:1.8. Setting the ratio within this range makes it easier for the first component to dissolve uniformly in a general-purpose organic solvent such as MEK, and it is possible to more reliably obtain a coating film that has better finger sliding properties and is highly transparent.

[0047] Third component The third component is a polyfunctional (meth)acrylate monomer (excluding the first and second components). The third component particularly fixes the first and second components to the substrate or lower layer more reliably, contributing to the development of coating film performance and durability. The polyfunctional (meth)acrylate monomer may be one with two or more functionalities, but trifunctional to hexafunctional ones are particularly preferred.

[0048] The polyfunctional (meth)acrylate monomer is a (meth)acrylate monomer having two or more functional groups each having a carbon-carbon unsaturated bond.

[0049] Examples of bifunctional (meth)acrylate monomers include alkylene glycol di(meth)acrylates such as ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and 1,9-nonanediol di(meth)acrylate; polyalkylene glycol di(meth)acrylates such as polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, and polybutylene glycol di(meth)acrylate; neopentyl glycol di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, polycarbonate diol di(meth)acrylate, polyester diol di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, propoxylated bisphenol A di(meth)acrylate, and polyurethane di(meth)acrylate.

[0050] Examples of trifunctional (meth)acrylate monomers include trimethylolpropane tri(meth)acrylate, ethoxylated isocyanuric acid tri(meth)acrylate, ε-caprolactone-modified tris((meth)acryloxyethyl)isocyanurate, and pentaerythritol tri(meth)acrylate.

[0051] Examples of the tetrafunctional (meth)acrylate monomer include ditrimethylolpropane tetra(meth)acrylate and pentaerythritol tetra(meth)acrylate.

[0052] An example of the pentafunctional (meth)acrylate monomer is dipentaerythritol penta(meth)acrylate.

[0053] An example of the hexafunctional (meth)acrylate monomer is dipentaerythritol hexa(meth)acrylate.

[0054] The solid content of the third component in the composition of the present invention is not particularly limited, but in order to ensure that the functions of the third component as described above are exhibited more reliably, it is usually about 20 to 70 mass %, and preferably 30 to 60 mass %.

[0055] Fourth component The fourth component is a photoinitiator (photopolymerization initiator), which ensures that the composition of the present invention can reliably initiate curing upon irradiation with ultraviolet light or the like.

[0056] Photoinitiators such as dimethyl-2,2'-azobis(2-methylpropionate), 4,4-bis(diethylamino)benzophenone, 2,4,6-trimethylbenzophene, methyl orthobenzoylbenzoate, 4-phenylbenzophenone, t-butylanthraquinone, 2-ethylanthraquinone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzophenone, benzil dimethyl ketal, 1-hydroxycyclohexyl-phenyl ketone, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, Examples of such photopolymerization initiators include 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, diethylthioxanthone, isopropylthioxanthone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, methylbenzoyl formate, 2-benzyl-2-dimethylamino-4-morpholinobutyrophenone, 2-(dimethylamino)-2-(4-methylbenzyl)-1-(4-morpholinophenyl)-butan-1-one, etc. Commercially available photopolymerization initiators can also be used.

[0057] The solid content of the fourth component in the composition of the present invention can be appropriately set depending on, for example, the type of polymerization initiator used, but from the viewpoint of the role of the fourth component described above, it is usually about 3 to 15 mass %, and preferably 5 to 10 mass %.

[0058] 5th component The fifth component contains an organic solvent. The type of organic solvent can be appropriately determined depending on the type of the first component, etc. In particular, in the present invention, it is preferable to use an organic solvent that contains at least one of ketone-based solvents, ester-based solvents, alcohol-based solvents, and amide-based solvents, which are commonly used among organic solvents that can uniformly dissolve the first component and the second component. It is preferable that the organic solvent does not contain a fluorine-based solvent.

[0059] Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone.

[0060] Examples of the ester solvent include ethyl acetate, butyl acetate, methoxybutyl acetate, and methoxypropyl acetate.

[0061] Examples of alcohol-based solvents include methanol, ethanol, 1-propanol, isopropyl alcohol, ethylene glycol monomethyl ether, and propylene glycol monomethyl ether (1-methoxy-2-propanol).

[0062] Examples of amide solvents include dimethylformamide (DMF), dimethylacetamide (DMAc), N-methylpyrrolidone (NMP), and diethylformamide.

[0063] The amount of organic solvent used is not critical and can be appropriately adjusted depending on, for example, the types of components used, the desired viscosity, etc., so that the solid content of the composition of the present invention is within the range of about 0.1 to 90% by weight (preferably about 0.1 to 50% by weight). For example, when the composition of the present invention is used in the form of a paste, the solid content can be set to be somewhat higher.

[0064] Other ingredients In addition to the first to fifth components, other components may be appropriately blended into the composition of the present invention as needed, provided that the effects of the present invention are not impaired. Examples of such components include crosslinkers, reactive diluents (such as monofunctional monomers), inorganic fine particles (fine particles of oxides such as silica, alumina, titania, and zirconia), antifouling agents (slip agents), surface conditioners, UV absorbers, light stabilizers, dispersants (surfactants), wetting agents, thickeners, antioxidants, polymerization inhibitors, silane coupling agents, and colorants.

[0065] B. Properties of the composition of the present invention The composition of the present invention is usually in a liquid form, and its viscosity (20°C) can be appropriately set depending on the desired thickness of the cured layer (hard coat), for example, but is not limited to, about 1 to 500 mPa·s.

[0066] In particular, the composition of the present invention is preferably in the form of a solution in which at least the first and second components are dissolved in the fifth component, an organic solvent. By forming the composition in solution form, a coating film that exhibits even better finger sliding properties can be formed.

[0067] C. Preparation of the Composition of the Invention The composition of the present invention can be prepared by uniformly mixing the above-mentioned components. The order of mixing is not particularly limited, and any order can be used.

[0068] The mixing can be carried out using a known or commercially available device such as a mixer, kneader, etc. The mixing atmosphere is usually room temperature and normal pressure, but is not limited thereto.

[0069] D. Uses of the Compositions of the Invention A desired cured layer can be formed by curing a coating film of the composition of the present invention. That is, a cured layer (cured film) having excellent finger slipperiness, water repellency, etc. can be more reliably obtained from the composition of the present invention.

[0070] The cured layer may be transparent, translucent, or opaque. In particular, when used as a protective film for a screen, etc., it is desirable that the cured layer be transparent or translucent. In this case, the transparency is not limited, but it is usually desirable that the haze value is about 0.1 to 5%.

[0071] The thickness of the cured layer can be appropriately set depending on the desired hardness, moldability, etc., but is usually about 0.1 μm or less, preferably 0.01 to 0.1 μm, and particularly preferably 0.01 to 0.05 μm. In particular, when an optically functional layer such as a refractive index control layer is provided as an underlying layer of the cured layer, setting the thickness as described above allows the optically functional layer to effectively exhibit its optical properties without interfering with them. In other words, the cured layer of the present invention can be suitably used as a cured layer for protecting the surface of the optically functional layer.

[0072] The method for forming the cured layer is not particularly limited, and can be suitably carried out, for example, by a method including the steps of: a) forming a coating film of the composition of the present invention on a substrate film; and b) curing the coating film.

[0073] The substrate film serving as the base (lower layer) of the cured layer is not particularly limited, and examples thereof include acrylic resins (such as polymethyl methacrylate), olefin resins (such as polyethylene and polypropylene), polyester resins (such as polyethylene terephthalate and polybutylene terephthalate), polyamide resins (such as nylon), polycarbonate resins, polyurethane resins, vinyl resins (such as vinyl chloride resins and vinyl acetate resins), fluorine-containing resins, silicone resins, etc. In particular, transparent films such as polyethylene terephthalate can be preferably used because of their excellent transparency.

[0074] The thickness of the substrate film can be appropriately changed depending on the application, etc., and can be, for example, about 0.05 to 1 mm, but is not limited to this.

[0075] The coating film of the composition of the present invention can be formed by any known coating method, such as doctor blade method, bar coating method, dipping method, air spray method, roller brush method, roller coater method, etc.

[0076] The amount of coating film formed may be, for example, an amount that will result in a desired thickness of the cured layer, and can usually be appropriately set so that the thickness of the resulting cured film is within a range of about 0.1 μm or less (preferably within a range of 0.01 to 0.05 μm).

[0077] The resulting coating film may be subjected to a drying step, if necessary, prior to curing. The drying method may be natural drying or a method in which the coating film is heated at a temperature of, for example, about 60 to 120°C.

[0078] Next, the coating film is cured. The method for curing the coating film is not particularly limited, but a curing method using radiation (active energy rays) can be preferably used. Any radiation may be used as long as it has an energy level sufficient to cleave the photopolymerization initiator. Examples of radiation include electromagnetic radiation and particle radiation, and it is particularly preferable to use ultraviolet light, infrared light, visible light, far-infrared light, etc.

[0079] In the present invention, ultraviolet light is particularly suitable because it allows for relatively easy curing. When irradiating with ultraviolet light, the light source is not limited, and examples include a high-pressure mercury lamp, an iron-doped metal halide lamp, a gallium lamp, a low-pressure mercury lamp, an ultra-high-pressure mercury lamp, an ultraviolet laser, and an LED. Therefore, curing can be performed using a known or commercially available device equipped with these.

[0080] When irradiating with ultraviolet light, the wavelength is, for example, in the range of about 100 to 400 nm, and the illuminance is 80 to 1000 mW / cm 2 Accumulated light intensity: 100-5000mJ / cm 2The ultraviolet irradiation can be performed using, but is not limited to, a known or commercially available UV irradiation device.

[0081] The temperature conditions for ultraviolet irradiation are not particularly limited, but are usually within the range of 100° C. or less. Therefore, for example, irradiation can be suitably carried out at around room temperature (about 10 to 40° C.).

[0082] 2. Film The present invention also encompasses a film (film of the present invention) comprising a cured layer of the composition of the present invention on the outermost surface. Accordingly, examples of the film of the present invention include not only a film composed of a single layer of the cured layer of the composition of the present invention, but also laminated films formed by laminating the cured layer with a substrate film or other layer. However, even in the case of a laminated film, at least the cured layer is disposed on the outermost surface.

[0083] The substrate film is not limited, and for example, the above-mentioned resin films can be suitably used. Furthermore, a release film can also be used as the substrate film in order to obtain a film consisting of a single layer of the cured layer of the composition of the present invention (on the premise that the cured layer will be peeled off during use).

[0084] Other layers that can be laminated with the cured layer of the composition of the present invention include, for example, a printed layer, an optically functional layer (refractive index control layer, antireflection layer, field of view control layer, etc.), an adhesive layer, an antistatic layer, etc., within the scope that does not impair the effects of the present invention. These can be formed according to known methods.

[0085] In particular, the present invention is preferably a film comprising an optically functional layer and the cured layer of the present invention laminated on the surface of the optically functional layer as the outermost layer. That is, a film in which the cured layer is formed to protect the surface of an optically functional layer such as an antireflection layer is desirable. The cured layer of the present invention can exhibit desired finger sliding properties and the like with a relatively thin thickness, thereby effectively bringing out the optical function of the optically functional layer.

[0086] As a more specific example of an embodiment, a film comprising: a) a substrate film; b) a refractive index control layer (lower layer) formed on the substrate film; and c) a cured layer (upper layer) of the composition of the present invention laminated in direct contact with the refractive index control layer can be suitably employed.

[0087] In this case, the substrate film and the cured layer can be formed according to the methods described above.

[0088] The refractive index control layer is not particularly limited as long as it can provide an antireflection function, and a known refractive index control layer (antireflection layer) or the like can be used. For example, a cured layer of a curable composition containing a polyfunctional (meth)acrylate monomer, oxide-containing fine particles, a polymerization initiator, and an organic solvent can be preferably used. Hereinafter, a cured layer of the curable composition will be shown as an example of an embodiment.

[0089] The polyfunctional (meth)acrylate monomer may be the same as the compounds exemplified above for the third component, and its content in the curable composition may be appropriately set within a range of about 1 to 10% by mass.

[0090] The oxide-containing microparticles may be known or commercially available microparticles added to optical materials, such as microparticles of inorganic oxides such as silica and zirconia, as well as microparticles composed of composite materials of these with resins. These microparticles may be solid or hollow. The shape of the microparticles is usually preferably spherical, but is not limited thereto. The average particle size of the microparticles may be, for example, about 0.005 to 0.1 μm. The content of the oxide-containing microparticles is not particularly limited, but may be appropriately set within a range of about 1 to 10 mass % in the curable composition.

[0091] The polymerization initiator may be the same as the compounds exemplified above for the fourth component, and its content in the curable composition may be appropriately set within a range of about 0.1 to 10% by mass.

[0092] The organic solvent may be the same as the solvents exemplified for the fifth component. In this case, the amount of the organic solvent used is not limited and may be appropriately determined depending on the types of components used, the desired viscosity, etc., so that the solid content falls within the range of, for example, about 5 to 90% by weight.

[0093] A refractive index control layer, which is a cured layer, is formed using a curable composition containing these compounds, and the method for forming the layer can be the same as the method for forming a cured layer using the composition of the present invention.

[0094] The thickness of the refractive index control layer (lower layer) is not particularly limited, but is usually about 0.05 to 1 μm, and preferably 0.1 to 0.5 μm.

[0095] 3.Optical products The present invention encompasses optical products in which the film of the present invention is laminated on a substrate. In particular, in the present invention, the screen surface of a display can be used as the substrate to protect the screen surface. Among these, it is desirable that the substrate is a display screen that serves as a touch sensor portion in a touch panel display.

[0096] Such touch panel displays (devices) may be any devices that require at least transparency and finger smoothness from the film. Examples include smartphones, tablet terminals, PC monitors, ticket vending machines, information displays, in-vehicle operation panels, digital cameras, multifunction devices (monitor units), portable game consoles, bank ATMs, digital audio players, etc. Products in which the film of the present invention is laminated on the surface of the display screen of these devices are also encompassed by the optical products of the present invention.

[0097] The method for laminating the film of the present invention on a substrate may be the same as the method for laminating a known or commercially available protective film, for example, a method in which the film is attached to the substrate with a removable adhesive interposed between the substrate and the film, but is not limited thereto.

[0098] As described above, the film of the present invention may be a single layer of cured layer or a laminate including a combination of an optically functional layer and a cured layer. In the former case, the film has a structure of substrate / cured layer. In the latter case, the film may have a structure of substrate / (optically functional layer / cured layer), substrate / (substrate film / optically functional layer / cured layer), etc. [Example]

[0099] The features of the present invention will be described in more detail below with reference to examples and comparative examples, but the scope of the present invention is not limited to these examples.

[0100] Example 1 A curable composition of the present invention (Coating Solution A) was prepared by uniformly mixing the components shown in the "upper layer" column of Table 1. On the other hand, a curable composition for forming a lower layer (Coating Solution B) was prepared by uniformly mixing the components shown in the "lower layer" column of Table 1. The unit of the composition (numerical values) of each component in Table 1 is "% by mass." Next, a commercially available polyethylene terephthalate (PET) film (Cosmoshine A4100, manufactured by Toyobo Co., Ltd.) was used as the base film, and a lower layer and an upper layer were formed thereon in this order. More specifically, Coating Solution B was coated onto the PET film using a No. 3 bar coater, and dried in an oven (ESP Corporation, dryer SPH-102) at 90°C for 1 minute. Next, Coating Solution A diluted 10-fold with MEK was coated onto the surface of the lower layer using a No. 4 bar coater, and dried in the oven at 90°C for 1 minute. Next, ultraviolet irradiation (illuminance 500 mW / cm) was performed using an ultraviolet irradiation device (UV curing lamp "H06-L41" manufactured by Eye Graphics Co., Ltd., conveyor-type ultraviolet irradiation device "ECS-601"). 2 , cumulative light intensity 500mJ / cm 2 ) was carried out to cure each layer. In this way, a laminate in which a lower layer and an upper layer were formed on a PET film was obtained.

[0101] Examples 2 to 7 A laminate was produced in the same manner as in Example 1, except that the coating liquids used to form the upper and lower layers were changed to the compositions shown in Table 1.

[0102] Comparative Examples 1 to 3 A laminate was produced in the same manner as in Example 1, except that the coating liquids used to form the upper and lower layers were changed to the compositions shown in Table 1.

[0103] [Table 1]

[0104] The following products or substances obtained by the manufacturing methods were used as the components shown in Table 1. In addition, the "molecular weight" below all means "number average molecular weight."

[0105] (1) Long-chain PFPE acrylate 1 Solvay Specialty Polymers' ZMF-402 (3.0 mmol, 12.00 g), Showa Denko's Karenz AOI (3.6 mmol, 0.508 g), Fujifilm Wako Pure Chemical Industries' triethylamine (0.3 mmol, 0.030 g), and 12.0 g of 3M's Novec HFE-7200 were weighed into a 50 ml recovery flask containing a stir bar. The reaction solution was stirred at 60 °C for 6 hours. After the reaction, Fujifilm Wako Pure Chemical Industries' methanol was added to the reaction solution, allowing it to separate into layers. The lower layer was the target product, and the solvent in the upper layer was removed. This washing process using methanol was repeated three times. The product was placed in a recovery flask and dried under reduced pressure to remove the solvent, resulting in the synthesis of the target perfluoropolyether-containing acrylate (11.2 g, 90% yield). In this way, a long-chain PFPE acrylate 1 (molecular weight 4200) having an acrylate at one end of a perfluoropolyether having a molecular weight of 4000 was obtained. (2) Long-chain PFPE acrylate 2 A 10 ml recovery flask containing a stir bar was charged with Fluorolink D-6000 (0.5 mmol, 3.00 g) manufactured by Solvay Specialty Polymers, Karenz BEI (1.2 mmol, 0.287 g) manufactured by Showa Denko, triethylamine (0.05 mmol, 0.05 g) manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., and 3.0 g of Novec HFE-7200 manufactured by 3M. The reaction solution was stirred at 60 °C for 6 hours. After the reaction, methanol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added to the reaction solution, allowing it to separate into layers. The lower layer was the target product, and the solvent in the upper layer was removed. This washing process using methanol was repeated three times. The product was placed in a recovery flask and dried under reduced pressure to remove the solvent, resulting in the synthesis of 2.89 g of the target perfluoropolyether-containing acrylate with a yield of 88%. In this way, a long-chain PFPE acrylate 2 (molecular weight 6500) having acrylate groups at both ends of a perfluoropolyether having a molecular weight of 6000 was obtained. (3) AD-1700 Fluorolink AD-1700: Manufactured by Solvay Specialty Polymers, Inc. A perfluoropolyether material with acrylate at both ends and a molecular weight of approximately 1500 (70% non-volatile content, molecular weight 1700) (4) M-306 Aronix M-306: manufactured by Toagosei Co., Ltd., a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (pentaerythritol triacrylate content: 65-70%) (5) A-9550W NK Ester A-9550W: a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (ratio of dipentaerythritol pentaacrylate: dipentaerythritol hexaacrylate = 50:50 (weight ratio)), manufactured by Shin-Nakamura Chemical Co., Ltd. (6) MEK-AC-2140Z MEK-AC-2140Z: Nissan Chemical Industries, Ltd., acrylate-modified silica fine particles (40% non-volatile content) (7) Thruria 4320 Sururia 4320: JGC Catalysts and Chemicals Co., Ltd., acrylate-modified hollow silica fine particles (non-volatile content 20%) (8) Omnirad 184 Omnirad 184: IBM RESINS BV: 1-Hydroxycyclohexyl-phenyl ketone (9) MEK Methyl ethyl ketone (MEK): Kanto Chemical Co., Ltd. (10) AcOEt Ethyl acetate (AcOEt): manufactured by Kanto Chemical Co., Ltd. (11)DMF N,N-Dimethylformamide (DMF): DuPont (12) PGM 1-Methoxy-2-propanol (PGM): Nippon Nyukazai Co., Ltd.

[0106] Test Example 1 The laminates obtained in each of the examples and comparative examples were examined for the following properties, and the results are also shown in Table 1.

[0107] (1) Hayes Measurement was performed using a haze meter NDH5000 manufactured by Nippon Denshoku Industries Co., Ltd.

[0108] (2) Film Thickness Measurements were made using an F20 film thickness measurement system manufactured by Filmetrics Inc. Film thickness was measured at three randomly selected locations, and the average value was calculated.

[0109] (3) Contact angle The contact angle with water was measured using "Drop Master 700" manufactured by Kyowa Interface Science Co., Ltd. The measurement temperature was 20°C.

[0110] (4) Coefficient of kinetic friction Measurements were taken using Shinto Scientific's "Tribogear Type 14FW" under the following conditions: terminal: medicine wrapping paper, load: 500g, measurement speed: 300mm / min, scanning distance: 30mm.

[0111] (5) Finger smoothness A sensory test was conducted in which a finger was traced about 10 cm over the coating surface five times. More specifically, the surface of the upper layer (cured layer of the present invention) was lightly traced back and forth with a finger five times, as if touching an actual tablet or smartphone, and the tactile sensation was evaluated. The evaluation criteria were as follows: "Good" if the finger glides without catching; "Average" if the finger catches once in five times (no problem in actual use); and "Poor" if the finger always catches without catching.

[0112] (6) Oil-based ink repellency / wipeability Letters were written on the surface of the upper layer using a Zebra Corporation's Macky Knock Black oil-based pen, and then wiped off after drying. The wiping method involved sliding a Pro Wipe five times. The evaluation criteria were as follows: if the ink was repelled in dots and could be wiped off, it was given a "○"; if the ink was not repelled but could be wiped off, it was given a "△"; and if the ink was not repelled and could not be wiped off, it was given an "×".

[0113] As is clear from the results in Table 1, all of the Examples exhibited excellent results in terms of finger sliding properties, etc. For example, it was found that the dynamic friction coefficient was as low as 0.12 or less (particularly 0.1 or less).

[0114] In particular, a comparison of Examples 1 and 3 with Comparative Example 2 revealed that the coating film containing the first component formed on a coating film containing colloidal silica or hollow silica, which are refractive index control materials, exhibited excellent performance, but the coating film in which the second component was added directly to the refractive index control layer exhibited poor slip properties and ink repellency.

[0115] Comparing Examples 1 and 2 with Comparative Example 1, when the proportion of the first component in the solid content was 10% by mass or more, the dynamic friction coefficient was below 0.12, and high ink repellency and water contact angle were exhibited. On the other hand, when the proportion was below 10% by mass, the slipperiness or liquid repellency was poor.

[0116] In Comparative Example 3, the first and second components were mixed in a 1:1 ratio (active ingredient equivalent), resulting in the coating liquid becoming cloudy, the haze of the coating film exceeding 10%, and a significant decrease in transparency.

[0117] As can be seen from the results of Examples 1 and 4, when the PFPE molecular weight of the first component was 4,000 or 6,000, good coating film performance was obtained.

[0118] The results of Examples 1, 5, 6, and 7 show that by incorporating the second component, it becomes possible to prepare a desired coating liquid using various general-purpose solvents such as ketone-based solvents.

[0119] From the results of Examples 1 and 8, it is clear that the advantageous effects of the present invention can be achieved by using a polyfunctional (meth)acrylate of the third component having three to six functional groups.

Claims

1. The following ingredients: (1) a perfluoropolyether group-containing acrylate monomer having a number average molecular weight of 3,000 or more and 7,500 or less; (2) A fluorine group-containing acrylate monomer having a number average molecular weight of 500 or more but less than 3,000, which has a perfluoropolyether group as its main chain and has (meth)acryloyl or (meth)acryloyloxy groups bonded to both or one of its terminal groups with or without an alkylene group having 10 or less carbon atoms and in which some or all of the hydrogen atoms may be substituted with fluorine atoms; (3) Polyfunctional acrylate monomers (excluding the acrylate monomers (1) and (2) above), (4) a photoinitiator; and (5) Organic solvents Including, The solid content of the perfluoropolyether group-containing acrylate monomer is 10 to 30% by weight, The fluorine group-containing acrylate monomer is contained in an amount of 150 parts by weight or more per 100 parts by weight of the perfluoropolyether group-containing acrylate monomer. A curable composition characterized by:

2. The curable composition according to claim 1, wherein the perfluoropolyether group-containing acrylate monomer is a compound represented by the general formula A-PFPE-B (wherein PFPE represents a perfluoropolyether group, and one or both of A and B are (meth)acryloyl group-containing organic functional groups, and if A or B is not a (meth)acryloyl group-containing organic functional group, it is an alkyl group having 10 or less carbon atoms in which some or all of the hydrogen atoms may be substituted with fluorine atoms).

3. The (meth)acryloyl group-containing organic functional group is (1) An organic functional group represented by -R 2 -R 1 (R 1 is a (meth)acryloyl group or a (meth)acryloyloxy group, and R2 is an alkylene group having 10 or less carbon atoms in which some or all of the hydrogen atoms may be substituted with fluorine atoms), (2) An organic functional group represented by -R 2 -OCONH-R 1 (R 1 is a (meth)acryloyl group or a (meth)acryloyloxy group, and R 2 is an alkylene group having 10 or less carbon atoms in which some or all of the hydrogen atoms may be substituted with fluorine atoms), or (3) An organic functional group represented by -R 2 -OCONH-R 3 -(R 1 )n (R 1 is a (meth)acryloyl group or a (meth)acryloyloxy group, R 2 is an alkylene group having 10 or less carbon atoms in which some or all of the hydrogen atoms may be substituted with fluorine atoms, R 3 is a hydrocarbon group having 1 to 10 carbon atoms which may have a branched chain, and n is an integer of 1 or 2). The curable composition according to claim 2, wherein

4. The curable composition according to any one of claims 1 to 3, wherein the organic solvent comprises at least one of a ketone-based solvent, an ester-based solvent, an alcohol-based solvent, and an amide-based solvent.

5. A film having a cured layer of the curable composition according to any one of claims 1 to 4 disposed as an outermost layer.

6. The film of claim 5, wherein the thickness of the cured layer is 0.01 to 0.1 μm.

7. An optical product comprising the film according to claim 5 or 6 laminated on a substrate.

8. The optical product according to claim 7 , wherein the substrate is a display screen that serves as a touch sensor portion in a touch panel display.

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