Curable composition for hard coat

Abstract

[Problem] To provide a homogeneous curable composition that is free of suspended matter and sediment, and is capable of forming a hard coat layer provided with high-standard characteristics, both in durability and in smoothness, as well as high liquid repellency when actual use thereof is assumed. [Solution] Provided is a curable composition that includes: (a) 100 parts by mass of an active energy ray-curable polyfunctional monomer having two or more (meth)acryloyl groups per molecule; (b) 0.05 -2 parts by mass of perfluoropolyether having, via a poly(oxyalkylene) group, an active energy ray-polymerizable group only in one end of a molecular chain which includes a poly(oxyperfluoroalkylene) group, and having a weight average molecular weight of 1500-3500; and (c) 1-20 parts by mass of a polymerization initiator which generates radicals due to active energy rays.

Description

Curable composition for hard coating

[0001] The present invention relates to a curable composition useful as a material for forming a hard coat layer to be applied to the surface of various display elements, and relates to a homogeneous curable composition free from suspended matter and sediment, capable of forming a hard coat layer that is excellent in slipperiness, scratch resistance, abrasion resistance, and water repellency.

[0002] In recent years, touch panels have been introduced into a variety of devices, including mobile phones, tablet computers, and other portable information terminal devices, notebook computers, home appliances, and automotive interior and exterior components. Touch panel surfaces of display elements such as liquid crystal displays and organic electroluminescence (EL) displays are often operated by touching them with a finger or pen. When operating with a finger, the surface of the touch panel must be water- and oil-repellent to facilitate the removal of fingerprints, and must also be abrasion-resistant to maintain its water- and oil-repellent properties even when repeatedly rubbed with a finger. In addition, when operating the surface of a touch panel with a finger or pen, the surface must be slippery to provide a comfortable feel to the finger or pen. Furthermore, the surface of a touch panel must be scratch-resistant to prevent scratches. To impart these properties to the surface of a touch panel, a surface coating layer, such as a hard coating layer, is provided.

[0003] Fluorine-containing compounds exhibit high slip properties and water and oil repellency, and are therefore used as materials for forming hard coat layers. For example, a method is used in which a small amount of a fluorine-based surface modifier is added to a coating liquid for forming a hard coat layer to form a composition. It is known that fluorine-based surface modifiers segregate on the surface of the hard coat layer due to the low surface energy of fluorine atoms.

[0004] Generally, in order to impart scratch resistance and abrasion resistance to a hard coat layer, a method is adopted in which a high-density crosslinked structure is formed to increase the surface hardness of the hard coat layer and provide resistance to external forces.Currently, as a material for forming such a hard coat layer, a multifunctional acrylate-based material that undergoes three-dimensional crosslinking by radicals generated by irradiation with active energy rays is most commonly used.For the fluorine-based surface modifier added to the coating solution for forming the hard coat layer, a material having an active energy ray-polymerizable group is generally used to impart scratch resistance and abrasion resistance to the hard coat layer (Patent Document 1).

[0005] On the other hand, as described in Patent Document 2, when a fluorine-based surface modifier having a crosslinkable group is used to obtain durable properties such as scratch resistance and abrasion resistance in a hard coat layer, the molecular chain containing fluorine atoms is fixed, and the slipperiness of the hard coat layer is reduced. In other words, there is a trade-off between durable properties such as scratch resistance and abrasion resistance and slipperiness, and it is difficult to achieve high levels of both properties at the same time.

[0006] To improve the trade-off relationship, there is a method of introducing a crosslinkable group only at one end of a molecular chain containing a fluorine atom to enhance the mobility of the molecular chain containing a fluorine atom. However, compared to the method of introducing a crosslinkable group at both ends of a molecular chain containing a fluorine atom, the slipperiness of the hard coat layer is superior, but the durability generally tends to be inferior. In addition, the molecular chain containing a fluorine atom is easily aggregated, and when preparing a coating solution for forming the hard coat layer, the coating solution tends to become cloudy. If the fluorine-based surface modifier aggregates in the coating solution for forming the hard coat layer, when the hard coat layer is formed using the coating solution, the molecular chain containing a fluorine atom will not segregate sufficiently on the surface of the hard coat layer, and the original properties of slipperiness, water repellency, and scratch resistance will not be exhibited.

[0007] One possible approach to improving the solubility of a fluorine-based surface modifier is to reduce the fluorine atom content of the fluorine-based surface modifier, for example by shortening the molecular chain containing fluorine atoms. However, this would result in a decrease in the slipperiness and water repellency of the hard coat layer, making it difficult to achieve high levels of slipperiness and water repellency.

[0008] As a method for improving the solubility of a fluorine-based surface modifier, Patent Document 3 reports the use of a fluorine-containing polyether, which forms aggregates when a hard coating composition is obtained and causes the composition to become cloudy, in combination with a fluorine-containing block copolymer that has excellent compatibility with the composition.

[0009] International Publication No. 2016 / 163479 Patent No. 6497449 JP 2005-179613 A

[0010] Since Patent Document 3 discloses that the fluorine-containing block copolymer described therein has inferior water repellency and lubricity compared to fluorine-containing polyethers, it is easy to imagine that the fluorine concentration of the fluorine-containing block copolymer is lower than that of the fluorine-containing polyethers, and it is difficult to achieve compatibility with the composition while also achieving slipperiness and water repellency. The present invention aims to provide a homogeneous curable composition free of suspended matter and sediment, which can form a hard coat layer that achieves a high level of durability and slipperiness, which are in a trade-off relationship. In addition, in anticipation of practical use, it is necessary for the hard coat layer to also have high liquid repellency.

[0011] A first aspect of the present invention is a curable composition comprising: (a) 100 parts by mass of an active energy ray-curable polyfunctional monomer having two or more (meth)acryloyl groups in one molecule; (b) 0.05 to 2 parts by mass of a perfluoropolyether having an active energy ray-polymerizable group, via a poly(oxyalkylene) group, at only one end of a molecular chain containing a poly(oxyperfluoroalkylene) group, and having a weight-average molecular weight of 1500 to 3500; and (c) 1 to 20 parts by mass of a polymerization initiator that generates radicals when exposed to active energy rays.

[0012] Another aspect of the present invention is a curable composition comprising: (a) 100 parts by mass of an active energy ray-curable polyfunctional monomer having two or more (meth)acryloyl groups in one molecule; (b) 0.05 to 2 parts by mass of a perfluoropolyether that is a reaction product between a starting material perfluoropolyether having a number average molecular weight of 1500 to 3000 and having a hydroxy group bonded to a poly(oxyalkylene) group at only one end of a molecular chain containing a poly(oxyperfluoroalkylene) group, and a compound having a functional group reactive with the hydroxy group and an active energy ray-polymerizable group; and (c) 1 to 20 parts by mass of a polymerization initiator that generates radicals when exposed to active energy rays.

[0013] The (b) perfluoropolyether has the active energy ray-polymerizable group at only one end of the molecular chain containing the poly(oxyperfluoroalkylene) group, via the poly(oxyalkylene) group, and has a weight-average molecular weight of 1,500 to 3,500.

[0014] The (b) perfluoropolyether has the active energy ray-polymerizable group via a urethane bond bonded to the poly(oxyalkylene) group.

[0015] The poly(oxyalkylene) group is a poly(oxyethylene) group.

[0016] The poly(oxyperfluoroalkylene) group has the repeating unit -(CF ２ O)- and / or repeating units -(CF ２ CF ２ When the repeating unit has both repeating units, the repeating units are bonded in a block bond, a random bond, or a block and random bond.

[0017] The molecular chain containing the poly(oxyperfluoroalkylene) group has a structure represented by the following formula [1]: (In the above formula [1], m represents a repeating unit -(CF ２ CF ２ O)-, and n is the number of repeating units -(CF ２0)-, satisfying 5≦(m+n)≦30, m and n each independently represent an integer of 0 or more, and q is the number of oxyethylene groups and represents an integer of 2 to 20.

[0018] In the formula [1], m and n each independently represent an integer of 1 or more.

[0019] The (b) perfluoropolyether is a compound represented by the following formula [2]: (In the above formula [2], m, n, and q are defined as in the above formula [1], and A represents the terminal group having the active energy ray-polymerizable group.)

[0020] The terminal group A is a group represented by the following formula [A1] or [A2]. (In the above formula [A1] and formula [A2], R １ and R ２ each independently represents a hydrogen atom or a methyl group, and * represents a bond to the urethane bond of the compound represented by formula [2].

[0021] The curable composition of the present invention further comprises (d) a solvent.

[0022] Another aspect of the present invention is a cured film obtained from the curable composition of the present invention.

[0023] Another embodiment of the present invention is a hard-coated film comprising a hard-coat layer on at least one surface of a film substrate, the hard-coat layer comprising the cured film.

[0024] A layer below the hard coat layer is present between the surface of the film substrate and the hard coat layer, and the film substrate is a resin film.

[0025] The hard coat layer has a thickness of 1 μm to 20 μm.

[0026] Another aspect of the present invention is a method for producing a hard coat film, comprising the steps of applying the curable composition of the present invention onto a film substrate to form a coating film, and irradiating the coating film with active energy rays to cure it, thereby forming a hard coat layer.

[0027] Another aspect of the present invention is a method for producing a hard coat film, comprising the steps of applying the curable composition of the present invention onto a film substrate to form a coating film, removing the solvent from the coating film by heating, and irradiating the coating film with active energy rays to cure it, thereby forming a hard coat layer.

[0028] The method for producing a hard coat film further includes a step of forming a lower layer of the hard coat layer on the surface of the film substrate, wherein the film substrate is a resin film and the coating film is formed on the lower layer of the hard coat layer.

[0029] Another aspect of the present invention is a perfluoropolyether compound having an active energy ray-polymerizable group at only one end of a molecular chain containing a poly(oxyperfluoroalkylene) group, via a poly(oxyalkylene) group, and having a weight-average molecular weight of 1,500 to 3,500.

[0030] Another aspect of the present invention is a perfluoropolyether compound which is a reaction product of a starting perfluoropolyether having a number average molecular weight of 1,500 to 3,000 and having a hydroxy group bonded to a poly(oxyalkylene) group at only one end of a molecular chain containing a poly(oxyperfluoroalkylene) group, and a compound having a functional group reactive with the hydroxy group and an active energy ray-polymerizable group.

[0031] The perfluoropolyether compound has the active energy ray-polymerizable group at only one end of the molecular chain containing the poly(oxyperfluoroalkylene) group, via the poly(oxyalkylene) group, and has a weight average molecular weight of 1,500 to 3,500.

[0032] The molecular chain containing the poly(oxyperfluoroalkylene) group has a structure represented by the following formula [1]. (In the above formula [1], m represents a repeating unit -(CF ２ CF ２ O)-, and n is the number of repeating units -(CF ２0)-, satisfying 5≦(m+n)≦30, m and n each independently represent an integer of 0 or more, and when both repeating units are present, these repeating units are bonded by block bonds, random bonds, or block bonds and random bonds, and q is the number of oxyethylene groups and represents an integer of 2 to 20.

[0033] In the formula [1], m and n each independently represent an integer of 1 or more.

[0034] The perfluoropolyether compound is a compound represented by the following formula [2]. (In the above formula [2], m, n, and q are defined as in the above formula [1], and A represents a terminal group having the above active energy ray-polymerizable group and represented by the following formula [A1] or [A2].) (In the above formula [A1] and formula [A2], R １ and R ２ each independently represents a hydrogen atom or a methyl group, and * represents a bond to the urethane bond of the compound represented by formula [2].

[0035] According to the present invention, it is possible to provide a curable composition having excellent homogeneity, which is useful for forming a cured film and a hard coat layer that exhibits excellent scratch resistance, abrasion resistance, and excellent slippage even in a thin film having a thickness of 1 μm to 20 μm. Furthermore, according to the present invention, it is possible to provide a hard coat film having a cured film obtained from the curable composition or a hard coat layer comprising the cured film, and it is possible to provide a hard coat film that exhibits excellent slippage and durability properties such as scratch resistance and abrasion resistance, which are in a trade-off relationship. Furthermore, according to the present invention, it is possible to provide a curable composition useful for forming a cured film and a hard coat layer that exhibits high water repellency in addition to exhibiting both of the above properties, and a hard coat film having a hard coat layer that exhibits these properties.

[0036] <Curable Composition> Each component of the curable composition of the present invention will be described below.

[0037] [(a) Active Energy Ray-Curable Polyfunctional Monomer Having Two or More (Meth)acryloyl Groups in One Molecule] The active energy ray-curable polyfunctional monomer of the component (a) having two or more (meth)acryloyl groups in one molecule (hereinafter also simply referred to as "(a) polyfunctional monomer") refers to a monomer that undergoes a polymerization reaction and hardens when irradiated with active energy rays such as ultraviolet rays.

[0038] Preferred examples of the (a) polyfunctional monomer in the curable composition of the present invention include monomers selected from the group consisting of polyfunctional (meth)acrylate compounds, and also include monomers selected from the group consisting of polyfunctional urethane (meth)acrylate compounds and monomers selected from the group consisting of lactone-modified polyfunctional (meth)acrylate compounds, as described below. In the present invention, the (a) polyfunctional monomer can be one selected from the group consisting of the above polyfunctional (meth)acrylate compounds, or a combination of two or more selected from the group consisting of the above polyfunctional (meth)acrylate compounds. In the present invention, the (meth)acrylate compound includes both an acrylate compound and a methacrylate compound, and for example, (meth)acrylic acid includes acrylic acid and methacrylic acid.

[0039] The (a) polyfunctional monomer may also be an oxyalkylene-modified polyfunctional monomer, and examples of the oxyalkylene-modified monomer include oxymethylene-modified, oxyethylene-modified, and oxypropylene-modified. Examples of the oxyalkylene-modified polyfunctional monomer include oxyalkylene-modified compounds of the above-mentioned polyfunctional (meth)acrylate compounds or polyfunctional urethane (meth)acrylate compounds. The oxyalkylene-modified polyfunctional monomers can also be used alone or in combination of two or more.

[0040] In addition, preferred examples of the (a) polyfunctional monomer in the present invention include polyfunctional monomers having at least two (meth)acryloyl groups in one molecule, preferably at least three in one molecule, and more preferably at least four in one molecule.

[0041] Examples of the polyfunctional (meth)acrylate compound (provided that it does not have a urethane bond) include trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, glycerin tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate, ethoxylated dipentaerythritol hexa(meth)acrylate, ethoxylated glycerin tri(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, and 1,3-propanediol di(meth)acrylate. acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 2-methyl-1,8-octanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, bis(2-hydroxyethyl)isocyanurate di(meth)acrylate, tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate, tricyclo[5.2.1.0 ２，６] decanedimethanol di(meth)acrylate, dioxane glycol di(meth)acrylate, 2-hydroxy-1-acryloyloxy-3-methacryloyloxypropane, 2-hydroxy-1,3-di(meth)acryloyloxypropane, 9,9-bis[4-(2-(meth)acryloyloxyethoxy)phenyl]fluorene, bis[4-(meth)acryloylthiophenyl]sulfide, bis[2-(meth)acryloylthioethyl]sulfide, 1,3-adamantanediol di(meth)acrylate, 1,3-adamantanedimethanol di(meth)acrylate, polyethylene glycol di(meth)acrylate, and polypropylene glycol di(meth)acrylate can be mentioned. Among these, preferred polyfunctional (meth)acrylate compounds include pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, and dipentaerythritol hexa(meth)acrylate.

[0042] Examples of the oxyalkylene-modified polyfunctional (meth)acrylate compound include (meth)acrylate compounds of polyols modified with oxyalkylene. Examples of the polyols include glycerin, diglycerin, triglycerin, tetraglycerin, pentaglycerin, hexaglycerin, decaglycerin, polyglycerin, trimethylolpropane, ditrimethylolpropane, pentaerythritol, and dipentaerythritol.

[0043] The polyfunctional urethane (meth)acrylate compound is a compound having a plurality of acryloyl groups or methacryloyl groups in one molecule and having one or more urethane bonds [—NHC(═O)O—], and may further have a urea bond [—NHC(═O)NH—]. Examples of the polyfunctional urethane (meth)acrylate compound include a compound obtained by reacting a polyfunctional isocyanate with a (meth)acrylate having a hydroxy group, and a compound obtained by reacting a polyfunctional isocyanate with a (meth)acrylate having a hydroxy group, and a polyol, but the polyfunctional urethane (meth)acrylate compound that can be used in the present invention is not limited to these examples.

[0044] Examples of the polyfunctional isocyanate include tolylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, and hexamethylene diisocyanate. Examples of the (meth)acrylate having a hydroxy group include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, and tripentaerythritol hepta(meth)acrylate. Examples of the polyol include diols such as ethylene glycol, propylene glycol, neopentyl glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, and dipropylene glycol; polyester polyols that are reaction products of these diols with aliphatic dicarboxylic acids or dicarboxylic anhydrides such as succinic acid, maleic acid, and adipic acid; polyether polyols; and polycarbonate diols.

[0045] The (a) polyfunctional monomer may be a lactone-modified polyfunctional (meth)acrylate compound, and the modifying lactone is preferably ε-caprolactone. Examples of the lactone-modified polyfunctional (meth)acrylate compound include ε-caprolactone-modified pentaerythritol tri(meth)acrylate, ε-caprolactone-modified pentaerythritol tetra(meth)acrylate, ε-caprolactone-modified dipentaerythritol penta(meth)acrylate, and ε-caprolactone-modified dipentaerythritol hexa(meth)acrylate.

[0046] [(b) Perfluoropolyether having an active energy ray polymerizable group via a poly(oxyalkylene) group at only one end of a molecular chain containing a poly(oxyperfluoroalkylene) group, and having a weight-average molecular weight of 1500 to 3500] A perfluoropolyether having an active energy ray polymerizable group via a poly(oxyalkylene) group at only one end of a molecular chain containing a poly(oxyperfluoroalkylene) group of the component (b), and having a weight-average molecular weight of 1500 to 3500, will be referred to simply as "(b) perfluoropolyether" below. (b) Perfluoropolyether can be obtained, for example, by reacting a raw material perfluoropolyether having a number-average molecular weight of 1500 to 3000 and having a hydroxy group bonded to a poly(oxyalkylene) group at only one end of a molecular chain containing the poly(oxyperfluoroalkylene) group, with a compound having a functional group reactive with the hydroxy group and the active energy ray polymerizable group. Examples of the functional group reactive with the hydroxy group include a hydroxy group, a carboxy group, and an isocyanate group. The (b) perfluoropolyether preferred in the curable composition of the present invention has the active energy ray-polymerizable group at only one end of the molecular chain containing the poly(oxyperfluoroalkylene) group via a urethane bond bonded to the poly(oxyalkylene) group.

[0047] Since the (b) perfluoropolyether has a poly(oxyalkylene) group, it has excellent compatibility with the (a) polyfunctional monomer, and the (b) perfluoropolyether alone can function as a surface modifier in the hard coat layer formed from the curable composition of the present invention. As the poly(oxyalkylene) group, a poly(oxyethylene) group is preferred.

[0048] (b) perfluoropolyether is not limited to those that have one active energy ray polymerizable group at only one end of molecular chain that comprises poly(oxyperfluoroalkylene) group, via poly(oxyalkylene) group, but can also have two or more active energy ray polymerizable groups.As this active energy ray polymerizable group, for example, (meth)acryloyl group and vinyl group can be enumerated, and as the terminal group that has this active energy ray polymerizable group, for example, can be enumerated as the group represented by above formula [A1] or formula [A2].Among these terminal groups, the group represented by formula [A2] that has two active energy ray polymerizable groups is preferred.

[0049] From the viewpoint of obtaining a cured film having good scratch resistance, the poly(oxyperfluoroalkylene) group is —[CF ２ O]-(oxyperfluoromethylene group) and -[CF ２ CF ２ In this case, the bond between these oxyperfluoroalkylene groups may be either a block bond or a random bond.

[0050] The (b) perfluoropolyether preferably has a fluorine atom content of 35% by mass or more and 60% by mass or less, more preferably 40% by mass or more and 55% by mass or less. When the fluorine atom content is 35% by mass or more, a hard coat layer with excellent water repellency and slipperiness can be obtained, and when it is 60% by mass or less, it is sufficiently compatible with the (a) polyfunctional monomer, and a hard coat layer with little cloudiness can be obtained.

[0051] The weight-average molecular weight of (b) perfluoropolyether is 1500 to 3500, preferably 1600 to 3500, more preferably 1700 to 3000. When the weight-average molecular weight of (b) perfluoropolyether is within the above range, (b) perfluoropolyether is more likely to remain on the surface of the hard coat layer obtained from the curable composition of the present invention, and the shear stress on the layer surface is sufficiently small, so that a hard coat layer with excellent slipperiness can be obtained. In addition, when the weight-average molecular weight of (b) perfluoropolyether is within the above range, the hardness of the layer surface can be appropriately adjusted, and a hard coat layer with excellent durability such as scratch resistance can be obtained. In other words, when the weight-average molecular weight of (b) perfluoropolyether is within the above range, it is possible to achieve both slipperiness and durability.

[0052] In the curable composition of the present invention, the content of (b) perfluoropolyether is 0.05 to 2 parts by mass relative to 100 parts by mass of the (a) polyfunctional monomer. When the content of (b) perfluoropolyether is 0.05 parts by mass or more, the (b) perfluoropolyether is present in sufficient quantity on the surface of the hard coat layer obtained from the curable composition of the present invention, so that a hard coat layer with excellent slip properties can be obtained. Furthermore, when the content of (b) perfluoropolyether is 2 parts by mass or less, it is sufficiently compatible with the (a) polyfunctional monomer, so that a hard coat layer with little cloudiness can be obtained.

[0053] (b) The perfluoropolyethers may be used singly or in combination of two or more.

[0054] [(c) Polymerization Initiator] The (c) polymerization initiator preferred in the curable composition of the present invention is, for example, a polymerization initiator that generates radicals when exposed to active energy rays such as electron beams, ultraviolet rays, or X-rays, particularly ultraviolet rays.

[0055] Examples of the (c) polymerization initiator include benzoins, alkylphenones, thioxanthones, azo compounds, azides, diazo compounds, o-quinonediazides, acylphosphine oxides, oxime esters, organic peroxides, benzophenones, biscoumarins, bisimidazoles, titanocenes, thiols, halogenated hydrocarbons, trichloromethyltriazines, and onium salts such as iodonium salts and sulfonium salts. These polymerization initiators may be used alone or in combination of two or more. In the present invention, from the viewpoints of transparency, surface curability, and thin-film curability, it is preferable to use alkylphenones as the (c) polymerization initiator. The use of alkylphenones makes it possible to obtain a cured film with improved scratch resistance.

[0056] Examples of the alkylphenones include α-hydroxyalkylphenones such as 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2-hydroxy-1-(4-(2-hydroxyethoxy)phenyl)-2-methylpropan-1-one, and 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)-2-methylpropan-1-one; α-aminoalkylphenones such as 2-methyl-1-(4-(methylthio)phenyl)-2-morpholinopropan-1-one and 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butan-1-one; 2,2-dimethoxy-1,2-diphenylethan-1-one; and methyl phenylglyoxylate.

[0057] In the curable composition of the present invention, the content of the polymerization initiator (c) is 1 to 20 parts by mass, preferably 2 to 10 parts by mass, per 100 parts by mass of the polyfunctional monomer (a).

[0058] [(d) Solvent] The curable composition of the present invention may contain a (d) solvent as an optional component, i.e., may be in the form of a varnish. The (d) solvent may be appropriately selected in consideration of the solubility / dispersibility of the components (a) to (c), the workability during application of the curable composition for forming a cured film (hard coat layer) described below, the drying properties before and after curing, etc.

[0059] Examples of the solvent (d) include aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, and tetralin; aliphatic or alicyclic hydrocarbons such as n-hexane, n-heptane, mineral spirits, and cyclohexane; halides such as methyl chloride, methyl bromide, methyl iodide, dichloromethane, chloroform, carbon tetrachloride, trichloroethylene, perchloroethylene, and o-dichlorobenzene; esters or ester ethers such as ethyl acetate, propyl acetate, butyl acetate, methoxybutyl acetate, methyl cellosolve acetate, ethyl cellosolve acetate, and propylene glycol monomethyl ether acetate (PGMEA); diethyl ether, tetrahydrofuran (THF), 1,4-dioxane, methyl cellosolve, ethyl cellosolve, butyl cellosolve, propylene glycol monomethyl ether, and propylene glycol monoethyl ether. ethers such as propylene glycol ether (PGME), propylene glycol mono-n-propyl ether, propylene glycol monoisopropyl ether, and propylene glycol mono-n-butyl ether; ketones such as acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), di-n-butyl ketone, and cyclohexanone; alcohols such as methanol, ethanol, n-propanol, isopropyl alcohol, n-butanol, isobutyl alcohol, tert-butyl alcohol, 2-ethylhexyl alcohol, benzyl alcohol, and ethylene glycol; amides such as N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), and N-methyl-2-pyrrolidone (NMP); and sulfoxides such as dimethyl sulfoxide (DMSO), as well as mixtures of two or more of these solvents.

[0060] The content of the solvent (d) in the curable composition of the present invention is not particularly limited, but is, for example, a concentration such that the solid content concentration of the curable composition of the present invention is 1% by mass to 70% by mass, preferably 5% by mass to 50% by mass. Here, the solid content concentration (also referred to as non-volatile content concentration) represents the content of the solid content (all components excluding the solvent component) relative to the total mass (total mass) of the components (a) to (d) and other additives in the curable composition of the present invention.

[0061] [Other Additives] Furthermore, the curable composition of the present invention may contain, as needed, one or more of the additives that are generally added, such as a polymerization inhibitor, a photosensitizer, a leveling agent, a surfactant, an adhesion imparting agent, a plasticizer, an ultraviolet absorber, a storage stabilizer, an antistatic agent, an inorganic filler, a pigment, and a dye, which may be blended alone or in combination, as long as the effects of the present invention are not impaired.

[0062] <Cured film> The curable composition of the present invention can be applied (coated) onto a substrate to form a coating film, and the coating film can be polymerized (cured) by irradiating it with active energy rays to form a cured film, and the cured film is also within the scope of the present invention. In addition, the cured film can be used as a hard coat layer in a hard coat film described below.

[0063] Examples of the substrate include various resins (polyesters such as polycarbonate, polymethacrylate, polystyrene, polyethylene terephthalate (PET), and polyethylene naphthalate (PEN), polyurethane, thermoplastic polyurethane (TPU), polyolefin, polyamide, polyimide, epoxy resin, melamine resin, triacetyl cellulose (TAC), acrylonitrile-butadiene-styrene copolymer (ABS), acrylonitrile-styrene copolymer (AS), norbornene-based resin), metal, wood, paper, glass, and slate. These substrates may be in the form of a plate, film, or three-dimensional molded article. Furthermore, on the surface of the substrate, for example, a primer layer, an ultraviolet absorbing layer, an infrared absorbing layer, a near-infrared absorbing layer, an electromagnetic wave absorbing layer, a color correction layer, a refractive index adjusting layer, a weather-resistant layer, an antireflection layer, an antistatic layer, a discoloration preventing layer, a gas barrier layer, a water vapor barrier layer, a light-scattering layer, an electrode layer, or the like may be formed as an underlayer of the hard coat layer, or a plurality of underlayers of the hard coat layer may be laminated. The layer formed on the surface of the substrate is not particularly limited as long as it does not impair the effects of the present invention.

[0064] The method for applying the composition to the substrate can be appropriately selected from cast coating, spin coating, blade coating, dip coating, roll coating, spray coating, bar coating, die coating, inkjet printing, and printing methods (such as relief printing, intaglio printing, lithographic printing, and screen printing). Among these, roll-to-roll methods are preferred. From the viewpoint of thin-film coating properties, relief printing, particularly gravure coating, is preferred. The curable composition of the present invention is preferably filtered beforehand using a filter having a pore size of approximately 0.2 μm before application. If necessary, a solvent may be added to the curable composition during application. Examples of the solvent include the various solvents listed in the above section [(e) Solvent].

[0065] After the curable composition of the present invention is applied to a substrate to form a coating film, the coating film is pre-dried as needed using a heating means such as a hot plate or oven to remove the solvent (solvent removal step). The heat drying conditions are preferably, for example, 40°C to 120°C and 30 seconds to 10 minutes. After drying, the coating film is cured by irradiating it with active energy rays such as ultraviolet light. Examples of active energy rays include ultraviolet light, electron beams, and X-rays, with ultraviolet light being particularly preferred. Examples of light sources that can be used for ultraviolet irradiation include sunlight, chemical lamps, low-pressure mercury lamps, high-pressure mercury lamps, metal halide lamps, xenon lamps, and UV-LEDs. The polymerization may then be completed by post-baking, specifically by heating using a heating means such as a hot plate or oven.

[0066] The thickness of the cured film formed after drying and curing is usually 0.1 to 20 μm, preferably 0.5 to 10 μm.

[0067] <Hard Coat Film> Using the curable composition of the present invention, a hard coat film having a hard coat layer on at least one side (surface) of a film substrate can be produced. The hard coat film is also within the scope of the present invention, and the hard coat film is suitably used for protecting the surfaces of various display elements such as touch panels and liquid crystal displays.

[0068] The hard coat layer in the hard coat film of the present invention can be formed by a method including the steps of applying the curable composition of the present invention to a film substrate to form a coating film, removing the solvent by heating as necessary, and irradiating the coating film with active energy rays such as ultraviolet rays to cure the coating film. A method for producing a hard coat film having a hard coat layer on at least one surface of a film substrate, including these steps, is also within the scope of the present invention.

[0069] As the film substrate, various transparent resin films usable for optical applications among the substrates listed in the above <Cured film> can be used. Preferred resin films include films of polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene naphthalate (PEN), polyurethane, thermoplastic polyurethane (TPU), polycarbonate, polymethacrylate, polystyrene, polyolefin, polyamide, polyimide, triacetyl cellulose (TAC), and the like.

[0070] The film substrate may be formed by laminating a plurality of layers. For example, a layer different from the resin film, such as a primer layer, an ultraviolet absorbing layer, an infrared absorbing layer, a near-infrared absorbing layer, an electromagnetic wave absorbing layer, a color correction layer, a refractive index adjusting layer, a weather-resistant layer, an antireflection layer, an antistatic layer, a discoloration preventing layer, a gas barrier layer, a water vapor barrier layer, a light scattering layer, or an electrode layer, may be laminated on the surface of the resin film as an underlayer of the hard coat layer, or a plurality of underlayers of the hard coat layer may be laminated. The layer laminated on the surface of the resin film is not particularly limited as long as it does not impair the effects of the present invention.

[0071] The method for applying the curable composition of the present invention to the film substrate (coating film forming step) and the method for irradiating the coating film with active energy rays (curing step) can be the methods listed above in <Cured film>. When the curable composition of the present invention contains a solvent (in the form of a varnish), the coating film may be dried to remove the solvent after the coating film forming step, if necessary. In this case, the method for drying the coating film (solvent removal step) listed above in <Cured film> can be used.

[0072] The thickness (film thickness) of the hard coat layer thus obtained is, for example, 1 μm to 20 μm, and preferably 1 μm to 10 μm.

[0073] <Perfluoropolyether Compound> The present invention also covers perfluoropolyether compounds that are reaction products between a raw material perfluoropolyether having a number average molecular weight of 1,500 to 3,000 and having a hydroxy group bonded to a poly(oxyalkylene) group at only one end of a molecular chain containing a poly(oxyperfluoroalkylene) group, and a compound having a functional group that reacts with the hydroxy group and an active energy ray-polymerizable group.

[0074] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples. In the examples, the apparatus and conditions used for sample preparation and physical property analysis are as follows:

[0075] (1) Coating by bar coater Apparatus: PM-9050MC manufactured by SMT Corporation Bar: A-Bar manufactured by OSG System Products Co., Ltd. OSP-30 Maximum wet film thickness 30 μm (film thickness after drying 6 μm) or OSP-15 Maximum wet film thickness 15 μm (film thickness after drying 3 μm) Coating speed: 4 m / min (2) Film thickness measurement Apparatus: F20 Film thickness measurement system manufactured by Filmetrics Inc. (3) Oven Apparatus: Two-layer clean oven (top and bottom type) PO-250-45-D manufactured by Sanki Keiso Co., Ltd. (4) UV curing Apparatus: CV-110QC-G manufactured by Heraeus Co., Ltd. Lamp: Electrodeless lamp H-bulb manufactured by Heraeus Co., Ltd. (5) Scratch resistance test and abrasion resistance test Apparatus: Reciprocating abrasion tester manufactured by Shinto Scientific Co., Ltd. TRIBOGEAR TYPE: 30S Scanning speed: 3200 mm / min Scanning distance: 50 mm (6) Contact angle measurement Apparatus: DropMaster DM-501 manufactured by Kyowa Interface Science Co., Ltd. Measurement temperature: 23°C (7) Dynamic friction coefficient measurement Apparatus: Load-varying friction and wear test system manufactured by Shinto Scientific Co., Ltd. TRIBOGEAR (registered trademark) TYPE: HHS2000 Probe: 0.6 mmR sapphire pin Load: 200 g Scanning speed: 2 mm / sec Scanning distance: 10 mm (8) Total light transmittance, haze measurement Apparatus: Haze meter NDH5000 manufactured by Nippon Denshoku Industries Co., Ltd. (9) Weight-average molecular weight measurement Gel permeation chromatography (GPC) Apparatus: HLC-8420GPC manufactured by Tosoh Corporation Column: manufactured by Tosoh Corporation TSKgel G2000HXL, TSKgel G3000HXL Measurement temperature: 40°C Eluent: tetrahydrofuran Detection: RI (10) Combustion ion chromatography Automatic sample combustion system: AQF-2100 H manufactured by Nitto Seiko Analytech Co., Ltd. (formerly Mitsubishi Chemical Analytech Co., Ltd.) Ion chromatograph: Dionex Integration manufactured by Thermo Fisher Scientific Co., Ltd. Sample: 2 mg Absorption solution: 2.7 mM sodium carbonate + 0.3 mM sodium bicarbonate aqueous solution Eluent: 2.7 mM sodium carbonate + 0.3 mM sodium bicarbonate aqueous solution Column: AG-12A / AS-12A manufactured by Thermo Fisher Scientific Co., Ltd. Flow rate: 1.5 mL / min Detector: Electrical conductivity (suppressor used)Standard sample: Fluoride ion standard solution (F-1000) manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. (formerly Wako Pure Chemical Industries, Ltd.). When the solvent in the sample did not contain a solvent containing fluorine atoms, the fluorine concentration was measured in the state where the solvent was included, and the fluorine concentration of the solute was calculated by converting it from the solid concentration.

[0076] The abbreviations have the following meanings: Multifunctional acrylate PA1: dipentaerythritol pentaacrylate / hexaacrylate mixture [Aronix (registered trademark) M-403, manufactured by Toagosei Co., Ltd.] Multifunctional acrylate PA2: oxyethylene-modified multifunctional acrylate [New Frontier (registered trademark) MF-001, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.] Multifunctional acrylate PA3: multifunctional urethane acrylate [Art Resin (registered trademark) UN-3320HS, manufactured by Negami Chemical Industrial Co., Ltd.] Multifunctional acrylate PA4: pentaerythritol triacrylate / pentaerythritol tetraacrylate [PET30, manufactured by Nippon Kayaku Co., Ltd.] PFPE1: perfluoropolyether having one hydroxy group at only one end via a poly(oxyethylene) group, and having the following structure [Fomblin (registered trademark) 4102X, manufactured by Solvay Specialty Polymers] １９ F-NMR and １ Number average molecular weight calculated from H-NMR analysis results: 1900 (In the above formula, m represents the repeating unit -(CF ２ CF ２ O)-, and n is the number of repeating units -(CF ２ PFPE2: Perfluoropolyether having one hydroxy group at only one end without a poly(oxyalkylene) group and having the following structure [7324X manufactured by Solvay Specialty Polymers] １９ F-NMR and １ Number average molecular weight calculated from the results of H-NMR analysis: 1750 to 1950] (In the above formula, m represents the repeating unit -(CF ２ CF ２ O)-, and n is the number of repeating units -(CF２ PFPE3: a perfluoropolyether having one hydroxy group at only one end without a poly(oxyalkylene) group and having the following structure [FO2, molecular weight 978.15, manufactured by Apollo Scientific] PFPE4: Perfluoropolyether (1H,1H-perfluoro-3,6,9-trioxatridecan-1-ol) having one hydroxy group at only one end without a poly(oxyalkylene) group, and having the following structure [C10GOL, molecular weight 548.1, manufactured by Exfluor Research] N1: 1,1-bis(acryloyloxymethyl)ethyl isocyanate [Karenz (registered trademark) BEI, manufactured by Showa Denko K.K.] N2: 2-acryloyloxyethyl isocyanate [Karenz (registered trademark) AOI, manufactured by Showa Denko K.K.] N3: 2-methacryloyloxyethyl isocyanate [Karenz (registered trademark) MOI, manufactured by Showa Denko K.K.] DOTDD: dioctyltin dineodecanoate [Neostan (registered trademark) U-830, manufactured by Nitto Kasei Co., Ltd.] SMA7: perfluoropolyether having a total of four active energy ray-polymerizable groups at both ends of the molecular chain containing a poly(oxyperfluoroalkylene) group [Solvay Specialty Polymers Fluorolink (registered trademark) AD-1700, 70% by mass nonvolatile solution, weight average molecular weight measured by GPC in terms of polystyrene: Mw is 3973, dispersity: Mw / Mn is 2.1 (Mn is number average molecular weight), fluorine atom content in the perfluoropolyether compound calculated by combustion ion chromatography: 29% by mass] MEK: methyl ethyl ketone PGME: propylene glycol monomethyl ether PGMEA: propylene glycol monomethyl ether acetate O2959: 2-hydroxy-1-(4-(2-hydroxyethoxy)phenyl)-2-methylpropan-1-one [OMNIRAD (registered trademark) 2959 manufactured by IGM Resins]

[0077] [Production Example 1] Production of perfluoropolyether compound SMA1 3.08 g (1.6 mmol) of PFPE1, 0.39 g (1.6 mmol) of N1, 0.035 g of DOTDD (0.01 times the total mass of PFPE1 and N1), and 3.5 g of PGMEA were charged into a screw tube. This mixture was stirred at room temperature (approximately 23 ° C.) for 72 hours using a stirrer tip to obtain a 50 mass% PGMEA solution of the target perfluoropolyether compound SMA1. The weight average molecular weight (Mw) of the obtained SMA1 measured in polystyrene equivalent by GPC was 1908, and the dispersity (Mw / Mn) was 1.0. The fluorine atom content in SMA1 calculated by combustion ion chromatography was 47 mass%.

[0078] [Production Example 2] Production of perfluoropolyether compound SMA2 3.23 g (1.7 mmol) of PFPE1, 0.24 g (1.7 mmol) of N2, 0.035 g of DOTDD (0.01 times the total mass of PFPE1 and N2), and 3.5 g of PGMEA were charged into a screw tube. This mixture was stirred at room temperature (approximately 23 ° C) for 72 hours using a stirrer tip to obtain a 50 mass% PGMEA solution of the target perfluoropolyether compound SMA2. The weight average molecular weight (Mw) of the obtained SMA2 measured in terms of polystyrene by GPC was 1894, and the dispersity (Mw / Mn) was 1.1.

[0079] [Production Example 3] Production of perfluoropolyether compound SMA3 3.20 g (1.7 mmol) of PFPE1, 0.26 g (1.7 mmol) of N3, 0.035 g of DOTDD (0.01 times the total mass of PFPE1 and N3), and 3.5 g of PGMEA were charged into a screw tube. This mixture was stirred at room temperature (approximately 23 ° C) for 72 hours using a stirrer tip to obtain a 50 mass% PGMEA solution of the target perfluoropolyether compound SMA3. The weight average molecular weight (Mw) of the obtained SMA3 measured in polystyrene equivalent by GPC was 1868, and the dispersity (Mw / Mn) was 1.1.

[0080] [Production Example 4] Production of perfluoropolyether compound SMA4 2.20 g (1.2 mmol) of PFPE2, 0.28 g (1.2 mmol) of N1, 0.025 g of DOTDD (0.01 times the total mass of PFPE2 and N1), and 0.6 g of MEK were charged into a screw tube. This mixture was stirred at room temperature (approximately 23 ° C.) for 72 hours using a stirrer tip to obtain an 80 mass% MEK solution of the target perfluoropolyether compound SMA4. The weight average molecular weight (Mw) of the obtained SMA4 measured in terms of polystyrene by GPC was 1710, and the dispersity (Mw / Mn) was 1.0. The fluorine atom content in SMA4 calculated by combustion ion chromatography was 63 mass%.

[0081] [Production Example 5] Production of perfluoropolyether compound SMA5 2.78 g (2.9 mmol) of PFPE3, 0.68 g (2.9 mmol) of N1, 0.035 g of DOTDD (0.01 times the total mass of PFPE3 and N1), and 3.5 g of PGMEA were charged into a screw tube. This mixture was stirred at room temperature (approximately 23 ° C.) for 72 hours using a stirrer tip to obtain a 50 mass% PGMEA solution of the target perfluoropolyether compound SMA5. The weight average molecular weight (Mw) of the obtained SMA5 measured in polystyrene equivalent by GPC was 1299, and the dispersity (Mw / Mn) was 1.0. The fluorine atom content in SMA5 calculated by combustion ion chromatography was 51 mass%, which was similar to the fluorine atom content (51 mass%) theoretically calculated from the structure of SMA5.

[0082] [Production Example 6] Production of perfluoropolyether compound SMA6 2.41 g (4.4 mmol) of PFPE4, 1.05 g (4.4 mmol) of N1, 0.035 g of DOTDD (0.01 times the total mass of PFPE4 and N1), and 3.5 g of PGMEA were charged into a screw tube. This mixture was stirred at room temperature (approximately 23 ° C.) for 72 hours using a stirrer tip to obtain a 50 mass% PGMEA solution of the target perfluoropolyether compound SMA6. The weight average molecular weight (Mw) of the obtained SMA6 measured in terms of polystyrene by GPC was 1029, and the dispersity (Mw / Mn) was 1.0. The fluorine atom content in SMA5 calculated by combustion ion chromatography was 46 mass%, which was similar to the fluorine atom content of 47 mass% theoretically calculated from the structure of SMA5.

[0083] [Examples 1 to 8, Comparative Examples 1 to 4] The components shown in Table 1 were mixed to prepare curable compositions having the solid content concentrations shown in Table 1. Here, the solid content refers to components other than the solvent. In Table 2, [parts] represents [parts by mass] and [%] represents [% by mass]. In Table 1, the polyfunctional acrylate and surface modifier each represent the solid content.

[0084]

[0085] These curable compositions were applied with a bar coater onto an A4-sized PET film [Lumirror (registered trademark) U403 (also known as U40) manufactured by Toray Industries, Inc., thickness 100 μm] on both sides of which a primer layer had been formed by easy-adhesion treatment, to obtain a coating film. This coating film was dried in an oven at 60°C for 8 minutes to remove the solvent. The obtained film was then exposed to light at an exposure dose of 300 mJ / cm under a nitrogen atmosphere. ２ By irradiating and exposing the film with UV light, a hard coat film having a hard coat layer (cured film) with a film thickness of 3 μm or 6 μm was produced.

[0086] The homogeneity of each curable composition, as well as the scratch resistance, water repellency, abrasion resistance, slipperiness, and haze of the obtained hard coat film were evaluated. The evaluation procedures are shown below. The results are also shown in Table 2. [Composition homogeneity] The appearance of each prepared curable composition was visually confirmed and evaluated according to the following criteria. A: Transparent solution (no floating matter, sediment, or phase separation) C: Presence of floating matter, sediment, or phase separation [Scratch resistance] The hard coat layer surface of the obtained hard coat film was rubbed 2,500 times with steel wool [BONSTAR (registered trademark) #0000 (ultrafine)] attached to a reciprocating abrasion tester under a load of 1 kg with a stroke of 50 mm. Thereafter, the degree of scratches in the area excluding the 5 mm wide ranges at both ends of the 50 mm stroke was visually confirmed, and in addition, it was confirmed using a microscope (Keyence Corporation) that the scratches were on the surface of the hard coat layer, and the evaluation was performed according to the following criteria A, B, and C. When considering actual use as a hard coat layer, at least B is required, and A is preferable. A: No scratches (0 scratches) B: Scratches occurred (1 to 4 scratches with a length of 1 mm to 9 mm) C: Scratches occurred (5 or more scratches with a length of 1 mm to 9 mm, or 1 or more scratches with a length of 1 cm or more) [Water repellency] 1 μL of water was applied to the surface of the hard coat layer, and the contact angle θ was measured 5 times after 10 seconds, and the average value was used to evaluate according to the following criteria. When considering actual use as a hard coat layer, at least B is required, and A is preferable. A: θ≧105° B: 90°≦θ<105° C: θ<90° [Abrasion Resistance] The hard coat layer surface was rubbed 2,500 times with a cylindrical eraser [Minoan RUBBER STICK, φ6.0 mm] attached to a reciprocating abrasion tester under a load of 1 kg. 1 μL of water was applied to the rubbed area, and the contact angle θ was measured at 5 points after 5 seconds, and the average value was used as the contact angle value, and evaluated according to the following criteria. Note that, assuming actual use as a hard coat layer, A is desirable. A: θ≧90° B: 80°≦θ<90° C: 80°<θ [Slipperiness] The dynamic friction coefficient μ' was measured at 5 points on the hard coat layer surface, and the average value was used to evaluate according to the following criteria.The smaller the dynamic friction coefficient value, the smaller the friction with the probe used, and serves as a guide for slipperiness. The smaller the dynamic friction coefficient value, the better the slipperiness when touched, so the smaller the dynamic friction coefficient value, the more preferable. A: μ'≦0.035 B: 0.035<μ'≦0.050 C: μ'>0.050 [Haze] As a reference value, the haze was measured at three locations on the surface of the hard coat layer, and the average value was calculated. The haze of the PET film used as the substrate [Lumirror (registered trademark) U403 (also known as U40), 100 μm thick, manufactured by Toray Industries, Inc.] was 1.6.

[0087]

[0088] As shown in Table 1, the curable compositions of Examples 1 to 8 contain polyfunctional acrylates PA1 to PA4, and perfluoropolyether PFPE1 having a number average molecular weight of 1900 and one hydroxy group bonded to a poly(oxyethylene) group at only one end of a molecular chain containing a poly(oxyperfluoroalkylene) group, and one of isocyanate compounds N1 to N3 having an active energy ray-polymerizable group, to obtain SMA1 having a weight average molecular weight of 1908, SMA2 having a weight average molecular weight of 1894, or SMA3 having a weight average molecular weight of 1868. As shown in Table 2, the curable compositions of Examples 1 to 8 exhibited excellent homogeneity, and the hard coat films having hard coat layers obtained from the curable compositions exhibited excellent slip properties, scratch resistance, water repellency, and abrasion resistance.

[0089] On the other hand, as shown in Table 1, the curable composition of Comparative Example 1 contains SMA4 having a weight average molecular weight of 1,710 obtained by reacting a perfluoropolyether compound PFPE2 having a number average molecular weight of 1,750 to 1,950 and having one hydroxy group, not via a poly(oxyalkylene) group, at only one end of the molecular chain containing a poly(oxyperfluoroalkylene) group, with an isocyanate compound N1 having an active energy ray-polymerizable group. The curable composition of Comparative Example 2 contains SMA5 having a weight average molecular weight of 1,299 obtained by reacting a perfluoropolyether compound PFPE3 having a molecular weight of 978.15 and having one hydroxy group, not via a poly(oxyalkylene) group, at only one end of the molecular chain containing a poly(oxyperfluoroalkylene) group, with an isocyanate compound N1 having an active energy ray-polymerizable group. As shown in Table 2, the curable compositions of Comparative Examples 1 and 2 had poor homogeneity. In addition, the hard coat films having hard coat layers obtained from these curable compositions had poor slip properties and abrasion resistance compared to the hard coat films having hard coat layers obtained from the curable compositions of Examples 1 to 8, because the cohesive force of SMA4 and SMA5 was high and SMA4 and SMA5 were unable to segregate sufficiently on the surface of the hard coat layer.

[0090] Furthermore, as shown in Table 1, the curable composition of Comparative Example 3 contains polyfunctional acrylate PA1 and SMA6 having a weight average molecular weight of 1029, which was obtained by reacting a perfluoropolyether compound PFPE4 having a molecular weight of 548.1 and having one hydroxy group at only one end of the molecular chain containing a poly(oxyperfluoroalkylene) group, without an intervening poly(oxyalkylene) group, with an isocyanate compound N1 having the active energy ray-polymerizable group. As shown in Table 2, although the curable composition of Comparative Example 3 had good homogeneity, the hard coat film having a hard coat layer obtained from the curable composition had inferior slip properties, scratch resistance, and abrasion resistance compared to the hard coat films having hard coat layers obtained from the curable compositions of Examples 1 to 8, due to the short molecular chain containing the poly(oxyperfluoroalkylene) group of SMA6.

[0091] As shown in Table 1, the curable composition of Comparative Example 4 contains polyfunctional acrylate PA1 and a perfluoropolyether compound SMA7 having an active energy ray-polymerizable group at both ends of a molecular chain containing a poly(oxyperfluoroalkylene) group and a weight-average molecular weight of 3973. As shown in Table 2, the curable composition of Comparative Example 4 has good homogeneity, but the hard coat film having a hard coat layer obtained from the curable composition has poor molecular mobility of the poly(oxyperfluoroalkylene) chain because SMA7 has an active energy ray-polymerizable group at both ends of a molecular chain containing a poly(oxyperfluoroalkylene) group. As a result, the hard coat film had poor slip properties and abrasion resistance compared to the hard coat films having hard coat layers obtained from the curable compositions of Examples 1 to 8.

Claims

1. (a) 100 parts by mass of an active energy ray-curable polyfunctional monomer having two or more (meth)acryloyl groups in one molecule, (b) 0.05 to 2 parts by mass of a perfluoropolyether having an active energy ray-polymerizable group, via a poly(oxyalkylene) group, at only one end of a molecular chain containing a poly(oxyperfluoroalkylene) group and having a weight average molecular weight of 1,500 to 3,500, and (c) 1 part by mass to 20 parts by mass of a polymerization initiator that generates radicals when exposed to active energy rays, The molecular chain containing the poly(oxyperfluoroalkylene) group has a structure represented by the following formula [1]: The curable composition, wherein the (b) perfluoropolyether is a compound represented by the following formula [2]: 【Chemistry 1】 (In the above formula [1], m is the number of repeating units -(CF 2 CF 2 O)-, and n is the number of repeating units -(CF 2 O)-, satisfying 5≦(m+n)≦30, m and n each independently represent an integer of 0 or more, and when both repeating units are present, these repeating units are bonded by block bonds, random bonds, or block bonds and random bonds, and q is the number of oxyethylene groups and represents an integer of 2 to 20.) 【Chemistry 2】 (In the above formula [2], m, n, and q are defined as those in the above formula [1], and A represents a terminal group having the above-mentioned active energy ray-polymerizable group and represented by the following formula [A1] or formula [A2].) 【Chemistry 3】 (In the above formula [A1] and formula [A2], R 1 and R 2 each independently represent a hydrogen atom or a methyl group, and * represents a bond to the urethane bond of the compound represented by formula [2].)

2. (a) 100 parts by mass of an active energy ray-curable polyfunctional monomer having two or more (meth)acryloyl groups in one molecule, (b) 0.05 to 2 parts by mass of a perfluoropolyether which is a reaction product between a raw material perfluoropolyether having a number average molecular weight of 1,500 to 3,000 and a hydroxy group bonded to a poly(oxyalkylene) group at only one end of a molecular chain containing a poly(oxyperfluoroalkylene) group, and a compound having a functional group reactive with the hydroxy group and an active energy ray-polymerizable group, and (c) 1 part by mass to 20 parts by mass of a polymerization initiator that generates radicals when exposed to active energy rays, The molecular chain containing the poly(oxyperfluoroalkylene) group has a structure represented by the following formula [1]: The curable composition, wherein the (b) perfluoropolyether is a compound represented by the following formula [2]: 【Chemistry 4】 (In the above formula [1], m is the number of repeating units -(CF 2 CF 2 O)-, and n is the number of repeating units -(CF 2 O)-, satisfying 5≦(m+n)≦30, m and n each independently represent an integer of 0 or more, and when both repeating units are present, these repeating units are bonded by block bonds, random bonds, or block bonds and random bonds, and q is the number of oxyethylene groups and represents an integer of 2 to 20.) 【Chemistry 5】 (In the above formula [2], m, n, and q are defined as those in the above formula [1], and A represents a terminal group having the above-mentioned active energy ray-polymerizable group and represented by the following formula [A1] or formula [A2].) 【Chemistry 6】 (In the above formula [A1] and formula [A2], R 1 and R 2 each independently represent a hydrogen atom or a methyl group, and * represents a bond to the urethane bond of the compound represented by formula [2].)

3. The curable composition according to claim 2 , wherein the perfluoropolyether (b) has a weight average molecular weight of 1,500 to 3,500.

4. The curable composition according to claim 1 , wherein in the formula [1], m and n each independently represent an integer of 1 or more.

5. The curable composition according to claim 1 , further comprising: (d) a solvent.

6. A cured film obtained from the curable composition according to any one of claims 1 to 5.

7. A hard coat film comprising a hard coat layer on at least one surface of a film substrate, the hard coat layer comprising the cured film according to claim 6.

8. 8. The hard coat film according to claim 7, further comprising a lower layer of the hard coat layer between the surface of the film substrate and the hard coat layer, the film substrate being a resin film.

9. 9. The hard coat film according to claim 7, wherein the hard coat layer has a thickness of 1 μm to 20 μm.

10. 6. A method for producing a hard coat film, comprising: applying the curable composition according to claim 1 onto a film substrate to form a coating film; and irradiating the coating film with active energy rays to cure the coating film, thereby forming a hard coat layer.

11. 6. A method for producing a hard coat film, comprising the steps of: applying the curable composition according to claim 5 onto a film substrate to form a coating film; removing the solvent from the coating film by heating; and irradiating the coating film with active energy rays to cure the coating film to form a hard coat layer.

12. The method for producing a hard coat film according to claim 10 or 11, further comprising a step of forming a lower layer of the hard coat layer on a surface of the film substrate, the film substrate being a resin film, and the coating film being formed on the lower layer of the hard coat layer.

13. a perfluoropolyether compound having the active energy ray-polymerizable group via a poly(oxyalkylene) group at only one end of a molecular chain containing a poly(oxyperfluoroalkylene) group, and having a weight average molecular weight of 1,500 to 3,500, The molecular chain containing the poly(oxyperfluoroalkylene) group has a structure represented by the following formula [1]: The perfluoropolyether compound is a compound represented by the following formula [2]: 【Chemistry 7】 (In the above formula [1], m is the number of repeating units -(CF 2 CF 2 O)-, and n is the number of repeating units -(CF 2 O)-, satisfying 5≦(m+n)≦30, m and n each independently represent an integer of 0 or more, and when both repeating units are present, these repeating units are bonded by block bonds, random bonds, or block bonds and random bonds, and q is the number of oxyethylene groups and represents an integer of 2 to 20.) 【Chemistry 8】 (In the above formula [2], m, n, and q are defined as those in the above formula [1], and A represents a terminal group having the above-mentioned active energy ray-polymerizable group and represented by the following formula [A1] or formula [A2].) 【Chemistry 9】 (In the above formula [A1] and formula [A2], R 1 and R 2 each independently represent a hydrogen atom or a methyl group, and * represents a bond to the urethane bond of the compound represented by formula [2].)

14. A perfluoropolyether compound which is a reaction product between a raw material perfluoropolyether having a number average molecular weight of 1500 to 3000 and a hydroxyl group bonded to a poly(oxyalkylene) group at only one end of a molecular chain containing a poly(oxyperfluoroalkylene) group, and a compound having a functional group reactive with the hydroxyl group and an active energy ray polymerizable group, wherein the molecular chain containing the poly(oxyperfluoroalkylene) group has a structure represented by the following formula [1]: The perfluoropolyether compound is a compound represented by the following formula [2]: 【Chemistry 10】 (In the above formula [1], m is the number of repeating units -(CF 2 CF 2 O)-, and n is the number of repeating units -(CF 2 O)-, satisfying 5≦(m+n)≦30, m and n each independently represent an integer of 0 or more, and when both repeating units are present, these repeating units are bonded by block bonds, random bonds, or block bonds and random bonds, and q is the number of oxyethylene groups and represents an integer of 2 to 20.) 【Chemistry 11】 (In the above formula [2], m, n, and q are defined as those in the above formula [1], and A represents a terminal group having the above-mentioned active energy ray-polymerizable group and represented by the following formula [A1] or formula [A2].) 【Chemistry 12】 (In the above formula [A1] and formula [A2], R 1 and R 2 each independently represent a hydrogen atom or a methyl group, and * represents a bond to the urethane bond of the compound represented by formula [2].)

15. The perfluoropolyether compound according to claim 14, having a weight average molecular weight of 1,500 to 3,500.

16. The perfluoropolyether compound according to any one of claims 13 to 15, wherein in the formula [1], m and n each independently represent an integer of 1 or more.

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