KR20230173736A - Curable composition for extensible, scratch-resistant coating - Google Patents

Abstract

[Problem] To provide a material for forming a hard coat layer that has stretchability and excellent scratch resistance and also exhibits a transparent appearance.
[Solution means] (a) 100 parts by mass of an active energy ray-curable lactone-modified multifunctional monomer, (b) at both ends of the molecular chain containing a poly(oxyperfluoroalkylene) group through urethane bonds, and applying active energy Perfluoropolyether having a pre-polymerizable group (however, perfluoropolyether having a poly(oxyalkylene) group between the poly(oxyperfluoroalkylene) group and the urethane bond is excluded.) 0.1 to 10 A hard coat film comprising a curable composition comprising 1 to 20 parts by mass of a polymerization initiator that generates radicals by active energy rays, and (c) a hard coat layer formed from the composition.

Description

Curable composition for stretchable scratch-resistant coating {CURABLE COMPOSITION FOR EXTENSIBLE, SCRATCH-RESISTANT COATING}

The present invention relates to a curable composition useful as a forming material for a hard coat layer applied to the surfaces of various display elements such as touch panel displays and liquid crystal displays. In detail, it relates to a curable composition that has extensibility and excellent scratch resistance and can form a hard coat layer that exhibits a transparent appearance.

Resin molded products are widely used in portable information terminal devices such as mobile phones and tablet-type computers, laptop-type personal computers, home appliances, and automobile interior and exterior parts. In order to improve the design of these resin molded products, the surface is usually decorated by printing or the like after molding the resin. Recently, as a method of decorating the three-dimensional surface of the resin molded product, a decorative film is used in which a hard coat layer is provided on one side of the film and a printing layer or an adhesive layer is provided on the other side, and these decorative films are used. , a method of attaching it to a resin molded product through an adhesive layer is being studied.

Among the required characteristics of the decorative film, first of all, moldability is required. In other words, stretchability that can follow a three-dimensional surface is required so that cracks, etc. do not occur in the hard coat layer even when stretched. Second, scratch resistance is necessary. The hard coat layer of the decorative film is located on the outermost surface when attached to the resin molded product and plays a role in protecting the surface.

Generally, in order to provide scratch resistance to the hard coat layer, a method of increasing surface hardness and providing resistance to external force is adopted, for example, by forming a highly cross-linked structure, that is, forming a cross-linked structure with low molecular mobility. do. As these hard coat layer forming materials, polyfunctional acrylate-based materials that are three-dimensionally crosslinked by radicals are currently most used. However, polyfunctional acrylate-based materials have no stretchability at all due to their high crosslinking density.

On the other hand, in order to provide stretchability to the hard coat layer, for example, a method using a polyfunctional acrylate-based oligomer or a polyfunctional urethane acrylate-based oligomer with a molecular weight of about 1,000 to 10,000 and an acrylate group density adjusted is adopted. do. These multifunctional acrylate-based oligomers have crosslinking sites and stretching sites in their molecular structures, and can exhibit appropriate stretchability due to the molecular mobility of the stretching sites. However, the crosslinking density decreases and the scratch resistance is poor.

In this way, the stretchability and scratch resistance of the hard coat layer are in a trade-off relationship, and making both properties compatible has been a conventional problem.

However, in portable information terminal devices such as mobile phones, humans operate them by holding them with their hands and touching them with their fingers. Accordingly, there is a problem that fingerprints are attached to the body every time it is held by hand, damaging its appearance. Fingerprints contain moisture derived from sweat and oil derived from sebum, and in order to make it difficult for both to adhere, it is strongly desired to impart water and oil repellency to the hard coat layer on the surface of the body.

From this viewpoint, it is desired that the surface of the portable information terminal device has anti-fouling properties against fingerprints and the like. However, even if the initial anti-fouling property reaches a significant level, its function often deteriorates during use because people touch it with their hands every day. Therefore, the durability of antifouling properties during use was an issue.

Conventionally, as a method of imparting antifouling properties to the surface of the hard coat layer, a method of adding a small amount of a fluorine-based surface modifier to the coating liquid forming the hard coat layer has been used. The added fluorine-based compound segregates on the surface of the hard coat layer due to its low surface energy, and provides water and oil repellency. As the fluorine-based compound, from the viewpoint of water repellency and oil repellency, an oligomer with a number average molecular weight of about 1,000 to 5,000 called perfluoropolyether with a poly(oxyperfluoroalkylene) chain is used. However, since perfluoropolyether has a high fluorine concentration, it is difficult to dissolve in the organic solvent usually used in the coating liquid for forming the hard coat layer. Additionally, agglomeration occurs in the formed hard coat layer.

In order to provide such perfluoropolyether with solubility in organic solvents and dispersibility in the hard coat layer, a method of adding organic moieties to the perfluoropolyether is used. Furthermore, in order to provide scratch resistance, a method of bonding an active energy ray-curable moiety represented by a (meth)acrylate group is used.

Until now, as an antifouling hard coat layer with scratch resistance, as a component that imparts antifouling properties to the surface of the hard coat layer, a poly(oxyperfluoroalkylene) chain has a poly(oxyalkylene) group and one at both ends of the chain. A technology using a compound having a (meth)acryloyl group via a urethane bond as a surface modifier is disclosed (Patent Document 1).

International Publication No. 2016/163479

However, even if the surface modifier of Patent Document 1 is added to polyfunctional acrylate-based oligomers for the purpose of providing scratch resistance to the hard coat layer that exhibits stretchability, compatibility is poor due to the high molecular weight and hydrophobicity of these oligomers. It was bad, and there was a problem that the hard coat layer, which was the cured product, became cloudy.

In order to achieve the above object, the present inventors have conducted careful studies and found that, at both ends of the molecular chain containing a poly(oxyperfluoroalkylene) group, a urethane bond is inserted without a poly(oxyalkylene) group. Therefore, the perfluoropolyether having an active energy ray polymerizable group is excellent in solubility in the coating liquid for forming the hard coat layer containing the lactone-modified polyfunctional monomer and in dispersibility in the hard coat layer, and also has excellent dispersibility in the hard coat layer. It was discovered that a curable composition containing this perfluoropolyether and a lactone-modified multifunctional monomer had stretchability and excellent scratch resistance, and was capable of forming a hard coat layer with a transparent appearance, and the present invention was completed. .

That is, the present invention, as a first aspect,

(a) 100 parts by mass of active energy ray-curable lactone-modified multifunctional monomer,

(b) a perfluoropolyether having an active energy ray polymerizable group via a urethane bond at both ends of the molecular chain containing a poly(oxyperfluoroalkylene) group (however, the poly(oxyperfluoroalkylene) (Excluding perfluoropolyether having a poly(oxyalkylene) group between the alkylene) group and the urethane bond.) 0.1 to 10 parts by mass, and

(c) 1 to 20 parts by mass of a polymerization initiator that generates radicals by active energy rays

It relates to a curable composition containing.

As a second aspect, it relates to the curable composition according to the first aspect, in which the (b) perfluoropolyether has at least two active energy ray polymerizable groups at each of both terminals.

As a third aspect, it relates to the curable composition described in the second aspect, wherein the (b) perfluoropolyether has at least three active energy ray polymerizable groups at each of both terminals.

As a fourth aspect, the poly(oxyperfluoroalkylene) group is a group having -[OCF ₂ ]- and -[OCF ₂ CF ₂ ]- as repeating units, according to any one of the first to third aspects. It relates to the curable composition described.

As a fifth aspect, it relates to the curable composition according to the fourth aspect, wherein the (b) perfluoropolyether has a partial structure represented by formula [1].

[Formula 1]

(In the formula, n is the total number of repeating units - [OCF ₂ CF ₂ ]- and the number of repeating units - [OCF ₂ ]-, and represents an integer of 5 to 30.)

As a sixth aspect, the polyfunctional monomer (a) includes at least one selected from the group consisting of lactone-modified polyfunctional (meth)acrylate compounds and lactone-modified polyfunctional urethane (meth)acrylate compounds. It relates to the curable composition according to any one of the first to fifth aspects.

As a seventh aspect, it relates to the curable composition according to any one of the first to sixth aspects, wherein the polyfunctional monomer (a) is an ε-caprolactone modified polyfunctional monomer.

As an eighth aspect, it relates to the curable composition according to any one of the first to seventh aspects, further comprising (d) a solvent.

As a ninth viewpoint, it relates to a cured film obtained from the curable composition according to any one of the first to eighth viewpoints.

As a tenth aspect, it relates to a hard coat film comprising a hard coat layer on at least one side of a film substrate, wherein this hard coat layer is made of the cured film according to the ninth aspect.

As an 11th aspect, it is a hard coat film provided with a hard coat layer on at least one side of a film base, wherein the hard coat layer applies the curable composition according to any one of the 1st to 8th aspects on the film base. It relates to a hard coat film formed by a method including a process of forming a coating film and a process of curing the coating film by irradiating active energy rays.

As a twelfth aspect, it relates to the hard coat film according to the tenth or eleventh aspect, wherein the hard coat layer has a film thickness of 1 to 10 μm.

As a thirteenth aspect, a perfluoropolyether compound having at least three active energy ray polymerizable groups via a urethane bond at each end of the molecular chain containing a poly(oxyperfluoroalkylene) group (provided that , excluding perfluoropolyether compounds having a poly(oxyalkylene) group between the poly(oxyperfluoroalkylene) group and the urethane bond.

As a 14th aspect, the perfluoropolyether compound according to the 13th aspect, wherein the poly(oxyperfluoroalkylene) group is a group having -[OCF ₂ ]- and -[OCF ₂ CF ₂ ]- as repeating units. It's about.

As a 15th aspect, it relates to the perfluoropolyether compound described in the 14th aspect, which has a partial structure represented by formula [1].

[Formula 2]

(In the formula, n is the total number of repeating units - [OCF ₂ CF ₂ ]- and the number of repeating units - [OCF ₂ ]-, and represents an integer of 5 to 30.)

As a sixteenth aspect, it relates to a surface modifier comprising the perfluoropolyether compound according to any one of the thirteenth to fifteenth aspects.

As a seventeenth aspect, it relates to the use of the perfluoropolyether compound according to any one of the thirteenth to fifteenth aspects for surface modification.

According to the present invention, it is possible to provide a curable composition useful for forming cured films and hard coat layers that have excellent scratch resistance, excellent appearance, and extensibility even for thin films with a thickness of about 1 to 10 μm.

In addition, according to the present invention, it is possible to provide a hard coat film whose surface is provided with a cured film obtained from the curable composition or a hard coat layer formed therefrom, and has excellent scratch resistance and appearance and has stretchability. Film can be provided.

<Curable composition>

The curable composition of the present invention is specifically,

(a) 100 parts by mass of active energy ray-curable lactone-modified multifunctional monomer,

(b) a perfluoropolyether having an active energy ray polymerizable group via a urethane bond at both ends of the molecular chain containing a poly(oxyperfluoroalkylene) group (however, the poly(oxyperfluoroalkylene) (Excluding perfluoropolyether having a poly(oxyalkylene) group between the alkylene) group and the urethane bond.) 0.1 to 10 parts by mass, and

(c) 1 to 20 parts by mass of a polymerization initiator that generates radicals by active energy rays

It relates to a curable composition containing.

Hereinafter, each component of (a) to (c) above will first be described.

[(a) Active energy ray-curable lactone-modified multifunctional monomer]

Active energy ray-curable lactone-modified multifunctional monomer refers to a polyfunctional monomer modified with lactone that undergoes a polymerization reaction and hardens by irradiating active energy rays such as ultraviolet rays.

In the curable composition of the present invention, the preferred (a) active energy ray-curable lactone-modified polyfunctional monomer is selected from the group consisting of lactone-modified polyfunctional (meth)acrylate compounds and lactone-modified polyfunctional urethane (meth)acrylate compounds. It is a monomer that becomes

Meanwhile, in the present invention, a (meth)acrylate compound refers to both an acrylate compound and a methacrylate compound. For example, (meth)acrylic acid refers to acrylic acid and methacrylic acid.

Examples of the lactone-modified polyfunctional (meth)acrylate compound include those modified with lactones such as γ-butyrolactone, δ-valerolactone, and ε-caprolactone (i.e., lactones with ring-opened or ring-opened portions). (meth)acrylate compounds of polyol or polythiol (weighted compound) can be mentioned.

Examples of this polyol include trimethylolpropane, ditrimethylolpropane, pentaerythritol, dipentaerythritol, glycerin, bisphenol A, ethoxylated trimethylolpropane, ethoxylated pentaerythritol, ethoxylated dipentaerythritol, and ethoxylated glycerin. , ethoxylated bisphenol A, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, tricyclo[5.2.1.0 ^2,6 ]decanedimethanol, 1,3-adamantanediol, 1,3-adamantanedimethanol, ethylene glycol, diethylene glycol, triethylene glycol, Tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, neopentyl glycol, dioxane glycol, bis(2-hydroxyethyl)isocyanurate, tris(2-hydroxyethyl)isocyanurate late, 9,9-bis(4-hydroxyphenyl)fluorene, 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene, etc.

Additionally, examples of this thiol include bis(2-mercaptoethyl)sulfide, bis(4-mercaptophenyl)sulfide, and the like.

Such lactone-modified polyfunctional (meth)acrylate compounds include, for example, lactone-modified trimethylolpropane tri(meth)acrylate, lactone-modified ditrimethylolpropane tetra(meth)acrylate, and lactone-modified pentaerythritol di(meth)acrylate. ) Acrylate, lactone-modified pentaerythritol tri(meth)acrylate, lactone-modified pentaerythritol tetra(meth)acrylate, lactone-modified dipentaerythritol penta(meth)acrylate, lactone-modified dipentaerythritol hexa(meth)acrylate, Lactone-modified 2-hydroxy-1,3-di(meth)acryloyloxypropane, lactone-modified 2-hydroxy-1-acryloyloxy-3-methacryloyloxypropane, lactone-modified glycerin tri(meth) ) Acrylate, lactone-modified bisphenol A di(meth)acrylate, lactone-modified ethoxylated trimethylolpropane tri(meth)acrylate, lactone-modified ethoxylated pentaerythritol tetra(meth)acrylate, lactone-modified ethoxylated di(meth)acrylate. Pentaerythritol hexa(meth)acrylate, lactone-modified ethoxylated glycerin tri(meth)acrylate, lactone-modified ethoxylated bisphenol A di(meth)acrylate, lactone-modified 1,3-propanediol di(meth)acrylate. , Lactone-modified 1,3-butanediol di(meth)acrylate, Lactone-modified 1,4-butanediol di(meth)acrylate, Lactone-modified 1,6-hexanediol di(meth)acrylate, Lactone-modified 2-methyl- 1,8-octanediol di(meth)acrylate, lactone-modified 1,9-nonanediol di(meth)acrylate, lactone-modified 1,10-decanediol di(meth)acrylate, lactone-modified tricyclo [5.2. 1.0 ^2,6 ]Decanedimethanol di(meth)acrylate, lactone-modified 1,3-adamantane diol di(meth)acrylate, lactone-modified 1,3-adamantane dimethanol di(meth)acrylate, lactone Modified ethylene glycol di(meth)acrylate, lactone-modified diethylene glycol di(meth)acrylate, lactone-modified triethylene glycol di(meth)acrylate, lactone-modified tetraethylene glycol di(meth)acrylate, lactone-modified polyethylene glycol Di(meth)acrylate, lactone-modified propylene glycol di(meth)acrylate, lactone-modified dipropylene glycol di(meth)acrylate, lactone-modified polypropylene glycol di(meth)acrylate, lactone-modified neopentyl glycol di(meth)acrylate ) Acrylate, lactone-modified dioxane glycol di(meth)acrylate, lactone-modified bis(2-hydroxyethyl)isocyanurate di(meth)acrylate, lactone-modified tris(2-hydroxyethyl)isocyanurate Late tri(meth)acrylate, lactone-modified 9,9-bis(4-(meth)acryloyloxyphenyl)fluorene, lactone-modified 9,9-bis[4-(2-(meth)acryloyloxy) Examples include ethoxy)phenyl]fluorene, lactone-modified bis[2-(meth)acryloylthioethyl]sulfide, and lactone-modified bis[4-(meth)acryloylthiophenyl]sulfide.

Among these, ε-caprolactone is preferable as the lactone to be modified, and for example, a compound in which the lactone of the lactone-modified polyfunctional (meth)acrylate compound is ε-caprolactone is preferable.

More preferable lactone-modified polyfunctional (meth)acrylate compounds include, for example, ε-caprolactone-modified pentaerythritol tri(meth)acrylate, ε-caprolactone-modified pentaerythritol tetra(meth)acrylate, and ε-caprolactone. Lactone-modified dipentaerythritol penta(meth)acrylate, ε-caprolactone-modified dipentaerythritol hexa(meth)acrylate, etc. can be mentioned.

The lactone-modified polyfunctional urethane (meth)acrylate compound has a plurality of (meth)acryloyl groups in one molecule, a urethane bond (-NHCOO-), and, for example, γ-butyrolactone, δ-vale It is a compound having the ring-opening structure of lactones such as rolactone and ε-caprolactone.

For example, the lactone-modified polyfunctional urethane (meth)acrylate includes those obtained by reaction between polyfunctional isocyanate and (meth)acrylate having a hydroxy group modified with lactone, and polyfunctional isocyanate having a hydroxy group. Examples include those obtained by reaction between (meth)acrylate and polyol modified with lactone, but the lactone-modified polyfunctional urethane (meth)acrylate compound usable in the present invention is not limited to these examples.

Meanwhile, examples of the polyfunctional isocyanate include tolylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, and hexamethylene diisocyanate.

Additionally, (meth)acrylates having the hydroxy group include, for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, pentaerythritol tri(meth)acrylate, and dipentaerythritol. Penta(meth)acrylate, tripentaerythritol hepta(meth)acrylate, etc. can be mentioned.

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; polyetherpolyol; Polycarbonate diol, etc. can be mentioned.

In the present invention, as the active energy ray-curable lactone-modified polyfunctional monomer (a), one type is selected from the group consisting of the lactone-modified polyfunctional (meth)acrylate compound and the lactone-modified polyfunctional urethane (meth)acrylate compound. It can be used alone or in combination of two or more types.

[(b) A perfluoropolyether having an active energy ray polymerizable group via a urethane bond at both ends of the molecular chain containing a poly(oxyperfluoroalkylene) group (however, the poly(oxyperfluoroalkylene) [Excluding perfluoropolyethers having a poly(oxyalkylene) group between the (roalkylene) group and the urethane bond.)]

In the present invention, as component (b), an active energy ray polymerizable group is formed at both ends of the molecular chain containing a poly(oxyperfluoroalkylene) group through a urethane bond rather than through a poly(oxyalkylene) group. A perfluoropolyether having a (hereinafter also simply referred to as “(b) a perfluoropolyether having a polymerizable group at both ends”) is used. Component (b) serves as a surface modifier in the hard coat layer to which the curable composition of the present invention is applied.

In addition, component (b) has excellent compatibility with component (a), thereby suppressing clouding of the hard coat layer and enabling the formation of a hard coat layer with a transparent appearance.

Meanwhile, the above-mentioned poly(oxyalkylene) group refers to a group in which the number of repeating units of the oxyalkylene group is 2 or more and the alkylene group in the oxyalkylene group is an unsubstituted alkylene group.

The number of carbon atoms of the alkylene group in the poly(oxyperfluoroalkylene) group is not particularly limited, but is preferably 1 to 4 carbon atoms. That is, the poly(oxyperfluoroalkylene) group refers to a group having a structure in which divalent fluorocarbon groups having 1 to 4 carbon atoms and oxygen atoms are alternately connected, and the oxyperfluoroalkylene group has 2 fluorocarbon groups having 1 to 4 carbon atoms. It refers to a group that has a structure in which a fluorocarbon group and an oxygen atom are connected. Specifically, -[OCF ₂ ]-(oxyperfluoromethylene group), -[OCF ₂ CF ₂ ]-(oxyperfluoroethylene group), -[OCF ₂ CF ₂ CF ₂ ]-(oxyperfluoro Groups such as propane-1,3-diyl group) and -[OCF ₂ C(CF ₃ )F]-(oxyperfluoropropane-1,2-diyl group) can be mentioned.

The oxyperfluoroalkylene group may be used individually, or two or more types may be used in combination. In that case, the bond of multiple kinds of oxyperfluoroalkylene groups may be a block bond or a random bond. It could be either.

Among these, from the viewpoint of obtaining a cured film with excellent scratch resistance, as the poly(oxyperfluoroalkylene) group, -[OCF ₂ ]-(oxyperfluoromethylene group) and -[OCF ₂ CF ₂ ]-( It is preferable to use a group having both oxyperfluoroethylene groups as repeating units.

Among these, as the poly(oxyperfluoroalkylene) group, repeating units: -[OCF ₂ ]- and -[OCF ₂ CF ₂ ]- are in a molar ratio of [repeating units: -[OCF ₂ ]-]: [Repeating unit: -[OCF ₂ CF ₂ ]-] It is preferable that it is a group included in a ratio of 2:1 to 1:2, and it is more preferable that it is a group included in a ratio of about 1:1. The combination of these repeating units may be either a block combination or a random combination.

The number of repeating units of the oxyperfluoroalkylene group is preferably in the range of 5 to 30, more preferably in the range of 7 to 21, in terms of the total number of repeating units.

In addition, the weight average molecular weight (Mw) of the poly(oxyperfluoroalkylene) group measured in terms of polystyrene by gel permeation chromatography is 1,000 to 5,000, preferably 1,500 to 2,000.

Examples of the active energy ray polymerizable group bonded via the urethane bond include (meth)acryloyl group, urethane (meth)acryloyl group, and vinyl group.

(b) The perfluoropolyether having a polymerizable group at both terminals is not limited to having one active energy ray polymerizable group such as a (meth)acryloyl group at both ends, but two or more active energy ray polymerizable groups. may have at both terminals, and for example, terminal structures containing an active energy ray polymerizable group include the structures of A1 to A5 shown below, and those in which the acryloyl group in these structures is replaced with a methacryloyl group. structure can be mentioned.

[Formula 3]

Examples of such (b) perfluoropolyether having polymerizable groups at both terminals include a compound represented by the following formula [2].

[Formula 4]

(In the formula, A represents one of the structures represented by the above formulas [A1] to formula [A5] and structures in which an acryloyl group in these structures is replaced with a methacryloyl group, and PFPE is the poly(oxyperfluoroyl group) (However, the side directly bonded to L ¹ is the oxy terminal, and the side bonded to the oxygen atom is the perfluoro alkylene terminal.), and L ¹ is substituted with 1 to 3 fluorine atoms. represents an alkylene group having 2 to 3 carbon atoms, m each independently represents an integer of 1 to 5, and L ² represents an m+1-valent residue excluding OH from the m+1-valent alcohol.)

The alkylene group having 2 to 3 carbon atoms substituted with 1 to 3 fluorine atoms includes CH ₂ CHF, CH ₂ CF ₂ , CHFCF ₂ , CH ₂ CH ₂ CHF, CH ₂ CH ₂ CF ₂ , CH ₂ CHFCF _2, etc. may be mentioned, and CH ₂ CF ₂ is preferable.

The partial structure (A-NHC(=O)O) _m L ² - in the compound represented by the above formula [2] includes structures represented by the formulas [B1] to [B12] shown below, etc. there is.

[Formula 5]

[Formula 6]

(In the formula, A represents one of the structures represented by the formulas [A1] to [A5] and structures in which an acryloyl group in these structures is replaced with a methacryloyl group.)

Among the structures represented by the formulas [B1] to [B12], formulas [B1] and formulas [B2] correspond to the case where m = 1, and formulas [B3] to formulas [B6] correspond to the case where m = 2. Corresponds to , Equations [B7] to Equations [B9] correspond to the case of m = 3, and Equations [B10] to Equations [B12] correspond to the case of m = 5.

Among these, the structure represented by the formula [B3] is preferable, and the combination of the formula [B3] and the formula [A3] is especially preferable.

Preferred perfluoropolyethers having polymerizable groups at both terminals (b) include compounds having a partial structure represented by formula [1].

[Formula 7]

The partial structure represented by formula [1] corresponds to the portion excluding A-NHC (=O) from the compound represented by formula [2].

n in formula [1] represents the total number of the number of repeating units - [OCF ₂ CF ₂ ] - and the number of repeating units - [OCF ₂ ] -, and is preferably an integer in the range of 5 to 30, 7 An integer in the range of ~21 is more preferable. In addition, the ratio between the number of repeating units - [OCF ₂ CF ₂ ] - and the number of repeating units - [OCF ₂ ] - is preferably in the range of 2:1 to 1:2, and is about 1:1. It is more preferable to set it as a range. The combination of these repeating units may be either a block combination or a random combination.

In the present invention, the perfluoropolyether (b) having a polymerizable group at both terminals is preferably 0.1 to 10 parts by mass, based on 100 parts by mass of the above-mentioned (a) active energy ray-curable lactone-modified polyfunctional monomer. It is preferable to use it in a ratio of 0.2 to 5 parts by mass.

The perfluoropolyether having a polymerizable group at both ends (b) is, for example, of the following formula [3]

[Formula 8]

(wherein PFPE, L ¹ , L ² and m have the same meaning as above). An isocyanate compound having a polymerizable group with respect to the hydroxy groups present at both terminals of the compound represented by, that is, the formula above. Structures represented by formulas [A1] to [A5] and compounds in which an isocyanato group is bonded to the bond number in the structures in which the acryloyl group in these structures is replaced with a methacryloyl group (for example, It can be obtained by reacting 2-(meth)acryloyloxyethyl isocyanate, 1,1-bis((meth)acryloyloxymethyl)ethyl isocyanate, etc.) to form a urethane bond.

Meanwhile, the curable composition of the present invention includes a perfluoropolyether (b) having an active energy ray polymerizable group via a urethane bond at both ends of the molecular chain containing a poly(oxyperfluoroalkylene) group (however, , there is no poly(oxyalkylene) group between the poly(oxyperfluoroalkylene) group and the urethane bond), in addition to the urethane bond at one end of the molecular chain containing the poly(oxyperfluoroalkylene) group. Through, a perfluoropolyether having an active energy ray polymerizable group and a hydroxy group at the other end (provided, that between the poly(oxyperfluoroalkylene) group and the urethane bond and the poly(oxyperfluoromethylene) (does not have a poly(oxyalkylene) group between the (roalkylene) group and the hydroxy group) or a molecular chain containing a poly(oxyperfluoroalkylene) group as represented by the above formula [3] Perfluoropolyether having hydroxy groups at both ends (however, it does not have a poly(oxyalkylene) group between the poly(oxyperfluoroalkylene) group and the hydroxy group.) [Has an active energy ray polymerizable group. Compounds that are not present] may be included.

The present invention also provides a perfluoropolyether compound having at least three active energy ray polymerizable groups via a urethane bond at each end of the molecular chain containing a poly(oxyperfluoroalkylene) group (however, , excluding perfluoropolyether compounds having a poly(oxyalkylene) group between the poly(oxyperfluoroalkylene) group and the urethane bond.).

As the above-described perfluoropolyether compound having polymerizable groups at both terminals, a compound having a partial structure represented by the above formula [1] is preferable.

As described above, the perfluoropolyether compound of the present invention has excellent compatibility with component (a), thereby suppressing clouding of the hard coat layer and forming a transparent appearance of the hard coat layer. It shows excellent effects in enabling formation.

The present invention also relates to a surface modifier consisting of the above-mentioned perfluoropolyether compound, and the use of this perfluoropolyether compound for surface modification.

[(c) Polymerization initiator that generates radicals by active energy rays]

In the curable composition of the present invention, a polymerization initiator that generates radicals by active energy rays (hereinafter also simply referred to as “(c) polymerization initiator”) is preferably used by active energy rays such as electron beams, ultraviolet rays, and X-rays. It is a polymerization initiator that generates radicals, especially when irradiated with ultraviolet rays.

The polymerization initiator (c) includes, for example, benzoins, alkylphenones, thioxanthone, azones, azides, diazides, o-quinonediazides, acylphosphine oxides, oxime esters, and organic Peroxides, benzophenones, biscumarins, bisimidazoles, titanocenes, thiols, halogenated hydrocarbons, trichloromethyltriazines, or onium salts such as iodonium salts and sulfonium salts. These may be used individually or in combination of two or more types.

Among these, in the present invention, it is preferable to use alkylphenones as the (c) polymerization initiator from the viewpoints of transparency, surface hardenability, and thin film hardenability. By using alkylphenones, a cured film with improved scratch resistance can be obtained.

Examples of the alkylphenones include 1-hydroxycyclohexyl=phenyl=ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2-hydroxy-1-(4- (2-hydroxyethoxy)phenyl)-2-methylpropan-1-one, 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)- α-hydroxyalkylphenones such as 2-methylpropan-1-one; 2-methyl-1-(4-(methylthio)phenyl)-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butan-1- α-aminoalkylphenones such as onone; 2,2-dimethoxy-1,2-diphenylethan-1-one; Methyl phenylglyoxylate, etc. are mentioned.

In the present invention, the (c) polymerization initiator is used in a ratio of 1 to 20 parts by mass, preferably 2 to 10 parts by mass, based on 100 parts by mass of the above-mentioned (a) active energy ray-curable lactone-modified polyfunctional monomer. It is desirable.

[(d) Solvent]

The curable composition of the present invention may further contain a (d) solvent, that is, it may be in the form of a varnish (film-forming material).

The solvent can be selected appropriately by dissolving the above-mentioned components (a) to (c) and taking into account workability during coating and drying properties before and after curing required for forming a cured film (hard coat layer), which will be described later. Examples include aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, and tetralin; Aliphatic or alicyclic hydrocarbons such as n-hexane, n-heptane, mineral spirit, and cyclohexane; Halogenates such as methyl chloride, methyl bromide, methyl iodide, dichloromethane, chloroform, carbon tetrachloride, trichlorethylene, perchlorethylene, and o-dichlorobenzene; Esters or ester ethers such as ethyl acetate, butyl acetate, methoxybutyl acetate, methyl cellosolve acetate, ethyl cellosolve acetate, and propylene glycol monomethyl ether acetate; Diethyl ether, tetrahydrofuran, 1,4-dioxane, methyl cellosolve, ethyl cellosolve, butyl cellosolve, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether. , ethers such as propylene glycol monoisopropyl ether and propylene glycol mono-n-butyl ether; Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, 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, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone; Sulfoxides such as dimethyl sulfoxide, and mixed solvents of two or more of these can be mentioned.

The amount of these (d) solvents used is not particularly limited, but for example, they are used at a concentration such that the solid content concentration in the curable composition of the present invention is 1 to 70% by mass, preferably 5 to 50% by mass. Here, the solid content concentration (also referred to as non-volatile content concentration) refers to the solid content (solvent in all components) relative to the total mass (total mass) of the components (a) to (d) (and other additives as necessary) of the curable composition of the present invention. Indicates the content (excluding ingredients).

[Other additives]

In addition, the curable composition of the present invention includes additives generally added as needed, as long as they do not impair the effect of the present invention, such as polymerization inhibitors, photosensitizers, leveling agents, surfactants, adhesion imparting agents, Plasticizers, ultraviolet absorbers, antioxidants, storage stabilizers, antistatic agents, inorganic fillers, pigments, dyes, etc. may be appropriately mixed.

<Curated film>

The curable composition of the present invention can be applied (coated) on a substrate to form a coating film, and then irradiated with active energy rays to polymerize (cure) the coating film, thereby forming a cured film. This cured film is also the subject of the present invention. Additionally, the hard coat layer in the hard coat film described later can be made of this cured film.

The substrate in this case includes, for example, various resins (polycarbonate, polymethacrylate, polystyrene, polyester such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyolefin, polyamide, polyimide, etc. , epoxy resin, melamine resin, triacetylcellulose, acrylonitrile-butadiene-styrene copolymer (ABS), acrylonitrile-styrene copolymer (AS), norbornene resin, etc.), metal, wood, paper, glass, slate etc. can be mentioned. The shape of these substrates may be plate-shaped, film-shaped, or three-dimensionally molded.

Application methods on the substrate include cast coating, spin coating, blade coating, dip coating, roll coating, spray coating, bar coating, die coating, inkjet printing, and printing methods (convex plate, intaglio plate). , flatbed, screen printing, etc.) can be appropriately selected, and among these, the roll-to-roll method can be used, and from the viewpoint of thin film applicability, the convex printing method, especially the gravure coat, can be used. It is desirable to use the law. Meanwhile, it is preferable to filter the curable composition in advance using a filter with a pore diameter of about 0.2 μm, and then apply it for application. On the other hand, when applying, if necessary, a solvent may be added to this curable composition to form a varnish. Solvents in this case include various solvents mentioned in [(d) solvent] described above.

After applying the curable composition on a substrate to form a coating film, if necessary, the coating film is pre-dried in a hot plate or oven to remove the solvent (solvent removal process). The conditions for heat drying at this time are preferably, for example, 40 to 120°C for about 30 seconds to 10 minutes.

After drying, the coating film is cured by irradiating active energy rays such as ultraviolet rays. Active energy rays include ultraviolet rays, electron rays, and X-rays, and ultraviolet rays are particularly preferable. Light sources used for ultraviolet irradiation include solar rays, chemical lamps, low-pressure mercury lamps, high-pressure mercury lamps, metal halide lamps, xenon lamps, and UV-LEDs.

Additionally, polymerization can also be completed afterward by performing post-bake, specifically by heating using a hot plate, oven, etc.

On the other hand, the thickness of the cured film formed after drying and curing is usually 0.01 to 50 μm, preferably 0.05 to 20 μm.

<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 manufactured. This hard coat film is also the object of the present invention, and this hard coat film is suitably used to protect the surfaces of various display elements such as touch panels and liquid crystal displays, for example.

The hard coat layer in the hard coat film of the present invention is formed by applying the curable composition of the present invention described above on a film substrate to form a coating film, and irradiating the coating film with active energy rays such as ultraviolet rays to form the coating film. It can be formed by a method including a process of hardening.

As the film substrate, among the substrates mentioned in the above-mentioned <cured film>, various transparent resin films that can be used for optical purposes are used. Preferably, for example, polyester such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polycarbonate, polymethacrylate, polystyrene, polyolefin, polyamide, polyethylene Resin films selected from mead, triacetylcellulose, etc. can be mentioned.

In addition, the method of applying the curable composition on the film substrate (coating film forming process) and the method of irradiating the coating film with active energy rays (curing process) can be the methods mentioned in <Curated Film> described above. In addition, when the curable composition of the present invention contains a solvent (in the form of a varnish), after the coating film forming process, a step of drying the coating film and removing the solvent may be included, if necessary. In that case, the drying method (solvent removal process) of the coating film mentioned in the above-mentioned <cured film> can be used.

The film thickness of the hard coat layer obtained in this way is preferably 1 to 20 μm, more preferably 1 to 10 μm.

[Example]

Hereinafter, the present invention will be described in more detail through examples, but the present invention is not limited to the following examples.

Meanwhile, in the examples, the equipment and conditions used for sample preparation and physical property analysis are as follows.

(1) Barcoat application

Device: SMT Co., Ltd. PM-9050MC

Bar: A-Bar OSP-22 manufactured by OSG System Products Co., Ltd., maximum wet film thickness 22μm (equivalent to wire bar #9)

Application speed: 4m/min

(2) Oven

Device: Dust-free dryer DRC433FA manufactured by Advantec Toyo Co., Ltd.

(3) UV curing

Device: CV-110QC-G manufactured by Heraeus Co., Ltd.

Lamp: High-pressure mercury lamp H-bulb manufactured by Heraeus Co., Ltd.

(4) Gel permeation chromatography (GPC)

Device: HLC-8220GPC manufactured by Tosoh Corporation

Column: Showa Denko Co., Ltd. Shodex (registered trademark) GPC K-804L, GPC K-805L

Column temperature: 40℃

Eluent: tetrahydrofuran

Detector: RI

(5) Scratch test

Equipment: Reciprocating abrasion tester manufactured by Haydon Science Co., Ltd. TRIBOGEAR TYPE: 30S

Scanning speed: 3,000 mm/min

Scanning distance: 50mm

(6) Total light transmittance, haze

Device: Haze meter NDH5000 manufactured by Nippon Denshoku Kogyo Co., Ltd.

(7) Contact angle

Device: DropMaster DM-501 manufactured by Kyowa Interface Science Co., Ltd.

Measurement temperature: 20℃

(8) Tensile test

Device: Autograph AGS-10kNX, tabletop precision universal testing machine manufactured by Shimadzu Works Co., Ltd.

Gripping tool (つかみ具): 1kN manual screw type flat gripping tool

Gripping teeth: High-strength rubber coated grinding teeth

Tensile speed: 20mm/min

Measurement temperature: 20℃

In addition, the abbreviated symbols indicate the following meanings.

PFPE1: Perfluoropolyether having two hydroxy groups at each end without a poly(oxyalkylene) group (Fomblin (registered trademark) T4 manufactured by Solbase Specialty Polymers)

PFPE2: Perfluoropolyether having hydroxy groups through poly(oxyalkylene) groups (repeating unit number 8 to 9) at both ends (Fluorolink 5147X manufactured by Solbase Specialty Polymers)

SM2: Perfluoropolyether having two methacryloyl groups with urethane bonds at each end (Fomblin (registered trademark) MT70, manufactured by Solbase Specialty Polymers, Inc., 80% by mass MEK solution)

BEI: 1,1-bis(acryloyloxymethyl)ethyl isocyanate [Karenz (registered trademark) BEI, manufactured by Showa Denko Co., Ltd.]

DOTDD: Dioctyltin dineodecanoate [Neostane (registered trademark) U-830 manufactured by Nitto Chemical Co., Ltd.]

DPCL: Caprolactone modified dipentaerythritol hexaacrylate [KAYARAD DPCA-60 manufactured by Nippon Explosives Co., Ltd.]

DPHA: Dipentaerythritol pentaacrylate/dipentaerythritol hexaacrylate mixture [KAYARAD DPHA manufactured by Nippon Explosives Co., Ltd.]

PETA: Pentaerythritol triacrylate/pentaerythritol tetraacrylate mixture [NK ester A-TMM-3LM-N manufactured by Shin Nakamura Chemical Co., Ltd.]

I2959: 2-Hydroxy-1-(4-(2-hydroxyethoxy)phenyl)-2-methylpropan-1-one [IRGACURE (registered trademark) 2959, manufactured by BASF Japan Co., Ltd.]

MEK: Methyl ethyl ketone

PGME: propylene glycol monomethyl ether

[Example 1] Preparation of perfluoropolyether (SM1) having four acryloyl groups through urethane bonds at both ends.

Into the screw tube, 1.19 g (0.5 mmol) of PFPE1, 0.52 g (2.0 mmol) of BEI, 0.017 g of DOTDD (0.01 times the total mass of PFPE1 and BEI), and 1.67 g of MEK were added. This mixture was stirred at room temperature (about 23°C) for 24 hours using a stirrer chip to obtain a 50% by mass MEK solution of the target compound SM1.

The weight average molecular weight of the obtained SM1 measured in polystyrene conversion by GPC: Mw was 3,000, and the dispersion degree: Mw (weight average molecular weight)/Mn (number average molecular weight) was 1.2.

[Preparation Example 1] Preparation of 50% by mass MEK solution of SM2

Into the screw tube, 2.5 g of SM2 and 1.5 g of MEK were added. This mixture was stirred at room temperature (about 23°C) for 24 hours using a stirrer chip to obtain a 50% by mass MEK solution of SM2.

[Comparative Preparation Example 1] Preparation of perfluoropolyether (SM3) having two acryloyl groups through a poly(oxyalkylene) group at each end and one urethane bond.

Into the screw tube, 1.05 g (0.5 mmol) of PFPE2, 0.26 g (1.0 mmol) of BEI, 0.013 g of DOTDD (0.01 times the total mass of PFPE2 and BEI), and 1.30 g of MEK were added. This mixture was stirred at room temperature (about 23°C) for 24 hours using a stirrer chip to obtain a 50% by mass MEK solution of SM3, the target compound.

The weight average molecular weight of the obtained SM3 measured in polystyrene conversion by GPC: Mw was 3,100, and the dispersion degree: Mw/Mn was 1.1.

[Examples 2 and 3, Comparative Examples 1 to 3]

The following components were mixed according to the description in Table 1, and a curable composition having the solid concentration shown in Table 1 was prepared. Meanwhile, solid content here refers to components other than the solvent. In addition, in the table, [part] indicates [part by mass].

(1) Multifunctional monomer: 100 parts by mass of the polyfunctional monomer listed in Table 1

(2) Surface modifier: Surface modifier listed in Table 1 in the amount shown in Table 1 (converted to solid content)

(3) Polymerization initiator: 5 parts by mass of I2959

(4) Solvent: PGME 158 parts by mass

This curable composition was applied as a bar coat on an A4 size double-sided easily adhesive PET film (Lumiror (trademark registered) U403 manufactured by Toray Co., Ltd., thickness 100 μm) to obtain a coating film. This coating film was dried in an oven at 120°C for 3 minutes to remove the solvent. The obtained film was exposed to UV light at an exposure dose of 300 mJ/cm ² under a nitrogen atmosphere to produce a hard coat film having a hard coat layer (cured film) with a film thickness of about 5 μm.

The homogeneity of each curable composition, and the appearance, scratch resistance, elongation, total light transmittance, haze, and water contact angle of the obtained hard coat film were evaluated. The evaluation procedures for composition homogeneity, appearance, scratch resistance, elongation, and contact angle are shown below. The results are shown together in Table 2.

[Composition homogeneity]

The appearance of the curable composition 2 hours after preparation was visually confirmed and evaluated according to the following standards.

A: Transparent solution

C: White turbidity

[Exterior]

The appearance of the hard coat film was visually confirmed and evaluated according to the following standards.

A: Transparent and stain-free across the entire hard coat layer.

C: The entire hard coat layer becomes cloudy and stains are visible.

[Scratch resistance]

The surface of the hard coat layer was rubbed with steel wool (Bornstar (registered trademark) #0000 (ultrafine) manufactured by Bonestar Sales Co., Ltd.) attached to a reciprocating abrasion tester for 2,000 cycles under a load of 250 g/cm ² to check the degree of scratches. It was visually confirmed and evaluated according to the following standards. On the other hand, when actual use as a hard coat layer is assumed, at least B is required, and A is preferable.

A: No scratches

B: Faintly scratched

C: Scratches on the front

[Stretchability]

The hard coat film was cut into a rectangle with a length of 80 mm and a width of 10 mm, and a test piece was produced. Attach to the gripping tool of the universal testing machine to grip 20mm from both ends in the longitudinal direction of the test piece, and the elongation (= (increase in distance between gripping tools) ÷ (distance between gripping tools) × 100) is 5%, 10%, 15%, 20%. A tensile test was performed to ensure that %. The maximum elongation at which no cracks occurred in the hard coat layer of the test piece was evaluated as elongation.

[Contact angle]

1 μL of water was attached to the surface of the hard coat layer, the contact angle θ after 5 seconds was measured at 5 points, and the average value was taken as the contact angle value.

[Table 1]

[Table 2]

As shown in Table 1, in the hard coat layer, lactone-modified acrylate was used as a multifunctional monomer, and perfluoropolyether SM1 (which has four acryloyl groups through urethane bonds at both ends) was used as a surface modifier. The curable composition using Example 2) or perfluoropolyether SM2 (Example 3), which has two methacryloyl groups via urethane bonds at each end, respectively, shows a transparent solution, and also has this curing property. The hard coat film produced using the composition had excellent scratch resistance, moderate stretchability, and a transparent and stain-free appearance.

On the other hand, in Comparative Example 2, which used perfluoropolyether SM3, which has two acryloyl groups through a poly(oxyalkylene) group at each end and one urethane bond at both ends as a surface modifier, the composition became cloudy and was not homogeneous. It was inferior, and the hard coat layer obtained from this composition had a worse haze compared to the Examples and had a cloudy appearance.

In addition, Comparative Example 1, which used acrylate that was not lactone-modified as a polyfunctional monomer and SM1 as a surface modifier, resulted in no stretchability at all.

As shown in the results of the examples above, a hard coat film that satisfies all of scratch resistance, elongation, and appearance can be produced by using a curable composition combining a lactone-modified multifunctional monomer and a specific perfluoropolyether. You can get it.

Claims (3)

A perfluoropolyether compound having at least two active energy ray polymerizable groups via a urethane bond at each end of the molecular chain containing a poly(oxyperfluoroalkylene) group (however, the poly(oxyperfluoroalkylene) group (Excluding perfluoropolyether compounds having a poly(oxyalkylene) group between the perfluoroalkylene) group and the urethane bond.)
The poly(oxyperfluoroalkylene) group is a group having -[OCF ₂ ]- and -[OCF ₂ CF ₂ ]- as repeating units,
The perfluoropolyether compound has a partial structure represented by formula [1] and is a compound represented by formula [2].

(In formula [1], n is the sum of the number of repeating units - [OCF ₂ CF ₂ ] - and the number of repeating units - [OCF ₂ ]-, and represents an integer of 5 to 30.)

(In formula [2], A represents one of the structures represented by formulas [A1] to formula [A5] and structures in which an acryloyl group in these structures is replaced with a methacryloyl group, and PFPE is the poly(oxy (perfluoroalkylene) group (however, the side directly bonded to L ¹ is the oxy terminal, and the side bonded to the oxygen atom is the perfluoro alkylene terminal.), and L ¹ is substituted with 1 to 3 fluorine atoms. represents an alkylene group with 2 or 3 carbon atoms, and the partial structure (A-NHC(=O)O) _m L ² - represents the structure represented by the formula [B3].)
A surface modifier comprising the perfluoropolyether compound according to claim 1. A method of using the perfluoropolyether compound according to claim 1 for surface modification.