KR20200046037A - Curable composition for stretchable abrasion resistant coating - Google Patents

Abstract

[Problem] A material for forming a hard coat layer having stretchability and excellent scratch resistance and exhibiting a transparent appearance is provided.
[Solutions] (a) 100 parts by mass of active energy ray-curable lactone-modified polyfunctional monomer, (b) active energy through urethane bonds at both ends of a molecular chain containing poly (oxyperfluoroalkylene) groups Perfluoropolyether having a linear polymerizable group (However, except for the perfluoropolyether having a poly (oxyalkylene) group between the poly (oxyperfluoroalkylene) group and the urethane bond) 0.1 to 10 A hard coat film comprising a curable composition comprising a mass part, and (c) 1 to 20 parts by mass of a polymerization initiator that generates radicals by an active energy ray, and a hard coat layer formed from the composition.

Description

Curable composition for stretchable abrasion resistant coating

The present invention relates to a curable composition useful as a material for forming a hard coat layer applied to surfaces of various display elements such as touch panel displays and liquid crystal displays. Specifically, the present invention relates to a curable composition capable of forming a hard coat layer having stretchability and excellent scratch resistance and exhibiting a transparent appearance.

Resin molded products are widely used in portable information terminals such as mobile phones and tablet computers, notebook personal computers, home appliances, and automobile interior and exterior parts. In order to improve the designability of these resin molded products, usually, after molding the resin, the surface is decorated with printing or the like. Recently, as a decorating method for the three-dimensional surface of the resin molded article, a decorating film having a hard coat layer on one side of the film and a printing layer or adhesive layer on the other side was used, and these decorating films were used. , A method of sticking to a resin molded article through an adhesive layer has been studied.

As a required characteristic of the decorative film, first, moldability is required. In other words, stretchability that can follow a three-dimensional surface that does not cause cracks or the like on the hard coat layer even when stretched is required. Second, scratch resistance is required. The hard coat layer of the decorative film is located on the outermost surface in a state attached to the resin molded article, and serves to protect the surface.

In general, to impart abrasion resistance to the hard coat layer, for example, by forming a highly crosslinked structure, that is, by forming a crosslinked structure with low molecular mobility, a method of increasing surface hardness and imparting resistance to external forces is employed. do. As these hard coat layer forming materials, polyfunctional acrylate-based materials that are three-dimensionally crosslinked by radicals are currently used. However, the polyfunctional acrylate-based material has no stretchability due to its high crosslinking density.

On the other hand, in order to impart stretchability to the hard coat layer, for example, a method using a polyfunctional acrylate oligomer having a molecular weight of about 1,000 to 10,000, or a polyfunctional urethane acrylate oligomer having an adjusted acrylate group density is employed. do. These polyfunctional acrylate oligomers have a crosslinking site and a stretching site in the molecular structure, and it is possible to express appropriate stretchability by the molecular mobility of the stretching site. However, the crosslinking density decreases and the scratch resistance is poor.

As described above, the stretchability and scratch resistance of the hard coat layer are in a trade-off relationship, and it has been a conventional problem to achieve both characteristics.

By the way, in a portable information terminal device represented by a mobile phone, a human is operated by holding it with a hand and touching it with a finger. Accordingly, there is a problem that the fingerprint adheres to the ore body every time it is lifted by hand, and its appearance is damaged. The fingerprint contains moisture derived from sweat and oil derived from sebum, and it is strongly desired to impart water-repellent and oil-repellent properties to the hard coat layer on the surface of the ore body in order to make them difficult to adhere to.

From such a viewpoint, it is desired that the surface of the optical body of the portable information terminal device has antifouling properties against fingerprints and the like. However, even if the initial antifouling property reaches a considerable level, the function is often deteriorated during use because a person touches it by hand every day. Therefore, the durability of antifouling properties in the course of use has been a challenge.

Conventionally, as a method of imparting antifouling property 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 is segregated on the surface of the hard coat layer by its low surface energy, and water repellency and oil repellency are imparted. As a fluorine-based compound, from the viewpoint of water repellency and oil repellency, an oligomer having a number average molecular weight of about 1,000 to 5,000 called perfluoropolyether having a poly (oxyperfluoroalkylene) chain is used. However, since the perfluoropolyether has a high fluorine concentration, it is usually difficult to dissolve in the organic solvent used in the coating liquid forming the hard coat layer. In addition, aggregation is caused in the formed hard coat layer.

In order to impart solubility to an organic solvent and dispersibility in a hard coat layer to such a perfluoropolyether, a technique of adding an organic site to a perfluoropolyether is used. Furthermore, in order to impart scratch resistance, a technique of bonding an active energy ray-curable site represented by a (meth) acrylate group is used.

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

International Publication No. 2016/163479

However, even if the surface modifier of Patent Document 1 is added to a polyfunctional acrylate oligomer or the like for the purpose of imparting scratch resistance to a hard coat layer expressing stretchability, compatibility is 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 is a cured product, became cloudy.

As a result of repeated examinations to achieve the above object, the present inventors have interposed urethane bonds at both ends of the molecular chain containing a poly (oxyperfluoroalkylene) group without interposing a poly (oxyalkylene) group. Thus, the perfluoropolyether having an active energy ray polymerizable group is excellent in solubility in a coating solution forming a hard coat layer containing a lactone-modified polyfunctional monomer, and excellent dispersibility in the hard coat layer, It has been found that the curable composition comprising this perfluoropolyether and a lactone-modified polyfunctional monomer has a stretchability and excellent scratch resistance, and can also form a hard coat layer exhibiting a transparent appearance. .

That is, the present invention is a first aspect,

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

(b) a perfluoropolyether having an active energy ray polymerizable group via a urethane bond at both ends of a molecular chain containing a poly (oxyperfluoroalkylene) group (however, the poly (oxyperfluoro) Alkylene) and perfluoropolyether having a poly (oxyalkylene) group between the urethane bond is excluded.) 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 comprising a.

As a 2nd viewpoint, the said (b) perfluoropolyether has the curable composition as described in 1st viewpoint which has at least 2 active energy ray polymerizable groups at each terminal.

As a 3rd viewpoint, the said (b) perfluoropolyether has the curable composition as described in 2nd viewpoint which has at least 3 active energy ray polymerizable groups at each terminal.

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

As a 5th viewpoint, it is related with the curable composition as described in 4th viewpoint which said (b) perfluoropolyether has the partial structure represented by Formula [1].

[Formula 1]

(In the formula, 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.)

As a sixth aspect, the polyfunctional monomer (a) comprises at least one selected from the group consisting of a lactone-modified polyfunctional (meth) acrylate compound and a lactone-modified polyfunctional urethane (meth) acrylate compound. It is related with the curable composition in any one of 1st viewpoint-5th viewpoint.

As a 7th viewpoint, the said (a) polyfunctional monomer is a curable composition in any one of 1st viewpoint-6th viewpoint which is (epsilon) -caprolactone modified polyfunctional monomer.

As an 8th viewpoint, it is related with the curable composition in any one of 1st viewpoint-7th viewpoint containing a (d) solvent further.

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

As a tenth aspect, as a hard coat film comprising a hard coat layer on at least one surface of a film base material, the hard coat layer is composed of a cured film described in the ninth aspect.

As an eleventh aspect, as a hard coat film having a hard coat layer on at least one surface of the film base material, the hard coat layer applies the curable composition according to any one of the first to eighth aspects on the film base material. The present invention relates to a hard coat film formed by a method including a step of forming a coating film and a step of irradiating an active energy ray with the coating film to cure the coating film.

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

As a thirteenth aspect, a perfluoropolyether compound (but not less) having at least three active energy ray polymerizable groups via urethane bonds at both ends of a molecular chain containing a poly (oxyperfluoroalkylene) group. , Perfluoropolyether compound having a poly (oxyalkylene) group between the poly (oxyperfluoroalkylene) group and the urethane bond.).

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

As a 15th viewpoint, it is related with the perfluoropolyether compound described in a 14th viewpoint which has a partial structure represented by Formula [1].

[Formula 2]

(In the formula, 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.)

As a 16th viewpoint, it is related with the surface modifier which consists of the perfluoropolyether compound in any one of 13th to 15th viewpoints.

As a 17th aspect, it is related with the use for the surface modification of the perfluoropolyether compound in any one of 13th to 15th aspects.

According to the present invention, it is possible to provide a curable composition useful for forming a cured film and a hard coat layer having excellent scratch resistance, appearance, and stretchability even in a thin film having a thickness of about 1 to 10 μm.

In addition, according to the present invention, a hard coat film obtained from the curable composition or a hard coat layer formed therefrom can be provided on the surface, excellent scratch resistance and appearance, and also a hard coat having extensibility A film can be provided.

<Curable composition>

The curable composition of the present invention, specifically,

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

(b) a perfluoropolyether having an active energy ray polymerizable group via a urethane bond at both ends of a molecular chain containing a poly (oxyperfluoroalkylene) group (however, the poly (oxyperfluoro) Alkylene) and perfluoropolyether having a poly (oxyalkylene) group between the urethane bond is excluded.) 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 comprising a.

Hereinafter, each component of said (a)-(c) is demonstrated first.

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

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

Preferred (a) active energy ray-curable lactone-modified polyfunctional monomer in the curable composition of the present invention 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.

In addition, in this invention, a (meth) acrylate compound means 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 are modified with lactones such as γ-butyrolactone, δ-valerolactone, and ε-caprolactone (that is, the lactone is a ring-opening part or a ring-opening part). And (meth) acrylate compounds of polyols or polythiols (weighted).

Examples of the polyol include trimethylolpropane, ditrimethylolpropane, pentaerythritol, dipentaerythritol, glycerin, bisphenol A, ethoxylated trimethylolpropane, ethoxylated pentaerythritol, ethoxylated dipentaerythritol, 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 ] decane dimethanol, 1,3-adamantanediol, 1,3-adamantane dimethanol, 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.

Moreover, bis (2-mercaptoethyl) sulfide, bis (4-mercaptophenyl) sulfide, etc. are mentioned as this thiol.

Examples of such a lactone-modified polyfunctional (meth) acrylate compound include lactone-modified trimethylolpropane tri (meth) acrylate, lactone-modified ditrimethylolpropane tetra (meth) acrylate, and lactone-modified pentaerythritol di (meth). ) 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 tree (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 dipentaerythritol 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-octanedioldi (meth) acrylate, lactone-modified 1,9-nonanedioldi (meth) acrylate, lactone-modified 1,10-decanedioldi (meth) Acrylate, lactone-modified tricyclo [5.2.1.0 ^2,6 ] decane dimethanol di (meth) acrylate, lactone-modified 1,3-adamantanediol di (meth) acrylate, lactone-modified 1,3-adaman Tandi methanol 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, lactone modified dioxane glycol di (meth) acrylate, lactone modified bis (2-hydroxyethyl) isocyanurate di (meth) acrylate, lactone modified tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, lactone modified 9,9-bis (4- ( Meth) acryloyloxyphenyl) fluorene, lactone modified 9,9-bis [4- (2- (meth) acryloyloxyethoxy) phenyl] fluorene, lactone modified bis [2- (meth) acrylo Ilthioethyl] sulfide, lactone denaturation [4- (meth) acryloyl thiophenyl] sulfide bus and the like.

Among these, ε-caprolactone is preferable as the modified lactone, and for example, a compound in which the lactone of the above-mentioned 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-capro And lactone-modified dipentaerythritol penta (meth) acrylate, ε-caprolactone-modified dipentaerythritol hexa (meth) acrylate, and the like.

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

For example, the lactone-modified polyfunctional urethane (meth) acrylate is obtained by reacting a polyfunctional isocyanate with a (meth) acrylate having a hydroxyl group modified with lactone, and having a polyfunctional isocyanate and a hydroxy group. What is obtained by the reaction of a (meth) acrylate and a polyol modified with lactone, etc., but the lactone-modified polyfunctional urethane (meth) acrylate compound usable in the present invention is not limited to these examples.

On the other hand, examples of the polyfunctional isocyanate include tolylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, and hexamethylene diisocyanate.

In addition, as the (meth) acrylate having the hydroxy group, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol And penta (meth) acrylate and tripentaerythritol hepta (meth) acrylate.

And the polyol includes, for example, diols such as ethylene glycol, propylene glycol, neopentyl glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, and dipropylene glycol; Polyester polyols which are reaction products of these diols with aliphatic dicarboxylic acids such as succinic acid, maleic acid, and adipic acid or dicarboxylic acid anhydrides; Polyether polyols; And polycarbonate diols.

In the present invention, (a) the active energy ray-curable lactone-modified polyfunctional monomer, one of 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.

[(b) Perfluoropolyether having an active energy ray polymerizable group via a urethane bond at both ends of a molecular chain containing a poly (oxyperfluoroalkylene) group (however, the poly (oxyperfluoro Peralkylene polyether having a poly (oxyalkylene) group between the alkylene) group and the urethane bond.)]

In the present invention, as the component (b), an active energy ray polymerizable group is interposed through a urethane bond at both ends of a molecular chain containing a poly (oxyperfluoroalkylene) group without a poly (oxyalkylene) group. A perfluoropolyether having (hereinafter, simply referred to as "perfluoropolyether having a polymerizable group at both ends" (b)) is used. The 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, the component (b) is excellent in compatibility with the component (a), thereby suppressing the hard coat layer from becoming cloudy, thereby enabling formation of a hard coat layer exhibiting a transparent appearance.

On the other hand, the poly (oxyalkylene) group means a group in which the number of repeat 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 in 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 the divalent fluorocarbon group having 1 to 4 carbon atoms and the oxygen atom are alternately connected, and the oxyperfluoroalkylene group has 2 to 4 carbon atoms. Refers to a group having 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 ]-(oxyperfluor Groups such as lopropane-1,3-diyl group) and-[OCF ₂ C (CF ₃ ) F]-(oxyperfluoropropane-1,2-diyl group).

The oxyperfluoroalkylene group may be used alone or in combination of two or more, in which case, the bonding of the plural types of oxyperfluoroalkylene groups is a block bond or a random bond. It can be either.

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

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

The number of repeating units of the oxyperfluoroalkylene group is preferably 5 to 30, and more preferably 7 to 21, as the total number of repeating units.

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

(Meth) acryloyl group, urethane (meth) acryloyl group, vinyl group, etc. are mentioned as an active energy ray polymerizable group which couple | bonds via the said urethane bond.

(b) The perfluoropolyether having a polymerizable group at both ends is not limited to having one active energy ray polymerizable group such as a (meth) acryloyl group at both ends, and two or more active energy ray polymerizable groups. It may have at both ends, for example, as a terminal structure containing an active energy ray polymerizable group, the structures of A1 to A5 shown below, and acryloyl groups in these structures are substituted with methacryloyl groups. Structure.

[Formula 3]

Examples of the perfluoropolyether having a polymerizable group at both terminals (b) include, for example, a compound represented by the following formula [2].

[Formula 4]

(Wherein, A represents one of the structures represented by the above formulas [A1] to [A5] and structures in which these acryloyl groups are substituted with methacryloyl groups, and PFPE is the poly (oxyperfluor) Loalkylene) group (however, the side directly bonded to L ¹ is an oxy terminal, and the side bonded to an oxygen atom is a perfluoroalkylene 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 monovalent residue excluding OH from m + 1 monohydric alcohol.)

As the alkylene group having 2 to 3 carbon atoms substituted with 1 to 3 fluorine atoms, 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. And CH ₂ CF ₂ is preferred.

Substructure (A-NHC (= O) O) _m L ² -in the compound represented by the formula [2] includes structures represented by the following formulas [B1] to [B12]. have.

[Formula 5]

[Formula 6]

(Wherein, A represents one of the structures represented by the above formulas [A1] to [A5] and the structures in which these acryloyl groups are substituted with methacryloyl groups.)

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

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

As a preferred, perfluoropolyether having a polymerizable group at both ends (b), a compound having a partial structure represented by formula [1] is mentioned.

[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 an integer in the range of 5 to 30 is preferable, and 7 The integer of 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 block or random.

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

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

[Formula 8]

(In the formula, PFPE, L ¹ , L ² and m have the same meaning as described above.) For the hydroxy group present at both ends of the compound represented by, an isocyanate compound having a polymerizable group, that is, the formula Compounds in which isocyanato groups are bonded to the number of bonds in the structures represented by [A1] to [A5] and structures in which the acryloyl groups in these structures are substituted with methacryloyl groups (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.

On the other hand, in the curable composition of the present invention, (b) a perfluoropolyether having an active energy ray polymerizable group via urethane bonds at both ends of a molecular chain containing a poly (oxyperfluoroalkylene) group (however , In addition to the poly (oxyperfluoroalkylene) group and the urethane bond, there is no poly (oxyalkylene) group.), In addition to the poly (oxyperfluoroalkylene) group, a urethane bond to one end of a molecular chain Via a perfluoropolyether having an active energy ray polymerizable group and having a hydroxyl group at the other end (however, between the poly (oxyperfluoroalkylene) group and the urethane bond and the poly (oxyperfluor) Of a molecular chain containing a poly (oxyperfluoroalkylene) group, as shown in the formula [3]) or a poly (oxyalkylene) group between the hydroxy group and the hydroxy group. Both ends Perfluoropolyether having a hydroxy group (but does not have a poly (oxyalkylene) group between the poly (oxyperfluoroalkylene) group and the hydroxy group.) [Has no active energy ray polymerizable group May not contain].

The present invention also has a perfluoropolyether compound having at least three active energy ray polymerizable groups via urethane bonds at both ends of a molecular chain containing a poly (oxyperfluoroalkylene) group. , Perfluoropolyether compound having a poly (oxyalkylene) group between the poly (oxyperfluoroalkylene) group and the urethane bond.)

As said perfluoropolyether compound which has a polymerizable group at both ends, the compound which has the partial structure represented by said formula [1] is preferable.

As described above, the perfluoropolyether compound of the present invention is excellent in compatibility with the component (a), thereby suppressing cloudiness of the hard coat layer, thereby exhibiting a transparent appearance of the hard coat layer. It shows an excellent effect of enabling formation.

The present invention also relates to a surface modifier composed of the perfluoropolyether compound, and the use of the 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 (hereinafter, also simply referred to as "(c) polymerization initiator") that generates a radical by a preferred active energy ray is, for example, an active energy ray such as electron beam, ultraviolet ray, or X-ray. In particular, it is a polymerization initiator that generates radicals by ultraviolet irradiation.

The (c) polymerization initiators include, for example, benzoin, alkylphenones, thioxanthones, azos, azides, diazos, o-quinonediazides, acylphosphine oxides, oxime esters, organic And perium, benzophenones, biscoumarins, bisimidazoles, titanocenes, thiols, halogenated hydrocarbons, trichloromethyltriazines, or onium salts such as iodonium salts and sulfonium salts. These may be used alone or in combination of two or more.

Among these, in the present invention, it is preferable to use alkylphenones as the polymerization initiator (c) from the viewpoints of transparency, surface hardenability, and thin film hardenability. By using alkyl phenones, 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, and 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 ON; 2,2-dimethoxy-1,2-diphenylethan-1-one; And methyl phenyl glyoxylate.

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

[(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).

As the solvent, if the components (a) to (c) are dissolved, and appropriately selected in consideration of the workability at the time of coating required for forming a cured film (hard coat layer) described later, drying properties before and after curing, etc. And, for example, aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, and tetralin; aliphatic or alicyclic hydrocarbons such as n-hexane, n-heptane, mineral spirit, 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, 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; And sulfoxides such as dimethyl sulfoxide, and mixed solvents of two or more of them.

The amount of the solvent (d) used is not particularly limited, but is used, for example, 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, solid content concentration (also referred to as non-volatile content concentration) refers to solid content (solvent in total 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. It shows the content of).

[Other additives]

In addition, to the curable composition of the present invention, as long as the effects of the present invention are not impaired, additives generally added as necessary, for example, polymerization inhibitors, photosensitizers, leveling agents, surfactants, adhesion promoters, Plasticizers, ultraviolet absorbers, antioxidants, storage stabilizers, antistatic agents, inorganic fillers, pigments, dyes and the like may be suitably mixed.

<Cured film>

The curable composition of the present invention can be formed by coating (coating) a substrate to form a coating film, and irradiating the coating with active energy rays to polymerize (curing) it. This cured film is also an object of the present invention. In addition, the hard coat layer in the hard coat film to be described later can be made of this cured film.

As the base material in this case, for example, various resins (polycarbonate, polymethacrylate, polystyrene, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), etc. polyester, polyolefin, polyamide, polyimide) , Epoxy resin, melamine resin, triacetyl cellulose, acrylonitrile-butadiene-styrene copolymer (ABS), acrylonitrile-styrene copolymer (AS), norbornene resin, etc.), metal, wood, paper, glass, slate And the like. The shape of these substrates may be plate-like, film-like, or three-dimensional shaped bodies.

The coating method on the substrate is cast coating, spin coating, blade coating, dip coating, roll coating, spray coating, bar coating, die coating, inkjet printing, printing (convex plate, concave plate) , Flat plate, screen printing, etc.) can be suitably selected, and among them, it can be used in a roll-to-roll method, and also from the viewpoint of thin film coating properties, a convex plate printing method, in particular, a gravure coat It is desirable to use the law. On the other hand, it is preferable to provide the coating after filtering the curable composition using a filter or the like having a pore diameter of about 0.2 μm in advance. On the other hand, when applying, if necessary, a solvent may be added to the curable composition to form a varnish. As the solvent in this case, various solvents mentioned in the above-mentioned [(d) solvent] can be mentioned.

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

After drying, an active energy ray such as ultraviolet rays is irradiated to cure the coating film. Examples of the active energy ray include ultraviolet rays, electron beams, and X rays, and ultraviolet rays are particularly preferred. As a light source used for ultraviolet irradiation, solar light, chemical lamp, low pressure mercury lamp, high pressure mercury lamp, metal halide lamp, xenon lamp, UV-LED, or the like can be used.

After that, the polymerization can also be completed by post-baking, specifically, heating using a hot plate, an oven, or the like.

On the other hand, the thickness of the formed cured film, 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 surface (surface) of a film base material can be produced. This hard coat film is also an object of the present invention, and this hard coat film is suitably used to protect surfaces of various display elements such as, for example, touch panels and liquid crystal displays.

The hard coat layer in the hard coat film of the present invention is a step of forming a coating film by applying the above-mentioned curable composition of the present invention on a film substrate, and this coating film is irradiated with active energy rays such as ultraviolet rays. It can be formed by a method including a step of curing.

As the film base material, among the base materials mentioned in the above-mentioned <cured film>, various transparent resin films usable for optical use are used. Preferably, for example, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polyester, polycarbonate, polymethacrylate, polystyrene, polyolefin, polyamide, polyyi And resin films selected from mid, triacetyl cellulose, and the like.

Moreover, the method mentioned in the above-mentioned <cured film> can be used for the method of apply | coating a curable composition on the said film base material (film forming process) and the method of irradiating an active energy ray to a coating film (curing process). In addition, when a solvent is included (in the varnish form) in the curable composition of the present invention, after the coating film forming process, a process of drying the coating film and removing the solvent may be included as necessary. In that case, the drying method (solvent removal step) of the coating film mentioned in the above-mentioned <cured film> can be used.

The thickness of the hard coat layer thus obtained is preferably 1 to 20 μm, more preferably 1 to 10 μm.

[Example]

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

On the other hand, in Examples, the apparatus and conditions used for preparation of samples and analysis of physical properties are as follows.

(1) Bar coat application

Apparatus: PM-9050MC of SM Co., Ltd.

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

Coating speed: 4m / min

(2) Oven

Apparatus: Dust-free dryer DRC433FA manufactured by Advantech Toyo Co., Ltd.

(3) UV curing

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

Lamp: Heraeus H-bulb, high pressure mercury lamp

(4) Gel permeation chromatography (GPC)

Apparatus: HLC-8220GPC manufactured by Tosoh Corporation

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

Column temperature: 40 ℃

Eluent: Tetrahydrofuran

Detector: RI

(5) Scratch test

Apparatus: Haydon Scientific Co., Ltd. reciprocating wear tester TRIBOGEAR TYPE: 30S

Scanning speed: 3,000mm / min

Scanning distance: 50mm

(6) Total light transmittance, haze

Apparatus: Haze meter NDH5000 manufactured by Nippon Color Industries, Ltd.

(7) Contact angle

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

Measurement temperature: 20 ℃

(8) Tensile test

Apparatus: Tabletop precision universal tester autograph AGS-10kNX manufactured by Shimadzu Corporation

Gripping tool: 1 kN hand-held flat gripping tool

Gripping teeth: High-strength rubber coat gripping teeth

Tensile speed: 20mm / min

Measurement temperature: 20 ℃

In addition, the symbol indicates the following meaning.

PFPE1: Perfluoropolyether having two hydroxy groups without interposing poly (oxyalkylene) groups at both ends [Fomblin (registered trademark) T4 manufactured by SolBase Specialty Polymers]

PFPE2: a perfluoropolyether having a hydroxy group via poly (oxyalkylene) groups (8 to 9 repeating units) at both ends [Fluorolink 5147X manufactured by SolBase Specialty Polymers]

SM2: Perfluoropolyether having two methacryloyl groups via urethane bonds at both ends [Fomblin (registered trademark) MT70, 80% by mass MEK solution manufactured by SolBase Specialty Polymers]

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

DOTDD: Diocetyl dioctyl tin [Neostan (registered trademark) U-830, manufactured by Nitto Chemical Co., Ltd.]

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

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

PETA: pentaerythritol triacrylate / pentaerythritol tetraacrylate mixture [NK ester A-TMM-3LM-N, manufactured by Shin-Nakamura Chemical Industry 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

To 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. The 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 obtained SM1 had a weight average molecular weight: Mw of 3,000 and a dispersion degree: Mw (weight average molecular weight) / Mn (number average molecular weight) of 1.2, as measured by polystyrene by GPC.

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

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

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

To 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. The 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, SM3.

The obtained SM3 had a weight average molecular weight: Mw of 3,100 and a degree of dispersion: Mw / Mn of 1.1 as measured by polystyrene by GPC.

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

Each of the following components was mixed according to the description in Table 1, and a curable composition having a solid content concentration in Table 1 was prepared. In addition, solid content here refers to components other than a solvent. In addition, in the table, [parts] represents [parts by mass].

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

(2) Surface modifier: The amount of the surface modifier shown in Table 1 in Table 1 (solid content conversion)

(3) Polymerization initiator: I2959 5 parts by mass

(4) Solvent: PGME 158 parts by mass

This curable composition was coated with a bar coat on an A4 size double-sided double-adhesive PET film (Lumirror (trademark) U403 manufactured by Toray Industries, 100 μm thick) to obtain a coated film. The coating film was dried in an oven at 120 ° C. for 3 minutes to remove the solvent. A hard coat film having a hard coat layer (cured film) having a film thickness of about 5 μm was produced by exposing the obtained film by exposure to UV light having an exposure amount of 300 mJ / cm ² under a nitrogen atmosphere.

The homogeneity of each curable composition and the obtained hard coat film were evaluated for appearance, scratch resistance, stretchability, total light transmittance, haze, and contact angle of water. The procedure of evaluation of composition homogeneity, appearance, scratch resistance, stretchability, and contact angle is shown below. Table 2 shows the results.

[Composition homogeneity]

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

A: Transparent solution

C: cloudiness

[Exterior]

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

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

C: The entire surface of the hard coat layer is clouded in half, and stains are noticeable.

[Scratch resistance]

The surface of the hard coat layer was loaded with 250 g / cm ² of steel wool attached to a reciprocating abrasion tester (Bonstar (registered trademark) # 0000 (Ultrafine) manufactured by Bonstar Sales Co., Ltd.) to rub 2,000 reciprocations and scratches. It was confirmed visually and evaluated according to the following criteria. On the other hand, when assuming practical use as a hard coat layer, at least B is required, and A is preferable.

A: No scratch

B: Faintly scratched

C: scratches on the front

[Extensibility]

The hard coat film was cut into a rectangle having a length of 80 mm and a width of 10 mm to prepare a test piece. 5 mm, 10%, 15%, 20 elongation rate (= (increased distance between gripping tools) ÷ (distance between gripping tools) x 100) and 5%, 10%, 15%, 20 Tensile test was conducted so as to be%. The maximum elongation at which no crack occurred in the hard coat layer of the test piece was evaluated as elongation.

[Contact angle]

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

[Table 1]

[Table 2]

As shown in Table 1, in the hard coat layer, perfluoropolyether SM1 having four acryloyl groups via urethane bonds at both ends of the lactone-modified acrylate as a polyfunctional monomer and as a surface modifier, ( Example 2) Alternatively, the curable composition using perfluoropolyether SM2 (Example 3) having two methacryloyl groups via urethane bonds at both ends, respectively, represents a transparent solution, and is also curable. 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 using a perfluoropolyether SM3 having two acryloyl groups via a poly (oxyalkylene) group and one urethane bond at each end as a surface modifier, the composition became cloudy and homogeneous. Inferior, and the hard coat layer obtained from this composition had a worse haze than the examples, resulting in a cloudy appearance.

Moreover, the comparative example 1 which used the acrylate which is not lactone-modified as a polyfunctional monomer, the said SM1 as a surface modifier, respectively, became the result which does not have all the extensibility.

As described above, as shown in the results of Examples, a hard coat film that satisfies all of the scratch resistance, stretchability, and appearance is achieved by using a curable composition that combines a lactone-modified polyfunctional monomer and a specific perfluoropolyether. Can be obtained.

Claims (17)

(a) 100 parts by mass of active energy ray-curable lactone-modified polyfunctional monomer,
(b) a perfluoropolyether having an active energy ray polymerizable group via a urethane bond at both ends of a molecular chain containing a poly (oxyperfluoroalkylene) group (however, the poly (oxyperfluoro) Alkylene) and perfluoropolyether having a poly (oxyalkylene) group between the urethane bond is excluded.) 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
Curable composition comprising a. According to claim 1,
The (b) perfluoropolyether has at least two active energy ray polymerizable groups at each end thereof, and a curable composition. According to claim 2,
The (b) perfluoropolyether has at least three active energy ray polymerizable groups at each end thereof, and a curable composition. The method according to any one of claims 1 to 3,
The poly (oxyperfluoroalkylene) group is a group having-[OCF ₂ ]-and-[OCF ₂ CF ₂ ]-as repeating units, the curable composition. According to claim 4,
The (b) perfluoropolyether has a partial structure represented by formula [1], curable composition.
[Formula 1]

(In the formula, 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.) The method according to any one of claims 1 to 5,
The (a) polyfunctional monomer is a lactone-modified polyfunctional (meth) acrylate compound and at least one selected from the group consisting of a lactone-modified polyfunctional urethane (meth) acrylate compound, curable composition. The method according to any one of claims 1 to 6,
The said (a) polyfunctional monomer is an epsilon-caprolactone modified polyfunctional monomer, curable composition. The method according to any one of claims 1 to 7,
A curable composition further comprising (d) a solvent. The cured film obtained from the curable composition in any one of Claims 1-8. 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 of claim 9. A hard coat film having a hard coat layer on at least one side of a film base material, wherein the hard coat layer forms a coating film by applying the curable composition according to any one of claims 1 to 8 on a film base material. A hard coat film formed by a method including a process to be cured by irradiating an active energy ray to the coating film and curing. The method of claim 10 or 11,
The hard coat film, wherein the hard coat layer has a film thickness of 1 to 10 μm. Perfluoropolyether compounds having at least three active energy ray polymerizable groups via urethane bonds at both ends of the molecular chain containing a poly (oxyperfluoroalkylene) group (however, the poly (oxy Perfluoroalkylene) groups and perfluoropolyether compounds having a poly (oxyalkylene) group between the urethane bonds are excluded.). The method of claim 13,
A perfluoropolyether compound, wherein the poly (oxyperfluoroalkylene) group is a group having-[OCF ₂ ]-and-[OCF ₂ CF ₂ ]-as repeating units. The method of claim 14,
A perfluoropolyether compound having a partial structure represented by formula [1].
[Formula 2]

(In the formula, 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.) A surface modifier comprising the perfluoropolyether compound according to any one of claims 13 to 15. Use of the perfluoropolyether compound according to any one of claims 13 to 15 for surface modification.