JP2022047947A - Curable composition for forming hard coat layer containing specific urethane (meth)acrylate - Google Patents

Abstract

To provide a curable composition capable of forming a hard coat layer which achieves both high scratch resistance and stretchability and can be imparted with antistatic properties.SOLUTION: The curable composition contains: (a) 100 pts.mass of at least one urethane (meth)acrylate having any one of a partial structure of an allophanate-modified product of a diisocyanate, a partial structure of a biuret-modified product of the diisocyanate, and a partial structure of an isocyanurate-modified product of the diisocyanate; (b) 0.05 to 10 pts.mass of a perfluoropolyether having an active energy ray-polymerizable group at a terminal of a molecular chain containing a poly(oxyperfluoroalkylene) group; and (c) 1 to 20 pts.mass of a polymerization initiator which generates radicals by means of active energy rays.SELECTED DRAWING: None

Description

INDUSTRIAL APPLICABILITY The present invention relates to a curable composition useful as a material for forming a hard coat layer applied to the surface of various display elements such as flexible displays, and is excellent in scratch resistance and stretchability, and can also impart antistatic properties. The present invention relates to a curable composition capable of forming a hard coat layer.

Smartphones are now the most common form of mobile phone and have become an integral part of our daily lives. A cover glass is used on the surface of the smartphone to prevent the display from being scratched. In recent years, as the above-mentioned display, a bendable display, a so-called flexible display, has been developed. Flexible displays are expected to have a wide range of uses as displays that can be deformed such as bending and winding. However, glass is generally hard and difficult to bend back, so it cannot be applied to flexible displays. Therefore, instead of glass, it is attempted to apply a plastic film provided with a scratch-resistant hard coat layer for scratch prevention to the surface of a flexible display. When a flexible display to which a plastic film provided with this hardcoat layer is applied to the surface is curved with the display side facing outward (that is, the hardcoat layer facing outward), the outermost hardcoat layer has a tensile direction. Therefore, the hardcourt layer is required to have a certain stretchability.

In general, as a method for imparting scratch resistance to the hard coat layer, for example, a high-density crosslinked structure is formed, that is, a crosslinked structure having low molecular motion is formed to increase the surface hardness and resist external force. Is adopted. As a material for forming these hardcourt layers, a polyfunctional acrylate-based material that is three-dimensionally crosslinked by radicals is currently most used. However, polyfunctional acrylate-based materials are usually inferior in stretchability due to their high crosslink density. As described above, there is a trade-off relationship between the stretchability of the hard coat layer and the scratch resistance, and it is an issue to balance the characteristics of both.

As one of the methods for improving scratch resistance, a method of mixing a silicone or a fluorine-based surface modifier with a curable composition forming a hardcoat layer to impart slipperiness to the surface of the cured film has been known so far. ing. Further, by using an aliphatic urethane (meth) acrylate having an alicyclic skeleton and a photopolymerizable unsaturated group in combination with a fluorine-containing compound having a photopolymerizable unsaturated group, a certain level of scratch resistance is exhibited. It has been reported (Patent Document 1).

On the other hand, when a hard coat film is used as a front protective material for a display, it may be required to provide antistatic properties in order to suppress adhesion of dust and the like due to static electricity generated during laminating and to prevent malfunction of the display. As a countermeasure against such static electricity, it is desirable that the surface resistance value is about 10 ¹⁰ Ω / □.

Japanese Unexamined Patent Publication No. 2016-125049

The hard coat layer described in Patent Document 1 has a certain level of scratch resistance, but is not at a satisfactory level. An object of the present invention is to provide a curable composition capable of forming a hard coat layer capable of achieving both high scratch resistance and stretchability and further imparting antistatic properties.

（上記式中、Ｒ^１、Ｒ^２及びＲ^３はそれぞれ炭素原子数４乃至１５の２価の炭化水素基を表し、Ｒ^０は１価アルコールの残基を表す。） A first aspect of the present invention is (a) 100 parts by mass of at least one type of urethane (meth) acrylate having any one of the partial structures represented by the following formulas [1] to [3]. b) At the end of the molecular chain containing a poly (oxyperfluoroalkylene) group, a radical is generated by 0.05 parts by mass to 10 parts by mass of a perfluoropolyether having an active energy ray-polymerizable group, and (c) an active energy ray. It is a curable composition containing 1 part by mass to 20 parts by mass of a polymerization initiator generated.

(In the above formula, R ¹ , R ² and R ³ each represent a divalent hydrocarbon group having 4 to 15 carbon atoms, and R ⁰ represents a residue of a monohydric alcohol.)

（上記式中、Ｒ^０及びＲ^１は前記式［１］の定義と同義であり、Ｒ^２は前記式［２］の定義と同義であり、Ｒ^３は前記式［３］の定義と同義である。） The (a) urethane (meth) acrylate is composed of, for example, a (meth) acrylate compound having at least one (a1) hydroxy group and (a2) a compound represented by the following formulas [1'] to [3']. A reaction product with at least one isocyanate compound selected from the group.

(In the above formula, R ⁰ and R ¹ are synonymous with the definition of the above formula [1], R ² is synonymous with the definition of the above formula [2], and R ³ is synonymous with the definition of the above formula [3]. Is.)

The isocyanate compound (a2) is, for example, a compound represented by the formula [1'].

The (b) perfluoropolyether has an active energy ray-polymerizable group at the end of the molecular chain containing the poly (oxyperfluoroalkylene) group, for example, via a urethane bond.

The (b) perfluoropolyether has at least two active energy ray-polymerizable groups at the end of the molecular chain containing the poly (oxyperfluoroalkylene) group, for example, via a urethane bond.

The (b) perfluoropolyether has at least two active energy ray-polymerizable groups at both ends of the molecular chain containing the poly (oxyperfluoroalkylene) group, for example, via a urethane bond.

The poly (oxyperfluoroalkylene) group of the (b) perfluoropolyether has both a repeating unit- [CF ₂ O]-and a repeating unit- [CF ₂ CF ₂ O] -, and these repeating units are used. It is a group consisting of a block bond, a random bond, or a block bond and a random bond.

（上記式［４］中、ｎは、繰り返し単位－［ＣＦ_２ＣＦ_２Ｏ］－の数と、繰り返し単位－［ＣＦ_２Ｏ］－の数との総数であって５乃至３０の整数を表し、前記繰り返し単位－［ＣＦ_２ＣＦ_２Ｏ］－と、前記繰り返し単位－［ＣＦ_２Ｏ］－は、ブロック結合、ランダム結合、又は、ブロック結合及びランダム結合にて結合してなる。） The molecular chain containing the poly (oxyperfluoroalkylene) group has, for example, a structure represented by the following formula [4].

(In the above equation [4], n is the total number of the number of repeating units- [CF ₂ CF ₂ O] -and the number of repeating units- [CF ₂ O] -representing an integer of 5 to 30. , The repeating unit- [CF ₂ CF ₂ O]-and the repeating unit- [CF ₂ O] -are bound by a block bond, a random bond, or a block bond and a random bond.)

The curable composition of the present invention may further contain (d) 10 parts by mass to 55 parts by mass of the antistatic agent. The (d) antistatic agent contains, for example, metal oxide particles. The metal oxide particles contain oxides of at least one element selected from the group consisting of, for example, tin, zinc, and indium. The metal oxide particles contain, for example, tin oxide to which a dopant may be added. The metal oxide particles contain, for example, phosphorus-doped tin oxide and at least one of tin oxide whose surface is coated with antimony pentoxide.

The curable composition of the present invention may further contain (e) a solvent.

The second aspect of the present invention is a cured film obtained from the curable composition of the present invention.

A third aspect of the present invention is a hard-coated film having a hard-coated layer on at least one surface of a film substrate, wherein the hard-coated layer is made of a cured film obtained from the curable composition of the present invention. It is a coat film.

The hard coat layer is formed by a method including, for example, a step of applying the curable composition of the present invention on a film substrate to form a coating film, and a step of irradiating the coating film with active energy rays to cure the coating film. Being done.

The hard coat layer is, for example, active in a step of applying the curable composition of the present invention on a film substrate to form a coating film, a step of removing the solvent from the coating film by heating, and a step of removing the solvent from the coating film. It is formed by a method including a step of irradiating with energy rays and curing.

The hardcourt layer has a film thickness of, for example, 1 μm to 10 μm.

A fourth aspect of the present invention includes a step of applying the curable composition of the present invention onto a film substrate to form a coating film, and a step of irradiating the coating film with active energy rays to cure the laminate. It is a manufacturing method of.

According to the present invention, it is possible to provide a curable composition useful for forming a cured film and a hard coat layer that have both excellent scratch resistance and high stretchability even in a thin film having a thickness of 1 μm to 10 μm. .. Further, according to the present invention, it is possible to provide a hard coat film provided with a cured film obtained from the curable composition or a hard coat layer made of the cured film, and there is a trade-off relationship between scratch resistance and stretching. It is possible to provide a hard-coated film having excellent properties. Further, according to the present invention, a curable composition useful for forming a cured film and a hardcoat layer having antistatic properties in addition to the scratch resistance and stretchability described above, and a hardcoat excellent in these three performances. A hardcourt film with layers can be provided.

<Curable composition>
Each component of the curable composition of the present invention will be described below.
[(A) Urethane (meth) acrylate]
In the curable composition of the present invention, (a) urethane (meth) acrylate is a compound having any one of the partial structures represented by the formulas [1] to [3], and is, for example, (a). a1) A (meth) acrylate compound having at least one hydroxy group and (a2) at least one isocyanate compound selected from the group consisting of the compounds represented by the above formulas [1'] to [3']. It is a reaction product obtained by reacting by a known method. Above all, as (a) urethane (meth) acrylate, it is most preferable to have a partial structure represented by the above formula [1].

Examples of the (meth) acrylate compound having at least one (a1) hydroxy group include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, and 2-hydroxybutyl acrylate. 2-Hydroxybutyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, 2- (2-hydroxyethoxy) ethyl acrylate, 2- (2-hydroxyethoxy) ethyl methacrylate, glycerin diacrylate, glycerin dimethacrylate, pentaerythritol Examples thereof include triacrylate, pentaerythritol trimethacrylate, dipentaerythritol pentaacrylate, and dipentaerythritol pentamethacrylate.

In the formulas [1'] to [3'], R ¹ , R ² and R ³ are groups obtained by removing two isocyanate groups from the diisocyanate compound, and are, for example, a tetramethylene group, a pentamethylene group and a hexamethylene group. , Trilen group, xylylene group, phenylene group, naphthylene group, dicyclohexylmethane group, trimethylhexamethylene group, isocyanate group, and diphenylmethane group. In the above formula [1'], ^R0 is a group obtained by removing the OH group from the monohydric alcohol that reacts with the diisocyanate compound to form a urethane bond.

The (a) urethane (meth) acrylate of the curable composition of the present invention can be used alone or in combination of two or more.

[(B) Perfluoropolyether]
The preferred (b) perfluoropolyether in the curable composition of the present invention has an active energy ray-polymerizable group at the end of the molecular chain containing a poly (oxyperfluoroalkylene) group via a urethane bond. The end of the molecular chain of the perfluoropolyether may be any end or a part of the end of the molecular chain. When the molecular chain of the perfluoropolyether is linear, all ends and some ends of the molecular chain are both ends and one end of the linear molecular chain, respectively. Examples of the linking group between the poly (oxyperfluoroalkylene) group and the urethane bond include a hydrocarbon group having an ether bond, and the hydrocarbon group has at least one hydrogen atom of a fluorine atom. It may be replaced. In the curable composition of the present invention, (b) perfluoropolyether serves as a surface modifier in the hardcoat layer formed from the curable composition of the present invention. Further, since (b) perfluoropolyether has excellent compatibility with (a) urethane (meth) acrylate, cloudiness is suppressed and a hard coat layer having a transparent appearance can be formed.

As the poly (oxyperfluoroalkylene) group,-[CF ₂ O]-(oxyperfluoromethylene group) and- [CF ₂ CF ₂ O]-from the viewpoint of obtaining a cured film having good scratch resistance. A group having both (oxyperfluoroethylene group) as a repeating unit is preferable. In that case, the bond of these oxyperfluoroalkylene groups may be either a block bond or a random bond. The total number of repeating units of the oxyperfluoroalkylene group is preferably in the range of 5 to 30, and more preferably in the range of 7 to 21.

式［４］中のｎは、繰り返し単位－［ＣＦ_２ＣＦ_２Ｏ］－の数と、繰り返し単位－［ＣＦ_２Ｏ］－の数との総数を表し、５乃至３０の範囲の整数が好ましく、７乃至２１の範囲の整数がより好ましい。また、繰り返し単位－［ＣＦ_２ＣＦ_２Ｏ］－の数と、繰り返し単位－［ＣＦ_２Ｏ］－の数との比率は、２：１乃至１：２の範囲であることが好ましく、およそ１：１の範囲とすることがより好ましい。これら繰り返し単位の結合は、ブロック結合及びランダム結合の何れであってもよい。 The molecular chain containing the poly (oxyperfluoroalkylene) group preferably has a structure represented by the following formula [4].

N in the formula [4] represents the total number of the number of repeating units- [CF ₂ CF ₂ O] -and the number of repeating units- [CF ₂ O]-, and an integer in the range of 5 to 30 is preferable. , 7 to 21 are more preferred. The ratio of the number of repeating units- [CF ₂ CF ₂ O]-to the number of repeating units- [CF ₂ O]-is preferably in the range of 2: 1 to 1: 2, and is approximately 1. It is more preferable to set it in the range of 1. The binding of these repeating units may be either a block binding or a random binding.

Examples of the active energy ray-polymerizable group include (meth) acryloyl group and vinyl group. (B) The perfluoropolyether is not limited to one having one active energy ray-polymerizable group at the end of the molecular chain containing a poly (oxyperfluoroalkylene) group, and is not limited to those having two or more active energy ray-polymerizable groups. It may have. Examples of the terminal structure containing the active energy ray-polymerizable group include structures of the formulas [A1] to [A5] shown below, and structures in which the acryloyl group in these structures is replaced with a methacryloyl group. Among these structures, the structures of the formulas [A3], [A4] and [A5] having two or more active energy ray-polymerizable groups, and the structures in which the acryloyl group in these structures is replaced with a methacryloyl group. Is preferable.

In the curable composition of the present invention, the content of (b) perfluoropolyether is 0.05 parts by mass to 10 parts by mass, preferably 0 parts by mass with respect to 100 parts by mass of the (a) urethane (meth) acrylate. It is 05 parts by mass to 5 parts by mass. When the content of (b) perfluoropolyether is 0.05 parts by mass or more, sufficient scratch resistance can be imparted to the hardcoat layer, and (c) the content of perfluoropolyether is high. When the amount is 10 parts by mass or less, it is possible to obtain a hard coat layer that is sufficiently compatible with (a) urethane (meth) acrylate and has less cloudiness.

In addition, (b) perfluoropolyether can be used individually by 1 type or in combination of 2 or more types. When two or more types are combined, one end (one end) of the molecular chain containing a poly (oxyperfluoroalkylene) group has an active energy ray-polymerizable group via a urethane bond, and the other of the molecular chain. Perfluoropolyether having a hydroxy group at one end (the other end) may be contained. Further, (b) the perfluoropolyether is a poly (oxyalkylene) between the poly (oxyperfluoroalkylene) group and the urethane bond, and between the poly (oxyperfluoroalkylene) group and the hydroxy group. The condition that it does not have a group can be added.

[(C) Polymerization Initiator]
The preferred (c) polymerization initiator in the curable composition of the present invention is, for example, a polymerization initiator that generates radicals by active energy rays such as electron beams, ultraviolet rays, and X-rays, particularly by irradiation with ultraviolet rays.

(C) Examples of the polymerization initiator include benzoins, alkylphenones, thioxanthones, azos, azides, diazos, o-quinonediazides, acylphosphine oxides, oxime esters, organic peroxides and benzophenones. , Biscmarins, bisimidazoles, titanoses, thiols, halogenated hydrocarbons, trichloromethyltriazines, and onium salts such as iodonium salts and sulfonium salts. These polymerization initiators may be used alone or in combination of two or more. In the present invention, from the viewpoint of transparency, surface curability and thin film curability, it is preferable to use (c) alkylphenones as the polymerization initiator. By using alkylphenones, a cured film with further improved scratch resistance can be obtained.

Examples of the alkylphenones include 1-hydroxycyclohexylphenylketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, and 2-hydroxy-1- (4- (2-hydroxyethoxy) phenyl)-. Α-Hydroxyalkyl such as 2-methylpropane-1-one, 2-hydroxy-1- (4- (4- (2-hydroxy-2-methylpropionyl) benzyl) phenyl) -2-methylpropane-1-one Phenyls; 2-methyl-1- (4- (methylthio) phenyl) -2-morpholinopropane-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butane-1-one, etc. Α-Aminoalkylphenones; 2,2-dimethoxy-1,2-diphenylethane-1-one; and methylphenylglycoxylate.

In the curable composition of the present invention, the content of (c) the polymerization initiator is 1 part by mass to 20 parts by mass, preferably 2 parts by mass to 10 parts by mass with respect to 100 parts by mass of the (a) urethane (meth) acrylate. It is a mass part.

[(D) Antistatic agent]
The curable composition of the present invention may contain (d) an antistatic agent as an optional component. (D) Examples of the antistatic agent include an antistatic agent containing metal oxide particles. As the metal oxide particles, fine particles having a primary particle diameter of 4 nm to 100 nm can be adopted. By setting the primary particle diameter of the metal oxide particles within the above numerical range, antistatic properties can be imparted without affecting scratch resistance and stretchability, and a cured film leading to the realization of transparency. Can be obtained. In the present invention, the primary particle size of the metal oxide particles refers to the particle size of the individual particles observed using a transmission electron microscope.

The metal oxide particles can include, for example, an oxide of at least one element selected from the group consisting of tin, zinc, and indium. Specifically, tin oxide (SnO ₂ ), tin-doped indium oxide (ITO), fluorine-doped tin oxide (FTO), antimony-doped tin oxide (ATO), phosphorus-doped tin oxide (PTO), gallium-doped zinc oxide (GZO), and aluminum. Doped zinc oxide (AlZO), antimony-doped zinc oxide (AZO), indium-doped zinc oxide or zinc oxide-doped indium oxide (IZO), and indium gallium oxide zinc oxide (IGZO) can be mentioned, among which dopants are added. Oxides of the above elements are preferable as antistatic agents, and phosphorus-doped tin oxide (PTO) is particularly preferable.

Examples of the metal oxide particles include surface-coated metal oxide particles having a metal oxide as a nucleus and whose surface is coated with an acidic or basic oxide. As the nucleus, for example, in addition to the above metal oxide particles such as tin oxide, titanium oxide, titanium oxide-tin oxide complex, zirconium oxide-tin oxide complex, tungsten oxide-tin oxide complex, and titanium oxide-oxidation. A zirconium-tin oxide complex can be mentioned. Examples of the acidic or basic oxide include antimony pentoxide, silicon oxide-antimony pentoxide complex, and silicon oxide-tin oxide complex.

In the present invention, when (d) an antistatic agent is contained, the content thereof is 10 parts by mass to 55 parts by mass with respect to 100 parts by mass of the (a) urethane (meth) acrylate. The (d) antistatic agent may be used alone or in combination of two or more.

[(E) Solvent]
The curable composition of the present invention may contain (e) a solvent as an optional component, that is, it may be in the form of a varnish. As the solvent (e), the dissolution / dispersibility of the components (a) to (c) and the optional component (d), and the curing related to the formation of the cured film (hard coat layer) described later. The sexual composition may be appropriately selected in consideration of workability at the time of coating, drying property before and after curing, and the like.

As the solvent (e), aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene and tetraline; aliphatic or alicyclic hydrocarbons such as n-hexane, n-heptane, mineral spirit and cyclohexane; Halogens such as methyl chloride, methyl bromide, methyl iodide, dichloromethane, chloroform, carbon tetrachloride, trichloroethylene, perchloroethylene, o-dichlorobenzene; ethyl acetate, propyl acetate, butyl acetate, methoxybutyl acetate, methyl cellosolve Esters or ester ethers such as acetate, ethyl cellosolve acetate, propylene glycol monomethyl ether acetate (PGMEA); diethyl ether, tetrahydrofuran (THF), 1,4-dioxane, methyl cellosolve, ethyl cellosolve, butyl cellosolve, propylene glycol monomethyl ether, Ethers such as propylene glycol monoethyl ether (PGME), propylene glycol mono-n-propyl ether, propylene glycol monoisopropyl ether, propylene glycol mono-n-butyl ether; acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), Ketones such as 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; Amidos such as N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP); and sulfoxides such as dimethylsulfoxide (DMSO), and their solvents. Examples thereof include a solvent in which two or more of them are mixed.

The content of the solvent (e) in the curable composition of the present invention is not particularly limited, but for example, the solid content concentration of the curable composition of the present invention is 1% by mass to 70% by mass, preferably 5% by mass to 50%. It is a concentration that becomes mass%. Here, the solid content concentration (also referred to as non-volatile content concentration) is the total of the components (a) to (c) of the curable composition of the present invention, and the components (d) and other additives which are optional components. Represents the content of solid content (all components minus solvent components) with respect to mass (total mass).

<Hardened film>
The curable composition of the present invention can form a cured film by applying (coating) it on a substrate to form a coating film and irradiating the coating film with active energy rays to polymerize (cure) the coating film. The cured film is also the subject of the present invention. Further, as the hard coat layer in the hard coat film described later, one made of the above-mentioned cured film can be used.

As the base material, for example, polyesters such as various resins (polycarbonate, polymethacrylate, polystyrene, polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyurethane, thermoplastic polyurethane (TPU), polyolefin, polyamide, polyimide, epoxy resin , Melamine resin, triacetyl cellulose (TAC), acrylonitrile-butadiene-styrene copolymer (ABS), acrylonitrile-styrene copolymer (AS), norbornene resin), metal, wood, paper, glass, slate. Can be done. The shape of these base materials may be a plate shape, a film shape, or a three-dimensional molded body.

The coating method on the substrate is cast coating method, spin coating method, blade coating method, dip coating method, roll coating method, spray coating method, bar coating method, die coating method, inkjet method, printing method (toppan printing method). , Intaglio printing method, flat plate printing method, screen printing method, etc.), etc., can be used for the roll-to-roll method, and from the viewpoint of thin film coatability, the letterpress printing method can be used. In particular, it is desirable to use the gravure coat method. It is preferable that the curable composition of the present invention is filtered in advance using a filter having a pore size of about 0.2 μm and then applied for coating. At the time of application, a solvent may be further added to the curable composition, if necessary. As the solvent in this case, various solvents mentioned in the above-mentioned [(e) solvent] can be mentioned.

After the curable composition of the present invention is applied onto the substrate to form a coating film, the coating film is pre-dried by a heating means such as a hot plate or an oven as necessary to remove the solvent (solvent removal step). .. The conditions for heating and drying at this time are preferably, for example, 40 ° C. to 120 ° C. for about 30 seconds to 10 minutes. After drying, the coating film is cured by irradiating it with active energy rays such as ultraviolet rays. Examples of the active energy ray include ultraviolet rays, electron beams and X-rays, and ultraviolet rays are particularly preferable. As the light source used for ultraviolet irradiation, for example, a sunbeam, a chemical lamp, a low pressure mercury lamp, a high pressure mercury lamp, a metal halide lamp, a xenon lamp, and a UV-LED can be used. Further, after that, the polymerization may be completed by performing post-baking, specifically by heating using a heating means such as a hot plate or an oven.

The thickness of the cured film formed is usually 0.1 μm to 50 μm, preferably 0.5 μm to 20 μm after drying and curing.

<Hardcourt film>
The curable composition of the present invention can be used to produce a hardcourt film having a hardcourt layer on at least one surface (surface) of the film substrate. The hard-coated film is also an object of the present invention, and the hard-coated film is suitably used for protecting the surface of various display elements such as a touch panel and a liquid crystal display.

The hard coat layer in the hard coat film of the present invention includes a step of applying the curable composition of the present invention on a film substrate to form a coating film, and a step of removing a solvent by heating if necessary, and the coating. The film can be formed by a method including a step of irradiating the film with active energy rays such as ultraviolet rays and curing the coating film. A method for producing a hard-coated film including a hard-coated layer on at least one surface of a film substrate including these steps is also an object of the present invention.

As the film base material, among the base materials mentioned in the above-mentioned <cured film>, various transparent resin films that can be used for optical applications are used. Preferred resin films include, for example, polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene naphthalate (PEN), polyurethanes, thermoplastic polyurethanes (TPUs), polycarbonates, polymethacrylates, polystyrenes, and polyolefins. Examples thereof include films such as polyamide, polyimide, and triacetyl cellulose (TAC).

The method for applying the curable composition of the present invention onto the film substrate (coating film forming step) and the method for irradiating the coating film with active energy rays (curing step) are described in the above-mentioned <cured film>. Method can be used. When the curable composition of the present invention contains a solvent (in the form of a varnish), a step of drying the coating film to remove the solvent can be included after the coating film forming step, if necessary. In that case, the coating film drying method (solvent removing step) described in the above-mentioned <cured film> can be used.

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

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples. In the examples, the equipment and conditions used for sample preparation and analysis of physical properties are as follows.

(1) Coating device by bar coater: PM-9050MC manufactured by SMT Co., Ltd.
Bar: A-Bar OSP-22 manufactured by OSG System Products Co., Ltd., maximum wet film thickness 22 μm (equivalent to wire bar # 9)
Coating speed: 4 m / min (2) Oven device: Sanki Instrumentation Co., Ltd. 2-layer clean oven (upper and lower type) PO-250-45-D
(3) UV curing device: CV-110QC-G manufactured by Heraeus Co., Ltd.
Lamp: Electrodeless lamp H-bulb manufactured by Heraeus Co., Ltd.
(4) Gel Permeation Chromatography (GPC)
Equipment: HLC-8220GPC manufactured by Tosoh Corporation
Column: Showa Denko Corporation Shodex® GPC K-804L, GPC K-805L
Column temperature: 40 ° C
Eluent: Tetrahydrofuran Detector: RI
(5) Scratch test equipment: Reciprocating wear tester manufactured by Shinto Kagaku Co., Ltd. TRIBOGEAR TYPE: 30S
Scanning speed: 5,000 mm / min Scanning distance: 50 mm
(6) Tensile test equipment: Shimadzu Corporation desktop precision universal testing machine Autograph AGS-10kNX
Grip: 1kN Manual screw type flat grip Grip: High-strength rubber-coated grip Tooth Tensile speed: 10 mm / min Measurement temperature: 23 ° C
(7) Surface resistance measuring device: High resistivity meter Hiresta UP MCP-HT450 manufactured by Mitsubishi Chemical Corporation
Probe: URS probe Registration table: UFL
Applied voltage: 10V

The abbreviations have the following meanings.
Polyfunctional acrylate having one hydroxy group (a1-1):
Dipentaerythritol pentaacrylate / hexaacrylate mixture [Aronix (registered trademark) M-403 manufactured by Toagosei Co., Ltd., penta body ratio 50% to 60% (catalog value), estimated hydroxyl value = 63.3 mgKOH / g (penta body) Calculated as 55% and 45% hexagon)]
Allophanate polyisocyanate (a2-1):
Hexamethylene diisocyanate allophanate modified product [Duranate (registered trademark) A201H manufactured by Asahi Kasei Chemicals Co., Ltd., isocyanate group content = 17.2% by mass, bifunctional]
Biuret polyisocyanate (a2-2):
Biuret modified product of hexamethylene diisocyanate [Duranate (registered trademark) 24A-100 manufactured by Asahi Kasei Chemicals Co., Ltd., isocyanate group content = 23.5% by mass, trifunctional]
Isocyanurate-form polyisocyanate (a2-3):
Isocyanurate modified product of hexamethylene diisocyanate [Duranate (registered trademark) TLA-100 manufactured by Asahi Kasei Chemicals Co., Ltd., isocyanate group content = 23.3% by mass, trifunctional]
Adduct body polyisocyanate (a2-4):
Adduct modified product of hexamethylene diisocyanate [Duranate (registered trademark) P301-75E manufactured by Asahi Kasei Chemicals Co., Ltd., isocyanate group content = 12.5% by mass, bifunctional]
PFPE: Perfluoropolyether having two hydroxy groups at both ends without a poly (oxyalkylene) group [Fombin (registered trademark) T4 manufactured by Solvay Specialty Polymers Co., Ltd.]
BEI: 1,1-bis (acryloyloxymethyl) ethyl isocyanate [Showa Denko KK Karens (registered trademark) BEI]
DOTDD: Dioctyl tin dineodecanoate [Neostan (registered trademark) U-830 manufactured by Nitto Kasei Co., Ltd.]
SM2: Perfluoropolyether urethane acrylate having a total of four acryloyl groups at both ends [FLUOROLINK (registered trademark) AD-1700 manufactured by Solvay Specialty Polymers, non-volatile content 70% by mass solution]
SM3: Polydimethylsiloxane having a methacryloyl group at one end [Silaplane (registered trademark) FM-0721 manufactured by JNC Co., Ltd.]
O2959: 2-Hydroxy-1- (4- (2-hydroxyethoxy) phenyl) -2-methylpropan-1-one [OMNIRAD® 2959 manufactured by IGM Resins]
MEK: Methyl ethyl ketone MeOH: Methanol antistatic agent d-1:
Lin-doped tin oxide 20% by mass isopropyl alcohol dispersion sol [Celnax (registered trademark) CX-S204IP manufactured by Nissan Chemical Co., Ltd., primary particle size: 5 nm to 20 nm, secondary particle size: 10 nm to 20 nm]
* Here, the primary particle diameter and the secondary particle diameter refer to the average particle diameter measured by observation with a transmission electron microscope. The particle size is determined by dropping a sol from a transmission electron microscope onto a copper mesh, drying it, and observing it with a transmission electron microscope (JEM-1020 manufactured by JEOL Ltd.) at an acceleration voltage of 100 kV. The measured and averaged value was obtained as the average primary particle size.
Antistatic agent d-2:
30% by mass methanol-dispersed sol of core-shell particles with a primary particle diameter of 30 nm to 40 nm whose surface is coated with tin oxide as a nucleus [Celnax (registered trademark) HX-307M1 manufactured by Nissan Chemical Industries, Ltd.]

[Production Example 1] Production of surface modifier SM1 In a screw tube, 1.19 g (0.5 mmol) of PFPE, 0.52 g (2.0 mmol) of BEI, and 0.017 g of DOTDD (total mass of PFPE and BEI are 0. 01 times the amount) and 1.67 g of MEK were charged. This mixture was stirred at room temperature (approximately 23 ° C.) for 72 hours using a stirrer chip to obtain a 50% by mass MEK solution of the surface modifier as the target compound. The weight average molecular weight: Mw measured by GPC of the obtained SM1 in terms of polystyrene was 3,000, and the dispersity: Mw (weight average molecular weight) / Mn (number average molecular weight) was 1.2.

[How to determine the amount of isocyanate charged during urethane acrylate production]
When a polyfunctional acrylate (a1-1) having one hydroxy group is reacted with various polyisocyanates (a2-1) to (a2-4) to produce a urethane acrylate, the amount of the polyisocyanate charged is [. Calculated using (a1-1) hydroxyl value / 561) × (42 × 100 / isocyanate group content) × [(a1-1) amount / 100] × (number of NCO groups / number of OH groups) ..

[Production Example 2] 10 g of (a1-1) and 2.76 g of allophanate polyisocyanate (a2-1) are charged in a screw tube for producing urethane acrylate UA1 so that the number of OH groups / the number of NCO groups = 1. Further, 0.13 g of DOTDD [0.01 times the total mass of (a1-1) and (a2-1)], and 3.22 g of MEK were charged. The obtained mixture was stirred using a stirrer chip at room temperature (approximately 23 ° C.) until the infrared absorption spectrum of 2260 cm ^-1 showing an isocyanate group disappeared, and then an 80 mass% MEK solution of urethane acrylate UA1 as the target compound. Got

[Production Example 3] 10 g of (a1-1) and 3.02 g of biuret-type polyisocyanate (a2-2) so that the number of OH groups / the number of NCO groups = 2/3 in the screw tube for producing urethane acrylate UA2. Was charged, and 0.13 g of DOTDD [0.01 times the total mass of (a1-1) and (a2-2)] and 2.96 g of MEK were charged. The obtained mixture is stirred at room temperature (about 23 ° C.) for about 3 hours using a stirrer chip, then 0.33 g of MeOH is charged to eliminate residual isocyanate groups, and the isocyanate groups are shown at room temperature (about 23 ° C.). After stirring until the infrared absorption spectrum of 2260 cm ^-1 disappeared, an 80 mass% MEK / MeOH solution of urethane acrylate UA2 as the target compound was obtained.

[Production Example 4] Production of urethane acrylate UA3 In a screw tube, 10 g (a1-1) so that the number of OH groups / the number of NCO groups = 2/3, and isocyanurate-form polyisocyanate (a2-3) 3. 05 g was charged, and 0.13 g of DOTDD [0.01 times the total mass of (a1-1) and (a2-3)] and 2.97 g of MEK were charged. The obtained mixture is stirred at room temperature (about 23 ° C.) for about 3 hours using a stirrer chip, then 0.33 g of MeOH is charged to eliminate residual isocyanate groups, and the isocyanate groups are shown at room temperature (about 23 ° C.). After stirring until the infrared absorption spectrum of 2260 cm ^-1 disappeared, an 80 mass% MEK / MeOH solution of the target compound urethane acrylate UA3 was obtained.

[Production Example 5] Production of urethane acrylate UA4 10 g of (a1-1) and 3.73 g of adduct-type polyisocyanate (a2-4) are charged in a screw tube so that the number of OH groups / the number of NCO groups = 1. Further, 0.14 g of DOTDD [0.01 times the total mass of (a1-1) and (a2-4)], and 3.47 g of MEK were charged. The obtained mixture was stirred using a stirrer chip at room temperature (approximately 23 ° C.) until the infrared absorption spectrum of 2260 cm ^-1 showing an isocyanate group disappeared, and then an 80 mass% MEK solution of urethane acrylate UA4 as the target compound. Got

[Examples 1 to 4, Comparative Examples 1 to 3]
Each component shown in Table 1 was mixed to prepare a curable composition having a solid content concentration shown in Table 1. Here, the solid content refers to a component other than the solvent. Further, in Table 1, [part] represents [mass part]. The urethane acrylate and the surface modifier in Table 1 each represent a solid content.

These curable compositions were applied on an A4 size double-sided easy-adhesive PET film [Toray Industries, Inc. Lumirror (trademark registration) U403, thickness 100 μm] with a bar coater to obtain a coating film. The coating was dried in an oven at 80 ° C. for 3 minutes to remove the solvent. The obtained film was exposed to UV light having an exposure amount of 300 mJ / cm ² under a nitrogen atmosphere to prepare a hard coat film having a hard coat layer (cured film).

The homogeneity of each curable composition and the scratch resistance and stretchability of the obtained hard coat film were evaluated. The evaluation procedure is shown below. The results are also shown in Table 2.
[Composition homogeneity]
The appearance of the curable composition 2 hours after the preparation was visually confirmed and evaluated according to the following criteria.
A: Clear solution (no suspended matter or sediment)
C: There are both floating substances and sediments [scratch resistance]
The surface of the hard coat layer of the obtained hard coat film was subjected to the load shown in Table 2 with steel wool [BONSTAR (registered trademark) # 0000 (ultra-fine)] attached to a reciprocating wear tester, and the stroke was 60 mm. I rubbed it 10 times. Then, the degree of scratches in the region excluding the range of 5 mm at both ends of the stroke of 60 mm was visually confirmed and evaluated according to the following criteria A, B and C. Assuming actual use as a hard coat layer, it is required to be at least B, and preferably A.
A: No scratches (0 scratches)
B: Scratches (1 to 4 scratches with a length of less than 5 mm)
C: Scratches (5 or more scratches with a length of less than 5 mm, or 1 or more scratches with a length of 5 mm or more)
[Stretchability]
The obtained hard coat film was cut into a rectangle having a length of 60 mm and a width of 10 mm to prepare a test piece. Attached to the grip of the universal testing machine so as to grab 20 mm from both ends in the longitudinal direction of the test piece, and the draw ratio (= (increase in distance between grips) ÷ (distance between grips) x 100) is 4%. A tensile test was performed in 1% increments so as to be 5% and 6%. The hardcourt film after the tensile test was visually observed to confirm the maximum draw ratio in which no crack was generated in the hardcourt layer of the test piece. The stretchability of Comparative Example 1 was set to stretchability 100, and the stretchability was calculated based on this.

As shown in Table 1, the curable compositions of Examples 1 to 4 are the compound represented by the formula [1'], the compound represented by the formula [2'], or the above-mentioned compound represented by the formula [2'] as an isocyanate compound. Urethane acrylates UA1, UA2 or UA3 obtained using the compound represented by the formula [3'], and perfluoropolyether having an acryloyl group at both ends of the molecular chain as a surface modifier via urethane bonds. It contains SM1 or SM2. On the other hand, the curable composition of Comparative Example 1 is a urethane acrylate UA4 obtained by using an adduct-form polyisocyanate, which is a compound not represented by the above formulas [1'] to [3'], as an isocyanate compound, and surface modification. It contains SM1 as a pledge agent. Then, as shown in Table 2, the hard coat film provided with the hard coat layer obtained from the curable compositions of Examples 1 to 4 is a hard coat layer obtained from the curable composition of Comparative Example 1. Compared with the provided hard coat film, it showed better scratch resistance and stretchability equal to or higher than that of the provided hard coat film.

The adduct structure skeleton of the adduct polyisocyanate, which is a compound not represented by the formulas [1'] to [3'], is easily deformed by an external force because the ether portion in the urethane bond has a high degree of freedom of rotation. Therefore, it is considered that the molecular chain of urethane acrylate UA4 is easily broken and has poor scratch resistance. On the other hand, since the structural skeleton of the isocyanate compound represented by the formulas [1'] to [3'] has a urea bond having no ether moiety, it is not easily deformed by an external force, and the urethane acrylate UA1 to UA1 to UA3 is considered to have excellent scratch resistance. Among them, a hard having a hard coat layer obtained from the curable compositions of Examples 1 and 4, which contains urethane acrylate UA1 obtained by using the compound represented by the above formula [1'] as an isocyanate compound. The coated film has been shown to be the most stretchable while maintaining excellent scratch resistance. The structure of the isocyanate compound represented by the formula [1'] has both a urethane bond and a urea bond. In addition, the degree of freedom of rotation of the monohydric alcohol residue represented by R ⁰ is high, and it is presumed that the applied external force can be relaxed as thermal energy. Therefore, urethane acrylate UA1 is considered to have the highest stretchability while maintaining excellent scratch resistance.

On the other hand, the curable composition of Comparative Example 2 contains urethane acrylate UA1 and polydimethylsiloxane SM3 having a methacryloyl group at one end as a surface modifier, and the compatibility of the surface modifier SM3 is poor and good. Could not be obtained. Further, the hard coat film provided with the hard coat layer obtained from the curable composition of Comparative Example 3 containing no surface modifier is a hard coat layer obtained from the curable compositions of Examples 1 to 4. It was shown to be inferior in scratch resistance as compared to the hardcourt film provided with.

[Example 5 and Example 6]
Each component shown in Table 3 was mixed to prepare a curable composition having a solid content concentration shown in Table 3. Here, the solid content refers to a component other than the solvent and the dispersion medium. Further, in Table 3, [part] represents [parts by mass] and [%] represents [% by mass]. The urethane acrylate, surface modifier and antistatic agent in Table 3 each represent a solid content.

These curable compositions were applied on an A4 size double-sided easy-adhesive PET film [Toray Industries, Inc. Lumirror (trademark registration) U403, thickness 100 μm] with a bar coater to obtain a coating film. The coating was dried in an oven at 60 ° C. for 3 minutes to remove the solvent. The obtained film is exposed to UV light having an exposure amount of 300 mJ / cm ² under a nitrogen atmosphere to have a hard coat layer (cured film) having a layer thickness (thickness) of about 4 μm. A film was made.

The surface resistance of the obtained hard-coated film was evaluated in addition to the above-mentioned evaluations of [scratch resistance] and [stretchability]. The procedure for surface resistance evaluation is shown below. The results are shown in Table 4.
[Surface resistance]
The hardcoat film is placed on the cash register table of a high resistivity meter with the surface of the hardcoat layer facing up, the probe is pressed against the hardcoat film (hardcoat layer), and the value 10 seconds later is measured three times and averaged. The value was set to the surface resistivity value [Ω / □].

As shown in Tables 3 and 4, a hardcourt film having a hardcoat layer obtained from the curable compositions of Examples 5 and 6 using the antistatic agent d-1 or d-2 is excellent. It was shown to have scratch resistance and stretchability, as well as antistatic properties.

Claims (20)

(A) 100 parts by mass of at least one urethane (meth) acrylate having any one of the partial structures represented by the following formulas [1] to [3].
(B) Radicals at the end of the molecular chain containing a poly (oxyperfluoroalkylene) group by 0.05 parts by mass to 10 parts by mass of a perfluoropolyether having an active energy ray-polymerizable group, and (c) an active energy ray. A curable composition containing 1 part by mass to 20 parts by mass of a polymerization initiator.

(In the above formula, R ¹ , R ² and R ³ each represent a divalent hydrocarbon group having 4 to 15 carbon atoms, and R ⁰ represents a residue of a monohydric alcohol.) The (a) urethane (meth) acrylate comprises a group consisting of a (meth) acrylate compound having at least one (a1) hydroxy group and (a2) a compound represented by the following formulas [1'] to [3']. The curable composition according to claim 1, which is a reaction product with at least one isocyanate compound selected.

(In the above formula, R ⁰ and R ¹ are synonymous with the definition of the above formula [1], R ² is synonymous with the definition of the above formula [2], and R ³ is synonymous with the definition of the above formula [3]. Is.) The curable composition according to claim 2, wherein the isocyanate compound (a2) is a compound represented by the formula [1']. The perfluoropolyether according to any one of claims 1 to 3, wherein the perfluoropolyether has an active energy ray-polymerizable group at the end of the molecular chain containing the poly (oxyperfluoroalkylene) group via a urethane bond. The curable composition according to claim 1. Claims 1 to 4 said that the (b) perfluoropolyether has at least two active energy ray-polymerizable groups at the end of the molecular chain containing the poly (oxyperfluoroalkylene) group via a urethane bond. The curable composition according to any one of the above. Claims 1 to claim that the (b) perfluoropolyether has at least two active energy ray-polymerizable groups at both ends of the molecular chain containing the poly (oxyperfluoroalkylene) group via urethane bonds. Item 2. The curable composition according to any one of Item 5. The poly (oxyperfluoroalkylene) group of the (b) perfluoropolyether has both a repeating unit- [CF ₂ O]-and a repeating unit- [CF ₂ CF ₂ O] -, and these repeating units are used. The curable composition according to any one of claims 1 to 6, which is a group formed by a block bond, a random bond, or a block bond and a random bond. The curable composition according to claim 7, wherein the molecular chain containing the poly (oxyperfluoroalkylene) group has a structure represented by the following formula [4].

(In the above equation [4], n is the total number of the number of repeating units- [CF ₂ CF ₂ O] -and the number of repeating units- [CF ₂ O] -representing an integer of 5 to 30. , The repeating unit- [CF ₂ CF ₂ O]-and the repeating unit- [CF ₂ O] -are bound by a block bond, a random bond, or a block bond and a random bond.) (D) The curable composition according to any one of claims 1 to 8, further comprising 10 parts by mass to 55 parts by mass of an antistatic agent. The curable composition according to claim 9, wherein the (d) antistatic agent contains metal oxide particles. The curable composition according to claim 10, wherein the metal oxide particles contain an oxide of at least one element selected from the group consisting of tin, zinc, and indium. The curable composition according to claim 11, wherein the metal oxide particles contain tin oxide to which a dopant may be added. The curable composition according to any one of claims 10 to 12, wherein the metal oxide particles contain at least one of phosphorus-doped tin oxide and tin oxide whose surface is coated with antimony pentoxide. thing. (E) The curable composition according to any one of claims 1 to 13, further comprising a solvent. A cured film obtained from the curable composition according to any one of claims 1 to 14. A hard-coated film having a hard-coat layer on at least one surface of a film substrate, wherein the hard-coat layer is made of the cured film according to claim 15. A hard-coated film having a hard-coat layer on at least one surface of a film substrate, wherein the hard-coat layer is based on the curable composition according to any one of claims 1 to 14. A hard coat film formed by a method including a step of applying on a material to form a coating film and a step of irradiating the coating film with active energy rays to cure the film. A hard-coated film having a hard coat layer on at least one surface of a film base material, wherein the hard coat layer applies the curable composition according to claim 14 onto the film base material to form a coating film. A hardcourt film formed by a method including a step of removing the solvent from the coating film by heating, and a step of irradiating the coating film with active energy rays to cure the coating film. The hard coat film according to any one of claims 16 to 18, wherein the hard coat layer has a film thickness of 1 μm to 10 μm. A step of applying the curable composition according to any one of claims 1 to 14 onto a film substrate to form a coating film, and a step of irradiating the coating film with active energy rays to cure the coating film. A method for manufacturing a laminate, including.