KR20230147167A - Curable compositions, hard coat films, articles having hard coat films, image display devices, and flexible displays - Google Patents

Abstract

A curable composition containing a polymerizable compound with a molecular weight of 2000 or less, wherein the content of the polymerizable compound with a molecular weight of 2000 or less in the total solid content of the curable composition is 70% by mass or more, and in the molecule, one or more hydrogen bonding groups and three A curable composition comprising a polymerizable compound (a1) having the above (meth)acrylic group, a hydrogen-bonding proton value of 3.5 mol/kg or more, a (meth)acrylic value of 5.0 mol/kg or more, and a molecular weight of 2000 or less, the above curable composition A hard coat film having a hard coat layer containing a cured product of a curable composition, an article including the hard coat film, an image display device, and a flexible display are excellent in pencil hardness and bending resistance, and also have self-healing properties. A curable composition capable of forming a cured film, a hard coat film having a hard coat layer containing a cured product of the curable composition, an article including the hard coat film, and an image display device are provided.

Description

Curable compositions, hard coat films, articles having hard coat films, image display devices, and flexible displays

The present invention relates to curable compositions, hard coat films, articles with hard coat films, image display devices, and flexible displays.

A curable composition is a composition that is cured by irradiation or heating of active energy rays such as ultraviolet rays. For example, a cured film can be formed by applying a curable composition on a substrate and curing it. In image display devices such as liquid crystal display (LCD), plasma display panel (PDP), electroluminescence display (ELD), micro LED (Light Emitting Diode), and micro OLED (Organic Light Emitting Diode), the display surface In order to prevent scratches, it is suitable to provide an optical film (hard coat film) having a hard coat layer on the substrate, and a curable composition is used as a composition for forming the hard coat layer to form the hard coat layer.

For example, Patent Document 1 describes a curable composition containing a reactive (meth)acrylate polymer having a urethane group, a polymerization initiator, and a reactive monomer. According to Patent Document 1, it is described that a cured film excellent in surface hardness and flexibility can be formed using the curable composition.

Additionally, Patent Document 2 describes a photosensitive resin composition used for forming pixels of a solid-state imaging device containing a monomer having a urethane group, etc.

Patent Document 1: International Publication No. 2009/142237 Patent Document 2: Japanese Patent Publication No. 2010-49029

However, there is a demand for a curable composition that can form a cured film with superior surface hardness and bending resistance. In addition, there is also a demand for a curable composition that can form a cured film with a self-repairing function (self-healing property) even when damage occurs.

The object of the present invention is to provide a curable composition capable of forming a cured film that is excellent in pencil hardness and bending resistance and has self-healing properties, a hard coat film having a hard coat layer containing a cured product of the curable composition, and The object is to provide articles with hard coat films, image display devices, and flexible displays.

The present inventors conducted intensive studies and found that the above problem can be solved by the following means.

<1>

A curable composition containing a polymerizable compound having a molecular weight of 2000 or less,

The content of the polymerizable compound having a molecular weight of 2000 or less in the total solid content of the curable composition is 70% by mass or more,

Polymerizable, having one or more hydrogen-bonding groups and three or more (meth)acrylic groups in the molecule, a hydrogen-bonding proton value of 3.5 mol/kg or more, a (meth)acrylic value of 5.0 mol/kg or more, and a molecular weight of 2000 or less. A curable composition comprising compound (a1).

<2>

The curable composition according to <1>, wherein the sum of the hydrogen-bonded proton value and the (meth)acrylic value of the polymerizable compound (a1) is 10.5 mol/kg or more.

<3>

The curable composition according to <1> or <2>, wherein the curable composition is cured under the following curing conditions, the elastic modulus measured under the following measurement conditions is 9.5 GPa or more, and the elongation at break is 10.0% or more.

Curing conditions: On a polyimide substrate with a thickness of 50 μm, the curable composition was applied to a bar so that the thickness after drying was 11 μm, then dried at 120 ° C. for 1 minute, at 80 ° C., illuminance 60 mW / cm ² , irradiation dose 600 mJ / cm. ² is cured with ultraviolet rays to form a cured product.

Measurement conditions: The laminate of the polyimide substrate and the cured product is measured with a maximum load of 50 mN using a micro hardness tester.

<4>

The curable composition according to any one of <1> to <3>, wherein the content of the polymerizable compound (a1) in the total solid content of the curable composition is 51% by mass or more.

<5>

The curable composition according to <3>, wherein the cured product obtained by curing the curable composition under the curing conditions has a transmittance in the wavelength range of 400 to 700 nm of 80% or more at any wavelength.

<6>

Any one of <1> to <5>, wherein the hydrogen bonding group is at least one selected from the group consisting of a urethane group, a thiourethane group, a urea group, a thiourea group, an amide group, and a thioamide group. The curable composition according to the clause.

<7>

The curable composition according to any one of <1> to <6>, wherein the polymerizable compound (a1) is a compound represented by the following general formula (1) or (2).

[Formula 1]

In general formula (1) ^, R represents a ^substituent , represents an atom or a methyl group, m represents an integer from 0 to 2, and n represents an integer from 2 to 4. However, when X represents C, the sum of m and n is 4, and when X represents N, the sum of m and n is 3. When m represents 2, the two R's may be the same or different. A plurality of L ¹ , A, L ² , and Q may each be the same or different.

[Formula 2]

In general formula (2), Z represents a k+w valent linking group, L ³ and L ⁴ each independently represent a single bond or a divalent linking group, A represents a hydrogen bonding group, and Q represents a hydrogen atom or a methyl group. , R represents a substituent, k represents an integer of 2 to 8, and w represents an integer of 0 to 2. A plurality of L ³ , A, L ⁴ , and Q may each be the same or different. When w represents 2, the two R's may be the same or different.

<8>

The curable composition according to any one of <1> to <7>, further comprising at least one compound selected from the group consisting of a fluorine-based compound and a silicone-based compound.

<9>

The curable composition according to any one of <1> to <8>, further comprising a solvent, wherein 80% by mass or more of the solvent is an organic solvent.

<10>

In the cured product obtained by curing the curable composition under the curing conditions, 80 mol% or more of the (meth)acrylic group contained in the curable composition is changed to a group other than the (meth)acrylic group, as described in <3>. Curable composition.

<11>

Using a laminate of the polyimide substrate and the cured product obtained by curing the curable composition under the curing conditions, the 180° bending test was repeated 10,000 times with the polyimide substrate facing outward at a radius of curvature of 1.5 mm. The curable composition according to <3>, which does not generate cracks.

<12>

When a bending resistance test was conducted using a laminate of the polyimide base material and the cured product obtained by curing the curable composition under the above curing conditions using the cylindrical mandrel method with the polyimide base material on the inside, a bending resistance test of 4 mm in diameter was performed. The curable composition according to <3>, wherein cracks do not occur with a mandrel.

<13>

A hard coat film having a base material and a hard coat layer containing a cured product of the curable composition according to any one of <1> to <12>.

<14>

The hard coat film according to <13>, wherein the transmittance of the hard coat film in the wavelength range of 450 to 700 nm is 80% or more at any wavelength.

<15>

<13>, wherein the substrate contains at least one polymer selected from the group consisting of polyimide, polyaramid, polyethylene terephthalate, polycarbonate, polyethylene naphthalate, polyurethane, acrylic resin, and cellulose resin. Or the hard coat film described in <14>.

<16>

An article provided with the hard coat film according to any one of <13> to <15>.

<17>

An image display device comprising the hard coat film according to any one of <13> to <15> as a surface protection film.

<18>

A flexible display comprising the hard coat film according to any one of <13> to <15> as a surface protection film.

According to the present invention, a curable composition capable of forming a cured film that is excellent in pencil hardness and bending resistance and has self-healing properties, a hard coat film having a hard coat layer containing a cured product of the curable composition, and the hard coat. Articles equipped with coat films, image display devices, and flexible displays can be provided.

Hereinafter, modes for carrying out the present invention will be described in detail, but the present invention is not limited to these. In addition, in this specification, when a numerical value represents a physical property value, a characteristic value, etc., the description "(numerical value 1) to (numerical value 2)" indicates "(numerical value 1) or more and (numerical value 2) or less." In addition, in this specification, the description "(meth)acrylate" means "at least one of acrylate and methacrylate." The same applies to “(meth)acrylic acid,” “(meth)acryloyl,” “(meth)acrylamide,” and “(meth)acryloyloxy.”

[Curable composition]

The curable composition of the present invention,

A curable composition containing a polymerizable compound having a molecular weight of 2000 or less,

The content of a polymerizable compound with a molecular weight of 2000 or less in the total solid content of the curable composition is 70% by mass or more,

Polymerizable, having one or more hydrogen-bonding groups and three or more (meth)acrylic groups in the molecule, a hydrogen-bonding proton value of 3.5 mol/kg or more, a (meth)acrylic value of 5.0 mol/kg or more, and a molecular weight of 2000 or less. It is a curable composition containing compound (a1).

"Polymerization that has one or more hydrogen bonding groups and three or more (meth)acrylic groups in the molecule, a hydrogen bonding proton value of 3.5 mol/kg or more, a (meth)acrylic value of 5.0 mol/kg or more, and a molecular weight of 2000 or less. “Polymerizable compound (a1)” is also called “polymerizable compound (a1).”

<Polymerizable compound (a1)>

The polymerizable compound (a1) has one or more hydrogen-bonding groups and three or more (meth)acrylic groups in the molecule, a hydrogen-bonding proton value of 3.5 mol/kg or more, and a (meth)acrylic value of 5.0 mol/kg or more. and is a polymerizable compound with a molecular weight of 2000 or less.

Hereinafter, polymerizable compound (a1) will be described.

(hydrogen bonding group)

Polymerizable compound (a1) has one or more hydrogen bonding groups in the molecule.

A hydrogen bondable group is a group containing a hydrogen atom (proton) that can form a hydrogen bond. A hydrogen atom that can form a hydrogen bond is a hydrogen atom that is covalently bonded to an atom with high electronegativity, and can form a hydrogen bond with a nearby nitrogen atom or oxygen atom.

The hydrogen bonding group contained in the polymerizable compound (a1) is not particularly limited, and generally known hydrogen bonding groups may be used.

The hydrogen bonding group of the polymerizable compound (a1) is preferably at least one selected from the group consisting of a urethane group, a thiourethane group, a urea group, a thiourea group, an amide group, and a thioamide group, It is more preferable that it is at least one selected from the group consisting of a urethane group, a urea group, and an amide group, more preferably a urethane group or a urea group, and particularly preferably a urea group.

In the present invention, an amide group refers to a divalent linking group represented by -NH-C(=O)-, and a urethane group refers to a divalent linking group expressed by -NH-C(=O)-O-, and urea A group refers to a divalent linking group represented by -NH-C(=O)-NH-, a thiourethane group refers to a divalent linking group expressed by -NH-C(=S)-O-, and a thiourea group refers to a divalent linking group represented by -NH-C(=S)-O-. , represents a divalent linking group represented by -NH-C(=S)-NH-, and thioamide group shall represent a divalent linking group represented by -NH-C(=S)-.

(Hydrogen bonding proton value)

The hydrogen bondable proton number of polymerizable compound (a1) is 3.5 mol/kg or more.

The hydrogen bondable proton number represents the density of hydrogen atoms (protons) that can form hydrogen bonds in a compound, and is calculated from the following formula (i).

Hydrogen bonding proton value = amount of substance (mol) of hydrogen atoms (protons) that can form hydrogen bonds in one molecule of a compound/mass of one molecule of a compound (kg)... (i)

In addition, the number of hydrogen atoms capable of forming hydrogen bonds in the amide group and thioamide group is 1, the number of hydrogen atoms capable of forming hydrogen bonds in the urethane group and thiourethane group is 1, The number of hydrogen atoms that can form hydrogen bonds contained in the urea group and thiourea group is 2.

In the case where the polymerizable compound (a1) is a polymer having structural units, a method for calculating the hydrogen bondable proton number will be explained.

A structural unit is a repeating unit. For example, when polymerizable compound (a1) is a polymer formed by polymerizing only one type of monomer, polymerizable compound (a1) has one type of structural unit and two types. In the case of a monomer copolymer, there are two types of structural units.

When the polymerizable compound (a1) has one type of structural unit, the hydrogen bonding proton number of the polymeric compound (a1) is the hydrogen bonding value in one structural unit calculated by the above formula (i).

When the polymerizable compound (a1) has multiple types of structural units, the hydrogen bonding proton value of each structural unit calculated by the above formula (i) The total sum (average mole fraction) of the values multiplied by the composition ratio (mol%) and divided by 100 is taken as the hydrogen bonding proton value of the polymerizable compound (a1).

Specifically, when the polymerizable compound (a1) has two types of structural units (structural unit 1 and structural unit 2), the hydrogen bonding proton number of the polymeric compound (a1) is calculated from the following formula (iiA): It is calculated.

Hydrogen bonding proton value = H ₁ (hydrogen bonding proton value of structural unit 1) × W ₁ (composition ratio (mol%) of structural unit 1)/100 + H ₂ (hydrogen bonding proton value of structural unit ₂ ) (Composition ratio (mol%) of structural unit 2)/100… (iiA)

Additionally, the polymerizable compound (a1) contains structural unit 1, structural unit 2,... When it has a structural unit

Hydrogen bonding proton value = H ₁ (hydrogen bonding proton value of structural unit 1) × W ₁ (composition ratio (mol%) of structural unit 1)/100 + H ₂ (hydrogen bonding proton value of structural unit ₂ ) (Composition ratio (mol%) of structural unit 2)/100+... _{H _} (iiB)

The hydrogen bondable proton number in the polymerizable compound (a1) is 3.5 mol/kg or more. Because this makes it possible to increase the density of hydrogen bonds formed by the polymerizable compound (a1), it is assumed that the hardness (pencil hardness) of the surface of the cured film formed by curing the curable composition of the present invention can be increased. In addition, since hydrogen bonds can be reversibly dissociated and reformed, the stress during deformation can be released through the dissociation of hydrogen bonds, and the hydrogen bonds are reformed after the structural change, providing bending resistance to the cured film. and self-healing properties. In particular, for a hard coat film having a base material and a hard coat layer containing a curable cured material, excellent bending resistance even in a bending resistance test (outward bending test) conducted with the base material on the inside and the hard coat layer on the outside. It is assumed that it can represent .

The hydrogen bonding proton number in the polymerizable compound (a1) is 3.5 mol/kg or more, preferably 4.0 mol/kg or more, more preferably 5.0 mol/kg or more, and still more preferably 6.0 mol/kg or more. .

In addition, from the viewpoint of improving solubility and suppressing the generation of aggregates during film formation, the hydrogen bonding proton number in the polymerizable compound (a1) is preferably 20.0 mol/kg or less, and 17.5 mol/kg or less. More preferably, it is more preferably 15.0 mol/kg or less, and even more preferably 12.5 mol/kg or less.

((meth)acrylic)

Polymerizable compound (a1) has three or more (meth)acrylic groups in the molecule. That is, the polymerizable compound (a1) contains at least a group (a group represented by the following general formula (T)) selected from the group consisting of an acrylic group (acryloyl group) and a methacryl group (methacryloyl group) in the molecule. I have 3.

[Formula 3]

In general formula (T), Q ¹ represents a hydrogen atom or a methyl group, and * represents a bonding position.

In general formula (T), when Q ¹ is a hydrogen atom, it is an acrylic group, and when Q ¹ is a methyl group, it is a methacryl group.

In general formula (T), * indicates a bonding position, but the type of atom bonded to * is not particularly limited. For example, when * bonds to an oxygen atom, the group represented by the general formula (T) including this oxygen atom becomes a (meth)acryloyloxy group. In addition, when * is bonded to a nitrogen atom (a nitrogen atom bonded to a hydrogen atom or a substituent), the group represented by the general formula (T) including this nitrogen atom is a (meth)acryloylamino group ((meth)acrylate becomes an amide group).

In addition, the (meth)acrylamide group contains an amide group and also corresponds to a hydrogen bonding group.

The (meth)acrylic value represents the density of (meth)acrylic groups in the compound, and is calculated from the following formula (iii).

(Meth)acrylic value = Amount of substance of (meth)acrylic group in 1 molecule of compound (mol)/Mass of 1 molecule of compound (kg)… (iii)

In the case where the polymerizable compound (a1) is a polymer having structural units, a method for determining the (meth)acrylic value will be explained.

When the polymerizable compound (a1) is a polymer having one type of structural unit, the (meth)acrylic value calculated for one structural unit is taken as the (meth)acrylic value of the polymeric compound (a1).

When the polymerizable compound (a1) has multiple types of structural units, the (meth)acrylic value in each structural unit calculated by the formula (iii) above is equal to each structural unit in the polymeric compound (a1). The total sum (average mole fraction) of the values multiplied by the composition ratio (mol%) and divided by 100 is taken as the (meth)acrylic value of the polymerizable compound (a1).

Specifically, when the polymerizable compound (a1) has two types of structural units (structural unit 1 and structural unit 2), the (meth)acrylic value of the polymeric compound (a1) is calculated from the following formula (ivA): It is calculated.

(meth)acrylic value = C ₁ ((meth)acrylic value of structural unit 1) × W ₁ (composition ratio (mol%) of structural unit 1) / 100 + C ₂ ((meth)acrylic value of structural unit 2) × W ₂ (Composition ratio (mol%) of structural unit 2)/100… (ivA)

In addition, when the polymerizable compound (a1) has structural unit 1, structural unit 2,... structural unit It is calculated from the following formula (ivB).

(meth)acrylic value = C ₁ ((meth)acrylic value of structural unit 1) × W ₁ (composition ratio (mol%) of structural unit 1) / 100 + C ₂ ((meth)acrylic value of structural unit 2) × W ₂ (Composition ratio (mol%) of structural unit 2)/100+... Cx ((meth) _acrylic of structural unit (ivB)

The (meth)acrylic value of the polymerizable compound (a1) is 5.0 mol/kg or more, preferably 5.3 mol/kg or more, and more preferably 5.6 mol/kg or more.

The (meth)acrylic value of the polymerizable compound (a1) is determined by dissolving a sample in an appropriate solvent and adding a certain amount of thiol that quantitatively reacts with the (meth)acrylic group, thereby causing en-thiol reaction, thereby producing the thiol consumed. It is possible to guess from Ollyang. The amount of thiol consumed can be quantified by NMR (Nuclear Magnetic Resonance) or GC (Gas Chromatograph).

The number of (meth)acrylic groups in the polymerizable compound (a1) is preferably 3 to 20, more preferably 3 to 8, more preferably 3 to 6, and especially preferably 3 to 4. do.

(Sum of hydrogen bondable proton value and (meth)acrylic value)

The sum of the hydrogen bondable proton value and (meth)acrylic value of the polymerizable compound (a1) is not particularly limited, but is preferably 10.5 mol/kg or more, more preferably 11.0 mol/kg or more, and 11.5 mol/kg or more. It is more preferable, and it is especially preferable that it is 12.0 mol/kg or more. It is preferable that the sum of the hydrogen bondable proton value and (meth)acrylic value of the polymeric compound (a1) is 10.5 mol/kg or more from the viewpoint of increasing the elastic modulus and increasing surface hardness.

(Ratio of hydrogen bondable proton number to (meth)acrylic number)

The ratio between the hydrogen-bondable proton number and the (meth)acrylic number of the polymerizable compound (a1) is not particularly limited, but the hydrogen-bondable proton number/(meth)acrylic number is preferably 0.25 to 4.0, and more preferably 0.35 to 3.5. Preferred, it is more preferable that it is 0.45 or more and 3.0 or less, it is especially preferable that it is 0.55 or more and 2.5 or less, and it is most preferable that it is 0.60 or more and 2.0 or less.

(Molecular Weight)

The molecular weight of the polymerizable compound (a1) is 2000 or less, preferably 1500 or less, more preferably 1250 or less, and still more preferably 1000 or less.

(Structure of polymerizable compound (a1))

The structure of the polymerizable compound (a1) is not particularly limited, but it is preferably a compound represented by the following general formula (1) or (2).

[Formula 4]

In general formula (1) ^, R represents a ^substituent , represents an atom or a methyl group, m represents an integer from 0 to 2, and n represents an integer from 2 to 4. However, when X represents C, the sum of m and n is 4, and when X represents N, the sum of m and n is 3. When m represents 2, the two R's may be the same or different. A plurality of L ¹ , A, L ² , and Q may each be the same or different.

[Formula 5]

In general formula (2), Z represents a k+w valent linking group, L ³ and L ⁴ each independently represent a single bond or a divalent linking group, A represents a hydrogen bonding group, and Q represents a hydrogen atom or a methyl group. , R represents a substituent, k represents an integer of 2 to 8, and w represents an integer of 0 to 2. A plurality of L ³ , A, L ⁴ , and Q may each be the same or different. When w represents 2, the two R's may be the same or different.

In General Formula (1), the substituent represented by R is not particularly limited, but examples include an alkyl group (e.g., 1 to 10 carbon atoms), an aryl group (e.g., 6 to 20 carbon atoms), and a cycloalkyl group (e.g., Carbon number 3 to 10), alkenyl group (e.g. carbon number 2 to 10), alkynyl group (e.g. carbon number 2 to 10), halogen atom, alkyloxy group (e.g. carbon number 1 to 10), aryl oxide group (e.g., carbon atoms 6 to 20), alkyloxycarbonyl group (e.g., carbon atoms 2 to 10), aryloxycarbonyl group (e.g., carbon atoms 7 to 20), alkylcarbonyloxy group (e.g., carbon atoms 2 to 20), 10), arylcarbonyloxy group (for example, 7 to 20 carbon atoms), heterocyclic group (for example, 2 to 10 carbon atoms), hydroxy group, cyano group, nitro group, etc.

In General Formula (1), when L ¹ and L ² represent a divalent linking group, the divalent linking group is not particularly limited, but includes, for example, an alkylene group (for example, having 1 to 10 carbon atoms), a cycloalkylene group (for example, For example, 3 to 10 carbon atoms), alkenylene group (for example, 2 to 10 carbon atoms), arylene group (for example, 6 to 20 carbon atoms), divalent heterocyclic group (for example, 2 to 10 carbon atoms), -O-, A divalent linking group such as -SO ₂ -, -CO-, -S-, or a combination of a plurality thereof is preferred. L ¹ and L ² may have a substituent. There is no particular limitation on the substituent, and for example, the substituent described as the substituent represented by R in the above-mentioned general formula (1), (meth)acryl group, (meth)acryloyloxy group, (meth)acrylamide group, etc. I can hear it.

In General Formula (1), A represents a hydrogen bonding group, and is preferably at least one selected from the group consisting of a urethane group, a thiourethane group, a urea group, a thiourea group, an amide group, and a thioamide group. It is more preferable that it is at least one selected from the group consisting of a urethane group, a urea group, and an amide group, and more preferably a urea group.

In General Formula (1), Q represents a hydrogen atom or a methyl group, and preferably represents a hydrogen atom.

In General Formula (1), m represents an integer of 0 to 2, and preferably represents 0 or 1.

In General Formula (2), the k+w linking group represented by Z is not particularly limited, but may be a chain hydrocarbon group (for example, having 2 to 10 carbon atoms) which may have a hetero atom in the chain, or a hetero atom as a reduction. It is preferable that it is an optional cyclic hydrocarbon group (for example, having 2 to 10 carbon atoms). Examples of the hetero atom include an oxygen atom, a nitrogen atom, and a sulfur atom, with the oxygen atom being preferable. A substituent may be bonded to the chain hydrocarbon group. A substituent may be bonded to the reducing carbon atom of the cyclic hydrocarbon group, or an oxo group (=O) may be bonded to it. There is no particular limitation on the substituent, and for example, the substituent described as the substituent represented by R in the above-mentioned general formula (1), (meth)acryl group, (meth)acryloyloxy group, (meth)acrylamide group, etc. can be mentioned.

In General Formula (2), when L ³ and L ⁴ represent a divalent linking group, the divalent linking group is not particularly limited, but includes, for example, an alkylene group (for example, having 1 to 10 carbon atoms), a cycloalkylene group (for example, For example, 3 to 10 carbon atoms), alkenylene group (for example, 2 to 10 carbon atoms), arylene group (for example, 6 to 20 carbon atoms), divalent heterocyclic group (for example, 2 to 10 carbon atoms), -O-, A divalent linking group such as -SO ₂ -, -CO-, -S-, or a combination of a plurality thereof is preferred. L ³ and L ⁴ may have a substituent. There is no particular limitation on the substituent, and for example, the substituent described as the substituent represented by R in the above-mentioned general formula (1), (meth)acryl group, (meth)acryloyloxy group, (meth)acrylamide group, etc. I can hear it.

In general formula (2), A represents a hydrogen bonding group, and is preferably at least one selected from the group consisting of a urethane group, a thiourethane group, a urea group, a thiourea group, an amide group, and a thioamide group. It is more preferable that it is at least one selected from the group consisting of a urethane group, a urea group, and an amide group, and more preferably a urea group.

In General Formula (2), Q represents a hydrogen atom or a methyl group, and preferably represents a hydrogen atom.

R in General Formula (2) has the same meaning as R in General Formula (1), and the specific examples and preferred ranges are the same.

In General Formula (2), k represents an integer of 2 to 8, and preferably represents an integer of 4 to 8.

Specific examples of polymerizable compound (a1) are shown below, but the present invention is not limited to these.

[Formula 6]

[Formula 7]

[Formula 8]

[Formula 9]

[Formula 10]

In order to synthesize a compound having a urethane group among the polymerizable compounds (a1), a monoisocythane having a (meth)acrylic group in the molecule is added to the primary hydroxyl group of the compound having at least one primary hydroxyl group in the molecule. It is prepared so that the molar ratio of the isocyanate group of the anate is 0.7 to 1.5, preferably 0.8 to 1.3, more preferably 0.9 to 1.2, and most preferably 0.95 to 1.1. By setting it to 0.7 or more, the ratio of products having unreacted primary hydroxyl groups can be reduced, making purification easier. Additionally, by setting it to 1.5 or less, unintended side reactions are less likely to proceed after completion of the reaction, and the occurrence of gelation can be suppressed.

In order to synthesize a polymerizable compound (a1) having a urea group, a monoisocyanate having a (meth)acryl group in the molecule is added to the primary amino group of the compound having at least one primary amino group in the molecule. It is prepared so that the molar ratio of the isocyanate group is 0.7 to 1.5, preferably 0.8 to 1.3, more preferably 0.9 to 1.2, and most preferably 0.95 to 1.1. By setting it to 0.7 or more, the ratio of products having unreacted primary amino groups can be reduced, making purification easier. Additionally, by setting it to 1.5 or less, unintended side reactions are less likely to proceed after completion of the reaction, and the occurrence of gelation can be suppressed.

In order to synthesize a compound having an amide group among the polymerizable compounds (a1), the acid chloride of an acid chloride compound having a (meth)acryl group in the molecule is added to the primary amino group of the compound having at least one primary amino group in the molecule. It is prepared so that the molar ratio of groups is 0.7 to 1.5, preferably 0.8 to 1.3, more preferably 0.9 to 1.2, and most preferably 0.95 to 1.1. By setting it to 0.7 or more, the ratio of products having unreacted primary amino groups can be reduced, making purification easier. Additionally, by setting it to 1.5 or less, unintended side reactions are less likely to proceed after completion of the reaction, and the occurrence of gelation can be suppressed.

The curable composition of the present invention may contain only one type of polymerizable compound (a1), or may contain two or more types with different structures.

The content of polymerizable compound (a1) in the total solid content of the curable composition of the present invention is preferably 51% by mass or more, more preferably 51 to 100% by mass, further preferably 60 to 100% by mass, and 70% by mass. It is especially preferable that it is ~100 mass%, and it is most preferable that it is 80-100 mass%.

In addition, total solid content means all components other than the solvent.

<Polymerization initiator>

The curable composition of the present invention preferably contains a polymerization initiator, and more preferably contains a radical polymerization initiator.

The polymerization initiator is preferably a radical polymerization initiator. The radical polymerization initiator may be a radical photopolymerization initiator or a radical thermal polymerization initiator, but it is more preferable that the radical photopolymerization initiator is a radical photopolymerization initiator.

Only one type of polymerization initiator may be used, or two or more types with different structures may be used in combination.

The radical photopolymerization initiator may be any that can generate radicals as active species by light irradiation, and known radical photopolymerization initiators can be used without any restrictions. Specific examples include, for example, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethylketal, 4-(2-hydroxyethoxy)phenyl-(2) -Hydroxy-2-propyl)ketone, 1-hydroxycyclohexylphenylketone, 2-methyl-2-morpholino(4-thiomethylphenyl)propan-1-one, 2-benzyl-2-dimethylamino -1-(4-morpholinophenyl)butanone, 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone oligomer, 2-hydroxy-1-{4- Acetophenones such as [4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propan-1-one; 1,2-octanedione, 1-[4-(phenylthio)-, 2-(O-benzoyloxime)], ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)- oxime esters such as 9H-carbazol-3-yl]-, 1-(0-acetyloxime); Benzoins such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether; Benzophenone, o-benzoylbenzoic acid methyl, 4-phenylbenzophenone, 4-benzoyl-4'-methyl-diphenyl sulfide, 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone , 2,4,6-trimethylbenzophenone, 4-benzoyl-N,N-dimethyl-N-[2-(1-oxo-2-propenyloxy)ethyl]benzenemetanaminium bromide, (4 -benzophenones such as benzoylbenzyl)trimethylammonium chloride; 2-Isopropyl thioxanthone, 4-isopropyl thioxanthone, 2,4-diethyl thioxanthone, 2,4-dichlorothioxanthone, 1-chloro-4-propoxy thioxanthone, 2- thioxanthone such as (3-dimethylamino-2-hydroxy)-3,4-dimethyl-9H-thioxanthone-9-one meso chloride; 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide, bis(2,4,6- Acylphosphone oxides such as trimethylbenzoyl)-phenylphosphine oxide; etc. can be mentioned. In addition, as an adjuvant for the radical photopolymerization initiator, triethanolamine, triisopropanolamine, 4,4'-dimethylaminobenzophenone (Michler's ketone), 4,4'-diethylaminobenzophenone, 2 -Dimethylaminoethylbenzoic acid, ethyl 4-dimethylaminobenzoic acid, (n-butoxy)ethyl 4-dimethylaminobenzoic acid, isoamyl 4-dimethylaminobenzoic acid, 2-ethylhexyl 4-dimethylaminobenzoic acid, 2 , 4-diethyl thioxanthone, 2,4-diisopropyl thioxanthone, etc. may be used together.

The above radical photopolymerization initiators and adjuvants can be synthesized by known methods and are also available as commercial products.

The content rate of the polymerization initiator in the curable composition is not particularly limited, but for example, is preferably 0.1 to 100 parts by mass, more preferably 1 to 50 parts by mass, per 100 parts by mass of the polymerizable compound (a1), and 1 to 10 parts by mass. The mass part is more preferable.

<Polymerizable compounds other than polymerizable compound (a1)>

In addition to the polymerizable compound (a1), the curable composition of the present invention may further contain polymerizable compounds other than the polymerizable compound (a1). “Polymerizable compounds other than polymerizable compound (a1)” are also called “compound (b1).”

Compound (b1) is preferably a compound having a radical polymerizable group.

The radical polymerizable group in compound (b1) is not particularly limited, and a generally known radical polymerizable group can be used. Examples of the radical polymerizable group include polymerizable unsaturated groups, and specifically, (meth)acryloyl group, vinyl group, and allyl group, and (meth)acryloyl group is preferable. Additionally, each of the above groups may have a substituent.

Compound (b1) is preferably a compound having two or more (meth)acryloyl groups in one molecule, and more preferably is a compound having three or more (meth)acryloyl groups in one molecule.

The molecular weight of compound (b1) is not particularly limited, and may be a monomer, an oligomer, or a polymer.

The molecular weight of compound (b1) is not particularly limited, but is preferably 2000 or less, more preferably 1500 or less, further preferably 1250 or less, and especially preferably 1000 or less.

Specific examples of the compound (b1) are shown below, but the present invention is not limited to these.

Compounds having two (meth)acryloyl groups in one molecule include neopentyl glycol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, and dipropylene glycol di(meth)acrylate ( Meth)acrylate, tripropylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, hydroxypivalic acid neopentyl glycol di(meth)acrylate, polyethylene glycol die. Suitable examples include (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, and dicyclopentanyl di(meth)acrylate.

Examples of compounds having three or more (meth)acryloyl groups in one molecule include esters of polyhydric alcohols and (meth)acrylic acid. Specifically, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylol ethane tri(meth)acrylate, and ditrimethyl. Allpropane tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, pentaerythritol hexa(meth)acrylate, etc. However, in terms of high crosslinking, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, or mixtures thereof are preferable.

Compound (b1) may be used alone, or two or more types with different structures may be used together.

The content of compound (b1) in the curable composition of the present invention is preferably 0 to 49% by mass, more preferably 0 to 40% by mass, and 0 to 30% by mass, based on the total solid content of the curable composition. It is more preferable, and it is especially preferable that it is 0-20 mass %.

<At least one compound selected from the group consisting of fluorine-based compounds and silicon-based compounds>

The curable composition of the present invention preferably contains at least one compound (hereinafter also referred to as “compound (c1)”) selected from the group consisting of fluorine-based compounds and silicone-based compounds.

Compound (c1) is preferably a compound other than polymerizable compound (a1). In addition, the compound (c1) may be the polymerizable compound (b1) or may be a compound other than the polymerizable compound (b1).

Compound (c1) is preferably a leveling agent.

Compound (c1) may be a low molecular weight compound, or may be an oligomer or polymer.

A fluorine-based leveling agent (fluorine-based compound) has a fluoroaliphatic group and a philophilic group in the same molecule that contribute to affinity for various compositions such as coatings and molding materials when this leveling agent is used as an additive, for example. It is a compound, and such a compound can generally be obtained by copolymerizing a monomer having a fluoroaliphatic group and a monomer having an ophilic group.

Representative examples of monomers having an philophilic group that are copolymerized with monomers having a fluoroaliphatic group include poly(oxyalkylene)acrylate, poly(oxyalkylene)methacrylate, and the like.

Preferred commercially available fluorine-based leveling agents include those that do not have an ionizing radiation hardener and include the Megapak series manufactured by DIC Corporation (MCF350-5, F472, F476, F445, F444, F443, F178, F470, F475, F479, F477, F482). , F486, TF1025, F478, F178K, F-784-F, etc.); Examples include the Aftergent series (FTX218, 250, 245M, 209F, 222F, 245F, 208G, 218G, 240G, 206D, 240D, etc.) manufactured by Neos Co., Ltd., and those having an ionizing radiation hardener manufactured by Daikin Kogyo Co., Ltd. First Optul DAC; DIC Co., Ltd.'s Defensor series (TF3001, TF3000, TF3004, TF3028, TF3027, TF3026, TF3025, etc.), Megapak RS series (RS-71, RS-90, RS-101, RS-102, RS-103, RS-104, RS-105, etc.), but is not limited to these.

Additionally, compounds described in Japanese Patent Application Laid-Open No. 2004-331812 and Japanese Patent Application Publication No. 2004-163610, etc. can also be used.

Preferred examples of silicone-based leveling agents (silicon-based compounds) include polymers or oligomers that contain a plurality of dimethylsilyloxy units as repeating units and have substituents at the terminals and/or side chains. The polymer or oligomer containing dimethylsilyloxy as a repeating unit may also contain structural units other than dimethylsilyloxy. The substituents may be the same or different, and it is preferable that there are two or more substituents. Examples of preferable substituents include groups containing a polyether group, an alkyl group, an aryl group, an aryloxy group, an aryl group, a cinnamoyl group, an oxetanyl group, a fluoroalkyl group, a polyoxyalkylene group, etc.

There is no particular limitation on the number average molecular weight of the silicone-based leveling agent, but it is preferably 100,000 or less, more preferably 50,000 or less, particularly preferably 1,000 to 30,000, and most preferably 1,000 to 20,000.

Examples of preferable silicone-based leveling agents include commercially available silicone-based leveling agents that do not have an ionizing radiation hardener, such as X22-3710, X22-162C, X22-3701E, X22160AS, X22170DX, -176F, X224272, KF8001, X22-2000, etc.; FM4421, FM0425, FMDA26, FS1265, etc. manufactured by Chiso Co., Ltd.; BY16-750, BY16880, BY16848, SF8427, SF8421, SH3746, SH8400, SF3771, SH3749, SH3748, SH8410, etc. manufactured by Toray Dow Corning Co., Ltd.; Momentive Performance Materials Japan TSF series (TSF4460, TSF4440, TSF4445, TSF4450, TSF4446, TSF4453, TSF4452, TSF4730, TSF4770, etc.), FGF502, SILWET series (SILWETL77, SILWETL2780, SILWETL76) 08, SILWETL7001, SILWETL7002, SILWETL7087 , SILWETL7200, SILWETL7210, SILWETL7220, SILWETL7230, SILWETL7500, SILWETL7510, SILWETL7600, SILWETL7602, SILWETL7604, SILWETL7604, SILWETL7605, SILWETL7607, SILWETL7622, SILWETL TL7644, SILWETL7650, SILWETL7657, SILWETL8500, SILWETL8600, SILWETL8610, SILWETL8620, SILWETL720), etc., but are limited to these. It doesn't work.

As having an ionizing radiation hardening machine, X22-163A, X22-173DX, X22-163C, KF101, X22164A, X24-8201, X22174DX, 9,X22245 , X221602, X221603, X22164E, X22164B, X22164C, X22164D, TM0701, etc.; Sylaplane series (FM0725, FM0721, FM7725, FM7721, FM7726, FM7727, etc.) manufactured by Chiso Co., Ltd.; SF8411, SF8413, BY16-152D, BY16-152, BY16-152C, 8388A, etc. manufactured by Toray Dow Corning Co., Ltd.; TEGO Rad2010, 2011, 2100, 2200N, 2300, 2500, 2600, 2700, etc. manufactured by Evonik Degusa Japan Co., Ltd.; BYK3500 manufactured by Big Chemi Japan Co., Ltd.; KNS5300 manufactured by Shin-Etsu Silicone Co., Ltd.; Examples include, but are not limited to, UVHC1105 and UVHC8550 manufactured by Momentive, Performance, Materials, and Japan.

Additionally, a fluorine-containing compound described as a lubricant that may be included in the composition for forming a scratch-resistant layer described later can also be cited as a preferred example of compound (c1).

The content of compound (c1) in the curable composition of the present invention is preferably 0.001 to 5.0% by mass, more preferably 0.005 to 2.0% by mass, and 0.01 to 1.0% by mass, based on the total solid content of the curable composition. Most desirable.

<Solvent>

The curable composition of the present invention may contain a solvent.

The solvent may be an organic solvent or an inorganic solvent (for example, water), but it is preferable that 80% by mass or more of the solvent is an organic solvent, and more preferably, 90% by mass or more of the solvent is an organic solvent. It is more preferable that 80% by mass or more of the solvent is an organic solvent that does not have a hydroxyl group, and it is more preferable that 90% by mass or more of the solvent is an organic solvent that does not have a hydroxyl group.

Organic solvents can be used one type or two or more types mixed in any ratio.

Specific examples of organic solvents include alcohols such as methanol, ethanol, propanol, n-butanol, and i-butanol; Ketones such as acetone, methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone; Cellosolves such as ethyl cellosolve; aromatics such as toluene and xylene; Glycol ethers such as propylene glycol monomethyl ether; Acetic acid esters such as methyl acetate, ethyl acetate, and butyl acetate; Diacetone alcohol, etc. can be mentioned.

The solvent content in the curable composition of the present invention can be appropriately adjusted within a range that can ensure the applicability of the curable composition. For example, it can be 50 to 500 parts by mass, preferably 80 to 200 parts by mass, based on 100 parts by mass of the total solid content of the curable composition.

The curable composition usually takes the form of a liquid.

The solid content concentration of the curable composition is usually about 10 to 90 mass%, preferably 20 to 80 mass%, and particularly preferably 40 to 70 mass%.

<Other ingredients>

The curable composition of the present invention may contain components other than the above, and may contain, for example, inorganic fine particles, dispersants, antifouling agents, antistatic agents, ultraviolet absorbers, antioxidants, etc.

The curable composition of the present invention can be prepared by mixing the various components described above simultaneously or sequentially in any order. The preparation method is not particularly limited, and a known stirrer or the like can be used for preparation.

The curable composition of the present invention is preferably cured under the following curing conditions and has an elastic modulus of 9.5 GPa or more and an elongation at break of 10.0% or more as measured under the following measurement conditions.

The elastic modulus is more preferably 10.0 GPa or more, and further preferably 10.5 GPa or more. The elongation at break is preferably 12.5% or more, and more preferably 15.0% or more.

Curing conditions: On a polyimide substrate with a thickness of 50 μm, the curable composition was applied to a bar so that the thickness after drying was 11 μm, then dried at 120 ° C. for 1 minute, at 80 ° C., illuminance 60 mW / cm ² , irradiation dose 600 mJ / cm ² It is cured with ultraviolet rays to form a cured product.

Measurement conditions: The laminate of the polyimide base material and the cured product is measured with a maximum load of 50 mN using a micro hardness tester.

The polyimide base material used under the above curing conditions refers to a base material containing polyimide, and may contain components other than polyimide. The arithmetic mean value of the maximum elastic modulus (indentation modulus) when measured at a maximum load of 50 mN using a microhardness tester is in the range of 5 to 12 GPa, and the arithmetic mean value of the elongation at break is in the range of 7 to 30%.

The indentation modulus and elongation at break of the substrate are measured by the following methods.

(elasticity modulus)

It was measured under the following conditions using an HM2000 type hardness meter (manufactured by Fisher Instruments, Knoop indenter made by Diamond).

Maximum load: 50mN

Load application time: 10 seconds

Creep: 5 seconds

Unloading time: 10 seconds

Holding time after unloading: 5 seconds

Number of measurements: 10

Additionally, the elastic modulus was calculated from the unloading curve in the above measurement.

The elastic modulus was the average value of 10 measurements.

(Padan believer)

The substrate was cut to 120 mm in length and 10 mm in width, and left to stand at a temperature of 25°C and a relative humidity of 60% for 1 hour, then stretched at a speed of 100%/min with a tensile tester, and the elongation rate at which fracture occurred was examined.

The curable composition of the present invention preferably has a transmittance of 80% or more at any wavelength of 400 to 700 nm, more preferably 85% or more, and still more preferably 90% or more at any wavelength of 400 to 700 nm. And, it is particularly preferable that it is 95% or more.

In the cured product cured under the above curing conditions, it is preferable that 80 mol% or more of the (meth)acrylic groups contained in the curable composition of the present invention are changed to groups other than (meth)acrylic groups. “Changes to a group other than a (meth)acrylic group” indicates that the structure of the (meth)acrylic group has changed due to a reaction, etc., and typically indicates that the (meth)acrylic group is consumed by a polymerization reaction. .

Using the laminate of the polyimide base material and the cured product obtained by curing the curable composition of the present invention under the above curing conditions, a 180° bending test was carried out at a radius of curvature of 1.5 mm with the polyimide base material on the outside (the cured product on the inside). It is preferable that no cracks occur when the process is repeated 10,000 times, more preferably no cracks occur when the process is repeated 100,000 times, and it is more desirable that no cracks occur when the process is repeated 1 million times.

Using a laminate of a polyimide base material and a cured product obtained by curing the curable composition of the present invention under the above curing conditions, a bending resistance test was conducted by the cylindrical mandrel method with the polyimide base material on the inside (the cured product on the outside). It is desirable that no cracks occur with a mandrel with a diameter of 6 mm, it is more desirable that no cracks occur with a mandrel with a diameter of 4 mm, and it is more desirable that no cracks occur with a mandrel with a diameter of 3 mm, and it is more desirable that no cracks occur with a mandrel with a diameter of 2 mm. It is particularly desirable that no cracks occur.

<Content of polymerizable compounds with a molecular weight of 2000 or less>

The content of the polymerizable compound having a molecular weight of 2000 or less in the total solid content of the curable composition of the present invention is 70% by mass or more, preferably 75% by mass or more, and more preferably 80% by mass or more.

A polymerizable compound is a compound having one or more polymerizable groups. The polymerizable compound is preferably a compound having two or more polymerizable groups, and is more preferably a compound having three or more polymerizable groups. The polymerizable compound is more preferably a compound having two or more (meth)acrylic groups, and is particularly preferably a compound having three or more (meth)acrylic groups.

“Polymerizable compound with a molecular weight of 2000 or less” also includes the polymerizable compound (a1) described above.

[Hard coat film]

The present invention also relates to a hard coat film having a base material and a hard coat layer containing a cured product of the curable composition described above.

It is preferable that the hard coat film of this invention has the said hard coat layer on a base material.

<Description>

The base material used for the hard coat film of the present invention preferably has a transmittance in the visible light region of 70% or more, more preferably 80% or more, and still more preferably 90% or more.

(polymer)

The substrate preferably contains a polymer.

As the polymer, a polymer having excellent optical transparency, mechanical strength, thermal stability, etc. is preferred.

The base material is at least one selected from the group consisting of polyimide (imide-based polymer), polyaramid (aramid-based polymer), polyethylene terephthalate, polycarbonate, polyethylene naphthalate, polyurethane, acrylic resin, and cellulose resin. It is preferable to include a polymer of

In particular, amide-based polymers (aromatic polyamides) and imide-based polymers are preferable as substrates because they have a high number of breaks and bends measured by an MIT tester according to JIS (Japanese Industrial Standards) P8115 (2001), and their hardness is relatively high. It can be easily used. For example, aromatic polyamide as in Example 1 of Japanese Patent Publication No. 5699454, polyimide as described in Japanese Patent Publication No. 2015-508345, Japanese Patent Publication No. 2016-521216, and WO2017/014287. It can be preferably used as.

The base material preferably contains at least one type of polymer selected from imide-based polymers and aramid-based polymers.

Additionally, the base material can also be formed as a cured layer of ultraviolet curing type or thermosetting type resin such as acrylic, urethane, acrylic urethane, epoxy, silicone, etc.

(softening material)

The base material may contain a material that further softens the polymer. A softening material refers to a compound that improves the number of fractures and bending, and as a softening material, rubbery elastomers, brittleness modifiers, plasticizers, slide ring polymers, etc. can be used.

Specifically, the softening material described in paragraph numbers [0051] to [0114] of Japanese Patent Application Publication No. 2016-167043 can be suitably used as the softening material.

The softening material may be mixed with the polymer alone or in combination with a plurality of materials as appropriate, or may be used alone or in combination with the softening material as a base material without mixing it with the polymer.

The amount of mixing these softening materials is not particularly limited. A polymer having a sufficient number of fractures and bending times may be used alone as the film base, or the softening materials may be mixed. It may be possible to have the number of breaks and bends.

(Other additives)

Various additives (for example, ultraviolet absorbers, matting agents, antioxidants, peeling accelerators, retardation (optical anisotropy) regulators, etc.) depending on the application can be added to the substrate. They may be solid or oily. That is, there is no particular limitation in terms of its melting point or boiling point. Additionally, the additive may be added at any point in the process of manufacturing the base material, or the additive may be added to the material preparation process in addition to the preparation process. Additionally, the amount of each material added is not particularly limited as long as the function is expressed.

As other additives, the additives described in paragraph numbers [0117] to [0122] in Japanese Patent Application Laid-Open No. 2016-167043 can be suitably used.

The above additives may be used individually, or may be used in combination of two or more types.

(UV absorbent)

Examples of ultraviolet absorbers include benzotriazole compounds, triazine compounds, and benzoxazine compounds. Here, the benzotriazole compound is a compound having a benzotriazole ring, and specific examples include various benzotriazole-based ultraviolet absorbers described in paragraph 0033 of Japanese Patent Application Laid-Open No. 2013-111835. A triazine compound is a compound having a triazine ring, and specific examples include various triazine-based ultraviolet absorbers described in paragraph 0033 of Japanese Patent Application Laid-Open No. 2013-111835. As the benzoxazine compound, for example, those described in paragraph 0031 of Japanese Patent Application Laid-Open No. 2014-209162 can be used. The content of the ultraviolet absorber in the base material is, for example, about 0.1 to 10 parts by mass per 100 parts by mass of the polymer contained in the base material, but is not particularly limited. Additionally, regarding the ultraviolet absorber, paragraph 0032 of Japanese Patent Application Laid-Open No. 2013-111835 can also be referred to. Additionally, in the present invention, an ultraviolet absorber with high heat resistance and low volatilization is preferred. Examples of such ultraviolet absorbers include UVSORB101 (manufactured by Fujifilm Fine Chemicals Co., Ltd.), TINUVIN 360, TINUVIN 460, TINUVIN 1577 (manufactured by BASF Corporation), LA-F70, LA-31, LA-46 (manufactured by ADEKA Corporation), etc. I can hear it.

From the viewpoint of transparency, the base material preferably has a small difference in refractive index between the flexible material and various additives used in the base material and the polymer.

(Base containing an imide-based polymer)

As a substrate, a substrate containing an imide polymer can be preferably used. As used herein, an imide-based polymer refers to a polymer containing at least one type of repeating structural unit represented by formula (PI), formula (a), formula (a'), and formula (b). Among them, it is preferable from the viewpoint of the strength and transparency of the film that the repeating structural unit represented by the formula (PI) is the main structural unit of the imide polymer. The repeating structural unit represented by the formula (PI) is preferably 40 mol% or more, more preferably 50 mol% or more, and still more preferably 70 mol% or more, based on the total repeating structural units of the imide polymer. , especially preferably 90 mol% or more, and most preferably 98 mol% or more.

[Formula 11]

In formula (PI), G represents a tetravalent organic group, and A represents a divalent organic group. In formula (a), G ² represents a trivalent organic group, and A ² represents a divalent organic group. In formula (a'), G ³ represents a tetravalent organic group, and A ³ represents a divalent organic group. G ⁴ and A ⁴ in formula (b) each represent a divalent organic group.

In formula (PI), the organic group of the tetravalent organic group represented by G (hereinafter sometimes referred to as the organic group of G) includes a group selected from the group consisting of an acyclic aliphatic group, a cyclic aliphatic group, and an aromatic group. there is. The organic group of G is preferably a tetravalent cyclic aliphatic group or a tetravalent aromatic group from the viewpoint of transparency and flexibility of the substrate containing the imide polymer. Examples of the aromatic group include monocyclic aromatic groups, condensed polycyclic aromatic groups, and non-fused polycyclic aromatic groups that have two or more aromatic rings and are connected to each other directly or through a bonding group. From the viewpoint of transparency of the substrate and suppression of coloring, the organic group of G is a cyclic aliphatic group, a cyclic aliphatic group having a fluorine-based substituent, a monocyclic aromatic group having a fluorine-based substituent, a condensed polycyclic aromatic group having a fluorine-based substituent, or a fluorine-based substituent. It is preferable that it is a non-fused polycyclic aromatic group. In this specification, a fluorine-based substituent means a group containing a fluorine atom. The fluorine-based substituent is preferably a fluoro group (fluorine atom, -F) and a perfluoroalkyl group, and more preferably a fluoro group and a trifluoromethyl group.

More specifically, the organic group of G includes, for example, a saturated or unsaturated cycloalkyl group, a saturated or unsaturated heterocycloalkyl group, an aryl group, a heteroaryl group, an arylalkyl group, an alkylaryl group, a heteroalkylaryl group, and, among these, It is selected from groups having any two groups (which may be the same) and which are connected to each other directly or by a linking group. As a linking group, -O-, an alkylene group having 1 to 10 carbon atoms, -SO ₂ -, -CO- or -CO-NR- (R is an alkyl group having 1 to 3 carbon atoms such as a methyl group, ethyl group, or propyl group, or a hydrogen atom represents).

The carbon number of the tetravalent organic group represented by G is usually 2 to 32, preferably 4 to 15, more preferably 5 to 10, and still more preferably 6 to 8. When the organic group of G is a cyclic aliphatic group or an aromatic group, at least one of the carbon atoms constituting these groups may be substituted with a hetero atom. Hetero atoms include O, N, or S.

Specific examples of G include groups represented by the following formula (20), formula (21), formula (22), formula (23), formula (24), formula (25), or formula (26). * in the formula represents a bond. Z in formula (26) is a single bond, -O-, -CH ₂ -, -C(CH ₃ ) ₂ -, -Ar-O-Ar-, -Ar-CH ₂ -Ar-, -Ar-C (CH ₃ ) ₂ -Ar- or -Ar-SO ₂ -Ar-. Ar represents an aryl group having 6 to 20 carbon atoms, and may be, for example, a phenylene group. At least one of the hydrogen atoms of these groups may be substituted with a fluorine-based substituent.

[Formula 12]

In formula (PI), the organic group of the divalent organic group represented by A (hereinafter sometimes referred to as the organic group of A) includes a group selected from the group consisting of an acyclic aliphatic group, a cyclic aliphatic group, and an aromatic group. there is. The divalent organic group represented by A is preferably selected from a divalent cyclic aliphatic group and a divalent aromatic group. Examples of the aromatic group include monocyclic aromatic groups, condensed polycyclic aromatic groups, and non-fused polycyclic aromatic groups having two or more aromatic rings connected directly or through a bonding group. From the viewpoint of transparency of the substrate and suppression of coloring, it is preferable that a fluorine-based substituent is introduced into the organic group of A.

More specifically, the organic group of A includes, for example, a saturated or unsaturated cycloalkyl group, a saturated or unsaturated heterocycloalkyl group, an aryl group, a heteroaryl group, an arylalkyl group, an alkylaryl group, a heteroalkylaryl group, and any of these. It is selected from groups that have two groups (which may be the same) and are connected to each other directly or by a linking group. Examples of the hetero atom include O, N, or S, and examples of the linking group include -O-, an alkylene group having 1 to 10 carbon atoms, -SO ₂ -, -CO-, or -CO-NR- (R is a methyl group, an ethyl group, and an alkyl group having 1 to 3 carbon atoms, such as a propyl group, or a hydrogen atom).

The carbon number of the divalent organic group represented by A is usually 2 to 40, preferably 5 to 32, more preferably 12 to 28, and still more preferably 24 to 27.

Specific examples of A include groups represented by the following formula (30), formula (31), formula (32), formula (33), or formula (34). * in the formula represents a bond. Z ¹ to Z ³ are each independently a single bond, -O-, -CH ₂ -, -C(CH ₃ ) ₂ -, -SO ₂ -, -CO- or -CO-NR- (R is a methyl group , an alkyl group with 1 to 3 carbon atoms, such as an ethyl group or a propyl group, or a hydrogen atom). In the following groups, Z ¹ and Z ² and Z ² and Z ³ are preferably in the meta or para position with respect to each ring, respectively. Moreover, the single bond between Z ¹ and the terminal, the single bond between Z ² and the terminal, and the single bond between Z ³ and the terminal are preferably in the meta or para position, respectively. In one example of A, Z ¹ and Z ³ are -O-, and Z ² is -CH ₂ -, -C(CH ₃ ) ₂ -, or -SO ₂ -. One or two or more hydrogen atoms of these groups may be substituted with a fluorine-based substituent.

[Formula 13]

At least one of the hydrogen atoms constituting at least one of A and G may be substituted with at least one functional group selected from the group consisting of a fluorine-based substituent, a hydroxyl group, a sulfone group, and an alkyl group having 1 to 10 carbon atoms. Moreover, when the organic group of A and the organic group of G are each a cyclic aliphatic group or an aromatic group, it is preferable that at least one of A and G has a fluorine-based substituent, and it is more preferable that both A and G have a fluorine-based substituent. .

G ² in formula (a) is a trivalent organic group. This organic group can be selected from the same groups as the organic group of G in formula (PI) except that it is a trivalent group. Examples of G ² include groups in which any one of the four bonding hands of groups represented by formulas (20) to (26) given as specific examples of G is substituted with a hydrogen atom. A ² in formula (a) can be selected from the same group as A in formula (PI).

G ³ in formula (a') can be selected from the same group as G in formula (PI). A ³ in formula (a') can be selected from the same group as A in formula (PI).

G ⁴ in formula (b) is a divalent organic group. This organic group can be selected from the same groups as the organic group of G in formula (PI) except that it is a divalent group. Examples of G ⁴ include groups in which any two of the four bonding hands of the groups represented by formulas (20) to (26) given as specific examples of G are substituted with hydrogen atoms. A ⁴ in formula (b) can be selected from the same group as A in formula (PI).

The imide-based polymer included in the substrate containing the imide-based polymer includes diamines, tetracarboxylic acid compounds (including tetracarboxylic acid compound analogs such as acid chloride compounds and tetracarboxylic dianhydride) or tricarboxylic acids. It may be a condensation type polymer obtained by polycondensing at least one type of compound (including tricarboxylic acid compound analogs such as acid chloride compounds and tricarboxylic acid anhydrides). Additionally, dicarboxylic acid compounds (including flexible substances such as acid chloride compounds) may be polycondensed. The repeating structural unit represented by formula (PI) or formula (a') is usually derived from diamines and tetracarboxylic acid compounds. The repeating structural unit represented by formula (a) is usually derived from diamines and tricarboxylic acid compounds. The repeating structural unit represented by formula (b) is usually derived from diamines and dicarboxylic acid compounds.

Examples of tetracarboxylic acid compounds include aromatic tetracarboxylic acid compounds, alicyclic tetracarboxylic acid compounds, and acyclic aliphatic tetracarboxylic acid compounds. These may be used in combination of two or more types. The tetracarboxylic acid compound is preferably tetracarboxylic dianhydride. Examples of tetracarboxylic dianhydride include aromatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, and acyclic aliphatic tetracarboxylic dianhydride.

From the viewpoint of the solubility of the imide polymer in a solvent and transparency and flexibility when forming a substrate, the tetracarboxylic acid compound is preferably an alicyclic tetracarboxylic compound or an aromatic tetracarboxylic acid compound. From the viewpoint of transparency and coloring suppression of the substrate containing the imide polymer, the tetracarboxylic acid compound is preferably selected from alicyclic tetracarboxylic acid compounds having a fluorine-based substituent and aromatic tetracarboxylic acid compounds having a fluorine-based substituent. It is more preferable that it is an alicyclic tetracarboxylic acid compound.

Examples of the tricarboxylic acid compound include aromatic tricarboxylic acid, alicyclic tricarboxylic acid, acyclic aliphatic tricarboxylic acid, and their related acid chloride compounds and acid anhydrides. The tricarboxylic acid compound is preferably selected from aromatic tricarboxylic acid, alicyclic tricarboxylic acid, acyclic aliphatic tricarboxylic acid, and acid chloride compounds thereof. Two or more types of tricarboxylic acid compounds may be used together.

From the viewpoint of the solubility of the imide-based polymer in a solvent and the transparency and flexibility when forming a substrate containing the imide-based polymer, the tricarboxylic acid compound is preferably an alicyclic tricarboxylic acid compound or an aromatic tricarboxylic acid compound. From the viewpoint of transparency and coloring suppression of the substrate containing the imide polymer, the tricarboxylic acid compound is more preferably an alicyclic tricarboxylic acid compound having a fluorine-based substituent or an aromatic tricarboxylic acid compound having a fluorine-based substituent.

Examples of the dicarboxylic acid compound include aromatic dicarboxylic acid, alicyclic dicarboxylic acid, acyclic aliphatic dicarboxylic acid, and their related acid chloride compounds and acid anhydrides. The dicarboxylic acid compound is preferably selected from aromatic dicarboxylic acid, alicyclic dicarboxylic acid, acyclic aliphatic dicarboxylic acid, and acid chloride compounds thereof. Two or more types of dicarboxylic acid compounds may be used in combination.

From the viewpoint of the solubility of the imide-based polymer in a solvent and the transparency and flexibility when forming a substrate containing the imide-based polymer, the dicarboxylic acid compound is preferably an alicyclic dicarboxylic acid compound or an aromatic dicarboxylic acid compound. From the viewpoint of transparency and coloring suppression of the substrate containing the imide polymer, the dicarboxylic acid compound is more preferably an alicyclic dicarboxylic acid compound having a fluorine-based substituent or an aromatic dicarboxylic acid compound having a fluorine-based substituent.

Examples of diamines include aromatic diamine, alicyclic diamine, and aliphatic diamine, and two or more types of these may be used in combination. From the viewpoint of the solubility of the imide-based polymer in a solvent and the transparency and flexibility when forming a substrate containing the imide-based polymer, the diamines are preferably selected from alicyclic diamines and aromatic diamines having a fluorine-based substituent. do.

When such an imide-based polymer is used, it has particularly excellent flexibility, high light transmittance (e.g., 85% or more for 550 nm light, preferably 88% or more), and low yellowness (YI value, 5 or less, Preferably 3 or less), and a low haze (1.5% or less, preferably 1.0% or less) is easy to obtain.

The imide-based polymer may be a copolymer containing a plurality of different types of the above repeating structural units. The weight average molecular weight of polyimide-based polymers is usually 10,000 to 500,000. The weight average molecular weight of the imide polymer is preferably 50,000 to 500,000, and more preferably 70,000 to 400,000. The weight average molecular weight is the standard polystyrene equivalent molecular weight measured by Gel Permeation Chromatography (GPC). If the weight average molecular weight of the imide polymer is large, high flexibility tends to be easily obtained. However, if the weight average molecular weight of the imide polymer is excessively large, the viscosity of the varnish increases and processability tends to decrease.

The imide-based polymer may contain a halogen atom such as a fluorine atom that can be introduced by the fluorine-based substituent described above. When the polyimide-based polymer contains a halogen atom, the elastic modulus of the substrate containing the imide-based polymer can be improved and the yellowness can be reduced. As a result, scratches and wrinkles occurring in the hard coat film can be suppressed, and the transparency of the substrate containing the imide polymer can be improved. The halogen atom is preferably a fluorine atom. The content of halogen atoms in the polyimide polymer is preferably 1 to 40% by mass, and more preferably 1 to 30% by mass, based on the mass of the polyimide polymer.

The substrate containing an imide polymer may contain one or two or more types of ultraviolet absorbers. The ultraviolet absorber can be appropriately selected from those commonly used as ultraviolet absorbers in the field of resin materials. The ultraviolet absorber may contain a compound that absorbs light with a wavelength of 400 nm or less. An ultraviolet absorber that can be appropriately combined with an imide-based polymer includes, for example, at least one compound selected from the group consisting of benzophenone-based compounds, salicylate-based compounds, benzotriazole-based compounds, and triazine-based compounds. I can hear it.

In this specification, “based compound” refers to a derivative of the compound to which “based compound” is given. For example, the term “benzophenone-based compound” refers to a compound having benzophenone as the parent skeleton and a substituent bonded to the benzophenone.

The content of the ultraviolet absorber is usually 1 mass% or more, preferably 2 mass% or more, more preferably 3 mass% or more, usually 10 mass% or less, and preferably 8 mass% or more, based on the total mass of the substrate. It is % by mass or less, more preferably 6% by mass or less. By including the ultraviolet absorber in these amounts, the weather resistance of the substrate can be improved.

The substrate containing an imide-based polymer may further contain inorganic materials such as inorganic particles. The inorganic material is preferably a silicon material containing silicon atoms. When the base material containing an imide-based polymer contains an inorganic material such as a silicon material, the tensile modulus of elasticity of the base material containing the imide-based polymer can be easily set to 4.0 GPa or more. However, the method of controlling the tensile modulus of elasticity of a substrate containing an imide polymer is not limited to mixing of inorganic materials.

Examples of silicon materials containing silicon atoms include silica particles, quaternary alkoxysilanes such as tetraethyl orthosilicate (TEOS), and silicon compounds such as silsesquioxane derivatives. Among these silicon materials, silica particles are preferable from the viewpoint of transparency and flexibility of the substrate containing the imide polymer.

The average primary particle diameter of silica particles is usually 100 nm or less. When the average primary particle diameter of the silica particles is 100 nm or less, transparency tends to improve.

The average primary particle diameter of silica particles in a substrate containing an imide polymer can be determined by observation using a transmission electron microscope (TEM). The primary particle diameter of the silica particles can be the normal diameter determined by a transmission electron microscope (TEM). The average primary particle diameter can be obtained by measuring 10 primary particle diameters through TEM observation and finding their average value. The particle distribution of the silica particles before forming the substrate containing the imide polymer can be determined using a commercially available laser diffraction particle size distribution meter.

In a substrate containing an imide-based polymer, the mixing ratio of the imide-based polymer and the inorganic material is preferably 1:9 to 10:0 in mass ratio, with the sum of both being 10, and 3:7 to 10:0. It is more preferable that it is 3:7-8:2, and it is even more preferable that it is 3:7-7:3. The ratio of the inorganic material to the total mass of the imide polymer and the inorganic material is usually 20% by mass or more, preferably 30% by mass or more, usually 90% by mass or less, and preferably 70% by mass or less. If the mixing ratio of the imide polymer and the inorganic material (silicon material) is within the above range, the transparency and mechanical strength of the substrate containing the imide polymer tend to improve. Additionally, the tensile elastic modulus of the substrate containing the imide polymer can be easily set to 4.0 GPa or more.

The substrate containing the imide polymer may further contain components other than the imide polymer and the inorganic material, as long as transparency and flexibility are not significantly impaired. Components other than imide polymers and inorganic materials include, for example, antioxidants, mold release agents, stabilizers, colorants such as bluing agents, flame retardants, lubricants, thickeners, and leveling agents. The proportion of components other than the imide polymer and the inorganic material is preferably more than 0% and 20% by mass or less, more preferably more than 0% and 10% by mass or less, relative to the mass of the base material.

When the substrate containing an imide polymer contains an imide polymer and a silicon material, it is preferable that Si/N, which is the atomic ratio of silicon atoms to nitrogen atoms on at least one side, is 8 or more. This atomic ratio Si/N is determined by evaluating the composition of the base material containing an imide polymer by It is a value calculated from the amount of abundance.

When Si/N on at least one side of the substrate containing the imide polymer is 8 or more, sufficient adhesion to the hard coat layer is obtained. From the viewpoint of adhesion, Si/N is more preferably 9 or more, more preferably 10 or more, preferably 50 or less, and more preferably 40 or less.

(Thickness of substrate)

The substrate is preferably in the form of a film.

The thickness of the base material is more preferably 100 μm or less, more preferably 80 μm or less, and most preferably 50 μm or less. As the thickness of the substrate becomes thinner, the difference in curvature between the front and back surfaces during bending becomes smaller, cracks, etc. are less likely to occur, and fracture of the substrate does not occur even when the substrate is bent multiple times. On the other hand, from the viewpoint of ease of handling of the substrate, the thickness of the substrate is preferably 3 μm or more, more preferably 5 μm or more, and most preferably 15 μm or more.

(Method of producing base material)

The base material may be formed into a film by heat melting a thermoplastic polymer, or may be formed into a film by solution film formation (solvent casting method) from a solution in which the polymer is uniformly dissolved. In the case of heat melt film forming, the above-mentioned softening material and various additives can be added during heat melt. On the other hand, when producing a base material by a solution film forming method, the above-mentioned softening material and various additives can be added to the polymer solution (hereinafter also referred to as dope) in each preparation process. Moreover, the addition may be performed at any time in the dope preparation process, but the process of adding and preparing the additive may be added to the last preparation process of the dope preparation process.

To dry and/or bake the coating film, the coating film may be heated. The heating temperature of the coating film is usually 50 to 350°C. Heating of the coating film may be performed under an inert atmosphere or under reduced pressure. By heating the coating film, the solvent can be evaporated and removed. The base material may be formed by a method including a step of drying the coating film at 50 to 150°C and a step of baking the dried coating film at 180 to 350°C.

Surface treatment may be performed on at least one side of the substrate.

<Hard coat layer>

The hard coat film of the present invention has a hard coat layer containing a cured product of the curable composition of the present invention described above.

The hard coat layer is preferably formed on at least one side of the substrate.

When the hard coat film of the present invention has a scratch-resistant layer described later, it is preferable to have at least one hard coat layer between the base material and the scratch-resistant layer.

(Cured product of curable composition)

The hard coat layer of the hard coat film of the present invention contains a cured product of the curable composition containing the polymerizable compound (a1).

The cured product of the curable composition preferably contains at least a cured product formed by bonding the (meth)acrylic groups of the polymerizable compound (a1) through a polymerization reaction.

The content of the cured product in the hard coat layer of the hard coat film of the present invention is preferably 20 to 100 mass%, more preferably 30 to 100 mass%, and still more preferably 40 to 100 mass%. And, it is particularly preferable that it is 50 to 100% by mass.

(Film thickness of hard coat layer)

The film thickness of the hard coat layer is not particularly limited, but is preferably 0.5 to 50 μm, more preferably 1 to 40 μm, and still more preferably 2 to 30 μm.

The film thickness of the hard coat layer is calculated by observing a cross section of the hard coat film with an optical microscope. A cross-sectional sample can be created by a microtome method using a cross-section cutting device ultra microtome or a cross-section processing method using a focused ion beam (FIB) device.

The transmittance of the hard coat film of the present invention at a wavelength of 450 to 700 nm is preferably 80% or more, more preferably 85% or more, more preferably 90% or more, and especially preferably 95% or more at any wavelength. do.

<Scratch-resistant layer>

It is preferable that the hard coat film of the present invention further has a scratch-resistant layer.

When the hard coat film of the present invention has a scratch-resistant layer, it is preferable to have at least one layer of the scratch-resistant layer on the surface opposite to the base material of the hard coat layer.

The scratch-resistant layer preferably contains a cured product of a composition for forming a scratch-resistant layer containing at least one polymerizable compound, and the above-mentioned compound (b1) is preferable as the polymerizable compound.

The content of the polymerizable compound in the composition for forming a scratch-resistant layer is preferably 80% by mass or more, more preferably 85% by mass or more, and still more preferably 90% by mass or more, based on the total solid content in the composition for forming a scratch-resistant layer.

The composition for forming a scratch-resistant layer preferably contains at least one type of polymerization initiator.

The polymerization initiator is the same as the polymerization initiator that may be contained in the curable composition of the present invention described above.

The content of the polymerization initiator in the composition for forming a scratch-resistant layer is not particularly limited, but for example, it is preferably 0.1 to 200 parts by mass, and more preferably 1 to 50 parts by mass, per 100 parts by mass of the polymerizable compound.

(menstruum)

The composition for forming a scratch-resistant layer may contain a solvent.

The solvent is the same as the solvent that the curable composition of the present invention described above may contain.

The solvent content in the composition for forming a scratch-resistant layer can be appropriately adjusted within a range that can ensure the application suitability of the composition for forming a scratch-resistant layer. For example, it can be 50 to 500 parts by mass, preferably 80 to 200 parts by mass, based on 100 parts by mass of the total solid content of the composition for forming a scratch-resistant layer.

The composition for forming a scratch-resistant layer usually takes the form of a liquid.

The solid content concentration of the composition for forming a scratch-resistant layer is usually about 10 to 90% by mass, preferably about 20 to 80% by mass, and particularly preferably about 40 to 70% by mass.

(Other additives)

The composition for forming a scratch-resistant layer may contain components other than the above, for example, inorganic particles, leveling agent, antifouling agent, antistatic agent, lubricant, solvent, etc.

In particular, it is preferable to contain the following fluorine-containing compounds as a lubricant.

[Fluorinated compound]

The fluorine-containing compound may be any of monomers, oligomers, and polymers. The fluorine-containing compound preferably has a substituent that contributes to bond formation or compatibility with the polymerizable compound in the scratch-resistant layer. These substituents may be the same or different, and it is preferable that there are two or more substituents.

This substituent is preferably a polymerizable group, and may be a polymerizable reactive group exhibiting any one of radical polymerizability, cationic polymerizability, anionic polymerizability, condensation polymerizability, and addition polymerizability. Examples of preferable substituents include acryloyl group and methacrylic group. Examples include diary group, vinyl group, allyl group, cinnamoyl group, epoxy group, oxetanyl group, hydroxyl group, polyoxyalkylene group, carboxyl group, and amino group. Among them, a radical polymerizable group is preferable, and among them, an acryloyl group and a methacryloyl group are particularly preferable.

The fluorine-containing compound may be a polymer or an oligomer with a compound that does not contain a fluorine atom.

The fluorine-containing compound is preferably a fluorine-based compound represented by the following general formula (F).

General formula (F): (R ^f )-[(W)-(R ^A ) _nf ] _mf

(Wherein, R ^f represents a (per)fluoroalkyl group or (per)fluoropolyether group, W represents a single bond or linking group, and R ^A represents a polymerizable unsaturated group. nf represents an integer of 1 to 3. mf represents an integer from 1 to 3.)

In general formula (F), R ^A represents a polymerizable unsaturated group. The polymerizable unsaturated group is preferably a group (i.e., a radical polymerizable group) having an unsaturated bond that can cause a radical polymerization reaction by irradiating active energy rays such as ultraviolet rays or electron beams, such as a (meth)acryloyl group, (meth) An acryloyloxy group, a vinyl group, an allyl group, etc. are mentioned, and (meth)acryloyl group, (meth)acryloyloxy group, and groups in which any hydrogen atom in these groups is replaced with a fluorine atom are preferably used.

In general formula (F), R ^f represents a (per)fluoroalkyl group or a (per)fluoropolyether group.

Here, the (per)fluoroalkyl group represents at least one of a fluoroalkyl group and a perfluoroalkyl group, and the (per)fluoropolyether group represents at least one of a fluoropolyether group and a perfluoropolyether group. Represents type 1. From the viewpoint of scratch resistance, it is preferable that the fluorine content in R ^f is higher.

The (per)fluoroalkyl group is preferably a group having 1 to 20 carbon atoms, and more preferably a group having 1 to 10 carbon atoms.

(Per) fluoroalkyl group has a straight chain structure (e.g. -CF ₂ CF ₃ , -CH ₂ (CF ₂ ) ₄ H, -CH ₂ (CF ₂ ) ₈ CF ₃ , -CH ₂ CH ₂ (CF ₂ ) ₄ H) may be used, and may be a branched structure (e.g. -CH(CF ₃ ) ₂ , -CH ₂ CF(CF ₃ ) ₂ , -CH(CH ₃ )CF ₂ CF ₃ , -CH(CH ₃ )(CF ₂ ) ₅ CF ₂ H) may be used, and may be an alicyclic structure (preferably a 5- or 6-membered ring, for example, a perfluorocyclohexyl group, a perfluorocyclopentyl group, and an alkyl group substituted with these groups).

A (per)fluoropolyether group refers to a case where a (per)fluoroalkyl group has an ether bond, and may be monovalent or may be divalent or more. Examples of the fluoropolyether group include -CH ₂ OCH ₂ CF ₂ CF ₃ , -CH ₂ CH 2 OCH ₂ C ₄ F ₈ H, -CH ₂ CH ₂ OCH _{2 CH 2 C 8} F ₁₇ , -CH ₂ CH ₂ OCF ₂ CF ₂ OCF ₂ CF ₂ H, a fluorocycloalkyl group of 4 to 20 carbon atoms having 4 or more fluorine atoms, etc. Also, examples of the perfluoropolyether group include -(CF ₂ O) _pf -(CF ₂ CF ₂ O) _qf -, -[CF(CF ₃ )CF ₂ O] _pf -[CF(CF ₃ )] _qf -, -(CF ₂ CF ₂ CF ₂ O) _pf -, -(CF ₂ CF ₂ O) _pf -, etc.

The pf and qf each independently represent an integer of 0 to 20. However, pf+qf is an integer greater than 1.

The total of pf and qf is preferably 1 to 83, more preferably 1 to 43, and more preferably 5 to 23.

It is particularly preferable that the fluorine-containing compound has a perfluoropolyether group represented by -(CF ₂ O) _pf -(CF ₂ CF ₂ O) _qf - from the viewpoint of excellent scratch resistance.

The fluorine-containing compound preferably has a perfluoropolyether group and also has a plurality of polymerizable unsaturated groups in one molecule.

In general formula (F), W represents a linking group. Examples of W include an alkylene group, an arylene group, a heteroalkylene group, and a linking group composed of a combination of these groups. These linking groups may also have functional groups such as oxy groups, carbonyl groups, carbonyloxy groups, carbonylimino groups, and sulfonamide groups, or combinations of these groups.

W is preferably an ethylene group, more preferably an ethylene group bonded to a carbonylimino group.

There is no particular limitation on the fluorine atom content of the fluorine-containing compound, but it is preferably 20% by mass or more, more preferably 30 to 70% by mass, and still more preferably 40 to 70% by mass.

Examples of preferred fluorine-containing compounds include R-2020, M-2020, R-3833, M-3833 and Optul DAC (trade names above) manufactured by Daikin Chemical Co., Ltd., and Megapac F-171 and F manufactured by DIC. -172, F-179A, RS-78, RS-90, Defensor MCF-300, and MCF-323 (above product names), but are not limited to these.

From the viewpoint of scratch resistance, in general formula (F), the product of nf and mf (nf×mf) is preferably 2 or more, and more preferably 4 or more.

The weight average molecular weight (Mw) of the fluorinated compound having a polymerizable unsaturated group can be measured using molecular exclusion chromatography, for example, gel permeation chromatography (GPC).

The Mw of the fluorine-containing compound is preferably 400 to 50,000, more preferably 400 to 30,000, and still more preferably 400 to 25,000.

The content of the fluorine-containing compound is preferably 0.01 to 5% by mass, more preferably 0.1 to 5% by mass, more preferably 0.5 to 5% by mass, based on the total solid content in the composition for forming a scratch resistant layer. Mass % is particularly preferred.

The composition for forming a scratch-resistant layer can be prepared by mixing the various components described above simultaneously or sequentially in any order. The preparation method is not particularly limited, and a known stirrer or the like can be used for preparation.

(Cured product of composition for forming scratch-resistant layer)

The scratch-resistant layer preferably contains a cured product of a composition for forming a scratch-resistant layer containing a polymerizable compound, and more preferably, a composition for forming a scratch-resistant layer containing a polymerizable compound having a radical polymerizable group and a radical polymerization initiator. It contains the hardened product of .

The cured product of the composition for forming a scratch-resistant layer preferably contains at least a cured product obtained by polymerization of a radical polymerizable group of a polymerizable compound having a radical polymerizable group.

The content of the cured product of the composition for forming a scratch-resistant layer in the scratch-resistant layer is preferably 60% by mass or more, more preferably 70% by mass or more, and still more preferably 80% by mass or more, relative to the total mass of the scratch-resistant layer.

(Film thickness of scratch-resistant layer)

From the viewpoint of repeated bending resistance, the film thickness of the scratch-resistant layer is preferably less than 3.0 μm, more preferably 0.1 to 2.0 μm, and still more preferably 0.1 to 1.0 μm.

<Method for producing hard coat film>

The manufacturing method of the hard coat film of this invention is demonstrated.

It is preferable that the manufacturing method of the hard coat film of this invention is a manufacturing method including the following processes (I) and (II). Moreover, when the hard coat film has a scratch-resistant layer, it is preferable that the manufacturing method further includes the following steps (III) and (IV).

(I) A process of forming a hard coat layer coating film by applying a curable composition containing a polymerizable compound (a1) onto a substrate.

(II) Process of forming a hard coat layer by curing the hard coat layer coating film

(III) A process of forming a scratch-resistant layer coating film by applying a composition for forming a scratch-resistant layer containing a polymerizable compound on the hard coat layer.

(IV) Process of forming a scratch-resistant layer by curing the scratch-resistant layer coating film

-Process (I)-

Step (I) is a step of applying a curable composition containing the polymerizable compound (a1) onto a substrate to prepare a hard coat layer coating film.

The base material, polymerizable compound (a1), and curable composition are as described above.

The method of applying the curable composition is not particularly limited and any known method can be used. Examples include the dip coat method, air knife coat method, curtain coat method, roller coat method, wire bar coat method, gravure coat method, and die coat method.

-Process (II)-

Step (II) is a step of forming a hard coat layer by curing the hard coat layer coating film. In addition, curing the hard coat layer coating film means polymerizing at least a part of the (meth)acrylic groups of the polymerizable compound (a1) contained in the hard coat layer coating film.

The hard coat layer coating film is preferably cured by irradiation of ionizing radiation or heating.

There is no particular limitation on the type of ionizing radiation, and examples include X-rays, electron beams, ultraviolet rays, visible light, and infrared rays, but ultraviolet rays are preferably used. For example, if the hard coat layer coating is ultraviolet curable, it is preferable to cure the curable compound by irradiating ultraviolet rays at a dose of 10 mJ/cm ² to 2000 mJ/cm ² using an ultraviolet lamp, so that the hard coat film is resistant to scratches on the hard coat layer. In the case of having an upper layer, it is preferable to semi-harden the curable compound. More preferably, it is 50mJ/cm ² to 1800mJ/cm ² , and more preferably 100mJ/cm ² to 1500mJ/cm ² . As ultraviolet lamp types, metal halide lamps, high-pressure mercury lamps, etc. are suitably used.

When curing by heat, there is no particular limit to the temperature, but it is preferably 80°C or higher and 200°C or lower, more preferably 100°C or higher and 180°C or lower, and even more preferably 120°C or higher and 160°C or lower.

The oxygen concentration during curing is preferably 0 to 1.0 volume%, more preferably 0 to 0.1 volume%, and most preferably 0 to 0.05 volume%.

-Process (III)-

Step (III) is a step of forming a scratch-resistant layer coating film by applying a composition for forming a scratch-resistant layer containing a polymerizable compound on the hard coat layer.

The polymerizable compound and the composition for forming a scratch-resistant layer are as described above.

The method of applying the composition for forming a scratch-resistant layer is not particularly limited and any known method can be used. Examples include the dip coat method, air knife coat method, curtain coat method, roller coat method, wire bar coat method, gravure coat method, and die coat method.

-Process (IV)-

Step (IV) is a step of forming a scratch-resistant layer by curing the scratch-resistant layer coating film.

Curing of the scratch-resistant layer coating film is preferably performed by irradiation of ionizing radiation or heating. Irradiation and heating of ionizing radiation are the same as those described in step (II). In addition, curing the scratch-resistant layer coating film means polymerizing at least a part of the polymerizable groups of the polymerizable compound contained in the scratch-resistant layer coating film.

In the present invention, when the hard coat film has a scratch-resistant layer on the hard coat layer, it is preferable to semi-harden the hard coat layer coating in the above step (II). That is, in step (II), the hard coat layer coating film is semi-cured, and then in step (III), the composition for forming a scratch-resistant layer is applied on the semi-cured hard coat layer to form a scratch-resistant layer coating film, and then, In step (IV), it is preferable to completely cure the hard coat layer while curing the scratch-resistant layer coating film. Here, semi-curing the hard coat layer coating film means polymerizing only a portion of the (meth)acrylic groups of the polymerizable compound (a1) contained in the hard coat layer coating film. Semi-hardening of the hard coat layer coating film can be performed by adjusting the irradiation amount of ionizing radiation or the temperature and time of heating.

Drying treatment is performed as necessary between steps (I) and (II), between steps (II) and (III), between steps (III) and steps (IV), or after step (IV). It's okay too. Drying treatment can be performed by spraying warm air, placing in a heating furnace, conveying within the heating furnace, heating using a roller from the side (substrate surface) on which the hard coat layer and the scratch-resistant layer are not provided, etc. The heating temperature may be set to a temperature at which the solvent can be removed by drying, and is not particularly limited. Here, the heating temperature refers to the temperature of warm air or the temperature of the atmosphere within the heating furnace.

The hard coat film of the present invention can be used as a surface protection film for an image display device, for example, as a surface protection film for a foldable device (foldable display). A foldable device is a device employing a flexible display with a deformable display screen, and the device main body (display) can be folded using the deformability of the display screen.

Examples of foldable devices include organic electroluminescence devices.

The present invention also relates to an article provided with the hard coat film.

Moreover, this invention also relates to an image display device equipped with the said hard coat film as a surface protection film.

Furthermore, the present invention also relates to a foldable device provided with the hard coat film as a surface protection film.

Example

Hereinafter, the present invention will be described in more detail through examples, but the scope of the present invention is not to be construed as limited thereto.

<Production of equipment>

(Manufacture of polyimide powder)

After adding 832 g of N,N-dimethylacetamide (DMAc) under a nitrogen stream to a 1 L reactor equipped with a stirrer, nitrogen injection device, dropping funnel, temperature controller, and cooler, the temperature of the reactor was set to 25°C. Here, 64.046 g (0.2 mol) of bistrifluoromethylbenzidine (TFDB) was added and dissolved. While maintaining the obtained solution at 25°C, 31.09 g (0.07 mol) of 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) and 8.83 mol of biphenyltetracarboxylic dianhydride (BPDA) were added. g (0.03 mol) was added and stirred for a certain period of time to cause reaction. After that, 20.302 g (0.1 mol) of terephthaloyl chloride (TPC) was added to obtain a polyamic acid solution with a solid content concentration of 13% by mass. Next, 25.6 g of pyridine and 33.1 g of acetic anhydride were added to this polyamic acid solution, stirred for 30 minutes, stirred for another hour at 70°C, and then cooled to room temperature. 20 L of methanol was added thereto, and the precipitated solid was filtered and pulverized. After that, it was dried in vacuum at 100°C for 6 hours to obtain 111 g of polyimide powder.

(Production of base material S-1)

100 g of the polyimide powder was dissolved in 670 g of N,N-dimethylacetamide (DMAc) to obtain a 13% by mass solution. The obtained solution was casted on a stainless steel plate and dried with hot air at 130°C for 30 minutes. Afterwards, the film is peeled from the stainless steel plate, fixed to the frame with pins, the frame with the film fixed is placed in a vacuum oven, and heated for 2 hours while gradually increasing the heating temperature from 100°C to 300°C, and then gradually cooled. did. After the cooled film was separated from the frame, as a final heat treatment step, it was further heat treated at 300°C for 30 minutes to obtain a base material S-1 made of polyimide film and having a thickness of 50 μm.

<Synthesis of (A1)>

Trimethylolpropane (200 mmol), dibutyltin dilaurate (2 mmol), and dehydrated N,N'-dimethylacetamide (300 mL) were mixed, and 2-metabolite was added using a dropping funnel while stirring at 50°C. Cryloyloxyethyl isocyanate (600 mmol) was added dropwise and stirred at 50°C for 5 hours. The reaction solution was returned to room temperature and added to 1 L of water, and crystals precipitated. After filtration and drying, (A1) was obtained with a yield of 90%.

<Synthesis of (A2) to (A4)>

(A2) to (A4) are synthesized in the same manner except that trimethylolpropane or 2-methacryloyloxyethyl isocyanate is replaced with an alcohol compound or isocyanate compound of the corresponding structure, respectively. did.

<Synthesis of (A5)>

Mix bis(2-aminoethyl)amine (200mmol) and dehydrated acetonitrile (300mL), and add 2-methacryloyloxyethylisocyanate (600mmol) using a dropping funnel while stirring at -5°C. It was added dropwise and stirred at -5°C for 3 hours. After extraction with ethyl acetate and water, and drying the organic layer with magnesium sulfate, the reaction product was separated and purified by column chromatography (developing solvent: ethyl acetate/methanol) to obtain (A5) in a yield of 18%.

<Synthesis of (A6)>

3,3'-Diaminodipropylamine (182 mmol), sodium bicarbonate (450 mmol), water (100 g), and tetrahydrofuran (300 mL) were mixed, and acrylic acid chloride (389 mmol) was added using a dropping funnel while stirring at 0°C. ) was added dropwise and stirred at room temperature for 5 hours. After distilling off tetrahydrofuran under reduced pressure from the obtained reaction mixture, ethyl acetate (200 mL) was added to extract the organic layer four times, and the organic layers were dried collectively over magnesium sulfate. The obtained reaction mixture was separated and purified by column chromatography (eluent: ethyl acetate/methanol) to obtain (A6) in a yield of 40%.

The structures of the polymerizable compounds used in the examples and comparative examples are shown below. (A1) to (A6) are polymerizable compounds (a1), and (RA1) to (RA5) are not polymerizable compounds (a1).

[Formula 14]

[Formula 15]

[Formula 16]

[Formula 17]

[Formula 18]

[Formula 19]

[Formula 20]

[Formula 21]

[Formula 22]

[Formula 23]

[Formula 24]

Table 1 below shows the molecular weight, number of hydrogen-bonding protons in one molecule, hydrogen-bonding proton number, and number of (meth)acrylic groups in one molecule for compounds (A1) to (A6) and (RA1) to (RA5). , (meth)acrylic value, elastic modulus, and elongation at break were described.

The elastic modulus and breaking elongation are the elastic modulus and breaking elongation measured under the following measurement conditions for a cured product obtained by curing the curable composition under the following curing conditions.

(Manufacture of laminate)

The curable composition was applied onto the substrate S-1 so that the film thickness after curing was 11 μm. After application, the coating film was heated at 120°C for 1 minute. Next, under conditions of an oxygen concentration of less than 100 ppm (parts per million), using a high-pressure mercury lamp, ultraviolet rays are irradiated so that the cumulative irradiation amount is 600 mJ/cm ² and the illuminance is 60 mW/cm ² , and then irradiated with ultraviolet rays at 80°C and with an oxygen concentration of 100 ppm. The coating film was completely cured by further irradiating ultraviolet rays with an illumination intensity of 60 mW/cm ² and an irradiation amount of 600 mJ/cm ² using a high-pressure mercury lamp under the following conditions. In this way, a laminate having a polyimide substrate and a film of the cured product was obtained.

In addition, as the curable composition, the curable composition prepared in Examples 1, 3 to 6, and 8 and Comparative Examples 1 to 5 described later were used.

(elasticity modulus)

The polyimide base side of each laminate and the glass were bonded using Aaron Alpha (registered trademark) (manufactured by Toa Kosei Co., Ltd.), and an HM2000 type hardness tester (manufactured by Fisher Instruments, Knoop indenter made by Diamond) was used under the following conditions. It was measured in

Maximum load: 50mN

Load application time: 10 seconds

Creep: 5 seconds

Unloading time: 10 seconds

Holding time after unloading: 5 seconds

Number of measurements: 10

Additionally, the elastic modulus was calculated from the unloading curve in the above measurement.

The elastic modulus was the average value of 10 measurements.

The elastic modulus was evaluated based on the following standards.

A: 10.5 GPa or more, B: 9.5 GPa or more but less than 10.5 GPa, C: 8.5 GPa or more but less than 9.5 GPa, D: Less than 8.5 GPa

(Padan believer)

Each laminate was cut to 120 mm in length and 10 mm in width, and left to stand for 1 hour at a temperature of 25°C and a relative humidity of 60%, then stretched at a speed of 100%/min in a tensile tester, and the elongation at which fracture occurred was examined. did.

The breaking elongation was evaluated based on the following criteria with respect to the elongation rate at which the above-mentioned breaking occurs.

A: 15% or more, B: 10% or more but less than 15%, C: 5% or more but less than 10%, D: less than 5%

(transmittance)

The UV-Vis absorption spectrum was measured using UV-3100 (manufactured by Shimadzu Seisakusho), and the absorption spectrum of the polyimide substrate alone was subtracted. For all samples, the transmittance of the cured product was 80% at any wavelength between 400 and 700 nm. It was confirmed that it was more than %.

[Table 1]

[Example 1]

<Preparation of curable composition>

(Curable composition HC-1)

The content of the following components was adjusted as follows, and they were placed in a mixing tank and stirred. The obtained composition was filtered through a polypropylene filter with a pore diameter of 0.45 μm to obtain curable composition HC-1.

(A1) 47.45 parts by mass

Irgacure 127 (Irg. 127) 2.5 parts by mass

Megapak RS-90 0.05 parts by mass

MIBK (methyl isobutyl ketone) 50.0 parts by mass

Additionally, Irgacure 127 (Irg. 127) is a radical polymerization initiator manufactured by BASF.

Megapak RS-90 is a UV-responsive surface modifier manufactured by DIC.

(Manufacture of hard coat film)

The curable composition HC-1 was applied onto the polyimide substrate S-1 with a thickness of 50 μm using a wire bar #18 so that the film thickness after curing was 11 μm, and a hard coat layer coating film was prepared on the substrate.

Next, the hard coat layer coating film was heated at 120°C for 1 minute. Next, under conditions of an oxygen concentration of less than 100 ppm (parts per million), using a high-pressure mercury lamp, ultraviolet rays are irradiated so that the cumulative irradiation amount is 600 mJ/cm ² and the illuminance is 60 mW/cm ² , and then irradiated with ultraviolet rays at 80°C and with an oxygen concentration of 100 ppm. The hard coat layer coating film was completely cured by further irradiating ultraviolet rays with an illuminance of 60 mW/cm ² and an irradiation amount of 600 mJ/cm ² using a high-pressure mercury lamp under the following conditions. In this way, the hard coat layer coating film was cured to obtain a hard coat film of Example 1 having a hard coat layer (cured product of curable composition HC-1) on a base material.

[Examples 2 to 8, Comparative Examples 1 to 5]

The hard coat films of Examples 2 to 8 and Comparative Examples 1 to 5 were produced in the same manner as in Example 1, except that (A1), which was a polymerizable compound, was changed to the one shown in Table 2 below.

[Comparative Example 6]

The content of the following components was adjusted as follows, and they were placed in a mixing tank and stirred. The obtained composition was filtered through a polypropylene filter with a pore diameter of 0.45 μm to obtain curable composition HC-R6.

Cyclomeric P-ACA (solids concentration 50% by mass) 13.66 parts by mass

(A5) 7.175 parts by mass

(RA1) 3.07 parts by mass

Irgacure 127 (Irg. 127) 0.98 parts by mass

Compound III 1.03 parts by mass

Megapak RS-90 0.01 parts by mass

MIBK 69.82 parts by mass

Polymerization inhibitor (p-methoxyphenol) 0.0051 parts by mass

Cyclomer P-ACA is a polymer with a weight average molecular weight of 30,000 manufactured by Daicel. Cyclomeric P-ACA is not a polymerisable compound (a1). In addition, in the curable composition HC-R6 of Comparative Example 6, the content of a polymerizable compound with a molecular weight of 2000 or less in the total solid content of the curable composition is less than 70% by mass.

Compound III is an ultraviolet absorber with the following structure.

[Formula 25]

By infrared spectroscopy, in the cured product obtained by curing the curable compositions of Examples 1 to 8 under the above curing conditions, more than 80 mol% of the (meth)acrylic groups contained in the curable composition were groups other than (meth)acrylic groups. I confirmed that it had changed.

[Evaluation of hard coat film]

The hard coat films of each manufactured example and comparative example were evaluated by the following method. The evaluation results are shown in Table 2.

(Pencil hardness)

Pencil hardness was evaluated according to JIS (JIS is Japanese Industrial Standards) K5400. After controlling the humidity of the hard coat films of each Example and Comparative Example at a temperature of 25°C and a relative humidity of 60% for 2 hours, five different locations on the surface of the hard coat layer were subjected to H~ specified in JIS S 6006. It was scratched with a load of 4.9N using a 9H test pencil. After that, among the hardnesses of pencils in which 0 to 2 scratches were observed with the naked eye, the pencil hardness with the highest hardness was used as the evaluation result. As for pencil hardness, the higher the numerical value written in front of "H", the higher the hardness is and is preferable.

Pencil hardness was evaluated according to the following standards.

A: 5H or more, B: 4H or more but less than 5H, C: 3H or more but less than 4H, D: Less than 3H

(bending resistance)

Each sample was evaluated using the general test method for paints - bending resistance (cylindrical mandrel method) described in JIS-K-5600-5-1. After storing each sample for 1 hour at a temperature of 25°C and a relative humidity of 55%, the coated surface (hard coat layer) was applied to a mandrel with a diameter (Φ) of 2, 3, 4, 5, 6, 8, 10, 12, 14, and 16 mm. ) was wound on the outside (with the base material on the inside), the occurrence of cracks was observed, and the minimum mandrel diameter at which no cracks occurred was evaluated. The smaller the diameter (Φ) of the mandrel, the better the bending resistance, and as cracks occur under conditions of a larger diameter, the bending resistance is inferior. In addition, the presence or absence of cracks was judged visually.

The bending resistance was evaluated according to the following criteria.

A: 2mmΦ or less, B: 4mmΦ or less but greater than 2mmΦ, C: 8mmΦ or less but greater than 4mmΦ, D: Greater than 8mmΦ

(self-repairing)

Using a 4H test pencil specified in JIS S 6006, the surface of the hard coat layer was repeatedly scratched with a load of 4.9 N until 10 or more scratches were visually confirmed. After heating this sample at 85°C for 1 hour in a nitrogen atmosphere, scratches were observed and self-healing properties were evaluated based on the following criteria.

A: The scratch has disappeared (more than 90% recovered), B: The scratch has decreased to less than half (more than 50% and less than 90% recovered), C: The scratch has decreased, but not less than half (10% and more than 50%) less than 10% recovered), D: Scratches did not decrease (less than 10% recovered)

(transmittance)

The UV-Vis absorption spectrum was measured using UV-3100 (manufactured by Shimadzu Seisakusho), and it was confirmed that the transmittance of the hard coat films of all examples and comparative examples was 80% or more at any wavelength from 450 nm to 700 nm.

[Table 2]

The usage ratio of the polymerizable compounds in Examples 2 and 7 is mass ratio.

As shown in Table 2, the hard coat films of Examples 1 to 8 were excellent in pencil hardness, bending resistance, and self-healing property.

In addition, it was confirmed that no cracks occurred when a 180° bending test was repeated 10,000 times with a radius of curvature of 1.5 mm using the hard coat films of Examples 1 to 8 with the polyimide base material on the outside.

According to the present invention, a curable composition capable of forming a cured film that is excellent in pencil hardness and bending resistance and has self-healing properties, a hard coat film having a hard coat layer containing a cured product of the curable composition, and the hard coat. Articles equipped with coat films, image display devices, and flexible displays can be provided.

Although the present invention has been described in detail and with reference to specific embodiments, it is clear to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present invention.

This application is based on a Japanese patent application (Japanese patent application 2021-062146) filed on March 31, 2021, the contents of which are incorporated herein by reference.

Claims (18)

A curable composition containing a polymerizable compound having a molecular weight of 2000 or less,
The content of the polymerizable compound having a molecular weight of 2000 or less in the total solid content of the curable composition is 70% by mass or more,
Polymerizable, having one or more hydrogen-bonding groups and three or more (meth)acrylic groups in the molecule, a hydrogen-bonding proton value of 3.5 mol/kg or more, a (meth)acrylic value of 5.0 mol/kg or more, and a molecular weight of 2000 or less. A curable composition comprising compound (a1). In claim 1,
A curable composition wherein the sum of the hydrogen bondable proton value and the (meth)acrylic value of the polymerizable compound (a1) is 10.5 mol/kg or more. In claim 1 or claim 2,
The curable composition is cured under the following curing conditions, and has an elastic modulus of 9.5 GPa or more and an elongation at break of 10.0% or more as measured under the following measurement conditions.
Curing conditions: On a polyimide substrate with a thickness of 50 μm, the curable composition was applied to a bar so that the thickness after drying was 11 μm, then dried at 120 ° C. for 1 minute, at 80 ° C., illuminance 60 mW / cm ² , irradiation dose 600 mJ / cm. ² is cured with ultraviolet rays to form a cured product.
Measurement conditions: The laminate of the polyimide substrate and the cured product is measured with a maximum load of 50 mN using a micro hardness tester. The method according to any one of claims 1 to 3,
A curable composition wherein the content of the polymerizable compound (a1) in the total solid content of the curable composition is 51% by mass or more. In claim 3,
A curable composition wherein the cured product obtained by curing the curable composition under the curing conditions has a transmittance in the wavelength range of 400 to 700 nm of 80% or more at any wavelength. The method according to any one of claims 1 to 5,
A curable composition wherein the hydrogen bonding group is at least one selected from the group consisting of a urethane group, a thiourethane group, a urea group, a thiourea group, an amide group, and a thioamide group. The method according to any one of claims 1 to 6,
A curable composition wherein the polymerizable compound (a1) is a compound represented by the following general formula (1) or (2).
[Formula 1]

In general formula (1) ^, R represents a ^substituent , represents an atom or a methyl group, m represents an integer from 0 to 2, and n represents an integer from 2 to 4. However, when X represents C, the sum of m and n is 4, and when X represents N, the sum of m and n is 3. When m represents 2, the two R's may be the same or different. A plurality of L ¹ , A, L ² , and Q may each be the same or different.
[Formula 2]

In general formula (2), Z represents a k+w valent linking group, L ³ and L ⁴ each independently represent a single bond or a divalent linking group, A represents a hydrogen bonding group, and Q represents a hydrogen atom or a methyl group. , R represents a substituent, k represents an integer of 2 to 8, and w represents an integer of 0 to 2. A plurality of L ³ , A, L ⁴ , and Q may each be the same or different. When w represents 2, the two R's may be the same or different. The method according to any one of claims 1 to 7,
A curable composition further comprising at least one compound selected from the group consisting of fluorine-based compounds and silicone-based compounds. The method according to any one of claims 1 to 8,
A curable composition further comprising a solvent, wherein 80% by mass or more of the solvent is an organic solvent. In claim 3,
In the cured product obtained by curing the curable composition under the curing conditions, 80 mol% or more of the (meth)acrylic groups contained in the curable composition are changed to groups other than (meth)acrylic groups. In claim 3,
Using a laminate of the polyimide substrate and the cured product obtained by curing the curable composition under the curing conditions, the 180° bending test was repeated 10,000 times with the polyimide substrate facing outward at a radius of curvature of 1.5 mm. A curable composition that does not cause cracks. In claim 3,
When a bending resistance test was conducted using a laminate of the polyimide base material and the cured product obtained by curing the curable composition under the above curing conditions using the cylindrical mandrel method with the polyimide base material on the inside, a bending resistance test of 4 mm in diameter was performed. A curable composition that does not crack with a mandrel. A hard coat film having a base material and a hard coat layer containing a cured product of the curable composition according to any one of claims 1 to 12. In claim 13,
A hard coat film whose transmittance in the wavelength range of 450 to 700 nm is 80% or more at any wavelength. In claim 13 or claim 14,
A hard coat film wherein the substrate contains at least one polymer selected from the group consisting of polyimide, polyaramid, polyethylene terephthalate, polycarbonate, polyethylene naphthalate, polyurethane, acrylic resin, and cellulose resin. . An article provided with the hard coat film according to any one of claims 13 to 15. An image display device comprising the hard coat film according to any one of claims 13 to 15 as a surface protection film. A flexible display comprising the hard coat film according to any one of claims 13 to 15 as a surface protection film.