Coating film

Abstract

To provide a coating film with excellent flexibility and excellent fingerprint resistance. [Solution] A coated film comprising a substrate and a coating layer, wherein the substrate is a polyimide film, a polyamide film, a polyamide-imide film, a polyurethane film, or a flexible glass film, the flexible glass film is formed by laminating a primer layer on a glass film with a thickness of 10 to 200 μm, and the coating layer is formed by curing a curable composition containing a curable component and a plasticizer or porous fine particles, wherein the curable component contains a thermosetting component or an active energy ray curable component, the thermosetting component contains a urethane polymer, and the active energy ray curable component is a polyfunctional (meth)acrylate monomer or (meth)acrylate prepolymer with an acrylic equivalent of 90 to 300.

Description

[Technical Field]

[0001] This invention relates to a coating film suitable for use in flexible displays. [Background technology]

[0002] Liquid crystal displays (LCDs), organic light-emitting diodes (OLEDs), and touch panels are widely used in various electronic devices. To prevent scratches, the surfaces of these displays are often coated with a coating layer on a base film.

[0003] In recent years, flexible displays, or bendable displays, have been developed as a type of display as described above. Flexible displays are expected to have a wide range of applications, such as for stationary displays that can be curved and mounted on cylindrical pillars, or for mobile displays that can be folded or rolled up for portability. As for coating films for flexible displays, the coating films disclosed in Patent Documents 1 and 2 have been proposed. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2015-69197 [Patent Document 2] Patent No. 5468167 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] Incidentally, since touch panels are often operated with fingers, fingerprints from the oils of the fingers usually adhere to the surface of the touch panel. When fingerprints adhere to the surface of a touch panel in this way, it not only spoils the appearance but also makes the displayed image difficult to see. In recent years, there has been progress in constructing touch panels using flexible displays, and there is a need for a coating film that has both flexibility resistance, which does not cause problems even when repeatedly bent, and fingerprint resistance, which makes the attached fingerprints less noticeable. However, conventional coating films such as those in Patent Documents 1 and 2 have not been able to achieve a high level of both flexibility resistance and fingerprint resistance.

[0006] This invention has been made in view of the above circumstances, and aims to provide a coating film having excellent flexibility and excellent fingerprint resistance. [Means for solving the problem]

[0007] To achieve the above objective, firstly, the present invention provides a coated film comprising a substrate and a coating layer provided on at least one side of the substrate, wherein the substrate is at least one of a polyimide film, a polyamide film, a polyamide-imide film, a polyurethane film, and a flexible glass film, the flexible glass film is a glass film having a thickness of 10 μm or more and 200 μm or less with a primer layer laminated on at least one side, and the coating layer is obtained by curing a curable composition containing a curable component and at least one of a plasticizer and porous fine particles, wherein the curable component contains at least one of a thermosetting component and an active energy ray curable component, the thermosetting component contains a urethane polymer, and the active energy ray curable component is at least one of a polyfunctional (meth)acrylate monomer and a (meth)acrylate prepolymer, and is an acrylic component with an acrylic equivalent of 90 or more and 300 or less (Invention 1).

[0008] In the above invention (Invention 1), for the surface of the coating layer opposite to the substrate side, #0000 steel wool is used at a density of 125 g / cm³. 2 It is preferable that the number of scratches produced when rubbing 100 mm back and forth 10 times under a load is 20 or less (Invention 2).

[0009] In the above inventions (Inventions 1 and 2), it is preferable that the curable component contains a thermosetting component and the curable composition contains a crosslinking agent (Invention 3).

[0010] In the above inventions (Inventions 1 to 3), it is preferable that the curable component contains an active energy ray curable component, and the curable composition contains a photopolymerization initiator (Invention 4).

[0011] In the above inventions (Inventions 1 to 4), it is preferable that the invention be for optical purposes (Invention 5). [Effects of the Invention]

[0012] The coated film according to the present invention has excellent flexibility and excellent fingerprint resistance. [Modes for carrying out the invention]

[0013] Embodiments of the present invention will be described below. The coated film according to this embodiment comprises a substrate and a coating layer provided on at least one side of the substrate.

[0014] The above-mentioned substrate is at least one of a polyimide film, a polyurethane film, and a flexible glass film. Of these, the flexible glass film is a glass film having a thickness of 10 μm or more and 200 μm or less, with a primer layer laminated on at least one side.

[0015] Furthermore, the coating layer is formed by curing a curable composition containing a curable component and at least one of a plasticizer and porous fine particles. Among them, the curable component contains at least one of a thermosetting component and an active energy ray curable component. And the above thermosetting component contains a urethane polymer. On the other hand, the above active energy ray curable component is at least one of a polyfunctional (meth)acrylate monomer and a (meth)acrylate prepolymer, and is an acrylic component having an acrylic equivalent of 90 or more and 300 or less.

[0016] The coating film according to this embodiment has a base material that is at least one of the above three types of films, and the curable component that is the material of the coating layer satisfies the above conditions. When the coating film according to this embodiment is applied to a flexible display and repeatedly bent, the formation of bending marks and whitening are suppressed, and it has excellent bend resistance.

[0017] Furthermore, the coating film according to this embodiment has a coating layer formed by curing a curable composition containing at least one of a plasticizer and porous fine particles, so that the oil content of fingerprints to which the plasticizer and porous fine particles adhere is absorbed, and the visibility of fingerprints after a lapse of time is reduced.

[0018] As a result, the coating film according to this embodiment can achieve both excellent bend resistance and excellent fingerprint resistance at a high level. In particular, when a flexible display is configured using the coating film according to this embodiment, very high visibility can be realized in terms of both bend resistance and fingerprint resistance.

[0019] 1. Base material The base material in this embodiment is, as described above, at least one of a polyimide film, a polyamide film, a polyamideimide film, a polyurethane film, and a flexible glass film.

[0020] (1) Polyimide film As the polyimide film, it is preferable to use a transparent and less yellowish polyimide film. By doing so, a display (especially a flexible display) that displays clear and highly color - reproducible images can be obtained.

[0021] The polyimide film in this specification refers to a film containing polyimide, that is, a polymer having an imide bond in the main chain, preferably 50% by mass or more, particularly preferably 80% by mass or more, and more preferably 90% by mass or more. Note that poly(meth)acrylimide is not a polyimide because it does not have an imide bond in the main chain, and when such a poly(meth)acrylimide film is repeatedly bent, it will turn white.

[0022] The polyimide film can usually be obtained by polymerizing a tetracarboxylic dianhydride (preferably an aromatic tetracarboxylic dianhydride) and a diamine (preferably an aromatic diamine) in a solution to form a polyamic acid, then forming the polyamic acid into a film shape, and then dehydrating and closing the ring of the polyamic acid moiety, but it is not limited to this.

[0023] The polyimide in the polyimide film may be modified. For example, the aromatic rings usually contained in the polyimide may be modified to aliphatic hydrocarbons, whereby the base film 2 has excellent adhesion to the hard - coat layer 4.

[0024] In the above - mentioned polyimide film, for the purpose of improving the adhesion to the layer provided on its surface (such as a coat layer and an adhesive layer described later), if desired, surface treatment can be performed on one or both sides by primer treatment, oxidation method, roughening method, etc. Examples of the oxidation method include corona discharge treatment, chromic acid treatment, flame treatment, hot - air treatment, ozone - ultraviolet treatment, etc., and examples of the roughening method include sand - blasting method, solvent treatment method, etc.

[0025] The thickness of the polyimide film is preferably 5 μm or more, particularly preferably 7.5 μm or more, and even more preferably 10 μm or more. This allows the coated film to exhibit a predetermined mechanical strength and to be resistant to breakage even when repeatedly bent. On the other hand, the thickness of the polyimide film is preferably 300 μm or less, particularly preferably 90 μm or less, and even more preferably 50 μm or less. Since polyimide films are easily colored, transparency is ensured when the thickness of the polyimide film is below the above limits, making it suitable for optical applications. Furthermore, when the thickness of the polyimide film is below the above limits, the coated film exhibits a predetermined flexibility and is easy to bend.

[0026] (2) Polyamide film The polyamide film in this embodiment is not particularly limited, and a general type can be used.

[0027] In the above-mentioned polyamide film, surface treatment can be applied to one or both sides, if desired, by priming, oxidation, or embossing, in order to improve adhesion with layers provided on its surface (such as a coating layer or an adhesive layer described later). Examples of oxidation methods include corona discharge treatment, chromic acid treatment, flame treatment, hot air treatment, and ozone / ultraviolet treatment, while examples of embossing methods include sandblasting and solvent treatment.

[0028] The thickness of the polyamide film is preferably 5 μm or more, particularly preferably 7.5 μm or more, and even more preferably 10 μm or more. This allows the coated film to exhibit a predetermined mechanical strength and to be resistant to breakage even when repeatedly bent. On the other hand, the thickness of the polyamide film is preferably 300 μm or less, particularly preferably 90 μm or less, and even more preferably 50 μm or less. When the thickness of the polyamide film is less than or equal to the above, the coated film exhibits a predetermined flexibility and is easy to bend.

[0029] (3) Polyamide-imide film The polyamide-imide film in this embodiment is not particularly limited, and a general type can be used.

[0030] In the above-mentioned polyamide-imide film, surface treatment can be applied to one or both sides, if desired, by priming, oxidation, or embossing, in order to improve adhesion with layers provided on its surface (such as a coating layer or an adhesive layer described later). Examples of oxidation methods include corona discharge treatment, chromic acid treatment, flame treatment, hot air treatment, and ozone / ultraviolet treatment, while examples of embossing methods include sandblasting and solvent treatment.

[0031] The thickness of the polyamide-imide film is preferably 5 μm or more, particularly preferably 7.5 μm or more, and even more preferably 10 μm or more. This allows the coated film to exhibit a predetermined mechanical strength and to be resistant to breakage even when repeatedly bent. On the other hand, the thickness of the polyamide-imide film is preferably 300 μm or less, particularly preferably 90 μm or less, and even more preferably 50 μm or less. When the thickness of the polyamide-imide film is less than or equal to the above, the coated film exhibits a predetermined flexibility and is easy to bend.

[0032] (4) Polyurethane film The polyurethane film described above is not particularly limited, but it is preferable to use a polyurethane obtained by reacting a polyol compound with a polyisocyanate compound as the material.

[0033] Examples of the polyol compounds mentioned above include polyester polyols, polyether polyols, polyether ester polyols, polyester amide polyols, acrylic polyols, polycarbonate polyols, polyhydroxyalkanes, castor oil, and polyurethane polyols. These can be used individually or in combination of two or more.

[0034] Examples of the polyisocyanate compounds mentioned above include aliphatic diisocyanates, alicyclic diisocyanates, aromatic diisocyanates, aromatic aliphatic diisocyanates, and triisocyanates. These can be used individually or in combination of two or more.

[0035] The thickness of the polyurethane film is preferably 5 μm or more, particularly preferably 7.5 μm or more, and even more preferably 10 μm or more. This allows the coated film to exhibit a predetermined mechanical strength and to be resistant to breakage even when repeatedly bent. On the other hand, the thickness of the polyurethane film is preferably 300 μm or less, particularly preferably 90 μm or less, and even more preferably 50 μm or less. This allows the coated film to exhibit a predetermined flexibility and to be easily bent.

[0036] (5) Flexible glass film As described above, the flexible glass film is made by laminating a primer layer on at least one side of a glass film having a thickness of 10 μm or more and 200 μm or less.

[0037] While the glass constituting the above-mentioned glass film is not particularly limited, chemically strengthened glass is preferable from the viewpoint of excellent flexibility and impact resistance. Furthermore, chemically strengthened glass is also preferable because it has excellent mechanical strength, which makes it easier to adjust to the aforementioned thickness.

[0038] Examples of glass materials that make up the above-mentioned chemically strengthened glass include aluminosilicate glass, soda-lime glass, borosilicate glass, lead glass, alkali barium glass, and aluminoborsilicate glass.

[0039] As mentioned above, the thickness of the glass film is 10 μm or more and 200 μm or less, but from the viewpoint of further improving bending resistance and impact resistance, it is preferable to have a thickness of 15 μm or more and 150 μm or less, and particularly preferable to have a thickness of 25 μm or more and 100 μm or less.

[0040] The primer layer is not particularly limited as long as it improves the adhesion between the glass film and the coating layer laminated thereon, but it is preferable that it is composed of a silane coupling agent, for example.

[0041] As a silane coupling agent, an organosilicon compound having at least one alkoxysilyl group in its molecule and possessing light-permeability is preferred.

[0042] Examples of such silane coupling agents include polymerizable unsaturated group-containing silicon compounds such as vinyltrimethoxysilane, vinyltriethoxysilane, and methacryloxypropyltrimethoxysilane; silicon compounds having an epoxy structure such as 3-glycidoxypropyltrimethoxysilane and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; and mercapto group-containing silicon compounds such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, and 3-mercaptopropyldimethoxymethylsilane. Examples include amino group-containing silicon compounds such as 3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, and N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane; 3-chloropropyltrimethoxysilane; 3-isocyanatetopropyltriethoxysilane; or condensates of at least one of these with alkyl group-containing silicon compounds such as methyltriethoxysilane, ethyltriethoxysilane, methyltrimethoxysilane, and ethyltrimethoxysilane. These may be used individually or in combination of two or more.

[0043] The silane coupling agent described above can be applied to one side of a glass film by a conventional method and cured to form a primer layer. Curing is preferably carried out by heating, for example, at a temperature of 50 to 150°C for 0.5 minutes to 1 hour.

[0044] 2. Coat layer As described above, the coating layer in this embodiment is obtained by curing a curable composition containing a curable component and at least one of a plasticizer and porous fine particles. The other components of the curable composition are not particularly limited, but it is preferable to include fine particles, a photopolymerization initiator, etc., as needed.

[0045] (1) Curable component As described above, the curable component in this embodiment contains at least one of a thermosetting component and an active energy ray curable component.

[0046] Furthermore, the thermosetting component contains a urethane polymer, and the active energy ray curable component is an acrylic component which is at least one of a polyfunctional (meth)acrylate monomer and a (meth)acrylate prepolymer, with an acrylic equivalent of 90 or more and 300 or less.

[0047] Urethane polymers used as thermosetting components are obtained by reacting polyol compounds with polyisocyanate compounds. Examples of polyol compounds include polyester polyols, polyether polyols, polyether ester polyols, polyesteramide polyols, acrylic polyols, polycarbonate polyols, polyhydroxyalkanes, and polyurethane polyols. These can be used individually or in combination of two or more.

[0048] Examples of polyisocyanate compounds include aliphatic diisocyanates, alicyclic diisocyanates, aromatic diisocyanates, aromatic aliphatic diisocyanates, and triisocyanates. These can be used individually or in combination of two or more.

[0049] The urethane polymer may have reactive functional groups that react with the crosslinking agent described later. Examples of such reactive functional groups include hydroxyl groups, carboxyl groups, and amino groups. Among these, hydroxyl groups are preferred because they are easily retained during the manufacturing process of the urethane polymer.

[0050] The weight-average molecular weight of the urethane polymer is preferably 1,000 to 300,000, more preferably 5,000 to 200,000, particularly preferably 10,000 to 100,000, and even more preferably 20,000 to 60,000.

[0051] In this embodiment, the urethane polymer is a concept that also includes urethane acrylate prepolymers. Urethane acrylate prepolymers can be obtained, for example, by esterifying polyurethane oligomers obtained by the reaction of polyether polyols or polyester polyols with polyisocyanates with (meth)acrylic acid.

[0052] Examples of polyfunctional (meth)acrylate monomers used as active energy ray curing components include 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, hydroxypivalate neopentyl glycol di(meth)acrylate, dicyclopentanyl di(meth)acrylate, caprolactone-modified dicyclopentenyl di(meth)acrylate, ethylene oxide-modified phosphate di(meth)acrylate, allylated cyclohexyl di(meth)acrylate, isocyanurate di(meth)acrylate, and trimethylolpropane. Examples of polyfunctional (meth)acrylates include tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, propionic acid-modified dipentaerythritol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, propylene oxide-modified trimethylolpropane tri(meth)acrylate, tris(acryloxyethyl) isocyanurate, propionic acid-modified dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, ethylene oxide-modified dipentaerythritol hexa(meth)acrylate, and caprolactone-modified dipentaerythritol hexa(meth)acrylate. These may be used individually or in combination of two or more.

[0053] Examples of (meth)acrylate-based prepolymers used as active energy ray curing components include polyester acrylate-based, epoxy acrylate-based, and polyol acrylate-based prepolymers.

[0054] Polyester acrylate prepolymers can be obtained, for example, by esterifying the hydroxyl groups of a polyester oligomer having hydroxyl groups at both ends, obtained by condensation of a polycarboxylic acid and a polyhydric alcohol, with (meth)acrylic acid, or by esterifying the terminal hydroxyl groups of an oligomer obtained by adding an alkylene oxide to a polycarboxylic acid with (meth)acrylic acid.

[0055] Epoxyacrylate prepolymers can be obtained, for example, by reacting (meth)acrylic acid with the oxirane ring of a relatively low molecular weight bisphenol-type epoxy resin or novolac-type epoxy resin to esterify it.

[0056] Polyol acrylate-based prepolymers can be obtained, for example, by esterifying the hydroxyl groups of a polyether polyol with (meth)acrylic acid.

[0057] The (meth)acrylate-based prepolymer may have reactive functional groups that react with the crosslinking agent described later. Examples of such reactive functional groups include hydroxyl groups, carboxyl groups, and amino groups.

[0058] The weight-average molecular weight of the (meth)acrylate-based prepolymer is preferably 1,000 to 60,000, particularly preferably 3,000 to 40,000, and even more preferably 5,000 to 30,000. In this specification, the weight-average molecular weight is the value on a standard polystyrene basis, measured by gel permeation chromatography (GPC).

[0059] As mentioned above, the acrylic equivalent of the acrylic component related to the active energy ray curable component is 90 or more and 300 or less, but from the viewpoint of easily achieving better flexural resistance, it is preferable to be 100 to 300, and particularly preferable to be 120 to 300.

[0060] (2) Plasticizers Plasticizers are typically used to soften resins, but in this embodiment, by being present in the coating layer, they can absorb sebum adhering to the surface of the coating layer.

[0061] Examples of plasticizers include citrate-based plasticizers such as tributyl acetylcitrate and triethyl acetylcitrate; phthalate ester plasticizers such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dioctyl phthalate, di-n-octyl phthalate, and dicyclohexyl phthalate; trimellitic acid ester plasticizers such as trioctyl trimellitic acid, triisononyl trimellitic acid, and triisodecyl trimellitic acid; and dioctyl adipate, diisononyl adipate, and diisodecyl adipate. Examples include adipic acid-based plasticizers such as phosphate; polyester-based plasticizers such as phthalic acid-based polyesters; phosphate ester-based plasticizers such as tricresyl phosphate, trioctyl phosphate, and triphenyl phosphate; epoxy-based plasticizers such as epoxidized linseed oil and epoxidized butyl stearate; liquid polybutene, mineral oil, lanolin, wax, liquid polyisoprene, liquid polyacrylate, triethanolamine, alkylamine, amine alkylene oxide adducts, glycerin, diglycerin, and silicone oil. These may be used individually or in combination of two or more.

[0062] Among the above, citric acid-based plasticizers are preferred, and tributyl acetylcitrate is particularly preferred, from the viewpoint of easily exhibiting good sebum absorption while maintaining scratch resistance.

[0063] The content of the plasticizer in the curable composition of this embodiment is preferably 0.1 to 100 parts by mass, more preferably 1.0 to 75 parts by mass, particularly preferably 3.0 to 50 parts by mass, even more preferably 6.0 to 25 parts by mass, and most preferably 9.0 to 15 parts by mass, per 100 parts by mass of the curable component. This allows the sebum-absorbing properties to be effectively exhibited.

[0064] (3) Porous fine particles The curable composition in this embodiment contains porous fine particles, which allows it to absorb sebum adhering to the surface of the coating layer.

[0065] As porous microparticles, examples of pore structures include micropores with a diameter of 2 nm or less, mesopores with a diameter of 2 to 50 nm, and macropores with a diameter of 50 to 100 nm. Depending on the properties of the porous material used, a structure exhibiting the desired sebum absorption can be appropriately selected. This pore structure can be confirmed, for example, by observing the surface of the microparticles using an electron microscope.

[0066] Examples of porous microparticles with sebum-absorbing properties include microparticles made from porous materials such as activated carbon, silica gel, zeolite, porous coordination polymer (PCP), covalent organic framework (COF), and metal organic framework (MOF). These may be used individually or in combination of two or more types.

[0067] The porous microparticles may be either regular or irregular in shape. From the viewpoint of easily exhibiting sebum absorption properties, a regular shape is preferred, a spherical shape is particularly preferred, and a perfectly spherical shape is even more preferred. Furthermore, from the viewpoint of easily providing anti-glare properties while exhibiting sebum absorption properties, an irregular shape is preferred.

[0068] The average particle size of the porous microparticles is preferably 0.01 to 20 μm, particularly preferably 0.1 to 15 μm, and even more preferably 1 to 10 μm. This results in good sebum absorption.

[0069] The specific surface area of ​​porous microparticles is 100 to 10,000 m². 2 It is preferable that the value be / g, and especially 500-8000m 2 It is preferable that the amount be / g. This will result in excellent sebum absorption.

[0070] The pore volume of the porous microparticles is preferably 0.01 to 10 ml / g, and particularly preferably 0.1 to 5 ml / g. This results in excellent sebum absorption.

[0071] The content of porous fine particles in the curable composition of this embodiment is preferably 1 to 100 parts by mass, and particularly preferably 10 to 90 parts by mass, per 100 parts by mass of the curable component. This allows for effective sebum absorption.

[0072] (4) Photopolymerization initiator When using an active energy ray-curable component as the curable component, it is also preferable for the curable composition to contain a photopolymerization initiator. This allows for efficient polymerization of the curable component and reduces the polymerization curing time and the amount of active energy ray irradiation.

[0073] Examples of photopolymerization initiators include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, α-hydroxyphenyl ketone, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2-propyl)ketone, benzophenone, p-phenylbenzophenone Examples include non, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyldimethyl ketal, acetophenone dimethyl ketal, p-dimethylaminobenzoic acid ester, oligo[2-hydroxy-2-methyl-1[4-(1-methylvinyl)phenyl]propanone], 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, etc. These may be used individually or in combination of two or more.

[0074] The amount of photopolymerization initiator in the curable composition is preferably 0.01 to 20 parts by mass, particularly preferably 0.1 to 15 parts by mass, and even more preferably 1 to 10 parts by mass, per 100 parts by mass of the curable component.

[0075] (5) Crosslinking agents The curable composition in this embodiment may also preferably contain a crosslinking agent. In particular, when a curable component having a reactive functional group is used as the curable component, including a crosslinking agent makes it easier to crosslink the curable component and form a coating layer with the desired strength.

[0076] The crosslinking agent can be any agent that reacts with the curable component to crosslink the curable component. Examples of crosslinking agents include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, amine-based crosslinking agents, melamine-based crosslinking agents, aziridine-based crosslinking agents, hydrazine-based crosslinking agents, aldehyde-based crosslinking agents, oxazoline-based crosslinking agents, metal alkoxide-based crosslinking agents, metal chelate-based crosslinking agents, metal salt-based crosslinking agents, and ammonium salt-based crosslinking agents.

[0077] When the curing component is a urethane polymer (particularly a urethane polymer having hydroxyl groups), it is preferable to use an isocyanate-based crosslinking agent that readily crosslinks the urethane polymer. The crosslinking agent can be used individually or in combination of two or more types.

[0078] The isocyanate-based crosslinking agent contains at least a polyisocyanate compound. Examples of polyisocyanate compounds include aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, and xylylene diisocyanate; aliphatic polyisocyanates such as hexamethylene diisocyanate; alicyclic polyisocyanates such as isophorone diisocyanate and hydrogenated diphenylmethane diisocyanate; and their biuret forms, isocyanurate forms, and adduct forms which are reaction products with low molecular weight active hydrogen-containing compounds such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, and castor oil. Among these, isocyanurate forms of aliphatic polyisocyanates are preferred from the viewpoint of easily maintaining sebum absorption by plasticizers or porous fine particles.

[0079] In this embodiment, the amount of crosslinking agent in the curable composition is preferably 1 to 100 parts by mass, more preferably 5 to 75 parts by mass, particularly preferably 10 to 50 parts by mass, and even more preferably 15 to 25 parts by mass, per 100 parts by mass of the curable component.

[0080] (6) Other ingredients The curable composition according to this embodiment may contain various additives in addition to the components described above. Examples of such additives include fillers, leveling agents, dispersants, antifouling agents, ultraviolet absorbers, infrared absorbers, antioxidants, light stabilizers, antistatic agents, silane coupling agents, anti-aging agents, thermal polymerization inhibitors, colorants, surfactants, preservative stabilizers, lubricants, and defoamers.

[0081] (7) Preparation of curable compositions The curable composition in this embodiment can be prepared by mixing a curable component, a plasticizer, and at least one porous fine particle, and optionally a crosslinking agent, a photopolymerization initiator, an additive, etc., preferably in a solvent.

[0082] To form a coating layer of the curable composition, it is preferable to apply the coating liquid of the curable composition to the desired surface of the substrate and allow it to dry. The coating liquid of the curable composition may be the curable composition itself, or it may optionally contain a solvent. The solvent can be used to improve coating properties, adjust viscosity, adjust solid content concentration, etc., and is not particularly limited as long as it dissolves or disperses each component. Specific examples of solvents include alcohols such as methanol, ethanol, isopropanol, butanol, and octanol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; esters such as ethyl acetate, butyl acetate, ethyl lactate, and γ-butyrolactone; ethers such as ethylene glycol monomethyl ether (methyl cellosolub), ethylene glycol monoethyl ether (ethyl cellosolub), diethylene glycol monobutyl ether (butyl cellosolub), and propylene glycol monomethyl ether; aromatic hydrocarbons such as benzene, toluene, and xylene; and amides such as dimethylformamide, dimethylacetamide, and N-methylpyrrolidone.

[0083] The concentration and viscosity of the coating solution of the curable composition are not particularly limited, as long as they are within the range of coating, and can be appropriately selected depending on the situation. For example, the curable composition may be diluted to a concentration of 10 to 60% by mass.

[0084] (8) Thickness of the coating layer In this embodiment, the thickness of the coating layer is preferably 0.5 to 50 μm, more preferably 1 to 30 μm, particularly preferably 2 to 20 μm, even more preferably 3 to 15 μm, and most preferably 4 to 12 μm. This allows for the effective expression of excellent sebum absorption.

[0085] 3. Other components The coated film according to this embodiment may have an adhesive layer on the side of the substrate opposite to the coated layer. The adhesive constituting the adhesive layer is not particularly limited, and known adhesives such as acrylic adhesives, rubber adhesives, silicone adhesives, and urethane adhesives can be used, and it is preferable to use an adhesive having a predetermined transparency.

[0086] Furthermore, if the coated film according to this embodiment includes the adhesive layer described above, a release film may be laminated on the side of the adhesive layer opposite to the substrate. The release film is not particularly limited as long as it has the desired release properties on its release surface (the surface in contact with the adhesive layer), and known release films such as resin films in which one side has been treated with a release agent can be used.

[0087] 4. Method for manufacturing coated film The method for manufacturing the coated film according to this embodiment is not particularly limited and can be manufactured by conventional methods. For example, the coated film according to this embodiment can be obtained by applying the curable composition (coating liquid) prepared as described above to one side of a substrate, and then drying and curing the resulting coating layer.

[0088] The curable composition (or its coating solution) can be applied by conventional methods, such as bar coating, knife coating, roll coating, blade coating, die coating, or gravure coating.

[0089] When forming a coating layer by heat curing, it is preferable to perform a heat treatment that serves both to dry and cure the coating layer, followed by curing. The temperature of the heat treatment is preferably 50 to 150°C, more preferably 70 to 130°C, and the duration is preferably 0.5 to 3 minutes, more preferably 1 to 2 minutes. The temperature of the subsequent curing is preferably 15 to 100°C, more preferably 18 to 60°C, even more preferably 22 to 40°C, and the duration is preferably 1 to 14 days, more preferably 2 to 10 days, and even more preferably 3 to 7 days.

[0090] On the other hand, when forming a coating layer by active energy ray curing, the heating temperature for drying the coating layer is preferably 50 to 150°C, particularly preferably 50 to 150°C, particularly preferably 70 to 130°C, and the heating time is preferably 0.2 to 2 minutes, particularly preferably 0.5 to 1 minute.

[0091] Examples of active energy rays used for curing include ultraviolet light and electron beams. Ultraviolet irradiation can be performed using high-pressure mercury lamps, Heraeus H lamps, xenon lamps, etc., and the irradiation dose of ultraviolet light should be 50 to 1000 mW / cm². 2 , light intensity 50~1000mJ / cm 2 A certain degree is preferable. On the other hand, electron beam irradiation can be performed using an electron beam accelerator, and the electron beam irradiation dose is preferably around 10 to 1000 krad.

[0092] 5. Physical properties of the coating film In the coated film according to this embodiment, 125 g / cm³ of #0000 steel wool is used on the surface of the coated layer opposite to the substrate. 2When rubbed 100 mm back and forth 10 times under a load, the number of scratches produced is preferably 20 or less, particularly preferably 5 or less, and even more preferably 0. This makes it easier for the coated film according to this embodiment to have excellent scratch resistance. Details of the method for measuring the number of scratches are described in the test examples below.

[0093] 6. How to use the coating film The coated film according to this embodiment can be used without particular limitations in applications where fingerprint resistance and flexibility are required, and is particularly suitable for optical applications. The coated film according to this embodiment can be preferably used, for example, as a flexible component of the surface layer (protective film) or intermediate layer of various flexible displays in various electronic devices, particularly mobile electronic devices, specifically liquid crystal displays (LCDs), organic light-emitting diodes (OLEDs), electronic paper modules (film-type electronic paper), etc. Lamination of the coated film to other parts is preferably performed by attaching it via the adhesive layer described above.

[0094] The embodiments described above are provided to facilitate understanding of the present invention and are not intended to limit it. Accordingly, each element disclosed in the above embodiments is intended to include all design modifications and equivalents that fall within the technical scope of the present invention. [Examples]

[0095] The present invention will be described in more detail below with reference to examples, but the scope of the present invention is not limited to these examples.

[0096] [Example 1] 100 parts by mass (solid content equivalent; the same applies hereafter) of a thermosetting component, a urethane acrylate prepolymer (manufactured by Tokushiki Co., Ltd., product name "AU-2513* solid content concentration 40%", weight-average molecular weight: 32000, containing a silicone-based leveling agent), 10 parts by mass of tributyl acetyl citrate as a plasticizer, and 18 parts by mass of a hexamethylene diisocyanate nurate (manufactured by Tokushiki Co., Ltd., product name "UAX-700", weight-average molecular weight: 240-2400) as a crosslinking agent were mixed using propylene glycol monomethyl ether as a diluent to obtain a coating solution of a curable composition with a solid content concentration of 40% by mass.

[0097] A polyamic acid solution was obtained by mixing and dissolving 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, biphenyltetracarboxylic acid dianhydride, and 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropanoic acid dianhydride in N,N-dimethylacetamide solvent under cooling conditions, and then stirring at room temperature for 10 hours.

[0098] Acetic anhydride and pyridine were added to the obtained polyamic acid solution, and after thorough stirring, the solution was coated onto a glass plate and slowly heated from room temperature to 180°C. After reaching 180°C, it was heated for a certain period of time, and then volatile components were completely removed by vacuum evacuation. Finally, a polyimide film (thickness 25 μm) as a substrate was obtained by cooling to room temperature under vacuum. Measurements of the polyimide film showed a b* of 0.61, a refractive index of 1.62, and a transmittance of 90% at a wavelength of 550 nm.

[0099] The coating solution prepared as described above was applied to one side of the substrate obtained as described above using a wire bar. The resulting coating film was dried at 120°C for 1 minute. Furthermore, it was cured at room temperature for 3 days. As a result, the coating film hardened and became a coating layer. Thus, a coated film consisting of the substrate and the coating layer was obtained. The thickness of the coating layer was measured to be 10 μm.

[0100] [Example 2, Example 3, Comparative Example 1, Comparative Example 4] A coated film was obtained in the same manner as in Example 1, except that the composition of the curable composition and the substrate used were changed as shown in Table 1. Details of each component in Table 1 are shown in Table 2.

[0101] In particular, for the glass film used as the substrate, a 70 μm thick glass film made by heat-treating soda-lime glass to create tempered glass was prepared and used. For the primer layer, a coating solution obtained by diluting a silane coupling agent (Shin-Etsu Chemical Co., Ltd., product name "X-12-1159L") with methyl ethyl ketone to a solid content concentration of 0.5 wt% was applied to one side of the glass film using a wire bar #4, and then dried and cured at 120°C for 5 minutes to form the primer layer.

[0102] [Example 4] 100 parts by mass of dipentaerythritol hexaacrylate (acrylic equivalent: 96), an active energy ray curable component, 75 parts by mass of nanosilica fine particles (average particle size 10 nm) as inorganic fine particles, 10 parts by mass of tributyl acetyl citrate as a plasticizer, and 3 parts by mass of 1-hydroxycyclohexyl phenyl ketone (manufactured by IGM Resin, product name "OMINIRAD 184") as a photopolymerization initiator were mixed using propylene glycol monomethyl ether as a diluent to obtain a coating solution of a curable composition with a solid content concentration of 30% by mass.

[0103] The above coating solution was applied to one side of a polyimide film, prepared in the same manner as in Example 1, using a wire bar. The resulting coating film was dried at 70°C for 1 minute. Subsequently, the coating film was cured by ultraviolet irradiation under the following conditions to form a coating layer. This resulted in a coated film consisting of a substrate and a coating layer. The thickness of the coating layer was measured to be 5 μm. [Ultraviolet irradiation conditions] • UV irradiation device: Manufactured by GS Yuasa Corporation, UV irradiation device • Light source: High-pressure mercury lamp Lamp power: 1.4kW ·Illuminance: 100mW / cm 2 · Light quantity: 240 mJ / cm 2 · Conveyor speed: 1.2 m / min · Ultraviolet irradiation in a nitrogen atmosphere (oxygen concentration 1% or less)

[0104] 〔Example 5, Example 6, Comparative Example 2, Comparative Example 3〕 A coated film was obtained in the same manner as in Example 4, except that the composition of the curable composition, the substrate to be used, and the thickness of the coat layer were changed as shown in Table 1.

[0105] 〔Test Example 1〕(Evaluation of fingerprint resistance) The surface on the substrate side of the coated films prepared in the examples and comparative examples was adhered to one side of a black acrylic plate (manufactured by Mitsubishi Rayon Co., Ltd., product name "Acrylite L502") using an acrylic-based transparent adhesive (refractive index: 1.49, haze: <1.0%).

[0106] Then, fingerprints were attached to the surface on the coat layer side, and at the time point 24 hours later, the fingerprints were visually evaluated under a fluorescent lamp. The fingerprint resistance was evaluated based on the following criteria. The results are shown in Table 3. 3 points: Fingerprints are hardly visible. 2 points: Fingerprints are visible. 1 point: Fingerprints are clearly visible.

[0107] 〔Test Example 2〕(Evaluation of scratch resistance) Regarding the coated films prepared in the examples and comparative examples, the surface on the coat layer side of the coated film was rubbed 10 times back and forth with #0000 steel wool under a load of 125 g / cm 2 The number of scratches in the test range, which was set to a range of 100 mm in length × 20 mm in width (reciprocated in the length direction), was counted visually under a three-wavelength fluorescent lamp, and the scratch resistance was evaluated based on the following criteria. The results are shown in Table 3. Note that two or more points are judged to be good. 3 points: The number of scratches was 5 or less. 2 points: The number of scratches was more than 5 and 20 or less. 1 point: The number of scratches was more than 20.

[0108] [Test Example 3] (Evaluation of Adhesion) In the coated films produced in the examples and comparative examples, the coated layer was cross-cut in a grid pattern with a cut interval of 5 mm and 10 x 10 cut lines, creating a cross-cut area with 100 squares. Then, adhesive tape (manufactured by Nichiban Co., Ltd., product name "Sellotape®") was applied to the coated layer so as to cover the cross-cut area, and a peel test was performed in accordance with the grid tape method of JIS K5600-5-6:1999 (cross-cut method).

[0109] We counted the number of squares that had peeled (including those where only the edges of the cuts had peeled) out of 100 squares. The results are shown in Table 3.

[0110] [Test Example 4] (Evaluation of repeated bending resistance) The coated films produced in the examples and comparative examples were subjected to repeated bending using a durability tester (Yuasa System Equipment Co., Ltd., product name "Planar Material Unloaded U-Shaped Expansion Tester DLDMLH-FS") with the coated layer facing outwards, at a test speed of 60 mm / s, varying the number of test cycles (reciprocating motions) and bending diameter. The presence or absence of defects such as cracks and peeling of the coating layer, and whitening, bending marks, and breakage of the film was checked, and the bending resistance was evaluated according to the following criteria. The results are shown in Table 3. A score of 2 or higher is considered good. 3. No defects occurred even with a bending diameter of 5 mm or less and more than 20,000 test cycles. Two points: No defects occurred even with a bending diameter of 10 mm or less and more than 20,000 test cycles. The score fell short of the 1-point:2-point standard.

[0111] [Table 1]

[0112] [Table 2]

[0113] [Table 3]

[0114] As can be seen from Table 3, the coated films obtained in the examples exhibited excellent resistance to both fingerprints and bending. Furthermore, the coated films obtained in the examples also showed sufficient scratch resistance. [Industrial applicability]

[0115] The coating film of the present invention is suitable as a protective film located on the surface of a flexible component constituting a flexible display that is repeatedly bent.

Claims

1. A coated film comprising a base material and a coating layer provided on at least one side of the base material, The substrate is at least one of a polyimide film, polyamide film, polyamide-imide film, polyurethane film, and flexible glass film. The flexible glass film is formed by laminating a primer layer on at least one side of a glass film having a thickness of 10 μm or more and 200 μm or less. The coating layer is obtained by curing a curable composition containing a curable component, a plasticizer, and at least one of porous fine particles. The curable component contains at least one of a thermosetting component and an active energy ray curable component. The aforementioned thermosetting component contains a urethane polymer, The active energy ray curable component is an acrylic component which is at least one of a polyfunctional (meth)acrylate monomer and a (meth)acrylate prepolymer, and has an acrylic equivalent of 90 or more and 300 or less. A coating film characterized by the following features.

2. On the surface of the coating layer opposite to the substrate side, 125 g / cm³ of #0000 steel wool was used. ２ The coating film according to claim 1, characterized in that the number of scratches produced when rubbed 100 mm back and forth 10 times under a load is 20 or less.

3. The aforementioned curable component contains a thermosetting component, The curable composition contains a crosslinking agent. The coated film according to feature 1.

4. The curable component contains an active energy ray curable component, The curable composition contains a photopolymerization initiator. The coated film according to feature 1.

5. The coating film according to claim 1, characterized in that it is for optical use.

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