Coating film

Abstract

The present invention provides a coating film that can suppress the visibility of fingerprints not only immediately after they are applied, but also after a period of time has passed. [Solution] A coated film comprising a substrate and a coating layer provided on at least one side of the substrate, wherein the coating layer is formed by curing a curable composition containing a curable component, a plasticizer, and at least one porous fine particles, the haze value of the coated film is 2.0% or more and 95.0% or less, and the reflectance of the surface of the coating layer opposite to the substrate is 1.0% or more and 7.0% or less.

Description

[Technical Field]

[0001] This invention relates to a coating film having fingerprint resistance. [Background technology]

[0002] In recent years, touch panels, which serve as both display and input devices, have become widely used in various electronic devices. Because these touch panels are often operated with fingers, fingerprints from the skin's oils typically accumulate on their surface. This accumulation of fingerprints not only detracts from the appearance of the touch panel but also makes the displayed image difficult to see.

[0003] Therefore, Patent Document 1 proposes a coating film for lamination on the surface of a touch panel or the like, comprising a layer containing a fluorine-containing compound and having a predetermined surface roughness. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2017-13510 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, with conventional coating films such as those described in Patent Document 1, while it is possible to suppress the visibility of fingerprints to a certain extent immediately after they are applied, the fingerprints remain on the film surface even after time has passed. Therefore, when fingerprints are applied again, they accumulate, and the fingerprint resistance decreases.

[0006] This invention has been made in view of the above circumstances, and aims to provide a coating film that can suppress the visibility of fingerprints not only immediately after they are applied, but also after a period of time has passed. [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 coating layer is obtained by curing a curable composition containing a curable component, a plasticizer, and porous fine particles, the haze value of the coated film is 2.0% or more and 95.0% or less, and the reflectance of the surface of the coating layer opposite to the substrate is 1.0% or more and 7.0% or less (Invention 1).

[0008] In the above invention (Invention 1), it is preferable that the arithmetic mean surface roughness Ra of the surface of the coating layer opposite to the substrate is 0.03 μm or more and 1.5 μm or less (Invention 2).

[0009] In the above invention (Inventions 1 and 2), for the surface of the coating layer opposite to the substrate, 125 g / cm³ of #0000 steel wool is used. 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 3).

[0010] In the above inventions (Inventions 1 to 3), it is preferable that the curable composition contains fine particles other than the porous fine particles (Invention 4).

[0011] In the above inventions (Inventions 1 to 4), it is preferable that the coating layer is formed by applying the curable composition to the substrate to form a coating layer, and then curing the coating layer with the uneven surface of a laminated substrate having an uneven surface laminated on the side of the coating layer opposite to the substrate (Invention 5).

[0012] In the above inventions (Inventions 1 to 5), it is preferable that the curable composition contains a crosslinking agent (Invention 6).

[0013] In the above inventions (Inventions 1 to 6), it is preferable that the invention be for optical purposes (Invention 7). [Effects of the Invention]

[0014] The coating film according to the present invention can suppress the visibility of fingerprints not only immediately after they are applied, but also after a period of time has passed. [Modes for carrying out the invention]

[0015] 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. 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. Furthermore, the haze value of the coated film according to this embodiment is 2.0% or more and 95.0% or less, and the reflectance (%) of the surface of the coating layer opposite to the substrate is 1.0% or more and 7.0% or less.

[0016] As described above, the coated film according to this embodiment exhibits a predetermined haze value, which means that the surface of the coated layer has a predetermined fine uneven structure. Due to having such a fine surface uneven structure, fingerprints adhering to the surface of the coated layer of the coated film according to this embodiment become less noticeable. Furthermore, since the coated layer is formed by curing a curable composition containing at least one of a plasticizer and porous fine particles, the plasticizer and porous fine particles absorb the oil from the attached fingerprints, reducing the visibility of the fingerprints over time. Therefore, the coated film according to this embodiment can suppress the visibility of fingerprints not only immediately after they are applied, but also after a period of time has passed.

[0017] Furthermore, the coated film according to this embodiment satisfies the haze value described above, resulting in excellent anti-glare properties and smooth finger glide. Moreover, because the coated film according to this embodiment exhibits the reflectivity described above, the surface of the coated layer does not have excessive irregularities like those of a moth-eye film, for example, making it possible to easily wipe away any attached fingerprints.

[0018] 1. Substrate Although the substrate is not particularly limited, it is preferable to use a resin film. Particularly in the case of optical applications, it is preferable to use a resin film having a predetermined transparency.

[0019] Examples of such resin films include polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyolefin films such as polyethylene film and polypropylene film; cellophane, diacetyl cellulose film, triacetyl cellulose film, acetyl cellulose butyrate film, polyvinyl chloride film, polyvinylidene chloride film, polyvinyl alcohol film, ethylene-vinyl acetate copolymer film, polystyrene film, polycarbonate film, polymethylpentene film, polysulfone film, polyether ether ketone film, polyether sulfone film, polyether imide film, fluororesin film, polyamide film, acrylic resin film, polyurethane resin film, norbornene polymer film, cyclic olefin polymer film, cyclic conjugated diene polymer film, vinyl alicyclic hydrocarbon polymer film, and laminated films thereof. Among them, from the viewpoint of mechanical strength and the like, polyethylene terephthalate film, polycarbonate film, triacetyl cellulose film, norbornene polymer film, etc. are preferable.

[0020] In the substrate, for the purpose of improving the adhesion to the layer provided on its surface, surface treatment can be performed on one or both sides as desired 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. Examples of the roughening method include sandblasting method, solvent treatment method, etc. These surface treatment methods are appropriately selected according to the type of the substrate, but generally, the corona discharge treatment method is preferably used from the viewpoints of the effect of improving adhesion and operability.

[0021] The thickness of the base material varies depending on its type and application, but is usually preferably 25 to 5000 μm, more preferably 50 to 2000 μm, particularly preferably 75 to 1000 μm, still more preferably 90 to 500 μm, and most preferably 110 to 300 μm.

[0022] 2. Coating layer The coating layer in the present embodiment is formed by curing the above-described curable composition, and is not particularly limited as long as it can achieve the above-described haze value and reflectance conditions.

[0023] As described above, the curable composition in the present embodiment contains a curable component and at least one of a plasticizer and porous fine particles, but may contain fine particles, a photopolymerization initiator, a crosslinking agent, etc. as necessary.

[0024] (1) Curable component The curable component in the present embodiment is not particularly limited as long as it is a material having curability, and may be, for example, a thermosetting component or an active energy ray curable component. More specific examples of these curable components include polyfunctional (meth)acrylate-based monomers, (meth)acrylate-based prepolymers, urethane-based polymers, and the like.

[0025] Examples of polyfunctional (meth)acrylate monomers 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 tri(meth)acrylate. Examples of polyfunctional (meth)acrylates include 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.

[0026] Examples of (meth)acrylate-based prepolymers include polyester acrylate-based, epoxy acrylate-based, urethane acrylate-based, and polyol acrylate-based prepolymers.

[0027] 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.

[0028] 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.

[0029] Urethane acrylate-based prepolymers can be obtained, for example, by esterifying polyurethane oligomers, which are obtained by the reaction of polyether polyols or polyester polyols with polyisocyanates, with (meth)acrylic acid.

[0030] Polyol acrylate-based prepolymers can be obtained, for example, by esterifying the hydroxyl groups of a polyether polyol with (meth)acrylic acid.

[0031] 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.

[0032] 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).

[0033] The above prepolymers may be used individually or in combination of two or more.

[0034] Urethane polymers are generally obtained by reacting a polyol compound with a polyisocyanate compound. 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] (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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] (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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] (4) Fine particles The curable composition according to this embodiment may contain fine particles (fillers) other than the porous fine particles described above. By curing the curable composition containing fine particles to form a coating layer, it becomes easier to satisfy the upper limit of the haze value mentioned above.

[0051] The fine particles in this embodiment may be organic fine particles, inorganic fine particles, or resin fillers that possess both inorganic and organic properties.

[0052] Examples of organic fine particles include acrylic resin fillers (e.g., polymethyl methacrylate fillers), melamine resin fillers, acrylic-styrene copolymer fillers, polycarbonate fillers, polyethylene fillers, polystyrene fillers, and benzoguanamine resin fillers. These resins may be crosslinked. Among the above, acrylic resin fillers are preferred. In particular, polymethyl methacrylate fillers are preferred as acrylic resin fillers, and crosslinked polymethyl methacrylate fillers are even more preferred.

[0053] Examples of inorganic nanoparticles include fillers made of silica, alumina, titania, zirconia, tin oxide, indium oxide, cadmium oxide, antimony oxide, and the like.

[0054] As a resin filler that combines inorganic and organic properties, silicone fillers (for example, the Tospar series manufactured by Momentive Performance Materials Japan) are particularly preferred.

[0055] Furthermore, the above fillers may be used individually or in combination of two or more types.

[0056] When using organic fine particles, their average particle size is preferably 0.5 to 20 μm, particularly preferably 1 to 15 μm, and even more preferably 2 to 10 μm, from the viewpoint of easily satisfying the aforementioned haze value.

[0057] The content of fine particles in the curable composition of this embodiment is preferably 1 to 100 parts by mass, particularly preferably 2 to 75 parts by mass, and even more preferably 3 to 50 parts by mass, per 100 parts by mass of the curable component. This makes it easier to satisfy the haze value mentioned above.

[0058] (5) 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.

[0059] 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.

[0060] 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.

[0061] (6) 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] (7) 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.

[0067] (8) Preparation of curable compositions The curable composition in this embodiment can be prepared by mixing at least one of a curable component, a plasticizer, and porous fine particles, and optionally fine particles, a crosslinking agent, a photopolymerization initiator, an additive, etc., preferably in a solvent.

[0068] 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.

[0069] 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.

[0070] (9) 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.

[0071] 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.

[0072] 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.

[0073] 4. Method for manufacturing coated film The method for manufacturing the coated film according to this embodiment is not limited as long as it can produce a coated film that satisfies the haze value and reflectance conditions described above. 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.

[0074] 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.

[0075] 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.

[0076] 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 70 to 130°C, and the heating time is preferably 0.2 to 2 minutes, particularly preferably 0.5 to 1 minute.

[0077] 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.

[0078] Between the drying and curing processes, a step may be performed to laminate the uneven surface of a laminated substrate onto the side of the coating layer opposite to the substrate. By curing the coating layer with such a laminated substrate laminated on it, the uneven surface of the laminated substrate is transferred to the surface of the formed coating layer, making it easier to achieve the aforementioned haze value and reflectance.

[0079] The bonding substrate is not particularly limited, but any resin film having a predetermined surface texture can be used. The resin film used here is the one described above for the substrate.

[0080] Furthermore, the arithmetic mean surface roughness Ra of the uneven surface of the resin film is preferably 30 nm or more, particularly preferably 40 nm or more, and even more preferably 50 nm or more, from the viewpoint of facilitating the formation of desired irregularities in the coating layer. On the other hand, the arithmetic mean surface roughness Ra is preferably 1000 nm or less, particularly preferably 800 nm or less, and even more preferably 700 nm or less, from the viewpoint of facilitating the peeling of the resin film from the formed coating layer and suppressing an excessive increase in the surface roughness of the formed coating layer surface, thereby facilitating the achievement of better visibility.

[0081] 5. Physical properties of the coating film In the coated film according to this embodiment, as described above, the haze value is 2.0% or more and 95.0% or less. However, from the viewpoint of making fingerprints less noticeable, the haze value is preferably 5.0 to 90.0%, and particularly preferably 10.0 to 40.0%. Details of the method for measuring the haze value are described in the test examples below.

[0082] The total light transmittance of the coated film according to this embodiment is preferably 80.0% or higher, particularly preferably 85.0% or higher, and even more preferably 88.0% or higher. This results in very high transparency, making it suitable for optical applications (for display elements). The upper limit of the total light transmittance is not particularly limited and may be 100%, or slightly higher than 100% due to measurement constraints. Details of the method for measuring the total light transmittance are described in the test examples below.

[0083] In the coated film according to this embodiment, as described above, the reflectance of the surface of the coating layer opposite to the substrate is 1.0% or more and 7.0% or less. However, from the viewpoint of making it easier to minimize the difference in reflectance between areas with and without fingerprints, and thereby making fingerprints less noticeable, the reflectance is preferably 6.5% or less, and particularly preferably 6.0% or less. Furthermore, from the viewpoint of maintaining the transmittance of the coated film and easily improving the visibility of the display image, the reflectance is preferably 2.0% or more, and particularly preferably 3.0% or more. Details of the method for measuring reflectance are described in the test examples below.

[0084] In the coated film according to this embodiment, the 60° gloss measured on the coated layer side is preferably 0 to 130%, particularly preferably 5 to 100%, and even more preferably 10 to 80%, from the viewpoint of easily improving visibility and anti-glare properties immediately after fingerprint adhesion. Details of the method for measuring the 60° gloss are described in the test examples below.

[0085] In the coated film according to this embodiment, from the viewpoint of making the displayed content easily and clearly visible on the display device in which the coated film is used, the transmission clarity (image clarity) is preferably 10 to 470%, particularly preferably 20 to 440%, and even more preferably 40 to 400%, when expressed as the sum of the transmission clarity values ​​obtained by optical combs with comb widths of 0.125 mm, 0.25 mm, 0.5 mm, 1.0 mm, and 2.0 mm. Details of the method for measuring the above transmission clarity are described in the test examples below.

[0086] In the coated film according to this embodiment, the arithmetic mean surface roughness Ra of the surface of the coated layer opposite the substrate is preferably 0.03 μm or more, particularly preferably 0.04 μm or more, and even more preferably 0.05 μm or more. This results in a fine uneven structure being present on the surface of the coated layer, making attached fingerprints less noticeable. On the other hand, the arithmetic mean surface roughness Ra is preferably 1.5 μm or less, particularly preferably 1.2 μm or less, and even more preferably 1.0 μm or less. This suppresses the unevenness of the surface of the coated layer to an appropriate level, making it easier to wipe off attached fingerprints. Details of the method for measuring the arithmetic mean surface roughness Ra are described in the test examples below.

[0087] In the coated film according to this embodiment, the ten-point average surface roughness Rzjis of the surface of the coated layer opposite the substrate is preferably 0.2 μm or more, particularly preferably 0.5 μm or more, and even more preferably 1.0 μm or more. This results in a fine uneven structure on the surface of the coated layer, making attached fingerprints less noticeable. On the other hand, the ten-point average surface roughness Rzjis is preferably 20 μm or less, particularly preferably 15 μm or less, and even more preferably 10 μm or less. This keeps the unevenness of the coated layer surface to a moderate level, making it easier to wipe off attached fingerprints. Details of the method for measuring the ten-point average surface roughness Rzjis are described in the test examples below.

[0088] 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. 2 When 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.

[0089] 6. How to use the coating film The coating film according to this embodiment can be used in any application where fingerprint resistance is required, and is particularly suitable for optical applications. Specifically, the coating film according to this embodiment can be used as a surface layer for various displays (displays) such as liquid crystal displays, organic EL displays, and touch panels. More specifically, it is preferable to laminate it onto a cover material in a display having a display module such as a liquid crystal (LCD) module, a light-emitting diode (LED) module, or an organic electroluminescent (OLED) module. Lamination of the coating film onto the cover material is preferably done by attaching it via the adhesive layer described above.

[0090] 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]

[0091] 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.

[0092] [Example 1] 100 parts by mass (based on solid content; the same applies hereinafter) of polyfunctional urethane acrylate (manufactured by Arakawa Chemical Industries, Ltd., product name "Beamset 577CB"), which is an active energy ray curable component, 10 parts by mass of tributyl acetyl citrate as a plasticizer, and 18 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 40% by mass.

[0093] The above coating solution was applied to one side of a polyethylene terephthalate film (manufactured by Toyobo Co., Ltd., product name "Cosmoshine A4360", thickness: 125 μm) as a substrate using a wire bar. The resulting coating layer was dried at 70°C for 1 minute. Then, the uneven surface of a film with an uneven surface on one side (manufactured by Lintec Corporation, product name "H239-125", Ra: 46 nm) as a laminating substrate was laminated to the side of the coating layer opposite to the substrate, and the coating layer was cured by ultraviolet irradiation from the laminating substrate side under the following conditions to form a coating layer. [Ultraviolet irradiation conditions] Irradiation device: iGraphics Co., Ltd., "iGrantage ECS-401GX model" Light source: High-pressure mercury lamp Irradiation conditions Lamp output: 2kW Conveyor speed: 4.23 m / min Illuminance: 240mW / cm 2 Light amount: 307mJ / cm 2

[0094] Subsequently, the laminated substrate was peeled off the coating layer to obtain a coated film consisting of the substrate and the coating layer. The thickness of the coating layer was measured to be 5 μm.

[0095] [Example 2, Comparative Example 1] A coated film was obtained in the same manner as in Example 1, except that the composition of the curable composition and the bonding substrate used were changed as shown in Table 1. Details of each component in Table 1 are shown in Table 2.

[0096] [Examples 3, 4] A coated film was obtained in the same manner as in Example 1, except that the composition of the curable composition was changed as shown in Table 1, and the bonding substrate was not laminated to the coated layer.

[0097] [Example 5] 100 parts by mass of a thermosetting component, a urethane acrylate prepolymer (manufactured by Tokushiki Co., Ltd., product name "AU-2513* solids content 40%", weight-average molecular weight: 32000, containing a silicone-based leveling agent), 25 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 toluene as a diluent to obtain a coating solution of a curable composition with a solids content of 40% by mass.

[0098] The above coating solution was applied to one side of a polyethylene terephthalate film (manufactured by Toyobo Co., Ltd., product name "Cosmoshine A4360", thickness: 125 μm) as a substrate using a wire bar. The resulting coating layer was dried at 120°C for 1 minute. Then, the uneven surface of a film with an uneven surface on one side (manufactured by Lintec Corporation, product name "H251-188", Ra: 603 nm), which served as a bonding substrate, was laminated to the side of the coating layer opposite to the substrate. The film was then cured at room temperature for 3 days. As a result, the coating layer hardened and became a coating layer. The bonding substrate was then peeled off from the coating layer to obtain a coated film consisting of the substrate and the coating layer. The thickness of the coating layer was measured to be 5 μm.

[0099] [Example 6, Comparative Example 2] A coated film was obtained in the same manner as in Example 5, except that the composition of the curable composition and the bonding substrate used were changed as shown in Table 1.

[0100] [Comparative Example 3] A coated film was obtained in the same manner as in Example 5, except that the composition of the curable composition was changed as shown in Table 1, and the bonding substrate was not laminated to the coated layer.

[0101] [Reference example] A commercially available moth-eye film was prepared and used as a reference example.

[0102] [Test Example 1] (Measurement of haze value and total light transmittance) The haze value (%) and total light transmittance (%) of the coated films produced in the examples and comparative examples were measured using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., product name "SH-7000"). The results are shown in Table 3.

[0103] [Test Example 2] (Measurement of 60° gross) The 60° gloss (%) of the coated film side of the coated film prepared in the examples and comparative examples was measured using a gloss meter (manufactured by Nippon Denshoku Industries Co., Ltd., product name "VG7000"). The results are shown in Table 3.

[0104] [Test Example 3] (Measurement of transmission clarity) For the coated films prepared in the examples and comparative examples, the transmission clarity (image clarity) was measured using an image clarity meter (manufactured by Suga Test Instruments Co., Ltd., product name "ICM-1T"), with light incident from the coated layer side, in accordance with the transmission method of JIS K7374:2007. The comb widths of the optical combs used in the image clarity meter were 0.125 mm, 0.25 mm, 0.5 mm, 1.0 mm, and 2.0 mm. The total value (%) of the transmission clarity measured for each optical comb is shown in Table 3.

[0105] [Test Example 4] (Measurement of surface roughness) The arithmetic mean surface roughness Ra (μm) and ten-point mean surface roughness Rzjis (μm) of the coated films prepared in the examples and comparative examples were measured using a contact-type roughness meter (Mitutoyo Corporation, product name "SV3000S4"), which are obtained from roughness curves measured in accordance with JIS B0601-1994. The results are shown in Table 3.

[0106] [Test Example 5] (Evaluation of fingerprint resistance) The substrate-side surface of the coated films prepared in the examples and comparative examples was bonded to one side of a black acrylic plate (manufactured by Mitsubishi Rayon Co., Ltd., product name "Acrylite L502") using an acrylic transparent adhesive (refractive index: 1.49, haze: <1.0%).

[0107] Fingerprints were then applied to the coated surface, and the fingerprints were visually evaluated under fluorescent lighting immediately after application and 24 hours later. Fingerprint resistance was evaluated based on the following criteria. The results are shown in Table 3. 3 points: Fingerprints are barely visible. Point 2: Fingerprints are visible. 1 point: Fingerprints are clearly visible.

[0108] [Test Example 6] (Evaluation of finger glide) The substrate-side surface of the coated films prepared in the examples and comparative examples was bonded to one side of a black acrylic plate (manufactured by Mitsubishi Rayon Co., Ltd., product name "Acrylite L502") using an acrylic transparent adhesive (refractive index: 1.49, haze: <1.0%).

[0109] Then, the finger-slipperiness was evaluated by sliding a finger across the surface of the court layer and comparing the tactile sensation against the following criteria. The results are shown in Table 3. 5 points: Fingers glide smoothly. 4 points: Fingers slip. 3 points: My fingers slip a little. Two points: My fingers don't slide very easily. 1 point: My finger gets caught.

[0110] [Test Example 7] (Evaluation of anti-glare properties) The substrate-side surface of the coated films prepared in the examples and comparative examples was bonded to one side of a black acrylic plate (manufactured by Mitsubishi Rayon Co., Ltd., product name "Acrylite L502") using an acrylic transparent adhesive (refractive index: 1.49, haze: <1.0%).

[0111] Then, a three-wavelength fluorescent lamp was reflected onto the surface of the coated layer, and the degree of reflection observed visually was compared against the following criteria to evaluate the anti-glare properties. The results are shown in Table 3. 5 points: The outline of the fluorescent light is completely invisible. 4 points: The outline of the fluorescent light is blurred. 3 points: The outline of the fluorescent light is slightly blurred. 2 points: The outlines of the fluorescent lights are slightly blurred. 1 point: The outline of the fluorescent light is clearly visible.

[0112] 〔Test Example 8〕(Evaluation of Abrasion Resistance) For the coated films prepared in the Examples and Comparative Examples and the moth-eye film as a Reference Example, the surface on the coated layer side of the coated film and the surface on the moth-eye structure side of the moth-eye film were rubbed 10 times back and forth with #0000 steel wool under a load of 125 g / cm 2 . The test range was set to a range of 100 mm in length × 20 mm in width (reciprocated in the length direction). The number of scratches in that test range was counted visually under a three-wavelength fluorescent lamp, and the abrasion 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.

[0113] 〔Test Example 9〕(Measurement of Reflectance) For the coated films prepared in the Examples and Comparative Examples and the moth-eye film as a Reference Example, the surface on the coated layer side of the coated film and the surface on the moth-eye structure side of the moth-eye film were 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%).

[0114] Then, using a spectrophotometer (manufactured by Shimadzu Corporation, product name "UV-3600i Plus"), the reflectance from 360 to 830 nm was measured, and the average value was taken as the reflectance (%). The results are shown in Table 3.

[0115]

Table 1

[0116]

Table 2

[0117] [Table 3]

[0118] As can be seen from Table 3, the coated films obtained in the examples exhibited excellent fingerprint resistance both immediately after application and 24 hours later. Furthermore, other optical properties were also sufficiently excellent. [Industrial applicability]

[0119] The coating film of the present invention is suitably used as a surface layer for touch panels and the like, where fingerprint resistance is required.

Claims

1. A coated film comprising a base material and a coating layer provided on at least one side of the base material, 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 haze value of the aforementioned coating film is 2.0% or more and 95.0% or less. The reflectance of the surface of the coating layer opposite to the substrate is 1.0% or more and 7.0% or less. A coating film characterized by the following features.

2. The coated film according to claim 1, characterized in that the arithmetic mean surface roughness Ra of the surface of the coated layer opposite to the substrate is 0.03 μm or more and 1.5 μm or less.

3. On the surface of the coating layer opposite to the substrate, 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.

4. The coated film according to claim 1, characterized in that the curable composition contains fine particles other than the porous fine particles.

5. The coated film according to claim 1, characterized in that it is manufactured by applying the curable composition to the substrate to form a coating layer, and then curing the coating layer with the uneven surface of a laminated substrate having an uneven surface laminated on the side of the coating layer opposite to the substrate, thereby forming the coated layer.

6. The coating film according to claim 1, characterized in that the curable composition contains a crosslinking agent.

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

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