Anti-reflective film with adhesive sheet and image display device

Abstract

To provide an antireflection film with an adhesive sheet which is suitable for use in an organic EL display device (OLED).SOLUTION: An antireflection film with an adhesive sheet 10 includes an adhesive sheet 1 and an antireflection film 2. The antireflection film with an adhesive sheet 10 does not include a polarizer. The adhesive sheet 1 has a surface resistivity of 9×1011 Ω / sq. or less. An image display device 21 includes, for example, the antireflection film with an adhesive sheet 10.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to an anti-reflective film with an adhesive sheet and an image display device. [Background technology]

[0002] In recent years, image display devices, such as electroluminescent (EL) displays and liquid crystal displays, have become rapidly widespread. These image display devices have a laminated structure comprising, for example, an image-forming layer such as an EL light-emitting layer or a liquid crystal layer, and an optical laminate including an optical film and an adhesive sheet. The adhesive sheet is mainly used for bonding between films included in the optical laminate, and for bonding between the image-forming layer and the optical laminate. Examples of optical films include polarizing plates, phase difference films, and polarizing plates with phase difference films that integrate a polarizing plate and a phase difference film.

[0003] In EL display devices, a circular polarizer, which includes a polarizer and a phase difference film, is sometimes used as an optical film to suppress the reflection of light incident into the device (for example, Patent Document 1). However, because the polarizer contained in the circular polarizer absorbs light from the EL light-emitting layer, EL display devices that include a circular polarizer tend to have low brightness of the light emitted from the device. Also, if the light emission intensity of the element is increased to obtain the desired brightness, the required power consumption increases. Patent Documents 2 and 3 disclose EL display devices that use a film with anti-reflective properties instead of a circular polarizer. Examples of films with anti-reflective properties include films with anti-reflection (AR) functionality, anti-glare (AG) functionality, or both of these functions. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2003-332068 [Patent Document 2] Japanese Patent Publication No. 2018-112715 [Patent Document 3] Japanese Patent Application Laid-Open No. 2009-70815 Summary of the Invention Problem to be Solved by the Invention

[0005] An organic EL display device (hereinafter referred to as OLED), which is a type of EL display device, is sometimes incorporated with a touch panel. However, when the display portion of the OLED is touched with a finger, unintended light emission may occur in the OLED. In consideration of the further higher definition and excellent color development performance required for OLEDs, it is desired to suppress the above-mentioned unintended light emission.

[0006] Accordingly, an object of the present invention is to provide an antireflection film with an adhesive sheet suitable for use in OLEDs. Means for Solving the Problem

[0007] The present invention provides: An antireflection film with an adhesive sheet, comprising an adhesive sheet and an antireflection film, wherein the antireflection film with an adhesive sheet does not contain a polarizer, and the adhesive sheet has a surface resistivity of 9×10 11 Ω / □ or less, which is the antireflection film with an adhesive sheet provided by the present invention.

[0008] In another aspect, the present invention provides: An image display device comprising the antireflection film with an adhesive sheet according to the present invention described above. Effect of the Invention

[0009] According to studies by the present inventors, unintended light emission of an OLED when the display portion is touched is mainly caused by electrostatic charging generated by contact, and charging of the OLED can be suppressed by using the antireflection film with an adhesive sheet described above. Therefore, the antireflection film with an adhesive sheet of the present invention is suitable for use in OLEDs. Brief Description of the Drawings

[0010] [Figure 1] Figure 1 is a schematic cross-sectional view showing an example of the anti-reflective film with adhesive sheet according to the present invention. [Figure 2] Figure 2 is a schematic cross-sectional view showing an example of an anti-reflective film. [Figure 3] Figure 3 is a schematic cross-sectional view showing another example of the anti-reflective film with adhesive sheet according to the present invention. [Figure 4] Figure 4 is a schematic cross-sectional view showing an example of the image display device of the present invention. [Figure 5] Figure 5 is a schematic cross-sectional view showing another example of the image display device of the present invention. [Modes for carrying out the invention]

[0011] Embodiments of the present invention will be described below with reference to the drawings. The present invention is not limited to the embodiments shown below.

[0012] In this specification, "(meth)acrylic" means acrylic and methacrylic. Similarly, "(meth)acrylate" means acrylate and methacrylate.

[0013] [Anti-reflective film with adhesive backing] As shown in Figure 1, the anti-reflective film 10 (10A) with adhesive sheet of this embodiment comprises an adhesive sheet 1 and an anti-reflective film 2, and for example, is composed only of the adhesive sheet 1 and the anti-reflective film 2. The adhesive sheet 1 is, for example, placed on the surface of the anti-reflective film 2 and bonded to the anti-reflective film 2. The anti-reflective film 10A with adhesive sheet can be bonded to an object (for example, the image forming layer of an image display device) via the adhesive sheet 1. The anti-reflective film 10A with adhesive sheet does not include a polarizer. In particular, the anti-reflective film 10A with adhesive sheet does not include a polarizer or a circular polarizer. The anti-reflective film 10A with adhesive sheet may not include a phase difference film.

[0014] [Pressure-sensitive adhesive sheet] The pressure-sensitive adhesive sheet 1 has 9×10 11 Ω / □ or less surface resistivity. The surface resistivity of the pressure-sensitive adhesive sheet 1 may be 5×10 11 Ω / □ or less, 1×10 11 Ω / □ or less, 9×10 10 Ω / □ or less, 5×10 10 Ω / □ or less, 3×10 10 Ω / □ or less, 1×10 10 Ω / □ or less, 9×10 9 Ω / □ or less, 5×10 9 Ω / □ or less, 3×10 9 Ω / □ or less, 2×10 9 Ω / □ or less, and further 1×10 9 Ω / □ or less. The lower limit of the surface resistivity is, for example, 1×10 7 Ω / □ or more. The surface resistivity of the pressure-sensitive adhesive sheet 1 can be evaluated, for example, with a high-resistance resistivity meter (for example, Hiresta series manufactured by Mitsubishi Chemical Analytech).

[0015] The pressure-sensitive adhesive sheet 1 is, for example, a sheet formed from a pressure-sensitive adhesive composition (I) containing a (meth)acrylic polymer (A). The pressure-sensitive adhesive sheet 1 formed from the pressure-sensitive adhesive composition (I) contains, for example, a cured product of the (meth)acrylic polymer (A). However, the pressure-sensitive adhesive sheet 1 is not limited to the above example.

[0016] (Pressure-sensitive Adhesive Composition) <(Meth)acrylic polymer (A)> The pressure-sensitive adhesive composition (I) contains, for example, the (meth)acrylic polymer (A) as a main component. In other words, the pressure-sensitive adhesive composition (I) is an acrylic pressure-sensitive adhesive composition. The main component means the component having the highest content ratio in the composition. The content of the main component is, for example, 50% by weight or more, and may be 60% by weight or more, 70% by weight or more, 75% by weight or more, and further 80% by weight or more.

[0017] The (meth)acrylic polymer (A) preferably has structural units derived from a (meth)acrylic monomer (A1) having an alkyl group having 1 to 30 carbon atoms in its side chain. The (meth)acrylic polymer (A) may have the above structural units as its main units. The alkyl group may be linear or branched. The (meth)acrylic polymer (A) may have one or more structural units derived from the (meth)acrylic monomer (A1). Examples of (meth)acrylic monomers (A1) include methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, isobutyl (meth)acrylate, n-pentyl (meth)acrylate, isopentyl (meth)acrylate, n-hexyl (meth)acrylate, isohexyl (meth)acrylate, isoheptyl (meth)acrylate These are ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, n-dodecyl (meth)acrylate (lauryl (meth)acrylate), n-tridecyl (meth)acrylate, and n-tetradecyl (meth)acrylate. In this specification, "principal unit" means a unit that accounts for, for example, 50% by weight or more, preferably 60% by weight or more, more preferably 70% by weight or more, and even more preferably 80% by weight or more of the total constituent units of the polymer.

[0018] The (meth)acrylic polymer (A) may have constituent units derived from a (meth)acrylic monomer (A1) having a long-chain alkyl group as a side chain. An example of such monomer (A1) is n-dodecyl (meth)acrylate (lauryl (meth)acrylate). In this specification, "long-chain alkyl group" means an alkyl group having 6 to 30 carbon atoms.

[0019] The (meth)acrylic polymer (A) may have constituent units derived from a (meth)acrylic monomer (A1) whose glass transition temperature (Tg) is in the range of -70 to -20°C when it is a homopolymer. An example of such monomer (A1) is n-butyl acrylate.

[0020] The (meth)acrylic polymer (A) may have constituent units other than those derived from the (meth)acrylic monomer (A1). These constituent units are derived from monomers (A2) copolymerizable with the (meth)acrylic monomer (A1). The (meth)acrylic polymer (A) may have one or more of these constituent units.

[0021] An example of monomer (A2) is an aromatic ring-containing monomer. The aromatic ring-containing monomer may also be an aromatic ring-containing (meth)acrylic monomer. Examples of aromatic ring-containing monomers are phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, benzyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, ethylene oxide-modified nonylphenol (meth)acrylate, hydroxyethylated β-naphthol (meth)acrylate, and biphenyl (meth)acrylate. The content of constituent units derived from aromatic ring-containing monomers in (meth)acrylic polymer (A) may be, for example, 0 to 50% by weight, and may also be 1 to 30% by weight, 5 to 25% by weight, 8 to 20% by weight, 10 to 19% by weight, or even 13 to 18% by weight, or even 0% by weight (no such constituent units are included).

[0022] Another example of monomer (A2) is a hydroxyl group-containing monomer. The hydroxyl group-containing monomer may be a hydroxyl group-containing (meth)acrylic monomer. Examples of hydroxyl group-containing monomers are hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate and 12-hydroxylauryl (meth)acrylate, as well as (4-hydroxymethylcyclohexyl)-methyl acrylate. The content of constituent units derived from hydroxyl group-containing monomers in (meth)acrylic polymer (A) may be 5% by weight or less, 3% by weight or less, 2% by weight or less, 1% by weight or less, 0.5% by weight or less, or even 0% by weight or less (no such constituent units are included).

[0023] Another example of monomer (A2) is the (meth)acrylate shown in the following chemical formula (1). R in equation (1) 1 This is either a hydrogen atom or a methyl group. Equation (1) R 2 This is an alkyl group. The alkyl group may be linear or branched. R 2 The alkyl group is preferably a linear alkyl group. R 2 Examples include the methyl group and the ethyl group. In formula (1), n ​​is an integer from 1 to 15. [ka]

[0024] Examples of (meth)acrylates shown in formula (1) are 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, and methoxytriethylene glycol (meth)acrylate, preferably 2-methoxyethyl acrylate (MEA). The constituent units derived from the (meth)acrylate of formula (1) can contribute to reducing the surface resistivity of the adhesive sheet 1. In particular, the constituent units derived from the (meth)acrylate of formula (1) tend to reduce the surface resistivity of the adhesive sheet 1 while suppressing the amount of antistatic agent (B) described later. The (meth)acrylic polymer (A) may have the constituent units derived from the (meth)acrylate of formula (1) as its main units.

[0025] Monomer (A2) may be a carboxyl group-containing monomer, an amino group-containing monomer, or an amide group-containing monomer. Examples of carboxyl group-containing monomers are (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. Examples of amino group-containing monomers are N,N-dimethylaminoethyl (meth)acrylate and N,N-dimethylaminopropyl (meth)acrylate. Examples of amide group-containing monomers include acrylamide monomers such as (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-isopropylacrylamide, N-methyl(meth)acrylamide, N-butyl(meth)acrylamide, N-hexyl(meth)acrylamide, N-methylol(meth)acrylamide, N-methylol-N-propane(meth)acrylamide, aminomethyl(meth)acrylamide, aminoethyl(meth)acrylamide, mercaptomethyl(meth)acrylamide, and mercaptoethyl(meth)acrylamide; N-acryloyl heterocyclic monomers such as N-(meth)acryloylmorpholin, N-(meth)acryloylpiperidine, and N-(meth)acryloylpyrrolidine; and N-vinyl group-containing lactam monomers such as N-vinylpyrrolidone and N-vinyl-ε-caprolactam.

[0026] Monomer (A2) may be a polyfunctional monomer. Examples of polyfunctional monomers include polyfunctional acrylates such as hexanediol di(meth)acrylate (1,6-hexanediol di(meth)acrylate), butanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, trimethylolpropane tri(meth)acrylate, tetramethylolmethane tri(meth)acrylate, allyl(meth)acrylate, vinyl(meth)acrylate, epoxy acrylate, polyester acrylate and urethane acrylate; and divinylbenzene. The polyfunctional acrylate is preferably 1,6-hexanediol diacrylate or dipentaerythritol hexa(meth)acrylate.

[0027] The total content of constituent units derived from carboxyl group-containing monomers, amino group-containing monomers, amide group-containing monomers, and polyfunctional monomers in the (meth)acrylic polymer (A) is preferably 20% by weight or less, more preferably 10% by weight or less, and even more preferably 8% by weight or less. If the (meth)acrylic polymer (A) contains such constituent units, the total content may be, for example, 0.01% by weight or more, and may be 1% by weight or more, 2% by weight or more, or even 3% by weight or more. The (meth)acrylic polymer (A) does not have to contain constituent units derived from polyfunctional monomers.

[0028] Other examples of monomers (A2) include epoxy group-containing monomers such as glycidyl (meth)acrylate and methylglycidyl (meth)acrylate; sulfonic acid group-containing monomers such as sodium vinyl sulfonate; phosphate group-containing monomers; (meth)acrylate esters having alicyclic hydrocarbon groups such as cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate and isobornyl (meth)acrylate; vinyl esters such as vinyl acetate and vinyl propionate; aromatic vinyl compounds such as styrene and vinyltoluene; olefins or dienes such as ethylene, propylene, butadiene, isoprene and isobutylene; vinyl ethers such as vinyl alkyl ethers; and vinyl chloride.

[0029] The total content of constituent units derived from the above-mentioned other monomers (A2) in the (meth)acrylic polymer (A) is, for example, 30% by weight or less, may be 10% by weight or less, and preferably 0% by weight (not containing the constituent units).

[0030] The (meth)acrylic polymer (A) can be formed by polymerizing one or more of the above-mentioned monomers by known methods. The monomers and partial polymers of the monomers may also be polymerized. Polymerization can be carried out by, for example, solution polymerization, emulsion polymerization, bulk polymerization, thermal polymerization, or active energy ray polymerization. From the viewpoint of forming an adhesive sheet with excellent optical transparency, solution polymerization and active energy ray polymerization are preferred. Polymerization is preferably carried out while avoiding contact between the monomers and / or partial polymers and oxygen. For this purpose, polymerization can be carried out, for example, under an inert gas atmosphere such as nitrogen, or under conditions where oxygen is blocked by a resin film or the like. The (meth)acrylic polymer (A) to be formed may be in any form such as a random copolymer, block copolymer, or graft copolymer.

[0031] The polymerization system that forms the (meth)acrylic polymer (A) may contain one or more polymerization initiators. The type of polymerization initiator can be selected based on the polymerization reaction, and may be, for example, a thermal polymerization initiator or a photopolymerization initiator.

[0032] Solvents used in solution polymerization include, for example, esters such as ethyl acetate and n-butyl acetate; aromatic hydrocarbons such as toluene and benzene; aliphatic hydrocarbons such as n-hexane and n-heptane; alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; and ketones such as methyl ethyl ketone and methyl isobutyl ketone. However, the solvent is not limited to the above examples. The solvent may be a mixture of two or more solvents.

[0033] Polymerization initiators used in solution polymerization include, for example, azo polymerization initiators, peroxide polymerization initiators, and redox polymerization initiators. Examples of peroxide polymerization initiators include dibenzoyl peroxide and t-butyl permaleate. Among these, the azo polymerization initiator disclosed in Japanese Patent Application Publication No. 2002-69411 is preferred. Examples of such azo polymerization initiators include 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis-2-methylbutyronitrile, 2,2'-azobis(2-methylpropionic acid)dimethyl, and 4,4'-azobis-4-cyanovaleric acid. However, the polymerization initiator is not limited to the above examples. The amount of azo polymerization initiator used is, for example, 0.05 to 0.5 parts by weight per 100 parts by weight of the total amount of monomer, and may also be 0.1 to 0.3 parts by weight.

[0034] The active energy rays used in active energy ray polymerization include, for example, ionizing radiation such as alpha rays, beta rays, gamma rays, neutron rays, and electron beams, as well as ultraviolet rays. Ultraviolet rays are preferred as the active energy rays. Polymerization by irradiation with ultraviolet rays is also called photopolymerization. The polymerization system for active energy ray polymerization typically includes a photopolymerization initiator. The polymerization conditions for active energy polymerization are not limited as long as a (meth)acrylic polymer (A) is formed.

[0035] Examples of photopolymerization initiators include benzoin ether-based photopolymerization initiators, acetophenone-based photopolymerization initiators, α-ketol-based photopolymerization initiators, aromatic sulfonyl chloride-based photopolymerization initiators, photoactive oxime-based photopolymerization initiators, benzoin-based photopolymerization initiators, benzyl-based photopolymerization initiators, benzophenone-based photopolymerization initiators, ketal-based photopolymerization initiators, and thioxanthone-based photopolymerization initiators. However, the photopolymerization initiators are not limited to the examples above.

[0036] Benzoin ether-based photopolymerization initiators include, for example, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1,2-diphenylethane-1-one, and anisole methyl ether. Acetophenone-based photopolymerization initiators include, for example, 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexylphenyl ketone, 4-phenoxydichloroacetophenone, and 4-(t-butyl)dichloroacetophenone. Alpha-ketol-based photopolymerization initiators include, for example, 2-methyl-2-hydroxypropiophenone and 1-[4-(2-hydroxyethyl)phenyl]-2-methylpropan-1-one. Aromatic sulfonyl chloride-based photopolymerization initiators include, for example, 2-naphthalenesulfonyl chloride. Photoactive oxime-based photopolymerization initiators include, for example, 1-phenyl-1,1-propanedione-2-(o-ethoxycarbonyl)-oxime. Benzoin-based photopolymerization initiators include, for example, benzoin. Benzyl-based photopolymerization initiators include, for example, benzyl. Benzophenone-based photopolymerization initiators include, for example, benzophenone, benzoylbenzoic acid, 3,3'-dimethyl-4-methoxybenzophenone, polyvinylbenzophenone, and α-hydroxycyclohexylphenyl ketone. Ketal-based photopolymerization initiators include, for example, benzyldimethylketal. Thioxanthone-based photopolymerization initiators include, for example, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, and dodecylthioxanthone.

[0037] The amount of photopolymerization initiator used is, for example, 0.01 to 1 part by weight per 100 parts by weight of the total amount of monomer, and may also be 0.05 to 0.5 parts by weight.

[0038] The weight-average molecular weight (Mw) of the (meth)acrylic polymer (A) is, for example, 1 million to 2.8 million, and may be 1.2 million or more, or even 1.4 million or more, from the viewpoint of durability and heat resistance of the adhesive sheet. The weight-average molecular weight (Mw) of polymers and oligomers in this specification is a value (polystyrene equivalent) based on GPC (gel permeation chromatography) measurement.

[0039] The content of the (meth)acrylic polymer (A) in the adhesive composition (I) is, for example, 50% by weight or more in terms of solid content, and may be 60% by weight or more, 70% by weight or more, or even 80% by weight or more. The upper limit of the content is, for example, 99% by weight or less, and may be 97% by weight or less, 95% by weight or less, 93% by weight or less, or even 90% by weight or less.

[0040] <Antistatic agent (B)> The adhesive composition (I) further comprises, for example, an antistatic agent (B). The amount of antistatic agent (B) is, for example, less than 10 parts by weight per 100 parts by weight of (meth)acrylic polymer (A), and may be 8 parts by weight or less, 7 parts by weight or less, 6 parts by weight or less, 5 parts by weight or less, 4 parts by weight or less, 3 parts by weight or less, 2 parts by weight or less, 1 part by weight or less, 0.8 parts by weight or less, 0.6 parts by weight or less, 0.5 parts by weight or less, 0.3 parts by weight or less, 0.1 parts by weight or less, and even 0.05 parts by weight or less. The lower limit of the amount is, for example, 0.005 parts by weight or more. Touch panels are sometimes incorporated inside image display devices, such as OLEDs used in portable devices such as smartphones. On-cell displays also exist in which the touch panel is positioned on the viewing side of the image forming layer. Touch panels usually contain a conductive layer such as a metal layer, but according to the inventors' studies, conductive layers, especially metal layers, are susceptible to corrosion by the antistatic agent (B). From this perspective, the lower the amount of antistatic agent (B) added, the more suitable the adhesive composition (I) is for use on OLEDs.

[0041] An example of the antistatic agent (B) is an ionic compound such as a salt. The ionic compound may be an ionic liquid that is liquid at room temperature (25°C). Compared to conductive fine particles, for example, ionic compounds generally have higher compatibility with the adhesive composition (I) and are suitable for forming adhesive sheets with excellent optical transparency. Note that the adhesive composition (I) does not have to substantially contain conductive fine particles. In this specification, "substantially contained in the adhesive composition (I)" means that the content is 0.5 parts by weight or less, preferably 0.1 parts by weight or less, more preferably 0.05 parts by weight or less, and even more preferably 0.01 parts by weight or less, per 100 parts by weight of the (meth)acrylic polymer (A).

[0042] Examples of cations constituting ionic compounds are metal ions and onium ions. Examples of metal ions are alkali metal ions and alkaline earth metal ions. Alkali metal ions include, for example, lithium ions, sodium ions, and potassium ions, and may also be lithium ions. Alkaline earth metal ions include, for example, magnesium ions and calcium ions. However, metal ions are not limited to the above examples.

[0043] An example of an onium ion is an ion in which at least one atom selected from nitrogen, phosphorus, and sulfur atoms is positively charged (+). The onium ion may also be an organic ion, in which case it may be an ion of a cyclic organic compound or an ion of a chain-like organic compound. The cyclic organic compound may be aromatic or non-aromatic, such as an aliphatic compound. Examples of onium ions include quaternary ammonium ions such as N-ethyl-N,N-dimethyl-N-(2-methoxyethyl)ammonium ion, N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium ion, N-ethyl-N,N-dimethyl-N-propylammonium ion, N-methyl-N,N,N-trioctylammonium ion, N,N,N-trimethyl-N-propylammonium ion, tetrabutylammonium ion, tetramethylammonium ion, tetrahexylammonium ion, and N-methyl-N,N,N-tributylammonium ion. These include: pyridinium ions such as N-alkylpyridinium ions substituted with C4-C16 alkyl groups; imidazolium ions such as 1,3-alkylmethylimidazolium ions substituted with C2-C10 alkyl groups (e.g., ethyl groups), and 1,2-dimethyl-3-alkylimidazolium ions substituted with C2-C10 alkyl groups; phosphonium ions, pyrrolidinium ions, pyridazinium ions, pyrimidinium ions, pyrazinium ions, pyrazolium ions, thiazolium ions, oxazolium ions, triazolium ions, and piperidinium ions. However, onium ions are not limited to the above examples.

[0044] Examples of anions that make up ionic compounds include fluorides, chlorides, bromides, iodides, and perchlorates (ClO4). - ), hydroxyl (OH - ), carbonate (CO3 2- ), nitrate (NO3 - ), sulfonate (SO4 - ), methylbenzenesulfonate (CH3(C6H4)SO3 - ), p-toluenesulfonate (CH3C6H4SO3 - ), carboxybenzenesulfonate (COOH(C6H4)SO3 - ), trifluoromethanesulfonate (CF3SO2 - ), benzoate (C6H5COO - ), acetate (CH3COO - ), trifluoroacetate (CF3COO - ), tetrafluoroborate (BF4 - ), Tetrabenzylborate (B(C6H5)4 - ), hexafluorophosphate (PF6 - ), trispentafluoroethyl trifluorophosphate (P(C2F5)3F3 - ), bisfluorosulfonyliimide (N(SO2F)2 - ), bistrifluoromethanesulfonylimide (N(SO2CF3)2 - ), bispentafluoroethanesulfonylimide (N(SOC2F5)2 - ), bispentafluoroethanecarbonylimide (N(COC2F5)2 - ), Bisperfluorobutanesulfonylimide (N(SO2C4F9)2 - ), Bisperfluorobutanecarbonylimide (N(COC4F9)2 - ), Tristrifluoromethanesulfonylmethide (C(SO2CF3)3 - ) and tristrifluoromethanecarbonylmethide (C(SO2CF3)3 - ) However, anions are not limited to the above examples.

[0045] The antistatic agent (B) may contain an anion containing a sulfur atom. An example of an anion containing a sulfur atom is bisfluorosulfonylimide (N(SO2F)2 - ) and bistrifluoromethanesulfonylimide (N(SO2CF3)2 - )

[0046] The antistatic agent (B) may be an organic salt. Alternatively, the antistatic agent (B) may be a lithium salt, and may be a lithium organic salt containing lithium ions and organic ions as cations and anions, respectively.

[0047] Specific examples of antistatic agents (B) include 1-ethyl-3-methylimidazolium bisfluorosulfonylimide, lithium bis(trifluoromethane)sulfonimide (LiTFSi), ethylmethylpyrrolidinium bis(trifluoromethanesulfonyl)imide (EMPTFSi), and tributylmethylammonium bis(trifluoromethanesulfonyl)imide (TBMATFSi).

[0048] The antistatic agent (B) does not necessarily have to contain phosphorus atoms. According to the inventors' studies, antistatic agents (B) containing phosphorus atoms tend to corrode the touch panel (or its conductive layer).

[0049] The adhesive composition (I) may contain one or more antistatic agents (B).

[0050] <UV absorber (C)> The adhesive composition (I) may or may not contain an ultraviolet absorber (C). The maximum absorption wavelength in the absorption spectrum of the ultraviolet absorber (C) is between 320 nm and 380 nm. Note that ultraviolet light with wavelengths below 320 nm is present in less ambient light than ultraviolet light with wavelengths above 320 nm, and is absorbed more by the layer located on the ambient light side (visible side) than the organic EL light-emitting layer; therefore, the need to consider degradation of the OLED due to ambient light is relatively small. The absorption spectrum can be evaluated, for example, by spectrophotometric measurement of a solution in which the ultraviolet absorber (C) is dissolved at a concentration of 0.001% by weight in a solvent such as isopropyl alcohol.

[0051] The maximum absorption wavelength in the absorption spectrum of the UV absorber (C) may be between 330 nm and 375 nm, between 335 nm and 370 nm, or between 340 nm and 370 nm. Furthermore, in an absorption spectrum normalized to a maximum value of 1, the UV absorber (C) may have an absorbance of 0.1 or higher, and even 0.2 or higher, across a wavelength band between 320 nm and 370 nm. These UV absorbers (C) are particularly suitable for suppressing the degradation of OLEDs due to ultraviolet light.

[0052] The amount of UV absorber (C) is, for example, less than 15 parts by weight per 100 parts by weight of (meth)acrylic polymer (A), and may be 10 parts by weight or less, 7 parts by weight or less, 5 parts by weight or less, 3 parts by weight or less, 2.5 parts by weight or less, 2 parts by weight or less, 1.5 parts by weight or less, 1 part by weight or less, 0.8 parts by weight or less, 0.7 parts by weight or less, 0.6 parts by weight or less, or even 0.5 parts by weight or less. The lower limit of the amount is, for example, 0.1 parts by weight or more.

[0053] The ultraviolet absorber (C) may be, for example, a triazine-based ultraviolet absorber, a benzotriazole-based ultraviolet absorber, a benzophenone-based ultraviolet absorber, an oxybenzophenone-based ultraviolet absorber, a salicylic acid ester-based ultraviolet absorber, or a cyanoacrylate-based ultraviolet absorber, as long as the maximum absorption wavelength in the absorption spectrum is between 320 nm and 380 nm. Each ultraviolet absorber is a compound having a triazine skeleton, a benzotriazole skeleton, a benzophenone skeleton, an oxybenzophenone skeleton, a salicylic acid ester structure, and a cyanoacrylate structure, respectively. The ultraviolet absorber (C) is preferably triazine-based or benzotriazole-based, and more preferably triazine-based. The triazine-based ultraviolet absorber (C) may have at least one, preferably two, more preferably three hydroxyphenyl groups and / or alkoxy (methoxy, ethoxy, propoxy, etc.)phenyl groups per molecule. Furthermore, the triazine-based ultraviolet absorber (C) may have at least one, preferably two, hydroxyphenyl groups per molecule. These UV absorbers (C), in particular UV absorbers (C) having three hydroxyphenyl groups and / or alkoxyphenyl groups in one molecule, are especially suitable for suppressing OLED degradation due to ultraviolet light because they exhibit little variation in absorbance in the wavelength range of 320 nm to 370 nm.

[0054] Examples of triazine-based UV absorbers include 2,4-bis-[{4-(4-ethylhexyloxy)-4-hydroxy}phenyl]-6-(4-methoxyphenyl)-1,3,5-triazine (Tinosorb S, manufactured by BASF) and 2,4-bis[2-hydroxy-4-butoxyphenyl]-6-(2,4-dibutoxyphenyl)-1,3,5-triazine (TINUVIN). Reaction product of 460 (BASF), 2-(4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine-2-yl)-5-hydroxyphenyl and [(C10-C16 (mainly C12-C13) alkyloxy)methyl]oxirane (TINUVIN400, BASF), 2-[4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine-2-yl]-5-[3-(dodecyloxy)-2-hydroxypropoxy]phenol), 2-(2,4-dihydroxyphenyl The reaction products of (phenyl)-4,6-bis-(2,4-dimethylphenyl)-1,3,5-triazine and (2-ethylhexyl)-glycidic acid ester are TINUVIN 405 (BASF), 2-(4,6-diphenyl-1,3,5-triazine-2-yl)-5-[(hexyl)oxy]-phenol (TINUVIN 1577 (BASF)), 2-(4,6-diphenyl-1,3,5-triazine-2-yl)-5-[2-(2-ethylhexanoyloxy)ethoxy]-phenol (ADK STAB LA46 (ADEKA)), and 2-(2-hydroxy-4-[1-octyloxycarbonylethoxy]phenyl)-4,6-bis(4-phenylphenyl)-1,3,5-triazine (TINUVIN 479 (BASF)).

[0055] Examples of benzotriazole-based UV absorbers include 2-(2H-benzotriazol-2-yl)-6-(1-methyl-1-phenylethyl)-4-(1,1,3,3-tetramethylbutyl)phenol (TINUVIN 928, manufactured by BASF) and 2-(2-hydroxy-5-tert-butylphenyl)-2H-benzotriazole (TINUVIN 928). PS (manufactured by BASF), benzenepropanoic acid and ester compound of 3-(2H-benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxy(C7-9 side chain and linear alkyl) (TINUVIN384-2, manufactured by BASF), 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol (TINUVIN900, manufactured by BASF), reaction product of methyl-3-(3-(2H-benzotriazol-2-yl)-5-t-butyl-4-hydroxyphenyl)propionate / polyethylene glycol 300 (TINUVIN1130, manufactured by BASF), 2-(2H-benzotriazol-2-yl)-p-cresol (TINUVIN P (BASF), 2(2H-benzotriazol-2-yl)-4-6-bis(1-methyl-1-phenylethyl)phenol (TINUVIN234, BASF), 2-[5-chloro(2H)-benzotriazol-2-yl]-4-methyl-6-(tert-butyl)phenol (TINUVIN326, BASF), 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol (TINUVIN328, BASF), 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol ( These are TINUVIN 329 (manufactured by BASF), the reaction product of methyl 3-(3-(2H-benzotriazol-2-yl)-5-tert-butyl-4-hydroxyphenyl)propionate and polyethylene glycol 300 (TINUVIN 213, manufactured by BASF), 2-(2H-benzotriazol-2-yl)-6-dodecyl-4-methylphenol (TINUVIN 571, manufactured by BASF), and 2-[2-hydroxy-3-(3,4,5,6-tetrahydrophthalimidomethyl)-5-methylphenyl]benzotriazole (Sumisorb 250, manufactured by Sumitomo Chemical Co., Ltd.).

[0056] The adhesive composition (I) may contain one or more ultraviolet absorbers (C).

[0057] <Additives> The adhesive composition (I) may contain other additives. Examples of additives include crosslinking agents, silane coupling agents, colorants such as pigments and dyes, surfactants, plasticizers, tackifiers, surface lubricants, leveling agents, rework improvers, softeners, antioxidants, anti-aging agents, light stabilizers, polymerization inhibitors, rust inhibitors, inorganic fillers, organic fillers, powders, particles, and foils such as metal powders. The rust inhibitor may be a benzotriazole type (e.g., BT120, BT-LX, TT-LX, etc., manufactured by Johoku Chemical Industry). Additives can be blended in an amount of, for example, 10 parts by weight or less, preferably 5 parts by weight or less, and more preferably 1 part by weight or less, per 100 parts by weight of the (meth)acrylic polymer (A).

[0058] Examples of crosslinking agents include organic crosslinking agents and polyfunctional metal chelates. Examples of organic crosslinking agents include isocyanate crosslinking agents, peroxide crosslinking agents, epoxy crosslinking agents, and imine crosslinking agents. Organic crosslinking agents and polyfunctional metal chelates can be used for both solvent-type and active energy ray-curing type adhesive compositions. When adhesive composition (I) is solvent-type, the crosslinking agent is preferably a peroxide-type crosslinking agent or an isocyanate-type crosslinking agent. Peroxide-type crosslinking agents and isocyanate-type crosslinking agents may be used in combination.

[0059] If the adhesive composition (I) contains a crosslinking agent, the amount of the crosslinking agent is, for example, 0.01 to 10 parts by weight, 0.1 to 5 parts by weight, or even 0.1 to 3 parts by weight, per 100 parts by weight of the (meth)acrylic polymer (A).

[0060] If the adhesive composition (I) contains a silane coupling agent, the amount of the silane coupling agent is, for example, 0.01 to 5 parts by weight or less per 100 parts by weight of the (meth)acrylic polymer (A), and may be 3 parts by weight or less, 1 part by weight or less, 0.5 parts by weight or less, 0.2 parts by weight or less, 0.1 parts by weight or less, or even 0.05 parts by weight or less. The adhesive composition (I) does not have to contain a silane coupling agent.

[0061] The adhesive composition (I) does not need to substantially contain a chromogenic compound whose maximum absorption wavelength in the absorption spectrum exceeds 380 nm. The maximum absorption wavelength of the chromogenic compound may be 385 nm or higher, 390 nm or higher, 395 nm or higher, 400 nm or higher, 410 nm or higher, or even 420 nm or higher. Substantially excluding a chromogenic compound having its maximum absorption wavelength in visible light can contribute to improving the color development performance of the OLED. The absorption spectrum of the chromogenic compound can be evaluated in the same way as the absorption spectrum of the ultraviolet absorber (C).

[0062] The type of adhesive composition (I) may be, for example, emulsion type, solvent type (solution type), active energy ray curing type (photocuring type), or thermal melt type (hot melt type). From the viewpoint of forming an adhesive sheet with superior uniformity of properties and durability, adhesive composition (I) may be of the solvent type. Photocuring adhesive compositions containing ultraviolet absorbers tend to exhibit variations in properties (e.g., peeling force) between the side on which the active energy ray is incident and the opposite side during photocuring. Solvent-type adhesive compositions (I) may not contain photocuring agents such as ultraviolet curing agents.

[0063] The adhesive sheet 1 can be formed from the adhesive composition (I) as follows.

[0064] For solvent-type adhesives, for example, an adhesive composition (I) or a mixture of adhesive composition (I) and a solvent is applied to a base film to form a coating film, and the formed coating film is dried to form an adhesive sheet 1. The adhesive composition (I) is heat-cured by the heat generated during drying. For active energy ray-cured (photocured) adhesives, for example, a mixture of monomers (group) that become (meth)acrylic polymers (A) by polymerization, and optionally partially polymerized monomers (group), polymerization initiators, additives, and solvents is applied to a base film, and an active energy ray is irradiated to form an adhesive sheet 1. The solvent may be removed by drying before irradiation with the active energy ray. The base film may be a film (separator film) with a release treatment applied to the coated surface.

[0065] The adhesive sheet 1 formed on the base film can be transferred to any material. The base film may also be an anti-reflective film 2, in which case an anti-reflective film 10 with an adhesive sheet, including the adhesive sheet 1 and the anti-reflective film 2, is obtained.

[0066] For coating the base film, known methods can be employed. Coating can be carried out by, for example, roll coating, kiss roll coating, gravure coating, reverse coating, roll brushing, spray coating, dip roll coating, bar coating, knife coating, air knife coating, curtain coating, lip coating, die coating, or other extrusion coating methods.

[0067] For solvent-based coatings, the drying temperature after application is, for example, 40 to 200°C. The drying temperature may also be 160°C or lower, 150°C or lower, 130°C or lower, 120°C or lower, or even 100°C or lower. The drying time may be, for example, 5 seconds to 20 minutes, 5 seconds to 10 minutes, or even 10 seconds to 5 minutes. For active energy ray-cured coatings, the drying temperature and drying time after application may be within the above ranges.

[0068] The composition and mixture to be applied to the base film preferably have a viscosity suitable for handling and coating. For this reason, in the case of active energy ray curing type, the mixture to be applied preferably contains partially polymerized monomers (groups).

[0069] In one example of a separator film, the coated surface is treated with a silicone compound for release.

[0070] The thickness of the adhesive sheet 1 is, for example, 1 to 200 μm, and may be 1 to 150 μm, 5 to 100 μm, 8 to 50 μm, 10 to 30 μm, or even 10 to 25 μm.

[0071] The adhesive sheet 1, when 20 μm thick, may have a transmittance (hereinafter referred to as T380) of less than 80% for light with a wavelength of 380 nm. The T380 of the 20 μm thick adhesive sheet 1 may be 75% or less, 70% or less, or even 65% or less. The lower limit of T380 may be, for example, 1% or more, or 5% or more.

[0072] The adhesive sheet 1 may have a substantially uniform curing state in the thickness direction. Having a substantially uniform curing state in the thickness direction is particularly suitable for use with OLEDs. A substantially uniform curing state can be confirmed, for example, by the fact that the peel force a of one main surface of the adhesive sheet 1 and the peel force b of the other main surface are substantially the same. The ratio a / b of peel force a to peel force b may be, for example, 0.5 or more and 2 or less, 0.67 or more and 1.5 or less, 0.75 or more and 1.33 or less, and even 0.91 or more and 1.1 or less. The peel force of the adhesive sheet 1 (main surface) may be, for example, the 180° peel force evaluated by the test method specified in Method 1 of Item 10.3 of Japanese Industrial Standard (JIS) Z0237:2009. Note that a glass plate may be used instead of a stainless steel plate as the test plate when performing this test method.

[0073] The adhesive sheet 1 may be a sheet formed from a solvent-type adhesive composition. An adhesive sheet formed from a solvent-type adhesive composition may have a substantially uniform curing state in the thickness direction. This can contribute, for example, to the stability of the OLED.

[0074] [Anti-reflective film] As shown in Figure 2, the anti-reflective film 2 has an anti-reflective layer 4 and further comprises, for example, a transparent resin film 3, a hard coat layer 6, an adhesion layer 5, and an anti-fouling layer 7. The anti-reflective film 2 does not necessarily have an adhesion layer 5, a hard coat layer 6, and an anti-fouling layer 7. In the anti-reflective film 2, for example, the transparent resin film 3, hard coat layer 6, adhesion layer 5, anti-reflective layer 4, and anti-fouling layer 7 are laminated in this order. The anti-reflective film 2 may have multiple anti-reflective layers 4, with the transparent resin film 3 positioned between the multiple anti-reflective layers 4. The anti-reflective film 2 may further have other layers, such as an anti-glare layer.

[0075] The adhesive sheet 1 is, for example, placed on the surface of the transparent resin film 3 and bonded to the transparent resin film 3. However, the adhesive sheet 1 may also be placed on the surface of the anti-reflective film 2 opposite to the transparent resin film 3, i.e., on the surface of the anti-reflective layer 4 or the anti-fouling layer 7.

[0076] (Anti-reflection layer) Examples of the configuration of the anti-reflective layer 4 include (i) a single layer of low refractive index layer having an optical film thickness of 120 nm to 140 nm and a refractive index of 1.35 to 1.50, (ii) a laminate in which a medium refractive index layer, a high refractive index layer, and a low refractive index layer are arranged in this order from the transparent resin film 3 side, and (iii) a multilayer laminate in which high refractive index layers and low refractive index layers are arranged alternately. Details of the laminate containing (ii) a medium refractive index layer, a high refractive index layer, and a low refractive index layer in this order are disclosed, for example, in Japanese Patent Application Publication No. 2018-173447. Details of the multilayer laminate in which high refractive index layers and low refractive index layers are arranged alternately are disclosed, for example, in Japanese Patent Application Publication No. 2017-227898. In the multilayer laminate, the total number of high refractive index layers and low refractive index layers is not particularly limited, and is, for example, 2 to 10.

[0077] Examples of materials that can form a low refractive index layer include silicon dioxide (SiO2) and magnesium fluoride (MgF2). The low refractive index layer is, for example, a layer having a refractive index of 1.35 to 1.50.

[0078] Examples of materials that can form a high refractive index layer include titanium oxide (TiO2), niobium oxide (Nb2O3 or Nb2O5), tin-doped indium oxide (ITO), antimond-doped tin oxide (ATO), and ZrO2-TiO2. The high refractive index layer is, for example, a layer having a refractive index greater than 1.80 and less than or equal to 2.20.

[0079] Examples of materials that can form a medium refractive index layer include titanium dioxide (TiO2) and mixtures of materials that can form a low refractive index layer and materials that can form a high refractive index layer (for example, a mixture of titanium dioxide and silicon dioxide). The medium refractive index layer is, for example, a layer having a refractive index greater than 1.50 and less than or equal to 1.80.

[0080] The thicknesses of the low refractive index layer, the medium refractive index layer, and the high refractive index layer can be set to achieve an appropriate optical film thickness depending on the layer structure of the anti-reflective layer 4, the desired anti-reflective performance, etc. The thickness of the anti-reflective layer 4 is not particularly limited and is, for example, 20 nm to 300 nm.

[0081] The anti-reflective layer 4 can be formed, for example, by a dry process. Specific examples of dry processes include PVD (Physical Vapor Deposition) and CVD (Chemical Vapor Deposition). PVD methods include vacuum deposition, reactive deposition, ion beam assisted deposition, sputtering, and ion plating. CVD methods include plasma CVD.

[0082] In the anti-reflective layer 4, the difference between the maximum reflectance and the minimum reflectance in the wavelength range of 380 nm to 780 nm is preferably 10% or less, more preferably 7% or less, and even more preferably 5% or less. When the difference between the maximum reflectance and the minimum reflectance is within the above range, it is easier to suppress the coloration of the reflected light.

[0083] (Transparent resin film) The transparent resin film 3 is not particularly limited, and any known film can be used. Preferred materials for the transparent resin film 3 are those with excellent transparency, mechanical strength, thermal stability, moisture barrier properties, and isotropy. Examples include polyester polymers such as polyethylene terephthalate and polyethylene naphthalate; cellulose polymers such as diacetylcellulose and triacetylcellulose (TAC); (meth)acrylic polymers such as polymethyl methacrylate; styrene polymers such as polystyrene and acrylonitrile-styrene copolymer (AS resin); polycarbonate polymers; polyolefin polymers such as polyethylene, polypropylene, cycloolefin polymers, polyolefins having a norbornene structure, and ethylene-propylene copolymer; vinyl chloride polymers; amide polymers such as nylon and aromatic polyamide; imide polymers; sulfone polymers; polyethersulfone polymers; polyetheretherketone polymers; polyphenylene sulfide polymers; vinyl alcohol polymers; vinylidene chloride polymers; vinyl butyral polymers; arylate polymers; polyoxymethylene polymers; epoxy polymers; and mixtures of these polymers. The transparent resin film 3 is preferably a TAC film.

[0084] The transparent resin film 3 may or may not contain an ultraviolet absorber. Examples of ultraviolet absorbers included in the transparent resin film 3 are those described above for ultraviolet absorber (C). The amount of ultraviolet absorber in the transparent resin film 3 is, for example, less than 20 parts by weight per 100 parts by weight of the main component (e.g., TAC) of the transparent resin film 3, and may be 15 parts by weight or less, 10 parts by weight or less, 8 parts by weight or less, or even 6 parts by weight or less. The lower limit of the amount is, for example, 0.1 parts by weight or more. The content of the main component in the transparent resin film 3 is, for example, 50% by weight or more, and may be 60% by weight or more, 70% by weight or more, 75% by weight or more, or even 80% by weight or more.

[0085] The thickness of the transparent resin film 3 is not particularly limited, but is preferably 3 to 200 μm from the viewpoint of strength, workability such as handling, and thinness, and is more preferably 5 to 150 μm, even more preferably 10 to 100 μm, and may also be 20 to 25 μm from the viewpoint of transparency and cost. Note that as the thickness of the transparent resin film 3 increases, the transmittance to light with a wavelength of 380 nm tends to decrease. From the viewpoint of reducing the transmittance to light with a wavelength of 380 nm, the thickness of the transparent resin film 3 may be 30 μm or more, or about 40 μm. The transparent resin film 3 may be a single layer or may be composed of multiple layers.

[0086] (Hard coat layer) The hard coat layer 6 is formed, for example, on the surface of the transparent resin film 3 on the side of the anti-reflective layer 4. The hard coat layer 6 tends to improve abrasion resistance and scratch resistance. Furthermore, by appropriately adjusting the difference between the refractive index of the hard coat layer 6 and the refractive index of the anti-reflective layer 4, the reflectivity can be further reduced.

[0087] The hard coat layer 6 preferably has sufficient surface hardness, excellent mechanical strength, and excellent light transmittance. The hard coat layer 6 can be formed from, for example, a resin that satisfies the above characteristics. Specific examples of resins for forming the hard coat layer 6 include thermosetting resins, thermoplastic resins, ultraviolet curing resins, electron beam curing resins, and two-component mixed resins. From the viewpoint of simple operation and efficient formation of the hard coat layer 6, ultraviolet curing resins are preferred.

[0088] Specific examples of UV-curable resins include polyester-based, acrylic-based, urethane-based, amide-based, silicone-based, and epoxy-based UV-curable resins. UV-curable resins include, for example, UV-curable monomers, oligomers, and polymers. UV-curable resins preferably contain acrylic monomer or oligomer components having two or more, preferably three to six, UV-polymerizable functional groups. UV-curable resins may contain, for example, photopolymerization initiators.

[0089] The hard coat layer 6 may further contain metal oxide particles in addition to the resin. The metal oxide particles may be exposed on the surface of the hard coat layer 6, particularly on the surface of the hard coat layer 6 on the side of the adhesion layer 5. Examples of materials for the metal oxide particles include oxides of at least one metal selected from the group consisting of Si, Al, Ti, Zr, Ce, Mg, Zn, Ta, Sb, Sn, and Mn.

[0090] The hard coat layer 6 can be formed, for example, by the following method. First, a resin composition for forming the hard coat layer 6 is applied to the transparent resin film 3 to obtain a coating film. The hard coat layer 6 can be formed by drying the coating film and then curing it by irradiation with ultraviolet light.

[0091] The thickness of the hard coat layer 6 is, for example, 0.5 μm to 20 μm, and preferably 1 μm to 15 μm.

[0092] (Intimate layer) The adhesion layer 5 can, for example, improve the adhesion between the hard coat layer 6 and the anti-reflective layer 4. In the anti-reflective film 2, the hard coat layer 6 contains metal oxide particles, and the adhesion layer 5 may contain the same metal as the metal oxide particles, or an oxygen-deficient metal oxide containing the same metal. Examples of the same metal as the metal oxide particles include the metals mentioned above for the hard coat layer 6. An oxygen-deficient metal oxide refers to a metal oxide in which the number of oxygen atoms is insufficient compared to the stoichiometric composition, specifically SiO x AlO x , TiO x , ZrO x CeO x MgO x ZnO x TaO x SbO x SnO x , MnO x Examples include (where x is greater than or equal to 0 and less than the stoichiometric amount). For example, if the metal oxide particles contained in the hard coat layer 6 are SiO2, then the SiO in the adhesion layer 5 x In this case, x is between 0 and 2.0 (inclusive).

[0093] The thickness of the adhesion layer is, for example, 10 nm or less, and preferably 1 to 10 nm.

[0094] Details regarding the hard coat layer 6 and the adhesion layer 5 are disclosed, for example, in Japanese Patent Publication No. 2016-224443.

[0095] (Anti-fouling layer) The antifouling layer 7 is provided, for example, on the surface of the anti-reflective layer 4. Examples of materials for the antifouling layer 7 include silane compounds containing fluorine groups (e.g., alkoxysilane compounds having perfluoropolyether groups) and organic compounds containing fluorine groups. It is preferable that the water contact angle exhibiting water repellency in the antifouling layer 7 is 110° or more.

[0096] (Method for manufacturing anti-reflective film) The anti-reflective film 2 can be manufactured, for example, by forming an anti-reflective layer 4 on a transparent resin film 3. Before forming the anti-reflective layer 4, the transparent resin film 3 may be subjected to surface treatment as needed. Examples of surface treatments include low-pressure plasma treatment, ultraviolet irradiation treatment, corona treatment, flame treatment, acid or alkali treatment, etc. On the surface of the transparent resin film 3, SiO x An adhesion layer 5 made of materials such as the above may be formed.

[0097] As described above, the antireflection layer 4 can be formed by a dry process (e.g., sputtering). For example, (ii) an antireflection layer 4 containing a medium refractive index layer, a high refractive index layer and a low refractive index layer in that order can be produced by sputtering, depositing the medium refractive index layer (e.g., antimond-doped tin oxide film), the high refractive index layer (e.g., Nb2O5 film) and the low refractive index layer (e.g., SiO2 film) in that order on the surface of the transparent resin film 3. For example, (iii) an antireflection layer 4 in which high refractive index layers and low refractive index layers are arranged alternately can be produced by sputtering, depositing the high refractive index layer (e.g., Nb2O5 film), the low refractive index layer (e.g., SiO2 film), the high refractive index layer (e.g., Nb2O5 film), and the low refractive index layer (e.g., SiO2 film) in that order on the surface of the transparent resin film 3.

[0098] (Characteristics of anti-reflective film) The anti-reflective film 2 may have anti-reflection (AR) function, anti-glare (AG) function, or both of these functions. If an anti-reflective film 2 with only the AR function is used, strong interference unevenness may occur. Therefore, it is preferable that the anti-reflective film 2 has both the AR function and the AG function. However, the anti-reflective film 2 may have only the AR function. An anti-reflective film 2 with only the AR function can be used in an image display device having a COE (Color filter On Encapsulation) structure. In an image display device having a COE structure, internal light emission is increased by a combination of a μ-cavity and a color filter, thereby suppressing the reflection of external light without using a polarizing plate.

[0099] [Other forms] Another example of the anti-reflective film with adhesive sheet according to this embodiment is shown in Figure 3. The anti-reflective film with adhesive sheet 10B in Figure 3 has the same structure as the anti-reflective film with adhesive sheet 10A in Figure 1, except that it further includes a separator 11 bonded to the adhesive sheet 1.

[0100] The separator 11 is typically a resin film. Examples of resins that make up the separator 11 include polyester such as polyethylene terephthalate (PET), polyolefins such as polyethylene and polypropylene, polycarbonate, acrylic, polystyrene, polyamide, and polyimide. The surface of the separator 11 that comes into contact with the adhesive sheet 1 may be treated with a release agent. The release agent is, for example, treated with a silicone compound. However, the separator 11 is not limited to the above examples. The separator 11 is peeled off when the anti-reflective film 10B with an adhesive sheet is used, for example, when it is attached to the image forming layer.

[0101] The anti-reflective film 10 with adhesive sheet of this embodiment can be distributed and stored, for example, as a wound body formed by winding a strip-shaped anti-reflective film with adhesive sheet, or as a single-sheet anti-reflective film with adhesive sheet.

[0102] The anti-reflective film 10 with adhesive sheet of this embodiment is typically used in image display devices. An example of an image display device is an OLED. However, the applications of the anti-reflective film 10 with adhesive sheet are not limited to the above example.

[0103] As described above, the anti-reflective film 10 with adhesive sheet of this embodiment does not include a polarizer. This configuration tends to suppress the decrease in brightness of the light emitted from the image display device and reduce the required power consumption.

[0104] The anti-reflective film 10 with adhesive sheet of this embodiment may have a transmittance (T380) of 5% or less for light with a wavelength of 380 nm. The T380 of the anti-reflective film 10 with adhesive sheet may be 4% or less, and even 3.5% or less. T380 is the transmittance of the anti-reflective film 10 with adhesive sheet in the lamination direction. The lower limit of the T380 of the anti-reflective film 10 with adhesive sheet is, for example, 0.01% or more.

[0105] [Image display device] An example of an image display device of this embodiment is shown in Figure 4. The image display device 21A in Figure 4 has a laminated structure in which a substrate 13, an image forming layer 12, an adhesive sheet 1, and an anti-reflective film 2 are laminated in this order. The image display device 21A has an anti-reflective film 10A with an adhesive sheet as shown in Figure 1. The image forming layer 12 and the substrate 13 may have the same configuration as the substrate and image forming layer of known image display devices. The image forming layer 12 is, for example, an organic EL light-emitting layer. The substrate 13 is typically a resin film. The resin constituting the substrate 13 is, for example, polyester such as PET, polyolefin such as polyethylene and polypropylene, acrylic, cycloolefin, polyimide, and polyamide, with polyester being preferred. However, the substrate 13 is not limited to the above example. The substrate 13 may be a glass film or a laminated film including a glass film. An undercoat layer may be provided on the surface of the substrate 13 facing the image forming layer 12. An antistatic layer may be provided on the surface of the substrate 13 opposite to the image forming layer 12. Known layers can be used for the undercoat layer and the antistatic layer. Any adhesive or bonding agent can be used to bond the image forming layer 12 to the substrate 13. An adhesive sheet 1 may also be used for bonding.

[0106] Another example of the image display device of this embodiment is shown in Figure 5. The image display device 21B in Figure 5 has the same configuration as the image display device 21A in Figure 4, except that it includes a touch panel 14 and a protective layer 15 between the image forming layer 12 and the adhesive sheet 1, in that order from the side of the image forming layer 12. Known layers can be applied to the touch panel 14 and the protective layer 15. The touch panel 14 typically includes a conductive layer such as a metal layer. The protective layer 15 is typically a resin layer such as an acrylic resin layer. Depending on its configuration, the adhesive sheet 1 is suitable for suppressing corrosion of the touch panel 14.

[0107] In the image display device of this embodiment, the adhesive sheet 1 and the anti-reflective film 10 with the adhesive sheet are usually located on the side closer to ambient light (the side closer to visibility) than the image forming layer 12.

[0108] The image display devices 21A and 21B may be OLEDs. The image display devices 21A and 21B may be for portable devices such as smartphones and smartwatches. The image display devices 21A and 21B may be flexible image display devices that can be bent. In particular, the image display devices 21A and 21B may be foldable image display devices that can be folded, or rollable image display devices that can be rolled up. However, the types of image display devices 21A and 21B are not limited to the above examples.

[0109] The image display device of this embodiment may have any configuration as long as it includes the anti-reflective film with adhesive sheet of this embodiment. The image display device of this embodiment does not need to have an antistatic layer on the side of the image forming layer 12 that is exposed to ambient light.

[0110] The image display device of this embodiment may include a transparent substrate (e.g., cover glass) and a transparent adhesive (OCA: Optical Clear Adhesive) on the side of the anti-reflective film 10 with adhesive sheet that is exposed to ambient light. The transparent adhesive is located between the transparent substrate and the anti-reflective film 10 with adhesive sheet, and joins them together. A commercially available product can be used as the transparent adhesive. The transparent adhesive may or may not contain an ultraviolet absorber. Examples of ultraviolet absorbers included in the transparent adhesive are those described above for ultraviolet absorber (C). The amount of ultraviolet absorber blended in the transparent adhesive is, for example, less than 20 parts by weight per 100 parts by weight of the main component of the transparent adhesive, and may be 15 parts by weight or less, 10 parts by weight or less, 8 parts by weight or less, and even 6 parts by weight or less. The lower limit of the blended amount is, for example, 0.1 parts by weight or more. The content of the main component in the transparent adhesive is, for example, 50% by weight or more, and may be 60% by weight or more, 70% by weight or more, 75% by weight or more, and even 80% by weight or more. [Examples]

[0111] The present invention will be described in more detail below with reference to examples. The present invention is not limited to the examples shown below.

[0112] The correspondence between the abbreviations or names shown in the following explanation and the compounds is as follows: BA: n-butyl acrylate AA: Acrylic acid HBA: 4-hydroxybutyl acrylate NVP: N-vinylpyrrolidone PEA: Phenoxyethyl acrylate MEA: Methoxyethyl acrylate ACMO: Acryloylmorpholin AIBN: 2,2'-Azobisisobutyronitrile LiTFSi: Lithium bis(trifluoromethanesulfonyl)imide AS110: 1-Ethyl-3-methylimidazolium bis(fluorosulfonyl)imide (manufactured by Daiichi Kogyo Seiyaku, Elexel AS-110) Tinosorb S: 2,4-bis-[{4-(4-ethylhexyloxy)-4-hydroxy}phenyl]-6-(4-methoxyphenyl)-1,3,5-triazine (manufactured by BASF Japan) Tinuvin 928: 2-(2H-benzotriazol-2-yl)-6-(1-methyl-1-phenylethyl)-4-(1,1,3,3-tetramethylbutyl)phenol (manufactured by BASF Japan) C / L: Trimethylolpropane / Tolylene diisocyanate trimer adduct (isocyanate-based crosslinking agent; manufactured by Tosoh Corporation, Coronate L) X-41-1810: Silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd.) X-41-1056: Silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd.)

[0113] [Preparation of (meth)acrylic polymer (A)] (Synthesis Example 1) 99.0 parts by weight of BA and 1.0 part by weight of HBA were placed in a four-necked flask equipped with a stirring blade, thermometer, nitrogen gas inlet tube, and condenser. Next, 0.1 parts by weight of AIBN was added to 100 parts by weight of the BA and HBA mixture as a polymerization initiator, and nitrogen gas was introduced while gently stirring to purge the flask with nitrogen. The polymerization reaction was then carried out for 7 hours while maintaining the liquid temperature in the flask at around 55°C. Next, ethyl acetate was added to the resulting reaction solution to adjust the solid content concentration to 12% by weight to obtain a solution of (meth)acrylic polymer (A-1).

[0114] (Synthesis examples 2-5) Solutions of (meth)acrylic polymers (A-2) to (A-5) were obtained in the same manner as in Synthesis Example 1, except that the monomers used and the amounts of those monomers used were as shown in Table 1 below.

[0115] The monomers and amounts used in synthesis examples 1-5 are summarized in Table 1 below.

[0116] [Table 1]

[0117] [Preparation of adhesive compositions and adhesive sheets] (Examples 1-14, Comparative Examples 1-3) As shown in Table 2 below, a solvent-type adhesive composition was obtained by mixing 100 parts by weight of solids of (meth)acrylic polymer (A) with an antistatic agent (B), an ultraviolet absorber (C), and a crosslinking agent. Tinosorb S (triazine-based), used as the ultraviolet absorber (C), has two hydroxyphenyl groups and one alkoxyphenyl group per molecule and exhibits an absorbance of 0.55 or higher in the maximum absorption wavelength range around 346 nm. Tinuvin928 (benzotriazole-based) exhibits broad absorption from 320 nm to 370 nm and exhibits an absorbance of 0.2 or higher in the maximum absorption wavelength range around 349 nm.

[0118] [Table 2]

[0119] Each prepared adhesive composition was applied to the release surface of a 38 μm thick PET film (Mitsubishi Chemical Polyester Films, MRF38), which is a separator film with a silicone treatment on its release surface, using a fountain coater. The film was then dried for 2 minutes in an air-circulating constant-temperature oven set to 155°C to form an adhesive sheet with a thickness of 20 μm. Next, another separator film was bonded to the exposed surface of the formed adhesive sheet to obtain an adhesive sheet sandwiched between a pair of separator films. The additional separator film was bonded so that its release surface and the adhesive sheet were in contact. The peeling forces a and b of the main surfaces of each prepared adhesive sheet were evaluated using the method described above, and all had a peeling force ratio a / b near 1.

[0120] The evaluation method for each adhesive sheet produced is shown below.

[0121] [Transmittance of light with a wavelength of 380nm (T380)] One separator film was peeled off, and the adhesive sheet was bonded to the surface of the glass plate. Next, the other separator film was peeled off, and the T380 in the thickness direction of the adhesive sheet was evaluated using an ultraviolet-visible light spectrophotometer (Otsuka Electronics, LPF-200). For the T380 evaluation, a correction was performed using the transmittance of the glass plate (in the thickness direction) for light at a wavelength of 380 nm, which had been measured in advance, as the baseline.

[0122] [Surface resistivity] After peeling off one of the separator films and leaving it indoors (temperature 25±5℃, relative humidity 50±10%) for 1 minute, the surface resistivity of the exposed surface was evaluated using a high-resistivity resistivity meter (Mitsubishi Chemical Analytec, HighResta MCP-HT450).

[0123] [Static Suppression Ability] The antistatic properties of the adhesive sheet were evaluated by fabricating an OLED using the adhesive sheet, as follows.

[0124] <Preparation of Antireflection Film> An SiO x adhesion layer (thickness: 10 nm) was formed by sputtering on the surface of a TAC film manufactured by Konica Minolta, Inc. (product name: KC2UA, thickness: 25 μm, containing an ultraviolet absorber). Further, an Nb₂O₅ film (high refractive index layer), a SiO₂ film (low refractive index layer), an Nb₂O₅ film (high refractive index layer) and a SiO₂ film (low refractive index layer) were sequentially formed on the adhesion layer, thereby forming an antireflection layer (optical thickness: 200 nm). Further, an antifouling layer (thickness: 10 nm) made of an alkoxysilane compound having a perfluoropolyether group was formed on the antireflection layer, to prepare an antireflection film.

[0125] <Preparation of Antireflection Film with Pressure-Sensitive Adhesive Sheet> Next, with respect to the obtained antireflection film, the prepared pressure-sensitive adhesive sheet was attached to the surface of the TAC film (the surface on the opposite side to the adhesion layer). Thus, an antireflection film with a pressure-sensitive adhesive sheet was prepared.

[0126] <Preparation of OLED> An organic EL light-emitting layer, the antireflection film with pressure-sensitive adhesive sheet, a transparent pressure-sensitive adhesive, and a cover glass (manufactured by Corning, Gorilla® Glass (0.7 t)) were laminated in this order to obtain an OLED for evaluation (the display portion is a rectangle of 70 mm long × 160 mm wide).

[0127] <Evaluation of Charge Suppression Ability> With a black image displayed on the display portion of the prepared OLED, the peripheral edge of the cover glass located at the outermost surface was continuously rubbed with a brass rod (cylindrical shape with a diameter of 7 to 8 mm) for 8 hours. The brass rod was repeatedly circulated around the peripheral edge of the cover glass at a speed of 100 mm / sec while applying a force of 100 gf. After 8 hours elapsed, the display portion of the OLED was visually observed. A case where green light emission was not observed was rated A (good), and a case where green light emission was observed was rated C (unacceptable).

[0128] [Ultraviolet Resistance Characteristics of OLED] Xenon arc testing was performed on the fabricated OLEDs, and the degradation of the white display brightness of the OLEDs before and after the test was visually confirmed. Ultraviolet light was irradiated from the cover glass side, which is located on the outermost surface. If no degradation of display brightness was observed before and after the test, it was designated as A; if degradation was observed, it was designated as C. The xenon arc test was performed using a benchtop xenon arc lamp accelerated lightfastness tester (ATLAS, SUNTEST XLS+) with a UV exposure dose of 95400 kJ / m². 2 It was implemented there.

[0129] [Corrosion prevention performance] The corrosion prevention performance of the adhesive sheet for touch panels was evaluated using the following method. An aluminum-deposited glass plate was prepared, simulating a touch panel, with a glass plate, an aluminum layer (0.4 μm thick), and an acrylic resin protective layer (2 μm thick) laminated in that order. Next, the anti-reflective film with the adhesive sheet prepared above was attached to the acrylic resin protective layer to obtain a test specimen for evaluation. Next, the test specimen was left in a heated and humidified atmosphere at a temperature of 65°C and a relative humidity of 95% for 336 hours. After returning the test specimen to an atmosphere at a temperature of 25°C and a relative humidity of 50%, it was placed on an illuminated backlight, and the corrosion state of the aluminum layer was visually checked to evaluate the corrosion prevention performance of the adhesive sheet. The anti-reflective film with the adhesive sheet was cut to a size of 3 cm x 3 cm for use. A (Good): No corrosion observed. B (Acceptable): Corrosion is present, but the maximum diameter of the corroded area is less than 1 mm. C (Not acceptable): Corroded areas with a maximum diameter of 1 mm or more are observed.

[0130] The evaluation results for each adhesive sheet produced are shown in Table 3 below.

[0131] [Table 3]

[0132] As shown in Table 3, 9 × 10 11In the anti-reflective film with adhesive sheet of the embodiment, which is equipped with an adhesive sheet having a surface resistivity of Ω / □ or less, high static charge suppression ability was ensured. [Industrial applicability]

[0133] The anti-reflective film with adhesive sheet of the present invention is suitable for use with OLEDs. [Explanation of Symbols]

[0134] 1 Adhesive sheet 2. Anti-reflective film 10A, 10B Anti-reflective film with adhesive sheet 21A,21B Image display device

Claims

1. An anti-reflective film with an adhesive sheet, comprising an adhesive sheet and an anti-reflective film, The aforementioned anti-reflective film with adhesive sheet does not contain a polarizer. The aforementioned adhesive sheet is 9 x 10 11 Having a surface resistivity of Ω / □ or less, The aforementioned adhesive sheet is a sheet formed from an adhesive composition containing a (meth)acrylic polymer and an organic crosslinking agent. The anti-reflective film includes a multilayer laminate in which a high refractive index layer and a low refractive index layer are laminated. Anti-reflective film with adhesive backing.

2. The anti-reflective film with an adhesive sheet according to claim 1, wherein the adhesive sheet is disposed on the surface of the anti-reflective film.

3. The anti-reflective film with adhesive sheet according to claim 1 or 2, wherein the adhesive composition is solvent-based.

4. The adhesive sheet comprises an antistatic agent, and the antireflective film with an adhesive sheet is as described in any one of claims 1 to 3.

5. An anti-reflective film with an adhesive sheet according to any one of claims 1 to 4, for use in an organic electroluminescent display device.

6. An image display device comprising an anti-reflective film with an adhesive sheet as described in any one of claims 1 to 5.

7. The image display device according to claim 6, wherein the image display device is an organic electroluminescent display device.

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