TW202239902A - Optical laminate, image display device, and adhesive composition - Google Patents

Abstract

The provided optical laminate includes an optical base material and an adhesive layer disposed on the surface of the optical base material. The adhesive layer contains an adhesive composition containing a silane coupling agent. The silane coupling agent contains an isocyanuric ring and does not contain an isocyanate group. The surface on which the adhesive layer is disposed is a modified surface that has been subjected to surface modification by energy irradiation. The optical laminate has excellent high-temperature peel resistance.

Description

Optical laminate, image display device and adhesive composition

The invention relates to an optical laminate, an image display device and an adhesive composition.

Various thin image display devices such as liquid crystal displays and organic EL displays generally include an optical layered body, and the optical layered body includes an optical base material and an adhesive layer arranged on the surface of the optical base material. Examples of optical substrates are image forming layers such as liquid crystal layers and organic EL light emitting layers, optical films such as polarizing plates and retardation films, and cover windows. The adhesive layer is used to join the layers contained in the optical laminate. In addition, in an optical substrate composed of multiple layers, for example, a polarizing plate composed of a polarizer and a polarizer protective film, the multiple layers may be bonded via an adhesive layer.

Patent Document 1 discloses an optical laminate consisting of a light-transmitting adherend, an adhesive layer containing a specific silane coupling agent, and a polarizing plate, and the specific silane coupling agent has an epoxy group at one end . Patent Document 1 describes that the adhesion of the adhesive layer to the glass plate can be improved by including the above-mentioned silane coupling agent. prior art literature patent documents

Patent Document 1: Japanese Patent Laid-Open No. 7-20314

The problem to be solved by the invention Image display devices may be exposed to high temperatures. Therefore, the optical layered body is required to be resistant to peeling between the layers bonded through the adhesive layer even at high temperature, in other words, to have excellent peeling resistance at high temperature. In addition, image display devices often use optical substrates other than glass substrates in order to reduce weight and improve functionality. Therefore, it is required that peeling between optical substrates other than glass substrates is also difficult to occur. However, according to the study of the inventors of the present invention, the optical layered body of Patent Document 1 cannot sufficiently cope.

An object of the present invention is to provide an optical layered body excellent in peeling resistance at high temperature.

means to solve problems The present invention provides an optical laminate, comprising an optical substrate and an adhesive layer disposed on the surface of the optical substrate; The aforementioned adhesive layer comprises an adhesive composition containing a silane coupling agent; The aforementioned silane coupling agent contains an isocyanuric acid ring and does not contain an isocyanate group; The above-mentioned surface on which the above-mentioned adhesive layer is disposed is a modified surface whose surface is modified by irradiating energy.

In another aspect, the present invention provides an image display device comprising the above-mentioned optical layered body of the present invention and an image forming layer.

In another aspect, the present invention provides an adhesive composition for use on the surface of an optical substrate; The adhesive composition comprises a silane coupling agent; The aforementioned silane coupling agent contains an isocyanuric acid ring and does not contain an isocyanate group; The aforementioned surface on which the aforementioned adhesive composition can be placed is a modified surface modified by irradiating energy.

Invention effect According to the present invention, it is possible to provide an optical laminate excellent in peeling resistance at high temperature.

Embodiments of the present invention will be described below with reference to the drawings. The present invention is not limited by the following embodiments.

[Optical laminate] The optical layered body of this embodiment is shown in FIG. 1. The optical laminate 100 in FIG. 1 has an optical substrate 1 and an adhesive layer 2 . The adhesive layer 2 is disposed on the surface 11 of the optical substrate 1 . The adhesive layer 2 and the optical substrate 1 are in contact with each other. The surface 11 disposed with the adhesive layer 2 is a modified surface 12 that is modified by irradiation of energy. The adhesive layer 2 includes an adhesive composition containing a silane coupling agent (hereinafter referred to as “Si agent (X)”) which contains an isocyanuric acid ring but does not contain an isocyanate group. The isocyanuric acid ring has a structure represented by the following formula (1). Molecular structure (Y) including Si atom and hydrolyzable group is bonded to at least one * (bonding site) in formula (1). Molecular structure (Y) may be bonded to 2* or all 3*. * in the unbonded molecular structure (Y) is not particularly limited, and may be bonded to a hydrogen atom, a halogen atom, or an organic residue.

[chemical formula 1]

We believe that the inclusion of Si agent (X) helps to maintain the cohesion of the adhesive layer 2 at high temperatures (such as 50-100°C, typically 80°C), and to improve the modification of the optical substrate 1 at high temperatures Adhesion of surface 12. Maintaining the cohesion, in other words, suppressing the cohesion failure of the adhesive layer 2 and improving the adhesion will improve the peeling resistance at high temperature. We speculate that the above contributions will play the following roles: (1) Especially when the plurality of * of the isocyanuric acid ring is bonded with a molecular structure (Y), a covalent bond with the modified surface 12 can be formed in the adhesive layer 2. The distribution of the bonded molecular structure (Y) can become more uniform; (II) the NCO structure that can form a hydrogen bond with the modified surface 12 expands equally in three directions in the isocyanuric acid ring; And (III) the NCO structure of the isocyanuric acid ring is different from the isocyanate group, and it is not easy to form bonds with other materials that may be contained in the adhesive layer 2, such as polymers or crosslinking agents, so that the adhesive layer can be improved. 2. The uniformity of the cross-linked structure. In addition, according to the study of the inventors of the present application, the cohesion of the adhesive layer 2 can be evaluated by using the 800% modulus.

In addition, the Si agent (X) can exist in a relatively large amount in the region 21 near the interface 3 with the optical substrate 1 in the adhesive layer 2 . Partially stored in the region 21 can enhance the adhesion to the modified surface 12 at high temperature. In view of the above aspects, the Si agent (X) can also be localized in the region 21 near the interface 3 with the optical substrate 1 in the adhesive layer 2 . The region 21 near the interface 3 refers to, for example, a region that accounts for 20% of the thickness of the adhesive layer 2 in the direction from the interface 3 to the thickness of the adhesive layer 2 . The distribution of the Si agent (X) in the adhesive layer 2 can be confirmed, for example, by an evaluation method capable of elemental analysis in the thickness direction of the layer, such as time-of-flight secondary ion mass spectrometry (TOF-SIMS) of etching ions. Offset can be confirmed, for example, by means of a plot obtained by TOF-SIMS, in which the horizontal axis is the etching time (corresponding to the thickness direction of the adhesive layer 2) and the vertical axis is the intensity of SiOH ⁺ (m/z=45) . In the adhesive layer 2 in which the Si agent (X) is partially distributed, the area sum of the SiOH ⁺ peaks in the region 21 may be 50% or more of the area sum of the SiOH ⁺ peaks that can be measured in the adhesive layer 2, or may be 60% or more , more than 70%, more than 80%, more than 90%. In addition, the intensity of SiOH ⁺ may be a value (normalized intensity) normalized by the ion intensity generated in large quantities from the adhesive layer 2 and whose m/z does not overlap with SiOH ⁺ at the time of TOF-SIMS evaluation. When the adhesive layer 2 contains an acrylic adhesive composition, the ion is, for example, C ₂ H ₃ ⁺ .

In the example of FIG. 1 , the adhesive layer 2 is disposed on the entire surface 11 of the optical substrate 1 . When viewed perpendicularly to the surface 11, the optical substrate 1 and the adhesive layer 2 have the same shape. However, it is sufficient if the adhesive layer 12 is disposed on at least a part of the surface 11 . In addition, the entirety of the surface 11 in FIG. 1 is the modified surface 12 . However, at least a part of the surface 11 may be the modified surface 12 .

[Si agent (X)] The Si agent (X) contains an isocyanuric acid ring. The number of isocyanuric acid rings contained in the Si agent (X) may be 1 or more, or may be 1. In the Si agent (X), the number of Si atoms per isocyanuric acid ring may be 1, may be greater than 1, may be 2 or more, and may be 3 or more. The number of Si atoms contained in one molecular structure (Y) is not limited, and is typically one.

A molecular structure containing a hydrolyzable group may also be bonded to the Si atom of the Si agent (X). The hydrolyzable group is, for example, an alkoxy group having 1 to 4 carbon atoms, which may be methoxy, ethoxy, or methoxy. The hydrolyzable group may be directly bonded to the Si atom.

The Si agent (X) does not contain an isocyanate group. The Si agent (X) may not contain a reactive functional group other than an isocyanate group, and particularly may not contain a reactive functional group other than an isocyanate group at a terminal. However, the reactive functional groups do not include hydrolyzable groups and isocyanuric acid rings bonded to Si atoms. Examples of reactive functional groups are epoxy, amine, vinyl, styryl, (meth)acryl, ureido, mercapto, especially epoxy, amine, and epoxy. Compared with isocyanate groups, these groups are less reactive with other materials that the adhesive layer 2 may contain. However, the absence of reactive functional groups helps to improve the uniformity of the crosslinked structure of the adhesive layer 2 . In addition, the amine group easily reacts with materials other than polymers, such as crosslinking agents.

An example of the Si agent (X) is shown in the following formula (2). The Si agent (X) of the formula (2) is ginseng-(trialkoxysilyl alkyl) isocyanurate. R ¹ , R ² and R ³ in formula (2) are independently an alkylene group with 1 to 6 carbons, may be an alkyl group with 2 to 4 carbons, or may be a propyl group. R ¹¹ , R ¹² , R ¹³ , R ²¹ , R ²² , R ²³ , R ³¹ , R ³² and R ³³ are independently an alkoxy group with 1 to 4 carbons, which may be methoxy or ethoxy, or May be methoxy.

[chemical formula 2]

[Adhesive composition] The content of the Si agent (X) in the adhesive composition contained in the adhesive layer 2 is, for example, 0.01% by weight to 5.0% by weight, or may be 0.01% by weight to 3.0% by weight, or 0.05% by weight or more. 1.0% by weight or less, 0.1% by weight or more and 0.5% by weight or less, more preferably 0.15% by weight or more and 0.4% by weight or less. Appropriate control of the content helps to improve the peeling resistance at high temperature more reliably.

The adhesive composition includes, for example, a (meth)acrylic polymer. The (meth)acrylic polymer can be the main component of the adhesive composition, in other words, the adhesive composition can also be acrylic. The acrylic adhesive composition is excellent in various properties such as transparency, processability, durability, and adhesion. However, the adhesive composition is not limited to acrylic. In this specification, (meth)acrylic acid means acrylic acid and/or methacrylic acid. Also, the main component means the component with the largest content in the composition. The content of the main component is, for example, 50% by weight or more, may be 70% by weight or more, 80% by weight or more, 90% by weight or more, 95% by weight or more, 97% by weight or more, 98% by weight or more, and may be 99% by weight above.

The adhesive composition may also contain one or more than two (meth)acrylic polymers.

＜(Meth)acrylic polymer＞ The (meth)acrylic polymer may have a unit (a2) derived from a (meth)acrylic monomer (a1) having an alkyl group having 1 to 30 carbon atoms in the side chain, or may have the unit (a2) as the main unit. The alkyl group may be linear or branched. A (meth)acrylic polymer may have 1 type, or 2 or more types of units (a2).

Examples of the monomer (a1) are: methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, secondary butyl (meth)acrylate, tri-butyl (meth)acrylate Grade butyl ester, isobutyl (meth)acrylate, n-pentyl (meth)acrylate, isoamyl (meth)acrylate, n-hexyl (meth)acrylate, isohexyl (meth)acrylate, (meth) ) isoheptyl acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, n-nonyl (meth)acrylate, (meth)acrylic acid Isononyl, n-decyl (meth)acrylate, isodecyl (meth)acrylate, n-dodecyl (meth)acrylate (lauryl (meth)acrylate), n-tridecyl (meth)acrylate and tetradecyl (meth)acrylate. In this specification, the "main unit" means, for example, a unit accounting for more than 50% by weight, preferably more than 80% by weight, more preferably more than 90% by weight, of the total structural units of the polymer, and more preferably It is preferably a unit accounting for 94% by weight or more. The upper limit of the ratio of the main unit is, for example, 99.9% by weight or less, and may be 99.5% by weight or less.

A (meth)acrylic polymer may have the unit (a2) derived from the monomer (a1) which has a long-chain alkyl group in a side chain. The monomer (a1) is, for example, n-dodecyl (meth)acrylate. In this specification, a long-chain alkyl group means an alkyl group having 6 to 30 carbon atoms.

When a (meth)acrylic polymer is a homopolymer, it may have the unit (a2) derived from the monomer (a1) whose Tg exists in -70 degreeC - -20 degreeC. The monomer (a1) is, for example, 2-ethylhexyl acrylate.

The (meth)acrylic polymer may have units other than the unit (a2). This unit is, for example, a unit (b2) derived from a monomer (b1) copolymerizable with the monomer (a1). A (meth)acrylic polymer may have 1 type, or 2 or more types of units (b2).

An example of the monomer (b1) is a (meth)acrylic monomer (c1) having a hydroxyl group. The monomer (b1) may also be a hydroxyl-containing (meth)acrylate monomer. Examples of monomers (c1) are: 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyl (meth)acrylate Hydroxyalkyl (meth)acrylates such as hexyl ester, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate and 12-hydroxylauryl (meth)acrylate, and (4- Hydroxymethylcyclohexyl)-methacrylate. In view of improving the durability of the adhesive composition, the monomer (c1) can also be 2-hydroxyethyl (meth)acrylate or 4-hydroxybutyl (meth)acrylate.

The monomer (b1) may also be an amino group-containing monomer or an amide group-containing monomer. Examples of amino group-containing monomers include N,N-dimethylaminoethyl (meth)acrylate and N,N-dimethylaminopropyl (meth)acrylate. Examples of amide-containing monomers are: (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(methyl)acrylamide ) acrylamide, N-methylol-N-propane(meth)acrylamide, aminomethyl(meth)acrylamide, aminoethyl(meth)acrylamide, mercaptomethyl(methyl)acrylamide ) acrylamide and mercaptoethyl (meth)acrylamide and other acrylamide-based monomers; N-acryl heterocyclic monomers such as (meth)acrylpyrrolidine; body etc.

The monomer (b1) may also be a carboxyl 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, crotonic acid. However, the unit derived from a carboxyl group-containing monomer has a strong effect of increasing the modulus of elasticity of the adhesive layer 2, and there is freedom in designing the physical properties of the adhesive layer 2 including the (meth)acrylic polymer having the unit. tendency to decrease. Moreover, the (meth)acrylic polymer which has this unit can have corrosion resistance to an optical base material by the material contained in an optical base material. From this point of view, the content of the carboxyl group-containing monomer-derived unit in the (meth)acrylic polymer is preferably 5% by weight or less, and may be 3% by weight or less, 1.5% by weight or less, 1% by weight or less, 0.5% by weight or less, more preferably 0% by weight (excluding this unit).

The monomer (b1) may also be a polyfunctional monomer. By using multifunctional monomers, the gel fraction of the adhesive composition can be adjusted. Examples of polyfunctional monomers are: 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, Neopentyl Glycol Di(meth)acrylate, Neopentyl tetra Alcohol tri(meth)acrylate, Dineopentaerythritol hexa(meth)acrylate, Trimethylolpropane tri(meth)acrylate, Tetramethylolmethane tri(meth)acrylate, (Meth ) polyfunctional acrylates such as allyl acrylate, vinyl (meth)acrylate, epoxy acrylate, polyester acrylate and urethane acrylate; and divinylbenzene. The multifunctional acrylate is preferably 1,6-hexanediol diacrylate and dipenteoerythritol hexa(meth)acrylate.

Examples of other monomers (b1) other than the above are: 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate , 3-methoxypropyl (meth)acrylate, 3-ethoxypropyl (meth)acrylate, 4-methoxybutyl (meth)acrylate and 4-ethoxybutyl (meth)acrylate, etc. ( Alkoxyalkyl methacrylate; Epoxy-containing monomers such as glycidyl (meth)acrylate and methylglycidyl (meth)acrylate; sodium vinylsulfonate and other sulfonic acid groups Monomers; monomers containing phosphoric acid groups; cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate and isocamphoryl (meth)acrylate and other (meth)acrylates with alicyclic hydrocarbon groups; ( (meth)acrylates with aromatic hydrocarbon groups such as phenyl methacrylate, phenoxyethyl (meth)acrylate and benzyl (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.

Content rate of units derived from (meth)acrylic monomer (c1) having a hydroxyl group, amine group-containing monomer, amide group-containing monomer, and polyfunctional monomer in (meth)acrylic polymer The total of is, for example, 20% by weight or less, may be 10% by weight or less, 8% by weight or less, and may be 5% by weight or less. When the (meth)acrylic polymer has the unit, the total content of the unit may be, for example, 0.01% by weight or more, or may be 0.05% by weight or more.

The total content of the unit (b2) derived from the monomer (b1) in the (meth)acrylic polymer is, for example, 30% by weight or less, may be 10% by weight or less, or may be 0% by weight (excluding this unit).

The (meth)acrylic polymer can be formed by polymerizing a monomer group including the above-mentioned monomers by a known method. It is also possible to polymerize monomers and partial polymers of monomers. Polymerization can be implemented by, for example, solution polymerization, emulsion polymerization, bulk polymerization, thermal polymerization, or active energy ray polymerization. In view of the fact that an adhesive composition with excellent optical transparency can be formed, the polymerization is preferably solution polymerization or active energy ray polymerization. Polymerization should be carried out by avoiding contact of monomer and/or part of the polymer with oxygen. Therefore, for example, polymerization in an inert gas environment such as nitrogen, or polymerization in a state where oxygen is blocked by a resin film or the like can be used. The formed (meth)acrylic polymer may be in any form of random copolymer, block copolymer, graft copolymer, etc., and may also be a random copolymer.

The polymerization system for forming a (meth)acrylic polymer may also contain one or two or more polymerization initiators. The type of polymerization initiator can be selected according to the polymerization reaction, for example, it can be a photopolymerization initiator or a thermal polymerization initiator.

Solvents used in solution polymerization are, 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; cyclohexane and methylcyclohexane Alicyclic hydrocarbons such as methyl ethyl ketone, methyl isobutyl ketone and other ketones. However, the solvent is not limited to the above examples. The solvent may be a mixed solvent of two or more solvents.

The polymerization initiator used for the solution polymerization is, for example, an azo-type polymerization initiator, a peroxide-type polymerization initiator, or a redox-type polymerization initiator. Peroxide-based polymerization initiators are, for example, dibenzoyl peroxide and tertiary butyl peroxymaleate. Among them, the azo-based polymerization initiator disclosed in Japanese Patent Application Laid-Open No. 2002-69411 is preferred. The azo-based polymerization initiator is, for example, 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis-2-methylbutyronitrile, 2,2'-azobis(2 -dimethylpropionate), 4,4'-azobis-4-cyanovaleric acid. However, the polymerization initiator is not limited to the above examples. The usage-amount of an azo type polymerization initiator is 0.05-0.5 weight part with respect to 100 weight part of total monomers, for example, and may be 0.1-0.3 weight part.

The active energy rays used for active energy ray polymerization are, for example, alpha rays, beta rays, gamma rays, neutron rays, ionizing radiation rays such as electron beams, and ultraviolet rays. The active energy rays are preferably ultraviolet rays. Polymerization by ultraviolet irradiation is also called photopolymerization. The polymerization system of active energy ray polymerization typically includes a photopolymerization initiator. The polymerization conditions of the active energy polymerization are not limited as long as a (meth)acrylic polymer can be formed.

系光聚合引發劑。惟，光聚合引發劑不受上述例所限。The photopolymerization initiator is, for example, a benzoin ether photopolymerization initiator, an acetophenone photopolymerization initiator, an α-ketol alcohol photopolymerization initiator, an aromatic sulfonyl chloride photopolymerization initiator, a photoactive oxime Photopolymerization initiator, benzoin photopolymerization initiator, benzyl photopolymerization initiator, benzophenone photopolymerization initiator, ketal photopolymerization initiator, 9-oxosulfur

Department of photopolymerization initiator. However, the photopolymerization initiator is not limited to the above examples.

系光聚合引發劑例如為：9-氧硫𠮿

、2-氯9-氧硫𠮿

、2-甲基9-氧硫𠮿

、2,4-二甲基9-氧硫𠮿

、異丙基9-氧硫𠮿

、2,4-二異丙基9-氧硫𠮿

、十二烷基9-氧硫𠮿

。Benzoin ether-based photopolymerization initiators are, for example: benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy Base-1,2-diphenylethan-1-one, anisole methyl ether. Acetophenone-based photopolymerization initiators are, for example: 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexyl phenyl ketone, 4 -Phenoxydichloroacetophenone, 4-(tertiary butyl)dichloroacetophenone. The α-ketol-based photopolymerization initiators include, for example, 2-methyl-2-hydroxypropiophenone and 1-[4-(2-hydroxyethyl)benzene]-2-methylpropan-1-one. The aromatic sulfonyl chloride photopolymerization initiator is, for example, 2-naphthalenesulfonyl chloride. The photoactive oxime-based photopolymerization initiator is, for example, 1-benzene-1,1-propanedione-2-(o-ethoxycarbonyl)-oxime. The benzoin-based photopolymerization initiator is, for example, benzoin. The benzyl group photopolymerization initiator is, for example, benzyl group. Benzophenone-based photopolymerization initiators are, for example, diphenyl ketone, benzoylbenzoic acid, 3,3'-dimethyl-4-methoxydiphenyl ketone, polyvinyl diphenyl ketone, α - Hydroxycyclohexyl phenyl ketone. The ketal photopolymerization initiator is, for example, benzyl dimethyl ketal. 9-oxosulfur

A photopolymerization initiator such as: 9-oxosulfur 𠮿

, 2-Chloro9-oxosulfur 𠮿

, 2-methyl 9-oxosulfur 𠮿

, 2,4-Dimethyl 9-oxosulfur 𠮿

, Isopropyl 9-oxosulfur

, 2,4-Diisopropyl 9-oxosulfur 𠮿

, dodecyl 9-oxosulfur 𠮿

.

The usage-amount of a photoinitiator is 0.01-1 weight part with respect to 100 weight part of total monomers, for example, and may be 0.05-0.5 weight part.

In addition, the polyfunctional monomer (polyfunctional acrylate, etc.) of the monomer (b1) can also be used in any adhesive composition of a solvent type or an active energy ray hardening type. When using both a polyfunctional monomer and a photopolymerization initiator for a solvent-based adhesive composition, the adhesive composition may be cured by irradiating active energy rays after removing the solvent by, for example, thermal drying.

The weight average molecular weight (Mw) of a (meth)acrylic-type polymer is 1 million or more, for example, 1.2 million or more, 1.5 million or more, 1.8 million or more, and 2 million or more. The upper limit of Mw is, for example, 3 million or less.

The molecular weight distribution (Mw/number average molecular weight (Mn)) of a (meth)acrylic-type polymer is 2-20, for example, and 4-15 may be sufficient. In addition, the Mw and Mn of a polymer and an oligomer in this specification are the values measured by GPC (gel permeation chromatography; Gel Permeation Chromatography) (in terms of polystyrene).

The content of the (meth)acrylic polymer in the adhesive composition is, for example, 50% by weight or more, 60% by weight or more, or even 70% by weight or more in terms of solid content.

＜(Meth)acrylic oligomer＞ The adhesive composition may further include a (meth)acrylic oligomer.

The (meth)acrylic oligomer may have the same composition as the above-mentioned (meth)acrylic polymer except that Mw is different. Mw of the (meth)acrylic oligomer is, for example, 1000 or more, may be 2000 or more, 3000 or more, and may be 4000 or more. The upper limit of Mw of the (meth)acrylic oligomer is, for example, 30,000 or less, may be 15,000 or less, 10,000 or less, and may be 7,000 or less.

(Meth)acrylic oligomers have, for example, one or more constituent units derived from the following monomers: methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate , Isopropyl (meth)acrylate, Butyl (meth)acrylate, Isobutyl (meth)acrylate, Secondary butyl (meth)acrylate, Tertiary butyl (meth)acrylate, (Meth) ) pentyl acrylate, isoamyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, Isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate Alkyl (meth)acrylates such as lauryl (meth)acrylate and lauryl (meth)acrylate; Esters of (meth)acrylic acid and alicyclic alcohols; aryl (meth)acrylates such as phenyl (meth)acrylate and benzyl (meth)acrylate; base) acrylate.

The (meth)acrylic oligomer may have a structural unit derived from an acrylic monomer having a relatively large volume structure. Examples of the acrylic monomers are: (meth)acrylic acid alkyl esters with branched alkyl groups such as isobutyl (meth)acrylate and tertiary butyl (meth)acrylate; Esters of (meth)acrylic acid and alicyclic alcohols such as cyclohexyl acrylate, isobornyl (meth)acrylate and dicyclopentanyl (meth)acrylate; phenyl (meth)acrylate and (meth)acrylic acid Aryl (meth)acrylate such as benzyl ester. The acrylic monomer preferably has a cyclic structure, and preferably has two or more cyclic structures. In addition, if the (meth)acrylic oligomer is to be irradiated with ultraviolet light when it is polymerized and/or when forming an adhesive composition, the acrylic monopolymer is less likely to hinder the polymerization and/or formation The body preferably has no unsaturated bond, for example, alkyl (meth)acrylate having an alkyl group with a branched chain structure, ester of (meth)acrylic acid and alicyclic alcohol can be used.

Specific examples of (meth)acrylic oligomers are: copolymers of butyl acrylate, methyl acrylate and acrylic acid, copolymers of cyclohexyl methacrylate and isobutyl methacrylate, cyclohexyl methacrylate Copolymer with isocamphoryl methacrylate, copolymer of cyclohexyl methacrylate and acrylmorphin, copolymer of cyclohexyl methacrylate and diethylacrylamide, 1-adamantyl acrylate Copolymer of ester and methyl methacrylate, copolymer of dicyclopentyl methacrylate and isobornyl methacrylate, selected from dicyclopentanyl methacrylate, cyclohexyl methacrylate, isobornyl methacrylate Copolymer of camphenyl, isocamphoryl acrylate, and cyclopentyl methacrylate with methyl methacrylate, homopolymer of dicyclopentyl acrylate, homopolymer of 1-adamantyl methacrylate Polymer, homopolymer of 1-adamantyl acrylate.

As the polymerization method of the (meth)acrylic oligomer, the above-mentioned polymerization method of the (meth)acrylic polymer can be used.

When the adhesive composition contains a (meth)acrylic oligomer, the blending amount thereof is, for example, 70 parts by weight or less, 50 parts by weight or less, and more preferably 100 parts by weight of the (meth)acrylic polymer. 40 parts by weight or less. The lower limit of the compounding quantity is 0.05 weight part or more with respect to 100 weight part of (meth)acrylic-type polymers, for example, 0.1 weight part or more may be sufficient as 0.2 weight part or more. The adhesive composition may not contain a (meth)acrylic oligomer.

The (meth)acrylic oligomer can also be used in any type of adhesive composition of solvent type and active energy ray curing type. However, when the (meth)acrylic oligomer is dissolved in a solvent when used in an active energy ray-curable adhesive composition, the mixture mixed with the (meth)acrylic oligomer is, for example, heated After drying to remove the solvent, the curing may proceed by irradiating active energy rays.

＜Crosslinking agent＞ The adhesive composition may further include a crosslinking agent. By using a cross-linking agent, the cohesion of the adhesive composition can be improved.

Examples of crosslinking agents are organic crosslinking agents and polyfunctional metal chelate compounds. Examples of organic crosslinking agents are isocyanate crosslinking agents, peroxide crosslinking agents, epoxy crosslinking agents and imine crosslinking agents. The polyfunctional metal chelate has a structure in which polyvalent metals and organic compounds are covalently bonded or coordinately bonded. The polyvalent metal is, for example, Al, Cr, Zr, Co, Cu, Fe, Ni, V, Zn, In, Ca, Mg, Mn, Y, Ce, Sr, Ba, Mo, La, Sn, Ti. The atom in an organic compound in which the polyvalent metal can be covalently or coordinately bonded is typically an oxygen atom. Examples of organic compounds are alkyl esters, alcohol compounds, carboxylic acid compounds, ether compounds and ketone compounds. In addition, organic cross-linking agents and polyfunctional metal chelates can also be used for any type of adhesive composition of solvent type and active energy ray curing type.

When the adhesive composition is solvent-based, the cross-linking agent is preferably an isocyanate-based cross-linking agent or a peroxide-based cross-linking agent. The isocyanate-based crosslinking agent may be difunctional or trifunctional. However, in order to maintain the cohesive force at high temperature, it is suitable to be a trifunctional crosslinking agent. According to the trifunctional cross-linking agent, a three-dimensional cross-linking structure will be formed. Moreover, an isocyanate type crosslinking agent and a peroxide type crosslinking agent can also be used together. By using them in combination, the adhesive force can be further improved while maintaining the cohesive force at high temperature. The isocyanate-based crosslinking agent used in combination is preferably trifunctional.

When the adhesive composition contains a cross-linking agent, its blending amount is, for example, 0.01-10 parts by weight, 0.1-5 parts by weight, or 0.1-3 parts by weight relative to 100 parts by weight of the (meth)acrylic polymer. parts by weight.

When the isocyanate-based crosslinking agent is used alone, its blending amount is 0.01-3 parts by weight, for example, 0.01-1 part by weight, 0.01-0.5 parts by weight, or more, relative to 100 parts by weight of the (meth)acrylic polymer. It may be 0.01 to 0.3 parts by weight.

When an isocyanate-based crosslinking agent and a peroxide-based crosslinking agent are used together, the weight ratio of the peroxide-based crosslinking agent to the isocyanate-based crosslinking agent is, for example, 1.0 or more, may be 1.2 or more, 1.5 or more, and may be 2 or more. above. Moreover, the upper limit of weight ratio is 500 or less, for example, may be 300 or less, and may be 200 or less.

＜Additives＞ The adhesive composition may also contain other additives. Examples of additives are: silane coupling agents other than Si agent (X), polysiloxane compounds such as silicone oil (excluding silane coupling agents), polyether compounds (polyalkylene glycols such as polypropylene glycol, etc.), Colorants such as pigments and dyes, surfactants, plasticizers, tackifiers, surface lubricants, leveling agents, softeners, antioxidants, antiaging agents, light stabilizers, ultraviolet absorbers, polymerization inhibitors, anti Powders, particles, and foils of electrostatic agents (alkali metal salts of ionic compounds, ionic liquids, ionic solids, etc.), inorganic fillers, organic fillers, and metal powders. When a silane coupling agent other than the Si agent (X) is included, the content of the silane coupling agent may be 0.5% by weight or less, 0.1% by weight or less, 0.05% by weight or less, or less than 0.01% by weight. The adhesive composition may not contain silane coupling agents other than the Si agent (X). When a polysiloxane compound is included, the content of the polysiloxane compound may be 0.5% by weight or less, 0.1% by weight or less, 0.05% by weight or less, and may be less than 0.01% by weight. The adhesive composition may also not contain polysiloxane.

[adhesive layer] The thickness of the adhesive layer 2 is, for example, 1-200 µm, may be 5-150 µm, and may be 10-100 µm. The adhesive layer 2 may be a single layer or may be a laminate including two or more layers. All of the two or more layers may contain the above-mentioned adhesive composition.

The 800% modulus of the adhesive layer 2 at 80°C is, for example, 0.18-0.5 N/mm ² , may be 0.2-0.4 N/mm ² , and may even be 0.2-0.3 N/mm ² . The 800% modulus refers to the characteristic expressed by the value obtained by giving an elongation of 800% to the adhesive layer 2 by a tensile force in one direction, and dividing the stress generated in the adhesive layer 2 at this time (tensile stress) divided by the initial cross-sectional area of the adhesive layer 2. The 800% modulus of the adhesive layer 2 can be evaluated as follows.

Cut the adhesive layer 2 of the evaluation object into a long sheet of 30mm×100mm. Next, the cut-out adhesive layer 2 was wound up along the long side so as not to mix air bubbles, to obtain a cylindrical test piece having a height of 30 mm corresponding to the length of the short side. Next, after the obtained test piece is installed in a tensile testing machine such as TENSILON, a uniaxial tensile test is performed on its height direction to obtain an elongation-stress curve of the adhesive layer 2 . In addition, the preparation of the test piece and the uniaxial tensile test were implemented at 23 degreeC, and the distance between the initial fixtures in the uniaxial tensile test was set to 10 mm, and the tensile speed was set to 300 mm/min. From the obtained elongation-stress curve, calculate the stress when the elongation is 800% (the distance between the fixtures at this time is 90mm), divide it by the initial cross-sectional area of the test piece, and use it as the 800% modulus of the adhesive layer 2 .

The adhesion of the adhesive layer 2 to polyethylene terephthalate (PET) film at 80°C is, for example, 1.8N/25mm or higher, 2.0N/25mm or higher, 2.5N/25mm or higher, or 2.7N/25mm above, above 3.0N/25mm, above 3.2N/25mm, and above 3.5N/25mm. The upper limit of the adhesive force is, for example, 10.0 N/25 mm or less. However, the above-mentioned adhesive force was evaluated in the state where the adhesive layer 2 was disposed on the modified surface of the PET film. In other words, the above-mentioned adhesive force refers to the adhesive force to the modified surface of the PET film.

The total light transmittance (according to JIS K7136) of the adhesive layer 2 in the visible light wavelength region is preferably 85% or more, more preferably 90% or more.

The above-mentioned adhesive composition is an adhesive composition used for disposing on the modified surface 12 of the optical substrate 1 in the optical layered body 100 . From this point of view, the present invention provides an adhesive composition, which is configured on the surface 11 of the optical substrate 1 for users; the adhesive composition includes a silane coupling agent; the aforementioned silane coupling agent contains an isocyanuric acid ring , and does not contain isocyanate groups; the aforementioned surface that can be configured with the aforementioned adhesive composition is a modified surface modified by irradiation energy.

[Formation of Adhesive Layer] The adhesive layer 2 can be formed by the following method, for example. A solvent-based adhesive composition is applied to a base film (peeling film) or the like, and the polymerization solvent or the like is removed by drying. The adhesive layer 2 formed on the base film can be transferred to the surface 11 of the optical substrate 1 . An active energy ray-curable adhesive composition is applied to a base film or the like, and irradiated with active energy ray to harden it. In addition to irradiating active energy rays, drying by heating can also be performed. Also, when coating the adhesive composition, one or more solvents other than the polymerization solvent may be newly added to the composition.

The coated surface of the adhesive composition in the base film may also be peeled off. An example of a release treatment is a silicone treatment using a silicone compound.

The drying temperature is, for example, 40-200°C, may be 50-180°C, and may be 70-170°C. However, it can be adjusted by the composition of the adhesive composition, etc.

The drying time is, for example, 5 seconds to 20 minutes, may be 5 seconds to 10 minutes, and may be 10 seconds to 5 minutes. However, it can be adjusted by the composition of the adhesive composition, etc.

The adhesive composition can be coated by, for example, roll coating, touch roll coating, gravure coating, reverse coating, roll brushing, spray coating, dip roll coating, rod coating, knife coat, air Coating by means of knife coating, curtain coating, lip coating, extrusion coating using a die coater, etc.

[Optical substrate] The optical substrate 1 has a modified surface 12 . The modified surface 12 is a surface modified by irradiation of energy. During surface modification, functional groups are generated on the substrate surface. The surface modification by irradiation energy is at least one selected from corona treatment, plasma treatment, and ultraviolet treatment (excimer laser irradiation, etc.).

Irradiation of energy can be carried out, for example, under a gas environment containing an inert gas such as nitrogen or under air. The energy of irradiation is, for example, 0.05-20 J/cm ² , or 0.1-5 J/cm ² . Irradiation of energy for each treatment can be performed by a known method.

The optical substrate 1 can be made of resin, in other words, it can also be a resin substrate. In addition, at this time, the Si agent (X) may also be localized in the region 21 near the interface 3 with the optical substrate 1 in the adhesive layer 2 . However, the optical substrate 1 is not limited to the resin substrate. Examples of the resin constituting the optical substrate 1 are polyester such as PET, acrylic resin, polyolefin, polycycloolefin, polyimide, polyurethane, and modified cellulose such as cellulose triacetate (TAC). The acrylic resin may also have a ring structure such as an amide ring, an imide ring, an acid anhydride ring, or a lactone ring. However, the resin is not limited to the above examples.

Examples of the optical substrate 1 are polarizing film, polarizer protective film, retardation film, viewing angle compensation film and other optical compensation films, antireflection film, antistatic film, conductive film, buffer film, decorative film, cover window, liquid crystal layer and image forming layers such as organic EL light-emitting layers, and their laminates. However, the optical substrate 1 is not limited to the above examples, and may be any optical substrate used in image display devices, for example.

The polarizing film contains polarizers. A polarizer protective film may also be bonded to at least one side of the polarizer through an adhesive layer. The polarizer is typically a polyvinyl alcohol (PVA) film in which iodine is oriented by various methods such as stretching in the air (dry stretching) or boric acid underwater stretching, and coating.

The retardation film is a film having birefringence in the in-plane direction and/or in the thickness direction. The retardation film is, for example, a stretched resin film, or a film in which liquid crystal materials have been oriented and fixed.

Retardation films are, for example: λ/4 plates, λ/2 plates, retardation films for anti-reflection (for example, refer to paragraphs 0221, 0222, and 0228 of Japanese Patent Application Laid-Open No. 2012-133303), retardation films for viewing angle compensation ( For example, refer to paragraphs 0225 and 0226 of Japanese Patent Application Laid-Open No. 2012-133303), and oblique orientation retardation film for viewing angle compensation (for example, refer to paragraph 0227 of Japanese Patent Application Laid-Open No. 2012-13303). However, the retardation film is not limited to the above examples as long as it has birefringence in the in-plane direction and/or in the thickness direction. There are also no restrictions on the retardation value, arrangement angle, 3-dimensional birefringence, single-layer or multi-layer of the retardation film. The retardation film may be a known film.

The thickness of the retardation film is, for example, less than 50 µm, or less than 20 µm, less than 10 µm, or even 1-9 µm.

The thickness of the optical substrate 1 is, for example, more than 1 µm, may be more than 5 µm, and may be more than 25 µm. The upper limit of the thickness of the optical substrate 1 is, for example, 200 µm or less.

The total light transmittance (according to JIS K7136) of the optical substrate 1 in the visible light wavelength region is preferably 85% or more, more preferably 90% or more.

The total light transmittance (according to JIS K7136) of the optical layered body 100 in the visible light wavelength region is preferably 85% or more, more preferably 90% or more.

The optical laminate 100 in FIG. 1 has an optical substrate 1 and an adhesive layer 2 . The optical layered body of the present invention may also include two or more optical substrates 1 and/or two or more adhesive layers 2 . In other words, the optical laminate of the present invention includes at least one optical substrate 1 and at least one adhesive layer 2 .

The optical laminate 110 in FIG. 2 includes a retardation film 4 , polarizer protective films 5A, 5B, a polarizer 6 , and adhesive layers 7A, 7B, and 7C. In the optical laminate 110, the retardation film 4, the adhesive layer 7A, the polarizer protective film 5A, the adhesive layer 7B, the polarizer 6, the adhesive layer 7C, and the polarizer protective film 5B are sequentially laminated. At least one adhesive layer selected from the three adhesive layers 7A, 7B, and 7C is the above-mentioned adhesive layer 2 . All the adhesive layers 7A, 7B, and 7C may also be the adhesive layer 2 . Moreover, at least one optical substrate in contact with the adhesive layer 2 is the above-mentioned optical substrate 1 . The two optical substrates in contact with the adhesive layer 2 can also be the above-mentioned optical substrate 1 .

When the optical laminate 110 has two or more adhesive layers 2, the composition of the adhesive composition contained in each adhesive layer 2 may be the same or different.

The optical layered body of the present invention may also be an optical substrate with an adhesive layer attached to other members.

An example of an optical substrate with an adhesive layer attached is shown in FIG. 3 . The optical substrate 120 with an adhesive layer in FIG. 3 has an optical substrate 1, an adhesive layer 2, and a release liner 8. The release liner 8 is arranged on the opposite side of the bonding surface of the adhesive layer 2 to the optical substrate 1. side face. The release liner 8 has the function of protecting the adhesive layer 2 when the optical substrate 120 with the adhesive layer is distributed and stored, and is peeled off when the optical substrate 120 with the adhesive is used.

The release liner 8 is typically a resin film. Examples of the resin constituting the release liner 8 are polyester such as PET, polyolefin such as polyethylene and polypropylene, polycarbonate, acrylic resin, polystyrene, polyamide and polyimide. The surface of the release liner 8 that is in contact with the adhesive layer 2 may also have been subjected to a release process. The release treatment is, for example, silicone treatment by silicone. However, the release liner 8 is not limited to the above examples.

The thickness of the release liner 8 is, for example, 20 µm to 100 µm.

The optical substrate 120 with an adhesive may also have two or more optical substrates 1 and/or two or more adhesive layers 2 . In addition, in the adhesive-attached optical substrate 120 having two or more adhesive layers, at least one adhesive layer may be the above-mentioned adhesive layer 2 .

The optical layered body of the present invention may include any layer other than the above.

The optical layered body of the present invention can be distributed and stored, for example, in the form of a single sheet or in the form of a roll formed by winding a tape-shaped layered body.

The optical layered body of the present invention can also be used for image display devices.

[image display device] An example of an image display device is shown in FIG. 4 . The image display device 200 in FIG. 4 has a substrate 51, an adhesive layer 10A, an image forming layer (organic EL layer) 52, an adhesive layer 10B, an optical substrate 1, an adhesive layer 2, and a cover film 53 laminated in this order. structure. The image display device 200 includes the optical layered body 100 . The substrate 51, the image forming layer 52, and the cover film 53 may have the same configurations as those of the substrate, image forming layer, and cover film of a known organic EL display.

At least one selected from the adhesive layer 10A, 10B may be the above-mentioned adhesive layer 2 . At this time, at least one member in contact with the adhesive layer 10A, 10B which is the adhesive layer 2 is the optical base material 1 .

The image display device 200 in FIG. 4 is an organic EL display. However, the image display device 200 of the present invention is not limited to the above example.

The image display device 200 may have any configuration as long as it includes the optical layered body of the present invention.

The image display device 200 can also be a flexible image display device.

Example Hereinafter, the present invention will be described in more detail using examples. The present invention is not limited by the Examples shown below.

The correspondence between the abbreviations or names shown in the following description and the compounds is as follows. BA: butyl acrylate HBA: Hydroxybutyl Acrylate 2EHA: 2-Ethylhexyl Acrylate NVP: N-vinylpyrrolidone D110N: Trimethylolpropane/diisocyanate adduct (TAKENATE D110N manufactured by Mitsui Chemicals, isocyanate-based crosslinking agent) BPO: benzoyl peroxide (peroxide-based crosslinking agent) KBM9659: Ginseng-(trimethoxysilylpropyl)isocyanurate (manufactured by Shin-Etsu Chemical Co., Ltd., Si agent (X)) KBM403: 3-Glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., a silane coupling agent with an epoxy group at the end) KBM573: N-phenyl-3-aminopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., a silane coupling agent with amino groups)

[Production of (meth)acrylic polymer] (Synthesis Example 1) In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen inlet pipe and a cooler, 99 parts by weight of BA and 1 part by weight of HBA were fed into, and diluted with ethyl acetate and toluene into a mixture of BA and HBA. 50% by weight. The ratio of toluene in the solvent used for dilution was set at 5% by weight. Next, 0.1 part by weight of AIBN was added as a polymerization initiator to 100 parts by weight of the mixture of BA and HBA, and nitrogen was introduced into the flask while stirring slowly to replace nitrogen in the flask. hour polymerization. Next, ethyl acetate was added to the obtained reaction liquid, and the solution of (meth)acrylic-type polymer A1 was obtained by adjusting to solid content concentration 20 weight%. Mw of (meth)acrylic polymer A1 was 1.8 million. In addition, Mw of the (meth)acrylic-type polymer produced in each synthesis example was measured by GPC under the following measurement conditions. ・Analyzer: Acquity APC manufactured by Waters ・Column: Made by Tosoh, G7000HXL+GMHXL+GMHXL ・Column temperature: 40°C ・Eluent: Tetrahydrofuran (acid added) ・Flow rate: 0.8mL/min ・Injection volume: 100µL ・Detector: Differential refractometer (RI) ・Standard sample: Polystyrene (PS) manufactured by Agilent

(Synthesis Example 2) 96 parts by weight of 2EHA, 1 part by weight of HBA, and 3 parts by weight of NVP were fed into the flask, and the ratio of toluene in the solvent used for dilution was set to 30% by weight, except in the same manner as in Synthesis Example 1 Thus, a solution of (meth)acrylic polymer A2 was obtained. The Mw of the (meth)acrylic polymer A2 was 1.2 million.

(Synthesis Example 3) A solution of (meth)acrylic polymer A3 was obtained in the same manner as in Synthesis Example 2 except that the ratio of toluene in the solvent used for dilution was 5% by weight. The Mw of the (meth)acrylic polymer A3 was 2 million.

(Synthesis Example 4) The proportion of toluene in the solvent used for dilution is set to 0% by weight, the amount of the polymerization initiator is set to 0.05 parts by weight of AIBN, and the time of the polymerization reaction is set to 2 hours. 2. Obtain the solution of (meth)acrylic polymer A4 in the same manner. Mw of (meth)acrylic polymer A4 was 2.8 million.

The (meth)acrylic polymers produced in each synthesis example are summarized in Table 1 below.

[Table 1]

[Production of adhesive composition] The (meth)acrylic polymer solution, the crosslinking agent, and the silane coupling agent were mixed so as to have the composition shown in Table 2 below, to obtain solvent-based adhesive compositions P1 to P11. In addition, the content rate of a polymer, a crosslinking agent, and a silane coupling agent is the value converted into solid content.

[Table 2]

[Production of Optical Laminate] (Example 1) The prepared adhesive composition P1 was coated on the release-treated surface of a release film (manufactured by Mitsubishi Plastics, MRF#38) with a fountain coater, and set Dry it in an air-circulating constant temperature oven at 155°C for 2 minutes to form an adhesive composition layer (thickness 20µm). In addition, a PET film (thickness: 75 µm) of a modified surface subjected to corona treatment in air (irradiation energy amount: 0.3 J/cm ² ) was prepared as an optical base material. The adhesive composition layer formed above was bonded to the modified surface of the prepared PET film to produce an optical laminate with an adhesive layer and an optical substrate. In addition, lamination was carried out so that the portion not in contact with the adhesive layer was formed with a width of 50 mm or more from one side of the PET film.

(Example 2~9) The optical laminates of Examples 2 to 9 were obtained in the same manner as in Example 1, except that the adhesive compositions P2 to P9 were used instead of the adhesive composition P1.

(comparative example 1) The adhesive composition P3 was used to replace the adhesive composition P1, and a PET film (same thickness) without a modified surface was used as the optical substrate, and the comparative example 1 was obtained in the same manner as in Example 1 except that Optical laminates.

(comparative example 2) The adhesive composition P10 was used to replace the adhesive composition P1, and a PET film (same thickness) without a modified surface was used as the optical substrate, and the comparative example 2 was obtained in the same manner as in the example 1. Optical laminates.

(comparative example 3) An optical layered body of Comparative Example 3 was obtained in the same manner as in Example 1 except that the adhesive composition P10 was used instead of the adhesive composition P1.

(comparative example 4) An optical layered body of Comparative Example 4 was obtained in the same manner as in Example 1 except that the adhesive composition P11 was used instead of the adhesive composition P1.

[Assessment] [Whether the Si agent (X) is biased or not] For the optical laminates of Example 3 and Comparative Example 1, it is evaluated whether the Si agent (X) can be observed in the adhesive layer by TOF-SIMS using etching ions The partial storage. In this evaluation method, elemental analysis can be performed in the thickness direction of the adhesive layer. The evaluation conditions of TOF-SIMS are as follows.・Device: Made by ULVAC-PHI, TRIFT-V ・Evaluation object: m/z=45 corresponding to SiOH ⁺ ion ・Etching ion: Ar gas cluster ion ・Etching ion acceleration voltage: 10kV ・Irradiated primary ion: Bi ₃ ^{2 +}・Primary ion acceleration voltage: 30kV ・Etching from the exposed surface of the adhesive layer to the direction of the optical substrate

The evaluation results of the respective optical layered bodies of Example 3 and Comparative Example 1 are shown in FIGS. 5A and 5B , respectively. In the plots of FIGS. 5A and 5B , the horizontal axis is the etching time (unit: second), and the vertical axis is the normalized intensity of SiOH ⁺ ions after normalization based on the intensity of C ₂ H ₃ ⁺ ions. As shown in FIG. 5A , in the optical layered body of Example 3, it was confirmed that the Si agent (X) was segregated (hatched portion) in the region 21 near the interface with the PET film in the adhesive layer. In the plot of FIG. 5A , the area sum of the SiOH ^{+ peaks in the region 21 (accounting for 20% of the thickness of the adhesive layer) is more than 90% of the area sum of the SiOH + peaks} that can be measured in the adhesive layer. On the other hand, as shown in FIG. 5B , in the optical layered body of Comparative Example 1, no partiality of the Si agent (X) was observed. Due to the combination of the Si agent (X) and the modified surface of the optical substrate, it was confirmed that the partiality of the Si agent (X) occurred. In addition, in the plots of the respective figures, a larger intensity of SiOH ⁺ ions was also observed in the region inside the PET film. We believe that this is because the intensity of C ₂ H ₃ ⁺ ions, which is a standardization standard, becomes very small in PET films compared to an adhesive layer containing a (meth)acrylic polymer.

[800% modulus] The 800% modulus of the adhesive layer was evaluated as follows. Cut the adhesive layer formed on the release film into a rectangular shape with a width of 30mm and a length of 100mm, and roll it into a cylindrical shape in such a way that air bubbles do not enter as a measurement sample. Using a tensile testing machine, obtain the stress at the elongation rate of 800% from the elongation-stress curve of the test sample measured under the conditions of the initial fixture distance of 10 mm and the tensile speed of 300 mm/min, and obtain it from Calculate the 800% modulus (N/mm ² ) of the stress. In addition, the elongation rate of 800% means the state where the distance between jigs becomes 90 mm. As a tensile tester, Autograph AG-IS manufactured by Shimadzu Corporation was used. The evaluation was carried out at normal temperature (23°C).

[High temperature adhesion] The high temperature (80° C.) adhesion of the adhesive layer to the optical substrate was evaluated as follows. Another PET film (thickness 75 µm) subjected to the same corona treatment as above was bonded to the optical layered body produced in each Example and Comparative Example. Next, the laminated body obtained by bonding was cut into the long sheet shape of width 25mm and length 150mm, and the sample for a measurement was obtained. The bonding system is carried out by the following method: when the adhesive layer of the optical laminate is brought into contact with the modified surface of another PET film, and when it is cut into a long sheet, at one end of the laminate in the longitudinal direction, the other The PET film has a first free end (50 mm in length) that is not in contact with the adhesive layer. Also, at the time of bonding, a pressure bonding roller with a mass of 2 kg specified in Japanese Industrial Standards (former Japanese Industrial Standards; JIS) Z0237:2009 was reciprocated once at a temperature of 25°C. Cutting was carried out so that the part of the optical base material provided when producing the optical laminate that was not in contact with the adhesive layer was located at the other end in the longitudinal direction as the second free end (50 mm in length). Thereafter, the measurement sample after standing still for 30 minutes was installed in a tensile testing machine with a constant temperature bath. The installation is implemented by making one of the jigs of the testing machine hold the first free end, and make the other jig hold the second free end. Next, the ambient temperature of the testing machine and the test sample was controlled to the evaluation temperature (80° C.). After the ambient temperature reaches the evaluation temperature, let it stand for 5 minutes, and then pull the two free ends in opposite directions at a test speed of 300 mm/min to perform a peel test. After the start of the test, ignore the initial measured value (stress value) measured until the stretching distance (expansion distance between fixtures) from the initial state reaches 10mm, and then use the stress measured until the stretching distance from the initial state reaches 80mm The average value of the value is taken as the high temperature adhesion.

The evaluation results of the respective optical layered bodies of Examples and Comparative Examples are shown in Table 3 below.

[table 3]

As shown in Table 3, the optical laminates of the examples can maintain the cohesive force of the adhesive layer while improving the high-temperature adhesive force. In addition, when the adhesive composition includes a silane coupling agent with an epoxy group at the end, the improvement of the high-temperature adhesive force brought about by the surface modification of the PET film is small (Comparative Examples 2 and 3).

Industrial availability The optical layered body of the present invention can be used, for example, in an image display device.

1: Optical substrate 10A, 10B, 2, 7A, 7B, 7C: adhesive layer 11: surface 12: modified surface 21: area 3: interface 4: Retardation film 51: Substrate 52: Image forming layer (organic EL layer) 53: Cover film 5A, 5B: Polarizer protective film 6: Polarizer 8: Peel off the liner 100,110,120: optical laminates 200: image display device

Fig. 1 is a cross-sectional view schematically showing an example of the optical layered body of the present invention. Fig. 2 is a cross-sectional view schematically showing another example of the optical layered body of the present invention. Fig. 3 is a cross-sectional view schematically showing still another example of the optical layered body of the present invention. FIG. 4 is a cross-sectional view schematically showing an example of the image display device of the present invention. FIG. 5A is a graph showing the distribution of silane coupling agent in the adhesive layer of the optical laminate produced in Example 3. FIG. 5B is a graph showing the distribution of the silane coupling agent in the adhesive layer of the optical laminate produced in Comparative Example 1. FIG.

1: Optical substrate

11: surface

12: modified surface

2: Adhesive layer

21: area

3: interface

100: Optical laminate

Claims (9)

An optical laminate comprising an optical substrate and an adhesive layer disposed on the surface of the optical substrate; The aforementioned adhesive layer comprises an adhesive composition containing a silane coupling agent; The aforementioned silane coupling agent contains an isocyanuric acid ring and does not contain an isocyanate group; The above-mentioned surface on which the above-mentioned adhesive layer is disposed is a modified surface whose surface is modified by irradiating energy. The optical laminate according to claim 1, wherein the silane coupling agent is localized in a region near the interface between the adhesive layer and the optical substrate. The optical laminate according to claim 1 or 2, wherein the content of the silane coupling agent in the adhesive composition is 0.05% by weight or more and 1.0% by weight or less. The optical laminate according to any one of claims 1 to 3, wherein the optical substrate is made of resin. The optical laminate according to any one of claims 1 to 4, wherein the adhesive composition comprises a (meth)acrylic polymer. The optical laminate according to claim 5, wherein the (meth)acrylic polymer has a weight average molecular weight of 1.8 million or more. The optical laminate according to any one of claims 1 to 6, wherein the surface modification by irradiation energy is at least one selected from corona treatment, plasma treatment and ultraviolet treatment. An image display device comprising: the optical laminate according to any one of Claims 1 to 7; and an image forming layer. An adhesive composition, configured on the surface of an optical substrate; The adhesive composition comprises a silane coupling agent; The aforementioned silane coupling agent contains an isocyanuric acid ring and does not contain an isocyanate group; The aforementioned surface on which the aforementioned adhesive composition can be placed is a modified surface modified by irradiating energy.

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