Adhesive composition and bonded object

Abstract

A main purpose of the present disclosure is to provide an adhesive composition which contains a (meth)acrylate having a fluorine-containing organic group and which nevertheless can give cured objects having sufficient adhesion strength and a high infrared-light transmittance.　The adhesive composition comprises a (meth) acrylate compound, an epoxy compound, a crosslinking agent, and a photoacid generator. The (meth) acrylate compound includes a (meth) acrylate having a fluorine-containing organic group. The crosslinking agent includes a (meth)acrylic resin comprising a first structural unit, which is derived from a (meth)acrylate having a fluorine-containing organic group, and a second structural unit, which is derived from a (meth)acrylate having a cyclic ether group.

Description

Adhesive composition and adhesive body

[0001] The present disclosure relates to an adhesive composition and an adhesive body.

[0002] As an adhesive composition, a photocurable composition containing a (meth)acrylate compound, an epoxy compound, and a photoacid generator is known (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2018-141137

[0004] Polymers of compounds having a fluorine-containing organic group have attracted attention as materials exhibiting a low refractive index. The present inventors focused on adhesive compositions containing a (meth)acrylate compound, an epoxy compound, and a photoacid generator, and investigated the curing reaction using a (meth)acrylate having a fluorine-containing organic group as the (meth)acrylate compound. They found that the adhesive strength of the cured product of the adhesive composition obtained tends to decrease, and furthermore, the infrared transmittance of the cured product of the adhesive composition also tends to decrease.

[0005] A primary object of the present disclosure is to provide an adhesive composition that, when a (meth)acrylate having a fluorine-containing organic group is used, can give a cured product that has sufficient adhesive strength and high infrared transmittance.

[0006] The present inventors conducted extensive research to solve the above problems and discovered that by applying a specific crosslinking agent to an adhesive composition, sufficient adhesive strength can be achieved and the infrared transmittance of the cured product can also be improved, leading to the completion of the presently disclosed invention.

[0007] The present disclosure includes the following items [1] to [6]. [1] An adhesive composition comprising a (meth)acrylate compound, an epoxy compound, a crosslinking agent, and a photoacid generator, wherein the (meth)acrylate compound comprises a (meth)acrylate having a fluorine-containing organic group, and the crosslinking agent comprises a (meth)acrylic resin having a first structural unit derived from the (meth)acrylate having a fluorine-containing organic group and a second structural unit derived from a (meth)acrylate having a cyclic ether group. [2] The adhesive composition according to item [1], wherein the content of the first structural unit is 10 to 90 mol % based on all structural units of the (meth)acrylic resin, and the content of the second structural unit is 10 to 90 mol % based on all structural units of the (meth)acrylic resin. [3] The adhesive composition according to item [1] or [2], wherein the epoxy compound comprises an aliphatic epoxy compound. [4] The adhesive composition according to item [3], wherein the epoxy compound further comprises an alicyclic epoxy compound. [5] The adhesive composition according to any one of [1] to [4], further comprising an oxetane compound. [6] An adhesive body comprising a first adherend, a second adherend, and an adhesive joint that bonds the first adherend and the second adherend to each other, wherein the adhesive joint contains a cured product of the adhesive composition according to any one of [1] to [5].

[0008] According to the present disclosure, there is provided an adhesive composition that can give a cured product having sufficient adhesive strength and high infrared transmittance when a (meth)acrylate having a fluorine-containing organic group is used, and an adherend using such an adhesive composition.

[0009] Hereinafter, embodiments of the present disclosure will be described, but the present disclosure is not limited to the following embodiments.

[0010] In this specification, a numerical range indicated using "to" indicates a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In numerical ranges described in stages in this specification, the upper or lower limit of a certain numerical range may be replaced with the upper or lower limit of another numerical range. Furthermore, in a numerical range described in this specification, the upper or lower limit of that numerical range may be replaced with a value shown in the examples. Furthermore, individually described upper and lower limits can be arbitrarily combined. In a numerical range described as "A to B," the numerical values ​​A and B at both ends are included as the lower and upper limits, respectively, in the numerical range. In this specification, for example, the term "10 or more" means "10" and "a number greater than 10," and this also applies when the numerical values ​​are different. Furthermore, for example, the term "10 or less" means "10" and "a number less than 10," and this also applies when the numerical values ​​are different.

[0011] In this specification, a (meth)acrylate compound refers to a compound having one or more (meth)acryloyl groups, and a (meth)acrylic resin refers to a (co)polymer having at least a structural unit derived from a (meth)acrylate compound. The (meth)acrylate compound may be a compound that does not have an epoxy group or an oxetanyl group. A (meth)acryloyl group refers to an acryloyl group or a corresponding methacryloyl group. The same applies to other similar expressions such as (meth)acrylate. Furthermore, "A or B" may include either A or B, or may include both.

[0012] In this specification, the term "cyclic ether group" refers to a group obtained by removing one hydrogen atom directly bonded to a carbon atom from a compound having a cyclic ether such as oxirane or oxetane. The cyclic ether group may be a group obtained by removing one hydrogen atom directly bonded to a carbon atom from a compound having a three- or four-membered cyclic ether. Examples of such cyclic ether groups include epoxy groups (oxiranyl groups) and oxetanyl groups. The epoxy group includes alicyclic epoxy groups (epoxy groups formed together with two carbon atoms constituting an alicyclic ring) such as epoxycyclohexyl groups.

[0013] Unless otherwise specified, the materials exemplified below may be used alone or in combination of two or more. When a composition contains multiple substances corresponding to each component, the amount used or content of each component means the total amount of the multiple substances present in the composition, unless otherwise specified.

[0014] [Adhesive Composition] The adhesive composition of one embodiment contains a (meth)acrylate compound (hereinafter sometimes referred to as "component (A)"), an epoxy compound (hereinafter sometimes referred to as "component (B)"), a crosslinking agent (hereinafter sometimes referred to as "component (C)"), and a photoacid generator (hereinafter sometimes referred to as "component (D)"). The adhesive composition may further contain, for example, a photoradical generator (hereinafter sometimes referred to as "component (E)") and an oxetane compound (hereinafter sometimes referred to as "component (F)").

[0015] Component (A): (meth)acrylate compound The component (A) contains a (meth)acrylate having a fluorine-containing organic group (hereinafter, sometimes referred to as "component (A1)"). The component (A) may further contain a (meth)acrylate having a hydroxy group (hereinafter, sometimes referred to as "component (A2)"). The component (A) may further contain a (meth)acrylate having an alkoxy group (hereinafter, sometimes referred to as "component (A3)").

[0016] By including the component (A1) in the component (A), it is possible to achieve a low refractive index in the cured product of the adhesive composition. The component (A1) may be, for example, a (meth)acrylate having a fluoroalkyl group. Examples of (meth)acrylates having a fluoroalkyl group include trifluoromethyl (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate, 1,1,1,3,3,3-hexafluoro-2-propyl (meth)acrylate, perfluoroethylmethyl (meth)acrylate, perfluoropropylmethyl (meth)acrylate, perfluorobutylmethyl (meth)acrylate, perfluoropentylmethyl (meth)acrylate, perfluorohexylmethyl (meth)acrylate, perfluoroheptylmethyl (meth)acrylate, perfluorooctylmethyl (meth)acrylate, perfluorononylmethyl (meth)acrylate, perfluorodecylmethyl (meth)acrylate, perfluoroundecylmethyl (meth)acrylate, and perfluorododecylmethyl (meth)acrylate. acrylate, perfluorotridecylmethyl (meth)acrylate, perfluorotetradecylmethyl (meth)acrylate, 2-(trifluoromethyl)ethyl (meth)acrylate, 2-(perfluoroethyl)ethyl (meth)acrylate, 2-(perfluoropropyl)ethyl (meth)acrylate, 2-(perfluorobutyl)ethyl (meth)acrylate, 2-(perfluoropentyl)ethyl (meth)acrylate, 2-(perfluorohexyl)ethyl (meth)acrylate, 2-(perfluoroheptyl)ethyl (meth)acrylate, 2-(perfluorooctyl)ethyl (meth)acrylate, 2-(perfluorononyl)ethyl (meth)acrylate, 2-(perfluorotridecyl)ethyl (meth)acrylate, 2-(perfluorotetradecyl)ethyl (meth)acrylate, and the like.

[0017] In the (meth)acrylate having a fluoroalkyl group as the component (A1), the number of carbon atoms in the fluoroalkyl group may be, for example, 1 to 20, 2 or more, 3 or more, 4 or more, or 6 or more, or may be 18 or less, 16 or less, 14 or less, or 12 or less, from the viewpoint of reducing the refractive index of the cured product.

[0018] In a (meth)acrylate having a fluoroalkyl group as component (A1), the proportion of fluorine atoms in the fluoroalkyl group is calculated based on the total amount of hydrogen atoms and fluorine atoms directly bonded to carbon atoms constituting the fluoroalkyl group. For example, the trifluoromethyl group of trifluoromethyl (meth)acrylate has three fluorine atoms and no hydrogen atoms, so the proportion of fluorine atoms is 100%. For example, the 2,2,2-trifluoroethyl group of 2,2,2-trifluoroethyl (meth)acrylate has three fluorine atoms and two hydrogen atoms, so the proportion of fluorine atoms is 60%. From the viewpoint of lowering the refractive index of the cured product, the proportion of fluorine atoms may be, for example, 100% or less, 90% or less, or 80% or less, or 30% or more, 40% or more, or 50% or more.

[0019] From the viewpoint of achieving a low refractive index of the cured product, the content of the component (A1) may be 15% by mass or more, 25% by mass or more, 30% by mass or more, 35% by mass or more, 40% by mass or more, or 45% by mass or more, and may be 70% by mass or less, 65% by mass or less, or 60% by mass or less, based on the total amount of the component (A).

[0020] By including component (A2) in component (A), the curability and adhesion of the adhesive composition can be further improved. Component (A2) may be, for example, a (meth)acrylate having a hydroxyalkyl group. Examples of (meth)acrylates having a hydroxyalkyl group include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate.

[0021] From the viewpoint of the curability and adhesion of the adhesive composition, the content of component (A2) may be 0.1 mass % or more, 1 mass % or more, or 2 mass % or more, and may be 15 mass % or less, 12 mass % or less, 10 mass % or less, or 8 mass % or less, based on the total amount of component (A).

[0022] By including the component (A3) in the component (A), the solubility of the component (C), which will be described later, can be further improved, and further the transmittance of the cured product of the adhesive composition can be further improved. The component (A3) may be, for example, a (meth)acrylate having an alkoxyalkyl group. Examples of the component (A3) include 2-methoxyethyl acrylate and 2-ethoxyethyl (meth)acrylate.

[0023] From the viewpoint of the solubility of the component (C), the content of the component (A3) may be 5% by mass or more, 10% by mass or more, 20% by mass or more, 30% by mass or more, or 35% by mass or more, and may be 65% by mass or less, 60% by mass or less, 55% by mass or less, or 50% by mass or less, based on the total amount of the component (A).

[0024] The component (A) may contain another (meth)acrylate (hereinafter, sometimes referred to as "component (A4)") to the extent that the effects of the present disclosure are not impaired. Examples of the component (A4) include monofunctional (meth)acrylates having one (meth)acryloyl group other than the components (A1), (A2), and (A3), and polyfunctional (meth)acrylates having two or more (meth)acryloyl groups other than the components (A1), (A2), and (A3).

[0025] Examples of monofunctional (meth)acrylates include alkyl (meth)acrylates having an alkyl group such as methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-hexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecyl (meth)acrylate, and dodecyl (meth)acrylate; alkenyl (meth)acrylates having an alkenyl group such as 3-butenyl (meth)acrylate; (meth)acrylates having an aromatic group such as benzyl (meth)acrylate and phenoxyethyl (meth)acrylate; cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, and the like. (meth)acrylates having an alicyclic group such as 4-(meth)acryloylmorpholine; (meth)acrylates having a heterocyclic group such as 4-(meth)acryloylmorpholine; alkoxypolyalkylene glycol (meth)acrylates such as methoxyethylene glycol (meth)acrylate, methoxytetraethylene glycol (meth)acrylate, methoxyhexaethylene glycol (meth)acrylate, and methoxyoctaethylene glycol (meth)acrylate; polyalkylene glycol mono(meth)acrylates such as tetraethylene glycol mono(meth)acrylate, hexaethylene glycol mono(meth)acrylate, and octapropylene glycol mono(meth)acrylate; and (meth)acrylates having a siloxane skeleton.

[0026] Examples of polyfunctional (meth)acrylates include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, tetrapropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, ethoxylated polypropylene glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, aliphatic (meth)acrylates such as ethoxylated bisphenol A di(meth)acrylate, propoxylated bisphenol A di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, glycerin di(meth)acrylate, tricyclodecane dimethanol (meth)acrylate, ethoxylated 2-methyl-1,3-propanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, and ethoxylated trimethylolpropane tri(meth)acrylate; Examples of the aromatic (meth)acrylate include propoxylated bisphenol A di(meth)acrylate, ethoxylated bisphenol F di(meth)acrylate, propoxylated bisphenol F di(meth)acrylate, ethoxylated propoxylated bisphenol F di(meth)acrylate, ethoxylated fluorene di(meth)acrylate, propoxylated fluorene di(meth)acrylate, and ethoxylated propoxylated fluorene di(meth)acrylate.

[0027] The content of the component (A4) may be 0 to 45 mass%, 0 to 40 mass%, 0 to 30 mass%, 0 to 25 mass%, 0 to 10 mass%, or 0 to 5 mass%, based on the total amount of the component (A).

[0028] The content of the component (A) (total amount of the components (A1), (A2), (A3), and (A4)) may be 20% by mass or more or 30% by mass or more, and may be 70% by mass or less, 65% by mass or less, 60% by mass or less, or 55% by mass or less, based on the total amount of the adhesive composition.

[0029] Component (B): Epoxy Compound Component (B) is a compound having one or more epoxy groups. Component (B) may be a compound that does not have a (meth)acryloyl group or an oxetanyl group. Component (B) may be a compound that has two or more epoxy groups. Component (B) may contain an aliphatic epoxy compound (hereinafter sometimes referred to as "component (B1)"). Component (B1) is a compound that has an epoxy group other than an alicyclic epoxy group. Component (B) may contain an alicyclic epoxy compound (hereinafter sometimes referred to as "component (B2)"). Component (B2) is a compound that has an alicyclic epoxy group. Component (B) may contain both component (B1) and component (B2).

[0030] When component (B) contains component (B1), the compatibility and crosslinkability of the adhesive composition tend to be improved. Component (B1) may be, for example, an aliphatic diglycidyl ether having at least one aliphatic group (linking group) selected from the group consisting of an alkylene group, an oxyalkylene group, and a cycloalkylene group. Component (B1) may also be an epoxy compound having no aromatic ring.

[0031] Examples of aliphatic diglycidyl ethers include diglycidyl ethers having an alkylene group, such as ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, and 1,6-hexanediol diglycidyl ether; diglycidyl ethers having an oxyalkylene group, such as diethylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, and polyethylene glycol diglycidyl ether; and diglycidyl ethers having a cycloalkylene group, such as hydrogenated bisphenol A diglycidyl ether, 1,4-cyclohexanedimethanol diglycidyl ether, and diglycidyl-1,2-cyclohexanedicarboxylate.

[0032] Examples of the component (B1) other than the aliphatic diglycidyl ether include EHPE3150 (1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol, manufactured by Daicel Corporation).

[0033] The content of the (B1) component, based on the total amount of the (B) component, may be 5% by mass or more, 10% by mass or more, 20% by mass or more, 30% by mass or more, 40% by mass or more, or 50% by mass or more, and may be 100% by mass or less, 95% by mass or less, 90% by mass or less, or 80% by mass or less.

[0034] Component (B2) is a compound having an epoxy group (e.g., an epoxycyclohexyl group) formed together with two carbon atoms constituting an alicyclic ring. When component (B) contains component (B2), the heat resistance and crosslinkability of the adhesive composition tend to be improved. Examples of commercially available products of component (B2) include CELLOXIDE (registered trademark) 8010, 2021P, and 2081 (product names, all manufactured by Daicel Corporation). Component (B2) may also be an epoxy compound without an aromatic ring.

[0035] The content of the (B2) component, based on the total amount of the (B) component, may be 0% by mass or more, 5% by mass or more, 10% by mass or more, or 20% by mass or more, and may be 95% by mass or less, 90% by mass or less, 80% by mass or less, 70% by mass or less, 60% by mass or less, or 55% by mass or less.

[0036] In addition to the components (B1) and (B2), the component (B) may contain another epoxy compound (hereinafter, sometimes referred to as "component (B3)") to the extent that the effects of the present disclosure are not impaired. Examples of the other epoxy compound include epoxy compounds having an aromatic ring.

[0037] Examples of the component (B3) include phthalic acid diglycidyl ester, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD ​​type epoxy resin, bisphenol S type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, biphenyl type epoxy resin, and biphenyl aralkyl type epoxy resin.

[0038] The content of the component (B3) may be 0 to 40 mass %, 0 to 30 mass %, 0 to 20 mass %, or 0 to 10 mass % based on the total amount of the component (B).

[0039] The content of the (B) component (total amount of the (B1) component, the (B2) component, and the (B3) component) may be 5 mass % or more, 10 mass % or more, 15 mass % or more, or 20 mass % or more, and may be 50 mass % or less, 45 mass % or less, or 40 mass % or less, based on the total amount of the adhesive composition.

[0040] Component (C): Crosslinking Agent The component (C) contains a (meth)acrylic resin having a first structural unit derived from a (meth)acrylate having a fluorine-containing organic group and a second structural unit derived from a (meth)acrylate having a cyclic ether group. The crosslinking agent may consist of the (meth)acrylic resin.

[0041] The (meth)acrylate having a fluorine organic group that provides the first structural unit may be, for example, a (meth)acrylate having a fluoroalkyl group. Examples of the (meth)acrylate having a fluoroalkyl group include those exemplified for the component (A1).

[0042] In the (meth)acrylate having a fluoroalkyl group, the number of carbon atoms in the fluoroalkyl group may be, for example, 1 to 10, 2 or more, or 8 or less, 6 or less, 4 or less, or 3 or less, from the viewpoint of compatibility with the component (A) or a polymer thereof.

[0043] In a (meth)acrylate having a fluoroalkyl group, the proportion of fluorine atoms in the fluoroalkyl group may be, for example, 100% or less, 80% or less, or 70% or less, or may be 30% or more, 40% or more, or 50% or more, from the viewpoint of compatibility with component (A) or a polymer thereof.

[0044] The content of the first structural unit may be 10 to 90 mol%, 20 to 90 mol%, 30 to 90 mol%, or 40 to 90 mol%, based on all structural units of the (meth)acrylic resin, from the viewpoint of compatibility with the component (A) or a polymer thereof.

[0045] The (meth)acrylate having a cyclic ether group that provides the second structural unit may be, for example, at least one selected from the group consisting of (meth)acrylates having an epoxy group and (meth)acrylates having an oxetanyl group. Examples of (meth)acrylates having an epoxy group include (meth)acrylates having an alicyclic epoxy group such as 3,4-epoxycyclohexylmethyl (meth)acrylate, and (meth)acrylates having an epoxy group other than an alicyclic epoxy group such as glycidyl (meth)acrylate. Examples of (meth)acrylates having an oxetanyl group include (3-ethyloxetan-3-yl)methyl (meth)acrylate. The (meth)acrylate having a cyclic ether group may be, for example, a (meth)acrylate having an alicyclic epoxy group.

[0046] In the (meth)acrylic resin, the content of the second structural unit may be 10 to 90 mol %, 10 to 80 mol %, 10 to 70 mol %, or 10 to 60 mol % based on all structural units of the (meth)acrylic resin, from the viewpoint of crosslinkability with the (B) component and the like.

[0047] The (meth)acrylic resin may have structural units other than the first structural unit and the second structural unit, as long as the effects of the present disclosure are not impaired. Examples of compounds that provide such structural units include monofunctional (meth)acrylates having one (meth)acryloyl group, such as alkyl(meth)acrylates having an alkyl group, (meth)acrylates having an aromatic group, (meth)acrylates having an alicyclic group, (meth)acrylates having a nitrogen-oxygen heterocyclic group, alkoxypolyalkylene glycol (meth)acrylates, polyalkylene glycol mono(meth)acrylates, and (meth)acrylates having a siloxane skeleton; polyfunctional (meth)acrylates having two or more (meth)acryloyl groups, such as aliphatic poly(meth)acrylates and aromatic poly(meth)acrylates; and compounds having a radical polymerizable group other than a (meth)acryloyl group, such as styrene, 4-methylstyrene, vinylpyridine, vinylpyrrolidone, vinyl acetate, cyclohexylmaleimide, and phenylmaleimide.

[0048] The content of the other structural units may be 0 to 40 mol %, 0 to 30 mol %, 0 to 20 mol %, or 0 to 10 mol % based on all structural units of the (meth)acrylic resin.

[0049] The weight average molecular weight (Mw) of the (meth)acrylic resin may be, for example, 1,000 to 200,000, 3,000 or more, 5,000 or more, or 10,000 or more, and may be 150,000 or less, 100,000 or less, 60,000 or less, or 50,000 or less. The weight average molecular weight (Mw) is a polystyrene-equivalent value measured by gel permeation chromatography (GPC) using a calibration curve with standard polystyrene. The weight average molecular weight (Mw) can be measured, for example, by the method described in the Examples.

[0050] The (meth)acrylic resin can be obtained, for example, by radical polymerization using a solution polymerization method. More specifically, it can be obtained by polymerizing, in a solvent, monomers including a (meth)acrylate having a cyclic ether group and a (meth)acrylate having a fluorine-containing organic group.

[0051] The solvent can be appropriately selected from organic solvents commonly used in the field of radical polymerization. The solvent may be a solvent having a cyclic ether group (epoxy group or oxetanyl group) but no radical polymerizable group, since the crosslinking agent ((meth)acrylic resin) can be directly used in the polymerization reaction for the curing reaction of a curable resin such as a compound (epoxy resin) having a cyclic ether group without isolating the crosslinking agent ((meth)acrylic resin) (without removing or replacing the solvent). Examples of the solvent include those commonly used in the field of epoxy resin diluents. Examples of the solvent include epoxy resins that are liquid at 25°C. The solvent may be, for example, an aliphatic diglycidyl ether, from the viewpoint of being usable as component (B1). Examples of the aliphatic diglycidyl ether include those exemplified for component (B1).

[0052] In this specification, the radical polymerizable group refers to a group having a carbon-carbon double bond. Examples of the radical polymerizable group include a (meth)acryloyl group, a vinyl group, an allyl group, a styryl group, an alkenyl group, an alkenylene group, and a maleimide group.

[0053] The amount of the solvent used can be appropriately determined depending on the type of monomer, reaction conditions, solids concentration of the (meth)acrylic resin solution, and the like.

[0054] When polymerizing the monomers, a thermal radical generator, an additive, etc. may be added as needed.

[0055] Examples of the thermal radical generator include organic peroxides such as cumene hydroperoxide, diisopropylbenzene hydroperoxide, di-t-butyl peroxide, lauroyl peroxide, benzoyl peroxide, t-butylperoxyisopropyl carbonate, t-amylperoxy-2-ethylhexanoate, and t-butylperoxy-2-ethylhexanoate; and azo compounds such as 2,2'-azobis(isobutyronitrile), 1,1'-azobis(cyclohexanecarbonitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), and dimethyl-2,2'-azobis(2-methylpropionate).

[0056] The amount of the thermal radical generator added may be appropriately set depending on the type of monomer, reaction conditions, etc., and is not particularly limited, but may be 100 to 200,000 ppm by mass, 100 to 100,000 ppm by mass, 1,000 to 100,000 ppm by mass, 1,000 to 50,000 ppm by mass, 3,000 to 30,000 ppm by mass, or 10,000 to 80,000 ppm by mass, based on the total amount of the monomers.

[0057] Examples of the additives include chain transfer agents, antioxidants, light stabilizers, weather stabilizers, ultraviolet absorbers, radical scavengers, etc. The amount of the additives added is not particularly limited, but may be 0.001 to 2% by mass or 0.005 to 1% by mass based on the total amount of the monomers.

[0058] The polymerization temperature may be 40 to 120° C., 50 to 100° C., or 60 to 90° C. The polymerization time may be 0.1 to 24 hours, 0.5 to 20 hours, or 1 to 12 hours.

[0059] The content of component (C) may be 5% by mass or more, 8% by mass or more, 10% by mass or more, 12% by mass or more, or 15% by mass or more, based on the total amount of the adhesive composition, and may be 40% by mass or less, 35% by mass or less, or 30% by mass or less.

[0060] Component (D): Photoacid Generator The component (D) is a component that generates an acid that initiates polymerization upon irradiation with light. The component (D) may be a component that generates an acid that initiates polymerization upon irradiation with light containing a wavelength in the range of 150 to 750 nm or light containing a wavelength in the range of 254 to 405 nm. The component (D) may also be a component that generates radicals that initiate radical polymerization upon irradiation with light. The component (D) may be a component that generates radicals and an acid upon irradiation with light, or a component that generates radicals and an acid upon irradiation with ultraviolet light.

[0061] Examples of the component (D) include onium salts such as sulfonium salts, phosphonium salts, ammonium salts, diazonium salts, iodonium salts, and anilinium salts. Examples of the anion of the onium salt include BF ４ － , B.R. ４ － (R represents a phenyl group substituted with two or more fluorine atoms or two or more trifluoromethyl groups), PF ６ － , SbF ６ － , AsF ６ － , S.O. ４ R － (R represents an alkyl group), etc.

[0062] Examples of commercially available products of component (D) include CPI-100P, CPI-110P, CPI-101A, CPI-200K, and CPI-210S (all manufactured by San-Apro Ltd.), UVI-6990, UVI-6992, and UVI-6976 (all manufactured by Dow Chemical Japan Ltd.), and SP-150, SP-152, SP-170, SP-172, and SP-300 (all manufactured by ADEKA Corporation).

[0063] The content of the (D) component may be, for example, 0.1 parts by mass or more, 0.5 parts by mass or more, or 1 part by mass or more, and may be 15 parts by mass or less, 10 parts by mass or less, or 8 parts by mass or less, relative to 100 parts by mass of the total amount of the (B) component and the (C) component.

[0064] Component (E): Photoradical Generator Component (E) may be a component that generates radicals upon irradiation with light having a wavelength in the range of 150 to 750 nm or light having a wavelength in the range of 254 to 405 nm. Component (E) may be a component that generates radicals upon irradiation with ultraviolet light. Component (E) may be a component that acts mainly on component (A).

[0065] The component (E) generates free radicals when exposed to light. In other words, the component (E) is a compound that generates radicals when exposed to external light energy. The component (E) may be a compound having an oxime ester structure, a bisimidazole structure, an acridine structure, an α-aminoalkylphenone structure, an aminobenzophenone structure, an N-phenylglycine structure, an acylphosphine oxide structure, a benzyl dimethyl ketal structure, an α-hydroxyalkylphenone structure, or the like. The component (E) may be, for example, a compound having a structure selected from the group consisting of an oxime ester structure, an α-aminoalkylphenone structure, and an acylphosphine oxide structure, or may be a compound having an acylphosphine oxide structure.

[0066] Specific examples of the compound having an oxime ester structure include 1-phenyl-1,2-butanedione-2-(o-methoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(o-methoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(o-ethoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-o-benzoyloxime, 1,3-diphenylpropanetrione-2-(o-ethoxycarbonyl)oxime, and 1-phenyl-3-ethoxypropanetrione-2-(o-benzoyl)oxime.

[0067] Specific examples of compounds having an α-aminoalkylphenone structure include 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-morpholinophenyl)-butanone-1, and the like.

[0068] Specific examples of compounds having an acylphosphine oxide structure include bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide.

[0069] The amount of component (E) may be 0.1 to 15 parts by mass, 0.5 to 10 parts by mass, or 1 to 8 parts by mass per 100 parts by mass of the total amount of component (A).

[0070] Component (F): Oxetane Compound The component (F) is a compound having one or more oxetanyl groups. The component (F) may be a compound having no (meth)acryloyl group or epoxy group. The component (F) may be a compound having two or more oxetanyl groups. When the adhesive composition further contains component (F), the refractive index of the cured product of the adhesive composition tends to be further reduced.

[0071] Commercially available products of component (F) include, for example, Aron Oxetane (registered trademark) OXT-101, OXT-211, OXT-213, OXT-212, OXT-121, and OXT-221 (trade names, all manufactured by Toagosei Co., Ltd.).

[0072] The content of component (F) may be 1 mass % or more, 3 mass % or more, or 5 mass % or more, and may be 30 mass % or less, 20 mass % or less, or 10 mass % or less, based on the total amount of the adhesive composition.

[0073] The adhesive composition may contain other components, such as a coupling agent, an antioxidant, and a photosensitizer.

[0074] The coupling agent may be, for example, a silane coupling agent. The silane coupling agent may be, for example, a compound having a hydrolyzable silyl group and a functional group capable of reacting with either a (meth)acrylate compound or an epoxy compound. The hydrolyzable silyl group is, for example, a group having a silicon atom and 1 to 3 alkoxy groups bonded to the silicon atom. The number of carbon atoms in the alkoxy group bonded to the silicon atom may be, for example, 1 to 4. Examples of functional groups include amino groups such as primary amino groups and secondary amino groups, epoxy groups, mercapto groups, and (meth)acryloyl groups. In this specification, compounds having a hydrolyzable silyl group and a (meth)acryloyl group, and compounds having a hydrolyzable silyl group and an epoxy group are classified as silane coupling agents.

[0075] Commercially available silane coupling agents include, for example, KBM-303, KBM-402, KBM-403, KBE-402, KBE-403, KBM-4803, KBM-502, KBM-503, KBE-502, KBE-503, KBM-5103, KBM-5803, KBM-602, KBM-603, KBM-903, KBE-903, KBE-9103P, KBM-573, KBM-575, KBM-802, and KBM-803 (trade names, all manufactured by Shin-Etsu Chemical Co., Ltd.).

[0076] The content of the silane coupling agent may be 0.1 mass % or more, 0.2 mass % or more, or 0.5 mass % or more, and may be 10 mass % or less, 8 mass % or less, 5 mass % or less, 3 mass % or less, or 2 mass % or less, based on the total amount of the adhesive composition.

[0077] Examples of antioxidants include quinone derivatives such as benzoquinone and hydroquinone, phenol derivatives (hindered phenol derivatives) such as 4-methoxyphenol and 4-t-butylcatechol, aminoxyl derivatives such as 2,2,6,6-tetramethylpiperidine-1-oxyl and 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl, and hindered amine derivatives such as tetramethylpiperidyl methacrylate.

[0078] The content of the antioxidant may be 0.1 to 10 mass % based on the total amount of the adhesive composition.

[0079] Examples of photosensitizers include benzoflavin, anthracene, pyrene, thioxanthone, benzophenone, anthraquinone, camphorquinone, coumarin dyes, and oxazole compounds.

[0080] The content of the photosensitizer may be 0.01 to 10% by mass, or may be 0.01 to 1% by mass, based on the total amount of the adhesive composition.

[0081] The adhesive composition can be prepared by mixing (or kneading) the components (A), (B), (C), and (D), as well as the component (E) and other components. Mixing can be carried out using an appropriate combination of a conventional mixer and a dispersing machine such as a planetary mixer. During mixing, degassing treatment, such as vacuum degassing, may be performed as appropriate.

[0082] The adhesive composition can form an adhesive part (adhesive layer) that has excellent adhesion to various adherends. The adhesive part can be obtained by forming an adhesive part precursor by placing the adhesive composition at a predetermined position and irradiating the placed adhesive part precursor with light. The light irradiation may be performed while heating. The adhesive part contains a cured product of the adhesive composition. The light irradiation may be performed directly on the adhesive composition or may be performed via a transparent resin, glass, or the like.

[0083] The light for irradiation may be light having a wavelength in the range of 150 to 750 nm or light having a wavelength in the range of 254 to 405 nm, or may be ultraviolet light.

[0084] Examples of light sources for light irradiation include low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, metal halide lamps, and LED light sources. The integrated light amount of light irradiation can be appropriately set, for example, from 100 to 5000 mJ / cm. ２ It may be.

[0085] The atmosphere for light irradiation is not particularly limited, but may be, for example, an air atmosphere or an inert gas atmosphere such as nitrogen or argon.

[0086] When light irradiation is performed while heating, the heating conditions may be, for example, 60 to 150°C.

[0087] After the adhesive precursor is irradiated with light, it may be further subjected to a heat treatment, for example, at a heating temperature of 60 to 180° C. for a holding time of 5 to 60 minutes.

[0088] The infrared transmittance of the cured product of the adhesive composition may be 70% or more, 75% or more, 80% or more, 85% or more, or 90% or more. The infrared transmittance can be determined by measuring the transmittance at a wavelength of 1310 nm using a spectrophotometer. A measurement sample can be prepared by the following procedure. First, a 500 μm thick spacer film is placed on a release film so that the dimensions are 50 mm wide x 50 mm long and 500 μm thick, and the adhesive composition is applied to the release film. Next, an LED lamp (manufactured by Ushio Inc., wavelength: 365 nm) is used to illuminate the cured product at 30 mW / cm. ２ The adhesive composition is irradiated with light for 30 seconds, and 600 seconds after the end of the light irradiation, the adhesive composition is peeled off from the release film to obtain a measurement sample. In addition, glass used as the substrate can be used as a baseline.

[0089] [Adhesive] In one embodiment, the adhesive comprises a first adherend, a second adherend, and an adhesive joint that bonds the first adherend and the second adherend to each other. The adhesive joint contains a cured product of the adhesive composition described above.

[0090] Examples of the first and second adherends include organic materials such as polyolefin resins, polyamide resins, ABS (acrylonitrile butadiene styrene) resins, PC (polycarbonate) resins, PET (polyethylene terephthalate) resins, PPS (polyphenylene sulfide) resins, acrylic resins, and transparent resins; inorganic materials such as steel, stainless steel, metals (aluminum, copper, nickel, chromium, etc.) or alloys of these metals, glass, and silicon wafers; wood; and rubber. Examples of the first and second adherends 1 and 2 include composites of the above-mentioned plastics and inorganic materials. Either the first or second adherend 1 or 2 may be a transparent resin or glass from the viewpoint of light irradiation.

[0091] The thickness of the first adherend and the second adherend may be, for example, 0.1 to 2.0 mm, 0.1 to 1.0 mm, or 0.1 to 0.5 mm.

[0092] The adhesive can be obtained, for example, by a method including the steps of applying an adhesive composition onto a first adherend to form an adhesive precursor containing the adhesive composition, placing a second adherend on the adhesive precursor to produce a laminate, and irradiating the adhesive precursor of the laminate with light to form an adhesive containing a cured product of the adhesive composition.

[0093] The adhesive composition can be applied using a knife coater, a roll coater, an applicator, a comma coater, a die coater, a dispenser, or the like.

[0094] The light irradiation conditions (light wavelength, light source, integrated light amount, etc.) for the adhesive portion precursor of the laminate may be the same as the light irradiation conditions (light wavelength, light source, integrated light amount, etc.) described above.

[0095] The adhesive portion precursor of the laminate may be irradiated with light while being heated. The heating conditions (heating temperature, etc.) may be the same as those described above.

[0096] After the adhesive precursor of the laminate is irradiated with light, the adhesive precursor may be further subjected to a heat treatment. The heat treatment conditions (heating temperature, holding time, etc.) may be the same as those described above.

[0097] The thickness of the adhesive joint containing the cured product of the adhesive composition may be, for example, 0.01 to 1.0 mm, 0.01 to 0.5 mm, or 0.01 to 0.2 mm.

[0098] The present disclosure will be specifically described below using examples, but the present disclosure is not limited to these examples.

[0099] [Synthesis of (meth)acrylic resin (crosslinking agent)] The following raw materials were prepared. (Meth)acrylate compounds M-3F: trifluoroethyl methacrylate (Light Ester M-3F, manufactured by Kyoeisha Chemical Co., Ltd.) TTA-15: 3,4-epoxycyclohexylmethyl methacrylate (manufactured by Sun Chemical Co., Ltd.) BA: butyl acrylate (manufactured by Toagosei Co., Ltd.) MMA: methyl methacrylate (Acryester M, manufactured by Mitsubishi Chemical Corporation) GMA: glycidyl methacrylate (manufactured by Mitsubishi Gas Chemical Company, Inc.) Thermal radical generator V-601: dimethyl-2,2'-azobis(2-methylpropionate) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) Solvent NPG(D): neopentyl glycol diglycidyl ether (Epogose (registered trademark) NPG(D)) (manufactured by Yokkaichi Synthetic Co., Ltd.)

[0100] <Production Example 1> 84.06 g of M-3F and 98.12 g of TTA-15 (molar ratio of M-3F / TTA-15 = 50% / 50%), 10.17 g of V-601, and 23.72 g of NPG (D) were mixed to prepare a mixture (a-1). Separately, 1.82 g of V-601 was dissolved in 7.29 g of NPG (D) to prepare a solution (b-1).

[0101] A flask equipped with a stirrer, dropping funnel, condenser, thermometer, and gas inlet tube was charged with 163.2 g of NPG (D), and the mixture was stirred under a nitrogen atmosphere while replacing the gas, and the temperature was raised to 85°C. Next, mixture (a-1) was added dropwise to the flask over 2 hours. After the dropwise addition was completed, the mixture was stirred at 85°C for 20 minutes, after which solution (b-1) was added and stirred for an additional 7 hours. Next, with continued stirring, the mixture was cooled to room temperature (25°C) to obtain a solution containing the (meth)acrylic resin (crosslinking agent A) of Production Example 1. The solids concentration was 50% by mass. The solids content of the (meth)acrylic resin-containing solution refers to the components other than the solvent of the (meth)acrylic resin-containing solution.

[0102] Preparation Example 2: 144.38 g of M-3F and 42.13 g of TTA-15 (molar ratio of M-3F / TTA-15=80% / 20%), 5.78 g of V-601, and 24.11 g of NPG (D) were mixed to prepare a mixture (a-2). Separately, 1.87 g of V-601 was dissolved in 7.46 g of NPG (D) to prepare a solution (b-2).

[0103] A flask equipped with a stirrer, dropping funnel, condenser, thermometer, and gas inlet tube was charged with 162.44 g of NPG (D), and the mixture was stirred under a nitrogen atmosphere while replacing the gas, and the temperature was raised to 85°C. Next, mixture (a-2) was added dropwise to the flask over 2 hours. After the dropwise addition was completed, the mixture was stirred at 85°C for 20 minutes, and then solution (b-2) was added and stirred for an additional 7 hours. Next, with continued stirring, the mixture was cooled to room temperature (25°C) to obtain a solution containing the (meth)acrylic resin (crosslinking agent B) of Production Example 2. The solids concentration was 50% by mass.

[0104] Comparative Production Example 1 Mixture (a-3) was prepared by mixing 182.17 g of M-3F (molar ratio of M-3F / TTA-15=100% / 0%), 10.17 g of V-601, and 23.72 g of NPG (D). A solution containing the (meth)acrylic resin (crosslinking agent a) of Comparative Production Example 1 was obtained by the same procedure as in Production Example 1, except that mixture (a-1) was replaced with mixture (a-3).

[0105] Comparative Production Example 2 95.41 g of BA, 82.81 g of MMA, and 11.76 g of GMA (molar ratio of BA / MMA / GMA=45% / 50% / 5%), 2.28 g of V-601, and 24.42 g of NPG (D) were mixed to prepare a mixture (a-4). A solution containing the (meth)acrylic resin (crosslinking agent b) of Comparative Production Example 2 was obtained by the same procedure as in Production Example 2, except that mixture (a-2) was changed to mixture (a-4).

[0106] [Evaluation of (meth)acrylic resin (crosslinking agent)] (Measurement of viscosity (25°C)) The viscosity of a solution containing a (meth)acrylic resin at 25°C was measured at a rotation speed of 10 rpm after setting a sample volume of 0.5 to 1.0 mL in an E-type viscometer (manufactured by Toki Sangyo Co., Ltd., product name: VISCOMETER-TV22, applicable cone-plate rotor: 3° × R17.65). The results are shown in Table 1.

[0107] (Measurement of weight average molecular weight (Mw)) A solution containing a (meth)acrylic resin was dissolved in tetrahydrofuran (THF) to prepare a 0.2 mass % THF solution as a sample for Mw measurement. Mw was measured by gel permeation chromatography (GPC) and calculated by conversion using a calibration curve of standard polystyrene. The GPC conditions are shown below. The results are also shown in Table 1. Measuring apparatus: Shodex (registered trademark) GPC-101 (manufactured by Resonac Co., Ltd.) Detector: Differential refractometer Shodex RI-71S (manufactured by Resonac Co., Ltd.) Column: Shodex LF-804 + LF-804 (manufactured by Resonac Co., Ltd.) Column temperature: 40°C Eluent: tetrahydrofuran (THF) Flow rate: 1 mL / min

[0108]

[0109] [Preparation of Adhesive Compositions] <Examples 1 to 15 and Comparative Examples 1 to 4> The adhesive compositions of Examples 1 to 15 and Comparative Examples 1 to 4 containing component (A), component (B), component (C), and component (D) were prepared by mixing the components (unit: parts by mass) shown in Tables 2 and 3 in a planetary mixer (5 minutes / 1500 rpm).

[0110] The details of each raw material are as follows: (Meth)acrylate compounds V-13F: 1H,1H,2H,2H-tridecafluorooctyl acrylate (2-(perfluorohexyl)ethyl acrylate) (manufactured by Osaka Organic Chemical Industry Ltd.) M-3F: trifluoroethyl methacrylate (Light Ester M-3F, manufactured by Kyoeisha Chemical Co., Ltd.) 4-HBA: 4-hydroxybutyl acrylate (manufactured by Osaka Organic Chemical Industry Ltd.) 2-MTA: 2-methoxyethyl acrylate (manufactured by Osaka Organic Chemical Industry Ltd.) Epoxy compounds NPG(D): neopentyl glycol diglycidyl ether (Epogose (registered trademark) NPG(D)) (manufactured by Yokkaichi Chemical Co., Ltd.) HD(D): 1,6-hexanediol diglycidyl ether (Epogose (registered trademark) HD(D)) (manufactured by Yokkaichi Chemical Co., Ltd.) EHPE3150: 1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol (manufactured by Daicel Corporation) 2021P: 3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (Celloxide (registered trademark) 2021P, manufactured by Daicel Corporation) BisF: bisphenol F type epoxy resin (EPICLON (registered trademark) 830, manufactured by DIC Corporation, liquid at 25°C) Oxetane compounds OXT-221: 3-ethyl-3-{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane (Aronoxetane (registered trademark) OXT-221, manufactured by Toagosei Co., Ltd.) OXT-121: 1,4-bis{[(3-ethyloxetan-3-yl)methoxy]methyl}benzene (Aron Oxetane (registered trademark) OXT-121, manufactured by Toagosei Co., Ltd.) Crosslinking agent (meth)acrylic resins of Production Examples 1 and 2 and Comparative Production Examples 1 and 2 (crosslinking agents A, B, and a, b) Photoacid generator CPI-110P: sulfonium salt (manufactured by San-Apro Co., Ltd.) CPI-210S: sulfonium salt (manufactured by San-Apro Co., Ltd.)

[0111] The amounts of the (meth)acrylic resins (crosslinking agents A, B, and a, b) of Production Examples 1 and 2 and Comparative Production Examples 1 and 2, which serve as crosslinking agents, and NPG (D), which serves as an epoxy compound, added were prepared using the solution containing the (meth)acrylic resin (crosslinking agent) obtained above.

[0112] [Evaluation of adhesive composition] (Appearance evaluation) After preparing the adhesive composition, it was left to stand at room temperature (25°C) for 30 minutes and visually inspected for the presence or absence of turbidity and precipitates. When no turbidity or precipitates were observed, it was evaluated as "A", and when turbidity or precipitates were observed, it was evaluated as "B". The results are shown in Tables 2 and 3.

[0113] (Measurement of refractive index) The refractive index of the adhesive composition at room temperature (25°C) was measured using an Abbemat 300 (manufactured by Anton Paar, wavelength: 589 nm) so that the sample volume was 0.1 to 0.2 mL. The results are shown in Tables 2 and 3.

[0114] (Measurement of Shear Strength) A 50 μm thick spacer film was placed on a glass slide to have dimensions of 5 mm wide x 5 mm thick x 50 μm thick, and the adhesive composition was applied to the glass slide. A glass chip with a width of 7 mm x 7 mm and a thickness of 1.0 mm was placed on the applied adhesive composition, and an LED lamp (manufactured by Ushio Inc., wavelength: 365 nm) was used to measure the shear strength at 30 mW / cm. ２ The adhesive composition was irradiated with light for 30 seconds. The shear strength was measured using a bond tester (Nordson, product name: DAGE4000) at a shear rate of 180 mm / min, using a measurement sample taken 270 seconds after the end of light irradiation. The results are shown in Tables 2 and 3.

[0115] (Measurement of infrared transmittance) The infrared transmittance of the cured adhesive composition was measured at a wavelength of 1,310 nm using a spectrophotometer (manufactured by Agilent Technologies, product name: Cary 7000). Measurement samples were prepared by the following procedure. First, a 500 μm thick spacer film was placed on a release film so that the dimensions were 50 mm wide x 50 mm long and 500 μm thick, and the adhesive composition was applied onto the release film. Next, an LED lamp (manufactured by Ushio Inc., wavelength: 365 nm) was used to measure the infrared transmittance at 30 mW / cm. ２ The adhesive composition was irradiated with light for 30 seconds, and 600 seconds after the end of the light irradiation, the adhesive composition was peeled off from the release film to prepare a measurement sample. The glass substrate was used as a baseline. The results are shown in Tables 2 and 3.

[0116]

[0117]

[0118] As shown in Tables 2 and 3, the adhesive compositions of Examples 1 to 15 had higher shear strength and higher infrared transmittance in the cured products than the adhesive compositions of Comparative Examples 1 to 4. These results confirm that the adhesive composition of the present disclosure, when used with a (meth)acrylate having a fluorine-containing organic group, is capable of providing a cured product having sufficient adhesive strength and high infrared transmittance.

Claims

1. It contains a (meth)acrylate compound, an epoxy compound, a crosslinking agent, and a photoacid generator. The (meth)acrylate compound includes a (meth)acrylate having a fluorine-containing organic group, The crosslinking agent comprises a (meth)acrylic resin having a first structural unit derived from a (meth)acrylate having a fluorine-containing organic group, and a second structural unit derived from a (meth)acrylate having a cyclic ether group. Adhesive composition.

2. The content of the first structural unit is 10 to 90 mol%, based on the total structural units of the (meth)acrylic resin. The content of the second structural unit is 10 to 90 mol%, based on the total structural units of the (meth)acrylic resin. The adhesive composition according to claim 1.

3. The epoxy compound includes an aliphatic epoxy compound. The adhesive composition according to claim 1.

4. The epoxy compound further comprises an alicyclic epoxy compound. The adhesive composition according to claim 3.

5. Further containing an oxetane compound, The adhesive composition according to claim 1.

6. It comprises a first adherend, a second adherend, and an adhesive portion that adheres the first adherend and the second adherend to each other. The adhesive portion contains a cured product of the adhesive composition described in any one of claims 1 to 5. Adhesive body.

7. A (meth)acrylic resin comprising a first structural unit derived from a (meth)acrylate having a fluorine-containing organic group, and a second structural unit derived from a (meth)acrylate having a cyclic ether group, Crosslinking agent.

8. The content of the first structural unit is 10 to 90 mol%, based on the total structural units of the (meth)acrylic resin. The content of the second structural unit is 10 to 90 mol%, based on the total structural units of the (meth)acrylic resin. The crosslinking agent according to claim 7.

9. The (meth)acrylate having a fluorine-containing organic group is a (meth)acrylate having a fluoroalkyl group. The crosslinking agent according to claim 7 or 8.

10. The proportion of fluorine atoms in the fluoroalkyl group of the (meth)acrylate having the fluoroalkyl group is 80% or less, based on the total amount of hydrogen atoms and fluorine atoms directly bonded to the carbon atoms constituting the fluoroalkyl group. The crosslinking agent according to claim 9.

11. The (meth)acrylate having a cyclic ether group is at least one selected from the group consisting of (meth)acrylates having an epoxy group and (meth)acrylates having an oxetanyl group. The crosslinking agent according to claim 7 or 8.

12. The (meth)acrylate having a cyclic ether group is a (meth)acrylate having an alicyclic epoxy group. The crosslinking agent according to claim 7 or 8.

13. The weight-average molecular weight of the (meth)acrylic resin is 10,000 to 60,000. The crosslinking agent according to claim 7 or 8.