Radiation-curable adhesive composition

Abstract

The present invention provides a radiation-curable adhesive composition comprising: (A) at least one cationically polymerizable component; (B) at least one photoinitiator system comprising (B1) at least one ferrocenium salt and (B2) at least one aromatic iodonium salt; (C) at least one peroxide; and (D) optionally at least one free-radically polymerizable compound; wherein the weight ratio of component (B2) to component (B1) is from 0.25 to less than 4, and the weight ratio of component (C) to component (B1) is from 0.5 to 8.

Description

[Technical Field]

[0001] The present invention relates to a radiation-curable adhesive composition, particularly a radiation-curable adhesive composition that can be cured by radiation transmitted through a polymer film and that exhibits excellent adhesive strength when cured, and uses thereof. [Background technology]

[0002] Radiation-curable adhesive compositions are widely used in the semiconductor and electronics fields due to their high curing efficiency, excellent storage stability, energy saving, and applicability to heat-sensitive electronic components and modules. LEDs are semiconductor devices that utilize the phenomenon of electroluminescence to generate light for curing radiation-curable adhesive compositions. Currently, LED light sources generally emit light in the wavelength range of 300 to 475 nm, with typical peak spectral outputs of 365 nm, 390 nm, 395 nm, 405 nm, 415 nm, and 450 nm.

[0003] Advances in electronics technology continue worldwide as manufacturers strive to develop lighter, thinner, and more flexible electronic devices. As a result, polymer film materials, such as polyimide (PI) films, have played an important role in the electronics field due to their excellent properties, such as excellent thermal stability, chemical resistance, and dielectric properties. However, such polymer films block most light. For example, the maximum transmittance of PI films is only 0.08% at wavelengths below 400 nm. Therefore, radiation with wavelengths above 400 nm is required to activate the curing of radiation-curable adhesive compositions underneath the polymer film. However, diaromatic iodonium salts, which serve as cationic photoinitiators in radiation-curable adhesive compositions, can only be activated by radiation with wavelengths below 365 nm unless an appropriate sensitizer selected from anthracene, perylene, phenothiazine, xanthone, thioxanthone, benzophenone, ethyl-4-dimethylaminobenzoate, or sterically hindered amines is added. This sensitizer significantly affects the strength of the cured radiation-curable adhesive composition.

[0004] US 2022 / 0064367 A1 discloses a radiation-curable adhesive composition comprising at least one cationically polymerizable component, a first photoinitiator that releases an acid when irradiated with actinic radiation at a first wavelength λ1, and a second photoinitiator that releases an acid when irradiated with actinic radiation at a second wavelength λ2, the second wavelength λ2 being shorter than the first wavelength λ1, and the second photoinitiator exhibiting sufficient absorption of actinic radiation at the second wavelength λ2 to activate the second photoinitiator in the composition and cure the composition after irradiation of the composition with actinic radiation at the first wavelength λ1. The composition can be activated by sequential irradiation with light at different wavelengths. However, this process requires two light sources and two curing steps to achieve complete cure.

[0005] CN105273167A discloses the use of ferrocenium salts as sensitizers for the photopolymerization of cationically curable compositions using iodonium salt-based polymerization initiators. The ferrocenium salts are used stoichiometrically to enable initiation of polymerization by the iodonium initiator under visible light irradiation. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] US Patent Application Publication No. 2022 / 0064367 [Patent Document 2] Chinese Patent Application Publication No. 105273167 Summary of the Invention [Problem to be solved by the invention]

[0007] None of the above prior art techniques suggest how to solve the problem of incomplete curing due to light loss when the composition is underneath a polymer film, while at the same time producing a cured product with high adhesive strength. To achieve complete cure of radiation-curable compositions, thermal curing and moisture are the current approaches. However, the thermal curing method requires high temperatures (above 60°C), making it inapplicable to temperature-sensitive devices. The moisture curing method typically requires 3 to 7 days to achieve complete cure, which is time-consuming.

[0008] In view of the above, there remains a need for radiation-curable adhesive compositions that can be cured by radiation that penetrates polymer films and that exhibit excellent adhesive strength upon curing. [Means for solving the problem]

[0009] Summary of the Invention According to a first aspect of the present invention, the present specification provides a method for manufacturing a semiconductor device comprising: (A) at least one cationically polymerizable compound (B) at least one photoinitiator system comprising (B1) at least one ferrocenium salt, and (B2) at least one aromatic iodonium salt; (C) at least one peroxide, and (D) optionally at least one free-radically polymerizable compound; The present invention discloses a radiation-curable adhesive composition comprising the above components, wherein the mass ratio of component (B2) to component (B1) is 0.25 to less than 4, and the mass ratio of component (C) to component (B1) is 0.5 to 8.

[0010] According to a second aspect of the present invention, the present specification provides a connection structure comprising a first member, a second member, and an adhesive sandwiched therebetween, wherein the first member and the second member are independently selected from glass, resin, and metal, and the adhesive is formed by curing the radiation-curable adhesive composition of the present invention.

[0011] According to a third aspect of the present invention, the present disclosure provides a method for producing a soluble polymeric polymer comprising the steps of: (a) providing a radiation curable composition according to the present invention; (b) applying the composition onto a first member; (c) placing a second member on the composition on the first member to form a connection structure; (d) irradiating the connection structure with visible light having a wavelength of 400 nm or more, preferably 400 nm to 500 nm; and (e) optionally, heating the composition on the connecting structure. The present invention provides a method for preparing a connecting structure according to the present invention, comprising:

[0012] According to a fourth aspect of the present invention, the present specification provides an electronic device comprising the connecting structure of the present invention or manufactured using the radiation-curable adhesive composition of the present invention.

[0013] According to a fifth aspect of the present invention, the present specification provides the use of a radiation-curable adhesive composition according to the present invention or a connecting structure according to the present invention in manufacturing an electronic device.

[0014] Other features and aspects of the subject matter are described in greater detail below. DETAILED DESCRIPTION OF THE INVENTION

[0015] Those skilled in the art will appreciate that the present invention is described with respect to exemplary embodiments only and is not intended to limit the broad scope of the present invention. Each embodiment so described may be combined with one or more other embodiments, unless expressly stated otherwise. In particular, any feature indicated as being preferred or advantageous may be combined with one or more other features indicated as being preferred or advantageous.

[0016] Unless otherwise specified, in the context of the present invention, the terms used shall be construed in accordance with the following definitions.

[0017] Unless otherwise specified, as used herein, the terms "a," "an," and "the" include singular and plural references.

[0018] As used herein, the terms "comprising" and "comprises" are synonymous with "including," "includes," or "containing," and "contains," and are inclusive or open-ended and do not exclude additional, unrecited components, elements, or method steps.

[0019] The terms "at least one" or "one or more" used to define a component herein refer to the type of component, not the absolute number of molecules. For example, "one or more polyols" refers to one type of polyol or a mixture of multiple different polyols.

[0020] As used herein, the term "visible light" means light having a wavelength of 400 nm or more, preferably 400 nm to 500 nm.

[0021] As used herein, the terms "crosslinking" or "curing" refer to a polymerization or addition reaction beyond the gel point, which is the point at which the storage modulus G' equals the loss modulus G''.

[0022] As used herein, the term "room temperature" refers to about 20°C to about 25°C, preferably about 25°C.

[0023] Unless otherwise specified, the recitation of numerical endpoints includes all numbers and fractions subsumed within the respective range, as well as the recited endpoints.

[0024] All references cited herein are incorporated by reference in their entirety.

[0025] Unless otherwise specified, molecular weight refers to number average molecular weight (Mn). Unless otherwise specified, all molecular weight data refer to values ​​obtained by gel permeation chromatography (GPC), for example according to DIN 55672.

[0026] Unless otherwise defined, all terms used herein, including technical and scientific terms, have the meaning commonly understood by one of ordinary skill in the art to which this invention belongs.

[0027] In one aspect, the disclosure generally comprises: (A) at least one cationically polymerizable component; (B) at least one photoinitiator system comprising (B1) at least one ferrocenium salt and (B2) at least one aromatic iodonium salt; (C) at least one peroxide, and (D) optionally at least one free-radically polymerizable compound; Including, The radiation-curable adhesive composition has a mass ratio of component (B2) to component (B1) of 0.25 to less than 4, and a mass ratio of component (C) to component (B1) of 0.5 to 8.

[0028] <(A) Cationic Polymerizable Component> According to the present invention, the radiation-curable adhesive composition comprises at least one cationically polymerizable component (A).

[0029] In some embodiments, component (A) can be an epoxy-containing compound. Epoxy-containing compounds are cationically curable, meaning that polymerization and / or crosslinking of epoxy groups and other reactions can be initiated by cations. These compounds can be monomers, oligomers, or polymers, and are sometimes referred to as "resins." Such compounds can have an aliphatic, aromatic, alicyclic, or heterocyclic structure, and they can contain pendant epoxide groups or groups that form part of the alicyclic or heterocyclic system.

[0030] Examples of suitable epoxy-containing compounds include polyglycidyl and poly(methylglycidyl) esters of polycarboxylic acids or poly(oxiranyl) ethers of polyethers. The polycarboxylic acids can be aliphatic, such as glutaric acid or adipic acid; alicyclic, such as tetrahydrophthalic acid; or aromatic, such as phthalic acid, isophthalic acid, trimellitic acid, or pyromellitic acid. The polyether can be poly(tetramethylene oxide).

[0031] Suitable epoxy-containing compounds also include polyglycidyl or poly(methylglycidyl) ethers obtained by reacting a compound having at least one free alcoholic hydroxyl group and / or phenolic hydroxyl group with suitably substituted epichlorohydrin.The alcohol can be, for example, an acyclic alcohol such as ethylene glycol, diethylene glycol, and higher poly(oxyethylene) glycol; an alicyclic alcohol such as 1,3- or 1,4-dihydroxycyclohexane, bis(4-hydroxycyclohexyl)methane, 2,2-bis(4-hydroxycyclohexyl)propane, or 1,1-bis(hydroxymethyl)cyclohex-3-ene; or it can contain an aromatic nucleus such as N,N-bis(2-hydroxyethyl)aniline or p,p'-bis(2-hydroxyethylamino)diphenylmethane.

[0032] Other suitable epoxy-containing compounds include those that can be derived from monocyclic phenols, such as resorcinol or hydroquinone, or they can be based on polycyclic phenols, such as bis(4-hydroxyphenyl)methane (bisphenol F), 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), or condensation products obtained under acidic conditions between phenols or cresols and formaldehyde, such as phenol novolacs and cresol novolacs.

[0033] Suitable epoxy-containing compounds also include poly(N-glycidyl) compounds, such as those obtained by dehydrochlorination of the reaction product of epichlorohydrin with an amine containing at least two amine hydrogen atoms, such as n-butylamine, aniline, toluidine, m-xylylenediamine, bis(4-aminophenyl)methane, or bis(4-methylaminophenyl)methane. Suitable poly(N-glycidyl) compounds also include N,N'-diglycidyl derivatives of cycloalkylene ureas, such as ethylene urea or 1,3-propylene urea, as well as N,N'-diglycidyl derivatives of hydantoins, such as 5,5-dimethylhydantoin.

[0034] Examples of suitable epoxy-containing compounds include poly(S-glycidyl) compounds, which are di-S-glycidyl derivatives derived from dithiols such as ethane-1,2-dithiol or bis(4-mercaptomethylphenyl) ether.

[0035] However, it is also possible to use epoxy resins in which the 1,2-epoxy groups are bonded to different heteroatoms or functional groups, such as N,N,O-triglycidyl derivatives of 4-aminophenol, glycidyl ether glycidyl esters of salicylic acid, N-glycidyl-N'-(2-glycidyloxypropyl)-5,5-dimethylhydantoin, or 2-glycidyloxy-1,3-bis(5,5-dimethyl-1-glycidylhydantoin-3-yl)propane.

[0036] Preferred epoxy-containing compounds are cycloaliphatic epoxy resins selected from 3-cyclohexenylmethyl-3-cyclohexylcarboxylate diepoxide, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 3,4-epoxy-6-methyl-cyclohexylmethyl-3,4-epoxy-6-methylcyclohexanecarboxylate, 2,2-bis(4-hydroxycyclohexyl)propane diglycidyl ether, di(3,4-epoxycyclohexylmethyl)hexanedioate, di(3,4-epoxy-6-methylcyclohexylmethyl)hexanedioate, ethylene bis(3,4-epoxycyclohexanecarboxylate), ethanediol di(3,4-epoxycyclohexylmethyl)ether, 2-(3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy)cyclohexane-1,3-dioxane, and combinations thereof.

[0037] Representative examples of alicyclic epoxy resins include those represented by the formulas (I) to (V): [ka] Examples include those represented by the following formula:

[0038] The epoxy compound preferably contains at least one cyclohexene oxide structure, more preferably at least two cyclohexene oxide structures.

[0039] The epoxy-containing compounds can have a very wide range of molecular weights. In general, the epoxy equivalent weight, i.e., the number average molecular weight divided by the number of reactive epoxy groups, is preferably in the range of 60 to 1000.

[0040] Suitable commercially available epoxy-containing compounds for use as component (A) include CELLOXIDE™ 2021 P and CELLOXIDE™ 8000 from Daicel Corporation; EPIKOTE™ RESIN 828 LVEL, EPIKOTE™ RESIN 166 and EPIKOTE™ RESIN 169 from Momentive Specialty Chemicals BV, The Netherlands; Epilox™ resins in product series A, T and AF from Leuna Harze, Germany; or EPICLON™ 840, 840-S, 850, 850-S, EXA8SOCRP, 850-LC from DIC KK, Japan; Omnilane 1005 and Omnilane 2005 from 1GM Resins BV; Syna Epoxy 21 and Syna Epoxy 06 from Synasia Inc.; and Jiangsu Tetra New Material Technology. The products are available under the trade names TTA21, TTA26, TTA60 and TTA128 from Co. Ltd.

[0041] Other cationically polymerizable components that can be used in the compositions of the present invention include, for example, cyclic ether compounds, cyclic lactone compounds, cyclic acetal compounds, cyclic thioether compounds, spiroorthoester compounds, and oxetane compounds.

[0042] It is of course also possible to use mixtures of cationically polymerizable components in the compositions according to the invention.

[0043] Particularly preferably, component (A) may be present in an amount of 2% to 99% by weight, preferably 5% to 95% by weight, based on the total weight of the adhesive composition.

[0044] <(B) Photopolymerization initiator> According to the present invention, the radiation-curable adhesive composition comprises at least one photoinitiator system comprising (B1) at least one ferrocenium salt and (B2) at least one aromatic iodonium salt, wherein the weight ratio of component (B2) to component (B1) is from 0.25 to less than 4. The photoinitiator system is capable of generating cationic active species upon exposure to visible light in the presence of component (C) a peroxide as described herein.

[0045] Examples of suitable ferrocenium salts (B1) are selected from cumenylcyclopentadienyliron(II) hexafluorophosphate, cumenylcyclopentadienyliron(II) hexafluoroantimonate, naphthalenylcyclopentadienyliron(II) hexafluorophosphate, benzylcyclopentadienyliron(II) hexafluorophosphate and cyclopentadienylcarbazoleiron(II) hexafluorophosphate, and combinations thereof.

[0046] The aromatic iodonium salt (B2) used in the present invention is A + B - where A + is an aromatic iodonium ion, of the formula: Ar 1 -I + -Ar 2 It can be expressed as:

[0047] I + Group Ar bonded to 1 and Ar 2 each independently represents an optionally substituted aromatic group, preferably a phenyl group; and the anion B - is HSO4 - , PF6 - , SbF6 - , AsF6- , Cl - , Br - , ClO4 - , PO4 - , SO3CF3 - , aluminate, or borate anions, preferably BF4 - , B(C6F5)4 - , B(C6F4OCF3)4 - , B(C6F4CF3)4 - and combinations thereof.

[0048] In a preferred embodiment, component (B2) is represented by the following formulas (VI) to (XI): [ka] The diaryliodonium salt may be represented by the formula:

[0049] Examples of suitable iodonium salts (B2) are [4-(isooctyloxy)phenyl]2-pyrazolyliodonium hexafluoroantimonate; [4-(2-ethylhexyloxy)phenyl]phenyliodonium hexafluoroantimonate; [4-(2-methylpentoxy)phenyl]phenyliodonium tetrafluoroborate; [4-(3-methylpentoxy)phenyl]phenyliodonium hexafluorophosphate; [4-(4-methylpentoxy)phenyl]phenyliodonium hexafluoroantimonate; [4-(2-propylpentoxy)phenyl]phenyliodonium hexafluoroantimonate; [4-(2 [4-(2-ethylhexyloxy)phenyl]-2-thienyliodonium hexafluorophosphate, [4-(2-ethylhexyloxy)phenyl]-2-furanyliodonium hexafluoroantimonate, tolylcumyliodonium tetrakispentafluorophenylborate, and combinations thereof. Many more examples are disclosed in, for example, U.S. Patent Nos. 3,565,906, 3,712,920, 3,759,989, and 3,763,187.

[0050] According to the present invention, a combination of at least one ferrocenium salt (B1) and at least one aromatic iodonium salt (B2) serves as a photoinitiator in a radiation-curable adhesive composition, and the mass ratio of component (B2) to component (B1) is from 0.25 to less than 4, preferably from 0.25 to 3, more preferably from 0.25 to 2, and even more preferably from 0.5 to 1.8. If the mass ratio of component (B2) to component (B1) is less than 0.25 or is 4 or greater, the adhesive strength of the cured radiation-curable adhesive composition is insufficient for practical use.

[0051] In a preferred embodiment, component (B) does not contain any aryl sulfonium salts.

[0052] Suitable commercially available components (B1) are sold as R-Gen™ 261 and R-Gen™ 262 by Chitec Technology.

[0053] Suitable commercially available components (B2) are sold as UV1242 and UV2257 by Deuteron and as BLUESIL™ PI 2074 by Bluestar.

[0054] Particularly preferably, component (B1) may be present in an amount of 0.01% to 8% by weight, preferably 0.2% to 5% by weight, based on the total weight of the adhesive composition.

[0055] Particularly preferably, component (B2) may be present in an amount of 0.01% to 8% by weight, preferably 0.2% to 5% by weight, based on the total weight of the adhesive composition.

[0056] <(C) Peroxide> According to the invention, the radiation-curable adhesive composition comprises at least one peroxide (C), which acts as an accelerator for curing the composition by cationic polymerization.

[0057] Peroxides, as described herein, refer to compounds that have an -OO- bond that can be easily broken to generate free radicals.

[0058] In some embodiments, the peroxides used in the present invention do not contain any acyl groups. Suitable examples of peroxides that do not contain acyl groups include cumene hydroperoxide and di-tert-butyl peroxide (DTBP).

[0059] In most cases, the peroxides (C) used in the present invention have at least one acyl group and can be chosen from peracids, acyl peroxides without ester groups, peroxyesters and peroxycarbonate type compounds.

[0060] Peracids, as described herein, are compounds having the general formula R-CH(=O)O-OH, where R is an alkyl or aryl group.

[0061] The ester-free acyl peroxides described herein are compounds having the general formula R1-CH(=O)-OO-CH(=O)-R2, where R1 and R2 represent alkyl and / or aryl groups. Suitable examples include benzoyl peroxide (BPO), dilauryl peroxide, etc.

[0062] The peroxycarbonate-type compounds described herein may be esters of monoperoxycarboxylic acids and / or esters of diperoxycarboxylic acids. Esters of monoperoxycarboxylic acids may have the general formula R3-O-CH(=O)-OO-R4, where R3 and R4 are independently selected from linear alkyl groups, branched alkyl groups, cycloalkyl groups, and hydroxyalkyl groups. Esters of diperoxycarboxylic acids may have the general formula R5-O-CH(=O)-OO-CH(=O)-O-R6, where R5 and R6 are independently selected from linear alkyl groups, branched alkyl groups, cycloalkyl groups, and hydroxyalkyl groups. Suitable examples include di(4-tert-butylcyclohexyl)-peroxydicarbonate.

[0063] Preferably, peroxyesters are used in the present invention. The peroxyesters described herein are compounds having the general formula R7-CH(=O)-OO-R8, where R7 and R8 are independently selected from linear alkyl groups, branched alkyl groups, cycloalkyl groups, and hydroxyalkyl groups. In particular, peroxyesters containing aryl groups are not suitable for use in the present invention. Suitable examples of peroxyesters include tertiary butylperoxy-2-ethylhexanoate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, etc.

[0064] In a particularly preferred embodiment, peroxyesters having at least two functional groups are used in the present invention. Such compounds have the general formula R-CH(=O)-OOR 10 -OO-CH(=O)-R 11 (In the formula, R9, R 10 , R 11 are independently selected from linear alkyl groups, branched chain alkyl groups, cycloalkyl groups, and hydroxyalkyl groups, and are preferably C1 to C15 linear alkyl groups and branched chain alkyl groups. Suitable examples include 2,5-dimethyl-2,5-di-(2-ethylhexanoyl-peroxy)hexane.

[0065] According to the present invention, the weight ratio of the peroxide (C) to the ferrocenium salt (B1) is 0.5 to 8, preferably 0.5 to 6, more preferably 1 to 6, and particularly preferably 1 to 5. The proportion of peroxide is selected so as to promote the light absorption of the ferrocenium salt and the generation of free radicals according to the present invention. If the weight ratio of the peroxide (C) to the ferrocenium salt (B1) is less than 0.5, the adhesive composition of the present invention cannot be completely cured by radiation transmitted through the polymer film.

[0066] Suitable commercially available peroxides (C) are sold as Trigonox 141, Trigonox 121, Trigonox 26 and Perkadox 16 by AkzoNobel, Luperox 26 by Akema, and Cumene hydroperoxide and Dicumyl peroxide by Sigma-Aldrich.

[0067] Particularly preferably, component (C) may be present in an amount of 0.01% to 7% by weight, preferably 1% to 5% by weight, based on the total weight of the adhesive composition.

[0068] <(D) Free-Radical Polymerizable Compound> According to the present invention, the radiation-curable adhesive composition optionally comprises at least one free-radically polymerizable compound (D).

[0069] The free-radically polymerizable component (D) is a component that undergoes polymerization initiated by free radicals. Useful free-radically polymerizable components are acrylate and methacrylate monomers, oligomers, and / or polymers, which may be monofunctional or polyfunctional materials, i.e., have 1, 2, 3, 4, 5, 6, 7, 8, 9, 10...20...30...40...50...100 or more functional groups polymerizable by a free-radical initiator, and may include aliphatic, aromatic, cycloaliphatic, arylaliphatic, heterocyclic moieties, or any combination thereof. Examples of polyfunctional materials include dendritic polymers, such as dendrimers, linear dendritic polymers, dendrigraft polymers, hyperbranched polymers, star-branched polymers, and hypergraft polymers.

[0070] Examples of free radically polymerizable components include acrylates and methacrylates, such as isobornyl (meth)acrylate, bornyl (meth)acrylate, tricyclodecanyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, 4-butylcyclohexyl (meth)acrylate, acryloylmorpholine, (meth)acrylic acid, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl ... Acrylate, 2-hydroxybutyl (meth)acrylate, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, amyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, caprolactone acrylate, isoamyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, tridecyl (meth)acrylate, undecyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, butoxyethyl (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, benzyl (meth)acrylate, phenoxyethyl (meth) Acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, methoxyethylene glycol (meth)acrylate, ethoxyethyl (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, diacetone (meth)acrylamide, β-carboxyethyl (meth)acrylate, phthalic acid (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate,Examples of suitable acrylates include butylcarbamylethyl (meth)acrylate, n-isopropyl (meth)acrylamide fluorinated (meth)acrylate, and 7-amino-3,7-dimethyloctyl (meth)acrylate.

[0071] Examples of polyfunctional free radical polymerizable components include those having a (meth)acryloyl group, such as trimethylolpropane tri(meth)acrylate, pentaerythritol (meth)acrylate, ethylene glycol di(meth)acrylate, bisphenol A diglycidyl ether di(meth)acrylate, dicyclopentadiene dimethanol di(meth)acrylate, [2-[1,1-dimethyl-2-[(1-oxoallyl)oxy]ethyl]-5-ethyl-1,3-dioxan-5-yl]methyl acrylate;Dipentaerythritol monohydroxypenta(meth)acrylate, propoxylated trimethylolpropane tri(meth)acrylate, propoxylated neopentyl glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, polybutanediol di(meth)acrylate, tripropylene glycol di(meth)acrylate, glycerol tri(meth)acrylate, phosphate mono- and di(meth)acrylate, C7-C20 alkyl di(meth)acrylate, tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate, tris(2-hydroxyethyl)isocyanurate di(meth)acrylate, pentaerythritol Examples of suitable esters include ethoxylated and / or propoxylated bisphenol A diols, such as bisphenol A, bisphenol A diols, and diglycidyl ethers, diacrylates of polyoxyalkylated bisphenol A, and epoxy (meth)acrylates, which are (meth)acrylate adducts of triethylene glycol divinyl ether to bisphenol A, and hydroxyethyl acrylate adducts.

[0072] According to one embodiment, the radically polymerizable component is a multifunctional (meth)acrylate, which may contain all methacryloyl groups, all acryloyl groups, or any combination of methacryloyl and acryloyl groups. In one embodiment, the free radically polymerizable component is selected from the group consisting of bisphenol A diglycidyl ether di(meth)acrylate, ethoxylated or propoxylated bisphenol A or bisphenol F di(meth)acrylate, dicyclopentadiene dimethanol di(meth)acrylate, [2-[1,1-dimethyl-2-[(1-oxoallyl)oxy]ethyl]-5-ethyl-1,3-dioxan-5-yl]methyl acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, propoxylated trimethylolpropane tri(meth)acrylate, and propoxylated neopentyl glycol di(meth)acrylate, and any combination thereof.

[0073] The above radical polymerizable compounds can be used alone or in combination of two or more thereof.

[0074] Examples of commercially available products of component (D) include polyester acrylate (trade name: EBECRYL81O) manufactured by Daicel Allnex Corporation, polyester acrylate (trade name: M7100) manufactured by Toagosei Co., Ltd., tricyclodecane dimethanol diacrylate (trade name: SR833S) manufactured by Sartomer, and diacrylate ester of bisphenol A-type epoxy resin (trade name: Ebecryl3700) manufactured by Allnex.

[0075] Particularly preferably, component (D) may be present in an amount of 0 to 60% by weight, preferably 1 to 50% by weight, based on the total weight of the adhesive composition.

[0076] <(E) Polyol> The radiation-curable adhesive composition may optionally contain at least one polyol (E). Polyols are effective in enhancing the adhesive properties of the resin system of the present invention. Suitable polyols can be selected from polyester polyols and / or polyether polyols, preferably polyester polyols.

[0077] Examples of polyester polyols include condensation polyester polyols, addition polymerization polyester polyols, and polycarbonate polyols. Condensation polyester polyols can be obtained by the condensation reaction of diol compounds such as ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,9-nonanediol, 1,4-hexanedimethanol, dimer acid diol, and polyethylene glycol with organic polybasic acids such as adipic acid, isophthalic acid, terephthalic acid, and sebacic acid, and preferably have a molecular weight of 100 to 100,000. Addition polymerization polyester polyols may contain polycaprolactone, and preferably have a molecular weight of 100 to 100,000. Polycarbonate polyols can be prepared from polyols by direct phosgenation or by transesterification with diphenyl carbonate. The molecular weight is preferably 100 to 100,000.

[0078] Suitable examples of polyester polyols include poly(hexanediol adipate) polyol, poly(butanediol adipate) polyol, poly-epsilon-caprolactone polyol, poly(hexanediol dodecanedioate) polyol, poly(hexanediol terephthalate adipate) polyol, and mixtures thereof.

[0079] Examples of polyether polyols include PEG, PPG, and PTO types. PEG polyols can be obtained by addition polymerization of ethylene oxide using a compound having active hydrogen as a reaction initiator, and their molecular weight is preferably 100 to 100,000. PPG polyols can be obtained by addition polymerization of propylene oxide using a compound having active hydrogen as a reaction initiator, and their molecular weight is preferably 100 to 100,000. PTG polyols can be obtained by cationic polymerization of tetrahydrofuran, and their molecular weight is preferably 100 to 100,000.

[0080] Suitable examples of polyether polyols include polypropanediol, polytetramethylene ether glycol, poly(oxypropylene) glycol, polyethylene oxide, polybutylene oxide, and any of the foregoing end-capped with ethylene oxide. The most preferred polyether polyols are polytetramethylene ether glycol, poly(oxypropylene) glycol, and ethylene oxide end-capped poly(oxypropylene) glycol.

[0081] Examples of commercially available polyols that can be used in the present invention are those available under the trade names ETERNACOLL UM-90(1 / 1), Etemacoll UHCSO Capa 3050, Capa 2200, Capa 3091 from Perstorp, Liquiflex H from Petroflex, Merginol 901 from HOBUM Oleochemicals, Placel 305, Placel CD 205 PL from Deicel Corporation, Priplast 3172, Priplast 3196 from Croda, Kuraray Polyol F-3010, Kuraray Polyol P-6010 from Kuraray Co., Ltd., Krasol LBH-2000, Krasol HLBH-P3000 from Cray Valley, or Hoopol S-1015-35 or Hoopol S-1063-35 from Synthesia International SLU.

[0082] Particularly preferably, component (E) may be present in an amount of 0 to 80% by weight, preferably 1 to 60% by weight, based on the total weight of the adhesive composition.

[0083] <(F) Additives> The compositions of the present invention may further comprise silane coupling agents, fillers, thixotropic agents, pigments, surfactants, preservatives, plasticizers, lubricants, antifoaming agents, and combinations thereof.

[0084] Examples of silane coupling agents include, but are not limited to, 3-aminopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-glycidoxypropyltrimethoxysilane. Suitable commercially available products include SH6062 and SZ6030 available from Toray-Dow Corning Silicone Inc., KB E903 and KBM803 available from Shin-Etsu Silicone Inc., and Sliquest A-187 available from Momentive. The silane coupling agent may be present in an amount of 0 to 15 wt. %, preferably 1 to 10 wt. %, based on the total weight of the adhesive composition.

[0085] Examples of fillers include, but are not limited to, silica, alumina, aluminum nitride, fumed silica, precipitated silica, fumed titanium dioxide, and combinations thereof. A suitable commercially available product is sold as PLV6, available from Tatsumori. The filler may be present in an amount of 0 to 95 wt. %, preferably 1 to 90 wt. %, based on the total weight of the adhesive composition.

[0086] Thixotropic agents can be used to modify the viscosity of the adhesive composition. A suitable thixotropic agent is fumed silica. A commercially available product of fumed silica is available from Cabot as TS720. The thixotropic agent may be present in an amount of 0 to 10 wt. %, preferably 1 to 5 wt. %, based on the total weight of the adhesive composition.

[0087] In particular, it is preferred that the composition of the present invention does not contain any sensitizer selected from anthracene, perylene, phenothiazine, xanthone, thioxanthone, benzophenone, ethyl-4 dimethylaminobenzoate or sterically hindered amines.

[0088] <Adhesive composition> In a particularly preferred embodiment, the radiation curable adhesive composition comprises, based on the total weight of the adhesive composition: 2 to 99 wt. %, preferably 5 to 95 wt. %, of at least one cationically polymerizable component; 0.01 to 8% by weight, preferably 0.2 to 5% by weight, of at least one ferrocenium salt, 0.01 to 8% by weight, preferably 0.2 to 5% by weight, of at least one aromatic iodonium salt, 0.01 to 7% by weight, preferably 1 to 5% by weight, of at least one peroxide, 0 to 60 wt. %, preferably 1 to 50 wt. %, of at least one free-radically polymerizable compound, 0 to 80% by weight, preferably 1 to 60% by weight, of at least one polyol, 0 to 15 wt. %, preferably 1 to 10 wt. %, of at least one silane coupling agent, 0 to 95% by weight, preferably 1 to 90% by weight, of at least one filler, and 0 to 10% by weight, preferably 1 to 5% by weight, of at least one thixotropic agent Includes.

[0089] <Manufacturing method and curing profile> Radiation curable adhesive compositions according to the present invention can be prepared by mixing all of the components according to the present invention, avoiding the use of visible light, until a homogeneous composition is formed.

[0090] The equipment used for mixing, stirring, dispersing, etc. is not particularly limited. Examples of equipment that can be used include an automatic mortar equipped with a stirrer or heater, a Henschel mixer, a three-roll mill, a ball mill, a planetary mixer, and a bead mill. These equipment may also be used in appropriate combination. The method for preparing the radiation-curable adhesive composition is not particularly limited, as long as the composition contains the above components mixed uniformly.

[0091] According to the present invention, the radiation-curable adhesive composition can be cured by visible light transmitted through the polymer film, where the visible light has a wavelength of 400 nm or more, preferably 400 nm to 500 nm.

[0092] In a preferred embodiment, the radiation-curable adhesive composition is curable in one step by visible light transmitted through the polymer film, where the visible light has a wavelength of 400 nm or greater, preferably 400 nm to 500 nm.

[0093] In a preferred embodiment, the polymer film can be selected from polyimide films, polycarbonate films, polybutylene terephthalate films and polyamide films, more preferably polyimide films. The polymer film does not need to be in contact with the adhesive composition.

[0094] In a preferred embodiment, the radiation exposure time can be as short as 1 second and as long as 20 minutes, and is preferably from 1 second to 10 minutes.

[0095] Preferably, the light emitting source is an LED light emitting lamp with an emission maximum at 450 nm and an output of 300-500 mW / cm 2 A commercially available LED light emitting lamp having an intensity of is available from UVATA under the trade name UPP10SIF-031.

[0096] According to the present invention, the cured product of the radiation-curable adhesive composition can achieve an adhesive strength of 10 kgf or more based on the dot shear test described herein.

[0097] Of course, different radiation curable adhesive compositions will have different time and temperature cure profiles, and various compositions can be designed to provide cure profiles that are particularly suited to industrial manufacturing processes.

[0098] Connection structure and electronic device According to a second aspect of the present invention, provided herein is a connecting structure comprising a first member, a second member, and an adhesive sandwiched therebetween, wherein the first member and the second member are independently selected from glass, polymer film, and metal, preferably at least one member being a polymer film, and wherein the adhesive is formed by curing a radiation-curable adhesive composition of the present invention.

[0099] In a preferred embodiment, at least one of the components may be selected from resins such as polyimide film, polycarbonate film, polybutylene terephthalate film and polyamide film, more preferably polyimide film.

[0100] The first and / or second members may be single-material and single-layer pieces, or may include multiple layers of the same or different materials. The layers may be continuous or discontinuous.

[0101] The first and / or second members may be of various shapes, sizes, or complex structures, and in such circumstances, the adhesive sandwiched therebetween may only contact a portion of the first and / or second members.

[0102] In one particular embodiment, a radiation-curable adhesive composition according to the present invention is poured into a first component covered with a mold, then a second component is placed in the mold, the composition is cured, and the mold is then removed.

[0103] The components of the articles described herein can have a variety of properties, including rigidity (e.g., a hard component, i.e., a component that cannot be bent using two hands or that breaks when an attempt is made to bend it using two hands), flexibility (e.g., a soft component, i.e., a component that can be bent with less than two hands), porosity, electrical conductivity, lack of electrical conductivity, and combinations thereof, preferably a soft component.

[0104] The components of the article can be in a variety of forms including, for example, fibers, yarns, yarns, woven fabrics, nonwoven fabrics, films (e.g., polymeric films, metallized polymeric films, continuous films, discontinuous films, and combinations thereof), foils (e.g., metal foils), sheets (e.g., metal sheets, polymeric sheets, continuous sheets, discontinuous sheets, and combinations thereof), and combinations thereof, preferably films.

[0105] The method for manufacturing a connection structure according to the present invention comprises the following steps: (a) providing a radiation curable composition according to the present invention; (b) applying the composition to a first component; (c) applying a second member to the composition on the first member to form a connection structure; (d) irradiating the connection structure with visible light having a wavelength of 400 nm or more, preferably 400 nm to 500 nm; and (e) optionally, heating the composition on the connecting structure. Includes.

[0106] In step (b), the radiation-curable adhesive composition of the present invention can be applied to the part using any suitable application method, preferably molding, including, for example, automated fine line dispensing, jet dispensing, slot die coating, roll coating, gravure coating, transfer coating, pattern coating, screen printing, spray coating, filament coating, extrusion, air knife, trailing blade, brushing, dipping, doctor blade, offset gravure coating, rotogravure coating, bonding, casting, molding, sealing, and combinations thereof. The radiation-curable adhesive composition can be applied as a continuous or discontinuous coating, in single or multiple layers, and combinations thereof.

[0107] The radiation exposure time in step (d) can be as short as 1 second and as long as 20 minutes, and preferably from 1 second to 10 minutes.

[0108] Preferably, the light emitting source is an LED light emitting lamp. Commercially available LED light emitting lamps have a maximum emission at 450 nm and an output of 300-500 mW / cm. 2 A product having a strength of 1000 mg / kg is available from UVATA under the trade name UPP10SIF-031.

[0109] Immediately after irradiation, final curing occurs at room temperature within a maximum of 7 days, preferably within 5 days, and particularly preferably within 3 days. The curing reaction can be accelerated by heating.

[0110] In step (e), heat can be introduced by means of, for example, a convection oven, a thermos pot, an IR radiator, a laser, or induction.

[0111] At a temperature of 60°C, the radiation-curable adhesive composition can be fully cured within 4 hours, preferably within 2 hours. At a temperature of 80°C, curing is usually complete within 2 hours, preferably within 1 hour. Temperature gradient cure profiles are also possible.

[0112] According to a fourth aspect of the present invention, there is provided herein an electronic device comprising the connecting structure of the present invention or manufactured using the adhesive composition of the present invention.

[0113] <Use> According to a fifth aspect of the present invention, there is provided herein the use of a radiation-curable adhesive composition according to the present invention or a connecting structure according to the present invention in the manufacture of an electronic device.

[0114] Suitable electronic devices include, but are not limited to, wearable electronic devices (e.g., watches and eyeglasses), handheld electronic devices (e.g., phones (e.g., used by mobile phones and smartphones), cameras, tablets, e-readers, monitors (e.g., monitors used in hospitals and by medical professionals, athletes, and individuals), watches, calculators, mice, touchpads, and joysticks), computers (e.g., desktop and laptop computers), computer monitors, televisions, media players, or other electronic components, preferably camera modules. [Example]

[0115] The following examples are intended to aid those skilled in the art in better understanding and practicing the present invention. The scope of the present invention is not limited by the examples, but rather is defined by the appended claims. Unless otherwise specified, all parts and percentages are by weight.

[0116] Raw materials: (A1) Celloxide 2021 P is a cycloaliphatic epoxy resin available from Daicel Corporation. (B1-1) R-Gen™ 261 has a (η 5 -2,4-cyclopentadien-1-yl)[(1,2,3,4,5,6-η)-(1-methylethyl)benzene]-iron(I)-hexafluorophosphate (solid), available from Chitec Technology. (B1-2)R-Gen (trademark) 262 is (η 5 -2,4-cyclopentadien-1-yl)[(1,2,3,4,5,6-η)-(1-methylethyl)benzene]-iron(I)-hexafluoroantimonate (solid), and is available from Chitec Technology. (B2) BLUESIL (trademark) PI 2074 is (tritylmethyl)iodonium tetrakis(pentafluorophenyl)borate (solid), and is available from Bluestar. (B2’) UVI6976 is a triarylsulfonium hexafluoroantimonate salt in 50 wt% propylene carbonate, and is available from Dow. (C1) Trigonox 141 is 2,5-bis(2-ethylhexanoylperoxy)-2,5-dimethylhexane, and is available from Akzo Nobel. (D1) SR 833 S is an acrylate monomer, and is available from Sartomer. (E1) Capa 3050 is a polyester polyol, and is available from Perstorp. (F1) PLV6 is a silica filler, and is available from Tatsumori. (F2) Sliquest A-187 is a silane accelerator, and is available from Momentive. (F3) TS720 is fumed silica, and is available from Cabot.

[0117] <Test method:> <State after irradiating the light with a wavelength of 450 nm under the PI film for 60 seconds> The compositions of each comparative example and example were discharged onto a polycarbonate substrate (1225Y) with a diameter of about 3 mm, and a polyimide (PI) film (Kapton HN PI film, thickness 50 μm, manufactured by Dupont) with a size of 110 × 35 mm was horizontally fixed at a distance of 5 mm above the adhesive dots.

[0118] Wavelength 450 nm, intensity 18 J / cm2 The PI film was cured by irradiating it with 300mW LED light (UVATA UPP10SIF-031) for 60 seconds, and then the sample was left at room temperature for 24 hours.

[0119] The compositions were optically evaluated to assess their condition. The condition is recorded in Table 1. A solid state indicates that the composition is completely cured beneath the PI film, which is a passing grade. A liquid state or a composition that is only surface-solidified is an unacceptable grade.

[0120] <Adhesion strength> Each of the compositions of the comparative examples and examples was dispensed onto a polycarbonate substrate (1225Y) with a diameter of approximately 3 mm, and a polyimide (PI) film (Kapton HN PI film, 50 μm thick, manufactured by DuPont) with dimensions of 110 × 35 mm was fixed horizontally on top of the adhesive dots at a distance of 5 mm.

[0121] Wavelength 450nm, intensity 18J / cm 2 The PI film was cured by irradiating it with 300mW LED light (UVATA UPP10SIF-031) for 60 seconds, and then the sample was left at room temperature for 24 hours.

[0122] To measure the breaking adhesive strength of the adhesive dots, the dot shear strength of the samples was measured on a DAGE 4000 shear tester at a test speed of 300 um / s. The shear force was tested and recorded in Kgf in Table 1. The adhesive composition was considered to pass if the shear force was 10 Kgf or greater, preferably 12 Kgf or greater.

[0123] <Examples 1 to 9 (Examples 1 to 9) and Comparative Examples 1 to 5 (Comparative Examples 1 to 5)> Each comparative example and example composition was prepared by the following steps: First, weighing out the ferrocenium salt (B1), if present, by weight mass as specified in Table 1 and dissolving it in 50% by weight of propylene carbonate based on the total weight of the ferrocenium salt solution before use; Second, weighing out the aromatic iodonium salt (B2), if present, by weight mass as specified in Table 1 and dissolving in 50% by weight of propylene carbonate based on the total weight of the aromatic iodonium salt solution prior to use; Third, mixing the two solutions until uniform; and Finally, the remaining ingredients in the weight masses specified in Table 1 are mixed with the mixture obtained in the third step in a Speedmixer DAC400 until a homogenous composition is formed.

[0124] The above process was carried out under yellow radiation with a wavelength of 595 nm. The properties were tested using the above methods, and the evaluation results are shown in Table 1.

[0125] [Table 1]

[0126] N / A means that the composition is not fully cured, and therefore the adhesive strength cannot be tested.

[0127] As can be seen from Table 1, Comparative Example 1, which does not contain peroxide, cannot be cured with radiation that penetrates PI film. Comparative Example 2, which does not contain aromatic iodonium salt (B2), and Comparative Example 3, which contains an aryl sulfonium salt instead of an aromatic iodonium salt, both cured after irradiation with light at a wavelength of 450 nm, but the adhesive strength of the compositions upon curing was unsatisfactory. Comparative Examples 4 and 5, in which the mass ratio of component (B2) to component (B1) or component (C) to component (B1) exceeded the claimed range, did not exhibit satisfactory adhesive strength upon curing. In contrast, the radiation-curable adhesive composition of the present invention exhibited excellent adhesive strength upon curing.

[0128] While several preferred embodiments have been described, many modifications and variations are possible in light of the above teachings, and it is therefore to be understood that the invention may be practiced otherwise than as specifically described without departing from the scope of the appended claims.

Claims

1. (A) At least one cationically polymerizable component (B) at least one photoinitiator system comprising (B1) at least one ferrocenium salt, and (B2) at least one aromatic iodonium salt; (C) at least one peroxide, and (D) optionally at least one free-radically polymerizable compound; wherein the mass ratio of component (B2) to component (B1) is 0.25 to less than 4, and the mass ratio of component (C) to component (B1) is 0.5 to 8.

2. Component (A) is selected from cyclic ether compounds, cyclic lactone compounds, cyclic acetal compounds, cyclic thioether compounds, spiro orthoester compounds, oxetane compounds and alicyclic epoxy resins, and more preferably 3-cyclohexenylmethyl-3-cyclohexylcarboxylate diepoxide, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 3,4-epoxy-6-methyl-cyclohexylmethyl-3,4-epoxy-6-methylcyclohexanecarboxylate, 2,2-bis(4-hydroxycyclohexyl) ...

2. The radiation-curable adhesive composition of claim 1, wherein the cycloaliphatic epoxy resin is selected from the group consisting of 3,4-epoxycyclohexylmethyl)propane diglycidyl ether, di(3,4-epoxycyclohexylmethyl)hexanedioate, di(3,4-epoxy-6-methylcyclohexylmethyl)hexanedioate, ethylene bis(3,4-epoxycyclohexanecarboxylate), ethanediol di(3,4-epoxycyclohexylmethyl)ether, 2-(3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy)cyclohexane-1,3-dioxane, and combinations thereof.

3. 3. The radiation-curable adhesive composition of claim 1, wherein component (B1) is selected from cumenylcyclopentadienyl iron(II) hexafluorophosphate, cumenylcyclopentadienyl iron(II) hexafluoroantimonate, naphthalenylcyclopentadienyl iron(II) hexafluorophosphate, benzylcyclopentadienyl iron(II) hexafluorophosphate, and cyclopentadienylcarbazole iron(II) hexafluorophosphate, and combinations thereof.

4. Component (B2) is [4-(isooctyloxy)phenyl]2-pyrazolyliodonium hexafluoroantimonate; [4-(2-ethylhexyloxy)phenyl]phenyliodonium hexafluoroantimonate; [4-(2-methylpentoxy)phenyl]phenyliodonium tetrafluoroborate; [4-(3-methylpentoxy)phenyl]phenyliodonium hexafluorophosphate; [4-(4-methylpentoxy)phenyl]phenyliodonium hexafluoroantimonate; [4-(2-propylpentoxy)phenyl]phenyliodonium hexafluoroantimonate; [4-(2,4,4-trimethylpentoxy)phenyl]phenyliodonium 4. The radiation-curable adhesive composition according to claim 1, wherein the hydroxyl group is selected from the group consisting of [4-(2-ethylhexyloxy)phenyl]-2-thienyliodonium hexafluorophosphate, [4-(2-ethylhexyloxy)phenyl]-2-furanyliodonium hexafluoroantimonate, [4-(2-ethylhexyloxy)phenyl]-2-furanyliodonium hexafluoroantimonate, tolylcumyliodonium tetrakispentafluorophenylborate, and combinations thereof.

5. 5. The radiation-curable adhesive composition according to claim 1, wherein the mass ratio of component (B2) to component (B1) is 0.25 to 3, more preferably 0.25 to 2, and even more preferably 0.5 to 1.

8.

6. 6. The radiation-curable adhesive composition according to claim 1, wherein component (C) is a peroxide containing no acyl group and / or a peroxide containing at least one acyl group selected from peracids, acyl peroxides containing no ester group, peroxyesters and peroxycarbonate type compounds, preferably peroxyesters.

7. 7. The radiation-curable adhesive composition according to claim 1, wherein the ratio of component (C) to component (B1) is 0.5 to 6, preferably 1 to 6, and more preferably 1 to 5.

8. The radiation-curable adhesive composition according to any one of claims 1 to 7, wherein component (D) is selected from acrylate and methacrylate monomers, oligomers, and / or polymers.

9. 9. The radiation-curable adhesive composition according to claim 1, wherein the composition further comprises a polyol component (E) selected from polyester polyols and / or polyether polyols, preferably polyester polyols.

10. 10. The radiation-curable adhesive composition according to claim 1, wherein the composition further comprises an additive (F) selected from a silane coupling agent, a filler, a thixotropic agent, a pigment, a surfactant, a preservative, a plasticizer, a lubricant, an antifoaming agent, and combinations thereof.

11. 11. The radiation-curable adhesive composition according to any one of claims 1 to 10, wherein the composition is curable by visible light transmitted through a polymer film, the visible light having a wavelength of 400 nm or more, preferably 400 nm to 500 nm.

12. A connection structure comprising a first member, a second member, and an adhesive sandwiched therebetween, wherein the first member and the second member are independently selected from glass, a polymer film, and a metal, and preferably at least one member is a polymer film, and the adhesive is formed by curing a radiation-curable adhesive composition according to any one of claims 1 to 11.

13. The following steps: (a) providing a radiation curable composition according to any one of claims 1 to 11; (b) applying the composition onto a first member; (c) applying a second member to the composition on the first member to form a connection structure; (d) irradiating the connection structure with visible light having a wavelength of 400 nm or more, preferably 400 nm to 500 nm; and (e) optionally, heating the composition on the connecting structure; The method for manufacturing the connection structure according to claim 12, comprising:

14. An electronic device comprising the connecting structure according to claim 12 or produced using the radiation-curable adhesive composition according to any one of claims 1 to 11.

15. Use of the radiation-curable adhesive composition according to any one of claims 1 to 11 or the connecting structure according to claim 12 in the manufacture of an electronic device, preferably a camera module.

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