TW202210598A - Electrochemically debondable adhesive composition - Google Patents

Abstract

The present invention is directed to a curable and electrochemically debondable adhesive composition comprising, based on the weight of the composition: from 40 to 99 wt.% of (a) at least one ethylenically unsaturated non-ionic monomer; from 0.9 to 50 wt.% of (b) at least one polymerizable ionic compound, wherein said polymerizable ionic compound comprises: (b1) at least one compound in accordance with general formula IV; and / or (b2) at least one compound in accordance with general formula V; and, from 0.1 to 10 wt.% of (c) at least one free radical initiator.

Description

Adhesive composition for electrochemical debonding

The present invention relates to a curable adhesive composition that can be debonded from the specific substrate to which it is applied. More particularly, the present invention relates to a curable and electrochemically debonded adhesive composition comprising a polymerizable electrolyte.

Adhesive bonding and polymeric coatings are commonly used in the assembly and surface treatment of articles. It is used in place of mechanical fasteners such as screws, bolts and rivets to provide bonding with reduced machining costs and greater adaptability in the manufacturing process. The adhesive bond distributes stress evenly, reduces the likelihood of fatigue, and seals the joint from corrosive species.

Although adhesive bonding offers many advantages over mechanical fasteners, practical applications, such as recycling of bonded primary materials, are often difficult when it is necessary to disassemble the adhesively bonded items. Removal of the adhesive via mechanical processes such as sandblasting or wire brushing is often excluded, in part because the adhesive is disposed between the substrates and therefore cannot be accessed or is difficult to grind without damaging the substrate surface. Disassembly via the application of chemicals and/or high temperature (such as disclosed in US Patent Nos. 4,171,240 (Wong) and 4,729,797 (Linde et al.)) may be effective, but may be time-consuming and complex to perform; Additionally, the required aggressive chemicals and/or harsh conditions can damage the substrate being separated, making it unsuitable for subsequent applications.

Noticing these problems, certain authors have sought to develop electrochemically debondable adhesive compositions in which an electrical current is passed through the cured composition to break the bond at the adhesive-substrate interface.

US 2007/0269659 (Gilbert) describes an adhesive composition that can be debonded at two interfaces, the composition: (i) comprising a polymer and an electrolyte; (ii) promoting the bonding of two surfaces; and (iii) The anodic and cathodic interfaces are formed in response to applying a voltage across the two surfaces, debonding from both the anodic and cathodic surfaces.

US 2008/0196828 (Gilbert) describes a hot melt adhesive composition comprising: a thermoplastic component; and an electrolyte, wherein the electrolyte provides the composition with sufficient ionic conductivity to be able to pass between the composition and a conductive surface A faradaic reaction occurs at the formed bond and debonds the composition from the surface.

WO2007/142600 (Stora Enso AB) describes an electrochemically weakenable adhesive composition that provides adhesive bonding to conductive surfaces and sufficient ionically conductive properties to allow the adhesive to adhere when a voltage is applied across the adhesive composition. The agent bonding can be weakened, wherein the composition includes an effective amount of at least one ionic compound to impart the plasma conductive properties, and wherein the ionic compound has a melting point of not more than 120°C.

EP 3363875 A (Nitto Denko Company) provides an electrically peelable adhesive composition which forms an adhesive layer with high adhesion and easily peelable after short-time application of a voltage. The electrically peelable adhesive composition of the present invention comprises a polymer and an ionic liquid of 0.5 to 30 wt.% based on the weight of the polymer, wherein the anion of the ionic liquid is bis(fluorosulfonyl)imide anion.

WO2013/135677 (Henkel AG & Co. KgaA) describes a hot melt adhesive comprising: 20 to 90 wt% of at least one polymer having a molecular weight (Mw) of 10,000 to 250,000 g/mol amide; 1 to 25 wt% of at least one organic or inorganic salt; and 0 to 60 wt% of other additives, wherein the adhesive has a softening point of 100°C to 220°C.

WO2016/135341 (Henkel Corporation) describes a reactive hot-melt adhesive composition that at least partially loses its adhesive strength upon application of a voltage and thus debonds substrates that have been bonded with the adhesive. More specifically, the reactive hot melt adhesive composition comprises: a) at least one isocyanate functional polyurethane polymer; and b) at least one organic or inorganic salt.

WO2017/133864 (Henkel Corporation) describes a method for reversibly bonding a first substrate and a second substrate, wherein at least the first substrate is a non-conductive substrate, the method comprising: a) coating the non-conductive (etc.) with a conductive ink; the surface of the conductive substrate; b) applying the electrically debonded hot melt adhesive composition to the conductive ink-coated surface of the first substrate and/or the second substrate; c) making the first substrate and the second substrate contacting such that the electrically debondable hot melt adhesive composition is interposed between the two substrates; d) causing an adhesive bond to form between the two substrates to provide a bonded substrate; and e) applying the A voltage is applied to the bonded substrates, thereby substantially weakening the adhesion at at least one interface between the electrically debondable hot melt adhesive composition and the surface of the substrate.

Where ionic liquids or electrolytes are included in the adhesive composition, compatibility of the electrolyte with the polymer matrix can be difficult to achieve. In the known art, electrolyte leakage and phase separation from the cured polymer matrix have been identified as disadvantages in the application of electrically debondable adhesives.

There is still a need in the art to provide an adhesive composition that can be easily applied to the surfaces of substrates to be bonded, and that, after curing, can provide effective bonding in composite structures containing the substrates, but which can be A potential is conveniently applied across the cured adhesive to effectively debond from the substrates. In addition, the cured adhesive should provide a stable polymer matrix in which leakage of the components is minimized and in which phase separation does not occur.

及/或 b2)至少一種根據通式V之化合物：

其中：R⁷ 係選自：C₁ -C₃₀ 烷基；C₂ -C₈ 烯基；C₁ -C₃₀ 雜烷基；C_{3 -} C₃₀ 環烷基；C₆ -C₁₈ 芳基；C₁ -C₉ 雜芳基；C_{7 -} C₁₈ 烷芳基；C_{2 -} C₅ 雜環烷基；或-R^a -C(=O)-R^b ，其中R^a 係C₁ -C₆ 伸烷基且R^b 係C₁ -C₆ 烷基； 各R⁸ 係獨立地選自H、C₁ -C₁₈ 烷基、C₁ -C₁₈ 雜烷基、C₃ -C₁₈ 環烷基、C₆ -C₁₈ 芳基、C₁ -C₉ 雜芳基、C_{7 -} C₁₈ 烷芳基或C₂ -C₅ 雜環烷基； R⁹ 係H或C₁ -C₄ 烷基； 各R¹⁰ 係獨立地選自：C₁ -C₃₀ 烷基；C₁ -C₃₀ 雜烷基；C_{3 -} C₃₀ 環烷基；C₆ -C₁₈ 芳基；C₁ -C₉ 雜芳基；C_{7 -} C₁₈ 烷芳基；C_{2 -} C₅ 雜環烷基；或-R^a -C(=O)-R^b ，其中R^a 係C₁ -C₆ 伸烷基且R^b 係C₁ -C₆ 烷基； A係非可聚合陰離子； T係烯系不飽和陰離子； d及m各自為具有至少1之值的整數； e及n具有使得該化合物呈電中性之數值；及，

係共價鍵、C₁ -C₂ 伸烷基、-CH₂ OC(=O)-、-CH₂ CH₂ OC(=O)-、對苯甲基或對甲苯基；及， 0.1至10 wt.%，較佳0.1至5 wt.%之c)至少一種自由基引發劑。According to a first aspect of the present invention, there is provided a curable and electrochemically debonded adhesive composition, based on the weight of the composition, comprising: 40 to 99 wt.%, preferably 45 to 90 wt.% % of a) at least one ethylenically unsaturated nonionic monomer; 0.9 to 50 wt.%, preferably 5 to 30 wt.% of b) at least one polymerizable ionic compound, wherein the polymerizable ionic compound comprises: b1) At least one compound according to general formula IV:

and/or b2) at least one compound according to general formula V:

Wherein: R ⁷ is selected from: C ₁ -C ₃₀ alkyl; C ₂ -C ₈ alkenyl; C ₁ -C ₃₀ heteroalkyl _; C ₃ -C ₃₀ cycloalkyl; C ₆ -C ₁₈ aryl; C ₁ -C ₉ heteroaryl _; C ₇ -C ₁₈ alkaryl _; C ₂ -C ₅ heterocycloalkyl; or -R ^a -C(=O)-R ^b , where R ^a is C ₁ -C ₆ alkylene and R ^b is C ₁ -C ₆ alkyl; each R ⁸ is independently selected from H, C ₁ -C ₁₈ alkyl, C ₁ -C ₁₈ heteroalkyl, C ₃ -C ₁₈ cycloalkane base, C ₆ -C ₁₈ aryl, C ₁ -C ₉ heteroaryl _, C ₇ -C ₁₈ alkaryl or C ₂ -C ₅ heterocycloalkyl; R ⁹ is H or C ₁ -C ₄ alkyl ; each R ¹⁰ is independently selected from: C ₁ -C ₃₀ alkyl; C ₁ -C ₃₀ heteroalkyl _; C ₃ -C ₃₀ cycloalkyl; C ₆ -C ₁₈ aryl; C ₁ -C ₉ heteroalkyl Aryl _; C ₇ -C ₁₈ alkaryl _; C ₂ -C ₅ heterocycloalkyl; or -R ^a -C(=O)-R ^b , wherein R ^a is C ₁ -C ₆ alkylene and R ^b is a _C1 - _C6 alkyl group; A is a non-polymerizable anion; T is an ethylenically unsaturated anion; d and m are each an integer having a value of at least 1; value; and,

is a covalent bond, C ₁ -C ₂ alkylene, -CH ₂ OC(=O)-, -CH ₂ CH ₂ OC(=O)-, p-benzyl or p-tolyl; and, 0.1 to 10 wt.%, preferably 0.1 to 5 wt.% of c) at least one free radical initiator.

The adhesive composition can be formulated as a one-component (1K), two-component (2K) or multi-component composition. A preference can be noted for part b), which consists of the compounds according to part b1) and/or part b2).

In one embodiment of the composition, part a) thereof comprises 40 to 95 wt.%, preferably 45 to 90 wt.% of a1) at least one (methyl) compound represented by formula I, based on the weight of the composition ) acrylate monomer: H ₂ C=CGCO ₂ R ¹ (I) wherein: G is hydrogen, halogen or C ₁ -C ₄ alkyl; and, R ¹ is selected from C ₁ -C ₃₀ alkyl, C ₂ -C ₃₀ heteroalkyl, C ₃ -C ₃₀ cycloalkyl, C ₂ -C ₈ heterocycloalkyl, C ₂ -C ₂₀ alkenyl and C ₂ -C ₁₂ alkynyl.

Part a) of the composition may be further characterized by comprising 0 to 30 wt.%, eg 0 to 15 wt.% of a2) at least one (meth)acrylate represented by formula II, based on the weight of the composition Monomer: H ₂ C=CQCO ₂ R ² (II) wherein: Q can be hydrogen, halogen or C ₁ -C ₄ alkyl; and, R ² can be selected from C ₆ -C ₁₈ aryl, C ₁ -C ₉ heteroaryl, C ₇ -C ₁₈ alkaryl and C ₇ -C ₁₈ aralkyl.

In another embodiment of the composition, which is not intended to be mutually exclusive with the embodiments given above, part a) thereof comprises 0 to 50 wt.%, preferably 5 to 25 wt.%, by weight of the composition wt.% of a3) at least one (meth)acrylate functionalized oligomer.

With regard to the electrolyte b) of the curable and electrochemically debonded composition, the ionic compounds according to formulae IV and V, as defined above and as detailed below, both contain functional groups reactive towards free-radical polymerization, preferably is a vinyl, allyl or propenyl functional group. The polymerizable electrolyte should thus polymerize with any of the aforementioned monomers a).

Regarding the compounds of formula IV (b1), the cations are based on imidazolium rings and become covalently bound to the adhesive matrix after completing the selected curing profile: the counter anion (A) is free to move in the polymer matrix. In contrast, with compounds of formula V(b2), the anions of the polymerizable electrolyte become covalently bonded to the adhesive matrix after curing and the cations based on the imidazolium ring are free to move in the matrix.

Preferred compounds b1) can exist alone or in combination, including but not limited to: 3-vinyl-1-methyl-1H-imidazolium iodide; 3-vinyl-1-methyl-1H-imidazolium chloride compound; 3-vinyl-1-methyl-1H-imidazolium bromide; 3-vinyl-1-methyl-1H-imidazolium methanesulfonate; 3-vinyl-1-methyl-1H- Imidazolium 1,1,1-Trifluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonamide; 3-Vinyl-1-ethyl-1H-imidazolium 1,1,1-tris Fluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonamide; 3-vinyl-1-methyl-1H-imidazolium hexafluorophosphate; 3-vinyl-1-methyl-1H -Imidazolium 4-methylbenzenesulfonate; 3-Vinyl-1-methyl-1H-imidazolium tetrafluoroborate; 3-Vinyl-1-ethyl-1H-imidazolium iodide; 3- Vinyl-1-ethyl-1H-imidazolium bromide; 3-vinyl-1-ethyl-1H-imidazolium 1,1,1-trifluoro-N-[(trifluoromethyl)sulfonyl ]methanesulfonamide; 3-vinyl-1-ethyl-1H-imidazolium hexafluorophosphate; 3-vinyl-1-ethyl-1H-imidazolium tetrafluoroborate; 3-vinyl-1 -(1-Methylethyl)-1H-imidazolium bromide; 3-(1,1-dimethylethyl)-1-vinyl-1H-imidazolium bromide; 3-vinyl-1- Propyl-1H-imidazolium bromide; 3-vinyl-1-(benzyl)-1H-imidazolium bromide; 1-vinyl-3-(4-methylphenyl)-1H-imidazolium Chloride; 3-Vinyl-1-(1-methylpropyl)-1H-imidazolium chloride; 1-Butyl-3-vinyl-1H-imidazolium bromide; 3-[(4-Ethylene phenyl)methyl]-1-methyl-1H-imidazolium iodide; 3-[(4-vinylphenyl)methyl]-1-methyl-1H-imidazolium chloride; 3-[ (4-Vinylphenyl)methyl]-1-methyl-1H-imidazolium 1,1,1-trifluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonamide; 3- [(4-Vinylphenyl)methyl]-1-methyl-1H-imidazolium hexafluorophosphate; 3-[(4-vinylphenyl)methyl]-1-methyl-1H-imidazole Onium tetrafluoroborate; 3-[(4-vinylphenyl)methyl]-1-ethyl-1H-imidazolium chloride; 1-[(4-vinylphenyl)methyl]-3- Ethyl-1H-imidazolium salt with 1,1,1-trifluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonamide; 1-(3-aminopropyl)-3-[ (4-Vinylphenyl)methyl]-1H-imidazolium chloride; 1-butyl-3-[(4-vinylphenyl)methyl]-1H-imidazolium chloride.

Preferred compounds b2) can exist alone or in combination, including but not limited to: 1-methyl-3-hexyl-1H-imidazolium 4-vinylbenzenesulfonate; 1-dodecyl-3-ethylene 1H-imidazolium 4-vinylbenzenesulfonate; 1-methyl-3-propyl-1H-imidazolium 4-vinylbenzenesulfonate; and 3-ethyl-1-methyl-1H - Imidazolium 4-(1-methylvinyl)benzenesulfonate.

In particular, good results are obtained when part b) of the composition comprises or consists of at least one compound selected from the group consisting of: 3-methyl-1-hexyl-1H-imidazolium 4-ethene 3-vinyl-1-ethyl-1H-imidazolium 1,1,1-trifluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonamide; and 3- Methyl-1-butyl-1H-imidazolium 1,1,1-trifluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonamide.

According to a second aspect of the present invention, a bonding structure is provided, the structure comprising: a first material layer having a conductive surface; and, a second material layer having a conductive surface, wherein a cured electrochemically debondable adhesive composition as defined above and in the scope of the appended claims is disposed between the first material layer and the second material layer.

According to a third aspect of the present invention, there is provided a method of debonding the bonding structure as defined above and in the scope of the appended application, the method comprising the steps of: i) applying a voltage across the two surfaces to form an anode interface and a cathode interface; and, ii) debonding the surfaces.

A preferred feature of step i) of this method is at least one of the following: a) an applied voltage of 1 to 100 V; and, b) The voltage is applied for 1 second to 180 minutes.

By applying an electrical potential across the adhesive layer between the composition and the conductive surface, the adhesive properties of the composition are destroyed. Without wishing to be bound by theory, it is believed that the Faradaic reaction that occurs at the interface between the adhesive composition and the conductive surface disrupts the interaction between the adhesive and the substrate, thereby weakening the bond therebetween. The interfacial failure can be the result of one or more processes, such as chemical degradation of the debondable material, gas evolution at the interface, and/or embrittlement of the material by changing the crosslink density of the adhesive composition.

Definitions As used herein, the singular forms " a (a/an) " and " the " include plural referents unless the context clearly dictates otherwise.

As used herein, the term " comprising /comprises/comprised of " is synonymous with " including /includes " or " containing /contains " and is inclusive or open-ended and does not exclude additional Unlisted members, elements or method steps.

As used herein, the term " consisting of " excludes any element, ingredient , member or method step not specified .

When amounts, concentrations, dimensions and other parameters are expressed in terms of ranges, preferred ranges, upper values, lower values, or preferred upper values and preferred lower values, it should be understood that it is also specifically disclosed by Any range obtained by combining any upper value or preferred value with any lower value or preferred value, regardless of whether the obtained range is explicitly mentioned in the context or not.

Furthermore, according to standard understanding, a weight range denoted " 0 to x " specifically includes 0 wt.%: the ingredients defined by this range may not be present in the composition or may be present in the composition in an amount of up to x wt.%.

The words " preferred, "" preferably, "" suitable ," and " especially " are frequently used herein to refer to embodiments of the invention that, under certain circumstances, may provide particular benefits. However, the recitation of one or more preferred/preferred, desired or particular embodiments does not imply that other embodiments are inapplicable and is not intended to exclude such other embodiments from the scope of the invention.

As used throughout this application, the word " may " is used in the permissible sense, that is, it means possible, and not in the mandatory sense.

As used herein, room temperature is 23°C ± 2°C. As used herein, " ambient conditions " means the temperature and pressure of the environment in which the composition is exposed or the environment in which the coating or substrate of the coating is exposed.

A " two-component ( 2K ) composition " in the context of the present invention is to be understood as one in which the first component (1) and the second component (2) have to be stored in separate containers due to their (high) reactivity combination. The two components are mixed only shortly before coating and then react, usually without further activation, to form bonds and thus a polymeric network. Here, higher temperatures may be applied in order to promote the cross-linking reaction.

As used herein, the term " electrochemically debondable " means that after curing of the adhesive, the bond strength can be weakened by at least 50% after applying a potential of 50 V for 60 minutes. A cured adhesive is applied between two substrates, and the substrates are bonded by the adhesive so that current flows through the adhesive bonding layer. Bond strength is determined by tensile lap shear (TLS) testing at room temperature and based on ASTM D3163-01 (Determination of Shear Strength of Adhesive Bonded Rigid Plastic Lap Shear Joints by Tensile Loading Method Standard Test Method for Determining Strength of Adhesively Bonded Rigid Plastic Lap - Shear Joints in Shear by Tension Loading ) for measurement. The bond overlap area is 2.5 cm x 1.0 cm (1" x 0.4") and the bond thickness is 0.1 cm (40 mil).

The term " electrolyte " is used herein according to its standard meaning in the art as a substance containing free ions that can conduct electricity by displacement of charged carrier species. The term is intended to encompass molten electrolytes, liquid electrolytes, semi-solid electrolytes and solid electrolytes in which at least one of the cationic or anionic components of the electrolyte structure is substantially free to displace, thus acting as charge carriers.

The curable adhesive composition of the present invention and the cured adhesive obtained therefrom have an " electrolyte function " in that the adhesive material allows ionic conduction, whether anionic, cationic, or both.

Electrolyte function is understood to result from the ability of the composition and cured adhesive to solubilize ions of at least one polarity.

The term " Faraday reaction " means an electrochemical reaction in which a species is oxidized or reduced.

As used herein, the term " monomer " refers to a substance that can undergo a polymerization reaction to provide structural units to the chemical structure of a polymer. As used herein, the term " monofunctional " means having one polymerizable moiety. As used herein, the term " multifunctional " means having more than one polymerizable moiety.

As used herein, the term " ethylenically unsaturated monomer " refers to any monomer containing a terminal double bond capable of polymerizing under normal conditions for free radical addition polymerization.

As used herein, the term " equivalent weight ( eq . )" relates to the relative number of reactive groups present in a reaction, as is common in chemical notation.

As used herein, " ( meth ) propenyl " refers to the shorthand term for " propenyl " and/or " methpropenyl ". Thus, the term " ( meth ) acrylate " refers collectively to acrylates and methacrylates.

As used herein, a " C ₁ -C _n alkyl " group refers to a monovalent group containing 1 to n carbon atoms, which is a group of alkanes, and includes straight and branched chain organic groups. Thus, a " C ₁ -C ₃₀ alkyl " group refers to a monovalent group containing 1 to 30 carbon atoms, which is an alkane group, and includes straight and branched chain organic groups. Examples of alkyl groups include, but are not limited to: methyl; ethyl; propyl; isopropyl; n-butyl; isobutyl; tertiary butyl; tertiary butyl; n-pentyl; n-hexyl; n-heptyl ; and 2-ethylhexyl. In the present invention, such alkyl groups may be unsubstituted or may be substituted with one or more substituents selected from halogen, hydroxy, nitrile (-CN), amido and amine ( _-NH2 ). Where applicable, the preferred substituents for a given group will be indicated in this specification. In general, however, it should be noted that alkyl groups containing 1 to 18 carbon atoms (C ₁ -C ₁₈ alkyl groups) are preferred, such as alkyl groups containing 1 to 12 carbon atoms (C ₁ -C ₁₂ alkyl groups) ) or an alkyl group of 1 to 6 carbon atoms (C ₁ -C ₆ alkyl).

As used herein, the term " C ₁ -C ₁₈ hydroxyalkyl " refers to a HO-(alkyl) group having 1 to 18 carbon atoms, wherein the point of attachment of the substituent is through an oxygen atom and the alkyl group is as above defined.

" Alkoxy " refers to a monovalent group represented by -OA, where A is an alkyl group: non-limiting examples of which are methoxy, ethoxy, and isopropoxy.

As used herein, the term " _Ci - _C6 alkylene " is defined as a saturated divalent hydrocarbon group having a straight chain, branched chain or cyclic moiety or a combination thereof and having from 1 to 6 carbon atoms.

The term " C ₃ -C ₃₀ cycloalkyl " is understood to mean an optionally substituted saturated monocyclic, bicyclic or tricyclic hydrocarbon radical having 3 to 30 carbon atoms. In general, it should be noted that cycloalkyl groups containing 3 to 18 carbon atoms (C ₃ -C ₁₈ cycloalkyl groups) are preferred. Examples of cycloalkyl groups include: cyclopropyl; cyclobutyl; cyclopentyl; cyclohexyl; cycloheptyl; cyclooctyl; In the present invention, such cycloalkyl groups may be unsubstituted or may be substituted with one or more substituents selected from halogen, _C1 - _C6 alkyl and _C1 - _C6 alkoxy.

As used herein, " _{C6 -} Ci8 aryl " used alone or as part of a larger moiety (as in " aralkyl ") refers to optionally substituted monocyclic, bicyclic and tricyclic ring systems wherein A monocyclic ring system is aromatic, or at least one ring of a bicyclic or tricyclic ring system is aromatic. Bicyclic and tricyclic systems include benzo-fused 2-3 membered carbocyclic rings. In the present invention, such aryl groups may be unsubstituted or may be substituted with one or more substituents selected from halogen, _C1 - _C6 alkyl and _C1 - _C6 alkoxy. Exemplary aryl groups include: phenyl; (C ₁ -C ₄ )alkylphenyl, such as tolyl and ethylphenyl; indenyl; naphthyl, tetrahydronaphthyl, tetrahydroindenyl; tetrahydroanthracenyl ; and anthracenyl. And it can be noted that phenyl is preferred.

As used herein, " C2 _{- C20} alkenyl " refers to a hydrocarbon group having 2 to 20 carbon atoms and at least one unit of ethylenic unsaturation. Alkenyl groups can be straight chain, branched chain or cyclic and optionally substituted. As understood by those of ordinary skill in the art, the term " alkenyl " also encompasses groups having " cis " and " trans " configurations, or alternatively, " E " and " Z " configurations. In general, however, it should be noted that unsubstituted alkenyl groups containing 2 to 10 (C _2-10 ) or 2 to 8 (C _2-8 ) carbon atoms are preferred. Examples _of such C2 _- C12 alkenyl groups include, but are not limited to: -CH═CH2; _-CH═CHCH3 ; _-CH2CH═CH2 ; _-C ( _═CH2 )( _{CH3 )} ; -CH ═CHCH2CH3;-CH2CH═CHCH3 _{; -CH2CH2CH═CH2 ;} -CH═C( _{CH3 ) 2 ; -CH2C} ( _{═CH2 )} ( _{CH3 )} ;-C ( _═CH2 ) _CH2CH3 ; _-C ( _{CH3 ) ═CHCH3} ; _-C ( _{CH3 ) CH═CH2} ; _{-CH═CHCH2CH2CH3 ; -CH2CH═CHCH2CH3 -CH2CH2CH═CHCH3 ; -CH2CH2CH2CH═CH2 ; -C} ( _{═CH2 ) CH2CH2CH3 ; -C} ( _{CH3 ) ═CHCH2CH3 ; -} CH(CH ₃ )CH═CHCH _; -CH(CH ₃ )CH ₂ CH═CH ₂ ; -CH ₂ CH═C(CH ₃ ) ₂ ; 1-cyclopent-1-enyl; 1-cyclopent-2 - alkenyl; 1-cyclopent-3-enyl; 1-cyclohex-1-enyl; 1-cyclohex-2-enyl; and 1-cyclohexyl-3-enyl.

As used herein, " alkaryl " refers to an aryl group substituted with an alkyl group, and " substituted alkaryl " refers to an alkaryl group further bearing one or more substituents as described above. Also, as used herein, " aralkyl " means an alkyl group substituted with an aryl group as defined above.

As used herein, the term " hetero " refers to a group or moiety containing one or more heteroatoms selected from N, O, Si, P, and S. Thus, for example, " heterocycle " refers to a cyclic group having N, O, Si, P or S as part of the ring structure. " Heteroalkyl ,"" heterocycloalkyl ," and " heteroaryl " moieties are alkyl, cycloalkyl, and Aryl.

For completeness, the term " _C2 - _C30 heteroalkyl " refers to an " alkyl " in which at least one carbon atom is replaced by a heteroatom, the group having a total of 2 to 30 carbon atoms. A specific example of such a heteroalkyl group is " C ₂ -C ₁₈ alkoxyalkyl " , which herein refers to an alkyl group having an alkoxy substituent as defined above and wherein the moiety ( alkyl - O -Alkyl ) contains a total of 1 to 18 carbon atoms : such groups include methoxymethyl ( _-CH2OCH3 ), _{2 -} methoxyethyl ( _-CH2CH2OCH3 ) and _{2- Ethoxyethyl ( -CH2CH2OCH2CH3 )} . Another example of a heteroalkyl group is " _C2 - _{C30aminoalkyl} ", which herein refers to an alkyl group selected from -NH(R'), -N(R')(R'') or N ⁺ (R')(R'')(R''') alkyl substituted with at least one group: wherein R', R'' and R''' are C ₁ -C ₆ alkyl, but limited Provided that the group contains a total of 2 to 30 carbon atoms: such groups include 2-(dimethylamino)ethyl, 2-(diethylamino)ethyl and 2-(trimethylamino)ethyl .

The term "Ci-C9heteroaryl" denotes an aryl group having ₁ to ₉ carbon atoms and 1 to 4 heteroatoms, which group may be attached via a heteroatom (if applicable) or a carbon atom. The heteroaryl ring can be fused or otherwise attached to one or more heteroaryl rings, aromatic or non-aromatic hydrocarbon rings, or heterocycloalkyl rings. Examples of heteroaryl groups include, but are not limited to: pyridine; furan; thiophene; 5,6,7,8-tetrahydroisoquinoline; pyrimidine; thienyl; benzothienyl; pyridyl; quinolinyl; ; pyrimidinyl; imidazolyl; benzimidazolyl; furyl; benzofuranyl; thiazolyl; benzothiazolyl; isoxazolyl; oxadiazolyl; isothiazolyl; benzisothiazolyl; triazole tetrazolyl; pyrrolyl; indolyl; pyrazolyl; and benzopyrazolyl.

The term " _C2 - C8heterocycloalkyl " denotes a saturated cyclic hydrocarbon group having 2 to ₈ carbon atoms and 1 to 4 heteroatoms, which group may be attached via a heteroatom (if applicable) or a carbon atom. The heterocycloalkyl ring is optionally fused or otherwise attached to other heterocycloalkyl rings and/or non-aromatic hydrocarbon rings. Preferred heterocycloalkyl groups have 3 to 7 ring atoms. Examples of heterocycloalkyl include, but are not limited to: piperidine; morpholine; piperidine; tetrahydrofuran; pyrrolidine; pyrazole; piperidinyl; piperidine; morpholinyl; and pyrrolidinyl.

As used herein, the term " aliphatic " includes saturated and unsaturated, non-aromatic, straight chain, branched chain, acyclic or cyclic hydrocarbons, optionally substituted with one or more functional groups, with the limitation that Substitution results in the formation of stable moieties. As will be understood by those skilled in the art, " aliphatic " is intended to encompass alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, and cycloalkynyl moieties.

As used herein, " aromatic " refers to a large class of unsaturated cyclic hydrocarbons containing one or more rings, such cyclic hydrocarbons may contain carbon (C), nitrogen (N), oxygen (O), sulfur (S), Boron (B) or any combination thereof. Also includes at least some carbon. Aromatic includes both aryl and heteroaryl rings. The aryl or heteroaryl ring may be further substituted with additional aliphatic, aromatic or other groups, provided that the substitution results in the formation of a stabilizing moiety.

As used herein, the term " radical initiator " refers to any chemical that, upon exposure to sufficient energy (in the form of radiation, heat, or the like), decomposes into two uncharged moieties, each having at least one unpaired electron species. For completeness, the term " radical initiator " encompasses thermal free radical initiators and free radical photoinitiators, which can be activated upon exposure to an energy-loaded activation beam, such as electromagnetic radiation: in this context the preferred use of thermal Free radical initiator.

The molecular weights of the macromolecular, oligomeric and polymeric components of the curable composition described in this specification can be quantified by gel permeation chromatography (GPC) using polystyrene calibration standards, such as according to ASTM 3536 Measurement.

Unless otherwise specified, the viscosity of the coating compositions described herein is measured using a Brookfield Viscometer at standard conditions of 20°C and 50% relative humidity (RH). The calibration method, shaft type and rotational speed of the Brookfield viscometer are selected according to the manufacturer's instructions to suit the composition to be measured.

a) Non-ionic matrix monomers The compositions of the present invention comprise at least one ethylenically unsaturated nonionic monomer, the (co)polymerization of which produces a matrix of debondable adhesives. The monomer a) can in principle be any ethylenically unsaturated nonionic monomer. However, the present invention is particularly applicable to compositions wherein (meth)acrylic monomer constitutes at least 50 mol%, preferably at least 75 mol%, based on the total molar amount of ethylenically unsaturated nonionic monomers present .

a1) Aliphatic and cycloaliphatic (meth)acrylate monomers In an important embodiment of the present invention, the composition of the present invention contains 40 to 95 wt.%, preferably 45 to 95 wt.%, based on the weight of the composition. 90 wt.% of a1) at least one (meth)acrylate monomer represented by formula I: H ₂ C=CGCO ₂ R ¹ (I) wherein: G is hydrogen, halogen or C ₁ -C ₄ alkyl; And, R ¹ is selected from: C ₁ -C ₃₀ alkyl; C ₂ -C ₃₀ heteroalkyl; C ₃ -C ₃₀ cycloalkyl; C ₂ -C ₈ heterocycloalkyl; C ₂ -C ₂₀ alkene and C ₂ -C ₁₂ alkynyl.

For example, R ¹ can be selected from C ₁ -C ₁₈ alkyl, C ₂ -C ₁₈ heteroalkyl, C ₃ -C ₁₈ cycloalkyl, C ₂ -C ₈ heterocycloalkyl, C ₂ -C ₈ Alkenyl and C ₂ -C ₈ alkynyl.

The monomer a1) is advantageously characterized in that R ¹ is selected from the group consisting of C ₁ -C ₁₈ alkyl and C ₃ -C ₁₈ cycloalkyl. This statement of preference is expressly intended to include embodiments wherein R ¹ is C ₁ -C ₆ hydroxyalkyl.

Examples of (meth)acrylate monomers a1) according to formula (I) include, but are not limited to: methyl (meth)acrylate; ethyl (meth)acrylate; butyl (meth)acrylate; ) Hexyl acrylate; 2-ethylhexyl (meth)acrylate; dodecyl (meth)acrylate; lauryl (meth)acrylate; cyclohexyl (meth)acrylate; 𦯉ester; 2-hydroxyethyl (meth)acrylate (HEMA); 2-hydroxypropyl (meth)acrylate; ethylene glycol monomethyl ether (meth)acrylate; ethylene glycol monoethyl ether (methyl) Acrylates; Ethylene Glycol Monododecyl Ether (Meth)acrylate; Diethylene Glycol Monomethyl Ether (Meth)acrylate; Trifluoroethyl (Meth)acrylate; Fluoctyl.

a2) Aromatic (meth)acrylate monomers Based on the weight of the composition, the compositions of the present invention may further comprise 0 to 30 wt.%, for example 0.1 to 30 wt.%, 0.1 to 25 wt.% or 0.1 to 15 wt.% of a2) at least one (meth)acrylate monomer of formula II: H ₂ C=CQCO ₂ R ² (II) where: Q can be hydrogen, halogen or C ₁ -C ₄ alkyl and, R ² may be selected from C ₆ -C ₁₈ aryl, C ₁ -C ₉ heteroaryl, C ₇ -C ₁₈ alkaryl and C ₇ -C ₁₈ aralkyl.

Exemplary (meth)acrylate monomers a2) according to formula (II) that can be used alone or in combination include, but are not limited to: benzyl (meth)acrylate; phenoxyethyl (meth)acrylate; Phenoxydiethylene glycol (meth)acrylate; phenoxypropyl (meth)acrylate; and phenoxydipropylene glycol (meth)acrylate.

a3) (Meth)acrylate functional oligomers In an important embodiment of the present invention which is not intended to be mutually exclusive with the inclusion of aliphatic and cycloaliphatic monomers (a1) and aromatic monomers (a2), the compositions of the present invention should comprise 0 by weight of the composition to 50 wt.%, preferably 5 to 25 wt.% of a3) at least one (meth)acrylate functional oligomer. The oligomers may have one or more acrylate and/or methacrylate groups attached to the oligomeric backbone, the (meth)acrylate functional groups may be in terminal positions on the oligomer and /or may be distributed along the oligomeric backbone.

Preferably, the at least one (meth)acrylate functional oligomer: i) has two or more (meth)acrylate functional groups per molecule; and/or ii) has 300 to 1000 channels The weight average molecular weight (Mw) in ton.

Examples of such oligomers that may be used alone or in combination include, but are not limited to: (meth)acrylate functional urethane oligomers such as (meth)acrylate functional polyester urethane Ester and (meth)acrylate functionalized polyether urethanes; (meth)acrylate functionalized polyepoxy resins; (meth)acrylate functionalized polybutadienes; (meth)acrylic polyamides Alcohol (meth)acrylates; polyester (meth)acrylate oligomers; polyamide (meth)acrylate oligomers; and polyether (meth)acrylate oligomers. Such (meth)acrylate functionalized oligomers and methods for their preparation are disclosed inter alia in: US Patent No. 4,574,138; US Patent No. 4,439,600; US Patent No. 4,380,613; US Patent No. 4,309,526; US Patent No. 4,295,909 US Patent No. 4,018,851; US Patent No. 3,676,398; US Patent No. 3,770,602; US Patent No. 4,072,529; US Patent No. 4,511,732; Patent No. 4,206,025; US Patent No. 5,002,976. Among the aforementioned polyether (meth)acrylate oligomers, specific examples include, but are not limited to: PEG 200 DMA (n≈4); PEG 400 DMA (n≈9); PEG 600 DMA (n≈14); and PEG 800 DMA (n≈19) where the designated number (eg 400) represents the weight average molecular weight of the diol portion of the molecule.

The present invention does not exclude the presence of other ethylenically unsaturated nonionic monomers that do not meet the definitions of a1), a2) and a3). However, the addition of such other monomers should be limited by the fact that the total amount of ethylenically unsaturated nonionic monomers should not exceed 95 wt.%, based on the total weight of the composition. The total amount of ethylenically unsaturated nonionic monomers should preferably not exceed 90 wt.% based on the total weight of the composition.

Without intending to limit the invention, such other ethylenically unsaturated nonionic monomers may include: polysiloxane (meth)acrylate monomers, such as taught and claimed in US Pat. No. 5,605,999 (Chu) of them; α,β-ethylenically unsaturated monocarboxylic acids containing 3 to 5 carbon atoms, such as acrylic acid, methacrylic acid, crotonic acid; C ₁ -C ₁₈ alkyl crotonates; containing 4 to Alpha, beta-ethylenically unsaturated dicarboxylic acids of 6 carbon atoms and their anhydrides, monoesters and diesters; vinyl esters such as vinyl acetate, vinyl propionate and VEOVA available from Shell Chemical Company ^TM series monomers; vinyl halides and vinylidene halides; vinyl ethers, such as vinyl ethyl ether; vinyl ketones, including alkyl vinyl ketones, cycloalkyl vinyl ketones, aryl vinyl ketones, aralkanes vinyl ketones and arylcycloalkyl vinyl ketones; aromatic or heterocycloaliphatic vinyl compounds; poly(meth)acrylates of alkane polyols such as ethylene glycol di(meth)acrylate, propylene glycol Di(meth)acrylate, butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, hexanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate (meth)acrylates, glycerol tri(meth)acrylates and neotaerythritol tetra(meth)acrylates; poly(meth)acrylates of oxyalkane polyols such as diethylene glycol di(meth)acrylate ) acrylate, dipropylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, dibutylene glycol di(meth)acrylate, Di(1,5-pentanediol) dimethacrylate; polyethylene glycol di(meth)acrylate; and bisphenol A di(meth)acrylate, such as ethoxylated bisphenol A (meth)acrylate base) acrylate ("EBIPMA").

Representative examples of other ethylenically unsaturated polymerizable nonionic monomers include, but are not limited to: ethylene glycol dimethacrylate (EGDMA); fumaric anhydride, maleic anhydride, and itaconic anhydride; with C Mono- and diesters of ₁ - _C4 alcohols such as methanol, ethanol, propanol, isopropanol, butanol, isobutanol and tertiary butanol. Representative examples of vinyl monomers include, but are not limited to, compounds such as vinyl acetate; vinyl propionate; vinyl ethers, such as vinyl ethyl ether; and vinyl ethyl ketone. Representative examples of aromatic or heterocycloaliphatic vinyl compounds include, but are not limited to, compounds such as: styrene, alpha-methylstyrene, vinyltoluene, tertiary butylstyrene, 2-vinylpyrrolidine ketones, 5-ethylidene-2-nor alkene and 1-vinylcyclohexene, 3-vinylcyclohexene and 4-vinylcyclohexene.

及/或 b2)至少一種根據通式V之化合物：

其中：R⁷ 係選自：C₁ -C₃₀ 烷基；C₂ -C₈ 烯基；C₁ -C₃₀ 雜烷基；C_{3 -} C₃₀ 環烷基；C₆ -C₁₈ 芳基；C₁ -C₉ 雜芳基；C_{7 -} C₁₈ 烷芳基；C_{2 -} C₅ 雜環烷基；或-R^a -C(=O)-R^b ，其中R^a 係C₁ -C₆ 伸烷基且R^b 係C₁ -C₆ 烷基； 各R⁸ 係獨立地選自H、C₁ -C₁₈ 烷基、C₁ -C₁₈ 雜烷基、C₃ -C₁₈ 環烷基、C₆ -C₁₈ 芳基、C₁ -C₉ 雜芳基、C_{7 -} C₁₈ 烷芳基或C₂ -C₅ 雜環烷基； R⁹ 係H或C₁ -C₄ 烷基； 各R¹⁰ 係獨立地選自：C₁ -C₃₀ 烷基；C₁ -C₃₀ 雜烷基；C_{3 -} C₃₀ 環烷基；C₆ -C₁₈ 芳基；C₁ -C₉ 雜芳基；C_{7 -} C₁₈ 烷芳基；C_{2 -} C₅ 雜環烷基；或-R^a -C(=O)-R^b ，其中R^a 係C₁ -C₆ 伸烷基且R^b 係C₁ -C₆ 烷基； A係非可聚合陰離子； T係烯系不飽和陰離子； d及m各自為具有至少1之值的整數； e及n具有使得該化合物呈電中性之數值；及，

係共價鍵、C₁ -C₂ 伸烷基、-CH₂ OC(=O)-、-CH₂ CH₂ OC(=O)-、對苯甲基或對甲苯基。b) Electrolyte The composition of the invention comprises 0.9 to 50 wt.%, eg 5 to 50 wt.% or 10 to 45 wt.% of b) at least one polymerizable ionic compound, wherein the polymerizable ionic compound comprises: b1) at least A compound according to general formula IV:

and/or b2) at least one compound according to general formula V:

Wherein: R ⁷ is selected from: C ₁ -C ₃₀ alkyl; C ₂ -C ₈ alkenyl; C ₁ -C ₃₀ heteroalkyl _; C ₃ -C ₃₀ cycloalkyl; C ₆ -C ₁₈ aryl; C ₁ -C ₉ heteroaryl _; C ₇ -C ₁₈ alkaryl _; C ₂ -C ₅ heterocycloalkyl; or -R ^a -C(=O)-R ^b , where R ^a is C ₁ -C ₆ alkylene and R ^b is C ₁ -C ₆ alkyl; each R ⁸ is independently selected from H, C ₁ -C ₁₈ alkyl, C ₁ -C ₁₈ heteroalkyl, C ₃ -C ₁₈ cycloalkane base, C ₆ -C ₁₈ aryl, C ₁ -C ₉ heteroaryl _, C ₇ -C ₁₈ alkaryl or C ₂ -C ₅ heterocycloalkyl; R ⁹ is H or C ₁ -C ₄ alkyl ; each R ¹⁰ is independently selected from: C ₁ -C ₃₀ alkyl; C ₁ -C ₃₀ heteroalkyl _; C ₃ -C ₃₀ cycloalkyl; C ₆ -C ₁₈ aryl; C ₁ -C ₉ heteroalkyl Aryl _; C ₇ -C ₁₈ alkaryl _; C ₂ -C ₅ heterocycloalkyl; or -R ^a -C(=O)-R ^b , wherein R ^a is C ₁ -C ₆ alkylene and R ^b is a _C1 - _C6 alkyl group; A is a non-polymerizable anion; T is an ethylenically unsaturated anion; d and m are each an integer having a value of at least 1; value; and,

It is a covalent bond, C ₁ -C ₂ alkylene, -CH ₂ OC(=O)-, -CH ₂ CH ₂ OC(=O)-, p-benzyl or p-tolyl.

In the above formula, R ⁷ is preferably selected from: C ₁ -C ₁₂ alkyl; C ₂ -C ₆ alkenyl; C ₁ -C ₁₂ heteroalkyl; C ₃ -C ₁₈ cycloalkyl; C _{6 -} C ₁₈ aryl; C ₁ -C ₉ heteroaryl _; C ₇ -C ₁₈ alkaryl _; C ₂ -C ₅ heterocycloalkyl; or -R ^a -C(=O)-R ^b , where R ^a is C ₁ -C ₆ alkylene and R ^b is C ₁ -C ₆ alkyl. More specifically, R ⁷ is selected from: C ₁ -C ₈ alkyl; C ₂ -C ₄ alkenyl; C ₁ -C ₈ heteroalkyl _; C ₃ -C ₁₂ cycloalkyl; C ₆ -C ₁₈ Aryl; C ₁ -C ₉ heteroaryl _; C ₇ -C ₁₈ alkaryl _; C ₂ -C ₅ heterocycloalkyl; or -R ^a -C(=O)-R ^b , where R ^a is C ₁ -C ₄ alkylene and R ^b is C ₁ -C ₄ alkyl. Since ^R7 can be an alkenyl group, it should be noted that the imidazolium moiety may have more than one ethylenically unsaturated group: in this regard, exemplary moieties include: 1,3- divinyl1H -imidazolium; and 3 - vinyl-1-(2-propen-1-yl)-1 H -imidazolium.

Each R ⁸ is preferably independently selected from H or C ₁ -C ₆ alkyl, and more specifically independently selected from H or C ₁ -C ₂ alkyl. Mention may be made that preferably at least one R ⁸ is H. R ⁹ is preferably H or C ₁ -C ₂ alkyl, and more specifically, H or methyl.

Preferably each R ¹⁰ is independently selected from: C ₁ -C ₁₂ alkyl; C ₁ -C ₁₂ heteroalkyl _; C ₃ -C ₁₈ cycloalkyl; C ₆ -C ₁₈ aryl; C ₁ -C ₉ heteroalkyl Aryl _; C ₇ -C ₁₈ alkaryl _; C ₂ -C ₅ heterocycloalkyl; or -R ^a -C(=O)-R ^b , wherein R ^a is C ₁ -C ₆ alkylene and R ^b is C ₁ -C ₆ alkyl. More specifically, R ¹⁰ is selected from: C ₁ -C ₈ alkyl; C ₁ -C ₈ heteroalkyl _; C ₃ -C ₁₂ cycloalkyl; C ₆ -C ₁₈ aryl; C ₁ -C ₉ Heteroaryl _; C ₇ -C ₁₈ alkaryl _; C ₂ -C ₅ heterocycloalkyl; or -R ^a -C(=O)-R ^b , wherein R ^a is C ₁ -C ₄ alkylene and R ^b is C ₁ -C ₄ alkyl.

With respect to compounds of formula IV, the anion A is generally selected from the group consisting of: fluoride; chloride; bromide; iodide; perchlorate; nitrate; nitrite; phosphate; sulfate; sulfite; Carbonate; bicarbonate; hydrogen phosphate; hydrogen sulfate; hydrogen sulfite; dihydrogen phosphate; trifluorophosphate, hexafluorophosphate; methyl sulfate; acid; ethylsulfonate; 4-methylbenzenesulfonate; diethylphosphate; formate; acetate; propionate; tartrate; octanoate; bis(2,4,4-trimethylpentyl) phosphinate; bis(malonato)borate; bis(oxalato)borate; bis(pentafluoroethyl)phosphinate; tetracyanoborate; tetrafluoroborate; bis(phthalate) formate)borate; bis(salicylate)borate; bis(trifluoromethanesulfonic acid)imide; bis(trifluoromethanesulfonyl)methane; bis(trifluoromethyl)imide Acetate; 4(bisulfate)borate; 4(methylsulfonate)borate; trifluoromethanesulfonate; sine(heptafluoropropyl)trifluorophosphate; Fluorophosphate; Gins(pentafluoroethyl)trifluorophosphate; Gins(pentafluoroethylsulfonyl)trifluorophosphate; Trichlorozincate; Trifluoroacetate; Bromoaluminate; Chloroaluminate; Di Cuprate; thiocyanate; tosylate; and dicyanamide.

The anion A is preferably selected from the group consisting of: fluoride; chloride; bromide; iodide; perchlorate; nitrate; formate; acetate; octanoate; tetrafluoroborate; trifluorophosphate; Hexafluorophosphate; Methosulfate; Ethosulfate; Methylcarbonate; Methanesulfonate; 4-Methylbenzenesulfonate; Trifluoromethanesulfonate; Bis(trifluoromethanesulfonic acid)imide , trifluorophosphate and trifluoroacetate; and ginseng (perfluoroethyl) trifluorophosphate. More particularly, the anion A is selected from the group consisting of: fluoride; chloride; bromide; iodide; tetrafluoroborate; hexafluorophosphate; methylsulfate; ethylsulfonate; benzenesulfonate; and bis(trifluoromethanesulfonic acid)imide.

The anion T can be selected from: ethylenically unsaturated carboxylate anion (R-COO-); ethylenically unsaturated sulfonate anion (R-SO ₃ ^- ); ethylenically unsaturated phosphonate anion (R-PO ₃ ^{2 - )} ); ethylenically unsaturated phosphinate anion (RP(H)O ₂ ^- ); and ethylenically unsaturated phosphate anion (RO-PO ₃ ^{2 -} ), wherein R is an organic group containing ethylenic unsaturation, The organic groups polymerize under normal conditions and are preferably derived from (meth)acrylic acid, vinyl acid or allyl acid.

Representative anions T include: (meth)acrylate; itaconate; maleate; crotonate; isocrotonate; vinylbenzoate; 2-acrylamido-2-methyl propanesulfonate; sulfoethyl (meth)acrylate; sulfopropyl (meth)acrylate; sulfomethylated acrylamide; allylsulfonate; vinylsulfonate; 4-vinylbenzenesulfonate acid (4-styrenesulfonate); 4-isopropenylbenzenesulfonate (4-methylstyrenesulfonate); allylphosphonate; and monoacryloyloxyethylphosphate.

Exemplary compounds b1) according to formula IV include, but are not limited to: 3-vinyl-1-methyl-1H-imidazolium iodide; 3-vinyl-1-methyl-1H-imidazolium chloride; 3-vinyl-1-methyl-1H-imidazolium chloride; Vinyl-1-methyl-1H-imidazolium bromide; 3-vinyl-1-methyl-1H-imidazolium methanesulfonate; 3-vinyl-1-ethyl-1H-imidazolium 1, 1,1-Trifluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonamide; 3-vinyl-1-methyl-1H-imidazolium 1,1,1-trifluoro-N- [(trifluoromethyl)sulfonyl]methanesulfonamide; 3-vinyl-1-methyl-1H-imidazolium hexafluorophosphate; 3-vinyl-1-methyl-1H-imidazolium 4 - methylbenzenesulfonate; 3-vinyl-1-methyl-1H-imidazolium tetrafluoroborate; 3-vinyl-1-ethyl-1H-imidazolium iodide; 3-vinyl-1 -Ethyl-1H-imidazolium bromide; 3-vinyl-1-ethyl-1H-imidazolium 1,1,1-trifluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonyl Amine; 3-vinyl-1-ethyl-1H-imidazolium hexafluorophosphate; 3-vinyl-1-ethyl-1H-imidazolium tetrafluoroborate; 1,3-divinyl-1H- imidazolium chloride; 1,3-divinyl-1H-imidazolium tetrafluoroborate; 1,3-divinyl-1H-imidazolium hexafluorophosphate; 3-vinyl-1-ethyl-2 - Methyl-1H-imidazolium iodide; 3-vinyl-1,2-dimethyl-1H-imidazolium iodide; 3-vinyl-1,2-dimethyl-1H-imidazolium chloride ; 3-vinyl-2-ethyl-1-methyl-1H-imidazolium iodide; 3-(aminomethyl)-1-vinyl-1H-imidazolium bromide; 3-vinyl-1- (1-Methylethyl)-1H-imidazolium bromide; 3-(1,1-dimethylethyl)-1-vinyl-1H-imidazolium bromide; 3-vinyl-1-propane 1-(2-aminoethyl)-3-vinyl-1H-imidazolium chloride; 1-(cyanomethyl)-3-vinyl-1H-imidazolium bromide compound; 1-[2-(diethylamino)ethyl]-3-vinyl-1H-imidazolium chloride; 3-vinyl-1-(2-propen-1-yl)-1H-imidazolium Chloride; 3-vinyl-1-(2-propen-1-yl)-1H-imidazolium 1,1,1-trifluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonamide ; 3-vinyl-1-(2-propen-1-yl)-1H-imidazolium bromide; 3-vinyl-1-(benzyl)-1H-imidazolium bromide; 1-vinyl- 3-(4-Methylphenyl)-1H-imidazolium chloride; 3-vinyl-1-(2-hydroxyethyl)-1H-imidazolium chloride; 3-vinyl-1-(1- Methylpropyl)-1H-imidazolium chloride; 1-butyl-3-vinyl-1H-imidazolium bromide; 3-vinyl-1-(2-ethoxyethyl)-1H- Imidazolium Bromide; 1-Methyl-3-(2-propen-1-yl)-1H-imidazolium iodide; 1-Methyl-3-(2-propen-1-yl)-1H-imidazolium Chloride; 1-Methyl-3-(2-propen-1-yl)-1H-imidazolium 1,1,1-trifluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonamide ; 1-Methyl-3-(2-propen-1-yl)-1H-imidazolium hexafluorophosphate; 1-Methyl-3-(2-propen-1-yl)-1H-imidazolium tetrafluorophosphate borate; 1-ethyl-3-(2-propen-1-yl)-1H-imidazolium iodide; 2-methyl-3-(2-propen-1-yl)-1-propyl-1H - Imidazolium bromide; 3-(2-propen-1-yl)-1-propyl-1H-imidazolium bromide; 3-(2-hydroxyethyl)-1-(2-propen-1-yl) )-1H-imidazolium bromide; 1-butyl-3-(2-propen-1-yl)-1H-imidazolium bromide; 1,3-di-2-propen-1-yl-1H-imidazole Onium bromide; 1,3-bis-2-propen-1-yl-1H-imidazolium 1,1,1-trifluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonamide; 1 ,3-di-2-propen-1-yl-1H-imidazolium tetrafluoroborate; 3-(2-hydroxyethyl)-1-(2-propen-1-yl)-1H-imidazolium bromide ; 1-(2-cyanoethyl)-3-(2-propen-1-yl)-1H-imidazolium bromide; 1-methyl-3-(2-oxypropyl)-1H- imidazolium tetrafluoroborate; 3-[(4-vinylphenyl)methyl]-1-methyl-1H-imidazolium iodide; 3-[(4-vinylphenyl)methyl]-1 - Methyl-1H-imidazolium chloride; 3-[(4-vinylphenyl)methyl]-1-methyl-1H-imidazolium 1,1,1-trifluoro-N-[(trifluoro Methyl)sulfonyl]methanesulfonamide; 3-[(4-vinylphenyl)methyl]-1-methyl-1H-imidazolium hexafluorophosphate; 3-[(4-vinylbenzene base)methyl]-1-methyl-1H-imidazolium tetrafluoroborate; 3-[(4-vinylphenyl)methyl]-1-ethyl-1H-imidazolium chloride;,1- [(4-Vinylphenyl)methyl]-3-ethyl-1H-imidazolium and 1,1,1-trifluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonamide salt; 1-(3-aminopropyl)-3-[(4-vinylphenyl)methyl]-1H-imidazolium chloride; 1-butyl-3-[(4-vinylphenyl) Methyl]-1H-imidazolium chloride; 1-methyl-3-[[(1-oxy-2-propen-1-yl)oxy]methyl]-1H-imidazolium bromide; 1 -Ethyl-3-[[(1-oxy-2-propen-1-yl)oxy]methyl]-1H-imidazolium iodide; and 1-butyl-3-[[((1- Pendant oxy-2-propen-1-yl)oxy]methyl]-1H-imidazolium iodide. For completeness, such compounds may be present in the compositions of the present invention alone or in combinations of two or more.

Without intending to limit the invention, representative compounds according to formula IV include:

For completeness, NTf2- in the above description represents the bis-trifluoromethanesulfonimidium anion.

Exemplary compounds b2) according to formula V include, but are not limited to: 3-(3-cyanopropyl)-1-methyl-1H-imidazolium 2-acrylate; 3-hexyl-1-methyl-1H- Imidazolium 2-acrylate; 3-hexadecyl-1-methyl-1H-imidazolium 2-acrylate; 3-ethyl-1-methyl-1H-imidazolium 2-methyl-2-acrylic acid salt; 1-methyl-3-(benzyl)-1H-imidazolium 2-methyl-2-acrylate; 3-ethyl-1-methyl-1H-imidazolium 1-[2-[( 1-Oxy-2-propen-1-yl)oxy]ethyl]1,2-phthalate; 3-ethyl-1-methyl-1H-imidazolium 2-methyl-2 -[(1-Oxy-2-propen-1-yl)amino]-1-propanesulfonate; 3-butyl-1-methyl-1H-imidazolium 3-sulfopropyl 2-methyl Alkyl-2-acrylate; 3-ethyl-1-methyl-1H-imidazolium and 2-methyl-2-acrylic acid 2-(phosphonooxy)ethyl ester; 1-methyl-3 - Hexyl-1H-imidazolium 4-vinylbenzenesulfonate; 1-dodecyl-3-vinyl-1H-imidazolium 4-vinylbenzenesulfonate; 3-vinyl-1-hexadecane Alkyl-1H-imidazolium 4-vinylbenzenesulfonate; 1-methyl-3-propyl-1H-imidazolium 4-vinylbenzenesulfonate; and 3-ethyl-1-methyl- 1H-imidazolium 4-(1-methylvinyl)benzenesulfonate. For completeness, such compounds may be present in the compositions of the present invention alone or in combinations of two or more.

Without intending to limit the invention, representative compounds according to Formula V include:

It should be noted that the electrically debondable adhesive formulations may, in certain embodiments, contain both: b1) one or more compounds according to formula IV; and b2) one or more compounds according to formula V. When both are present, the preferred ratio of b1) to b2) is 5:1 to 1:1, eg 4:1 to 2:1.

c) Free radical initiator The compositions of the present invention comprise c) at least one free radical initiator. The composition should conventionally comprise 0.1 to 10 wt.%, eg 0.1 to 5 wt.% or 0.1 to 2.5 wt.% of c) the at least one free radical initiator, based on the total weight of the composition.

Without intending to limit the invention, one exemplary class of free radical initiators suitable for use herein are organic peroxides selected from, for example, cyclic peroxides; diacyl peroxides; dialkyl peroxides Oxides; hydroperoxides; peroxycarbonates; peroxydicarbonates; peroxyesters; and peroxyketals.

Although certain peroxides, such as dialkyl peroxides, have been specifically disclosed as suitable initiators in US Pat. No. 3,419,512 (Lees) and US Pat. No. 3,479,246 (Stapleton) and may actually have utility herein , but hydroperoxides represent the preferred class of initiators of the present invention. Furthermore, although hydrogen peroxide itself can be used, the most desirable polymerization initiators are organic hydroperoxides. For completeness, the definition of hydroperoxide includes substances such as organic peroxides or organic peroxyesters, which decompose or hydrolyze in situ to form organic hydroperoxides: such peroxides and peroxygen Examples of acid esters are cyclohexyl and hydroxycyclohexyl peroxide and tertiary butyl perbenzoate, respectively.

In one embodiment of the present invention, the free radical initiator comprises or consists of at least one hydroperoxide compound represented by the formula: R ^p OOH wherein: R ^p is aliphatic or aromatic containing up to 18 carbon atoms groups, and preferably wherein: R ^p is a C ₁ -C ₁₂ alkyl group, a C ₆ -C ₁₈ aryl group or a C ₇ -C ₁₈ aralkyl group.

As exemplary peroxide initiators which may be used alone or in combination, mention may be made of: cumene hydroperoxide (CHP); p-menthane hydroperoxide; tertiary butyl hydroperoxide (TBH); perbenzoic acid tertiary butyl peroxypivalate; tertiary butyl peroxide; tertiary butyl peroxyacetate; tertiary butyl peroxy-2-hexanoate; tertiary amyl hydroperoxide ; 1,2,3,4-Tetramethylbutyl hydroperoxide; Benzyl peroxide; Dibenzyl peroxide; 1,3-bis(tertiary butylperoxyisopropyl)benzene; Diacetyl oxide; butyl 4,4-bis(tertiary butylperoxy)valerate; p-chlorobenzyl peroxide; tertiary butyl cumene peroxide; ditertiary butyl peroxide ; Dicumyl peroxide; 2,5-Dimethyl-2,5-di-tert-butylperoxyhexane; hex-3-yne; and 4-methyl-2,2-di-tert-butylperoxypentane.

Without intending to limit the invention, yet another exemplary class of free radical initiators suitable for use herein are azo polymerization initiators selected from, for example, azonitriles; azo esters; azoamides; azoamidines ; azo imidazolines; and macromolecular azo initiators.

As representative examples of suitable azo polymerization initiators, mention may be made of: 2,2'-azobis(2-methylbutyronitrile); 2,2'-azobis(isobutyronitrile); 2,2'-azobis(isobutyronitrile); 2'-azobis(2,4-dimethylvaleronitrile); 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile); 1,1'-azo Azobis(cyclohexane-1-carbonitrile); 4,4'-azobis(4-cyanovaleric acid); 2,2'-azobis(2-methylpropionic acid) dimethyl ester; 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide]; 2,2'-azobis(N-butyl-2-methylpropionamide) ; 2,2'-azobis[2-(2-imidazolin-2-yl)propane]dihydrochloride; 2,2'-azobis[2-(2-imidazolin-2-yl) Propane]; 2,2'-azobis(2-methylpropionamidine) dihydrochloride; 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine] Tetrahydrate; 4,4-azobis(4-cyanovaleric acid), a polymer with α,ω-bis(3-aminopropyl)polydimethylsiloxane (VPS-1001, commercially available from Wako Pure Chemical Industries); and 4,4'-azobis(4-cyanovaleric acid) polyethylene glycol polymer (VPE-0201, available from Wako Pure Chemical Industries).

It is not excluded that the compositions of the present invention may comprise at least one free radical photoinitiator compound which upon irradiation with actinic radiation initiates polymerization or hardening of the composition.

In general, free radical photoinitiators are divided into photoinitiators known as "Norrish type I" which form radicals by cleavage and photoinitiators known as "Norrish type II" which form radicals by hydrogen abstraction. These Norrish Type II photoinitiators require a hydrogen donor to act as a source of free radicals: since initiation is based on bimolecular reactions, Norrrish Type II photoinitiators are generally slower than Norrrish Type I photoinitiators based on free-radical unimolecular formation. On the other hand, Norrish type II photoinitiators have better light absorption properties in the near UV spectral region. Those skilled in the art should be able to select an appropriate free radical photoinitiator based on the actinic radiation used in curing and the sensitivity of the photoinitiator at that wavelength.

Preferred free radical photoinitiators are those selected from the group consisting of: benzalkonium phosphine oxide; aryl ketones; benzophenones; hydroxylated ketones; 1-hydroxyphenyl ketones; ketals; and metallocene. For completeness, combinations of two or more of these photoinitiators are not excluded from this invention.

；2-羥基-2-甲基苯丙酮(Daracur 1173)；2-甲基-4-(甲硫基)-2-(N-嗎啉基)苯丙酮；甲基苯基乙醛酸；2-苯甲醯基苯甲酸甲酯；4-(二甲胺基)苯甲酸2-乙基己酯；4-(N,N-二甲胺基)苯甲酸乙酯；苯基雙(2,4,6-三甲基苯甲醯基)氧化膦；二苯基(2,4,6-三甲基苯甲醯基)氧化膦；及苯基(2,4,6-三甲基苯甲醯基)次膦酸乙酯。此外，出於保證，在本發明中並不排除此等光引發劑中之兩者或更多者之組合。Especially preferred free radical photoinitiators are those selected from the group consisting of: benzoin dimethyl ether; 1-hydroxycyclohexyl phenyl ketone; benzophenone; 4-chlorobenzophenone; 4-phenylbenzophenone; 4,4'-bis(diethylamino)benzophenone;4,4'-bis(N,N'-dimethylamino)bis Benzophenone (Michler's ketone); isopropyl 9-oxothio

; 2-Hydroxy-2-methylpropiophenone (Daracur 1173); 2-Methyl-4-(methylthio)-2-(N-morpholinyl)propiophenone; Methylphenylglyoxylic acid; 2 -Methyl benzylbenzoate; 2-ethylhexyl 4-(dimethylamino)benzoate; ethyl 4-(N,N-dimethylamino)benzoate; phenylbis(2, 4,6-trimethylbenzyl)phosphine oxide; diphenyl(2,4,6-trimethylbenzyl)phosphine oxide; and phenyl(2,4,6-trimethylbenzene) carboxy) ethyl phosphinate. Furthermore, for the sake of assurance, combinations of two or more of these photoinitiators are not excluded from the present invention.

In the case of compositions of the present invention comprising free radical photoinitiators, irradiation of these curable compositions will generate reactive species from the photoinitiators, initiating the curing reaction. Once the species is produced, the curing chemical reaction follows the same thermodynamic rules as any chemical reaction: the reaction rate can be accelerated by heating. The practice of using heat treatment to enhance actinic radiation curing of monomers is generally known in the art.

As those skilled in the art will recognize, a photosensitizer can be incorporated into the composition to improve the efficiency with which the photoinitiator c) uses the delivered energy. The term " photosensitizer " as used in its standard meaning refers to any substance that increases the rate of photoinitiated polymerization or shifts the wavelength at which polymerization occurs. The photosensitizer should be used in an amount of 0 to 25 wt.% based on the weight of the free radical photoinitiator.

The use of free-radical (photo)initiators may result in residual compounds in the final cured product from (photo)chemical reactions. These residues can be detected by conventional analytical techniques, such as: infrared, ultraviolet, and NMR spectroscopy; gas or liquid chromatography; and mass spectrometry. Thus, the present invention may comprise a cured matrix (co)polymer and detectable amounts of residues from free radical (photo)initiators. These residues are present in small amounts and generally do not interfere with the desired physicochemical properties of the final cured product.

d) Solubilizer The compositions of the present invention may optionally contain a solubilizer. The composition may contain, for example, 0.1 to 10 wt.% or 0.1 to 5 wt.% of a solubilizer, based on the weight of the composition. The solubilizer has the function of promoting the miscibility of the electrolyte b) in the adhesive composition: the solubilizer may or may not form part of the polymer matrix formed after the adhesive composition is cured, but does help to promote the ion transfer. Therefore, the solubilizer is preferably a polar compound and should preferably be a liquid at room temperature.

Suitable classes of solubilizers include: polyphosphazenes; polymethylene sulfides; polyoxyalkylene glycols; polyethyleneimines; polysiloxane surfactants, such as polyalkylsiloxanes and polyoxyalkylenes Alkyl-modified polydimethylsiloxanes, including but not limited to poly(C2-C3)oxyalkylene-modified polydimethylsiloxanes; functionalized polyalkylsiloxanes and epoxy resins Copolymers of polydimethylsiloxane ( PDMS ) and epoxy resins; polyols; and sugars. For completeness, fluorinated polysiloxane surfactants, such as fluorinated polysilanes, are intended to be encompassed by the term polysiloxane surfactant.

Polyols and sugars such as ethylene glycol, 1,3-propanediol, cyclohexanediol, hydroquinone, catechol, resorcinol, phloroglucinol, pyrogallol, hydroxyhydroquinone, ginseng Methyl) benzene, bis(hydroxymethyl) benzene with three methyl or ethyl substituents bonded to the remaining benzene carbon atoms, isosorbide, isomannide, iditol (isoidide), glycerol, cyclohexane-1,2,4-triol, 1,3,5-cyclohexanetriol, pentane-1,2,3-triol, hexane-1,3,5 -Triol, erythritol, 1,2,4,5-tetrahydroxybenzene, threitol, arabitol, xylitol, ribitol, mannitol, sorbitol, inositol, fructose, glucose , mannose, lactose, 1,1,1-para(hydroxymethyl)propane, 1,1,1-para(hydroxymethyl)ethane, bis(trimethylolpropane), trimethylolpropaneethane Oxylates, 2-hydroxymethyl-1,3-propanediol, neopentaerythritol allyl ether and neotaerythritol.

Among the polyoxyalkylene glycols, it can be noted that it is particularly preferable to use polyoxy(C ₂ -C ₃ )alkylenes having a weight average molecular weight of 200 to 10 000 g/mol, for example 200 to 2000 g/mol glycol.

Additives and adjuvant ingredients The compositions obtained in the present invention will generally further comprise adjuvants and additives which can impart improved properties to these compositions. For example, such adjuvants and additives can impart one or more of the following properties: improved elastic properties; improved elastic recovery; longer start-up time; faster cure time; and lower residual viscosity. Such adjuvants and additives include: non-polymerizable electrolytes; toughening agents; conductive particles; non-conductive fillers; catalysts; plasticizers; stabilizers, including UV stabilizers; antioxidants; reactive diluents; desiccants ; adhesion promoters; fungicides; flame retardants; rheological adjuvants; colorants or pastes; and/or to a lesser extent also optionally non-reactive diluents.

Such adjuvants and additives can be used in desired combinations and proportions, provided that they do not adversely affect the properties and essential characteristics of the composition. Although exceptions may exist in some cases, these adjuvants and additives in total should not constitute more than 20 wt. % of the total composition and preferably should not constitute more than 10 wt. % of the composition.

The presence of non-polymerizable electrolytes in the compositions of the present invention is not excluded. Exemplary electrolytes include non-polymerizable salts of cations selected from the group consisting of: ammonium; pyridinium; phosphonium; imidazolium; oxazolium; guanidinium; and thiazolium. Although the anions of such non-polymerizable salts are not particularly limited, preferred anions are selected from the group consisting of: halide ions; formulae PF ₆ ⁻ , CF ₃ SO ₃ ⁻ , (CF ₃ SO ₃ ) ₂ N ⁻ Pseudohalides and halogen-containing compounds of , CF ₃ CO ₂ ⁻ and CCl ₃ CO ₂ ⁻ ; carboxylate anions, especially formate, acetate, propionate, butyrate and lactate; hydroxycarboxylate anions; pyridine and pyrimidinates; carboxyimides; bis(sulfonyl)imides and sulfonimides; sulfates, especially methosulfate and ethosulfate; sulfites; sulfonates, especially methanesulfonate; and phosphoric acid radicals, especially dimethyl-phosphate, diethyl-phosphate and di-(2-ethylhexyl)-phosphate.

When included in the composition, the non-polymerizable electrolyte should be present in an amount of less than 10 wt. % of the total weight of the polymerizable ionic compound (part b).

The presence of the toughening agent in the compositions of the present invention may facilitate debonding of the cured adhesive. Without wishing to be bound by theory, the toughening agent facilitates phase separation in the cured adhesive under an applied potential. In particular, good release is obtained when the compositions of the present invention comprise at least one toughening agent selected from epoxy resin-elastomer adducts; and toughened rubbers dispersed in the matrix polymer in the form of core-shell particles. Sticky results.

The elastomer-containing adducts can be used alone or a combination of two or more specific adducts can be used. Furthermore, each adduct can be independently selected from a solid adduct or a liquid adduct at a temperature of 23°C. Typically, suitable adducts will be characterized by a weight ratio of epoxy resin to elastomer of 1:5 to 5:1, eg, 1:3 to 3:1. And an instructive reference for suitable epoxy/elastomer adducts is US Patent Publication 2004/0204551. Additionally, exemplary commercial epoxy/elastomer adducts for use herein include, but are not limited to: HYPDX RK8-4, available from CVC Chemical; and B-Tough A3, available from Croda Europe Limited.

, the term " core-shell rubber " or CSR is used according to its standard meaning in the art to denote a rubber particle core formed from a polymer comprising an elastic or rubbery polymer as a main component and polymerized by grafting onto the core shell formed by the polymer. The shell layer partially or completely covers the surface of the rubber particle core during the graft polymerization process. The core should comprise at least 50 wt.% by weight of the core-shell rubber particles.

The polymeric material of the core should have a glass transition temperature (T _g ) not exceeding 0°C, and preferably -20°C or less, more preferably -40°C or less and even more preferably -60°C or less Low glass transition temperature (T _g ). Shell polymers are non-elastomeric, thermoplastic or thermoset polymers having a glass transition temperature (T _g ) above room temperature, preferably above 30°C and more preferably above 50°C.

Without intending to limit the invention, the core may comprise: a diene homopolymer, such as a homopolymer of butadiene or isoprene; a diene copolymer, such as butadiene or isoprene with Copolymers of one or more ethylenically unsaturated monomers such as vinyl aromatic monomers, (meth)acrylonitrile or (meth)acrylates; polymers based on (meth)acrylate monomers such as polybutylacrylate; and polysiloxane elastomers such as polydimethylsiloxane and cross-linked polydimethylsiloxane.

Also, without intending to limit the invention, the shell may comprise a polymer or copolymer of one or more monomers selected from the group consisting of: (meth)acrylates, such as methyl methacrylate; vinyl aromatics Monomers, such as styrene; vinyl cyanide, such as acrylonitrile; unsaturated acids and anhydrides, such as acrylic acid; and (meth)acrylamides. The polymers or copolymers used in the shell may have acid groups which are ionically cross-linked via the formation of metal carboxylates, especially via the formation of salts of divalent metal cations. Shell polymers or copolymers can also be covalently crosslinked by monomers having two or more double bonds per molecule.

Preferably, any included core-shell rubber particles have an average particle size (d50) of 10 nm to 300 nm, such as 50 nm to 250 nm: the particle size refers to the diameter or maximum size of the particles in the particle distribution and is determined by dynamic measured by light scattering. For completeness, this application does not exclude the presence of two or more types of core-shell rubber (CSR) particles with different particle size distributions in the composition to provide a balance of key properties of the resulting cured product, including shear Shear strength, peel strength and resin fracture toughness.

The core-shell rubber can be selected from commercially available products, examples of which include: Paraloid EXL 2650A, EXL 2655, and EXL2691 A, available from Dow Chemical Company; Clearstrength® XT100, available from Arkema Company; Kane Ace, available from Kaneka Company ® MX series; and especially MX 120, MX 125, MX 130, MX 136, MX 551, MX553; and METABLEN SX-006 available from Mitsubishi Rayon.

The compositions of the present invention may contain conductive particles. For example, the composition may contain 0 to 10 wt.% or 0.1 to 5 wt.% of conductive particles by weight of the composition.

Broadly, there is no specific intention to limit the shape of the particles used as conductive fillers: needle-shaped, spherical, elliptical, cylindrical, bead-shaped, cube-shaped or flake-shaped particles can be used alone or in combination. Furthermore, it is envisaged that more than one particle type of agglomerates may be used. Likewise, there is no specific intent to limit the size of particles used as conductive fillers. However, such conductive fillers will conventionally have an average volume particle size of 0.1 to 1500 μm, eg, 1 to 1250 μm, as measured by laser diffraction/scattering methods.

Exemplary conductive particulate fillers include, but are not limited to: silver; copper; gold; palladium; platinum; nickel; gold or silver plated nickel; carbon black; carbon fiber; graphite; aluminum; indium tin oxide; silver plated copper; silver-coated aluminum; metal-coated glass spheres; metal-coated fillers; metal-coated polymers; silver-coated fibers; silver-coated spheres; antimony-doped tin oxide; conductive nanospheres; nanosilver; nanometers rice aluminum; nano copper; nano nickel; carbon nanotubes; and mixtures thereof. Granular silver and/or carbon black are preferably used as conductive fillers.

The compositions of the present invention may optionally contain non-conductive fillers. For example, the composition may contain 0 to 10 wt.% or 0.1 to 5 wt.% of non-conductive particles by weight of the composition.

Broadly, there is no specific intention to limit the shape of the particles used as non-conductive fillers: needle-shaped, spherical, elliptical, cylindrical, bead-shaped, cube-shaped or flake-shaped particles can be used alone or in combination. Furthermore, it is envisaged that more than one particle type of agglomerates may be used. Likewise, there is no specific intent to limit the size of particles used as non-conductive fillers. However, such non-conductive fillers will conventionally have an average volume particle size of 0.1 to 1500 μm, eg, 1 to 1250 μm, as measured by laser diffraction/scattering methods.

Exemplary non-conductive fillers include, but are not limited to: calcium carbonate, calcium oxide, calcium hydroxide (lime powder), precipitated and/or pyrogenic silicic acid, zeolite, bentonite, wollastonite, magnesium carbonate, diatomaceous earth, sulfuric acid Barium, alumina, clay, talc, titanium oxide, iron oxide, zinc oxide, sand, quartz, flint, mica, glass beads, glass powder and other abrasive minerals. Organic fillers may also be used, especially wood fibers, wood flour, sawdust, cellulose, cotton, wood pulp, wood chips, chopped straw, chopped hay, ground walnut husks, and other chopped fibers. Short fibers such as glass fibers, glass filaments, polyacrylonitrile, carbon fibers, Kevlar fibers or polyethylene fibers may also be added.

The pyrolyzed and/or precipitated silicic acid preferably has a BET surface area of 10 to 90 m ² /g. When used, it does not cause any additional increase in the viscosity of the composition according to the invention, but does help strengthen the cured composition.

It is also conceivable to use pyrolyzed and/or precipitated silicic acid as filler with a higher BET surface area, preferably 100 to 250 m ² /g: due to the larger BET surface area, the strengthening is achieved by using a smaller weight fraction of silicic acid Effects of curing compositions.

Hollow spheres with mineral or plastic shells are also suitable as non-conductive fillers. For example, such spheres may be hollow glass spheres commercially available under the tradename Glass Bubbles®. Plastic hollow spheres such as Expancel® or Dualite® can also be used and are described in EP 0 520 426 B1: they are made of inorganic or organic substances and each have a thickness of 1 mm or less, preferably 500 µm or smaller diameter.

Non-conductive fillers that impart thixotropy to the composition may be preferred for many applications: such fillers are also described as rheological adjuvants, such as hydrogenated castor oil, fatty acid amides, or expandable plastics such as PVC.

The desired viscosity of the resulting curable composition can determine the amount of filler used. With regard to the latter consideration, the total amount of fillers (conductive and non-conductive) present in the composition should not prevent the composition from being readily suitable for application to a substrate by the chosen method. For example, a curable composition intended to be extruded by suitable dispensing equipment such as a tube should have a viscosity of 1000 to 150,000, preferably 10,000 to 100,000 mPas.

For the purposes of the present invention, a " plasticizer " is a substance that reduces the viscosity of a composition and thus promotes its processability. The plasticizers herein may comprise up to 10 wt.% or up to 5 wt.% based on the total weight of the composition and are preferably selected from the group consisting of: diurethanes; monofunctional, linear or Ethers of branched C4-C16 alcohols, such as Cetiol OE (available from Cognis Deutschland GmbH, Düsseldorf); esters of rosin acid, butyric acid, thiobutyric acid, acetic acid, propionic acid and citric acid; based on nitrocellulose and polyvinyl acetate Esters of Esters; Fatty Acid Esters; Dicarboxylates; Esters Carrying OH Groups or Epoxidized Fatty Acids; Glycolates; Benzoates; Phosphates; polystyrene; hydrocarbon plasticizers; chlorinated paraffins; and mixtures thereof. It should be noted that, in principle, phthalates can be used as plasticizers, but these are not preferred due to their toxicological potential.

For the purposes of the present invention, " stabilizers " are to be understood as antioxidants, UV stabilizers, thermal stabilizers or hydrolytic stabilizers. Herein, the stabilizers may amount to up to 10 wt.% or up to 5 wt.%, based on the total weight of the composition. Standard commercial examples of stabilizers suitable for use herein include: hindered phenols; thioethers; benzotriazoles; benzophenones; benzoates; cyanoacrylates; acrylates; hindered amine light stabilizers ( Amines of the HALS) type; phosphorus; sulfur; and mixtures thereof.

It should be noted that compounds having metal chelating properties can be used in the compositions of the present invention to help enhance the adhesion of the cured adhesive to the substrate surface. In addition, an acetoacetate functional modified resin sold by King Industries under the tradename K-FLEX XM-B301 is also suitable as an adhesion promoter.

In order to increase the shelf life even further, it is often desirable to further stabilize the compositions of the present invention with respect to moisture penetration through the use of desiccants. It is also sometimes necessary to reduce the viscosity of the adhesive compositions according to the invention for specific applications by using reactive diluents. The total amount of reactive diluent present will typically be from 0 to 10 wt.%, such as 0.1 to 5 wt.%, based on the total weight of the composition.

Insofar as the presence of solvents and non-reactive diluents can effectively adjust the viscosity of the compositions of the present invention, their presence in the compositions of the present invention is not excluded. By way of example, but only by way of illustration, the compositions may contain one or more of the following: xylene; 2-methoxyethanol; dimethoxyethanol; 2-ethoxyethanol; 2-propane Oxyethanol; 2-isopropoxyethanol; 2-butoxyethanol; 2-phenoxyethanol; 2-benzyloxyethanol; benzyl alcohol; ethylene glycol; ethylene glycol dimethyl ether; Alcohol diethyl ether; ethylene glycol dibutyl ether; ethylene glycol diphenyl ether; diethylene glycol; diethylene glycol-monomethyl ether; diethylene glycol-monoethyl ether; diethylene glycol-mono-n-butyl ether ; Diethylene glycol dimethyl ether; Diethylene glycol diethyl ether; Diethyl ether Diethylene glycol di-n-butyl ether; Propylene glycol butyl ether; Propylene glycol phenyl ether; Methyl ether; dipropylene glycol di-n-butyl ether; N-methylpyrrolidone; diphenylmethane; diisopropylnaphthalene; petroleum fractions such as Solvesso® products (available from Exxon); alkylphenols such as tris Butylphenol, nonylphenol, dodecylphenol and 8,11,14-pentadecatrienylphenol; styrenated phenol; bisphenol; aromatic hydrocarbon resins, especially resins containing phenolic groups, such as ethoxylates Alkylated or propoxylated phenols; adipates; sebacates; phthalates; benzoates; organophosphates or sulfonates; and sulfonamides.

In addition to the above, the non-reactive diluents preferably together constitute at most less than 10 wt.%, especially less than 5 wt.% or less than 2 wt.%, based on the total weight of the composition.

method and application To form the composition, the above-mentioned parts are brought together and mixed. It is important that the mixing results in a homogeneous distribution of the polymerizable electrolyte, compounds b1) and/or b2) in the adhesive composition: this sufficient and effective mixing determines the homogeneous distribution of the charged species in the polymer matrix obtained after curing , and thereby provide sufficient ionic conductivity to support electrochemical reactions at the interface with the conductive substrate.

As is known in the art, in order to form a one-component (1K) curable composition, the components of the composition are brought together and homogeneously mixed under conditions that inhibit or prevent the reaction of the reactive components: such conditions will readily be understood by those skilled in the art. Therefore, it is generally preferred that the curing agent components are not mixed manually, but are mixed in predetermined amounts by a machine (static or dynamic mixer), eg, under anhydrous conditions without intentional light.

For two-component (2K) compositions, the reactive components are brought together and mixed in a manner that induces their hardening. For one-component (1K) and two-component (2K) compositions, the reactive compounds should be mixed under sufficient shear to obtain a homogeneous mixture. This is believed to be achievable without special conditions or special equipment. That is, suitable mixing devices may include: static mixing devices; magnetic stir bar devices; wire whisk devices; auger; batch mixers; planetary mixers; C.W. Brabender or Banburry® type mixers; and high shear mixers, such as blade-type blenders and rotating impellers.

For small liner applications typically used in volumes less than 2 liters, the preferred packaging for the two-component (2K) composition would be a side-by-side twin or coaxial cartridge, where the two tubular chambers are arranged side-by-side or within each other and used Piston Seals: These pistons are driven to extrude the components from the barrel, preferably through tightly mounted static or dynamic mixers. For larger volume applications, the two components of the composition may advantageously be stored in drums or buckets: in this case, the two components are extruded via a hydraulic press, especially by means of follower plates, and supplied via pipes To the mixing equipment, which ensures a fine and highly homogeneous mixing of the hardener and binder components. In any event, for any package, the important adhesive components are handled to be airtight and moisture tight so that both components can be stored for extended periods of time, ideally 12 months or more.

Non-limiting examples of two-component dispensing apparatus and methods that may be suitable for use in the present invention include those described in US Pat. No. 6,129,244 and US Pat. No. 8,313,006.

Where applicable, two-component (2K) compositions should broadly be formulated to exhibit an initial viscosity (measured immediately after mixing, eg, up to two minutes after mixing) that does not interfere with the method of applying the composition to a substrate. In addition, the two-component (2K) composition should be further formulated to exhibit a pot life of at least 30 minutes and usually at least 60 or 120 minutes, the " pot life " being that the viscosity of the curable composition reaches at 20°C and 50°C Time required for a value of 2 times the viscosity of a freshly mixed curable composition at % relative humidity.

According to the broadest process aspect of the present invention, the composition described above is applied to a substrate and then cured in situ. Before applying the compositions, it is often advisable to pretreat the relevant surface to remove foreign matter therefrom: if applicable, this step may aid the subsequent adhesion of the composition thereto. Such treatments are known in the art and can be performed in a single-stage or multi-stage manner, by, for example, using one or more of the following: an etching treatment with an acid suitable for the substrate and an optional oxidizing agent; Sonic treatment; plasma treatment, including chemical plasma treatment, corona treatment, atmospheric plasma treatment, and flame plasma treatment; immersion in water-based alkaline degreasing baths; treatment with aqueous cleaning emulsions; with cleaning solvents such as tetrachloride carbon or trichloroethylene; and water rinse, preferably deionized or demineralized water. In those cases where a water-based alkaline degreasing bath is used, any degreaser remaining on the surface should preferably be removed by rinsing the substrate surface with deionized or demineralized water.

In some embodiments, the adhesion of the coating composition of the present invention to a preferably pretreated substrate can be promoted by applying a primer thereto. While those skilled in the art will be able to select a suitable primer, instructive references for primer selection include, but are not limited to: US Pat. No. 3,671,483; US Pat. No. 4,681,636; US Pat. No. 4,749,741; US Pat. 4,147,685; and US Patent No. 6,231,990.

The composition is then applied to the preferably pretreated, optionally primed substrate surface by conventional coating methods such as: brushing; rolling, where the composition is solvent-free In the case of using, for example, 4-coat roll equipment or for solvent-containing compositions, for example, 2-coat roll equipment; knife coating; printing methods; and spraying methods, including but not limited to air atomized spraying, air-assisted spraying, Airless spray and high volume low pressure spray.

As indicated above, the present invention provides a bonding structure comprising: a first material layer having a conductive surface; and a second material layer having a conductive surface, wherein cured as defined above and in the scope of the appended claims An electrochemically debonded adhesive composition is disposed between the first material layer and the second material layer. To make such structures, an adhesive composition can be applied to at least one inner surface of the first and/or second material layer and the two layers are then brought into contact under applied pressure, as appropriate, such that the adhesion can be electrically debonded The agent composition is interposed between the two layers.

It is recommended that the composition be applied to the surface at a wet film thickness of 10 to 5000 μm, eg 50 to 2500 μm. Applying thinner layers within this range is more economical and offers the potential to reduce detrimental thicker cured areas. However, the application of thinner coatings or layers must be strictly controlled to avoid the formation of discontinuous cured films and short contacts.

The curing of the coating composition of the present invention is usually carried out at a temperature in the range of 40°C to 200°C, preferably 50°C to 190°C, and especially 60°C to 180°C. Suitable temperatures depend on the particular compound present and the desired cure rate, and can be determined in individual cases by those skilled in the art, using simple preliminary tests if necessary. Of course, curing at lower temperatures within the aforementioned ranges is advantageous because it does not require significant heating or cooling of the mixture from the ambient temperature that typically prevails. However, where applicable, the temperature of the mixture formed from the individual components of the composition may be raised above the mixing temperature and/or coating temperature using conventional means including microwave induction.

The invention will be described with reference to the accompanying drawings in which: Figure 1a depicts a bonding structure according to a first embodiment of the present invention. Figure 1b depicts a bonding structure according to a second embodiment of the present invention. Figure 2a depicts the initial debonding of the structure of the first embodiment after applying a voltage to the structure. Figure 2b depicts the initial debonding of the structure of the second embodiment after applying a voltage to the structure.

As shown in the accompanying Figure 1a, an adhesive structure is provided in which a cured adhesive layer (10) is disposed between two conductive substrates (11). A layer of non-conductive material (12) may be disposed on the conductive substrate (11) to form a more complex bonding structure as depicted in Figure 1b. The layers of the conductive substrate (11) are in electrical contact with a power source (13) which may be a battery or an AC driven direct current (DC) source. The positive and negative terminals of the power supply (13) are shown in a fixed location, but those skilled in the art will of course recognize that the polarity of the system can be reversed.

The two conductive substrates ( 11 ) are presented in the form of layers which may consist in particular of: metal films; metal grids or grids; deposited metal particles; . As exemplary conductive elements, mention may be made of silver filaments, single-walled carbon nanotubes and multi-walled carbon nanotubes. As exemplary conductive oxides, mention may be made of doped indium oxides, such as indium tin oxide (ITO); doped zinc oxide; antimony tin oxide; cadmium stannate; and zinc stannate. In addition to the choice of conductive material, those skilled in the art will recognize the efficacy of the debonding operation where the conductive substrate (11) is in the form of a grid or mesh that provides limited contact with the cured adhesive layer (10). may be weakened.

When a voltage is applied between the respective conductive substrates (11), current is supplied to the adhesive composition (10) disposed therebetween. This initiates electrochemical reactions at the interface of the substrate (11) and the adhesive composition, these electrochemical reactions being understood as oxidation at the positively charged or anode interface and reduction at the negatively charged or cathode interface. These reactions are believed to weaken the adhesive bond between the substrates so that the debondable composition can be easily removed from the substrates.

For illustrative purposes only, as depicted in Figures 2a and 2b, debonding occurs at the positive interface, ie the interface between the adhesive composition (10) and the conductive surface (11) in electrical contact with the positive electrode . By reversing the direction of the current flow before separating the substrates, the adhesive bond at the interface of the two substrates can be weakened.

It should be noted, however, that the composition of the adhesive layer (10) can be adjusted such that debonding occurs at the positive interface or the negative interface or from both. For some embodiments, applying a voltage across the two surfaces to form the anodic and cathodic interfaces will cause debonding to occur at both the anodic and cathodic adhesive/substrate interfaces simultaneously. In an alternative embodiment, if the composition is not responsive to direct current at both interfaces, then opposite polarities can be used to debond both substrate/adhesive interfaces simultaneously. The current can be applied in any suitable waveform, subject to the limitation that debonding is allowed for a sufficient total time at each polarity. In this regard, sinusoidal, rectangular and triangular waveforms may be suitable and may be applied by controlled voltage or controlled current sources.

Without intending to limit the present invention, it is believed that the debonding operation can be effectively performed when at least one and preferably both of the following conditions are activated: a) The applied voltage is 1 to 100 V, such as 20 to 50 V ; and b) applying the voltage for 1 second to 180 minutes, eg, 1 second to 30 minutes. In the case where the peeling of the conductive substrate from the cured adhesive is facilitated by the application of a force, such as through a weight or a spring, the potential may only need to be applied for a few seconds.

The following examples illustrate the invention and are not intended to limit the scope of the invention in any way.

EXAMPLES The following materials and their abbreviations are used in the examples: MMA: methyl methacrylate MAA: methacrylic acid EGDMA: ethylene glycol dimethacrylate PEG-MEA: polyethylene glycol methyl ether acrylate BENZYL MA: Benzyl methacrylate HEMA: (Hydroxyethyl) methacrylate IBOA: Iso(hydroxyethyl) methacrylate AIBN: Azobisisobutyronitrile, available from Sigma Aldrich BPO: Benzyl peroxide, available from PanReac AppliChem HEXMIM StSO3: 3-Methyl-1-hexyl-1H-imidazolium 4-vinylbenzenesulfonate EMIM acrylate: 1-ethyl-3-methyl-1H-imidazolium acrylate ViEIM NTf2: 3-Ethylene yl-1-ethyl-1H-imidazolium 1,1,1-trifluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonamide BMIM NTf2: 3-methyl-1-butyl- 1H-imidazolium 1,1,1-trifluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonamide PEG400: polyethylene glycol available from Sigma Aldrich. CN966H90: An aliphatic polyester urethane diacrylate oligomer blended with 10% 2(2-ethoxyethoxy)ethyl acrylate available from Sartomer SR9054: Available from Sartomer Acid Acrylate Adhesion Promoters Preparation of a first set of formulations: Formulations EDA1 to Formulations EDA14 plus Controls 1, 2 and 3 described in Tables 1a and 1b below were formed with mixing. Table 1a Element Control 1 (g) EDA1 (g) EDA2 (g) EDA3 (g) EDA4 (g) EDA5 (g) EDA6 (g) EDA7 (g) EDA8 (g) MMA 0.780 0.780 0.780 0.780 0.780 0.780 0.780 0.780 0.780 MAA 0.100 0.100 0.100 0.100 0.100 0.100 0.100 0.100 0.100 EGDMA 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 PEG-MEA 0.100 0.100 0.100 0.100 0.100 0.100 0.100 0.100 0.100 AIBN 0.061 0.073 0.073 0.077 0.069 0.065 0.069 0.069 0.061 HEXMIM StSO3 0.623 (1.78 mmol) 0.208 (0.59 mmol) 0.104 (0.30 mmol) 0.052 (0.15 mmol) 0.208 (0.59 mmol) 0.312 (0.89 mmol) ViEIM NTf2 0.717 (1.78 mmol) 0.717 (1.78 mmol) 0.359 (0.89 mmol) 0.180 (0.44 mmol) 0.240 (0.59 mmol) 0.120 (0.30 mmol) Copolymer PE 0.463 (1.16 mmol) Table 1b Element EDA9 (g) EDA10 (g) EDA11 (g) EDA12 (g) Control 2 (g) EDA13 (g) Control 3 (g) EDA14 (g) MMA 0.780 0.780 0.780 0.780 0.630 0.630 MAA 0.100 0.100 0.100 0.100 0.100 0.100 0.100 0.100 EGDMA 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 PEG-MEA 0.100 0.100 0.100 0.100 0.100 0.100 0.100 0.100 BENZYL MA 0.780 0.780 0.150 0.150 AIBN 0.061 0.061 0.061 0.073 0.039 0.047 0.057 0.065 HEXMIM StSO3 0.052 (0.15 mmol) 0.052 (0.15 mmol) 0.052 (0.15 mmol) 0.105 0.105 ViEIM NTf2 0.179 (0.44 mmol) 0.179 (0.44 mmol) 0.179 (0.44 mmol) 0.359 0.359 BMIM NTf2 0.012 0.20 carbon black 0.012 PEG-400 0.012

The parenthesized amounts of the polymerizable electrolytes given in Table 1a and Table 1b are in millimoles (mmol).

Controls 1, 2 and 3 consisted of non-ionic matrix monomers forming the adhesive without any ionic species. Formulations EDA1 to EDA7, EDA9 to EDA11 and EDA13 to EDA14 are based on the copolymerization of nonionic matrix monomers with polymerizable ionic compounds.

EDA8 is a blend of non-ionic matrix monomers and cured polymerizable electrolyte (PE) copolymers and was obtained as follows: First, ViEIM NTf2 (0.359 g) and HexMIM StSO3 (0.104 g) were mixed with azobisisobutyronitrile (0.008 g) mixed at high speed at 3600 rpm for 1 minute; then the mixture was cured at 80°C for 15 minutes; then the mixture was cured at 120°C for 2 hours; and finally, the cured mass was mixed with the non-ionic matrix monomer and Azobisisobutyronitrile mix.

EDA12 forms a reference and is based on a mixture of non-ionic matrix monomers and non-polymerizable ionic compounds (BMIM NTf2).

The coated substrates used for the following formulations EDA1 to EDA14 and the control were aluminum (AA6016) with a thickness of 1.25 mm and the coating of the coating composition was performed using glass beads 100 to 200 microns in diameter as spacers. The substrates were cut into samples with dimensions of 2.5 cm x 10 cm for tensile testing. Based on ISO 4587 ( Adhesives - Determination of tensile lap - shear strength of rigid - to - rigid bonded assemblies ) at room temperature ( International Organization for Standardization) (International Organization for Standardization, 2003) for tensile lap shear (TLS) testing. The bonding overlap area of each of the substrates is 2.5 cm×1.0 cm, and the bonding thickness is 0.1 cm (40 mil). An INSTRON 3366 with a 10 kN load cell was used.

The applied adhesive composition was cured at the overlapping area by applying a temperature of 80°C for 15 minutes and a temperature of 120°C for 120 minutes. The bonded structures were then stored at room temperature for 24 hours prior to initial tensile testing.

Example 1 Tensile lap shear strength was investigated before and after applying a constant potential of 50 V on the adhesive layer for 30 minutes after the 24 hour storage period. The results are reported in Table 2 below. Table 2 adhesive Initial bond strength (MPa) 50 V , adhesive strength after 30 minutes ( MPa ) Control 1 2.03 (± 0.59) 2.11 (± 0.28) EDA1 3.67 (± 0.56) 3.15 (± 0.06) EDA2 2.18 (± 0.36) 1.48 (± 0.20) EDA3 3.44 (± 0.31) 0 EDA4 3.07 (± 0.58) 0.71 (± 0.62) EDA5 2.63 (± 0.51) 1.10 (± 0.23) EDA6 2.66 (± 0.34) 1.71 (± 0.12) EDA7 3.85 (± 0.71) 2.80 (± 0.63) EDA8 2.09 (± 0.13) 2.08 (± 0.33) EDA9 2.61 (± 0.09) 0.97 (± 0.09) EDA10 1.98 (± 0.41) 0 EDA11 2.35 (± 0.11) 0 EDA12 (reference) 1.60 (± 0.60) 0 Control 2 1.76 (± 0.77) 1.17 (± 0.61) EDA13 2.60 (± 0.54) 1.54 (± 0.12) Control 3 1.53 (± 0.63) 2.32 (± 0.45) EDA14 2.67 (± 0.86) 0

Formulations containing polymerizable ionic compounds increase initial adhesive strength. The bond strength of formulations based on the copolymerization of polymerizable ionic compounds and non-ionic matrix monomers decreases after application of a voltage.

Example 2 This example studies the electrical composition of the above adhesive formulation EDA5 by measuring the tensile lap shear strength before and after applying different constant potentials on the adhesive layer for 30 minutes after the 24 hour storage period. layer behavior. The results are reported in Table 3 below. table 3 adhesive Initial bond strength (MPa) 20 V , adhesive strength after 30 minutes ( MPa ) 50 V , adhesive strength after 30 minutes ( MPa ) 80 V , bond strength after 30 minutes ( MPa ) control 2.03 (± 0.59) 2.11 (± 0.28) EDA5 2.63 (± 0.51) 1.59 (± 0.22) 1.10 (± 0.23) 0

Example 3 This example was studied by measuring the tensile lap shear strength before and after applying a constant potential of 50 V on the adhesive layer for 30 minutes after the 24 hour storage period and after the 2 month storage period The electrical delamination behavior of the above adhesive. The results are reported in Table 4 below. Table 4 adhesive Initial bond strength (MPa) 50 V , adhesive strength after 30 minutes ( MPa ) Bonding strength after 2 months of aging ( MPa ) Adhesion strength ( MPa ) after aging for 2 months , 50 V , 30 minutes control 2.03 (± 0.59) 2.11 (± 0.28) EDA5 2.63 (± 0.51) 1.10 (± 0.23) 2.34 (± 0.03) 0.97 (± 0.42) EDA11 2.35 (± 0.11) 0 2.30 (± 0.26) 0 EDA12 (reference) 1.60 (± 0.60) 0 0 0

Formulations based on the copolymerization of non-ionic matrix monomers and polymerizable ionic compounds maintained initial bond strength after two months and still showed a reduction in bond strength after voltage application.

Preparation of a second set of formulations: Formulations EDA15 to EDA19 plus control 4 described in Table 5 below were formed with mixing. table 5 Element Control 4 (g) EDA15 (g) EDA16 (g) EDA17 (g) EDA18 (g) Reference EDA19 (g) CN966H90 0.600 0.600 0.600 0.600 0.600 0.600 HEMA 0.340 0.340 0.340 0.340 0.340 IBOA 0.340 SR9054 0.060 0.060 0.060 0.060 0.060 0.060 BPO 0.040 0.040 0.040 0.040 0.040 0.040 HEXMIM StSO3 0.208 0.208 0.312 EMIM Acrylate 0.108 ViEIM NTf2 0.717 0.717 0.717 ViEIM MMS 0.760 BMIM NTf2 0.231

The control 4 consisted of a non-ionic matrix monomer forming an adhesive and did not contain any ionic species. Formulations EDA15 to EDA18 are based on the copolymerization of non-ionic matrix monomers with polymerizable ionic compounds.

EDA19 forms a reference and is based on a mixture of a non-ionic matrix monomer and a non-polymerizable ionic compound (BMIM NTf2).

Coated substrates for the following formulations EDA15 to EDA19 and control 4 were aluminum (AA6016) 1.25 mm thick and stainless steel (1.4301) 1.5 mm thick and glass beads 100 to 200 microns in diameter were used as spacers The coating of the coating composition is carried out. The substrates were cut into 2.5 cm x 10 cm (1" x 4") samples for tensile testing. Tensile Lap Shear (TLS) tests were performed at room temperature based on ISO 4587 ( Adhesives - Determination of Tensile Lap Shear Strength of Rigid-to-Rigid Bonded Assemblies ) (International Organization for Standardization, 2003). The bonding overlap area of each of the substrates is 2.5 cm×1.0 cm, and the bonding thickness is 0.1 cm (40 mil). A Zwick Z020 with a 20 kN load cell was used.

The applied adhesive composition was cured at the overlapping area by applying a temperature of 80°C for 15 minutes and a temperature of 120°C for 30 minutes. The bonded structures were then stored at room temperature for 24 hours prior to initial tensile testing.

Example 4 Tensile lap shear strength was studied before and after a constant potential of 50 V was applied to the adhesive layer for 30 minutes after the 24 hour storage period. The results are reported in Table 6 below. Table 6 adhesive aluminum Stainless steel Initial bond strength (MPa) 50 V , adhesive strength after 30 minutes ( MPa ) Initial bond strength (MPa) 50 V , adhesive strength after 30 minutes ( MPa ) Control 4 11.02 (± 0.39) 11.19 (± 0.46) 11.05 (± 0.54) 10.58 (± 0.10) EDA15 12.38 (± 0.64) 0 9.19 (± 1.03) 0 EDA16 9.76 (± 0.17) 4.39 (± 0.12) Not measured Not measured EDA17 5.82 (± 0.14) 0 Not measured Not measured EDA18 10.54 (± 0.04) 2.86 (± 0.03) Not measured Not measured EDA19 6.03 (± 0.39) 0 6.46 (± 0.62) 0

Formulations EDA15 and EDA18 containing the polymerizable ionic compound maintained initial bond strength, while formulation EDA17 showed a decrease in initial strength. The initial strength of formulation EDA19 containing the non-polymerizable ionic liquid was reduced by 50%. The bond strength of formulations based on the copolymerization of polymerizable ionic compounds and non-ionic matrix monomers decreases after application of a voltage.

Example 5 This example was performed by applying a constant potential of 50 V on the adhesive layer for 30 minutes before and after the 24 hour storage period and after the 1 week, 1 month, 2 months and 3 month storage periods The tensile lap shear strength was then measured to study the electrical delamination behavior of some of the above adhesives (EDA15 vs. EDA19). The air-conditioned chamber used was set at 23°C and 50% relative humidity. The results are reported in Tables 7 and 8 below. Table 7 aluminum storage time EDA15 EDA19 Initial bond strength (MPa) 50 V , adhesive strength after 30 minutes ( MPa ) Bonding strength after 2 months of aging ( MPa ) Adhesion strength ( MPa ) after aging for 2 months , 50 V , 30 minutes initial 12.38 (± 0.64) 0 6.03 (± 0.39) 0 1 week 12.45 (± 0.56) 0 5.83 (± 0.38) 0 1 month 10.00 (± 0.88) 0 4.48 (± 0.95) 0 2 months 10.94 (± 0.20) 0 4.18 (± 0.16) 0 3 months 11.03 (± 1.43) 0 Not measured Not measured Table 8 Stainless steel storage time EDA15 EDA19 Initial bond strength (MPa) 50 V , adhesive strength after 30 minutes ( MPa ) Bonding strength after 2 months of aging ( MPa Aging , 50 V for 2 months , bond strength after 30 minutes ( MPa ) initial 9.19 (± 1.03) 0 6.46 (± 0.62) 0 1 week 9.38 (± 0.69) 0 5.46 (± 0.33) 0 1 month 9.09 (± 1.75) 0 4.25 (± 0.30) 0 2 months 8.51 (± 0.51) 0 4.58 (± 0.21) 0 3 months 8.13 (± 0.28) 0 Not measured Not measured

Formulation EDA15 based on the copolymerization of non-ionic matrix monomers and polymerizable ionic compounds showed a slight decrease in bond strength (12%) after three months. Formulations based on mixtures of non-polymerizable ionic liquids and non-ionic matrix monomers showed a greater reduction in bond strength of 30% to both aluminum and stainless steel after two months. All formulations showed a decrease in bond strength upon application of voltage.

In view of the foregoing description and examples, it will be apparent to those skilled in the art that equivalent modifications may be made thereto without departing from the scope of the claimed scope.

10: Curing the adhesive layer/adhesive composition 11: Conductive substrate/conductive surface 12: Non-conductive material layer 13: Power

The invention will be described with reference to the accompanying drawings in which: Figure 1a depicts a bonding structure according to a first embodiment of the present invention. Figure 1b depicts a bonding structure according to a second embodiment of the present invention. Figure 2a depicts the initial debonding of the structure of the first embodiment after applying a voltage to the structure. Figure 2b depicts the initial debonding of the structure of the second embodiment after applying a voltage to the structure.

Claims (15)

A curable and electrochemically debonded adhesive composition comprising, by weight of the composition: 40 to 99 wt.% of a) at least one ethylenically unsaturated nonionic monomer; 0.9 to 50 wt % of b) at least one polymerizable ionic compound, wherein the polymerizable ionic compound comprises: b1) at least one compound according to general formula IV:

and/or b2) at least one compound according to general formula V:

Wherein: R ⁷ is selected from: C ₁ -C ₃₀ alkyl; C ₂ -C ₈ alkenyl; C ₁ -C ₃₀ heteroalkyl _; C ₃ -C ₃₀ cycloalkyl; C ₆ -C ₁₈ aryl; C ₁ -C ₉ heteroaryl _; C ₇ -C ₁₈ alkaryl _; C ₂ -C ₅ heterocycloalkyl; or -R ^a -C(=O)-R ^b , where R ^a is C ₁ -C ₆ alkylene and R ^b is C ₁ -C ₆ alkyl; each R ⁸ is independently selected from H, C ₁ -C ₁₈ alkyl, C ₁ -C ₁₈ heteroalkyl, C ₃ -C ₁₈ cycloalkane base, C ₆ -C ₁₈ aryl, C ₁ -C ₉ heteroaryl _, C ₇ -C ₁₈ alkaryl or C ₂ -C ₅ heterocycloalkyl; R ⁹ is H or C ₁ -C ₄ alkyl ; each R ¹⁰ is independently selected from: C ₁ -C ₃₀ alkyl; C ₁ -C ₃₀ heteroalkyl _; C ₃ -C ₃₀ cycloalkyl; C ₆ -C ₁₈ aryl; C ₁ -C ₉ heteroalkyl Aryl _; C ₇ -C ₁₈ alkaryl _; C ₂ -C ₅ heterocycloalkyl; or -R ^a -C(=O)-R ^b , wherein R ^a is C ₁ -C ₆ alkylene and R ^b is a _C1 - _C6 alkyl group; A is a non-polymerizable anion; T is an ethylenically unsaturated anion; d and m are each an integer having a value of at least 1; value; and,

is a covalent bond, C ₁ -C ₂ alkylene, -CH ₂ OC(=O)-, -CH ₂ CH ₂ OC(=O)-, p-benzyl or p-tolyl; and, 0.1 to 10 wt.% of c) at least one free radical initiator. The adhesive composition of claim 1, comprising: 45 to 95 wt.% of a) the at least one ethylenically unsaturated nonionic monomer; 5 to 30 wt.% of b) the at least one polymerizable ionic compound; 0.1 to 5 wt.% of c) the at least one free radical initiator; and, 0 to 10 wt.% of d) solubilizers. The adhesive composition of claim 1 or 2, wherein part a) comprises 40 to 95 wt.% of a1) at least one (meth)acrylate monomer represented by formula I, based on the weight of the composition: H ₂ C=CGCO ₂ R ¹ (I) wherein: G is hydrogen, halogen or C ₁ -C ₄ alkyl; and, R ¹ is selected from: C ₁ -C ₃₀ alkyl; C ₂ -C ₃₀ heteroalkane C ₃ -C ₃₀ cycloalkyl; C ₂ -C ₈ heterocycloalkyl; C ₂ -C ₂₀ alkenyl; and C ₂ -C ₁₂ alkynyl. The adhesive composition of any one of claims 1 to 3, wherein part a) comprises up to 50 wt.%, preferably 5 to 25 wt.% of a3) at least one (a base) acrylate functional oligomers. The adhesive composition of any one of claims 1 to 4, wherein part a) comprises at least one α,β-ethylenically unsaturated monocarboxylic acid having 3 to 5 carbon atoms. The adhesive composition of any one of claims 1 to 5, wherein in part b): R ⁷ is selected from: C ₁ -C ₈ alkyl; C ₂ -C ₄ alkenyl; C ₁ -C ₈ C ₃ -C ₁₂ cycloalkyl _; C ₆ -C ₁₈ aryl; C ₁ -C ₉ heteroaryl _; C ₇ -C ₁₈ alkaryl _; C ₂ -C ₅ heterocycloalkyl; or -R ^a -C(=O)-R ^b , wherein R ^a is a C ₁ -C ₄ alkylene and R ^b is a C ₁ -C ₄ alkylene; each R ⁸ is preferably independently selected from H or C ₁ -C ₂ alkyl; R ⁹ is H or methyl; and, R ¹⁰ is selected from C ₁ -C ₈ alkyl; C ₁ -C ₈ heteroalkyl; C ₃ -C ₁₂ cycloalkyl; C _{6 -} C ₁₈ aryl; C ₁ -C ₉ heteroaryl _; C ₇ -C ₁₈ alkaryl _; C ₂ -C ₅ heterocycloalkyl; or -R ^a -C(=O)-R ^b , where R ^a is C ₁ -C ₄ alkylene and R ^b is C ₁ -C ₄ alkyl. The adhesive composition of any one of claims 1 to 5, wherein part b) comprises: b1) at least one compound selected from the group consisting of: 3-vinyl-1-methyl-1H-imidazolium iodide; 3-vinyl-1-methyl-1H-imidazolium chloride; 3-ethene 3-Vinyl-1-methyl-1H-imidazolium bromide; 3-vinyl-1-methyl-1H-imidazolium methanesulfonate; 3-vinyl-1-methyl-1H-imidazolium 1,1 ,1-Trifluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonamide; 3-vinyl-1-ethyl-1H-imidazolium 1,1,1-trifluoro-N-[ (Trifluoromethyl)sulfonyl]methanesulfonamide; 3-vinyl-1-methyl-1H-imidazolium hexafluorophosphate; 3-vinyl-1-methyl-1H-imidazolium 4- Methylbenzenesulfonate; 3-vinyl-1-methyl-1H-imidazolium tetrafluoroborate; 3-vinyl-1-ethyl-1H-imidazolium iodide; 3-vinyl-1- Ethyl-1H-imidazolium bromide; 3-vinyl-1-ethyl-1H-imidazolium 1,1,1-trifluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonamide ; 3-vinyl-1-ethyl-1H-imidazolium hexafluorophosphate; 3-vinyl-1-ethyl-1H-imidazolium tetrafluoroborate; 3-vinyl-1-(1-methyl) ethyl)-1H-imidazolium bromide; 3-(1,1-dimethylethyl)-1-vinyl-1H-imidazolium bromide; 3-vinyl-1-propyl-1H- imidazolium bromide; 3-vinyl-1-(benzyl)-1H-imidazolium bromide; 1-vinyl-3-(4-methylphenyl)-1H-imidazolium chloride; 3- Vinyl-1-(1-methylpropyl)-1H-imidazolium chloride; 1-butyl-3-vinyl-1H-imidazolium bromide; 3-[(4-vinylphenyl)methanium base]-1-methyl-1H-imidazolium iodide; 3-[(4-vinylphenyl)methyl]-1-methyl-1H-imidazolium chloride; 3-[(4-vinyl) Phenyl)methyl]-1-methyl-1H-imidazolium 1,1,1-trifluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonamide; 3-[(4-ethene phenyl)methyl]-1-methyl-1H-imidazolium hexafluorophosphate; 3-[(4-vinylphenyl)methyl]-1-methyl-1H-imidazolium tetrafluoroborate ; 3-[(4-Vinylphenyl)methyl]-1-ethyl-1H-imidazolium chloride; 1-[(4-vinylphenyl)methyl]-3-ethyl-1H- Salt of imidazolium with 1,1,1-trifluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonamide; 1-(3-aminopropyl)-3-[(4-vinyl) phenyl)methyl]-1H-imidazolium chloride; 1-butyl-3-[(4-vinylphenyl)methyl]-1H-imidazolium chloride; and/or b2) at least one compound selected from the group consisting of: 1-methyl-3-hexyl-1H-imidazolium 4-vinylbenzenesulfonate; 1-dodecyl-3-vinyl-1H-imidazole Onium 4-vinylbenzenesulfonate; 1-Methyl-3-propyl-1H-imidazolium 4-vinylbenzenesulfonate; and, 3-ethyl-1-methyl-1H-imidazolium 4 -(1-methylvinyl)benzenesulfonate. The adhesive composition of any one of claims 1 to 5, wherein part b) comprises at least one compound selected from the group consisting of: 3-methyl-1-hexyl-1H-imidazolium 4-vinylbenzene sulfonate; 3-vinyl-1-ethyl-1H-imidazolium 1,1,1-trifluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonamide; and 3-methyl -1-Butyl-1H-imidazolium 1,1,1-trifluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonamide. The adhesive composition of any one of claims 1 to 8, wherein part c) comprises at least one azo radical initiator selected from the group consisting of: azonitriles; azo esters; azoamides; Azoamidines; Azoimidazolines; and Macromolecular Azo Initiators. The adhesive composition of any one of claims 1 to 9, wherein the composition comprises d) a solubilizer in an amount of up to 10 wt.%, based on the weight of the composition, and the solubilizer is selected from the group consisting of Groups consisting of: polyoxyalkylene glycols; polysiloxane surfactants; polyols; and sugars. The adhesive composition of any one of claims 1 to 10, wherein the composition comprises conductive particles in an amount of up to 10 wt.%, based on the weight of the composition. The adhesive composition of claim 11, wherein the conductive particles are selected from the group consisting of silver, carbon black, and mixtures thereof. A bonding structure comprising a first material layer having a conductive surface; and, a second material layer having a conductive surface; wherein the curable and electrochemically debonded adhesive composition according to any one of claims 1 to 12 is disposed between the first material layer and the second material layer. A method of debonding the bonded structure as claimed in claim 13, the method comprising the steps of: 1) applying a voltage to the two surfaces to form an anode interface and a cathode interface; and 2) Debonding the surfaces. The method of claim 14, wherein the voltage applied in step 1 is 0.5 to 200 V and it is preferably applied for 1 second to 30 minutes.

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