Electrically debondable adhesive articles, methods of making bonded articles, and methods of debonding bonded articles

Abstract

A pressure sensitive adhesive article includes an electrically conductive composite layer having a first major surface and a second major surface. The electrically conductive composite includes an electrically conductive filler dispersed in a polymeric matrix. The pressure sensitive adhesive article further includes a first pressure sensitive adhesive layer disposed on the first major surface of the electrically conductive composite layer and a second pressure sensitive adhesive layer disposed on the second major surface of the electrically conductive composite layer. The second pressure sensitive adhesive comprises a polymerized ionic liquid. A method of making a bonded article includes bonding a pressure sensitive adhesive article to an electrically conductive substrate. A method of debonding a bonded article includes applying an electrical potential between the electrically conductive substrate and a portion of the electrically conductive composite and subsequently separating the electrically conductive substrate and the electrically non-conductive substrate.

Description

PA104841W002ELECTRICALLY DEBONDABLE ADHESIVE ARTICLES, METHODS OF MAKING BONDED ARTICLES, AND METHODS OF DEBONDING BONDED ARTICLESField

[0001] The present disclosure generally relates to the field of electrically debondable adhesives.Background

[0002] New adhesives are needed for use in the preparation of electronic devices and in various industrial applications. For example, in electronic devices, particularly mobile electronic devices (e.g., hand-held, or wearable electronic devices), various adhesives such as pressure sensitive adhesives are used to bond the cover glass (or lens) to the underlying display module, bond the touch sensor to the cover glass and display, or bond the lower components of the display to the housing. The selected adhesive typically should have sufficiently high adhesive strength to properly maintain good adhesion to those components, not only when the mobile electronic devices are operating under normal conditions, but also when they are subjected to traumatic forces (e.g., when impacted and / or dropped onto a hard surface).

[0003] Further, new adhesives are needed for electronic devices that can perform well during the lifetime of the devices but that can be removed (e.g., debonded) from the electronic components after the useful lifetime of the device or to repair the device to extend its useful lifetime. The removal of the adhesives is preferably clean so that the electronic components can be reused or recycled, or so that the electronic device can be repaired. Additionally, debonding enables reworking of mistakes made during manufacturing before a device is fully assembled using the adhesives.Brief Description of Drawings

[0004] FIG. 1 is a schematic cross-sectional view of an exemplary pressure sensitive adhesive article, according to some embodiments of the present disclosure.

[0005] FIG. 2 is a schematic cross-sectional view of an exemplary pressure sensitive adhesive article including an electrical lead, according to some embodiments of the present disclosure.

[0006] FIG. 3 is a schematic cross-sectional view of another exemplary pressure sensitive adhesive article including an electrical lead, according to some embodiments of the present disclosure.

[0007] FIG. 4 is a schematic cross-sectional view of an exemplary pressure sensitive adhesive article including a discontinuity, according to some embodiments of the present disclosure.

[0008] FIG. 5 is a schematic cross-sectional view of another exemplary pressure sensitive adhesive article including a discontinuity, according to some embodiments of the present disclosure.

[0009] FIG. 6 is a schematic top view of an exemplary pressure sensitive adhesive article including discontinuities, according to some embodiments of the present disclosure.

[0010] FIG. 7 is a schematic cross-sectional view of an exemplary pressure sensitive adhesive article including a discontinuity and an electrical lead, according to some embodiments of the present disclosure.

[0011] FIG. 8 is a schematic cross-sectional view of an exemplary electrically debondable bonded article, according to some embodiments of the present disclosure.

[0012] FIG. 9 is a schematic cross-sectional view of another exemplary electrically debondable bonded article, according to some embodiments of the present disclosure.

[0013] FIG. 10 is a schematic cross-sectional view of a further exemplary electrically debondable bonded article, according to some embodiments of the present disclosure.

[0014] Repeated use of reference characters in the specification and drawings is intended to represent the same or analogous features or elements of the disclosure. It should be understood that numerous other modifications and embodiments can be devised by those skilled in the art, which fall within the scope and spirit of the principles of the disclosure. The figures may not be drawn to scale.Summary

[0015] Electrically debondable adhesives conventionally require electrically conductive substrates on either side of the adhesive bond to act as electrodes during the electrification and to initiate debonding. However, it may be desirable to be able to use electrically debondable adhesives on a wider variety of substrates. One option to expand the utility of this technology is to provide one or two of the electrically conductive components to serve as electrodes for debonding as conductive carriers embedded into the adhesive article.

[0016] In a first aspect, a pressure sensitive adhesive article is provided. The pressure sensitive adhesive article comprises an electrically conductive composite layer having a first major surface and a second major surface, wherein the electrically conductive composite comprises an electrically conductive filler dispersed in a polymeric matrix. The pressure sensitive adhesive article further comprises a first pressure sensitive adhesive layer disposed on the first major surface of the electrically conductive composite layer: and a second pressure sensitive adhesive layer disposed on the second major surface of the electrically conductive composite layer. The second pressure sensitive adhesive comprises a polymerized ionic liquid.

[0017] In a second aspect, a method of making a bonded article is provided. The method comprises bonding a pressure sensitive adhesive article to an electrically conductive substrate. The pressure sensitive adhesive article comprises an electrically conductive composite layer having a first major surface and a second major surface, wherein the electrically conductive composite comprises an electrically conductive filler dispersed in a polymeric matrix. The pressure sensitive adhesive article further comprises a first pressure sensitive adhesive layer disposed on the first major surface of the electrically conductive composite layer; and a second pressure sensitive adhesive layer disposed on the second major surface of the electrically conductive composite layer. The second pressure sensitive adhesive comprises a polymerized ionic liquid. The second pressure sensitive adhesive layer is bonded to the electrically conductive substrate. Optionally, the method further comprises bonding the first pressure sensitive adhesive layer to an electrically non-conductive substrate.

[0018] In a third aspect, a method of debonding a bonded article is provided. The method comprises applying an electrical potential between the electrically conductive substrate and a portion of the electrically conductive composite and subsequently separating the electrically conductive substrate and the electrically non-conductive substrate.

[0019] In a fourth aspect, another pressure sensitive adhesive article is provided. The pressure sensitive adhesive article comprises an electrically conductive first pressure sensitive adhesive layer and a second pressure sensitive adhesive layer disposed adjacent to the electrically conductive first pressure sensitive adhesive layer. The second pressure sensitive adhesive comprises a polymerized ionic liquid.

[0020] The above summary is not intended to describe each embodiment. The details of one or more embodiments are also set forth in the description below. Other features, objects, and advantages will be apparent from the description and from the claims.Detailed Description

[0021] The terms “a”, “an”, “the”, “at least one”, and “one or more” are used interchangeably.

[0022] The term “and / or” means one or both such as in the expression A and / or B refers to A alone, B alone, or to both A and B.

[0023] The term “essentially free of’ means 10 parts per hundred parts resin (phr) or less, 7 phr. 5 phr, 3 phr, 2 phr, or 1 phr or less.

[0024] The term “alkyl” refers to a monovalent radical of an alkane. Suitable alkyl groups can have up to 50 carbon atoms, up to 40 carbon atoms, up to 30 carbon atoms, up to 20 carbon atoms, up to 16 carbon atoms, up to 12 carbon atoms, up to 10 carbon atoms, up to 8 carbon atoms, up to 6 carbon atoms, up to 4 carbon atoms, or up to 3 carbon atoms. The alkyl groups can be linear, branched, cyclic, or a combination thereof. Linear alkyl groups often have 1 to 30 carbon atoms, 1 to 20 carbon atoms, 1 to 10 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms. Branched alkyl groups often have 3 to 50 carbon atoms, 3 to 40 carbon atoms, 4 to 20 carbon atoms, 3 to 10 carbon atoms, or 3 to 6 carbon atoms. Cyclic alkyl groups often have 3 to 50 carbon atoms. 5 to 40 carbon atoms, 6 to 20 carbon atoms. 5 to 10 carbon atoms, or 6 to 10 carbon atoms.

[0025] The term “alkylene” refers to a divalent group that is a radical of an alkane. The alkylene can be straight-chained, branched, cyclic, or combinations thereof. The alkylene typically has 1 to 20 carbon atoms. In some embodiments, the alkylene contains 4 to 14 carbon atoms, 1 to 10 carbon atoms, 1 to 8 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms. The radical centers of the alkylene can be on the same carbon atom (i.e.. an alkylidene) or on different carbon atoms. In certain embodiments, the alkylene can be substituted with an OH group.

[0026] The term “hydroxyl group” means a monovalent group of formula -OH.

[0027] The term “aryl” refers to a monovalent group that is radical of an arene, which is a carbocyclic, aromatic compound. The aryl can have one to five rings that are connected to or fused to the aromatic ring. The other ring structures can be aromatic, non-aromatic. or combinations thereof. Examples of arylgroups include, but are not limited to. phenyl, biphenyl, terphenyl, naphthyl, acenaphthyl, anthraquinonyl, phenanthryl, anthracenyl, pyrenyl, perylenyl, and fluorenyl.

[0028] The term “aralkyl” refers to a monovalent group of formula -R-Ar where R is an alkylene and Ar is an aryl group. That is, the aralkyl is an alkyl substituted with an aryl.

[0029] The term “aralkylene” refers to a divalent group of formula -R-Ara- where R is an alkylene and Arais an arylene (i.e.. an alkylene is bonded to an arylene).

[0030] The term “arylene” refers to a divalent group that is carbocyclic and aromatic. The group has one to five rings that are connected, fused, or combinations thereof. The other rings can be aromatic, non-aromatic, or combinations thereof. In some embodiments, the arylene group has up to 5 rings, up to 4 rings, up to 3 rings, up to 2 rings, or one aromatic ring. For example, the ary lene group can be phenylene. The term “alkarylene” refers to a divalent group that is an ary lene group substituted with an alkyl group or an arylene group attached to an alkylene group. Unless otherwise indicated, the alkary lene group ty pically has from 1 to 20 carbon atoms, 4 to 14 carbon atoms, 1 to 10 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms. Unless otherwise indicated, for both groups, the alkyl or alkylene portion typically has from 1 to 20 carbon atoms, 1 to 10 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms. Unless otherwise indicated, for both groups, the aryl or arylene portion typically has from 6 to 20 carbon atoms, 6 to 18 carbon atoms, 6 to 16 carbon atoms, 6 to 12 carbon atoms, or 6 to 10 carbon atoms. In certain embodiments, the arylene group or the alkarylene group has 4 to 14 carbon atoms.

[0031] The term “(meth)acrylate” means acrylate or methacrylate.

[0032] The term “(meth)acryT means CH2=CR-(C=O)-D. where D is oxygen, sulfur, or NR wherein R is H or a lower alkyl of 1 to 4 carbon atoms.

[0033] The term “(meth)acryloyl” refers to a group of formula CH2=CR-(C=O)- where R is hydrogen (for an acryloyl group) or methyl (for a methacryloyl group).

[0034] As used herein, the term “macromer” refers to a monomer having a polymeric group. A macromer is a subset of the term “monomer”.

[0035] The term “monomeric unit” refers to the reaction product of a polymerizable component (i.e., a monomer (including a macromer)) within the (meth)acrylate copolymer. As an example, the monomeric unit of acrylic acidH HH-> C=CH *— c-c— *[=0 H |=OOH isOHwhere the asterisks (*) indicate the attachment site to another group such as another monomeric unit or terminal group in the (meth)acrylate copolymer.

[0036] The term “poly (ethylene oxide) group” refers to a group that contains at least 3 ethylene oxide (-(C2H4O)-) groups and the term “poly (propylene oxide) group” refers to a group that contains at least 3 propylene oxide (-(Cdgroups. The term “poly (butylene oxide) group” refers to a group that contains at least 3 butylene oxide (-(C4H8O)-) groups.

[0037] The term “poly (ethylene oxide-co-propylene oxide) group” contains at least 3 monomer units of some combination of ethylene oxide groups and propylene oxide groups. The polyethylene oxide-co-propylene oxide) group is a copolymeric group.

[0038] The term “polyester” refers to repeating difunctional polymer wherein the repeat units are joined by ester linkages. Ester groups have the general formula -R — C(O) — OR’. The term “poly ether” refers to repeating difunctional alkoxy radicals having the general formula -O-R-. Preferred R and R’ groups have the general formula -CnHzn- and include, for example, methylene, ethylene, propylene (including n-propylene and i-propylene) and butylene, or a combination thereof. Combinations of R and R’ groups may be provided, for example, as random or block type copolymers.

[0039] The term “ambient temperature” refers to a temperature in the range of 20 degrees Celsius to 25 degrees Celsius, inclusive.

[0040] The terms “cure” and “curable” refer to joining polymer chains together by covalent chemical bonds, usually via crosslinking molecules or groups, to form a network poly mer. Therefore, in this disclosure the terms “cured” and “crosslinked” may be used interchangeably. A cured or crosslinked polymer is generally characterized by insolubility’, but may be swellable in the presence of an appropriate solvent.

[0041] The term “polymerizable component” refers to any material (e.g., monomers, crosslinkers, oligomers, macromers, prepolymers, polymers, etc.) that participates in a curing or crosslinking reaction in forming a polymer and / or crosslinked polymer.

[0042] The term “resin” with respect to “parts per hundred parts resin” refers to 100 parts of the total polymerizable components.

[0043] The term “backbone” refers to the main continuous chain of a polymer.

[0044] The term "substantially”, unless otherwise specifically defined, means to a high degree of approximation (e.g., within + / - 10% for quantifiable properties) but again without requiring absolute precision or a perfect match. Terms such as same, equal, uniform, constant, strictly, and the like, are understood to be within the usual tolerances or measuring error applicable to the specific circumstance rather than requiring absolute precision or a perfect match.

[0045] By definition, the total weight percentages of all ingredients in a composition equals 100 weight percent.

[0046] The term “film” or “layer” refers to a single stratum within a multilayer film or article.

[0047] The term “substrate” encompasses films, layers, and articles.

[0048] The term “perimeter” refers to a continuous line forming the exterior boundary of an object, e.g., a layer.

[0049] As used herein, “thickness” refers to the smallest dimension of a film or layer, e.g.. in a z-axis while a major surface of the film or layer is in the x- and y-axes. Thickness may be determined using a micrometer gauge or doing a microscopic analysis of a cross-sectional sample of a layer or an article.

[0050] Electronics bonding customers desire the ability to debond pressure sensitive adhesives (“PSAs”) by applying an electrical current to the substrates in contact with the PSA. Applying a voltage to thesubstrates in contact with the adhesive should significantly lower the adhesion force and result in clean separation (i.e., no cohesive failure) from the substrates such that they can be recovered rapidly.

[0051] Debond-on-demand is an increasingly desirable feature for adhesives. Electro-debonding can decrease adhesion by up to 99% after applying low voltages for short times (e.g. < 50 V for < 5 minutes), enabling fast and easy disassembly of devices. Recent work has utilized double coated tapes (DCTs) with debondable adhesive layers where the film carrier (e.g.. PET) has an electrically conductive coating (e g., metal) to act as an electrode to complete the electrical circuit necessary for the electrically debondable adhesive. However, DCTs with PET carriers tend to have low performance in impact resistance tests due to the high stiffness of the PET layer. Likewise, they are often coated with conductive metal layers which can detach from the PET layers, making them fail in impact or during extended aging tests. It would be desirable to develop a thinner, lower modulus conductive layer that acts as an electrode, and without the need for the high modulus PET layer. Since the electrode is thinner and has a lower modulus / less barrier properties than PET, such an electrode could be more prone to migration of a loose ionic liquid from the PSA layer to other layers or interfaces, resulting in premature failure during ageing / conditioning.Therefore, debondable PSA layers with non-migratable ionic liquids (i.e., polymerized ionic liquids) would be desirable in this multi-layer tape construction.

[0052] Pressure Sensitive Adhesive Articles

[0053] In a first aspect, a pressure sensitive adhesive article is provided. The pressure sensitive adhesive article comprises:

[0054] an electrically conductive composite layer having a first major surface and a second major surface, wherein the electrically conductive composite comprises an electrically conductive filler dispersed in a polymeric matrix;

[0055] a first pressure sensitive adhesive layer disposed on the first major surface of the electrically conductive composite layer; and

[0056] a second pressure sensitive adhesive layer disposed on the second major surface of the electrically conductive composite layer, wherein the second pressure sensitive adhesive comprises a polymerized ionic liquid.

[0057] In certain embodiments, adhesive compositions disclosed herein comprising a polymerized ionic liquid can undergo electrically induced adhesive debonding, wherein the adhesive composition can be debonded on demand with the application of a voltage across certain portions of the pressure sensitive adhesive article. Although not wanting to be limited by theory, it is believed that when a voltage is applied to the adhesive composition comprising an ionic liquid, electrolysis of the ionic liquid occurs, wherein the cations migrate toward the cathode side and the anions migrate toward the anode side, thereby weakening the adhesive interface.

[0058] In at least certain embodiments according to the present disclosure, an adhesive composition exhibits a decrease in peel strength of at least 50% following subjection to 50 volts (V) for one minute or following subjection to 10 V for 5 seconds, 10 seconds, 20 seconds. 30 seconds, 45 seconds, or 60seconds, as determined by the Peel Adhesion Test Method. In some cases, an adhesive composition exhibits a decrease in peel strength of at least 55%, 60%. 65%. 70%, 75%, 80%. 85%. 90%, or at least 95%, as determined by the Peel Adhesion Test Method. The decrease in peel strength following subjection to the voltage is a measure of the extent of electro-debonding capability of an adhesive composition, with a larger decrease indicating greater debonding.

[0059] Referring to FIG. 1. a pressure sensitive adhesive article 100 comprises an electrically conductive composite layer 110 having a first major surface 112 and a second major surface 114; a first pressure sensitive adhesive layer 120 disposed on the first major surface 112 of the electrically conductive composite layer 110; and a second pressure sensitive adhesive layer 130 disposed on the second major surface 114 of the electrically conductive composite layer 110.

[0060] The thickness of each of the first pressure sensitive adhesive layer and the second pressure sensitive adhesive layer may vary, such each independently having as an average thickness of 10 micrometers or greater, 20 micrometers, 30, 50, 75, 100, 125. 150, 175, 200, 225, 250, 275, 300, 325, 350, 375, 400, 425, 450, 475, 500, 525, 550, 575, 600, 625, 650, 675, 700, 725, 750, 775, 800, 825, 850, 875, 900, 925, 950, 975, 1000, 1025, 1050, 1075, 1100, 1125, 1150, 1175, 1200, 1225, 1250, 1275, or 1300 micrometers or greater; and 1500 micrometers or less, 1475, 1450, 1425, 1400, 1375, 1350, 1325, 1300, 1275, 1250, 1225, 1200, 1175, 1150, 1125, 1100, 1075, 1050, 1025, 1000, 975, 950, 925, 900, 875, 850. 825, 800, 775, 750, 725, 700, 675, 650, 625, 600, 575, 550, 525, 500, 475, 450, 425, 400, 375. 350, 325. 300, 275, 250, 225, 200, 175, 150, 125. or 100 micrometers or less. The average thickness of the first pressure sensitive adhesive layer and the second pressure sensitive adhesive layer may be either the same or different from each other. In select embodiments, at least one of the first pressure sensitive adhesive layer or the second pressure sensitive adhesive layer has an average thickness of 500 micrometers to 1500 micrometers. Coating techniques known in the art for applying a layer of a pressure sensitive adhesive may be used such as spray coating, flood coating, knife coating, Meyer bar coating, gravure coating, and double roll coating.

[0061] An average thickness of the electrically conductive composite layer may vary based on the composition of the layer, typically ranging from 1 micrometer to 100 micrometers, such as 1 micrometer or greater, 5. 10, 15, 20. 25. 30, 35, 40. 45. 50, 55, 60, 65. or 70 micrometers or greater; and 100 micrometers or less, 95. 90, 85, 80, 75. 70. 65, 60, 55, 50. 45, 40, 35, 30. 25. or 20 micrometers or less.

[0062] In some cases, an electrical lead is provided as part of the pressure sensitive adhesive article. An electrical lead may be used as part of an electrical circuit for use in applying an electrical potential between certain portions of an article to impart electrical debonding of layers of the article. In some embodiments, the electrical lead comprises at least one of a wire, a conductive adhesive, or a conductive film.

[0063] For instance, in the embodiment depicted in FIG. 2, a pressure sensitive adhesive article 200 comprises an electrically conductive composite layer 110 having a first major surface 112 and a second major surface 114; a first pressure sensitive adhesive layer 120 disposed on the first major surface 112 of the electrically conductive composite layer 110; a second pressure sensitive adhesive layer 130 disposedon the second major surface 114 of the electrically conductive composite layer 110; and an electrical lead 170 attached to a portion of the electrically conductive composite layer 110. An electrical lead may be attached when the electrically conductive composite layer is manufactured, before it is joined to the rest of the pressure sensitive adhesive article. Alternatively, an electrical lead may be attached to a portion of the electrically conductive composite layer after preparation of the pressure sensitive adhesive article.

[0064] In the embodiment depicted in FIG. 3, a pressure sensitive adhesive article 300 comprises an electrically conductive composite layer 110 having a first major surface 112 and a second major surface 114; a first pressure sensitive adhesive layer 120 disposed on the first major surface 112 of the electrically conductive composite layer 110; a second pressure sensitive adhesive layer 130 disposed on the second major surface 114 of the electrically conductive composite layer 110; and an electrical lead 170 attached to a portion of the first pressure sensitive adhesive layer 120. In such cases, the first pressure sensitive adhesive layer 120 is electrically conductive.

[0065] In some cases, at least one of the first pressure sensitive adhesive layer or the second pressure sensitive adhesive layer has at least one discontinuity, which allows access to the electrically conductive composite layer. For instance, in the pressure sensitive adhesive article 400 depicted in FIG. 4, the discontinuity comprises an aperture 180 through the first pressure sensitive adhesive layer 120, wherein the aperture 180 is spaced apart from a perimeter 121 of die first pressure sensitive adhesive layer 120. Also shown in FIG. 4 are the electrically conductive composite layer 110 having first 112 and second 114 major surfaces and the second pressure sensitive adhesive layer 130 disposed on the second major surface 114 of the electrically conductive composite layer 110. In the pressure sensitive adhesive article 500 depicted in FIG. 5, the discontinuity comprises an aperture 180 through the second pressure sensitive adhesive layer 130, wherein the aperture 180 is spaced apart from a perimeter 131 of the second pressure sensitive adhesive layer 130. Also shown in FIG. 5 are the electrically conductive composite layer 110 having first 112 and second 114 major surfaces and the first pressure sensitive adhesive layer 120 disposed on the first major surface 112 of the electrically conductive composite layer 110.

[0066] More generally, various embodiments of discontinuities in a first pressure sensitive adhesive layer 120 are illustrated in FIG. 6. In addition to the aperture 180c, FIG. 6 illustrates two different notches 180a, 180b through the first pressure sensitive adhesive layer 120, wherein the notch interrupts the perimeter 121. The apertures and notches can have any desirable shape and may be present in a layer alone, or in combination as shown in FIG. 6. Referring to the pressure sensitive adhesive article 700 depicted in FIG. 7, in some cases, an electrical lead 170 is attached to a portion of the electrically conductive composite layer 110 exposed by the at least one discontinuity 180. The pressure sensitive adhesive article 700 of this embodiment further includes a first pressure sensitive adhesive layer 120 disposed on the first major surface 112 of the electrically conductive composite layer 110; and a second pressure sensitive adhesive layer 130 disposed on the second major surface 114 of the electrically conductive composite layer 110.

[0067] Typically, and advantageously, the at least one discontinuity is not created by an electrode, and methods of debonding a bonded article do not include penetrating a continuous adhesive layer with anelectrode or other implement to initiate the debonding after the bonded article is made. Advantageously, at least one discontinuity can be made when the pressure sensitive adhesive article is manufactured using a variety of techniques such as die cutting and laser cutting any desired shape. Kiss cutting can be useful to provide at least one discontinuity after the first or second adhesive layer is attached (e.g.. laminated) to the electrically conductive composite layer. The shape of the discontinuity can be predetermined and not dictated by the shape of the electrode or implement that would be used to penetrate the adhesive after the bonded article is made. Optionally, at least one discontinuity can be made by patterning the adhesive from a variety of manufacturing processes including flexographic printing, gravure printing, screen printing, stencil printing.

[0068] Suitable materials for each of the electrically conductive composite layer 110, the first pressure sensitive adhesive layer 120, and the second pressure sensitive adhesive layer 130 are described in detail below.

[0069] Electrically Conductive Composite Layer

[0070] As noted above, the electrically conductive composite layer comprises an electrically conductive filler dispersed in a polymeric matrix. Suitable electrically conductive fillers and poly mers are described herein.

[0071] The electrically conductive filler is not particularly limited. Broadly, the electrically conductive filler may comprise at least one of a metal, mixed metal, alloy, metal oxide, composite metal oxide, metal coated glass, an organometallic complex, graphene, graphite, carbon black, or other carbon-based filler. In certain embodiments, the electrically conductive filler comprises a carbon-based filler, such as carbon nanotubes, carbon fibers, carbon nanofibers, graphene, graphite, or conductive carbon black.

[0072] Exemplary conductive particles include for instance and without limitation, the carbon-based fillers listed above (e.g., conductive carbon black) or metal particles of aluminum, silver, copper, nickel, gold, tin, zinc, chromium, cobalt, platinum, palladium, iron, tungsten, molybdenum, alloys thereof, solder, or the like, a phthalocyanine pigment, anthraquinone, indigoid, quinacridone. or a dioxazine pigment, or particles prepared with a surface covering or coating of a conductive coating of a metal, alloy, or the like, can be used. It also is possible to use non-conductive particles of a polymer such as polyethylene, polystyrene, phenol resin, epoxy resin, acryl resin or benzoguanamine resin, or glass beads, silica, graphite or a ceramic, with conductive surface coatings (e.g., coating(s) of metal(s), alloy(s), or the like), e.g., nickel coated graphite particles.

[0073] In some cases, a preferred electrically conductive filler is conductive carbon black. “Conductive carbon black” is a term known in the art to be distinct from pigment carbon black. Conductive grades of carbon black include those from Imerys Graphite & Carbon, Bodio, Switzerland under the trade designation “Super P Conductive Carbon Black”, from Columbian Chemical Company, Atlanta, GA under the trade designation “CONDUCTEX 975 ULTRA”, from Degussa, Frankfurt, Republic of Germany under the trade designation “PRINTEX XE-2”, and from Cabot Corporation, Boston, MA, under the trade designation “BLACK PEARLS 2000”. Conductive carbon black generally has smaller particles sizes, more structure (e.g., high void volume), more porosity, and less surface functionality thanpigment carbon black. Conductive carbon black can comprise 99% amorphous carbon. Typically, conductive carbon black has an oil absorption number (OAN) of at least 170 mL / 100 g, measured using techniques known in the art.

[0074] Useful electrically conductive particles are available in a variety of shapes (e.g., spherical, ellipsoidal, cylindrical, flakes, needle, whisker, platelet, agglomerate, crystal, acicular). The particle may have a slightly rough or spiked surface. The shape of the electrically conductive particles is not particularly limited but a nearly spherical shape is preferred in some embodiments. The choice of shape is typically dependent upon the rheology of the selected resin components and ease of processing of the final resin / particle mix. Combinations of particle shapes, sizes, and hardness may be used in the disclosed adhesive compositions.

[0075] The electrically conductive filler can have any desired particle size, including in a range from 10 nanometers to 10 micrometers.

[0076] Electrically conductive particles may be employed in an amount of 5 wt.% to 50 wt.%, based on a total weight of the electrically conductive composite layer such as 5 wt.% or greater, 10 wt.%, 15 wt.%, 20 wt.%, 25 wt.%, 30 wt.%, or 35 wt.% or greater; and 50 wt.% or less, 45 wt.%, 40 wt.%, 35 wt.%, 30 wt.%, 25 wt.%, 20 wt.%, or 15 wt.% or less.

[0077] The polymer of the polymeric matrix is not particularly limited. For instance, the polymeric matrix of the electrically conductive composite layer optionally comprises a poly(meth)acrylate, a polyurethane, a polyethylene, a polypropylene, a polyvinyl chloride, chlorinated polyolefin, a polystyrene, a polyvinyl butyral, a polyacrylonitrile, a polyimide, polyvinyl acetate, a polyester, a polyamide, polycarbonate, an alkyd resin, an epoxy resin, a phenolic resin, a natural rubber, a synthetic rubber, a silicone rubber, or combinations thereof.

[0078] Exemplary suitable polymers include for instance and without limitation, a polymer comprising at least one of a polyurethane (e.g., a polyurethane as described in U. S. Pat. No. 10,301,418 (Lu et al.)), a polyacrylate, a polyamide, or a rubber. Polyacrylates and / or rubbers described in U. S. Pat. Nos.10,640,656 (Moren et al.), 5,602.202 (Groves), and 5,677,376 (Groves) may be useful polymers in a primer composition. Polyamides useful in conductive primer compositions include dimer-acid based polyamides. Dimer acids can be used alone or in combination with other diacids. Suitable acids for making polyamides include any those described in paragraphs

[0038] to

[0041] of U. S. Pat. No.2022 / 0347982 (Perez et al.), and suitable polyamines for making polyamides include any those described in paragraphs

[0042] to

[0043] of U. S. Pat. No. 2022 / 0347982 (Perez et al.). Further examples of useful conductive primer compositions and polyacrylates useful in conductive primer compositions include those described in co-pending PCT Publication WO 2025 / 037281 (Amos et al.). Conductive primers may also include solvent.

[0079] A polymer matrix containing electrically conductive filler can be in the form of a film, nonwoven, or foam, for example. The electrically conductive filler may be blended in with the polymer and optionally at least one solvent, dispersant, or other processing aid, then formed into a layer. For example, conductive compositions can be applied using the methods of brushing (e.g., using a soft-bristlebrush), spraying (e.g., using a spray gun or aerosol can), jetting (e.g., using a jetting gun or nozzle), printing (e.g., screen printing or flexo printing), or dipping. If present, solvent can be removed composition by allowing it to dry for 10, 20, or 30 minutes or longer in an ambient environment. An electrically conductive composite layer thus formed may have a thickness of not more than 25, 20, 15, 20, or 5 micrometers. In some embodiments, the electrically conductive layer (e.g., after removing solvent, if present) has a resistivity of not more than 1, 0.5, 0.25, 0.1, or 0.05 megaohm centimeter. Some specific suitable methods of forming electrically conductive composite layers are described in the Examples below.

[0080] In some embodiments, the conductive composite layer advantageously exhibits a Young's modulus of at least 0.1 megaPascals (MPa), 1, 10, 100, 200, or 300 MPa, as determined by Tensile DMA or uniaxial tensile testing. Numerous compositional factors will affect the Young’s modulus, including for instance, modulus of the polymer used for the polymeric matrix, the specific filler employed, the filler loading, and the filler particle aspect ratio.

[0081] Typically, the conductive composite layer is one continuous layer of electrically conductive filler dispersed in the polymeric matrix (e.g., electrically conductive filler being present throughout the bulk thickness of the conductive composite layer). This is in contrast to a conductive coating present on a non-conductive substrate.

[0082] First Pressure Sensitive Adhesive Layer

[0083] The first pressure sensitive adhesive layer comprises a layer of a pressure sensitive adhesive. Pressure sensitive adhesives (PSAs) are well known to one of ordinary skill in the art to possess certain properties including the following: (1) aggressive and permanent tack, (2) adherence with no more than finger pressure, (3) sufficient ability to hold onto an adherend, and (4) sufficient cohesive strength to be removable from an adherend. PSAs commonly provides overlap shear strength not exceeding 1, or 2, or at -most 4 megaPascals (MPa) when bonding substrates at room temperature. The PSA is not particularly limited. Examples of suitable polymers for the first PSA layer include acrylic polymers, rubber-based polymers, vinyl-alkyl-ether-based polymers, silicone-based polymers, polyester-based polymers, polyamide-based polymers, and urethane-based polymers. In certain embodiments, the first pressure sensitive adhesive layer comprises a different polymer than the second pressure sensitive adhesive layer. In other embodiments, the first pressure sensitive adhesive layer comprises the same polymer as the second pressure sensitive adhesive layer.

[0084] In some embodiments, the first pressure sensitive adhesive layer also includes a polymerized ionic liquid, such that the first pressure sensitive adhesive layer is also an electrically debondable PSA. Alternatively, in some embodiments, the first pressure sensitive adhesive layer is essentially free of an ionic liquid and / or essentially free of a polymerized ionic liquid. In such embodiments, the first pressure sensitive adhesive is not electrically debondable. Is it to be understood that low amounts of ionic liquid (e.g., less than 5 phr or less than 3 phr) and / or polymerized ionic liquid (e.g., less than 10 phr or less than 5 phr) can provide antistatic properties and / or improve mechanical integrity to the PSA layer with minimal effectiveness for electrical debonding.

[0085] Second Pressure Sensitive Adhesive Layer

[0086] As noted above, the second pressure sensitive adhesive comprises a polymerized ionic liquid. It is to be understood that the term “polymerized ionic liquid” refers to a cured polymerizable ionic liquid. The curing results in formation of a covalent bond between the polymerized ionic liquid and a polymer of the pressure sensitive adhesive. Such a chemical bond tethers the polymerized ionic liquid to the polymer of the pressure sensitive adhesive, minimizing the ability of the ionic liquid to migrate within the pressure sensitive adhesive article, e.g., to a surface of the second pressure sensitive adhesive or even migrating out of the second pressure sensitive adhesive. It is not expected that a significant amount of the polymerizable ionic liquid homopolymerizes instead of co-polymerizing with the polymer of the pressure sensitive adhesive.

[0087] In certain embodiments, the second pressure sensitive adhesive layer comprises at least one polymer selected from the group consisting of a (meth)acrylic polymer, a rubber-based polymer, a vinyl alkyl ether-based polymer, a silicone-based polymer, a polyester-based polymer, a polyamide-based polymer, and a urethane-based polymer. Additionally, the second pressure sensitive adhesive layer comprises an ionic liquid covalently attached to at least one polymer of the second pressure sensitive adhesive. Suitable polymerizable ionic liquids are described in detail below.

[0088] To prepare the second pressure sensitive adhesive layer, typically a polymerizable composition is formed including at least one polymerizable ionic liquid and an adhesive precursor comprising at least one monomer, macromer, or polymer: and curing the polymerizable composition to covalently bond the polymerizable ionic liquid to the at least one polymer of the second pressure sensitive adhesive. Curing may be effected by various methods known in the adhesive art, such as photoinitiation, thermal initiation, and / or e-beam curing. Some suitable methods of forming second pressure sensitive adhesive layers are described in detail in the Examples below.

[0089] Ionic Liquid

[0090] In some cases, a suitable ionic liquid is a polymerizable component, whereas in other cases an ionic liquid is not a polymerizable component, depending on the specific ionic liquid.

[0091] The presence of an ionic liquid may be useful in easing the peeling (or peel-ability) of the adhesive when reworking or recycling an article. An ionic liquid is a unique salt, which is in a liquid state at about 100 °C or less, has negligible vapor pressure, and high thermal stability. The ionic liquid is composed of a cation and an anion and has a melting point of no more than 100 °C, (i.e., being a liquid at about 100 °C or less), about 95 °C or less, or even about 80 °C or less. Certain ionic liquids exist in a molten state even at ambient temperature since their melting points are less than room temperature, and therefore they are sometimes referred to as ambient temperature molten salts. The cation and / or anion of the ionic liquid are relatively sterically bulky, and typically one and / or both of these ions are an organic ion. Further, the cation and / or anion of a polymerized ionic liquid is non-protonated. The ionic liquid can be synthesized by known methods, for example, by a process such as anion exchange or metathesis process, or via an acid-base or neutralization process.

[0092] The cation of the ionic liquid of the present disclosure may be a nitrogen-containing cation (e.g., an ammonium ion), a phosphonium ion, a sulfonium ion. an imidazolium ion. a pyridinium ion, an iodonium ion, or the like, including various delocalized heteroaromatic cations, but is not limited thereto. The nitrogen-containing cation includes ions such as. alkylammonium, imidazolium. pyridinium, pyrrolidinium, pyrrolinium, pyrazinium, pyrimidinium. triazonium, triazinium. quinolinium, isoquinolinium, indolinium. quinoxalinium, piperidinium, oxazolinium, thiazolinium, morpholinium, or piperazinium. Examples of the phosphonium ion include tetraalkylphosphonium, arylphosphonium, or alkylarylphosphonium. Examples of the sulfonium ion include alkylsulfonium, arylsulfonium, thiophenium. or tetrahydro thiophenium. The alkyl group directly bonded to a nitrogen atom, a phosphorus atom, or a sulfur atom may be a linear, branched or cyclic alkyl group having a carbon number of at least 1, 2, or even 4 and not more than 8, 10, 12. 15, or even 20. The alkyl group may optionally contain heteroatoms such as O, N, and / or S in the chain or at the end of the chain (e.g.. a terminal -OH group). The ary l group directly bonded to a nitrogen atom, a phosphorus atom, or a sulfur atom may be a monocyclic or condensed cyclic ary l group having at least 5, 6, or even 8 carbon atoms and not more than 12, 15, or even 20 carbon atoms. An arbitrary site in the structure constituting such a cation may be further substituted by an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an aryl group, an aralkyl group, an arylalkyl group, an alkoxy group, an aryloxy group, a hydroxyl group, a carbonyl group, a carboxyl group, an ester group, a urethane group, an acyl group, an amino group, a dialkylamino group, an amide group, an imino group, an imide group, a nitro group, a nitrile group, a sulfide group, a sulfoxide group, a sulfone group, a halogen atom or the like. A heteroatom such as oxygen atom, nitrogen atom, sulfur atom, and / or silicon atom may be contained in the main chain or ring of the structure constituting the cation.

[0093] Specific examples of the cation include N-ethyl-N'-methylimidazolium, N-methyl-N'-buty limidazolium, N -methy 1-N -propy Ipiperidinium, N, N, N-trimethyl-N -propylammonium, N -methyl-N, N, N-tripropylammonium, N. N. N-trimethyl-N-butylammonium, N, N, N-trimethyl-N-methoxyethylammonium, N-methyl-N, N. N-tris(methoxyethyl)ammonium, N. N-dimethyl-N-butyl-N-methoxyethylammonium, N, N-dimethyl-N, N-dibutylammonium, N-methyl-N, N-dibutyl-N-methoxyethylammonium. N-methyl-N, N, N-tributylammonium. N, N, N-trimethy 1-N -hexylammonium. N. N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium. 1-propyl-tetrahydrothiophenium. 1-butyl-tetrahydrothiophenium. 1-penty 1-tetrahydrothiophenium, 1 -hexyl-tetrahydrothiophenium. glycidyltrimethylammonium, N-ethylacryloyl-N. N, N-trimethylammonium, N-ethyl-N-methylmorphonium, N. N. N-trioctylammonium, N-methyl-N, N. N-trioctylammonium, N, N-dimethyl-N-octyl-N-(2-hydroxyethyl)ammonium, triethylsulfonium, or mixtures thereof.

[0094] In select embodiments, the second pressure sensitive adhesive comprises a polymerized ionic liquid whose ionic liquid precursor comprises an ionic liquid and the polymerizable functional group of the cation of the ionic liquid comprises at least one of a (meth)acrylate group, a (meth)acrylamide group, a vinyl group, an alcohol group, an epoxy group, a primary or secondary amino group, or a thiol group.

[0095] The anion of the ionic liquid of the present disclosure may be, for example, a sulfate (R-OSO3); a sulfonate (R-SO3 ); a carboxylate (R-CO2 ); a phosphate ((RO)2P(=O)O); a borate represented by the formula: BRf, such as tetrafluoroborate (BF4), tetraalkylborate, and tetraphenylborate; an oxalato borate, such as lithium difluoro(oxalato)borate; a phosphate represented by the formula: PR, / . such as (PFe ) and hexaalkylphosphate; an imide (R2N ); a bis(sulfonyl)imide (either symmetrical or asymmetrical, e g., a bis(fluorosulfonyl)imide, a bis(fluoroalkylsulfonyl)imide); a sulfidoimide; an imide; a methide (R3C); a nitrate ion (NO3 ); a nitrite ion (NO2 ); a dicyanamide ((CN)2N‘); a tricyanomethanide; a phosphorus-containing ion; or a halide such as iodide. In the formulas listed above, each R may be independently a hydrogen atom, a halogen atom (fluorine, chlorine, bromine, iodine), a substituted or unsubstituted alkyl, alkenyl, alkynyl, cycloalkyl, aryl, aralkyl, arylalkyl, acyl or sulfonyl group, or the like. A heteroatom such as an oxygen atom, a nitrogen atom or a sulfur atom may be contained in the main chain or ring of the group R, and a part or all of hydrogen atoms on the carbon atom of the group R may be replaced with fluorine atoms. In the case where a plurality of R's are present in the anion, these R's may be the same or different.

[0096] In other select embodiments, second pressure sensitive adhesive comprises a polymerized ionic liquid whose ionic liquid precursor comprises an ionic liquid wherein the polymerizable functional group of the anion of the ionic liquid comprises at least one of a (meth)acrylate group, a (meth)acrylamide group, a vinyl group, an alcohol group, an epoxy group, a primary or secondary amino group, or a thiol group.

[0097] Specific examples of the polymerizable anion include 3-sulphonatopropyl acry late (-O3S(CH2)3OC(O)CH=CH2), acrylamido-2-methyl-l-propanesulfonate( -O3SCH2C(CH3)2NHC(O)CH=CH2). acryloxy-succinyl-1-propanesulfonate ( -O3S(CH2)3OC(O)CH2CH2C(O)OCH2CH2OC(O)CH=CH2). and acryloxy-succinate(-OC(O)CH2CH2C(O)OCH2CH2OC(O)CH=CH2).

[0098] In some embodiments, it is advantageous to use a perfluorinated ion, such as a perfluorinated anion to achieve excellent corrosion resistance and electro-debonding. However, the use of fluorinated ions should be balanced with the environmental impact of the finished good, as some fluorinated chemicals may have restricted use due to environmental concerns. Examples of an anion containing a perfluoroalkyl group, which can be used, include a bis(perfluoroalkylsulfonyl)imide ((RfSCTfiN), a perfluoroalkylsulfonate (RfSCfi) and a tris(perfluoroalkylsulfonyl)methide ((RfSCfi^C) (wherein Rf represents a perfluoroalkyl group). The perfluoroalkyl group may comprise, for example, from at least 1, 2, 3 or even 4 to at most 8, 10, 12. 15, or even 20 carbon atoms. Specific examples of the bis(perfluoroalky Isulfony l)imide include: bis(trifluoromethanesulfonyl)imide, bis(pentafluoroethanesulfonyl)imide, bis(heptafluoropropanesulfonyl)imide. or bis(nonafluorobutanesulfonyl)imide. Specific examples of the perfluoroalkylsulfonate include: trifluoromethanesulfonate, pentafluoroethanesulfonate, heptafluoropropanesulfonate, or nonafluorobutane sulfonate. Specific examples of the tris(perfluoroalkylsulfonyl)methide include: tris(trifluoromcthancsulfonyl)mcthidc, tris(pcntafluorocthancsulfonyl)mcthidc,tris(heptafluoropropanesulfonyl)methide, or tris(nonafluorobutanesulfonyl)methide. Examples of fluorinated anions not comprising a C-F bond are hexafluorophosphate, hexafluoroantimonate, tetrafluoroborate, difluoroiodide, and bis(fluorosulfonyl)imide.

[0099] As for non-polymerizable ionic liquids composed of the above-described cation and anion, N-butyl-N'-methy limidazolium bis(trifluoromethanesulfonyl)imide, tri-ethyl sulfonium bis(trifluoromethanesulfonyl)imide, N-butyl- N'-methylimidazolium hexafluorophosphate. N-butyl- N'-methylimidazolium iodide, ethyl pyridinium bis(trifluoromethanesulfonyl)imide. trimethyl ammonium ethyl acrylate bis(trifluoromethanesulfonyl)imide, N-butyl- N'-methylimidazolium dicyanamide, N-ethyl-N'-methy limidazolium dicyanamide, and / or a tetra alkyl ammonium with hydroxy functionality with bis(trifluoromethanesulfonyl)imide counterion, available under the trade designation " FC-5000" from 3M Co., Maplewood, MN can be advantageously used as the ionic liquid, because of their excellent removability during electro-debonding due to reduced bond strength upon application of electricity..

[0100] Enough ionic liquid should be added to enable electro-debonding, while too much ionic liquid may negatively impact the physical properties of the adhesive, such as shear, peel adhesion, and / or ability to survive the random free fall test. The ty pe of ionic liquid used may impact how much can be added without negatively impacting the physical properties of the adhesive. For example, if the ionic liquid can be polymerized into (meth)aci late matrix, for example, the ionic liquid comprises at least one (or even at least two) acrylate, methacrylate, or styrene functional group or combinations thereof, more ionic liquid may be incorporated into the adhesive. It is noted that use of an ionic liquid that contains at least two functional groups may be less preferable for applications in which there is a substantial delay between polymerization and final use of the adhesive because the presence of multiple functional groups could result in disadvantageous early gelation of the adhesive.

[0101] Exemplary suitable polymerizable ionic liquids include for instance and without limitation. N, N, N-trimethyl ammonium ethyl acrylate bis(fluorosulfonyl)imide, N. N, N-trimethyl ammonium ethyl acrylate iodide, N. N. N -trimethyl ammonium ethyl acrylamide bis(fluorosulfonyl)imide, N. N, N-trimethyl ammonium ethyl acrylate bis(trifluoromethane sulfonyl)imide, N-hexyl-N, N-dimethyl ammonium ethyl acrylate bis(fluorosulfonyl)imide, N-hexyl-N, N-dimethyl-ammonium ethyl acrylamide tricyanomethanide or N. N, N-trimethyl ammonium ethyl acrylate tricyanomethanide, N-butyl-imidazolium-N’-ethyl acrylate bis(fluorosulfonyl)imide, N-butyl-imidazolium-N’-ethyl acrylate tricyanomethanide, dibutyl-sulfonium-ethyl acrylate bis(fluorosulfonyl)imide, dibutyl-phosphonium ethyl acrylate bis(fluorosulfonyl)imide, 3-sulfopropyl acrylate N-octy 1-N-methyl-imidazolium or 3-sulfopropyl acrylate N-butyl-N-methyl-imidazolium. N-vinyl-imidazolium bis(fluorosulfonyl)imide, sulfopropyl acry lamide N-butyl-N’-methyl imidazolium. sulfopropyl acrylamide N-octyl-N'-niethy I imidazolium. styrene sulfonate N-butyl-N'-methyl imidazolium, styrene sulfonate N-octyl-N'-methyl imidazolium, octyldimethyl-2-hydroxyethylammonium 3-sulphonatopropyl acrylate (C8H17N(CH3)2CH2CH2OH+ -O3S(CH2)3OC(O)CH=CH2), tributy lmethylammonium 3-sulphonatopropyl acry late ((C4H9)3N(CH3)+ -O3S(CH2)3OC(O)CH=CH2), tetrabutylphosphonium 3-sulphonatopropyl acrylate ( (C4H9)4P+ -O3S(CH2)3OC(O)CH=CH2), tetrabutylphosphonium acrylamido-2-methyl-1-propanesulfonate ((C4H9)4P+ -O3SCH2C(CH3)2NHC(O)CH=CH2), trimethylammonium ethyl acrylate 3-sulphonatopropyl acrylate ((CH3)3NCH2CH2OC(O)CH=CH2+- O3S(CH2)3OC(O)CH=CH2). trimethylammonium ethyl acrylate acrylamido-2-methyl-l -propanesulfonate ((CH3)3NCH2CH2OC(O)CH=CH2+ -O3SCH2C(CH3)2NHC(O)CH=CH2), octyldimethyl-2-hydroxyethylammonium acrylamido-2-methyl-1-propanesulfonate (C8H17N(CH3)2CH2CH2OH+ -O3SCH2C(CH3)2NHC(O)CH=CH2), tributylmethylammonium acrylamido-2-methyl-1-propanesulfonate ((C4H9)3N(CH3)+ -O3SCH2C(CH3)2NHC(O)CH=CH2), tributylmethylammonium acryloxy-succinyl-l-propanesulfonate ( (C4H9)3N(CH3)+-O3S(CH2)3OC(O)CH2CH2C(O)OCH2CH2OC(O)CH=CH2), tetrabutylphosphonium aery loxy-succiny 1-1 -propanesulfonate (Bu4P-SPAMAC, (C4Hg)4P+- O3S(CH2)3OC(O)CH2CH2C(O)OCH2CH2OC(O)CH=CH2), 1 -octyl-3-methylimidazolium (OMI) aery loxy-succiny 1-1 -propanesulfonate (OMI+-O3S(CH2)3OC(O)CH2CH2C(O)OCH2CH2OC(O)CH=CH2), l-butyl-3-methylimidazolium (BMI) aery loxy-succiny 1-1 -propanesulfonate (BMI+ -O3S(CH2)3OC(O)CH2CH2C(O)OCH2CH2OC(O)CH=CH2). And 1-octyl-3-methylimidazolium acryloxy-succinate (OMI+ -OC(O)CH2CH2C(O)OCH2CH2OC(O)CH=CH2).

[0102] A polymerizable ionic liquid that may be present in an amount of 1 wt.% or greater, based on a total weight of polymerizable components (e.g., adhesive precursor), such as 2 wt.%, 3 wt.%, 4 wt.%, 5 wt.%, 6 wt.%, 7 wt.%, 8 wt.%, 9 wt.%, 10 wt.%, 11 wt.%, 12 wt.%, 13 wt.%, 14 wt.%, 15 wt.%, 16 wt.%, 18 wt.%, or 20 wt.% or greater, based on a total weight of polymerizable components; and 50 wt.% or less, based on a total weight of polymerizable components, such as 45 wt.%, 40 wt.%. 35 wt.%, 30 wt.%, 28 wt.%, 26 wt.%, 24 wt.%, 22 wt.%, 20 wt.%, 18 wt.%, 16 wt.%, 15 wt.%, 14 wt.%, 12 wt.%, or 10 wt.% or less, based on a total weight of polymerizable components.

[0103] If the ionic liquid is not polymerizable into the adhesive, less ionic liquid should be used due to it negatively impacting the physical properties of the adhesive (such as static shear performance). In embodiments in which the ionic liquid comprises a non-polymerizable ionic liquid, the ionic liquid may be present in an amount of 2 parts per hundred parts resin (phr) or greater, 3 phr, 4 phr, 5 phr, 6 phr, 7 phr. 8 phr. 9 phr. or 10 phr or greater; and 20 phr or less. 18 phr, 16 phr, 14 phr, 12 phr, 10 phr, 8 phr, or 6 phr or less.

[0104] The choice of the ionic liquid used in the adhesive can impact electro-debonding. For example, it may be advantageous to choose ionic liquids that have a high conductivity or ionic mobility. While not being limited by theory, it is believed that increased ionic liquid mobility in the adhesive is beneficial for electro-debonding. As such, it may be beneficial for the ionic liquid to be highly soluble in the adhesive matrix (i.e., the ionic liquid does not phase separate from the adhesive matrix). High mobility and high conductivity (e.g., having sheet resistance less than IxlO3ohms per square) of the ionic liquid in the adhesive matrix could help enable electro-debonding in thicker adhesives. In some embodiments the adhesive thickness could be 10, 25, 50, 60, 70, 80, 90, 100, 150, 200, 250, 300, 400, or even up to 500 microns thick. Alternatively, or additionally, it may be advantageous to choose ionic liquids that have electrochemically unstable cations or anions. While not wanting to be limited by theory’, it is believed that more electrochemically unstable cations or anions could produce an increased electro-debondingresponse. As such, it may be beneficial to choose cations comprised of imidazolium or pyridinium derivatives over quaternary ammonium derivatives.

[0105] In one embodiment, it may be beneficial for environmental reasons to choose ionic liquids that do not contain carbon-fluorine bonds. As such, it may be beneficial to choose ionic liquids containing inorganic fluorine such as the hexafluorophosphate or tetrafluoroborate ion in lieu of organic fluorine such as bis(trifluoromethylsulfonyl)imide.

[0106] In some embodiments, a suitable polymerizable ionic liquid is of Formula I and / or of Formula II:^3 (II).

[0107] In each of Formula I and Formula II, Ri is independently H or methyl, and R2 and R3 are each independently linear or branched alkyl groups and / or ethoxy groups.

[0108] In some embodiments, a suitable polymerizable ionic liquid is of Formula III:

[0110] In some embodiments, a suitable polymerizable ionic liquid is of Formula V:

[0111] In some embodiments, a suitable polymerizable ionic liquid is of Formula VI:

[0112] Additive

[0113] Pressure sensitive adhesives according to the present disclosure optionally include at least one additive in at least one of the first pressure sensitive adhesive layer or the second pressure sensitive adhesive layer. Typically, each additive that is included may be present (independently) in an amount of 1 phr or greater, 2 phr, 3 phr, 5 phr, 7 phr, or 10 phr or greater; and 20 phr or less, 18 phr, 16 phr. 15 phr, 14 phr, 12 phr. 10 phr, or 8 phr or less.

[0114] In certain embodiments, at least one additive includes a tackifier (e.g., C5-resins, terpene phenol resins, (poly)terpenes and rosin esters, hydrogenated hydrocarbons, and non-hydrogenated hydrocarbon resins), a plasticizer, an adhesion promoter (e.g.. glycidyl propyl trimethoxy silane), a stabilization agent (e.g., calcium carbonate), a corrosion inhibitor (e.g., benzotriazole or 2-(methacryloyloxy)ethyl acetoacetate), a conducting salt (e.g., lithium bis(fluorosulfonyl)imide or sodium hexafluorophosphate), a colorant (e.g., titania or carbon black), an antioxidant, a polymer having a glass transition temperature of at least 40 degrees Celsius (e.g.. polyvinyl butyral), or a filler.

[0115] Some suitable antioxidants include hindered phenol compounds, phosphoric esters, or derivatives thereof. Exemplary antioxidants include those available from Ciba Specialty Chemicals Incorporated. Tarrytown. New York.

[0116] Some suitable ultraviolet (" UV") absorbers include benzotriazole, substituted triazine, oxazolic acid amide, benzophenone, or derivatives thereof, such as 2-(2H-Benzotriazol-2-yl)-6-(l-methyl-l-phenylethyl)-4-(l, 1, 3, 3-tetramethy Ibutyl) phenol (commercially available as TINUVIN 928 from BASF, Florham Park, New Jersey).

[0117] In certain embodiments, a filler comprises a plurality of hollow glass microspheres, a plurality of polymeric microparticles, a plurality of polymeric nanoparticles each comprising an interior region comprising a polymer having a glass transition temperature below room temperature and an outer shell comprising a polymer having a glass transition temperature of at least 50°C, an organo-phosphinate. a plurality of alumina particles, a plurality of pre-expanded hollow polymeric microspheres, a plurality of conductive particles (e.g.. nickel coated graphite or carbon black), or combinations thereof.

[0118] Suitable hollow microspheres include for instance and without limitation, hollow glass microspheres. Hollow glass microspheres can be made by techniques known in the art (see, e.g., U. S. Pat. Nos. 2,978,340 (Veatch et al.); 3,030,215 (Veatch et al.); 3,129,086 (Veatch et al.); and 3,230,064 (Veatch et al.); 3,365,315 (Beck et al.); 4,391,646 (Howell); and 4,767,726 (Marshall); and U. S. Pat. App. Pub. No. 2006 / 0122049 (Marshall et. al).

[0119] Exemplary polymeric microparticles include for instance, the polymeric microspheres described in detail in PCT Publication No. WO 2023 / 175424 (Maher et al.). Exemplary suitable polymeric nanoparticles include, for instance, the polymeric nanoparticles described in detail in PCT Publication No. WO 2023 / 228050 (Moughton et al.).

[0120] Suitable organo-phosphinate fillers include for instance and without limitation, those commercially available under the trade designations “EXOLIT OP 930”, “EXOLIT OP 935". and “EXOLIT OP 1230”. all from Clariant Ltd (Louisville, KY), which are each white, fine-grained powders of aluminum diethyl phosphinate flame retardant particles. Advantageously, the use of organo-phosphinate fillers tends to improve drop resistance of an adhesive even in the absence of other additives that have also been used to increase shear modulus.

[0121] Expanded microspheres are obtained by exposing expandable microspheres to heat. A wide range of expandable microspheres are suitable. Suitable expandable microspheres are ones with low density, high elasticity, and low moisture absorption such as those commercially available from Nouryon under the trade name “EXPANCEL” such as “EXPANCEL 920DU20”. In some embodiments, the expandable microspheres have a maximum expansion ratio of 6.4.

[0122] In a fourth aspect, another pressure sensitive adhesive article is provided. The pressure sensitive adhesive article comprises an electrically conductive first pressure sensitive adhesive layer; and a second pressure sensitive adhesive layer disposed adjacent to the electrically conductive first pressure sensitive adhesive layer, wherein the second pressure sensitive adhesive comprises a polymerized ionic liquid. Such a configuration advantageously enables electrical debonding capabilities without requiring presence of a separate electrically conductive layer. In some cases, the first pressure sensitive adhesive layer comprises an electrically conductive filler dispersed in a pressure sensitive adhesive to achieve electrical conductivity.

[0123] Referring to FIG. 10, a schematic cross-sectional view is provided of an exemplary bonded article 1000 comprising an electrically conductive first pressure sensitive adhesive layer 120; and a second pressure sensitive adhesive layer 130 disposed adjacent to the electrically conductive first pressure sensitive adhesive layer 120, wherein the second pressure sensitive adhesive comprises a polymerizedionic liquid (not shown). Also depicted is an electrically conductive substrate 140 bonded to the second pressure sensitive adhesive layer 130. FIG. 10 additionally depicts application of an electrical potential 190 that forms a circuit between the electrically conductive first pressure sensitive adhesive layer 120 and the electrically conductive substrate 140.

[0124] Any of the materials described above with respect to the first and second pressure sensitive adhesive layers and electrically conductive fillers may be employed in articles of this aspect.

[0125] Optionally, the pressure sensitive adhesive article further comprises a non-conductive substrate disposed between the first pressure sensitive adhesive layer and the second pressure sensitive adhesive layer. Suitable electrically conductive substrates and non-conductive substrates are described in detail below.

[0126] Methods of Making a Bonded Article and Methods of Debonding a Bonded Article

[0127] In a second aspect, the present disclosure provides a method of making a bonded article. The method comprises bonding a pressure sensitive adhesive article to an electrically conductive substrate, the pressure sensitive adhesive article comprising an electrically conductive composite layer having a first major surface and a second major surface, wherein the electrically conductive composite comprises an electrically conductive filler dispersed in a polymeric matrix; a first pressure sensitive adhesive layer disposed on the first major surface of the electrically conductive composite layer; and a second pressure sensitive adhesive layer disposed on the second major surface of the electrically conductive composite layer, wherein the second pressure sensitive adhesive comprises a polymerized ionic liquid; and wherein the second pressure sensitive adhesive layer is bonded to the electrically conductive substrate.Optionally, the method further comprises bonding the first pressure sensitive adhesive layer to an electrically non-conductive substrate.

[0128] It is to be understood that the term “electrically conductive substrate” encompasses both a conductive substrate and a combination of an electrically conductive coating on a non-conductive substrate.

[0129] A suitable pressure sensitive adhesive article may be according to any of the embodiments of the first aspect described in detail above.

[0130] In some cases, an adhesive bond may be strengthened by application of a series of electric potentials in opposite polarity across the pressure sensitive adhesive article, e.g., for a duration of from one second to four hours. For instance, following strengthening, the pressure sensitive adhesive article may exhibit a maximum strain of 300% or greater and a recovery’ of 50% or greater, as determined by the Creep Test Method, and / or the pressure sensitive adhesive article may exhibit an increase in adhesion strength of at least 40% following subjection to an alternating current, as determined by the Rheometer Adhesion Strengthening Test Method.

[0131] In certain embodiments, the series of electric potentials in opposite polarity has a voltage amplitude of 1 V to 1000 V, optionally 5 V to 1000 V, optionally 9 V to 1000 V, or optionally 10 V to 100 V. The series of electric potentials in opposite polarity optionally comprises an AC electric potential.The frequency of the AC electric potential may be less than 1000 Hz. optionally less than 500 Hz, optionally less than 100 Hz, optionally less than 75 Hz, optionally less than 60 Hz, or optionally less than 50 Hz. e.g., 0.01 Hz to 50 Hz.

[0132] In certain embodiments, the series of electric potentials in opposite polarity comprises a series of applied currents in opposite polarity, e.g., selected from the group consisting of polarity -switched DC voltages, sinusoidal waves, square waves, sawtooth waves, triangle waves, random noise, positive interference waves, and combinations thereof. In select cases, the series of applied currents are frequency -modulated waves and / or amplitude-modulated waves.

[0133] Methods for strengthening an adhesive bond and determining the extent of strengthening are described in detail in co-owned application Docket No. PA102224US01, incorporated herein by reference in its entirety.

[0134] In a third aspect, the present disclosure provides a method of debonding a bonded article. The method comprises applying an electrical potential between the electrically conductive substrate and a portion of the electrically conductive composite; and subsequently separating the electrically conductive substrate and the electrically non-conductive substrate.

[0135] Referring now to FIG. 8, a schematic cross-sectional view is provided of an exemplary electrically debondable bonded article 800. The bonded article 800 comprises a pressure sensitive adhesive article 810 comprising an electrically conductive composite layer 110 having a first major surface 112 and a second major surface 114; a first pressure sensitive adhesive layer 120 disposed on the first major surface 112 of the electrically conductive composite layer 110; and a second pressure sensitive adhesive layer 130 disposed on the second major surface 114 of the electrically conductive composite layer 110, wherein the second pressure sensitive adhesive 130 comprises a polymerized ionic liquid (not shown); and wherein the second pressure sensitive adhesive layer 130 is bonded to the electrically conductive substrate 140. The bonded article 800 further comprises an optional electrically non-conductive substrate 150 adhered to a major surface 122 of the first pressure sensitive adhesive layer 120.

[0136] In some embodiments, suitable electrically conductive substrates comprise a metal, a mixed metal, an alloy, a metal oxide, a composite metal, a conductive plastic, a conductive polymer, a polymer matrix containing an electrically conductive material dispersed in the matrix (e.g., as described in further detail above with respect to the electrically conductive composite layer), or combinations thereof. Such an electrically conductive layer 140 can be formed, for example, by plating, chemical vapor deposition, vacuum deposition, or sputtering. Polymer coatings may also be coated from solvent or aqueous solutions. The thickness of the electrically conductive layer 140 is not particularly limited. In some embodiments, the thickness of the electrically conductive layer 140 is 0.001 micrometers or larger, 0.01 micrometers or larger, 0.03 micrometers or larger, or 0.05 micrometers or larger. In some embodiments, the thickness of the electrically conductive layer 140 is 1,000 micrometers or less, 500 micrometers or less, 300 micrometers or less, 50 micrometers or less, or 10 micrometers or less. In some embodiments, the carrier is a polymeric film with a vapor-deposited aluminum film formed thereon.

[0137] FIG. 8 additionally depicts application of a (e.g.. DC) electrical potential 190 that forms a circuit between the electrically conductive composite layer 110 and the electrically conductive substrate 140. As shown, the electrically conductive composite layer 110 serves as the positive interface and the electrically conductive substrate 140 serves as the negative surface at which weaking of the adhesive bond occurs, e.g., an interface between a major surface 134 of the second pressure sensitive adhesive layer 130 and the electrically conductive substrate 140. Weakening of an adhesive bond may be measured, for example, according to the work of adhesion per surface area, thus making it easier to separate the pressure sensitive adhesive article 810 from die electrically conductive substrate 140.

[0138] Advantageously, little-to-no adhesive residue may remain on the electrically conductive substrate 140 after separation. In some embodiments, less than 10%. less than 5%, or less than 1% of the electrically debonding adhesive (by weight) remains on the electrically conductive substrate 140 after separation. In some embodiments, no adhesive remains on the electrically conductive substrate 140 after separation. In some embodiments, it is possible to reuse the electrically debonding adhesive allowing the pressure sensitive adhesive article 810 to be rejoined to the electrically conductive substrate 140 or adhered to a completely different substrate or article.

[0139] FIG. 9 provides a schematic cross-sectional view of another exemplary electrically debondable bonded article 900. The pressure sensitive adhesive article 910 comprises an electrically conductive composite layer 110; a first pressure sensitive adhesive layer 120 disposed on the electrically conductive composite layer 110; and a second pressure sensitive adhesive layer 130 disposed on the electrically conductive composite layer 110, wherein the second pressure sensitive adhesive 130 comprises a polymerized ionic liquid (not shown); and wherein the second pressure sensitive adhesive layer 130 is bonded to the electrically conductive substrate 140. The bonded article 900 comprises a pressure sensitive adhesive article 910 having a structure with a discontinuity 180, in particular, a notch 180 through the second pressure sensitive adhesive layer 130. The bonded article 900 further comprises an optional electrically non-conductive substrate 150 adhered to the first pressure sensitive adhesive layer 120.

[0140] As shown, the electrically conductive composite layer 110 serves as the positive interface, accessed via the discontinuity 180. and the electrically conductive substrate 140 serves as the negative surface at which weaking of the adhesive bond occurs, e.g.. an interface between the second pressure sensitive adhesive layer 130 and the electrically conductive substrate 140. As such, in certain embodiments, the electrical potential is applied to a portion of the electrically conductive composite exposed by at least one discontinuity.

[0141] In some embodiments, a suitable electrically non-conductive substrate is one of the following: a liner comprising a release agent, a backing, or a carrier.

[0142] Liners

[0143] Suitable (e.g., release) liners may comprise flexible paper and polymeric films having sufficient dimensional stability to hold layers formed thereon in position without excessive stretching. Suitable paper liners include, but arc not limited to, densified Kraft paper (commercially available from, forexample, Loparex North America, Willowbrook, IL), poly -coated paper such as polyethylene coated Kraft paper, and the like. Suitable polymeric film / liners include, but are not limited to, thermoplastic polymer films including polyalkylenes, e.g., polyethylene and polypropylene; polybutadiene, polyisoprene; polyalkylene oxides, e.g., polyethylene oxide; polyesters, e.g., PET and PBT; polyamides; polycarbonates, polystyrenes, block copolymers of any of the preceding polymers, and combinations thereof. Other suitable polymeric materials include polyimide, polysilicone, polytetrafluoroethylene, polyethylenephthalate, polyvinylchloride, or combinations thereof. Polymer blends of any of the above may also be employed, and nonwoven or woven liners may also be used.

[0144] In some embodiments, any or all of the major surfaces of a release liner may include a release coating, which may be the same or different, to tune or otherwise modify their release values. In various embodiments, which are not intended to be limiting, the release coatings applied to the major surfaces of the release liners may be selected from a fluorine-containing material, a silicone-containing material, a fluoropolymer, a silicone polymer, or a poly(meth)acrylate ester derived from a monomer including an alkyl (meth)acrylate having an alkyl group with 12 to 30 carbon atoms. In one embodiment, the alkyl group on the alkyl (meth) aery late can be branched. Illustrative examples of useful fluoropolymers and silicone polymers can be found in U. S. Patent No. 4,472,480 (Olson), U. S. Patent No. 4,567,073 and U. S. Patent No. 4,614,667 (both Larson et al), incorporated herein by reference in their entireties. Illustrative examples of useful poly(meth)acrylate esters can be found in U.S. Patent Appl. Publ. No. 2005 / 0118352 (Suwa), incorporated herein by reference in its entirety.

[0145] Carriers

[0146] The carrier film may be a flexible or inflexible backing material, a release liner, or a conductive carrier. Exemplary materials useful as the carrier film for the pressure sensitive adhesive articles of the disclosure include, but are not limited to, polyolefins such as polyethylene, polypropylene (including isotactic polypropylene and high impact polypropylene), polystyrene, polyester, including polyethylene terephthalate), polyvinyl chloride, poly(butylene terephthalate), poly(caprolactam), polyvinyl alcohol, polyurethane, poly(vinylidene fluoride), cellulose and cellulose derivatives, such as cellulose acetate and cellophane, and wovens and nonwovens. Commercially available carrier film include kraft paper (available from Monadnock Paper. Inc.); spun-bond poly(ethylene) and polypropylene), such as those available under the trade designations “TYVEK” and “TYPAR” (available from The Chemours Co.); and porous films obtained from poly(ethylene) and polypropylene), such as those available under the trade designations “TESLIN” (available from PPG Industries, Inc ), and “CELLGUARD” (available from Hoechst-Celanese). Exemplary conductive materials include for instance and without limitation, a layer of (e.g., metal) foil, a metal-coated polymeric film, a layer of a conductive primer coated onto or transferred onto the adhesive, a conductive primer deposited on a carrier layer, a conductive woven fabric, a conductive nonwoven fabric, a conductive mesh fabric (metal-coated insulative fibers), a conductive foam, a conductive elastomer, a conductive polymer film (e.g., poly(3,4-ethylenedioxythiophene), PEDOT) or coating on another film or polymer layer, and a conductive ceramic / alloy and / or oxides (e.g., Indium Tin Oxide, ITO) with or without a carrier layer.

[0147] The carrier film delivers the adhesive of the present disclosure to the desired substrate. The carrier film may comprise on the surface opposite the adhesive, a pigment, indicia, text, design, etc., which is then fixedly attached to the surface of the substrate or the carrier film may be free of such pigments and / or markings.

[0148] Backings

[0149] Adhesive compositions disclosed herein may advantageously be used to prepare a wide range of adhesive tapes and articles. Many of these tapes and articles contain backings or release liners used to support the layer of adhesive. As used herein a backing is a permanent support intended for final use of the adhesive article. A liner, on the other hand, is a temporary support that is not intended for final use of the adhesive article and is used during the manufacture or storage to support and / or protect the adhesive article. A liner is removed from the adhesive article prior to final use. To facilitate easy removal from the adhesive layer, the liner is typically coated with a release coating comprising a release agent. Such release agents are known in the art and are described, for example in " Handbook of Pressure Sensitive Adhesive Technology," D. Satas, editor, Van Nostrand Reinhold, New York, N. Y., 1989, pp. 585-600. In one embodiment, the release agent migrates to the surface (on the liner or release coating) to provide the appropriate release properties. Examples of release agents include carbamates, silicones and fluorocarbons. Illustrative examples of surface applied (i.e., topical) release agents include polyvinyl carbamates such as disclosed in U. S. Pat. No. 2,532,011 (Dahlquist et al.), reactive silicones, fluorochemical polymers, epoxysilicones such as are disclosed in U. S. Pat. Nos. 4,313,988 (Bany et al.) and 4,482.687 (Kessel et al.), polyorganosiloxane-polyurea block copolymers such as are disclosed in EP Pat. No. 0250248 Bl (Leir et al.), etc.

[0150] The backing layer may be a film, a non-woven web, paper, or a foam as further described below. The double-sided tape may comprise one or two release liners protecting the adhesive surface not in contact with the backing layer. In one embodiment, the adhesive layer is disposed between two release liners, which may be the same or different. In another embodiment, the adhesive layer is disposed on a backing and the opposing side of the backing comprises a release agent. The adhesive article is wound upon itself such that the exposed surface of the adhesive layer (opposite the backing) contacts the release-coated backing forming, for example, a roll of tape. In yet another embodiment, the adhesive is disposed between a backing and release liner. In some embodiments, the adhesive tapes and articles do not contain a backing and therefore are freestanding adhesive layers. Transfer adhesive tapes are an example of such an adhesive article. Transfer adhesive tapes, also called transfer tapes, have an adhesive layer delivered on one or more release liners. The adhesive layer has no backing within it. so once delivered to the target substrate and the liner is removed, there is only adhesive. Some transfer tapes are multi-layer transfer tapes with at least two adhesive layers that may be the same or different. Transfer tapes are widely used in the printing and paper making industries for making flying splices, as well as being used for a variety of bonding, mounting, and matting applications both by industry and by consumers.

[0151] Select Embodiments of the Disclosure

[0152] In a first embodiment, the present disclosure provides a pressure sensitive adhesive article. The pressure sensitive adhesive article comprises an electrically conductive composite layer having a first major surface and a second major surface, wherein the electrically conductive composite comprises an electrically conductive filler dispersed in a polymeric matrix. The pressure sensitive adhesive article further comprises a first pressure sensitive adhesive layer disposed on the first major surface of the electrically conductive composite layer; and a second pressure sensitive adhesive layer disposed on the second major surface of the electrically conductive composite layer. The second pressure sensitive adhesive comprises a polymerized ionic liquid.

[0153] In a second embodiment, the present disclosure provides a pressure sensitive adhesive article according to the first embodiment, wherein the electrically conductive filler comprises at least one of a metal, mixed metal, alloy, metal oxide, composite metal oxide, metal coated glass, an organometallic complex, graphene, graphite, carbon black, or other carbon-based filler.

[0154] In a third embodiment, the present disclosure provides a pressure sensitive adhesive article according to die first embodiment or the second embodiment, wherein the electrically conductive filler comprises a carbon-based filler.

[0155] In a fourth embodiment, the present disclosure provides a pressure sensitive adhesive article according to the first through third embodiments, wherein the electrically conductive filler comprises at least one of conductive carbon black, carbon nanotubes, aluminum, copper, nickel, platinum, silver, gold, zinc, chromium, cobalt, iron, carbon fibers, carbon nanofibers, carbon nanotubes, graphite, graphene, a phthalocyanine pigment, anthraquinone, indigoid, quinacridone, or a dioxazine pigment.

[0156] In a fifth embodiment, the present disclosure provides a pressure sensitive adhesive article according to the first through fourth embodiments, wherein the electrically conductive filler comprises conductive carbon black.

[0157] In a sixth embodiment, the present disclosure provides a pressure sensitive adhesive article according to the first through fifth embodiments, wherein the polymeric matrix of the electrically conductive composite layer comprises a poly(meth)acrylate, a polyurethane, a polyethylene, a polypropylene, a polyacrylonitrile, a polyimide, a polyvinyl chloride, chlorinated polyolefin, a polystyrene, a polyvinyl butyral, polyvinyl acetate, a polyester, a polyamide, polycarbonate, an alkyd resin, an epoxy resin, a phenolic resin, a natural rubber, a synthetic rubber, a silicone rubber, or combinations thereof.

[0158] In a seventh embodiment, the present disclosure provides a pressure sensitive adhesive article according to the first through sixth embodiments, wherein the second pressure sensitive adhesive layer comprises at least one polymer selected from the group consisting of a (meth)acrylic polymer, a rubber-based polymer, a vinyl alkyl ether-based polymer, a silicone -based polymer, a polyester-based polymer, a polyamide-based polymer, and a urethane-based polymer,; and an ionic liquid covalently attached to at least one polymer of the second pressure sensitive adhesive.

[0159] In an eighth embodiment, the present disclosure provides a pressure sensitive adhesive article according to the first through seventh embodiments, wherein the first pressure sensitive adhesive layer is essentially free of a polymerized ionic liquid.

[0160] In a ninth embodiment, the present disclosure provides a pressure sensitive adhesive article according to the first through eighth embodiments, wherein the first pressure sensitive adhesive layer is essentially free of an ionic liquid.

[0161] In a tenth embodiment, the present disclosure provides a pressure sensitive adhesive article according to the first through seventh embodiments, wherein the first pressure sensitive adhesive layer comprises a polymerized ionic liquid.

[0162] In an eleventh embodiment, the present disclosure provides a pressure sensitive adhesive article according to the first through tenth embodiments, wherein the first pressure sensitive adhesive layer comprises a different polymer than the second pressure sensitive adhesive layer.

[0163] In a twelfth embodiment, the present disclosure provides a pressure sensitive adhesive article according to the first through eleventh embodiments, wherein the conductive composite layer exhibits a Young’s modulus of at least 0.1, 1, 10, 100, 200, or 300 MPa, as determined by Tensile DMA or uniaxial tensile testing.

[0164] In a thirteenth embodiment, the present disclosure provides a pressure sensitive adhesive article according to the first through twelfth embodiments, wherein the conductive composite layer is one continuous layer of the electrically conductive filler dispersed in the polymeric matrix.

[0165] In a fourteenth embodiment, the present disclosure provides a pressure sensitive adhesive article according to the first through thirteenth embodiments, wherein the first pressure sensitive adhesive layer comprises the same polymer as the second pressure sensitive adhesive layer.

[0166] In a fifteenth embodiment, the present disclosure provides a pressure sensitive adhesive article according to the first through fourteenth embodiments, wherein each of the first pressure sensitive adhesive layer and the second pressure sensitive adhesive layer independently has an average thickness of 50 micrometers to 2500 micrometers.

[0167] In a sixteenth embodiment, the present disclosure provides a pressure sensitive adhesive article according to the first through fifteenth embodiments, wherein at least one of the first pressure sensitive adhesive layer or the second pressure sensitive adhesive layer has an average thickness of 10 micrometers to 400 micrometers.

[0168] In a seventeenth embodiment, the present disclosure provides a pressure sensitive adhesive article according to the first through sixteenth embodiments, wherein the polymerized ionic liquid comprises at least one of a nitrogen-containing ion, a phosphonium ion, a sulfonium ion, an imidazolium ion, a pyridinium ion, or an iodonium ion.

[0169] In an eighteenth embodiment, the present disclosure provides a pressure sensitive adhesive article according to the first through seventeenth embodiments, wherein the second pressure sensitive adhesive comprises a poly merized ionic liquid whose ionic liquid precursor comprises an ionic liquid and the polymerizable functional group of the cation of the ionic liquid comprises at least one of a (mcth)acrylatcgroup, a (meth)acrylamide group, a vinyl group, an alcohol group, an epoxy group, a primary or secondary amino group, or a thiol group.

[0170] In a nineteenth embodiment, the present disclosure provides a pressure sensitive adhesive article according to the first through eighteenth embodiments, wherein the polymerized ionic liquid comprises at least one of a sulfate, a sulfonate, a carboxylate, a phosphate, a borate, an imide, an imidazole, a bis(sulfonyl)imide, a halide anion, a methide, a nitrate ion, a nitrite ion, a tricyanomethanide, a phosphorus-containing ion, or a dicyanamide.

[0171] In a twentieth embodiment, the present disclosure provides a pressure sensitive adhesive article according to the first through nineteenth embodiments, wherein second pressure sensitive adhesive comprises a polymerized ionic liquid whose ionic liquid precursor comprises an ionic liquid wherein the polymerizable functional group of the anion of the ionic liquid comprises at least one of a (meth)acrylate group, a (meth) acrylamide group, a vinyl group, an alcohol group, an epoxy group, a primary or secondary amino group, or a thiol group.

[0172] In a twenty-first embodiment, the present disclosure provides a pressure sensitive adhesive article according to the first through tw entieth embodiments, wherein an electrical lead is attached to a portion of the electrically conductive composite layer.

[0173] In a twenty-second embodiment, the present disclosure provides a pressure sensitive adhesive article according to the first through twentieth embodiments, wherein the first pressure sensitive adhesive layer is electrically conductive and wherein an electrical lead is attached to a portion of the first pressure sensitive adhesive layer.

[0174] In a twenty-third embodiment, the present disclosure provides a pressure sensitive adhesive article according to the first through twentieth embodiments, wherein at least one of the first pressure sensitive adhesive layer or the second pressure sensitive adhesive layer has at least one discontinuity.

[0175] In a twenty-fourth embodiment, the present disclosure provides a pressure sensitive adhesive article according to the twenty -third embodiment, wherein the discontinuity comprises an aperture through either the first pressure sensitive adhesive layer or the second pressure sensitive adhesive layer, wherein the aperture is spaced apart from a perimeter of the first or second pressure sensitive adhesive layer.

[0176] In a twenty-fifth embodiment, the present disclosure provides a pressure sensitive adhesive article according to the tw enty -third embodiment, wherein the discontinuity comprises a notch through either the first pressure sensitive adhesive layer or the second pressure sensitive adhesive layer, wherein the notch interrupts a perimeter of the first or second pressure sensitive adhesive layer.

[0177] In a twenty-sixth embodiment, the present disclosure provides a pressure sensitive adhesive article according to the twenty -third through twenty -fifth embodiments, w herein an electrical lead is attached to a portion of the electrically conductive composite layer exposed by the at least one discontinuity.

[0178] In a twenty-seventh embodiment, the present disclosure provides a pressure sensitive adhesive article according to the first through twenty-sixth embodiments, wherein at leat one of the first pressuresensitive adhesive layer or the second pressure sensitive adhesive layer further comprises an additive comprising at least one of a tackifier, a plasticizer, an adhesion promoter, a stabilization agent, a corrosion inhibitor, a colorant, an antioxidant, a polymer having a glass transition temperature of at least 40 degrees Celsius, or a filler.

[0179] In a twenty-eighth embodiment, the present disclosure provides a method of making a bonded article. The method comprises bonding a pressure sensitive adhesive article to an electrically conductive substrate. The pressure sensitive adhesive article comprises an electrically conductive composite layer having a first major surface and a second major surface, wherein the electrically conductive composite comprises an electrically conductive filler dispersed in a polymeric matrix. The pressure sensitive adhesive article further comprises a first pressure sensitive adhesive layer disposed on the first major surface of the electrically conductive composite layer; and a second pressure sensitive adhesive layer disposed on the second major surface of the electrically conductive composite layer. The second pressure sensitive adhesive comprises a polymerized ionic liquid. The second pressure sensitive adhesive layer is bonded to the electrically conductive substrate.

[0180] In a twenty -ninth embodiment, the present disclosure provides a method of making a bonded article according to the twenty-eighth embodiment, further comprising bonding the first pressure sensitive adhesive layer to an electrically non-conductive substrate.

[0181] In a thirtieth embodiment, the present disclosure provides a method of making a bonded article according to the twenty-eighth embodiment or the twenty-ninth embodiment, wherein the pressure sensitive adhesive article is according to any of the second through tw entieth embodiments.

[0182] In a thirty -first embodiment, the present disclosure provides a method of debonding a bonded article made by the method of the twenty -ninth embodiment. The method comprises applying an electrical potential between the electrically conductive substrate and a portion of the electrically conductive composite and subsequently separating the electrically conductive substrate and the electrically non-conductive substrate.

[0183] In a thirty -second embodiment, the present disclosure provides a method of debonding a bonded article according to the thirty -first embodiment, wherein the pressure sensitive adhesive article is according to any of the twenty-third through twenty -sixth embodiments and the electrical potential is applied to a portion of the electrically conductive composite exposed by the at least one discontinuity.

[0184] In a thirty -third embodiment, the present disclosure provides a method of debonding a bonded article according to the thirty -first embodiment or the thirty -second embodiment, wherein the electrically conductive substrate comprises a metal, a mixed metal, an alloy, a metal oxide, a composite metal, a conductive plastic, a conductive polymer, a polymer matrix containing an electrically conductive material dispersed in the matrix, or combinations thereof.

[0185] In a thirty -fourth embodiment, the present disclosure provides a pressure sensitive adhesive article. The pressure sensitive adhesive article comprises an electrically conductive first pressure sensitive adhesive layer and a second pressure sensitive adhesive layer disposed adjacent to theelectrically conductive first pressure sensitive adhesive layer. The second pressure sensitive adhesive comprises a polymerized ionic liquid.

[0186] In a thirty -fifth embodiment, the present disclosure provides a pressure sensitive adhesive article according to the thirty -fourth embodiment further comprising a non-conductive substrate disposed between the first pressure sensitive adhesive layer and the second pressure sensitive adhesive layer.

[0187] In a thirty -sixth embodiment, the present disclosure provides a pressure sensitive adhesive article according to the thirty -fourth embodiment or the thirty -fifth embodiment, wherein the first pressure sensitive adhesive layer comprises an electrically conductive filler dispersed in a pressure sensitive adhesive.

[0188] In a thirty-seventh embodiment, the present disclosure provides a pressure sensitive adhesive article according to any of the first through twenty -seventh or thirty -fourth through thirty-sixth embodiments, wherein the adhesive composition exhibits a maximum strain of 300% or greater and a recovery of 50% or greater, as determined by the Creep Test Method.

[0189] In a thirty -eighth embodiment, the present disclosure provides a pressure sensitive adhesive article according to any of the first through twenty-seventh or thirty-fourth through thirty-seventh embodiments, wherein the adhesive composition exhibits an increase in adhesion strength of at least 40% following subjection to an alternating current, as determined by the Rheometer Adhesion Strengthening Test Method.EXAMPLES

[0190] Unless otherwise noted or readily apparent from the context, all parts, percentages, ratios, etc. in the Examples and the rest of the specification are by weight. Table 1 (below) lists materials used in the examples and their sources:Table 1. Materials ListAbbreviation Description2-EHA 2-ethylhexyl acry late, obtained from BASF, Florham Park, New Jersey, USA BA n-Butyl acry late, obtained from BASF, Florham Park, New Jersey, USA NNDMA N, N-dimcthylacry lamidc, obtained from TCI America, Portland, OR, USA NVP N-vinyl pyrrolidone, obtained from TCI America, Portland, OR, USA Polyethylene glycol) methyl ether acrylate, Mn = 550 Da obtained from Osaka PEG-AOrganic Chemicals / San Esters, Osaka, JapanS4630 is a hollow glass microsphere with a diameter of ca. 40 pm, a density of S4630 0.46 g / cc, and a crush strength of 16,000 psi obtained from 3M Company, St.Paul, Minnesota, USAHDDMA 1,6-hexanediol-dimethacrylate, obtained from Arkema, Colombes, France2,2-Dimethoxy-1,2-diphenylethane-1-one, sold under the trade name Irgacure 651651, obtained from Ciba Specialty Chemicals, Bassel, Switzerland N, N. N-Trimethyl ammonium ethyl acrylate bis(fluorosulfonyl)imide, TMAEA FSI synthesized as described for DMAEAM FSI by Moughton et al in W02023 / 228050 AlSulfopropyl acrylate N-butyl-N'-methyl imidazolium synthesized as described SPA BMIherein.Sulfopropyl acrylate N-octyl-N'-methyl imidazolium synthesized as described SPA OMIherein.Sulfopropyl acrylamide N-butyl-N'-methyl imidazolium synthesized as described SPACM BMIherein.SPA K Sulfopropyl acrylate potassium salt, obtained from TCI America2-Acrylamido-2-methyl-l-propanesulfonic acid sodium salt solution, obtained SPAC Nafrom MilliporeSigma, Burlington, Massachusetts, USABMI Cl N-Butyl-N'-methyl-imidazolium chloride, obtained from TCI America,l-Methyl-3-octylimidazolium chloride, obtained from Sigma Aldrich, St. Louis, OMI ClMissouri, USAl-Butyl-3-methylimidazolium hexafluorophosphate, obtained from Sigma BMI PF6Aldrich, St. Louis, Missouri, USA3M™ VHB™ Electronic Tape 86415 is a 0.15 mm (0.006 in) black, acrylic foam 3M VHB 86415 tape used for bonding a wide range of materials in the electronics industry.Obtained from 3M Company, St. Paul, Minnesota, USA3M™ VHB™ Tape 4941 is a 1,125 mm (0.045 in) thick gray double sided 3M VHB 4941 conformable acrylic foam tape used to bond a wide range of substrates. Obtained from 3M Company, St. Paul, Minnesota, USA3M™ VHB™ Tape 4950 is a 1,125 mm (0.045 in) thick double sided acrylic 3M VHB 4950 tape with a firm foam core that offers high strength and vibration / fatigue resistance. Obtained from 3M Company. St. Paul, Minnesota, USA An omnidirectional conductive sponge 0.3 mm thick from Yufreyoo based on Conductive polyurethane foam sponge with electrodeposited nickel, copper, and other metals Foam-1 to make the sponge conductive in all directions. Surface resistance: 0.05 Q.Obtained from Yufreyoo, Sichuan, China.Super P Carbon Conductive carbon black (>96% carbon black) obtained from Irncrys, Paris, Black FranceSolvent-free wetting and dispersing additive for dispersing and stabilizing BYKJET 9152 organic pigments and carbon blacks in solvent-borne obtained from BYK, Wesel,Germany3M VHBSolvent based primer used to promote adhesion to polypropylene, ABS, UniversalPET / PBT, obtained from 3M Company, St. Paul, MN, USAPrimer2-mil (50 pm) biaxially oriented PET film from 3M Company, St. Paul, MN was Plasma Treatedplasma treated (as per conditions described in U. S. Pat. No. 10,134,566 (David et 2 mil PET Filmal.)50 micron PET with a coating of aluminum on one side, obtained as Mylar film Al PETfrom HFS, Azusa, CA USA2 mil thick PET release liner, obtained under product name RF12N from SKC, RF12NSeoul, Korea2 mil thick PET release liner, obtained under product name RF02N from SKC, RF02NSeoul, Korea

[0191] Preparation of SPA BMI0LII o'0N-yA round bottom flask was equipped with a TEFLON-coated stir bar and charged with 3-sulfopropyl acrylate potassium salt (10 g), 1-butyl-3-methylimidazolium chloride (7.52g), and deionized water (10 g). The solution was stirred for 15.5 hours and then was precipitated into 900 mL of acetone. The solvent was filtered through a bed of celite. The solvent was removed by rotary evaporation under reduced pressure to yield SPA BMI as a clear liquid, which was further dried under a stream of air. 'H-NMR (500 MHz; DMSO-d6): δ 9.24 (s, 1H), 7.81 (t, J = 1.8 Hz, 1H), 7.74 (t, J= 1.7 Hz, 1H), 6.30 (dd, J = 17.3, 1.6 Hz, 1H), 6.16 (dd, J= 17.3, 10.3 Hz, 1H), 5.93 (dd, J= 10.3, 1.6 Hz, 1H), 4.19-4.16 (m, 4H), 3.86 (s, 3H), 2.50 (dd, J= 8.3, 6.8 Hz, 2H), 1.94-1.88 (m, 2H), 1.79-1.73 (m, 2H), 1.24 (dq, J= 15.0, 7.5 Hz, 2H), 0.88 (t, J= 7.4 Hz, 3H). 13-C NMR (126 MHz; DMSO): 5 165.6, 136.7, 131.4, 128.4, 123.7, 122.3, 63.6, 48.5, 47.9, 35.7, 31.5, 24.9, 18.8, 13.3.A round bottom flask was equipped with a TEFLON-coated stir bar and charged with 3-sulfopropyl acrylate potassium salt (10 g), 1-octyl-3-methylimidazolium chloride (9.93g), and deionized water (15 g).The solution was stirred for 48hours and then was precipitated into 900 mL of acetone. The solution was filtered through filter paper and removed by rotary evaporation under reduced pressure to yield SPA OMI (14.25 g. 85% yield) as a clear liquid. 'H-NMR (500 MHz; DMSO-d6): δ 9.22 (s, 1H). 7.81 (t, J= 1.8 Hz, 1H), 7.74 (t, J = 1.7 Hz, 1H), 6.31 (dd, J= 17.3, 1.6 Hz, 1H), 6.17 (dd, J= 17.3, 10.3 Hz, 1H), 5.94 (dd, J= 10.3, 1.6 Hz, 1H), 4.17 (td, J= 7.0, 3.8 Hz, 4H), 3.87 (s, 3H), 2.52-2.49 (m, 2H), 1.94-1.89 (m, 2H). 1.78 (quintet,.7= 7.2 Hz. 2H), 1.29-1.20 (m, 1 OH), 0.85 (t..7= 7.0 Hz, 3H). 13-C NMR (126 MHz; DMSO): 5 165.5. 136.7, 131.4, 128.4, 123.6. 122.3, 63.6. 48.8, 47.9, 35.7. 31.2, 29.5, 28.6. 28.4, 25.6, 24.9, 22.1, 14.0.

[0193] Preparation of SPACM BMIA round bottom flask was equipped with a TEFLON-coated stir bar and charged with 2-acry lamido-2-mcthyl-l-propancsulfonic acid sodium salt solution (30 g of a 50 wt.% solution in water) and l-butyl-3-methylimidazolium chloride (11.42 g). The solution was stirred for 48 hours and then was precipitated into 900 mL of acetone. The solution was filtered and removed by rotary evaporation under reduced pressure to yield SPACM BMI (21.2 g, 96% yield) as a clear liquid. 'H-NMR (500 MHz; DMSO-d6): δ 9.20 (s, 1H), 8.37 (s, 1H), 7.80 (t, J= 1.7 Hz, 1H), 7.73 (t, J= 1.7 Hz. 1H), 6.07 (dd. J= 17.1, 10.0 Hz, 1H), 5.96 (dd, J= 17.1, 2.2 Hz, 1H), 5.50 (dd, J= 10.0, 2.2 Hz. 1H), 4.18 (t, J= 7.2 Hz, 2H), 3.87 (s, 3H), 2.78 (s. 2H), 1.79-1.73 (m, 2H), 1.44 (s, 6H), 1.25 (dd, J= 15.1, 7.5 Hz, 2H). 0.89 (t, J= 7.4 Hz, 3H). 13-C NMR (126 MHz; DMSO): 5 163.8, 136.7, 133.4, 124.0, 123.7. 122.3, 60.0, 51.7, 48.5, 35.8, 31.5, 26.1. 18.8, 13.3.

[0194] Preparation of Conductive Primer-1 on PET Release Liner3M VHB Universal Primer UV was used as received and Super P conductive carbon black and BYKJET 9152 dispersant were both mixed into the primer at 4000 rpm using a Dayton Lab Mixer. The carbon black and dispersant were both added at 2.5 wt.% each to give a conductive primer composition of 95 / 2.5 / 2.5 by wt.% of primer solution / carbon black / dispersant. The conductive primer solution was coated onto RF12N PET release liner and dried at 70 °C for 5 minutes to obtain a dry conductive primer thickness of 7 microns.Test Methods

[0195] Peel Adhesion Testing (“Peel Adhesion Test Method”)For all peel adhesion testing, the remaining RF12N release liner (SKC Haas Display Films LLC, Seoul KR) was removed from the multi-layer-PET construction as outlined below, and the exposed side of thetacky adhesive transfer tape was rolled by hand lamination using a 6 inch (15 cm) rubberized hand roller. (Polymag Tek. NY) onto a 6 inch (15 cm) wide primed polyester film backing (3M Company, St. Paul. MN), 2-mil (50 pm) biaxially oriented PET film with plasma treatment (conditions described in U. S. Pat. No. 10.134,566 (David et al.)) ensuring no air bubbles were trapped between the adhesive and the primed polyester film. Peel adhesion was measured at an angle of 180 degrees. Peel adhesion testing was performed on annealed 18-gauge, 304 stainless steel (“SS”) from Chem. Instruments. Fairfield, OH). SS test panels were cleaned with methyl ethyl ketone before and after testing. Peel testing was done using an SP-2300 iMass (iMass Inc., Accord. MA USA) at a rate of 12 inches / min (0.3 m / min) after a dwell time of 1 day. The RF12N release liner (SKC Haas Display Films LLC, Seoul KR) was removed from the tapes on PET backings and the adhesives were laminated directly to the 2-inch x 6-inch (5.08 cm x 15.24 cm) substrate using a weighted rubberized (4.5 lb, 2.04 kg) hand roller with four repetitions of 3 -second roll downs. This method followed ASTM D3330 / D3330M-04(2018), test method A, liner side, All samples and substrates were conditioned in a controlled temperature and humidity (“CTH”) room (set at 23°C, 50% RH (relative humidity)) prior to peel testing, except for non CTH conditioned peel testing of ML-CE1. ML-CE1 was subjected to conditions as documented in table 6.

[0196] Electrical Debonding Peel TestingFor electro debonded peel adhesion testing for multi-layer samples (i.e. ML-E1 through ML-E8, and ML-CE1), the same test method was used as described above for peel adhesion testing, except a 20 min dwell on SS in a CTH room was used instead of 1 day dwell in a CTH room. Also, the electrically debondable adhesive (i.e. A through E adhesive composition) was laminated to directly contact the stainless steel to facilitate electrical debonding of that adhesive side from the stainless steel substrate. To electrically debond the peel adhesion samples, a BK Precision 1685 B power source was connected to the conductive B core layer (or the Al side of the Al PET backing within ML-CE1) within the multi-layer tape (e.g. conductive foam-1 in ML-E2) and the SS panel via a positive and negative electrode, respectively. For 60 seconds, a voltage of 50 V was applied across the adhesive tape conductive core layer and the SS substrate. Immediately after this time, the samples were disconnected from the power source electrodes and loaded onto an iMass peel tester using an SP-2300 iMass (iMass Inc., Accord, MA USA) and tested for 180-degree peel adhesion at a rate of 12 inches / min (0.3 m / min) after a total dwell time of 20 minutes, excluding the 1 minute debonding time.

[0197] Adhesive Transfer Tape (Adhesive between liners) Sample PreparationMonomer-polymer mixtures were made by combining the raw materials listed in Table 2 within a glass jar and partially polymerizing the mixture by exposing the jar to 0.3 mW / cm2UV-LED irradiation (365 nm) until the mixture had a higher viscosity (about 1000 cP). Curable compositions were made by combining the components listed in Table 3. The designated monomer-polymer mixture, i.e., MP-X was used at 100 wt.% or 100 parts and the rest of the components listed in Table 3 were added at the amounts listed by calculating the parts per hundred (ppr or phr) based on the amount of the MP-X. Then eachcurable composition (MP-A and MP-B) was coated between two release liners (RF12N and RF02N). The samples were then cured under 365 nm UV-LED lights with a total dosage of 3.1 J / cm2as measured with a radiometer equipped with a high-power sensing head (available under the trade designation “POWER PUCK II” from EIT Incorporated. Sterling. VA). resulting in adhesive transfer tapes (or ATTs) labelled A through F which had an adhesive layer thickness of 2, 2.4, and 8 mil (5060 and 200 pm) as listed in Table 3.

[0198] Multi-layer Sample (ML-E1, ML-E2, ML-E3, ML-E4, ML-E5, ML-E6, ML-E7, ML-E8) Tape Preparation for Peel Adhesion Testing

[0199] ML-E1 was made as follow s: adhesive transfer tape, B was cut into a 1” by 3” (2.54 cm by 7.62 cm) rectangle. The RF02N release liner (SKC Haas Display Films LLC. Seoul KR) of adhesive transfer tape B was first removed and the exposed tacky adhesive surface was laminated / rolled by hand onto to 3” (7.62) wide piece of 2 mil (50.8 micrometers) plasma primed PET backing using a 6 inch (1 cm) rubberized hand roller, (Polymag Tck, NY) ensuring no air bubbles were trapped between the adhesive and the PET backing. The remaining RF12N liner of the B adhesive transfer tape / PET backing was then removed to expose the other side of the tacky B adhesive. Then a 1” by 3” (2.54 cm by 7.62 cm) rectangle of the conductive primer- 1 on RF12N was placed primer side down onto the exposed tacky side of adhesive B and laminated / rolled by hand using a 6 inch (15 cm) rubberized hand roller, (Polymag Tek, NY) ensuring no air bubbles were trapped between the adhesive and the conductive primer-1. The RF12N liner of the conductive primer-1 construction was then removed, transferring the conductive primer layer (without the RF12N liner) onto the B adhesive layer. Then one more piece of adhesive transfer tape, B was cut into a 1” by 2.5” (2.54 cm by 6.35 cm) rectangle. The RF02N release liner (SKC Haas Display Films LLC, Seoul KR) of the B transfer tape was first removed and the exposed tacky adhesive surface was laminated / rolled by hand onto to the conductive primer side of the backing / B transfer tape / primer construction using a 6 inch (15 cm) rubberized hand roller, (Polymag Tek, NY) ensuring no air bubbles were trapped between the B adhesive and the conductive primer, also ensuring that 0.5” (1.27 cm) of the conductive primer- 1 was left uncovered by B to enable electrical contact to be made w ith it when doing electro debonding in peel mode. The RF12N liner of the construction was then removed to adhere the multi-layer tape construction with plasma primed backing to stainless steel to perform peel adhesion testing with and without electrical debonding, as described in the test methods section.ML-E2 was made in a similar manner as described for ML-E1, except instead of the B transfer tape being used it was A transfer tape laminated either side of conductive foam-1, also ensuring that 0.5” (1.27 cm) of the conductive foam-1 w as left uncovered by A to enable electrical contact to be made with it when doing electro debonding in peel mode. ML-E4 through ML-E6 w ere made in the exactly the same way as ML-E1, except adhesive C was used instead of B for ML-E4. For ML-E5, adhesive D was used instead of B and for ML-E6, adhesive E was used instead of B.ML-E3 was made as follows, 3M 86415 VHB foam tape was cut into a 1” by 3” (2.54 cm by 7.62 cm) rectangle. The easy side release liner of the 3M 86415 transfer tape was first removed and theexposed tacky adhesive surface was laminated / rolled by hand onto to 3” (7.62 cm) wide piece of 2 mil plasma primed PET backing using a 6 inch (15 cm) rubberized hand roller, (Polymag Tek, NY) ensuring no air bubbles were trapped between the adhesive and the PET backing. The tight release side liner of the 3M VHB 86415 transfer tape / backing construction was then removed to expose the other side of the 86415 adhesive tape. Then a 1” by 3” (2.54 cm by 7.62 cm) rectangle of the conductive primer-1 on RF12N was placed primer side down onto the exposed tacky adhesive and laminated / rolled by hand using a 6 inch (15 cm) rubberized hand roller, (Polymag Tek. NY) ensuring no air bubbles were trapped between the 86415 adhesive and the conductive primer- 1. The RF12N liner of the conductive primer- 1 construction was then removed, transferring the conductive primer layer onto the 3M 86415 adhesive layer. Then adhesive transfer tape, A was cut into a 1” by 2.5” (2.54 cm by 6.35 cm) rectangle and the RF02N release liner (SKC Haas Display Films LLC, Seoul KR) of the adhesive transfer tape A was first removed and the exposed tacky adhesive surface was laminated / rolled by hand onto to the primer side of the conductive primer-l / 3M 86415 / plasma primed PET backing construction using a 6 inch (15 cm) rubberized hand roller, (Polymag Tek, NY) ensuring no air bubbles were trapped between the adhesive A and the conductive primer, also ensuring that 0.5” (1.27 cm) of die conductive primer-1 was left uncovered by A to enable electrical contact to be made with it when doing electro debonding in peel mode. ML-E7 and ML-E8 were made in the exact same way as ML-E3. except 3M 4941 and 3M 4950 (respectively) were used instead of 3M 86415.ML-CE1 was made as follows, adhesive transfer tape, F was cut into a 1” by 3” (2.54 cm by 7.62 cm) rectangle. The RF02N release liner (SKC Haas Display Films LLC, Seoul KR) of adhesive transfer tape F was first removed and the exposed tacky adhesive surface was laminated / rolled by hand onto to the Al side of a 3” (7.62 cm) wide piece of 2 mil (50.8 micrometers) Al PET backing using a 6 inch (15 cm) rubberized hand roller, (Polymag Tek, NY) ensuring no air bubbles were trapped between the adhesive and the Al PET backing. The remaining RF12N liner was removed when adhering the sample to stainless steel, as noted further within the peel adhesion test method.Table 2. Composition of monomer polymer mixtures, MP-X, _Monomer Polymer Mixtures (MP-X) phrMP ID 2-EHA BA NNDMA NVP HDDMA Irg Wt % Wt % Wt % Wt % 651MP-A 50 15 25 10 0.02 0.025MP-B 80 20 0 0.025Table 3. Composition of adhesive transfer tapes, ATTs.Additives to MP-X(Amounts in parts per hundred resin, or phr, relative to 100 parts of MP-X)Adhesive Monomer Wt.% in parentheses is relative to polymerizable components only ATTID Thickness Polymer(pm) ID Additive-1 Additive-2 Additive-3Phr HDDMA IRG Phr Phr 651 Type Type Type (wt. (phr) (wt.%) (wt.%) (Phr)%)TMAE 15 20A 50 PEGA S4630 10 0.10 0.2 A FSI (11 1) (148)TMAE 15 20B PEGA S4630 10 0.10 0.2 AFSI (H.l) (14.8)MP-A SPA 20C PEGA 5 (4.0) 0.075 0.2 OMI (16.0)TMA 200 10 10 10 SPAD EA PEGA 0.075 0.2 OMI (7.7) (77) (7.7)FSI10 SPAC 10E MP-B PEGA 0.075 0.2 MBMI (8.3) (83)BMI15 F 60 MP-A PEGA 10 0.1 0.2 PF6Table 4. Composition of multi-layer adhesive tape examples (ML-EX) made with conductive composite cores, B. and adhesive transfer tapes from Table 3 and commercially available adhesive tapes from table 1.Skin, A Skin, C ABC Conductive Core, BABC Multilayer Multilayer Total ATT Thickness Thickness Thickness Composition ATT IDExam Thickne ID (pm) (pm) (pm) pie ss(pm)ConductiveML-E1 407 B 200 7 B 200Primer- 1Conductive300 A 50 ML-E2 400 A 50Foam-1Conductive 3MML-E3 202 A 50 7 150Primer- 1 86415ConductiveML-E4 407 200 7 200 C CPrimer- 1ConductiveML-E5 407 D 200 7 D 200Primer- 1ConductiveML-E6 407 E 200 7 E 200Primer- 1Conductive 3M ML-E7 1.182 A 50 7 1,125Primer- 1 4941Conductive 3MML-E8 1.182 A 50 7 1,125Primer- 1 4950Table 5. Test results for 180-degree peel adhesion to SS with and without electro debonding. Failure modes are adhesive (i.e. clean removal from SS substrate), unless stated otherwise.Peel Adhesion to SS Peel Adhesion Peel reduction Multi-layer (12” / min), after 1 min at 50Example 20 min dwell CTH V after 1 min at 50 (N / mm) (N / mm) VML-E1 1.47 (adhesive) 0.03 98% ML-E2 0.34 (foam split) 0.01 97% ML-E3 1.06 (foam split) 0.03 97% ML-E4 1.41 0.55 (1 day) 61% (5 min) ML-E5 1.05 0.33 69% ML-E6 1.32 0.05 96% ML-E7 2.68 0.02 99% ML-E8 2.99 0.01 99%Table 6. Test results for 180-degree peel adhesion to SS with and without electro debonding. Failure modes are adhesive (i.e. clean removal from SS substrate), unless stated otherwise.Observations after 2 weeks Peel Peel Adhesion after 1 min of 85C / 85% Adhesion to at 50 V (N / mm)MultiRH ATT SS conditioning layer Backing (12” / min),ID CTH20 min dwellExample conditioned 65C / 90%RHCTH for 20 conditioned(N / mm) for 3 daysminutes prior toprior todebonding debonding0.3 N / mm Corrosion of 0.2 (adhesive (adhesive Al layer by ML-CE1 F Al PET 0.01delamination) delamination CE1 from the from metal) Al PET

[0200] Other modifications and variations to the present disclosure may be practiced by those of ordinary skill in the art, without departing from the spirit and scope of the present disclosure, which is more particularly set forth in the appended claims. It is understood that aspects of the various embodiments may be interchanged in whole or part or combined with other aspects of the variousembodiments. All cited references, patents, or patent applications in the above application for letters patent are herein incorporated by reference in their entirety in a consistent manner. In the event of inconsistencies or contradictions betw een portions of the incorporated references and this application, the information in the preceding description shall control. The preceding description, given in order to enable one of ordinary skill in the art to practice the claimed disclosure, is not to be construed as limiting the scope of the disclosure, w hich is defined by the claims and all equivalents thereto.

Claims

What is claimed is:

1. A pressure sensitive adhesive article comprising:an electrically conductive composite layer having a first major surface and a second major surface, wherein the electrically conductive composite comprises an electrically conductive filler dispersed in a polymeric matrix;a first pressure sensitive adhesive layer disposed on the first major surface of the electrically conductive composite layer; anda second pressure sensitive adhesive layer disposed on the second major surface of the electrically conductive composite layer, wherein the second pressure sensitive adhesive comprises a polymerized ionic liquid.

2. The pressure sensitive adhesive article of claim 1, wherein the electrically conductive filler comprises at least one of a metal, mixed metal, alloy, metal oxide, composite metal oxide, metal coated glass, an organometallic complex, graphene, graphite, carbon black, or other carbon-based filler.

3. The pressure sensitive adhesive article of claim 1 or claim 2, wherein the electrically conductive filler comprises a carbon-based filler.

4. The pressure sensitive adhesive article of any of claims 1 to 3, wherein the electrically conductive filler comprises at least one of conductive carbon black, carbon nanotubes, aluminum, copper, nickel, platinum, silver, gold, zinc, chromium, cobalt, iron, carbon fibers, carbon nanofibers, carbon nanotubes, graphite, graphene, a phthalocyanine pigment, anthraquinone, indigoid, quinacridone, or a dioxazine pigment.

5. The pressure sensitive adhesive article of any of claims 1 to 4, wherein the electrically conductive filler comprises conductive carbon black.

6. The pressure sensitive adhesive article of any of claims 1 to 5, wherein the polymeric matrix of the electrically conductive composite layer comprises a poly(mcth)acrylatc, a polyurethane, a polyethylene, a polypropylene, a polyacry lonitrile, a polyimide, a polyvinyl chloride, chlorinated polyolefin, a polystyrene, a polyvinyl butyral, polyvinyl acetate, a polyester, a polyamide, polycarbonate, an alkyd resin, an epoxy resin, a phenolic resin, a natural rubber, a synthetic rubber, a silicone rubber, or combinations thereof.

7. The pressure sensitive adhesive article of any of claims 1 to 6, wherein the second pressure sensitive adhesive layer comprises at least one polymer selected from the group consisting of a (methjacrylic polymer, a rubber-based polymer, a vinyl alkyl ether-based polymer, a silicone- based polymer, a polyester-based polymer, a polyamide-based polymer, a urethane-basedpolymer; and an ionic liquid covalently attached to at least one polymer of the second pressure sensitive adhesive.

8. The pressure sensitive adhesive article of any of claims 1 to 7, wherein the first pressure sensitive adhesive layer is essentially free of a polymerized ionic liquid.

9. The pressure sensitive adhesive article of any of claims 1 to 8, wherein the first pressure sensitive adhesive layer is essentially free of an ionic liquid.

10. The pressure sensitive adhesive article of any of claims 1 to 7, wherein the first pressure sensitive adhesive layer comprises a polymerized ionic liquid.

11. The pressure sensitive adhesive article of any of claims 1 to 10, wherein the first pressure sensitive adhesive layer comprises a different polymer than the second pressure sensitive adhesive layer.

12. The pressure sensitive adhesive article of any of claims 1 to 11, wherein the conductive composite layer exhibits a Young’s modulus of at least 0.

1. 1, 10. 100, 200, or 300 MPa, as determined by Tensile dynamic mechanical analysis or uniaxial tensile testing.

13. The pressure sensitive adhesive article of any of claims 1 to 12, wherein the conductive composite layer is one continuous layer of the electrically conductive filler dispersed in the polymeric matrix.

14. The pressure sensitive adhesive article of any of claims 1 to 13, wherein the first pressure sensitive adhesive layer comprises the same polymer as the second pressure sensitive adhesive layer.

15. The pressure sensitive adhesive article of any of claims 1 to 14, wherein each of the first pressure sensitive adhesive layer and the second pressure sensitive adhesive layer independently has an average thickness of 10 micrometers to 2500 micrometers.

16. The pressure sensitive adhesive article of any of claims 1 to 15, wherein at least one of the first pressure sensitive adhesive layer or the second pressure sensitive adhesive layer has an average thickness of 10 micrometers to 400 micrometers.

17. The pressure sensitive adhesive article of any of claims 1 to 16, wherein the polymerized ionic liquid comprises at least one of a nitrogen-containing ion, a phosphonium ion, a sulfonium ion, an imidazolium ion, a pyridinium ion, or an iodonium ion.

18. The pressure sensitive adhesive article of any of claims 1 to 17, wherein the second pressure sensitive adhesive comprises a polymerized ionic liquid whose ionic liquid precursor comprises an ionic liquid and the polymerizable functional group of the cation of the ionic liquid comprisesat least one of a (meth)acrylate group, a (meth)acrylamide group, a vinyl group, an alcohol group, an epoxy group, a primary or secondary amino group, or a thiol group.

19. The pressure sensitive adhesive article of any of claims 1 to 18. wherein the polymerized ionic liquid comprises at least one of a sulfate, a sulfonate, a carboxylate, a phosphate, a borate, an imide, an imidazole, a bis(sulfonyl)imide. a halide anion, a methide, a nitrate ion, a nitrite ion, a tricyanomethanide, a phosphorus-containing ion. or a dicyanamide.

20. The pressure sensitive adhesive article of any of claims 1 to 19. wherein the second pressure sensitive adhesive comprises a polymerized ionic liquid whose ionic liquid precursor comprises an ionic liquid wherein the polymerizable functional group of the anion of the ionic liquid comprises at least one of a (meth)acrylate group, a (meth)acrylamide group, a vinyl group, an alcohol group, an epoxy group, a primary or secondary amino group, or a thiol group.

21. The pressure sensitive adhesive article of any of claims 1 to 20. wherein an electrical lead is attached to a portion of the electrically conductive composite layer.

22. The pressure sensitive adhesive article of any of claims 1 to 20, wherein the first pressure sensitive adhesive layer is electrically conductive and wherein an electrical lead is attached to a portion of the first pressure sensitive adhesive layer.

23. The pressure sensitive adhesive article of any of claims 1 to 20. wherein at least one of the first pressure sensitive adhesive layer or the second pressure sensitive adhesive layer has at least one discontinuity.

24. The pressure sensitive adhesive article of claim 23. wherein the discontinuity comprises an aperture through either the first pressure sensitive adhesive layer or the second pressure sensitive adhesive layer, wherein the aperture is spaced apart from a perimeter of the first or second pressure sensitive adhesive layer.

25. The pressure sensitive adhesive article of claim 23. wherein the discontinuity comprises a notch through either the first pressure sensitive adhesive layer or the second pressure sensitive adhesive layer, wherein the notch interrupts a perimeter of the first or second pressure sensitive adhesive layer.

26. The pressure sensitive adhesive article of any of claims 23 to 25, wherein an electrical lead is attached to a portion of the electrically conductive composite layer exposed by the at least one discontinuity.

27. The pressure sensitive adhesive article of any of claims 1 to 26, wherein at least one of the first pressure sensitive adhesive or the second pressure sensitive adhesive further comprises an additive comprising at least one of a tackifier, a plasticizer, an adhesion promoter, a stabilizationagent, a corrosion inhibitor, a colorant, an antioxidant, a polymer having a glass transition temperature of at least 40 degrees Celsius, or a filler.

28. The pressure sensitive adhesive article of any of claims 1 to 27. wherein the polymeric matrix of the conductive composite layer comprises a pressure sensitive adhesive.

29. A method of making a bonded article, the method comprising:bonding a pressure sensitive adhesive article to an electrically conductive substrate, the pressure sensitive adhesive article comprising an electrically conductive composite layer having a first major surface and a second major surface, wherein the electrically conductive composite comprises an electrically conductive filler dispersed in a polymeric matrix; a first pressure sensitive adhesive layer disposed on the first major surface of the electrically conductive composite layer; and a second pressure sensitive adhesive layer disposed on the second major surface of the electrically conductive composite layer, wherein the second pressure sensitive adhesive comprises a polymerized ionic liquid; wherein the second pressure sensitive adhesive layer is bonded to the electrically conductive substrate.

30. The method of claim 29, further comprising bonding the first pressure sensitive adhesive layer to an electrically non-conductive substrate.

31. The method of claim 29 or claim 30, wherein the pressure sensitive adhesive article is according to any of claims 2 to 20.

32. A method of debonding a bonded article made by the method of claim 30, the method comprising:applying an electrical potential between the electrically conductive substrate and a portion of the electrically conductive composite; andsubsequently separating the electrically conductive substrate and the electrically non- conductive substrate.

33. The method of debonding a bonded article of claim 32, wherein the pressure sensitive adhesive article is according to any of claims 23 to 26 and the electrical potential is applied to a portion of the electrically conductive composite exposed by the at least one discontinuity.

34. The method of debonding a bonded article of claim 32 or claim 33, wherein the electrically conductive substrate comprises a metal, a mixed metal, an alloy, a metal oxide, a composite metal, a conductive plastic, a conductive polymer, a polymer matrix containing an electrically conductive material dispersed in the matrix, or combinations thereof.

35. A pressure sensitive adhesive article comprising:an electrically conductive first pressure sensitive adhesive layer; anda second pressure sensitive adhesive layer disposed adjacent to the electrically conductive first pressure sensitive adhesive layer, wherein the second pressure sensitive adhesive comprises a polymerized ionic liquid.

36. The pressure sensitive adhesive article of claim 35. wherein the first pressure sensitive adhesive layer comprises an electrically conductive filler dispersed in a pressure sensitive adhesive.

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