Multi-layer pressure-sensitive adhesive assemblies and related methods

Abstract

The multi-layer pressure-sensitive adhesive assembly includes a polymer foam layer and a first pressure-sensitive adhesive layer. The polymer foam includes a plurality of activated carbon particles. The first pressure-sensitive adhesive layer includes a multi-arm block copolymer and at least one hydrocarbon tackifier in an amount greater than 20 weight percent based on the weight of the first pressure-sensitive adhesive layer. The multi-arm block copolymer is represented by the formula Q n -Y, where Q represents an arm of a multi-arm block copolymer, each arm independently has the formula GR, n represents the number of arms and is at least 3, and Y is the residue of a multifunctional coupling agent. Each R is independently a rubbery block comprising a polymerized conjugated diene, a hydrogenated derivative of a polymerized conjugated diene, or a combination thereof, and each G is a glassy block comprising polymerized monovinyl aromatic monomer.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 63 / 253,595, filed October 8, 2021, the disclosure of which is incorporated by reference in its entirety herein. [Background technology]

[0002] Adhesives are used for a variety of marking, holding, protecting, sealing, and shielding purposes. Adhesive tapes generally include a backing or substrate and an adhesive. Pressure-sensitive adhesives are one type of adhesive that is useful for many applications. Pressure-sensitive tapes are found virtually everywhere in the home and workplace. In its simplest structure, pressure-sensitive tape includes an adhesive and a backing, and the overall structure is tacky at the temperature of use and forms a bond using only moderate pressure to adhere to a variety of substrates. In this way, pressure-sensitive tape constitutes a complete, self-contained bonding system.

[0003] Pressure sensitive adhesives (PSAs) are well known to those skilled in the art, and according to the Pressure-Sensitive Tape Council, PSAs are known to have properties including: (1) aggressive and permanent tack, (2) adhesion with finger pressure or less, (3) sufficient ability to stay on the substrate, and (4) sufficient cohesive strength. Materials that have been found to perform well as PSAs include polymers designed and formulated to exhibit the necessary viscoelastic properties that provide the desired balance of tack, peel adhesion, and shear retention. PSAs are typically characterized as being tacky at room temperature (e.g., 20°C). PSAs do not encompass compositions simply because they adhere or bond to a surface. These requirements are generally evaluated by tests designed to measure tack, adhesion (peel strength), and bond (shear retention) separately. This is described in AVPocius in Adhesion and Adhesives Technology: An Introduction, 2nd Ed., Hanser Gardner Publication, Cincinnati, Ohio, 2002. Collectively, these measurements constitute a balance of properties that are often used to characterize PSAs.

[0004] The reduction control of volatile organic compounds (VOCs) has become increasingly important, especially for various interior applications (occupational health and occupational safety), for example in the construction market or in the automotive or electronics industry. Known acrylate-based pressure-sensitive adhesives typically contain significant amounts of low molecular weight organic residues, such as unreacted monomers resulting from the polymerization process, residues of polymerization initiators, impurities from raw materials, or decomposition products formed during the manufacturing process. These low molecular weight residues, recognized as VOCs, can diffuse out of the adhesive tape. Known acrylate-based pressure-sensitive adhesives also generally suffer from a lack of cohesive strength and a tendency to flow excessively when not crosslinked. This aspect can make the applicability and processability of non-crosslinked acrylate-based pressure-sensitive adhesives particularly problematic, especially when made by hot melt processes.

[0005] Reducing the use of organic solvents in the manufacturing process of pressure-sensitive adhesives has been rapidly taken up as one of the straightforward means to reduce the total VOC level. The use of specific scavengers for organic impurities, as described in WO 01 / 44400 (Yang), is another alternative method to achieve reduced VOC levels. However, the solutions known from the prior art to reduce the total VOC level often involve the complexity of the manufacturing process and the increase of production costs.

[0006] Certain pressure sensitive adhesives are described in U.S. Patent Application Publication Nos. 2019 / 0345367 (Eckhardt et al.), 2018 / 0362811 (Waid et al.), 2019 / 0345366 (Eckhardt et al.), 2019 / 0211233 (Bieber et al.), 2010 / 0098962 (Hanley et al.), 2017 / 0313910 (Bieber et al.), and 2014 / 0057091 (Krawinkel et al.), as well as U.S. Patent No. 9,376,599 (Welke et al.). Certain of these pressure sensitive adhesives are described as having reduced VOCs. Summary of the Invention

[0007] According to one embodiment, the present disclosure relates to a multi-layer pressure-sensitive adhesive assembly including a polymer foam layer and a first pressure-sensitive adhesive layer adjacent to the polymer foam layer. The polymer foam includes a plurality of activated carbon particles dispersed therein. The first pressure-sensitive adhesive includes a multi-arm block copolymer and at least one hydrocarbon tackifier in an amount greater than 20 weight percent based on the total weight of the first pressure-sensitive adhesive layer. The multi-arm block copolymer is represented by the formula Q n -Y, where Q represents an arm of a multi-arm block copolymer, each arm independently has the formula GR, n represents the number of arms and is an integer of at least 3, and Y is the residue of a multifunctional coupling agent. Each R is independently a rubbery block comprising a polymerized conjugated diene, a hydrogenated derivative of a polymerized conjugated diene, or a combination thereof, and each G is a glassy block comprising polymerized monovinyl aromatic monomer.

[0008] In another aspect, the present disclosure is directed to a method for making the above multi-layer pressure-sensitive adhesive assembly, comprising blending a multi-arm block copolymer and at least one hydrocarbon tackifier to form a pressure-sensitive adhesive formulation, melt co-extruding a polymer foam layer and a first pressure-sensitive adhesive layer to form a multi-layer pressure-sensitive adhesive assembly, and optionally crosslinking the multi-layer pressure-sensitive adhesive assembly by electron beam irradiation.

[0009] According to yet another aspect, the present disclosure relates to the use of the above-described multi-layer pressure-sensitive adhesive assembly for industrial applications, in some embodiments interior applications, such as construction market applications, automotive applications, or electronics applications.

[0010] In this application, Terms such as "a," "an," and "the" are not intended to refer only to a singular entity, but include the general class of which a specific example may be used for illustrative purposes. The terms "a," "an," and "the" are used interchangeably with the term "at least one."

[0011] The phrase "comprising at least one of" following a list refers to the inclusion of any one of the items in the list, as well as any combination of two or more items in the list. The phrase "at least one of" following a list refers to any one of the items in the list, or any combination of two or more items in the list.

[0012] The terms "crosslinked" and "crosslinkable" refer to the joining of polymer chains together by covalent chemical bonds to form a network polymer. Crosslinked polymers are generally characterized as insoluble, but may be swellable in the presence of an appropriate solvent. The term "crosslinked elastomer" includes partially crosslinked.

[0013] The term "(meth)acrylate" refers to acrylate and / or methacrylate.

[0014] The terms "acrylic" and "polyacrylate" refer to both acrylic and methacrylic polymers, oligomers and monomers.

[0015] All numerical ranges, unless otherwise stated, include the endpoints of those ranges, as well as non-integer values ​​between the endpoints (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] According to a first aspect, the present disclosure relates to a multi-layer pressure-sensitive adhesive assembly including a polymer foam layer and a first pressure-sensitive adhesive layer adjacent to the polymer foam layer, the polymer foam including a plurality of activated carbon particles dispersed therein, and the first pressure-sensitive adhesive including a multi-arm block copolymer and at least one hydrocarbon tackifier in an amount greater than 20 weight percent based on the total weight of the first pressure-sensitive adhesive layer. n-Y, where Q represents an arm of a multi-arm block copolymer, each arm independently having the formula GR, n represents the number of arms and is an integer of at least 3, and Y is a residue of a multifunctional coupling agent. Each R is independently a rubbery block comprising a polymerized conjugated diene, a hydrogenated derivative of a polymerized conjugated diene, or a combination thereof, and each G is a glassy block comprising a polymerized monovinyl aromatic monomer. In the context of the present disclosure, it has been surprisingly found that the multi-layer pressure-sensitive adhesive assemblies of the present disclosure provide outstanding robustness and superior properties and performance in terms of reducing overall VOC levels. These outstanding properties are believed to be at least in part due to the specific combination of the first pressure-sensitive adhesive layer composition described above and the presence of a plurality of activated carbon particles dispersed in the polymer foam layer, which function as an efficient adsorbent for volatile organic compounds from the pressure-sensitive adhesive assembly.

[0017] In some advantageous aspects, the multi-layer pressure-sensitive adhesive assemblies according to the present disclosure are characterized by very low odor or substantially no perceptible odor. In some aspects, the multi-layer pressure-sensitive adhesive assemblies according to the present disclosure are characterized by further providing superior properties and performance with respect to reducing overall fogging levels. The low fogging properties typically translate into improved resistance to condensation of released gas components and corresponding improved thermal stability of the pressure-sensitive adhesive assemblies.

[0018] In addition, the multi-layer pressure-sensitive adhesive assemblies described herein provide a surprisingly good overall balance of adhesive and bonding properties (especially with regard to peel force and static shear resistance) to various types of substrates, including LSE and MSE substrates, in particular automotive clearcoats, plastic substrates such as, for example, TPO, PP, or PP / EPDM, that are commonly used in the automotive industry, automotive varnishes or automotive paints.

[0019] In some advantageous aspects of the present disclosure, according to this aspect, a multi-layer pressure-sensitive adhesive assembly is obtained, for example, by melt co-extrusion, in particular hot melt co-extrusion, of a polymer foam layer and a first pressure-sensitive adhesive layer, and the obtained multi-layer pressure-sensitive adhesive assembly described herein provides excellent resistance to delamination, even at high temperatures, for example, above 70° C. According to the same advantageous aspects, the multi-layer pressure-sensitive adhesive assembly according to the present disclosure advantageously provides excellent surface and interface properties, which is particularly surprising in the practice of foaming the polymer foam layer with expandable microspheres. Without wishing to be bound by theory, it is believed that these remarkable properties are due to the compounds used to form the polymer foam layer and the first pressure-sensitive layer, which are in a molten state at the time the co-extrusion process step is performed. This results in a smooth outer surface of the first pressure-sensitive layer and a smooth interface (without gaps) between the polymer foam layer and the first pressure-sensitive layer. The excellent surface and interface properties of the multi-layer pressure-sensitive adhesive assembly according to the present disclosure can result in good wetting on the substrate to be bonded, thus improving the adhesive properties.

[0020] As such, the multi-layer pressure-sensitive adhesive assemblies according to the present disclosure are particularly suitable for (e.g., industrial) interior applications, more particularly for construction market applications, automotive applications, and electronics applications. In the context of automotive applications, the multi-layer pressure-sensitive adhesive assemblies described herein may find particular use for bonding, for example, automobile body side moldings, weather strips, or rearview mirrors. In some aspects, the multi-layer pressure-sensitive adhesive assemblies according to the present disclosure are provided with advantageous low fogging properties, which are suitable, for example, for electronics applications.

[0021] In the context of this disclosure, the expression "low surface energy substrate" is meant to refer to a substrate having a surface energy of less than 34 dynes per centimeter. Such materials include polypropylene, polyethylene (e.g., High Density Polyethylene (HDPE), Low Density Polyethylene (LDPE), and Linear Low Density Polyethylene (LLDPE)), and blends of polypropylene (e.g., PP / EPDM, TPO).

[0022] In the context of the present disclosure, the expression "medium surface energy substrate" is meant to refer to a substrate having a surface energy in the range of 34 dynes per centimeter to 70 dynes per centimeter, typically 34 dynes per centimeter to 60 dynes per centimeter, and more typically 34 dynes per centimeter to 50 dynes per centimeter. Among such materials are Polyamide 6 (PA6), Acrylonitrile Butadiene Styrene (ABS), Polycarbonate (PC) / ABS blends, PC, PVC, Polyamide (PA), Polyurethane (PUR), Thermoplastic Elastomer (TPE), Polyoxymethylene (POM), Polystyrene, Poly(Methyl Methacrylate) (PMMA), clearcoat surfaces, particularly clearcoats for vehicles such as automobiles or coating surfaces for industrial applications, and composite materials such as fiber reinforced plastics. Surface energy is typically determined from contact angle measurements, for example as described in ASTM D7490-08.

[0023] In typical embodiments, a rubbery block as used herein exhibits a glass transition temperature (Tg) below room temperature. In some embodiments, the Tg of the rubbery block is below about 0° C., or even below about −10° C. In some embodiments, the Tg of the rubbery block is below about −40° C., or even below about −60° C.

[0024] In typical aspects, the glassy blocks used herein exhibit a Tg above room temperature, in some embodiments, the Tg of the glassy blocks is at least about 40°C, at least about 60°C, at least about 80°C, or even at least about 100°C.

[0025] The terms "glass transition temperature" and "Tg" are used interchangeably and refer to the glass transition temperature of a material or mixture. Unless otherwise indicated, glass transition temperature values ​​are determined by Differential Scanning Calorimetry (DSC).

[0026] The multi-layer pressure-sensitive adhesive assembly of the present disclosure comprises a polymer foam layer adjacent to a first pressure-sensitive adhesive layer. Any commonly known polymer foam and material for forming a polymer foam can be used in the context of the present disclosure. In light of the present disclosure, the polymer foam and material suitable for forming the polymer foam used herein can be easily identified by those skilled in the art.

[0027] In the context of the present disclosure, the term "polymer foam" is meant to refer to a polymer-based material that contains voids, typically in an amount of at least 5% by volume, typically 10% to 80% by volume, 10% to 65%, 15% to 45%, or 20% to 45% by volume. The voids can be obtained by any of the known methods, such as bubbles formed by a gas. Alternatively, the voids can result from the incorporation of hollow fillers, such as hollow polymer particles, hollow glass microspheres or hollow ceramic microspheres. According to another alternative embodiment, the voids can result from the incorporation of heat-expandable microspheres, such as pentane-filled expandable microspheres. Heat-expandable microspheres as used herein may expand when the polymer melt passes through an extrusion die. The polymer mixture containing the expandable microspheres may also be extruded at a temperature below their expansion temperature and expanded in a later step by exposing the tape to a temperature above the expansion temperature of the microspheres. Alternatively, the voids can result from the decomposition of a chemical blowing agent. The polymer foam layer typically has a density of 0.30 g / cm 3 ~1.5g / cm 3 , 0.35g / cm 3 ~1.10g / cm 3 , or 0.40 g / cm 3 ~0.95g / cm 3 The density is in the range of

[0028] In some embodiments, the polymer foam layer has viscoelastic properties at room temperature. In some other embodiments, the foam may comprise a thermoplastic foam. In some other embodiments, the foam may comprise a thermosetting foam. Examples of useful foams are also described, for example, in the Handbook of Polymer Foams, David Eaves, editor, published by Shawbury, Shrewsbury, Shropshire, UK: Rapra Technology, 2004.

[0029] According to some aspects of the multi-layer pressure-sensitive adhesive assembly, the polymer foam layer comprises a polymer-based material including at least one of polyacrylate, polyurethane, polyolefin, polyamine, polyamide, polyester, polyether, polyisobutylene, polystyrene, natural rubber, rubber-based elastomeric material, polyvinyl, or polyvinylpyrrolidone, and may include any combination, copolymer, or mixture thereof. In some aspects, the polymer foam layer comprises a polymer-based material including at least one of polyacrylate, polyurethane, or any combination, copolymer, or mixture thereof. In some aspects, the polymer foam layer comprises a polyacrylate, or a mixture of polyacrylates.

[0030] In some embodiments of the multi-layer pressure-sensitive adhesive assembly, the polymer foam comprises a polyacrylate in which the major monomeric component comprises a linear or branched alkyl (meth)acrylic acid ester, e.g., a non-polar linear or branched alkyl (meth)acrylic acid ester having a linear or branched alkyl group having 1 to 32, 1 to 20, or 1 to 15 carbon atoms. Useful linear or branched alkyl (meth)acrylic acid esters include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl (meth)acrylate, n-pentyl (meth)acrylate, iso-pentyl (meth)acrylate, n-hexyl (meth)acrylate, iso-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, phenyl (meth)acrylate. , octyl (meth)acrylate, iso-octyl (meth)acrylate, 2-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, decyl (meth)acrylate, lauryl (meth)acrylate, 2-propylheptyl (meth)acrylate, stearyl (meth)acrylate, isobornyl acrylate, benzyl (meth)acrylate, octadecyl acrylate, nonyl acrylate, dodecyl acrylate, isofolyl (meth)acrylate, and any combination or blend thereof. In some embodiments, the linear or branched alkyl (meth)acrylic acid ester comprises at least one of 2-ethylhexyl (meth)acrylate, iso-octyl (meth)acrylate, 2-propylheptyl (meth)acrylate, butyl acrylate, and any combination or mixture thereof. In some embodiments, the linear or branched alkyl (meth)acrylic ester comprises at least one of 2-ethylhexyl acrylate or iso-octyl acrylate.

[0031] According to an embodiment of the multi-layer pressure-sensitive adhesive assembly, the polymer foam layer comprises a polyacrylate further comprising a comonomer such as acrylic acid, acrylamide, methacrylamide, N,N-dimethylacrylamide, itaconic acid, methacrylic acid, acrylonitrile, methacrylonitrile, vinyl acetate, N-vinylpyrrolidone, isobornyl acrylate, cyanoethyl acrylate, N-vinylcaprolactam, maleic anhydride, hydroxyalkyl acrylates, N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylacrylamide, beta-carboxyethyl acrylate; vinyl esters of neodecanoic acid, neononanoic acid, neopentanoic acid, 2-ethylhexanoic acid, or propionic acid; vinylidene chloride, styrene, vinyl toluene, alkyl vinyl ethers, and any combination or mixture thereof.

[0032] According to another aspect of the multi-layer pressure-sensitive adhesive assembly, the polymer foam layer comprises a polyacrylate that further comprises a polar comonomer, such as a polar acrylate. Suitable comonomers include acrylic acid, methacrylic acid, itaconic acid, hydroxyalkyl acrylates, acrylamides and substituted acrylamides, acrylamines and substituted acrylamines, and any combination or mixture thereof. In some aspects, the polar comonomer is acrylic acid.

[0033] According to the present disclosure, the polymer foam used in the multi-layer pressure-sensitive adhesive assembly includes a plurality of activated carbon particles dispersed therein. Any commonly known activated carbon particles can be used in the context of the present disclosure. Activated carbon particles suitable for use herein can be readily identified by one of ordinary skill in the art in light of the present disclosure.

[0034] In the context of the present disclosure, it has been surprisingly found that the presence of a plurality of activated carbon particles dispersed in a polymer foam layer strongly contributes to the overall reduction of volatile organic compounds emitted from a pressure-sensitive adhesive assembly. It is believed that the plurality of activated carbon particles act as an efficient adsorbent for volatile organic compounds emitted from a pressure-sensitive adhesive assembly. These volatile organic compounds are typically low molecular weight organic residues, such as unreacted monomers resulting from the polymerization process of the polymer foam, residues of polymerization initiators, impurities from raw materials, or decomposition products formed during the manufacture or post-treatment of the pressure-sensitive adhesive assembly. The plurality of activated carbon particles used herein can adsorb volatile organic compounds by chemical adsorption and / or physical adsorption.

[0035] Moreover, it has been found that the activated carbon particles function as a reinforcing material for the polymer foam layer. Moreover, the activated carbon particles may be used as a rheology modifier for the polymer foam layer, which allows fine-tuning of the final desired properties of the resulting multi-layer pressure-sensitive adhesive assembly, particularly its mechanical properties. It has also been found that the activated carbon particles only slightly (and sometimes not at all) affect the elastic properties (particularly Young's modulus) of the polymer foam layer, particularly due to the substantially neutral nature of the particle surface, the relative softness (and brittleness) of the particles, and the limited interaction of the particles with the surrounding polymer. In contrast, the carbon black particles strongly modify the elastic properties of the polymer foam layer, particularly due to the substantially acidic nature of the particle surface, the relative hardness of the carbon black particles, and the strong interaction of the particles with the surrounding polymer.

[0036] In comparison to carbon black particles, activated carbon particles, when used in relatively large amounts, result in the formation of a very black polymer foam layer, which does not adversely affect the properties of the polymer foam layer and the resulting multi-layer pressure-sensitive adhesive assembly, particularly its mechanical properties. In contrast, carbon black particles, when used in relatively large amounts, adversely affect the properties of the polymer foam layer and the resulting multi-layer pressure-sensitive adhesive assembly. Furthermore, the use of activated carbon particles reduces or eliminates the need to apply vacuum degassing operations in an attempt to obtain a multi-layer pressure-sensitive adhesive assembly with reduced VOC level characteristics.

[0037] Activated carbon is carbon that has been processed to be highly porous (i.e., have a large number of pores per unit volume) and therefore have a large surface area. Activated carbon can be produced from a variety of materials, but most commercially available activated carbon is made from peat, coal, lignite, wood, and coconut shells. Based on the source, the carbon may have different pore size, ash content, surface order, and / or impurity profile. Coconut shell-based carbons have a predominantly microporous pore size, while wood-based activated carbons have a predominantly mesoporous or macroporous pore size. Coconut shell- and wood-based carbons typically have an ash content of less than about 3% by weight, while coal-based carbons typically have an ash content of 4% to 10% by weight or even higher.

[0038] Commercially available activated carbon particles include wood-based activated carbon available from Mead Westvaco Corp. (Richmond, VA) under the trade name "NUCHAR RGC", wood-based carbon available from Mead Westvaco Corp. under the trade name "AQUAGUARD", coconut shell-based activated carbon available from Kuraray Chemical Co., Ltd. (Okayama, Japan) under the trade name "KURARAY PGW", and coal-based carbon available from Calgon Carbon Corp. (Pittsburgh, PA) under the trade names "CARBSORB" and "FILTRASORB".

[0039] In some embodiments, the activated carbon particles are dispersed throughout the polymeric foam layer. In some embodiments, the activated carbon particles are substantially uniformly dispersed throughout the cross-section of the polymeric foam layer, meaning that the activated carbon particles are present in about the same concentration (e.g., within 10%) throughout the cross-section of the polymeric foam layer.

[0040] In some embodiments, the activated carbon particles used herein are porous, e.g., have a pore size of 100 m as measured by the BET (Brunauer-Emmett-Teller) nitrogen adsorption test method described in test method ISO 9277:2010. 2 / g~2000m 2 / g, 200m 2 / g~1500m 2 / g, 500m 2 / g~1400m 2 / g, 600m 2 / g~1200m 2 / g, or 700m 2 / g~1000m 2 / g.

[0041] In some embodiments, the activated carbon particles are predominantly microporous, typically having a pore width of 2 nanometers or less, hi some embodiments, at least 75%, at least 80%, at least 85%, at least 90%, or at least 95% of the pores of the activated carbon particles have a pore width of 2 nanometers or less.

[0042] In some embodiments of the multi-layer pressure-sensitive adhesive assemblies of the present disclosure, the amount of activated carbon particles in the polymer foam is at least 0.1 weight percent (wt%), at least 0.5 wt%, at least 1 wt%, at least 3 wt%, at least 5 wt%, or at least 10 wt%, based on the weight of the polymer foam. In some embodiments, the amount of activated carbon particles in the polymer foam is 25 wt% or less, 20 wt% or less, or 15 wt% or less, based on the weight of the polymer foam. In some embodiments, the amount of activated carbon particles in the polymer foam is in the range of 0.1 wt% to 25 wt%, 1 wt% to 20 wt%, 1 wt% to 15 wt%, or 2 wt% to 10 wt%, based on the weight of the polymer foam.

[0043] In some aspects, the polymer foams of the present disclosure may further comprise, as an optional component, a filler material. Such fillers may be advantageously used, for example, to increase the mechanical stability of the polymer foam and may increase its shear resistance and peel force resistance.

[0044] Any filler material generally known to those skilled in the art may be used in the context of the present disclosure.Typical examples of filler materials that can be used herein include expanded perlite, microspheres, expandable microspheres, ceramic spheres, zeolites, clay fillers, glass beads, hollow inorganic beads, silica-based fillers, hydrophobic silica-based fillers, hydrophilic silica-based fillers, fumed silica, fibers (e.g., glass fibers, carbon fibers, graphite fibers, silica fibers, ceramic fibers), electrically conductive and / or thermally conductive particles, nanoparticles (e.g., silica nanoparticles), and any combination thereof.

[0045] In some embodiments, the polymer foam comprises a material selected from the group consisting of microspheres, expandable microspheres, pentane-filled expandable microspheres, gaseous voids, glass beads, glass microspheres, glass bubbles, and any combination or mixture thereof.

[0046] When present, the filler material used herein may be used in the polymer foam in any suitable amount. In some embodiments, the filler material is present in an amount of up to 30 parts by weight, up to 25 parts by weight, or up to 20 parts by weight of the polymer foam. In some embodiments, this amount is typically at least 1 part by weight, or at least 3 parts by weight of the polymer foam. In some embodiments, the filler material is present in an amount ranging from 1 part to 20 parts by weight, from 3 parts to 15 parts by weight, or from 5 parts to 13 parts by weight of the polymer foam. In some embodiments, the filler material is present in an amount ranging from 1 part to 20 parts by weight, from 2 parts to 15 parts by weight, or from 2 parts to 10 parts by weight of the polymer foam.

[0047] The polymer foams used in the present disclosure may further include a crosslinking additive (also referred to as a crosslinking agent and crosslinker) as an optional component. Crosslinking agents can be used to increase the cohesive strength and tensile strength of polymeric materials. Suitable crosslinking additives for use herein can be readily identified by one of ordinary skill in the art in light of the present disclosure. Examples of crosslinking methods include heat, moisture, light sensitivity, actinic radiation or ionizing radiation crosslinking.

[0048] Thermal crosslinkers may optionally be used in combination with suitable accelerators and retarders. Suitable thermal crosslinkers for use herein include isocyanates, particularly trimerized and / or sterically hindered isocyanates that do not contain blocking agents, and epoxide compounds, such as epoxide amine crosslinker systems. Advantageous crosslinking systems and methods are described, for example, in DE 202009013255 (U1) published on March 18, 2010, U.S. Pat. Nos. 5,877,261 (Harder et al.), 7,910,163 (Zollner et al.), 7,935,383 (Zollner et al.), 8,449,962 (Prenzel et al.), 8,802,777 (Zollner et al.), 10,457,791 (Czerwonatis et al.), 9,505,959 (Grittner et al.) and 9,896,605 (Zollner et al.), and U.S. Patent Application Publication No. 2011 / 0274843 (Grittner et al.). Suitable accelerator and retarder systems for use herein are described, for example, in U.S. Pat. No. 9,200,129 (Czerwonatis et al.). Suitable thermal crosslinkers for use herein include epoxycyclohexyl derivatives, in particular epoxycyclohexylcarboxylate derivatives, such as (3,4-epoxycyclohexane)methyl 3,4-epoxycyclohexylcarboxylate, commercially available from Cytec Industries Inc. under the trade name UVACURE 1500. According to a particular embodiment, the polymer foams for use herein may comprise (co)polymers or copolymers crosslinkable with epoxide groups. Correspondingly, at least a portion of the monomers or comonomers used may advantageously be functional monomers crosslinkable with epoxide groups. Monomers having acid groups (especially carboxylic acid groups, sulfonic acid groups or phosphonic acid groups), and / or hydroxyl groups, and / or acid anhydride groups, and / or epoxide groups, and / or amine groups, in particular monomers containing carboxylic acid groups, may be suitably used. Suitable functional monomers are described, for example, in US Pat. No. 9,688,886 (Ring et al.).

[0049] According to another aspect of the disclosure, crosslinking is initiated by ultraviolet light or ionizing radiation such as gamma radiation or electron beam (in the case of ionizing radiation, the use of a separate crosslinking agent is optional).

[0050] Examples of crosslinking additives used herein include compounds having multiple (meth)acryloyl groups, such as di(meth)acrylates, tri(meth)acrylates, tetra(meth)acrylates, penta(meth)acrylates, and combinations thereof. In some embodiments, the multifunctional (meth)acrylate compound has the formula: H2C=C(R 1 )-(CO)-OR 2 -[O-(CO)-(R 1 )C=CH2]n [In the formula, R 1 is hydrogen or methyl, n is 1, 2, 3 or 4, R 2 is alkylene, arylene, heteroalkylene, or any combination thereof. In some embodiments, the crosslinking additive used herein is a multifunctional (meth)acrylate compound selected from the group consisting of 1,6-hexanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, and any combination or mixture thereof.

[0051] Further examples of crosslinking additives for use herein include substituted triazines such as 2,4-bis(trichloromethyl)-6-(4-methoxyphenyl)-s-triazine and 2,4-bis(trichloromethyl)-6-(3,4-dimethoxyphenyl)-s-triazine, as described in U.S. Patents 4,329,384 (Vesley et al.) and 4,330,590 (Vesley). Another class of useful crosslinking additives is copolymerizable monoethylenically unsaturated aromatic ketone comonomers that do not contain ortho-aromatic hydroxyl groups, as disclosed in U.S. Patent 4,737,559 (Kellen et al.). Specific examples include para-acryloxybenzophenone, para-acryloxyethoxybenzophenone, para-N-(methylacryloxyethyl)-carbamoylethoxybenzophenone, para-acryloxyacetophenone, ortho-acrylamidoacetophenone, and acrylated anthraquinone. Yet another suitable crosslinking additive is 1,5-bis(4-benzoylbenzoxy)pentane.Hydrogen abstraction carbonyls, such as anthraquinones, benzophenones and their derivatives, as disclosed in U.S. Patent No. 4,181,752 (Martens et al.), are also suitable.

[0052] When present, the crosslinking additive may be used in an amount of, for example, up to 40% by weight based on the weight of the polymeric foam. In some embodiments, the crosslinking additive may be used in an amount of up to 20%, up to 15%, up to 10%, or up to 5% by weight based on the weight of the polymeric foam. The amount of the crosslinking additive may be, for example, in the range of 0.1% to 10%, 0.5% to 8%, 1% to 6%, or 2% to 5% by weight based on the weight of the polymeric foam. The polymeric foam may also be free of any of the above crosslinking additives.

[0053] In some embodiments of the multi-layer pressure-sensitive adhesive assembly, the polymer foam comprises a) 60% to 100%, 70% to 95%, 80% to 95%, or 85% to 95% by weight, based on the weight of the polymer foam, of free radically polymerizable monomer units, in particular one or more (meth)acrylic acid ester monomers; b) 0% to 40%, 5% to 30%, 5% to 20%, or 5% to 15% by weight, based on the weight of the polymer foam, of comonomer units having ethylenically unsaturated groups, in particular one or more acrylic acid monomers; c) 0% to 20%, 1% to 15%, 2% to 13%, or 2% to 10% by weight of hollow filler particles, in particular hollow filler particles selected from the group consisting of expandable microspheres, pentane-filled expandable microspheres, glass beads, glass microspheres, glass bubbles, and combinations thereof, based on the weight of the polymer foam; Includes.

[0054] According to some aspects of the multi-layer pressure-sensitive adhesive assembly according to the present disclosure, the polymer foam comprises: a) 60% to 100%, 70% to 95%, 80% to 95%, or 85% to 95% by weight, based on the weight of the polymer foam, of one or more (meth)acrylic acid ester monomer units having a linear or branched alkyl group containing 1 to 32, 1 to 20, or 1 to 15 carbon atoms; b) 0% to 40%, 5% to 30%, 5% to 20%, or 5% to 15% by weight, based on the weight of the polymer foam, of one or more acrylic acid monomer units; c) 0% to 20%, 1% to 15%, 2% to 13%, or 2% to 10% by weight of expandable microspheres, such as pentane-filled expandable microspheres, based on the weight of the polymer foam. Includes.

[0055] The polymeric foams and related polymer-based materials used herein can be prepared by any conventional free radical polymerization method generally known to those skilled in the art. Useful methods include solution, radiation, bulk, dispersion, emulsion, solventless and suspension processes.

[0056] In radiation polymerization, the monomer mixture can be irradiated with, for example, ultraviolet (UV) light in the presence of a photopolymerization initiator (ie, photoinitiator). Suitable photoinitiators include those available under the trade name OMNIRAD from IGM Resins (Waalwijk, The Netherlands), including 1-hydroxycyclohexyl phenyl ketone (OMNIRAD 184), 2,2-dimethoxy-1,2-diphenylethan-1-one (OMNIRAD 651), bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (OMNIRAD 819), 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one (OMNIRAD 2959), 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone (OMNIRAD 369), 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one (OMNIRAD 907) and 2-hydroxy-2-methyl-1-phenylpropan-1-one (OMNIRAD 1173), oligo[2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone] available from IGM Resins under the tradename ESACURE KIP 150, and difunctional alpha-hydroxyketones available from IGM Resins under the tradenames ESACURE ONE and ESACURE KIP 160 (2-hydroxy-1-[4-[4-(2-hydroxy-2-methylpropionyl)phenoxy]phenyl]-2-methylpropanone). By difunctional alpha-hydroxyketone it is meant that the photoinitiator contains two alpha-hydroxyketone groups. By multifunctional alpha-hydroxyketone it is meant that the photoinitiator contains more than one alpha-hydroxyketone group. Additional suitable photoinitiators include benzil dimethyl ketal, 2-methyl-2-hydroxypropiophenone, benzoin methyl ether, benzoin isopropyl ether, anisoin methyl ether, aromatic sulfonyl chlorides, photoactive oximes, and combinations thereof.If used, photoinitiators are typically present in an amount of from about 0.01 parts to about 5.0 parts, 0.1 parts to 1 part, or 0.1 parts to 0.5 parts per 100 parts by weight of total monomer.

[0057] In some embodiments, the polymer foam and related polymer-based materials used herein are prepared by a solventless process. Solventless polymerization methods, such as the continuous free radical polymerization methods described in U.S. Patent Nos. 4,619,979 and 4,843,134 (Kotnour et al.), and the method for producing foamed PSA described in U.S. Patent No. 7,879,441 (Gehlsen et al.), can also be used to prepare polymer foam and related polymer-based materials.

[0058] The first pressure-sensitive adhesive in the multi-layer pressure-sensitive adhesive assembly of the present disclosure has the formula Q n -Y A multi-arm block copolymer having wherein Q represents an arm of a multi-arm block copolymer, each arm independently has the formula GR, n represents the number of arms and is an integer of at least 3, Y is a residue of a multifunctional coupling agent, each R is independently a rubbery block comprising a polymerized conjugated diene, a hydrogenated derivative of a polymerized conjugated diene, or a combination thereof, and each G is independently a glassy block comprising a polymerized monovinyl aromatic monomer.

[0059] In some embodiments, n is in the range of 3 to 10, or 3 to 5. In some embodiments, n is at least 4, and in some embodiments, n is at least 6. In some embodiments, the conjugated diene has 4 to 12 carbon atoms. Examples of conjugated dienes include butadiene, isoprene, ethylbutadiene, phenylbutadiene, piperylene, pentadiene, hexadiene, ethylhexadiene, and dimethylbutadiene. The polymerized conjugated dienes may be used individually or as copolymers with each other. In some embodiments, the rubbery block R of at least one arm comprises a polymerized conjugated diene selected from the group consisting of isoprene, butadiene, ethylene butadiene copolymers, hydrogenated derivatives of polyisoprene or polybutadiene, and any combination or mixture thereof. In some embodiments, the rubbery block R of each arm comprises a polymerized conjugated diene selected from the group consisting of isoprene, butadiene, ethylene butadiene copolymers, hydrogenated derivatives of polyisoprene or polybutadiene, and combinations or mixtures thereof. n At least one of the rubbery blocks R of the multi-arm block copolymer having -Y comprises a polymerized conjugated diene selected from the group consisting of isoprene, butadiene, and any combination thereof. In some embodiments, the formula Q n Each of the rubbery blocks R of the multi-arm block copolymer having -Y comprises a polymerized conjugated diene selected from the group consisting of isoprene, butadiene, and any combination thereof. In some embodiments, the formula Q n At least one of the rubbery blocks R or each of the rubbery blocks R of the multi-arm block copolymer having -Y comprises polyisoprene but does not comprise polybutadiene.

[0060] In this specification, the formula Q nThe glassy block G suitable for use in the multi-arm block copolymer having -Y comprises a polymerized monovinyl aromatic monomer. In some embodiments, the monovinyl aromatic monomer has 8 to 18 carbon atoms. Examples of suitable monovinyl aromatic monomers include styrene, vinylpyridine, substituted styrenes (e.g., vinyltoluene, alpha-methylstyrene, methylstyrene, dimethylstyrene, ethylstyrene, diethylstyrene, t-butylstyrene, di-n-butylstyrene, isopropylstyrene and other alkylated styrenes), styrene analogs, and styrene homologs. In some embodiments, the glassy block G of at least one arm comprises a monovinyl aromatic monomer selected from the group consisting of styrene, alkylated styrene, and any combination thereof. According to an advantageous embodiment, the glassy block G of each arm comprises a monovinyl aromatic monomer selected from the group consisting of styrene, styrene compatible blends, and any combination thereof.

[0061] For some embodiments of the multi-layer pressure-sensitive adhesive assemblies according to the present disclosure, the formula Q n At least one arm of the multi-arm block copolymer having -Y is selected from the group consisting of styrene-isoprene-styrene, styrene-butadiene-styrene, styrene-ethylene-butylene-styrene, styrene-ethylene-propylene-styrene, and combinations thereof. n Each arm of the multi-arm block copolymer having -Y is selected from the group consisting of styrene-isoprene-styrene, styrene-butadiene-styrene, styrene-ethylene-butylene-styrene, styrene-ethylene-propylene-styrene, and any combination thereof. n Each arm of the multi-arm block copolymer having -Y is selected from the group consisting of styrene-isoprene-styrene, styrene-butadiene-styrene, and any combination thereof. For some embodiments, the formula Q n At least one or each arm of the multi-arm block copolymer having -Y is a styrene-isoprene-styrene polymer.

[0062] For some embodiments, the formula Q n The multi-arm block copolymer having -Y is a (multi-arm) star block copolymer. For some embodiments, n A multi-arm block copolymer having -Y is a polymodal block copolymer. As used herein, the term "polymodal" means that the copolymer contains end blocks having at least two different molecular weights. Such block copolymers can also be characterized as having at least one "high" molecular weight end block and at least one "low" molecular weight end block, where the terms high and low are used relative to each other. In some particular embodiments, the ratio of the number average molecular weight (Mn)H of the high molecular weight end block to the number average molecular weight (Mn)L of the low molecular weight end block is at least about 1.25.

[0063] In some embodiments, (Mn)H is within the range of about 5,000 to about 50,000. In some embodiments, (Mn)H is at least about 8,000, and in some embodiments, at least about 10,000. In some embodiments, (Mn)H is about 35,000 or less. In some embodiments, (Mn)L is within the range of about 1,000 to about 10,000. In some embodiments, (Mn)L is at least about 2,000, and in some embodiments, at least about 4,000. In some embodiments, (Mn)L is less than about 9,000, and in some embodiments, less than about 8,000.

[0064] According to some embodiments, the formula Q n The multi-arm block copolymer having -Y is an asymmetric block copolymer. In some embodiments, the multi-arm block copolymer is a polymodal asymmetric block copolymer.

[0065] Generally, the polyfunctional coupling agent Y as used herein may be any polyalkenyl coupling agent or other material known to have functional groups capable of reacting with the carbanions of living polymers to form crosslinked polymers. The polyalkenyl coupling agent may be aliphatic, aromatic or heterocyclic. Examples of aliphatic polyalkenyl coupling agents include polyvinyl and polyalkyl acetylenes, diacetylenes, phosphates, phosphites, and dimethacrylates (e.g., ethylene dimethacrylate). Examples of aromatic polyalkenyl coupling agents include polyvinylbenzene, polyvinyltoluene, polyvinylxylene, polyvinylanthracene, polyvinylnaphthalene, and divinyldurene. Examples of polyvinyl groups include divinyl, trivinyl, and tetravinyl groups. In some embodiments, divinylbenzene (Divinylbenzene, DVB) may be used and may include o-divinylbenzene, m-divinylbenzene, p-divinylbenzene, and mixtures thereof. Examples of heterocyclic polyalkenyl coupling agents include divinylpyridine and divinylthiophene. Other examples of polyfunctional coupling agents include silicon halides, polyepoxides, polyisocyanates, polyketones, polyanhydrides, and dicarboxylic acid esters.

[0066] The above formula Q n In some embodiments, the multi-arm block copolymer having the formula Q is present in an amount of greater than 20% by weight based on the total weight of the first pressure-sensitive adhesive layer. n The amount of the multi-arm block copolymer having -Y can be, for example, within the range of 21% to 65% by weight, 25% to 60% by weight, 21% to 40% by weight, or 25% to 35% by weight based on the total weight of the first pressure-sensitive adhesive layer.

[0067] In some embodiments, the first pressure sensitive adhesive layer in the assemblies and methods disclosed herein is represented by the formula L-(G): mwhere L represents a rubbery block, G represents a glassy block, and the number of glassy blocks, m, is 1 or 2. Suitable rubbery blocks, L, include polymerized olefins, polymerized conjugated dienes, hydrogenated derivatives of polymerized conjugated dienes, or any combination thereof.

[0068] In some embodiments, m is 1 and has the formula L-(G): m The linear block copolymer of formula L-(G) is a diblock copolymer comprising one rubbery block M and one glassy block G. In some embodiments, m is 2 and the linear block copolymer comprises two glassy endblocks and one rubbery midblock, i.e., the formula L-(G) m The linear block copolymer of formula L-(G) is a triblock copolymer. In some embodiments, the linear block copolymer of formula L-(G) is a triblock copolymer. m The linear block copolymers include both triblock and diblock copolymers.

[0069] In some embodiments, the rubbery block L comprises a polymerized conjugated diene, a hydrogenated derivative of a polymerized conjugated diene, or any combination thereof. In some embodiments, the conjugated diene has 4 to 12 carbon atoms. Examples of suitable conjugated dienes include butadiene, isoprene, ethylbutadiene, phenylbutadiene, piperylene, pentadiene, hexadiene, ethylhexadiene, and dimethylbutadiene. The polymerized conjugated dienes may be used individually or as copolymers with each other. In some embodiments, the formula L-(G) m The rubbery block L of the linear block copolymer of formula L-(G) comprises a polymerized conjugated diene selected from the group consisting of isoprene, butadiene, and any combination thereof. In some embodiments, the linear block copolymer of formula L-(G) m The rubbery block L of the linear block copolymer of formula (I) comprises polyisoprene but does not comprise polybutadiene. In some embodiments, the rubbery block L comprises a polymerized olefin such as isobutylene.

[0070] In some embodiments, at least one glassy block G comprises a polymerized monovinyl aromatic monomer. In some embodiments, both glassy blocks of the triblock copolymer comprise a polymerized monovinyl aromatic monomer. In some embodiments, the triblock copolymer is represented by the formula L-(G) m The linear block copolymer of comprises two glassy blocks. In some embodiments, the monovinyl aromatic monomer has 8 to 18 carbon atoms. Examples of suitable monovinyl aromatic monomers include styrene, vinylpyridine, substituted styrenes (e.g., vinyltoluene, alpha-methylstyrene, methylstyrene, dimethylstyrene, ethylstyrene, diethylstyrene, t-butylstyrene, di-n-butylstyrene, isopropylstyrene and other alkylated styrenes), styrene analogs, and styrene congeners. In some embodiments, the monovinyl aromatic monomer is selected from the group consisting of styrene, alkylated styrenes, and any combination thereof.

[0071] In some embodiments, the formula L-(G) m The linear block copolymer of formula L-(G) comprises a diblock copolymer. In some embodiments, the diblock copolymer is selected from the group consisting of styrene-isoprene and styrene-butadiene. In some embodiments, the linear block copolymer of formula L-(G) m The linear block copolymers include triblock copolymers. In some embodiments, the triblock copolymer is selected from the group consisting of styrene-isoprene-styrene, styrene-butadiene-styrene, styrene-ethylene-butylene-styrene, styrene-ethylene-propylene-styrene, styrene-isobutylene-styrene, and any combination thereof. Diblock and triblock copolymers are commercially available, for example, under the trade name VECTOR from Dexco Polymer LP (Houston, Texas); and under the trade name KRATON from Kraton Polymers US LLC (Houston, Texas). As manufactured and / or purchased, triblock copolymers may also contain some fraction of diblock copolymer.

[0072] In some embodiments, the compound of formula L-(G) in the first pressure-sensitive adhesive layer m is in the range of 0% to 35%, 5% to 35%, 10% to 35%, or 15% to 30% by weight based on the total weight of the first pressure-sensitive adhesive layer. In some embodiments, the amount of diblock copolymer in which m is 1 in the linear block copolymer is in the range of 0% to 25%, 0% to 20%, 2% to 20%, or 5% to 20% by weight based on the weight of the linear block copolymer.

[0073] In some embodiments, the formula L-(G) m When a linear block copolymer having the formula Q is present in the first pressure-sensitive adhesive layer, n -Y and a multi-arm block copolymer of formula L-(G) m The weight ratio of the linear block copolymer having formula Q to the linear block copolymer having formula Q is in the range of 1:1 to 5:1, 1:1 to 4:1, 1:1 to 3:1, or 1:1 to 2:1. n -Y-bearing multiarm block copolymer and linear block copolymer L-(G) m Such high ratios can provide advantageous adhesion performance of the multi-layer pressure-sensitive adhesive assembly to important substrates, particularly the high temperature shear adhesion performance of the multi-layer pressure-sensitive adhesive assembly. m The presence of may provide various beneficial effects to the (co)polymer precursor of the first pressure-sensitive adhesive and the resulting multi-layer pressure-sensitive adhesive assembly. In particular, the addition of such diblock copolymers may favorably affect the processability of the (co)polymer precursor of the first pressure-sensitive adhesive due to the viscosity-reducing effect (rheology modifier) ​​of this compound. Furthermore, it has been surprisingly found that the diblock copolymers described above, when present in the first pressure-sensitive adhesive, do not unnecessarily migrate to other layers of the multi-layer pressure-sensitive adhesive assembly according to the present disclosure, while still providing a plasticizing effect to the (co)polymer precursor of the first pressure-sensitive adhesive.

[0074] According to the present disclosure, the first pressure-sensitive adhesive layer further comprises at least one hydrocarbon tackifier. Hydrocarbon tackifiers typically included in conventional pressure-sensitive adhesive compositions may be used in the context of the present disclosure. Useful hydrocarbon tackifiers are typically selected to be miscible with the copolymer material and have a VOC value of less than 1000 ppm as measured by thermogravimetric analysis according to the test method described in US Patent Application Publication No. 2019 / 0345367 (Eckhardt et al.), a volatile fogging compounds (FOG) value of less than 1500 ppm as measured by thermogravimetric analysis according to the test method described in US Patent Application Publication No. 2019 / 0345367 (Eckhardt et al.), and / or an outgassing value of less than 1 wt.% as measured by weight loss analysis described in US Patent Application Publication No. 2019 / 0345367 (Eckhardt et al.). Suitable hydrocarbon tackifiers for use herein can be readily identified by those skilled in the art in light of the present disclosure.

[0075] Either solid or liquid hydrocarbon tackifiers may be added. Solid tackifiers generally have a number average molecular weight (M) of 10,000 grams per mole or less. n ), and has a softening point greater than about 70° C. A liquid tackifier is a viscous material having a softening point of from about 0° C. to about 20° C. In some embodiments, the hydrocarbon tackifier is a solid tackifier.

[0076] Suitable hydrocarbon tackifiers include terpene resins, such as polyterpenes (e.g., alpha-pinene-, beta-pinene- and limonene-based resins), and aromatic modified polyterpene resins (e.g., phenol-modified polyterpene resins); coumarone-indene resins; and petroleum-based hydrocarbon resins, such as C5-based hydrocarbon resins, C9-based hydrocarbon resins, C5 / C9-based hydrocarbon resins, and dicyclopentadiene-based resins. Any of these hydrocarbon tackifiers can be partially or fully hydrogenated to improve color, thermal stability, and / or process compatibility. If desired, a combination of various hydrocarbon tackifiers can be used.

[0077] Hydrocarbon resin tackifiers can be prepared from a variety of petroleum-based raw materials. These raw materials can be aliphatic hydrocarbons (mixtures of primarily C5 monomers, such as trans-1,3-pentadiene, cis-1,3-pentadiene, 2-methyl-2-butene, dicyclopentadiene, cyclopentadiene, and cyclopentene, with some other monomers present), aromatic hydrocarbons (mixtures of primarily C9 monomers, such as vinyl toluene, dicyclopentadiene, indene, methylstyrene, styrene, and methylindene, with some other monomers present), or mixtures thereof. Hydrocarbon tackifiers derived from C5 monomers are called C5-based hydrocarbon resins, while those derived from C9 monomers are called C9-based hydrocarbon resins. Some tackifiers are derived from mixtures of C5 and C9 monomers, or are blends of C5 and C9-based hydrocarbon tackifiers. These tackifiers can be called C5 / C9-based hydrocarbon tackifiers.

[0078] C5-based hydrocarbon tackifiers are commercially available from Eastman Chemical Company under the trade names PICCOTAC and EASTOTAC, from Cray Valley under the trade name WING TACK, from Neville Chemical Company under the trade name NEVTAC LX, and from Kolon Industries, Inc. C5-based hydrocarbon tackifiers are commercially available with various degrees of hydrogenation from Eastman Chemical under the trade name EASTOTACK.

[0079] C9-based hydrocarbon tackifiers are commercially available from Eastman Chemical Company under the trade names PICCO, KRISTLEX, PLASTOLYN, and PICCOTAC, and ENDEX, from Cray Valley under the trade name NORSOLENE, from Ruetgers NV under the trade name NOVAREZ, and from Kolon Industries, Inc. under the trade name HIKOTAC. These resins can be partially or fully hydrogenated. Prior to hydrogenation, C9-based hydrocarbon resins are often about 40 percent aromatic as measured by proton nuclear magnetic resonance. Hydrogenated C9-based hydrocarbon resins are commercially available, for example, from Eastman Chemical under the trade names REGALITE and REGALREZ, which are 50 to 100 percent (e.g., 50 percent, 70 percent, 90 percent, and 100 percent) hydrogenated. Partially hydrogenated resins typically have several aromatic rings.

[0080] Various C5 / C9 based hydrocarbon tackifiers are commercially available from Arakawa under the trade name ARKON, from Zeon under the trade name QUINTONE, from Exxon Mobil Chemical under the trade name ESCOREZ, and from Newport Industries under the trade names NURES and H-REZ (Newport Industries). In the context of the present disclosure, suitable hydrocarbon tackifiers for use herein may be advantageously selected from among the C5 / C9 based hydrocarbon tackifiers commercially available from Exxon Mobil Chemical under the trade name ESCOREZ.

[0081] In some aspects of the multi-layer pressure-sensitive adhesive assemblies of the present disclosure, the hydrocarbon tackifier is selected from the group consisting of aliphatic hydrocarbon resins, cycloaliphatic hydrocarbon resins, aromatic modified aliphatic and cycloaliphatic resins, aromatic resins, hydrogenated hydrocarbon resins, terpenes and modified terpene resins, terpene phenolic resins, rosin esters, and any combination or mixture thereof.

[0082] In some embodiments of the present disclosure, the tackifying resin is selected from the group consisting of C5-based hydrocarbon resins, C9-based hydrocarbon resins, C5 / C9-based hydrocarbon resins, and any combination or mixture thereof. In some embodiments, the tackifying resin is selected from the group consisting of hydrogenated terpene resins, hydrogenated rosin resins, hydrogenated C5-based hydrocarbon resins, hydrogenated C9-based hydrocarbon resins, hydrogenated C5 / C9-based hydrocarbon resins, and any combination or mixture thereof.

[0083] In some embodiments, the hydrocarbon tackifier is compatible with at least a portion of the rubbery block R and, optionally, the rubbery block L. In some embodiments, the hydrocarbon tackifier is at least one of the rubbery blocks represented by the formula Q n Each rubbery block R of a multi-arm block copolymer having -Y and optionally the formula L-(G) m The rubbery block L of the linear block copolymer has the formula:

[0084] As used herein, a tackifier is "compatible" with a block if it is miscible with that block. In general, the miscibility of a tackifier with a block can be determined by measuring the effect of the tackifier on the Tg of that block. If a tackifier is miscible with a block, it changes (e.g., increases) the Tg of that block. A tackifier is "compatible" with a block if it is miscible with at least that block, but may also be miscible with other blocks. For example, a tackifier that is compatible with at least a rubbery block will be miscible with the rubbery block, but may also be miscible with a glassy block.

[0085] Examples of hydrocarbon tackifiers compatible with at least the rubbery blocks R and, optionally, the rubbery blocks L are advantageously selected from the group consisting of polymeric terpenes, heterofunctional terpenes, coumarone-indene resins, rosin acids, rosin acid esters, disproportionated rosin acid esters, hydrogenated C5 aliphatic resins, C9 hydrogenated aromatic resins, C5 / C9 aliphatic / aromatic resins, dicyclopentadiene resins, hydrogenated hydrocarbon resins derived from C5 / C9 and dicyclopentadiene precursors, hydrogenated styrene monomer resins, and any blends thereof.

[0086] In the context of this disclosure, it has been found that the addition of a hydrocarbon tackifier that is compatible with at least the rubbery blocks has a beneficial effect on adhesion performance, particularly peel performance.

[0087] In some embodiments, the hydrocarbon tackifier used in the first pressure sensitive adhesive layer has a Tg of at least 60° C., at least 65° C., or even at least 70° C. In some embodiments, the hydrocarbon tackifier has a softening point of at least about 115° C., or at least about 120° C.

[0088] In some embodiments, suitable hydrocarbon tackifiers for use in the first pressure-sensitive adhesive layer are selected from those having a VOC value of less than 1000 ppm, less than 800 ppm, less than 600 ppm, less than 400 ppm, or less than 200 ppm, as measured by thermogravimetric analysis according to the test methods described in U.S. Patent Application Publication No. 2019 / 0345367 (Eckhardt et al.). In some embodiments, the hydrocarbon tackifiers used in the first pressure-sensitive adhesive layer have a FOG value of less than 1500 ppm, less than 1000 ppm, less than 800 ppm, less than 600 ppm, or less than 500 ppm, as measured by thermogravimetric analysis according to the test methods described in U.S. Patent Application Publication No. 2019 / 0345367 (Eckhardt et al.). In some embodiments, the hydrocarbon tackifier used in the first pressure-sensitive adhesive layer has an outgassing value of less than 1 wt%, less than 0.8 wt%, less than 0.6 wt%, less than 0.5 wt%, less than 0.4 wt%, less than 0.3 wt%, less than 0.2 wt%, or less than 0.1 wt%, as measured by weight loss analysis using the oven outgassing test method described in U.S. Patent Application Publication No. 2019 / 0345367 (Eckhardt et al.).

[0089] In some embodiments, the hydrocarbon tackifiers used herein are advantageously selected from the group consisting of coumarone-indene resins, rosin acids, esters of rosin acids, disproportionated rosin acid esters, C9 aromatics, styrene, alpha-methylstyrene, pure monomer resins, and C9 / C5 aromatic modified aliphatic hydrocarbons, and blends thereof.

[0090] In some embodiments of the first pressure-sensitive adhesive layer used in the present disclosure, the ratio of the total weight of all block copolymers to the total weight of all hydrocarbon tackifiers is in the range of 2.4:1 to 1:2.4, 2:1 to 1:2, 1.5:1 to 1:1.5, 1.2:1 to 1:1.2, 1.15:1 to 1:1.15, or 1.1:1 to 1:1.1. In some embodiments of the first pressure-sensitive adhesive layer, the hydrocarbon tackifier can be used in an amount of up to 60 wt% based on the total weight of the first pressure-sensitive adhesive layer. In some embodiments, the hydrocarbon tackifier can be used in an amount of up to 55 wt% or up to 50 wt% based on the total weight of the first pressure-sensitive adhesive layer. The amount of the hydrocarbon tackifier can be, for example, in the range of 35 wt% to 60 wt%, 40 wt% to 60 wt%, or 40 wt% to 55 wt%, based on the total weight of the first pressure-sensitive adhesive layer.

[0091] In some embodiments, the first pressure-sensitive adhesive layer used herein is substantially free of (meth)acrylate copolymers having a Tg of greater than 25° C., 30° C., 40° C., 50° C., 60° C., or 70° C., and a weight average molecular weight (Mw) of 1000 Daltons to 100,000 Daltons as determined by conventional gel permeation chromatography GPC, and comprising one or more (meth)acrylic acid ester monomer units that, when homopolymerized, have a Tg of greater than 25° C., 30° C., 40° C., 50° C., 60° C., or 70° C. When substantially free of such (meth)acrylate copolymers in the first pressure-sensitive adhesive layer, the multilayer pressure-sensitive adhesive assembly may advantageously have a lower odor as measured by VDA270 C3.

[0092] In the context of this disclosure, to determine the Tg of the (meth)acrylate copolymer used herein, a useful predictor Tg of an interpolymer for a particular combination of various monomers is given by the Fox equation: 1 / Tg=ΣW i / Tg i where Tg is the glass transition temperature of the mixture and W i is the weight fraction of component i in the mixture, and Tg iis the glass transition temperature of component i, all glass transition temperatures are in Kelvin (K). Some (meth)acrylic acid ester monomer units in the (meth)acrylate copolymer having a Tg greater than 25° C. are isobornyl (meth)acrylate, tert-butyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, tert-butyl methacrylate, stearyl (meth)acrylate, phenyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, 3,3,5 trimethylcyclohexyl (meth)acrylate, N-octyl (meth)acrylamide, and any combination or mixture thereof. The (meth)acrylate copolymer having a Tg greater than 25° C. may include methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, t-butyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, stearyl (meth)acrylate, phenyl (meth)acrylate, cyclohexyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl acrylate, isobornyl (meth)acrylate, benzyl (meth)acrylate, 3,3,5 trimethylcyclohexyl (meth)acrylate, cyclohexyl (meth)acrylate, N-octylacrylamide, propyl (meth)acrylate. The (meth)acrylate copolymer having a Tg greater than 25° C. may also include at least one of acrylic acid, methacrylic acid, 2-carboxyethyl acrylate, itaconic acid, hydroxyalkyl acrylates, acrylamides and substituted acrylamides (e.g., N,N′ dimethylacrylamide, N,N′ diethylacrylamide), acrylamines and substituted acrylamines, butylcarbamoylethyl acrylate, and any combination or mixture thereof.

[0093] "Substantially free" of (meth)acrylate copolymers having a Tg greater than 25°C and a weight average molecular weight (Mw) of 1000 Daltons to 100,000 Daltons, as described above, refers to less than 3 wt%, 2 wt%, 1 wt%, or 0.5 wt%, including 0 wt%, based on the total weight of the first pressure-sensitive adhesive layer. In some embodiments, the first pressure-sensitive adhesive layer is generally substantially free of (meth)acrylate copolymers, including random or block copolymers.

[0094] In some embodiments, the first pressure sensitive adhesive layer used herein has a weight average molecular weight M of 10,000 g / mol to 100,000 g / mol. w Such polymeric plasticizers may be polyisobutylene, polyisoprene, polybutadiene, amorphous polyolefins and their copolymers, silicones, polyacrylates, oligomeric polyurethanes, ethylene propylene copolymers, and any combinations or mixtures thereof. w "Substantially free" of a polymeric plasticizer having the formula (I) refers to less than 2 wt%, 1 wt%, 0.5 wt%, or 0.1 wt%, including 0 wt%, based on the total weight of the first pressure-sensitive adhesive layer.

[0095] In some embodiments, the first pressure-sensitive adhesive layer useful in the present disclosure may further comprise a filler material as an optional component. The filler material used in the first pressure-sensitive adhesive layer may be any of those described above for use in polymer foams. However, in some embodiments, the first pressure-sensitive adhesive layer does not comprise any of the filler materials selected from the group consisting of microspheres, expandable microspheres (e.g., pentane-filled expandable microspheres), gaseous voids, glass beads, glass microspheres, glass bubbles, and any combination or mixture thereof.

[0096] In some embodiments of the multi-layer pressure-sensitive adhesive assembly according to the present disclosure, the first pressure-sensitive adhesive layer comprises: a multi-arm block copolymer in an amount in the range of 25 weight percent to 60 weight percent based on the total weight of the first pressure-sensitive adhesive layer; a tackifier in an amount of 40 weight percent to 60 weight percent based on the total weight of the first pressure-sensitive adhesive layer; In an amount of from 0 weight percent to 35 weight percent based on the total weight of the first pressure-sensitive adhesive layer, m A linear block copolymer having the formula: Includes.

[0097] In some embodiments, the multi-layer pressure-sensitive adhesive assembly according to the present disclosure is obtained by melt co-extrusion, particularly hot melt co-extrusion, of the polymer foam layer and the first pressure-sensitive adhesive layer. The melt co-extrusion, particularly hot melt co-extrusion, of the polymer foam layer and the first pressure-sensitive adhesive layer can provide outstanding robustness and excellent resistance to delamination even at 70°C and even higher temperatures. Furthermore, the multi-layer pressure-sensitive adhesive assembly obtained by melt co-extrusion, particularly hot melt co-extrusion, of the polymer foam layer and the first pressure-sensitive adhesive layer is less susceptible to unwanted migration of compounds (particularly processing aids or plasticizers) through the layers of the multi-layer pressure-sensitive adhesive assembly according to the present disclosure, mainly because the use of processing aids is not necessary as such when the melt co-extrusion process is carried out.

[0098] The multi-layer pressure-sensitive adhesive assembly of the present disclosure includes a polymer foam layer and the first pressure-sensitive adhesive layer adjacent to the polymer foam layer. The multi-layer pressure-sensitive adhesive assembly according to the present disclosure can have any suitable type of design or configuration depending on its final application and desired properties, provided that it includes the first pressure-sensitive adhesive layer and the polymer foam layer.

[0099] In some embodiments, the multilayer pressure-sensitive adhesive assembly of the present disclosure may take the form of a multilayer structure that includes more overlapping layers, such as a first pressure-sensitive adhesive layer, a polymer foam layer, and adjacent layers, such as additional pressure-sensitive adhesive layers and / or backing layers. Such adhesive multilayer structures or tapes can be advantageously used as two-layer adhesive tapes for adhering two objects together. In that context, suitable polymer foam layers or backing layers used herein may or may not exhibit at least some pressure-sensitive adhesive properties.

[0100] In some aspects, a multi-layer pressure-sensitive adhesive assembly according to the present disclosure includes a polymer foam having a first major surface and a second major surface, and a first pressure-sensitive adhesive layer as described above bonded to the first major surface of the polymer foam layer.

[0101] In some embodiments of the multi-layer pressure-sensitive adhesive assembly, the first pressure-sensitive adhesive layer used herein has a thickness of less than 1500 μm, less than 1000 μm, less than 800 μm, less than 600 μm, less than 400 μm, less than 200 μm, less than 150 μm, or less than 100 μm. In some embodiments, the first pressure-sensitive adhesive layer used herein has a thickness in the range of 20 μm to 1500 μm, 20 μm to 1000 μm, 20 μm to 500 μm, 30 μm to 400 μm, 30 μm to 250 μm, 40 μm to 200 μm, or 50 μm to 150 μm. In some embodiments, the polymer foam layers used herein have a thickness in the range of 100 μm to 6000 μm, 200 μm to 4000 μm, 400 μm to 3000 μm, 500 μm to 2000 μm, or 800 μm to 1500 μm. As will be apparent to one of ordinary skill in the art in light of this description, the thickness of the polymer foam layer will depend on the intended application.

[0102] The thicknesses of the various pressure-sensitive adhesive layers, and other optional layers, in the pressure-sensitive adhesive assembly can vary depending on the desired implementation and associated properties. By way of example, the thickness can be independently selected for each layer within the range of 25 μm to 6000 μm, 40 μm to 3000 μm, 50 μm to 3000 μm, 50 μm to 2000 μm, or 50 μm to 1500 μm.

[0103] In some embodiments, the multi-layer pressure-sensitive adhesive assembly is a skin / core type multi-layer pressure-sensitive adhesive assembly, the polymer foam layer is the core layer of the multi-layer pressure-sensitive adhesive assembly, and the first pressure-sensitive adhesive layer is the skin layer of the multi-layer pressure-sensitive adhesive assembly. The first pressure-sensitive adhesive layer may have a smaller thickness compared to the polymer foam / core layer. For example, the thickness of the pressure-sensitive adhesive layer may be in the range of 20 μm to 250 μm, or 40 μm to 200 μm, while the thickness of the polymer foam layer may be in the range of 100 μm to 6000 μm, 400 μm to 3000 μm, or 800 μm to 2000 μm. Without wishing to be bound by theory, it is believed that the high peel adhesion may be due to the stabilizing effect of the polymer foam layer, which is relatively thick compared to the first pressure-sensitive adhesive layer.

[0104] In some embodiments, the multi-layer pressure-sensitive adhesive assembly further comprises a second pressure-sensitive adhesive skin layer bonded to the second major surface of the polymer foam layer. Such multi-layer pressure-sensitive adhesive assemblies exhibit a three-layer design with the polymer foam layer sandwiched between two pressure-sensitive adhesive layers. This may be considered a skin / core / skin multi-layer assembly. In some embodiments of the multi-layer pressure-sensitive adhesive assembly, the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer are the same adhesive and comprise the pressure-sensitive adhesive composition described above. In some embodiments, the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer each independently comprise the pressure-sensitive adhesive composition described above in any of the embodiments.

[0105] Multi-layer pressure-sensitive adhesive assemblies including polymer foam layers may be advantageous compared to single layer pressure-sensitive adhesives in that the adhesion (instantaneous adhesion) can be tailored by the formulation of the pressure-sensitive adhesive layers (also commonly referred to as skin layers), while other properties / requirements of the overall assembly, such as application issues, deformation issues, and energy dispersion, can be addressed by appropriate formulation of the polymer foam layers (also commonly referred to as core layers).

[0106] In some embodiments of the multi-layer pressure-sensitive adhesive assembly according to the present disclosure, a primer layer may be interposed between the pressure-sensitive adhesive layer and the polymer foam (i.e., core) layer. In the context of the present disclosure, any primer composition generally known to those skilled in the art may be used. Finding a suitable primer composition is well within the capabilities of those skilled in the art in light of the present disclosure. Primers useful for use herein are described, for example, in U.S. Pat. Nos. 5,677,376 (Groves) and 5,605,964 (Groves).

[0107] In some embodiments, the multi-layer pressure-sensitive adhesive assemblies have a VOC value of less than 1500 ppm, less than 1200 ppm, less than 1000 ppm, less than 800 ppm, less than 600 ppm, less than 500 ppm, or even less than 400 ppm as measured by temperature programmed desorption analysis according to test method VDA278 (Thermal Desorption Analysis of Organic Emissions for the Characterization of Non-Metallic Materials for Automobiles) of the VDA, Association of the German Automobile Industry.

[0108] In some embodiments, the multi-layer pressure-sensitive adhesive assembly has a FOG value of less than 4000 ppm, less than 3000 ppm, less than 2500 ppm, less than 2000 ppm, less than 1500 ppm, less than 1000 ppm, less than 800 ppm, or even less than 600 ppm as measured by temperature programmed desorption analysis according to test method VDA278.

[0109] In some embodiments, the multi-layer pressure-sensitive adhesive assembly has a static shear strength value of greater than 300 minutes, greater than 500 minutes, greater than 1000 minutes, greater than 2000 minutes, greater than 4000 minutes, greater than 5000 minutes, greater than 6000 minutes, greater than 8000 minutes, or greater than 10000 minutes, when measured at 70°C (500g on stainless steel) by the Static Shear Test Method described in the Experimental Section.

[0110] In some embodiments, the multi-layer pressure-sensitive adhesive assembly has a static shear strength value of greater than 300 minutes, greater than 500 minutes, greater than 1000 minutes, greater than 2000 minutes, greater than 4000 minutes, greater than 5000 minutes, greater than 6000 minutes, greater than 8000 minutes, or greater than 10000 minutes, as measured at 90°C (500g on stainless steel) by the Static Shear Test Method described in the Experimental Section.

[0111] In some embodiments, the multi-layer pressure-sensitive adhesive assembly has a peel strength value of greater than 30 N, greater than 35 N, greater than 40 N, greater than 45 N, or greater than 50 N per 10 mm when measured at 23° C. on stainless steel using the peel test method described in the Experimental Section.

[0112] In some embodiments, the multi-layer pressure-sensitive adhesive assembly has a peel strength value of greater than 30 N, greater than 35 N, greater than 40 N, or greater than 45 N per 10 mm when measured at 23° C. on polypropylene using the peel test method described in the Experimental Section.

[0113] In some embodiments, the multi-layer pressure-sensitive adhesive assembly has an odor level of 4 or less, or 3 or less according to VDA270 C3.

[0114] Melt coextrusion, particularly hot melt coextrusion, is a technique well known to those skilled in the art. Examples of hot melt coextrusion processes are described, for example, in U.S. Patent Application Publication Nos. 2003 / 0082362(A1) (Khandpur et al.) and 2004 / 0082700(A1) (Khandpur et al.). Hot melt coextrusion typically involves forming a polymer or blended polymer material with a melt viscosity profile that allows hot melt compositions to be extrusion coated in a thin layer onto a substrate or carrier, typically at processing temperatures significantly above normal room temperature, but still retain useful pressure-sensitive adhesive properties at room temperature.

[0115] The multi-layer pressure-sensitive adhesive assemblies of the present disclosure may be produced by hot-melt co-extrusion of a polymer foam layer, a first pressure-sensitive adhesive layer, and optionally a second pressure-sensitive adhesive layer. A useful process may include compounding the various components of each layer (e.g., block copolymer and hydrocarbon tackifier) ​​into a hot-melt compound. Compounding can be carried out in a roll mill or extruder (e.g., single screw, twin screw, planetary, ring, disc screw, reciprocating single screw, and pin barrel single screw extruders). Commercially available equipment such as kneaders or mixers may be used to compound batches of pressure-sensitive adhesive and polymer foam compositions. After compounding, the various prepared compositions are co-extruded through a co-extrusion die into the desired multi-layer assembly. Processing of the multi-layer extrudate continues through a calendar or another type of coating equipment. Due to at least the adhesive behavior of the pressure-sensitive adhesive composition, the composition is coated onto a liner and the roll is coated with a material that does not adhere to the extruded adhesive.

[0116] In some embodiments, the multi-layer pressure-sensitive adhesive assembly according to the present disclosure is crosslinked with actinic radiation, such as, for example, E-beam radiation. In some embodiments, the multi-layer pressure-sensitive adhesive assembly is crosslinked with E-beam radiation, and the E-beam radiation dose is in the range of 50 kGy to 150 kGy. In some embodiments, the E-beam radiation is performed from both sides to achieve a symmetrical radiation profile in the multi-layer pressure-sensitive adhesive assembly. The process of crosslinking the multi-layer pressure-sensitive adhesive assembly described above, particularly with actinic radiation, for example, E-beam radiation, can provide a multi-layer pressure-sensitive adhesive assembly characterized by excellent static shear performance at both room temperature and elevated temperatures (e.g., 70°C).

[0117] During E-beam radiation-based crosslinking, finding a suitable E-beam radiation dose in conjunction with selecting a suitable E-beam acceleration voltage is well within the scope of practice for those skilled in the art. The suitable acceleration voltage is typically selected and adapted to the coating weight of the corresponding multi-layer pressure-sensitive adhesive assembly. The E-beam acceleration voltage is typically selected at a coating weight of 25 g / m 2 ~1200g / m 2For pressure-sensitive adhesive layers with coating weights in the range of 140 kV to 300 kV. When irradiated from both sides, the pressure-sensitive adhesive layer can reach up to 1800 g / m 2 The coating weight may be

[0118] The actinic radiation crosslinking process can be applied under closed face (CF) or open face (OF) conditions. According to the "closed face" irradiation method, one or both sides of the hot melt coextruded multi-layer pressure-sensitive adhesive assembly are covered with a liner and the radiation dose is applied through the liner. According to the "open face" irradiation method, one or both sides of the hot melt coextruded multi-layer pressure-sensitive adhesive assembly are exposed (i.e., not covered with a liner) and the radiation dose is applied directly to the exposed adhesive surfaces.

[0119] Typically, a hot melt coextruded multi-layer pressure sensitive adhesive assembly is deposited onto a substrate and then crosslinked with actinic radiation, for example E-beam radiation.

[0120] Another aspect of the present disclosure provides a method for producing the above-described multi-layer pressure-sensitive adhesive assembly, comprising melt co-extruding, in particular hot melt co-extruding, a polymer foam layer, a first pressure-sensitive adhesive layer, and optionally a second pressure-sensitive adhesive layer.

[0121] In some aspects, the present disclosure is directed to a method for producing the above multi-layer pressure-sensitive adhesive assembly, comprising blending a multi-arm block copolymer with at least one hydrocarbon tackifier to form a pressure-sensitive adhesive formulation, melt co-extruding a polymer foam layer and the pressure-sensitive adhesive formulation to form a multi-layer pressure-sensitive adhesive assembly, and optionally crosslinking the multi-layer pressure-sensitive adhesive assembly by electron beam irradiation.

[0122] According to some aspects of the method for making a multi-layer pressure-sensitive adhesive assembly, the hot melt of the polymer foam layer includes a filler material selected from the group consisting of expandable microspheres, expanded microspheres, glass bubbles, any combination or mixture thereof. According to this aspect, the method for making a multi-layer pressure-sensitive adhesive assembly may optionally include a step of expanding or further expanding the expandable microspheres.

[0123] In some aspects, the method for producing the multi-layer pressure-sensitive adhesive assembly comprises an extrusion process selected from the group consisting of multi-screw extrusion, planetary extrusion, and any combination thereof. According to some aspects, the method for producing the multi-layer pressure-sensitive adhesive assembly comprises a twin-screw hot melt extrusion process.

[0124] According to some embodiments of the method for producing a multi-layer pressure-sensitive adhesive assembly, the hydrocarbon tackifier is exposed to minimal thermal stress before being delivered into the formulation medium. In the context of the present disclosure, it has been found in practice that high temperature thermal stress applied to the hydrocarbon tackifier for extended periods of time can accelerate the thermal and / or oxidative decomposition of these components and cause the generation of VOCs.

[0125] Thus, in some aspects of the method for producing a multi-layer pressure-sensitive adhesive assembly, the hydrocarbon tackifier is added to the formulation medium using a drum unloader as a feed device. In some aspects, the hydrocarbon tackifier is fed to the formulation medium using a single screw feed extruder. In some aspects, the hydrocarbon tackifier is fed to the formulation medium using a kneading device having a discharge screw. In some aspects, the hydrocarbon tackifier is added to the formulation medium in a solid state by a volumetric or gravimetric feeder.

[0126] In some embodiments, the method for producing a multi-layer pressure-sensitive adhesive assembly includes applying a vacuum degassing operation, such as a multi-stage vacuum degassing operation, of at least one of the hot melt compounds. The vacuum can typically be applied to the formulated adhesive melt during the extrusion process. The vacuum can be applied to the skin formulation melt and / or the core formulation melt before adding the blowing agent.

[0127] According to some embodiments, a method for producing a multi-layer pressure-sensitive adhesive assembly includes incorporating a VOC-entraining additive into at least one of the hot melt compounds, the VOC-entraining additive being advantageously selected from the group consisting of water, carbon dioxide, nitrogen gas, and any combination thereof.

[0128] According to some embodiments of the method for producing a multi-layer pressure-sensitive adhesive assembly, a chemical entraining agent is added to the formulated adhesive melt and subsequently removed in the extrusion process. Suitable entraining agents for use herein are liquids, gases or compounds that release volatile chemicals under the action of heat. Advantageously, the entraining agent can entrain further volatiles or last traces of volatiles. Suitable entraining agents can be added to the skin PSA melt and / or to the core melt and subsequently removed in the extrusion process. If an entraining agent is added to the core compound, the entraining agent is desirably removed before adding the blowing agent. One particularly suitable entraining additive for use herein is described in EP 2808371(A1) (Buettner et al.).

[0129] In the context of manufacturing a multi-layer pressure-sensitive adhesive assembly, the various layers of the multi-layer pressure-sensitive adhesive assembly can be prepared as part of a single process step.

[0130] The multi-layer pressure-sensitive adhesive assemblies of the present disclosure can be coated / applied onto a variety of substrates to produce adhesive-coated articles. The substrates can be flexible or non-flexible and can be formed from polymeric materials, paper, glass or ceramic materials, metals, or combinations thereof. Suitable polymeric substrates include polymeric films such as those prepared from polypropylene, polyethylene, polyvinyl chloride, polyester (polyethylene terephthalate or polyethylene naphthalate), polycarbonate, polyurethane, polymethyl (meth)acrylate (PMMA), polyurethane acrylate, cellulose acetate, cellulose triacetate, ethyl cellulose, nonwoven materials (e.g., paper, cloth, nonwoven scrims), and metal foils. Foam backings may also be used. Examples of other substrates include metals such as stainless steel, polymeric materials coated with metals or metal oxides, and glass coated with metals or metal oxides.

[0131] The multi-layer pressure-sensitive adhesive assembly of the present disclosure may be used on any conventionally known article, such as labels, tapes, signs, covers, marking indicia, display components, and touch panels. Flexible backing materials with high-definition surfaces are also contemplated. The substrate to which the multi-layer pressure-sensitive adhesive assembly can be applied is selected according to the specific application. For example, the multi-layer pressure-sensitive adhesive assembly may be applied to sheet products (e.g., decorative graphics and reflective products), label stock, and tape backing. In addition, the multi-layer pressure-sensitive adhesive assembly may be applied directly onto other substrates, such as metal panels (e.g., automobile panels) or glass windows, so that further substrates or objects can be attached to the panel or window. Thus, the multi-layer pressure-sensitive adhesive assembly of the present disclosure may find particular use in the automotive manufacturing industry (e.g., for attaching exterior trim parts or weather strips), the construction industry, the solar panel construction industry, and the electronics industry (e.g., for fastening displays in mobile handheld devices).

[0132] As can be seen, the multi-layer pressure-sensitive adhesive assemblies according to the present disclosure are particularly suitable for (industrial) interior applications, more particularly for construction market applications, automotive applications, and electronics applications. In the context of automotive applications, the multi-layer pressure-sensitive adhesive assemblies described herein may find particular use, for example, for bonding automobile body side moldings, weather strips, and rearview mirrors. The multi-layer pressure-sensitive adhesive assemblies according to the present disclosure are particularly suitable for bonding to substrates / panels painted with automotive paint systems including electrocoat or pigmented basecoats, in particular for bonding to clearcoat surfaces, in particular clearcoats for motor vehicles. The multi-layer pressure-sensitive adhesive assemblies according to the present disclosure are particularly suitable for bonding to low energy surfaces such as polypropylene, polyethylene, or copolymers thereof.

[0133] Accordingly, the present disclosure is further directed to the use of the above-described multi-layer pressure-sensitive adhesive assemblies for industrial applications, such as interior (industrial) applications, construction market applications, automotive applications, and / or electronics applications.

[0134] In another aspect, the present disclosure is further directed to the use of the above multi-layer pressure-sensitive adhesive assembly for automotive applications, particularly for taped seals on bodies, taped seals on doors, exterior and interior part attachment and weather strip tape applications for the automotive industry. In some aspects, the multi-layer pressure-sensitive adhesive assembly has a value below the threshold value according to the JAMA:Jaso M902 test method.

[0135] In some embodiments, the multi-layer pressure-sensitive adhesive assemblies according to the present disclosure may be particularly useful for forming strong adhesive bonds to low surface energy (LSE) substrates. However, the use of these multi-layer pressure-sensitive adhesive assemblies is not limited to low surface energy substrates. The multi-layer pressure-sensitive adhesive assemblies may, in some embodiments, surprisingly bond well to medium surface energy (MSE) substrates. Included among such materials are PA6, ABS, PC / ABS blends, PC, PVC, PA, PUR, TPE, POM, polystyrene, poly(methyl methacrylate) (PMMA), clearcoat surfaces, particularly clearcoats for vehicles such as automobiles or coating surfaces for industrial applications, and composite materials such as fiber-reinforced plastics.

[0136] Thus, the present disclosure is further directed in some aspects to the use of the above-described multi-layer pressure-sensitive adhesive assemblies for bonding to low and / or medium surface energy substrates.

[0137] The multi-layer pressure-sensitive adhesive assembly can also be provided as a single- or double-coated tape, in which the multi-layer pressure-sensitive adhesive assembly is disposed on a permanent backing. The backing can be made of plastic (e.g., polypropylene, including biaxially oriented polypropylene, vinyl, polyolefins (polyethylene, polyurethane, polyurethane acrylate, etc.), polyesters (polyethylene terephthalate, etc.)), nonwoven materials (e.g., paper, cloth, nonwoven scrims), metal foils, and foams (e.g., polyacrylics, polyethylene, polyurethane, neoprene). Polymer foams are commercially available from 3M Co., Voltek, Sekisui, and a variety of other sources.

[0138] Item 1 is a multi-layer pressure-sensitive adhesive assembly including a polymeric foam layer and a first pressure-sensitive adhesive layer adjacent to the polymeric foam layer, the polymeric foam including a plurality of activated carbon particles dispersed therein, the first pressure-sensitive adhesive comprising: In an amount greater than 20 weight percent based on the total weight of the first pressure-sensitive adhesive layer, n -Y A multi-arm block copolymer having: [In the formula, Q represents an arm of a multi-arm block copolymer, each arm independently having the formula GR; n represents the number of arms and is an integer of at least 3; Y is a residue of a multifunctional coupling agent; each R is a rubbery block comprising a polymerized conjugated diene, a hydrogenated derivative of a polymerized conjugated diene, or a combination thereof, and each G is a glassy block comprising a polymerized monovinyl aromatic monomer; At least one hydrocarbon tackifier; A multi-layer pressure-sensitive adhesive assembly comprising:

[0139] Item 2 is the maximum permeability of activated carbon particles measured by the BET nitrogen adsorption test method at 100 m 2 / g~2000m 2 / g, 200m 2 / g~1500m 2 / g, 500m 2 / g~1400m 2 / g, 600m 2 / g~1200m 2 / g, or 700m 2 / g~1000m 2 2. The multi-layer pressure-sensitive adhesive assembly according to item 1, having individual specific surface areas in the range of 1 / g.

[0140] Item 3 is the multi-layer pressure-sensitive adhesive assembly of items 1 or 2, wherein at least 75%, at least 80%, at least 85%, at least 90%, or at least 95% of the pores of the activated carbon particles have a pore width of 2 nanometers or less.

[0141] Item 4 is the multi-layer pressure-sensitive adhesive assembly of any one of items 1-3, wherein the amount of activated carbon particles in the polymer foam is at least 0.1 wt.%, at least 1 wt.%, at least 3 wt.%, at least 5 wt.%, or even at least 10 wt.%, based on the weight of the polymer foam.

[0142] Item 5 is the multi-layer pressure-sensitive adhesive assembly of any one of items 1 to 4, wherein the amount of activated carbon particles in the polymer foam is 25% by weight or less, 20% by weight or less, or 15% by weight or less, based on the weight of the polymer foam.

[0143] Item 6 is the multi-layer pressure-sensitive adhesive assembly of any one of items 1 to 5, wherein the activated carbon particles are present in the polymer foam in an amount in the range of 0.1 weight percent to 15 weight percent, based on the total weight of the polymer foam.

[0144] Item 7 is the multi-layer pressure-sensitive adhesive assembly of any one of items 1 to 6, wherein the polymer foam comprises a polymer-based material including at least one of polyacrylate, polyurethane, polyolefin, polyamine, polyamide, polyester, polyether, polyisobutylene, polystyrene, natural rubber, rubber-based elastomeric material, polyvinyl, or polyvinylpyrrolidone.

[0145] Item 8 is the multi-layer pressure-sensitive adhesive assembly of any one of items 1 to 7, wherein the polymer foam comprises a polymeric material selected from the group consisting of polyacrylates whose major monomeric component comprises linear or branched alkyl (meth)acrylic esters containing 1 to 32, 1 to 20, or 1 to 15 carbon atoms.

[0146] Item 9 is the multi-layer pressure-sensitive adhesive assembly of item 8, wherein the polymeric material further comprises a comonomer selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid, hydroxyalkyl acrylates, acrylamides and substituted acrylamides, acrylamines and substituted acrylamines, and any combination or mixture thereof.

[0147] Item 10 is a method for producing a polymer foam comprising the steps of: a) 60% to 100%, 70% to 95%, 80% to 95%, or 85% to 95% by weight, based on the weight of the polymer foam, of monomer units of at least one (meth)acrylic acid ester having a linear or branched alkyl group having 1 to 32, 1 to 20, or 1 to 15 carbon atoms; b) 0% to 40%, 5% to 30%, 5% to 20%, or 5% to 15% by weight of acrylic acid monomer units, based on the weight of the polymer foam; c) 0% to 20%, 1% to 15%, 2% to 13%, or 2% to 10% by weight of expandable microspheres, such as pentane-filled expandable microspheres, based on the weight of the polymer foam. 10. The multi-layer pressure-sensitive adhesive assembly of claim 8 or 9, comprising:

[0148] Item 11 is a method for producing a polymer foam comprising the steps of: a) 60% to 100%, 70% to 95%, 80% to 95%, or 85% to 95% by weight, based on the weight of the polyacrylate, of at least one (meth)acrylic acid ester monomer having a linear or branched alkyl group having 1 to 32, 1 to 20, or 1 to 15 carbon atoms; b) 0% to 40%, 5% to 30%, 5% to 20%, or 5% to 15% by weight of an acrylic acid monomer, based on the weight of the polyacrylate; c) 0.01 parts to about 5.0 parts, 0.1 parts to 1.0 parts, or 0.1 parts to 0.5 parts of a multifunctional alpha-hydroxyketone photoinitiator per 100 parts by weight of total monomer; 11. The multi-layer pressure-sensitive adhesive assembly of any one of items 1 to 10, comprising a polyacrylic material prepared by irradiating a composition comprising:

[0149] Item 12 is the formula Q n12. The multi-arm block copolymer of claim 1, wherein the -Y multi-arm block copolymer is a star block copolymer.

[0150] Item 13 is the multi-layer pressure-sensitive adhesive assembly of any one of items 1-12, wherein the polymerized conjugated diene comprises at least one of polyisoprene or polybutadiene, or R further comprises polyisobutylene.

[0151] Item 14 is the formula Q n For at least one of the rubbery blocks R of the multi-arm block copolymer having -Y, The polymerized conjugated diene comprises at least one of isoprene or butadiene, or has the formula Q n 14. The multi-layer pressure-sensitive adhesive assembly of any one of the preceding claims, wherein for each of the rubbery blocks R of the multi-arm block copolymer having -Y, the polymerized conjugated diene comprises at least one of isoprene or butadiene.

[0152] Item 15 is the formula Q n At least one of the glassy blocks of the multi-arm block copolymer having -Y is a polymerized monovinyl aromatic monomer comprising at least one of styrene or alkylated styrene, or a monomer represented by the formula Q n 15. The multi-layer pressure-sensitive adhesive assembly of any one of the preceding claims, wherein each of the glassy blocks of the multi-arm block copolymer having -Y is a polymerized monovinyl aromatic monomer comprising at least one of styrene or alkylated styrene.

[0153] Item 16 is the formula Q n -Y, or at least one arm of a multi-arm block copolymer having the formula Q n16. The multi-layer pressure-sensitive adhesive assembly of any one of the preceding claims, wherein at least each arm of the multi-arm block copolymer having -Y is selected from the group consisting of styrene-isoprene-styrene, styrene-butadiene-styrene, styrene-ethylene-butylene-styrene, styrene-ethylene-propylene-styrene, and combinations thereof.

[0154] Item 17 is the formula Q n 17. The multi-layer pressure-sensitive adhesive assembly according to any one of items 1 to 16, wherein the number of arms, n, of the multi-arm block copolymer having -Y is an integer from 3 to 5.

[0155] Item 18 is the first pressure-sensitive adhesive layer comprising: a multi-arm block copolymer in an amount in the range of 25 weight percent to 60 weight percent based on the total weight of the first pressure-sensitive adhesive layer; a tackifier in an amount of 40 weight percent to 60 weight percent based on the total weight of the first pressure-sensitive adhesive layer; In an amount of from 0 weight percent to 35 weight percent based on the total weight of the first pressure-sensitive adhesive layer, m A linear block copolymer having the formula: [In the formula, L is a rubbery block comprising a polymerized olefin, a polymerized conjugated diene, a hydrogenated derivative of a polymerized conjugated diene, or any combination thereof; G is a glassy block comprising polymerized monovinyl aromatic monomers, and m is 1 or 2; 18. The multi-layer pressure-sensitive adhesive assembly according to any one of items 1 to 17, comprising:

[0156] Item 19 is the formula L-(G) m Item 19. The multi-layer pressure-sensitive adhesive assembly according to item 18, wherein the rubbery block L of the linear block copolymer having the formula

[0157] Item 20 is the formula L-(G) m20. The multilayer pressure-sensitive adhesive assembly of claim 18 or 19, wherein at least one of the glassy blocks G of the linear block copolymer having the formula

[0158] Item 21 is the formula L-(G) m 21. The multilayer pressure-sensitive adhesive assembly of any one of items 18 to 20, wherein the linear block copolymer having the formula

[0159] Item 22 is the multi-layer pressure-sensitive adhesive assembly of any one of items 18 to 21, wherein the weight ratio of the multi-arm block copolymer to the linear block copolymer in the first pressure-sensitive adhesive is within the range of 1:1 to 5:1.

[0160] Item 23 is the multilayer pressure-sensitive adhesive assembly of any one of items 1 to 22, wherein the hydrocarbon tackifier has a Tg of at least 60°C, or at least 65°C, and the hydrocarbon tackifier is compatible with at least the rubbery block R, and optionally with the rubbery block L.

[0161] Item 24 is the multilayer pressure-sensitive adhesive assembly of any one of items 1 to 23, wherein the hydrocarbon tackifier is selected from the group consisting of coumarone-indene resins, rosin acids, esters of rosin acids, disproportionated rosin acid esters, C9 aromatics, styrene, alpha-methylstyrene, pure monomer resins, and C9 / C5 aromatic modified aliphatic hydrocarbons, and blends thereof.

[0162] Item 25 is the multi-layer pressure-sensitive adhesive assembly of any one of items 1 to 24, wherein the hydrocarbon tackifier has a volatile organic compound (VOC) value, as measured by thermogravimetric analysis, of less than 800 ppm, less than 600 ppm, less than 400 ppm, or less than 200 ppm.

[0163] Item 26 is the multi-layer adhesive assembly of any one of items 1 to 25, wherein the hydrocarbon tackifier has a volatile fogging compounds (FOG) value, as measured by thermogravimetric analysis, of less than 1500 ppm, less than 1000 ppm, less than 800 ppm, less than 600 ppm, or less than 500 ppm.

[0164] Item 27 is the multilayer pressure-sensitive adhesive assembly of any one of items 1 to 26, wherein the hydrocarbon tackifier has an outgassing value of less than 1 wt%, less than 0.8 wt%, less than 0.6 wt%, less than 0.5 wt%, less than 0.4 wt%, less than 0.3 wt%, less than 0.2 wt%, or less than 0.1 wt%, as measured by weight loss analysis according to the oven outgassing test method described in U.S. Patent Application Publication No. 2019 / 0345367.

[0165] Item 28 is the multilayer pressure-sensitive adhesive assembly of any one of items 1 to 27, wherein the ratio of the total weight of all block copolymers to the total weight of all hydrocarbon tackifiers in the first pressure-sensitive adhesive is within the range of 2.4:1 to 1:2.4, 2:1 to 1:2, 1.5:1 to 1:1.5, 1.2:1 to 1:1.2, 1.15:1 to 1:1.15, or 1.1:1 to 1:1.1.

[0166] Item 29 is the multilayer pressure-sensitive adhesive assembly of any one of items 1 to 28, wherein the first pressure-sensitive adhesive layer has a Tg greater than 25° C., a weight average molecular weight (Mw) of 1000 grams / mole to 100,000 grams / mole, and is substantially free of (meth)acrylate copolymers comprising (meth)acrylic acid ester monomer units that, when homopolymerized, have a Tg greater than 25° C.

[0167] Item 30 is the multi-layer pressure-sensitive adhesive assembly of any one of items 1 to 29, wherein the first pressure-sensitive adhesive layer is substantially free of (meth)acrylate copolymer.

[0168] Item 31 is a method for preparing a pressure-sensitive adhesive layer having a weight average molecular weight M of at least 10,000 grams / mole. w 31. The multi-layer pressure-sensitive adhesive assembly of any one of the preceding items, wherein the multi-layer pressure-sensitive adhesive assembly is substantially free of a polymeric plasticizer having the formula:

[0169] Item 32 is a multilayer pressure-sensitive adhesive assembly according to any one of items 1 to 31, obtained by melt coextrusion, in particular hot melt coextrusion, of a polymer foam layer and a first pressure-sensitive adhesive layer.

[0170] Item 33 is the multi-layer pressure-sensitive adhesive assembly of any one of items 1 to 32, crosslinked by actinic radiation or by E-beam irradiation.

[0171] Item 34 is the multi-layer pressure-sensitive adhesive assembly of any one of items 1 to 33, wherein the polymer foam layer has a first major surface and a second major surface, the first pressure-sensitive adhesive layer is bonded to the first major surface of the polymer foam layer, and the multi-layer pressure-sensitive adhesive assembly further includes a second pressure-sensitive adhesive layer bonded to the second major surface of the polymer foam layer.

[0172] Item 35 is the multi-layer pressure-sensitive adhesive assembly of item 34, wherein the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer have the same pressure-sensitive adhesive composition.

[0173] Item 36 is the multi-layer pressure-sensitive adhesive assembly according to item 34, wherein the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer each independently comprise the pressure-sensitive adhesive composition according to any one of items 1 to 32.

[0174] Item 37 is the multilayer pressure-sensitive adhesive assembly of any one of items 1 to 36, wherein the polymer foam layer further comprises at least one filler material selected from the group consisting of microspheres, expandable microspheres, such as pentane-filled expandable microspheres, expanded microspheres, gaseous voids, glass beads, glass microspheres, glass bubbles, and any combination or mixture thereof.

[0175] Item 38 is the multi-layer pressure-sensitive adhesive assembly of item 37, wherein the at least one filler material is selected from the group consisting of expandable microspheres, glass bubbles, and any combination or mixture thereof.

[0176] Item 39 is the multilayer pressure-sensitive adhesive assembly of any one of items 1 to 38, having a volatile organic compound (VOC) value of less than 1500 ppm, less than 1200 ppm, less than 1000 ppm, less than 800 ppm, less than 600 ppm, less than 500 ppm, or less than 400 ppm, as measured by temperature programmed desorption analysis by test method VDA278.

[0177] Item 40 is the multi-layer pressure-sensitive adhesive assembly of any one of items 1-39 having a volatile fogging compounds (FOG) value of less than 4000 ppm, less than 3000 ppm, less than 2500 ppm, less than 2000 ppm, less than 1500 ppm, less than 1000 ppm, less than 800 ppm, or less than 600 ppm as measured by temperature programmed desorption analysis according to test method VDA278.

[0178] Item 41 is the multilayer pressure-sensitive adhesive assembly of any one of items 1-40 having a static shear strength value of greater than 300 minutes, greater than 500 minutes, greater than 1000 minutes, greater than 2000 minutes, greater than 4000 minutes, greater than 5000 minutes, greater than 6000 minutes, greater than 8000 minutes, or greater than 10000 minutes, when measured at 70°C (500g on polypropylene) by the Static Shear Test Method described in the Experimental Section.

[0179] Item 42 is the multilayer pressure-sensitive adhesive assembly of any one of items 1-41 having a static shear strength value of greater than 300 minutes, greater than 500 minutes, greater than 1000 minutes, greater than 2000 minutes, greater than 4000 minutes, greater than 5000 minutes, greater than 6000 minutes, greater than 8000 minutes, or greater than 10000 minutes, as measured at 90°C (500g on stainless steel) by the Static Shear Test Method described in the Experimental Section.

[0180] Item 43 is the multi-layer pressure-sensitive adhesive assembly of any one of items 1 to 42 having a peel strength value of greater than 30 N, greater than 35 N, or greater than 40 N per 10 mm, as measured at 23° C. on stainless steel by the peel test method described in the experimental section.

[0181] Item 44 is the multi-layer pressure-sensitive adhesive assembly of any one of items 1 to 43, having a peel strength value of greater than 20 N, greater than 25 N, or greater than 30 N per 10 mm, as measured at 23° C. on polypropylene by the peel test method described in the experimental section.

[0182] Item 45 is the multi-layer pressure-sensitive adhesive assembly according to any one of items 1 to 44, having an odor level of 3 or less by VDA270.

[0183] Item 46 is a method for producing a multi-layer pressure-sensitive adhesive assembly according to any one of items 1 to 45, comprising melt co-extruding, in particular hot melt co-extruding, a polymer foam layer, a first pressure-sensitive adhesive layer, and optionally a second pressure-sensitive adhesive layer.

[0184] Item 47 is combining the multi-arm block copolymer with at least one hydrocarbon tackifier to form a pressure sensitive adhesive formulation; and Melt co-extruding a polymer foam layer and a pressure sensitive adhesive formulation to form a multi-layer pressure sensitive adhesive assembly. 46. ​​A method for producing the multi-layer pressure-sensitive adhesive assembly according to any one of items 1 to 45, comprising:

[0185] Item 48 is the method of items 46 or 47, further comprising vacuum degassing at least one of the pressure sensitive adhesive formulation or the polymer foam layer.

[0186] Item 49 is the method of any one of items 46 to 48, further comprising incorporating a volatile organic compound (VOC) entraining additive into at least one of the pressure sensitive adhesive formulation or the polymer foam layer, wherein the VOC entraining additive is selected from the group consisting of water, carbon dioxide, nitrogen gas, and any combination thereof.

[0187] Item 50 is the method of any one of items 46-49, further comprising crosslinking the hot melt coextruded multi-layer pressure-sensitive adhesive assembly with actinic radiation or with E-beam radiation.

[0188] Item 51 is the use of the multi-layer pressure-sensitive adhesive assembly according to any one of items 1 to 45 for industrial applications, interior applications, construction market applications, automotive applications, or electronics applications.

[0189] Item 52 is the use according to item 51 for automotive applications, in particular for at least one of taped seals on the body, taped seals on the doors, exterior and interior part attachment, and weatherstrip tape applications.

[0190] Item 53 is the use of the multi-layer pressure-sensitive adhesive assembly according to any one of items 1 to 45 for bonding to low surface energy substrates and / or medium surface energy substrates.

[0191] The present disclosure is further illustrated by the following examples, which are merely for illustrative purposes and are not intended to limit the scope of the appended claims. EXAMPLES

[0192] Unless otherwise stated, all parts, percentages, ratios, etc. in the examples and elsewhere in this specification are by weight. The following abbreviations are used in this section: mg = milligram, g = gram, kg = kilogram, centimeter = cm, mm = millimeter, nm = nanometer, mL = milliliter, °C = degrees Celsius, N = Newton, h = hour, rpm = revolutions per minute, kV = kilovolts, MR = megarads, min = minute, SS = stainless steel, PP = polypropylene, and PS = polystyrene. [Table 1]

[0193] Test Method density calculation The density of the three-layer foam tape structure was calculated based on the coating weight (kg / m 2 The coating weight was determined by dividing the thickness (in mm) of the tape by the thickness (in mm) of the tape. The coating weight was determined by dividing the thickness (in mm) of the tape by ... sample layer. 2 The coating weight was then determined in kg / m 2 The thickness of the foam tape was measured using a thickness gauge manufactured by Mitutoyo (Japan).

[0194] 90° peel test at 300 mm / min (according to FINAT Test Method No. 2, 8th edition, 2009) A strip of a multi-layer pressure-sensitive adhesive assembly according to the present disclosure, measuring 10 mm wide and over 120 mm long, is cut longitudinally from the sample material.

[0195] To prepare the test specimens, first remove the liner from one adhesive surface and place it on a test coupon (stainless steel, polypropylene or polystyrene) with the following dimensions: 22 x 1.6 cm, thickness 0.13 mm. Stainless steel is available from Rocholl GmbH (Eschelbronn, Germany), polypropylene is available from Aquarius Plastics Ltd. (Guildford, Surrey, Great Britain), and polystyrene is available from Rocholl GmbH (Eschelbronn, Germany). The adhesive-coated side of each PSA assembly strip was then placed, adhesive side down after removing the liner, on a clean test panel using light finger pressure. The test specimen was then rolled twice with a standard FINAT test roller (weight 6.8 kg) at a speed of approximately 10 mm per second to obtain a close contact between the adhesive mass and the surface. After the PSA assembly strips were applied to the test panels, the test samples were allowed to sit at ambient room temperature (23° C.+ / -2° C., 50%+ / -5% relative humidity) for 72 hours prior to testing.

[0196] For the peel test, in a first step, the test sample was clamped in the lower movable jaw of a Zwick tensile tester (Model Z020, available from Zwick / Roell GmbH, Ulm, Germany). The multi-layer pressure-sensitive adhesive film strip was folded back at a 90° angle and its free end was gripped in the upper jaw of the tensile tester in a configuration typically utilized for 90° measurements. The tensile tester was set at a jaw separation speed of 300 mm per minute. Test results were expressed in Newtons per 10 mm (N / 10 mm). The quoted peel value was the average of two 90° peel measurements. The failure mode was generally foam splitting unless otherwise noted.

[0197] Static shear test at 500g, 70°C, 90°C and 105°C (FINAT Test Method No. 8, 8th edition, 2009) Testing was carried out at 70°C, 90°C or 105°C. Stainless steel is available from Rocholl GmbH, polypropylene is available from Aquarius Plastics Ltd. and polystyrene is available from Rocholl GmbH. The test specimens were cut to dimensions of 12.7mm x 25.4mm. The liner was then removed from one side of the specimen and the adhesive was glued onto an aluminium plate having the following dimensions: 25.4 x 50 x 1mm thick and containing a 10mm hole for a weight. The second liner was then removed from the specimens and a small panel with the test specimen was applied onto each test panel having the following dimensions: 50mm x 50mm x 2mm short side.

[0198] The test samples were then rolled twice with a standard FINAT test roller (weight 6.8 kg) at a speed of approximately 5 mm per second to obtain an intimate contact between the adhesive mass and the surface. After the pressure-sensitive adhesive assembly strip was applied to the test panel, the test samples were left at ambient room temperature (23°C + / - 2°C, 50% + / - 5% relative humidity) for 24 hours prior to testing. Each sample was then placed in a vertical shear stand (+2° configuration) at 70°C or 90°C equipped with an automatic time recorder. After a dwell time of 10 minutes in the oven, a 500g weight was hung in the hole of the aluminum plate. The time to failure was measured and recorded in minutes. Two samples were measured per specimen.

[0199] Temperature programmed desorption analysis of organic emissions according to VDA test method 278 VDA Method 278 is a test method used for the determination of organic emissions from non-metallic trim parts used in the manufacture of automotive interiors (VDA stands for "Verband der Automobilindustrie" of the German Association of Automobilists). The method classifies the emitted organic compounds into two groups: VOC value nC 25 The sum of volatile and semi-volatile compounds up to FOG value nC 14 From nC 32Sum of semi-volatile and heavy compounds up to For the VOC and FOG measurements, 30 mg + / - 5 mg of adhesive sample was weighed directly into an empty glass sample tube. Volatile and semi-volatile organic compounds were extracted from the sample into the gas stream and then recollected in a secondary trap before injection into the GC for analysis. An automated temperature programmed desorption apparatus (Gerstel TDU 2, manufactured by GERSTEL GmbH & Co. KG, Mulheim an der Ruhr, Germany) was used for the VDA 278 test.

[0200] The test method involves two extraction steps: VOC analysis: Samples were desorbed at 90°C for 30 minutes, and then 25 This involved extracting up to 100% VOCs, followed by semi-quantitative analysis of each compound as μg toluene equivalent per gram of sample. FOG analysis: Samples were desorbed at 120°C for 60 minutes and 14 ~nC 32 This involves extracting semi-volatile compounds in the range of 0.01 to 0.01 μg hexadecane equivalents per gram of sample, followed by semi-quantitative analysis of each compound as μg hexadecane equivalents per gram of sample.

[0201] The VOC and FOG values ​​reported were the average of two measurements per sample.

[0202] Odour test according to VDA test method 270 C3 The odour test is based on a method derived from VDA test method 270 C3 and is carried out according to the following procedure.

[0203] 200 cm of an exemplary multilayer structure 2 The samples were placed in 1000 mL glass bottles, which were then placed in an oven at 80° C. After 2 hours, the bottles were removed from the oven, cooled to a temperature of 60° C., and then graded by at least three testers according to the grading scale used in VDA270 in Table 2 (see below). [Table 2]

[0204] Preparation of acrylic polymer The acrylic polymers used in the following core formulations were prepared as described for polyacrylate polymers P1 and P2 in U.S. Patent Application Publication No. 2019 / 0345367 (Eckhardt et al.) using prepolymerized composition 1 with the following modifications: 0.048 parts IOTG was used and 0.4 parts ESACURE ONE photoinitiator was used instead of IRGACURE 651 photoinitiator.

[0205] Preparation of Skin Adhesive Pressure sensitive skin adhesive formulations having the compositions described in Table 3 (see below) were compounded in a 26 mm co-rotating twin screw extruder (ZSK26, Coperion GmbH, Stuttgart, Germany) with 15 heating zones (Z1-Z15) and an L / D (length / diameter) ratio of 60. [Table 3]

[0206] The block copolymer blend and tackifier were fed into Z1 by a solid-feed-loss-in-weight screw feeder (single screw feeder DDW-MD3-DSR28N-10Q, Brabender Technologie GmbH&Co.KG, Duisburg, Germany). A vacuum was applied to Z10. The screw speed of the twin screw extruder was 300 rpm and the throughput was around 10 kg / h. The temperature profile and extrusion conditions are listed in Table 4 (see below). [Table 4]

[0207] Core Formulation The foam core formulations described in Table 5 (see below) were compounded in a 30 mm co-rotating twin screw extruder (ZE30Ax64D UTXi, Krauss Maffei Berstorff GmbH, Hannover, Germany) with 23 heat zones (Z1-Z23) and an L / D (length / diameter) ratio of 64. [Table 5]

[0208] The temperature profile and extrusion conditions of the core extruder are listed in Table 6 (see below). The screw speed of the twin-screw extruder was 260 rpm and the throughput was 25 kg / h. The acrylic polymer was fed into the twin-screw extruder in zone Z2 using an acrylate feeder. Activated carbon was added in zone Z1 using a loss-in-weight screw feeder (twin-screw feeder DDW-M-DDSR20, Brabender Technologie GmbH&Co.KG, Duisburg, Germany). Expandable microspheres FN100MD were added in zone Z12 using a loss-in-weight twin-screw feeder (twin-screw feeder DDW-M-DDSR20, Brabender Technologie GmbH&Co.KG). Between the extruder and the die, the adhesive melt was metered by a gear pump (GPA36 / 36-03 12Z CW, Nordson PPS GmbH, Munster, Germany) (140° C.) through a heated hose (140° C.) that formed the junction between the extruder and the die. The temperature of the coating die was set at 160° C. The expandable microspheres could only expand after passing through the three-layer die at the end of the extrusion process, resulting in a three-layer foam tape. [Table 6]

[0209] Examples 1 to 6 (Ex1 to Ex6) and Illustrative Examples A to H (IllExA to IllExH) The extruded three-layer foam structures were coated onto a red siliconized polyethylene liner and cured by E-beam irradiation at 260 kV and 8.5 MR intensity. The examples were subjected to the test methods described above and the results are shown in Tables 7 and 8 below.

[0210] As a comparative example, an adhesive obtained from Tesa SE (Norderstedt, Germany) was also evaluated. Tesa "7065" adhesive was measured to have a VDA278 VOC of 2540 ppm, a VDA278 FOG of 7870 ppm, and a VDA270C3 odor rating of 5.2. The results for Tesa "92111" adhesive are shown in Table 7 below as Comparative Example 1 (CE1).

[0211] The results in Table 8 show good peel and static shear adhesion performance for Skins 2-4 and 6-8. Any of these skins can be combined with any of Cores 2-6 and are expected to have desirable VOC, FOG and odor values, as shown in Examples 1-7 in Table 7. [Table 7] [Table 8]

[0212] The above description is provided to enable one skilled in the art to practice the patented invention and should not be construed as limiting the scope of the invention, which is defined by the claims and all equivalents thereof.

Claims

1. 1. A multi-layer pressure-sensitive adhesive assembly comprising: a polymeric foam layer; and a first pressure-sensitive adhesive layer adjacent to the polymeric foam layer, the polymeric foam comprising a plurality of activated carbon particles dispersed therein; and the first pressure-sensitive adhesive comprising: a compound represented by the formula Q in an amount greater than 20 weight percent based on the total weight of the first pressure-sensitive adhesive layer ｎ Multi-arm block copolymers having -Y: [In the formula, Q represents an arm of a multi-arm block copolymer, each arm independently having the formula G-R; n represents the number of arms and is an integer of at least 3; Y is a residue of a multifunctional coupling agent; each R is a rubbery block comprising a polymerized conjugated diene, a hydrogenated derivative of a polymerized conjugated diene, or a combination thereof, and each G is a glassy block comprising a polymerized monovinyl aromatic monomer; at least one hydrocarbon tackifier; 1. A multi-layer pressure-sensitive adhesive assembly comprising:

2. the first pressure-sensitive adhesive layer comprising: the multi-arm block copolymer in an amount ranging from 25 weight percent to 60 weight percent based on the total weight of the first pressure-sensitive adhesive layer; the hydrocarbon tackifier in an amount of 40 weight percent to 60 weight percent based on the total weight of the first pressure-sensitive adhesive layer; an amount of from 0 weight percent to 35 weight percent, based on the total weight of the first pressure-sensitive adhesive layer, of formula L-(G) ｍ A linear block copolymer having: [In the formula, L is a rubbery block comprising a polymerized olefin, a polymerized conjugated diene, a hydrogenated derivative of a polymerized conjugated diene, or any combination thereof; G is a glassy block comprising polymerized monovinyl aromatic monomers; m is 1 or 2] The multi-layer pressure-sensitive adhesive assembly of claim 1 , comprising:

3. The formula L-(G) ｍ wherein the rubbery block L of the linear block copolymer having the formula L-(G) comprises at least one of polyisobutylene, polyisoprene, or polybutadiene. ｍ 3. The multi-layer pressure-sensitive adhesive assembly of claim 2, wherein at least one of the glassy blocks G of the linear block copolymer having the formula:

4. the first pressure-sensitive adhesive layer has a glass transition temperature greater than 25°C, a weight average molecular weight of 1000 grams / mole to 100,000 grams / mole, and is substantially free of (meth)acrylate copolymers comprising (meth)acrylic acid ester monomer units that, when homopolymerized, have a glass transition temperature greater than 25°C; or the first pressure-sensitive adhesive layer being substantially free of polymeric plasticizers having a weight average molecular weight of at least 10,000 grams / mole; The multi-layer pressure-sensitive adhesive assembly according to any one of claims 1 to 3, which satisfies at least one of the following conditions:

5. The polymerized conjugated diene in R comprises at least one of polyisoprene or polybutadiene, and the formula Q ｎ 4. The multi-layer pressure-sensitive adhesive assembly of claim 1, wherein at least one of the glassy blocks of the multi-arm block copolymer having -Y comprises polymerized monovinyl aromatic monomers comprising at least one of styrene or alkylated styrenes.

6. The multi-layer pressure-sensitive adhesive assembly of any one of claims 1 to 3, which is crosslinked by electron beam crosslinking.

7. The activated carbon particles have a 100 m ２ / g to 2000m ２ / g, or the activated carbon particles are present in the polymer foam in an amount in the range of 0.1 weight percent to 15 weight percent, based on the total weight of the polymer foam; The multi-layer pressure-sensitive adhesive assembly according to any one of claims 1 to 3, which satisfies at least one of the following conditions:

8. the polymer foam comprises a polymer-based material comprising at least one of polyacrylate, polyurethane, polyolefin, polyamine, polyamide, polyester, polyether, polyisobutylene, polystyrene, natural rubber, rubber-based elastomeric material, polyvinyl, or polyvinylpyrrolidone; or The polymer foam is 60% to 100% by weight, based on the weight of the polymer foam, of (meth)acrylic acid ester monomer units having a linear or branched alkyl group having 1 to 32 carbon atoms; 0% to 40% by weight, based on the weight of the polymer foam, of acrylic acid monomer units; 0% to 20% by weight, based on the weight of the polymer foam, of expandable microspheres; The multi-layer pressure-sensitive adhesive assembly of any one of claims 1 to 3, comprising:

9. a second pressure-sensitive adhesive layer adjacent the polymer foam layer and opposite the first pressure-sensitive adhesive layer, the second pressure-sensitive adhesive layer independently comprising: a compound represented by the formula Q in an amount greater than 20 weight percent based on the total weight of the first pressure-sensitive adhesive layer ｎ Multi-arm block copolymers having -Y: [In the formula, Q represents an arm of a multi-arm block copolymer, each arm independently having the formula G-R; n represents the number of arms and is an integer of at least 3; Y is a residue of a multifunctional coupling agent; each R is a rubbery block comprising a polymerized conjugated diene, a hydrogenated derivative of a polymerized conjugated diene, or a combination thereof, and each G is a glassy block comprising a polymerized monovinyl aromatic monomer; at least one hydrocarbon tackifier; The multi-layer pressure-sensitive adhesive assembly of any one of claims 1 to 3, comprising:

10. 4. The multi-layer pressure-sensitive adhesive assembly of any one of claims 1 to 3, having at least one of a volatile organic compound (VOC) level of less than 500 ppm per VDA 278, a volatile fogging compound (FOG) level of less than 1000 ppm per VDA 278, or an odor level of 3 or less per VDA 270.