Adhesive comprising tackifying elastomer composition in liquid vehicle and related methods

Abstract

An adhesive comprising a tackifying elastomer composition present in at least one of a form dissolved in a liquid vehicle or a form dispersed in the liquid vehicle. The tackifying elastomer composition comprises a block copolymer comprising at least one polystyrene terminal block, a terpene resin, and a polyphenylene ether resin. Also disclosed is a method of making a bonded article comprising spraying the adhesive and the use of the adhesive as a spray adhesive.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to U.S. Provisional Application No. 63 / 465,687, filed May 11, 2023, and U.S. Provisional Application No. 63 / 641,261, filed May 1, 2024, the disclosures of which are incorporated herein by reference in their entirety. Background Technology

[0003] Styrene-conjugated diene block copolymers have been formulated to produce adhesive compositions. For example, U.S. Patent No. 3,239,478 (Harlan) shows combinations of these block copolymers with tackifying resins and paraffinic additive oils to produce various types of adhesives. However, one limitation of these adhesive compositions is their relatively low operating temperature. U.S. Patent SIRH 1387 (Hansen et al.) and U.S. Patent No. 4,104,323 (Hansen) propose using polyphenylene ethers melt-blended with resins compatible with other end blocks to improve the performance of styrene-conjugated diene block copolymer-based hot-melt processing adhesives at relatively high temperatures.

[0004] U.S. Patent Application Publication No. 2021 / 0130662 (Chastek et al.) describes a melt-processable pressure-sensitive adhesive comprising block copolymers, polyphenylene ethers, and hydrocarbon tackifiers, and requiring (meth)acrylic functional additives with glass transition temperatures in the range of 50°C to 160°C. Chastek et al. note that pressure-sensitive adhesives (“PSA”) are adhesives that are generally tacky at room temperature and can adhere to a substrate surface by applying slight pressure, and do not require solvents, water, or heat to activate the adhesive. Summary of the Invention

[0005] In one aspect, this disclosure provides an adhesive comprising at least one of a tackifying elastomer composition present in a liquid carrier or dispersed in the liquid carrier. The tackifying elastomer composition comprises a block copolymer containing at least one polystyrene-terminated block, a terpene resin, and a polyphenylene ether resin.

[0006] In another aspect, this disclosure provides a method for manufacturing an adhesive article comprising a first substrate and a second substrate. The method includes spraying an adhesive onto at least one of the first substrate or the second substrate, and using the adhesive to adhere the first substrate and the second substrate. In some embodiments, the method further includes evaporating a portion of a liquid carrier prior to adhering the first substrate and the second substrate.

[0007] In another aspect, this disclosure provides the use of the adhesive as a spray adhesive.

[0008] In another aspect, the present disclosure provides a tape comprising and / or made from an adhesive disposed on a tape backing.

[0009] In this application:

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

[0011] The phrase "at least one of following list" followed by a list of items refers to any one of the items in the list and any combination of two or more items in the list. The phrase "at least one of following list" followed by a list of items refers to any one of the items in the list or any combination of two or more items in the list.

[0012] The term "polystyrene" as used herein includes polymers and copolymers of substituted styrene monomers and / or unsubstituted styrene.

[0013] The phrase "based on the total weight of the tackifying elastomer composition" does not include the liquid carrier in the adhesive composition of the present disclosure.

[0014] "Dispersed" refers to a heterogeneous mixture of the tackifying elastomer composition as discrete particles or droplets in a liquid carrier. "Dispersed" does not encompass "dissolved."

[0015] The term "elastomer" refers to a molecule having a structure that essentially comprises a plurality of repeating units, which are actually or conceptually derived from a low relative molecular mass monomer. The term "elastomer" refers to a polymer having elastic properties.

[0016] Unless otherwise indicated, all numerical ranges are inclusive of the numbers at the ends of the range and non-integral values between the numbers at the ends of the range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.). DETAILED DESCRIPTION

[0017] For elastomeric compositions comprising block copolymers comprising one or more polystyrene end blocks tackified with certain terpene resins, especially aromatic modified terpene resins, the inventors have observed incompatibility between the block copolymer and the terpene resin, which results in phase separation of the tackifier from the rubber. Compatibility between the block copolymer and the terpene resin tackifier is important for achieving good adhesion properties. This compatibility becomes more important in compositions having relatively high amounts of tackifier, for example, a weight ratio of terpene resin to block copolymer greater than 1 : 1 or at least 1.5: 1, 1.6: 1, 1.7: 1, or 1.9: 1. Compatibility in tackified elastomeric compositions comprising block copolymers and terpene resins can be evaluated using rheology. In a rheology curve, incompatibility can be evidenced by a broader tan delta peak with a lower tan delta peak height and a secondary tan delta peak or increasing tan delta values at higher temperatures. The secondary tan delta peak can be attributed to excess tackifier that is not fully incorporated into the elastomer.

[0018] The present disclosure provides tackified elastomeric compositions having improved compatibility. The addition of polyphenylene ether resin alters the rheology curve and unexpectedly reduces the high temperature tan delta values. As shown by the comparison of Control Example A and Examples 1-5, the addition of polyphenylene ether resin results in a reduction in tan delta values at 120°C and provides an enhancement in adhesion properties and high temperature adhesion properties. Similarly, as shown by the comparison of Control Example E and Examples 13-17, the addition of polyphenylene ether resin results in a reduction in tan delta values at 100°C and provides an enhancement in adhesion properties and high temperature adhesion properties. Such benefits have been observed in various adhesive compositions having different levels of tackifier and / or different types of block copolymers. Furthermore, as shown by the examples below, tackified elastomeric compositions comprising a block copolymer having at least one polystyrene end block, a terpene resin, and a polyphenylene ether resin provide the same rheology curve after aging at 120°F (49°C) for about 2 weeks. These results demonstrate the stability (e.g., lack of phase separation) of the tackified elastomeric compositions.

[0019] The tackified elastomeric compositions in the adhesives of the present disclosure comprise a block copolymer comprising at least one polystyrene end block. The tackified elastomeric composition can comprise a single block copolymer or a mixture of two or more block copolymers. In some embodiments, at least one block copolymer in the tackified elastomeric composition is a block copolymer comprising a middle block and two or more polystyrene end blocks. The middle block is typically a rubbery block (or low Tg block), and the polystyrene end blocks are sometimes referred to as glassy blocks or high Tg blocks.

[0020] While the present disclosure is not bound by theory, it is believed that at the working temperature of the adhesive, the block copolymer microphase separates into ordered nanoscale domains that include rubbery block domains and glassy block domains. When microphase separated, these copolymers form elastic, dimensionally stable solids that exhibit significant shear strength. Unlike chemically crosslinked rubbers, block copolymers are capable of reversibly melting and resolidifying; thus, they are referred to as thermoplastic elastomers.

[0021] In some embodiments, the block copolymer is a linear block copolymer having the general formula

[0022] (S-R) m -S, where each S is independently a polystyrene block, each R is independently a rubbery block, and m is a value of at least 1. The variable m can be 1 to 10, 1 to 5, 1 to 3, or in some embodiments, less than, equal to, or greater than 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. In some embodiments, the linear block copolymer is a triblock copolymer, where m is 1 and can also be represented by the formula S-R-S.

[0023] In some embodiments, the block copolymer can be a star (also referred to as radial or multi-armed) block copolymer of the general formula (S-R) n -Y, where each R and S are independently the same as defined above, n is an integer equal to at least 3, and Y is a residue of a multifunctional coupling agent used to form the star block copolymer. The variable n represents the number of arms in the star block copolymer and can be 3 to 10, 3 to 8, 3 to 6, or in some embodiments, less than, equal to, or greater than 3, 4, 5, 6, 7, 8, 9, or 10.

[0024] In the block copolymers (including any of the above), the polystyrene blocks can have the same or different molecular weights. In some embodiments, each polystyrene block independently has a weight average molecular weight of 4,000 grams / mole to 50,000 grams / mole. Similarly, if there is more than one intermediate block (e.g., a rubbery block), the intermediate blocks can have the same or different molecular weights. In some embodiments, each intermediate block independently has a weight average molecular weight of 5,000 grams / mole to 500,000 grams / mole.

[0025] Generally, each intermediate block has a glass transition temperature (T gFor example, the glass transition temperature can be less than 20°C, less than 0°C, less than -10°C, or less than -20°C, less than -40°C, less than -60°C, or in some embodiments, less than, equal to, or greater than -60°C, -55°C, -50°C, -45°C, -40°C, -35°C, -30°C, -25°C, -20°C, -15°C, -10°C, -5°C, 0°C, 5°C, 10°C, 15°C, or 20°C. Glass transition temperatures can be determined using conventional methods known in the art, including differential scanning calorimetry or dynamic mechanical analysis.

[0026] In some embodiments, each midblock in the block copolymer is a polymerization product of a conjugated diene, a hydrogenated derivative of the polymerized conjugated diene, or a combination thereof. The conjugated diene often contains 4 to 12 carbon atoms. Examples of useful conjugated dienes include butadiene, isoprene, 2-ethylbutadiene, 1-phenylbutadiene, 1,3-pentadiene, 1,3-hexadiene, 2,3-dimethyl-1,3- butadiene, 3-ethyl-1,3-hexadiene, and combinations thereof. Each midblock can be a homopolymer or a copolymer. In some embodiments, the midblock comprises at least one of poly(butadiene), poly(isoprene), poly(2-ethylbutadiene), poly(1-phenylbutadiene), poly(1,3-pentadiene), poly(1,3-hexadiene), poly(2,3-dimethyl-1,3-butadiene), poly(3-ethyl-1,3-hexadiene), poly(ethylene / propylene), poly(ethylene / butylene), or poly(isoprene / butadiene). In some embodiments, the midblock comprises at least one of polybutadiene, polyisoprene, poly(isoprene / butadiene), poly(ethylene / butylene), poly(ethylene / propylene), or polyisobutylene.

[0027] The glass transition temperature of each polystyrene block is typically at least 50°C, at least 60°C, at least 70°C, at least 80°C, at least 90°C, at least 100°C, or in some embodiments, less than, equal to, or greater than 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, or 100°C.

[0028] Styrene monomers useful in making the polystyrene end blocks can be unsubstituted or substituted. Useful styrene monomers have at least 8 carbon atoms, and in some embodiments contain at least 10 carbon atoms or at least 12 carbon atoms and up to 18 carbon atoms, up to 16 carbon atoms, or up to 14 carbon atoms. Examples of suitable styrene monomers include styrene, vinyltoluene (e.g., 2-vinyltoluene, 3-vinyltoluene, or 4-vinyltoluene), a-methylstyrene, 2,4-dimethylstyrene, ethylstyrene, 2,4-diethylstyrene, 3,5-diethylstyrene, a-2-methylstyrene, 4-tert-butylstyrene, 4-isopropylstyrene, and combinations thereof. Each polystyrene block can be a homopolymer or a copolymer. In some embodiments, the polystyrene end blocks each comprise at least one of unsubstituted polystyrene, poly(vinyltoluene), poly(a-methylstyrene), poly(2,4-dimethylstyrene), poly(ethylstyrene), poly(2,4-diethylstyrene), poly(3,5-diethylstyrene), poly(4-tert-butylstyrene), or poly(4-isopropylstyrene). In some embodiments, the polystyrene end blocks each comprise unsubstituted polystyrene. In some embodiments where one or more of the polystyrene end blocks comprise a copolymer, at least 50 weight percent (wt%) (in some embodiments, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, at least 98 wt%, or at least 99 wt%) of the monomer units are derived from styrene.

[0029] The polystyrene blocks comprising the polystyrene end blocks can comprise 5 weight percent to 50 weight percent of the block copolymer. With this amount of polystyrene in the block copolymer, a useful balance of cohesive strength and modulus can be achieved. The block copolymer can have a polystyrene block content of 7 wt% to 40 wt%, 9 wt% to 33 wt%, 13 wt% to 25 wt%, or in some embodiments, less than, equal to, or greater than 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, 25 wt%, 27 wt%, 30 wt%, 32 wt%, 35 wt%, 37 wt%, or 40 wt%, based on the total weight of the block copolymer.

[0030] In addition to the polystyrene blocks and midblocks, the star block copolymer also includes residues of a multifunctional coupling agent Y. The coupling agent typically has multiple carbon-carbon double bonds, carbon-carbon triple bonds, or other groups that can react with a carbanion of a living polymer that can be used to form the star block copolymer. The multifunctional coupling agent can be aliphatic, aromatic, heterocyclic, or a combination thereof. Examples of suitable coupling agents include polyvinyl acetylene, diacetylene, di(meth)acrylate (e.g., di(meth)acrylate ethylene glycol), divinylbenzene, divinylpyridine, and divinylthiophene. Other useful coupling agents include multifunctional silyl halides (e.g., tetrafunctional silyl halides), polyepoxides, polyisocyanates, polyketones, polyanhydrides, polyalkenyls, and dicarboxylic acid esters.

[0031] The weight average molecular weight of the block copolymer is typically no greater than 1,200,000 grams per mole (g / mol). In some embodiments, the weight average molecular weight is no greater than 1,050,000 g / mol, 900,000 g / mol, 800,000 g / mol, 600,000 g / mol, or 500,000 g / mol. In some embodiments, the weight average molecular weight of the block copolymer is at least 75,000 g / mol, at least 100,000 g / mol, at least 200,000 g / mol, at least 300,000 g / mol, or at least 400,000 g / mol. The weight average molecular weight of the block copolymer can be from 75,000 g / mol to 1,200,000 g / mol, from 100,000 g / mol to 1,000,000 g / mol, from 100,000 g / mol to 900,000 g / mol, or from 100,000 g / mol to 500,000 g / mol.

[0032] In some embodiments, the tackifying elastomer composition includes a diblock copolymer. The diblock copolymer typically has a single polystyrene block and a single rubbery block, and can be represented herein by the chemical structure S-R, where S and R are as defined above in any of its embodiments.

[0033] The polystyrene block content in the diblock copolymer can be from 10 wt% to 50 wt%, from 10 wt% to 40 wt%, from 15 wt% to 50 wt%, from 15 wt% to 40 wt%, from 20 wt% to 50 wt%, from 20 wt% to 40 wt%, or in some embodiments, less than, equal to, or greater than 10 wt%, 12 wt%, 15 wt%, 17 wt%, 20 wt%, 22 wt%, 25 wt%, 27 wt%, 30 wt%, 32 wt%, 35 wt%, 37 wt%, or 40 wt%, relative to the total weight of the diblock copolymer. The weight average molecular weight of the diblock copolymer can be from 75,000 g / mol to 250,000 g / mol, from 100,000 g / mol to 250,000 g / mol, from 125,000 g / mol to 250,000 g / mol, or from 125,000 g / mol to 200,000 g / mol.

[0034] In some embodiments, the block copolymer includes at least one of a polystyrene-containing diblock copolymer, a polystyrene-containing triblock copolymer, or a polystyrene-containing star block copolymer, wherein each of the polystyrene-containing diblock copolymer, the polystyrene-containing triblock copolymer, and the polystyrene-containing star block copolymer independently includes blocks of at least one of polyisoprene, polybutadiene, poly(ethylene / propylene), poly(ethylene / butylene), or polyisobutylene. In some embodiments, the block copolymer includes at least one of a polystyrene-containing diblock copolymer, a polystyrene-containing triblock copolymer, or a polystyrene-containing star block copolymer, wherein each of the polystyrene-containing diblock copolymer, the polystyrene-containing triblock copolymer, and the polystyrene-containing star block copolymer independently includes blocks of at least one of polyisoprene or polybutadiene. In some embodiments, the block copolymer includes at least one of a styrene-isoprene-styrene triblock copolymer or a styrene-butadiene-styrene triblock copolymer. In some embodiments, the block copolymer includes a styrene-butadiene-styrene triblock copolymer and a styrene-isoprene-styrene triblock copolymer. In some embodiments, the block copolymer includes a ratio of styrene-butadiene-styrene triblock copolymer and styrene-isoprene-styrene triblock copolymer of at least 1 : 1, 2: 1, 3: 1, 4: 1, 5: 1, or 10: 1, and at most 25: 1, 20: 1, 10: 1, or 5: 1. In some embodiments, the block copolymer includes a diblock copolymer and a triblock copolymer, including those described in any of the preceding embodiments, wherein the diblock copolymer is present in an amount of from 10 wt% to 90 wt%, from 20 wt% to 90 wt%, or from 50 wt% to 85 wt%, based on the total weight of the triblock copolymer and the diblock copolymer.

[0035] The block copolymer can be present in the tackifying elastomer composition in any suitable amount. In some embodiments, the block copolymer is present in an amount of 20 to 60 weight percent, 20 to 50 weight percent, 20 to 40 weight percent, or less than 50 weight percent, based on the total weight of the tackifying elastomer composition.

[0036] Suitable materials for use as the block copolymer, alone or in combination, are commercially available, for example, under the trade designation KRATON (e.g., KRATON D1161P, D1118, D1119, and A1535) from Kraton Performance Polymers (Houston, TX, USA), under the trade designation SOLPRENE (e.g., SOLPRENE S-1205) from Dynasol (Houston, TX, USA), under the trade designation QUINTAC from Zeon Chemicals (Louisville, KY, USA), and under the trade designations VECTOR and TAIPOL from TSRC Corporation (New Orleans, LA, USA).

[0037] The tackifying elastomer composition in the adhesive of the present disclosure comprises a terpene resin. Terpene resins useful in the tackifying elastomer composition include polyterpene homopolymers, copolymers of more than one terpene monomer, copolymers of one or more terpene monomers with one or more additional monomers, and hydrogenated products of any of these polymers. Examples of terpene monomers useful in any of these terpene resins include a-pinene, b-pinene, dipentene, and limonene. Catalytic cationic and anionic polymerization of terpenes is known. Monomers suitable for copolymerization with terpenes include styrene, a-methylstyrene, vinyltoluene, and any of the other substituted styrene monomers listed above. Copolymers of terpenes with styrene and substituted styrene monomers are referred to herein as aromatic modified terpene resins. Additional monomers suitable for copolymerization with terpenes include phenols such as phenol, cresol, and bisphenol. Copolymers of terpenes with phenolic monomers are referred to herein as terpene phenolic resins. In some embodiments, the terpene resin is an aromatic modified terpene resin. In some embodiments, the aromatic modified terpene is not a terpene-phenolic resin. In some embodiments, the terpene resin is a copolymer of terpene and at least one of styrene or a substituted styrene.

[0038] The terpene resins, including any of those described above, can have a number average molecular weight in the range of 600 g / mol to 10,000 g / mol and a softening point of 60 °C to 150 °C. In some embodiments, the terpene resin has a number average molecular weight of at most about 5000 g / mol, 4000 g / mol, 2500 g / mol, 2000 g / mol, or 1500 g / mol. In some embodiments, the number average molecular weight is in the range of 200 g / mol to 5000 g / mol, in the range of 200 g / mol to 4000 g / mol, in the range of 200 g / mol to 2000 g / mol, or in the range of 200 g / mol to 1500 g / mol. The number average molecular weight is determined using gel permeation chromatography according to methods known to those skilled in the art. In some embodiments, the terpene resin has a softening point of at least 70 °C, at least 80 °C, at least 90 °C, at least 100 °C, or at least 110 °C, measured using a ring and ball apparatus.

[0039] Examples of suitable terpene resins and hydrogenated terpene resins include those available under the trade designation CLEARON (e.g., CLEARON P150 and P135) from Yasuhara Chemical Company, Ltd. Hiroshima, Japan. Examples of suitable terpene phenolic resins include those available under the trade designation YS POLYSTER (e.g., POLYSTER T115, T160, T130, S145, and G150) from Yasuhara Chemical Company. Examples of suitable aromatic modified terpene resins include those available under the trade designation “YS RESIN TO” and “YS RESIN TR” from Yasuhara Chemical Company.

[0040] The terpene resin can be present in the tackifying elastomer composition in any suitable amount. In some embodiments, the terpene resin is present in an amount of 40 wt% to 75 wt%, 40 wt% to 70 wt%, 45 wt% to 65 wt%, greater than 50 wt%, or greater than 45 wt%, based on the total weight of the tackifying elastomer composition. In some embodiments, the weight ratio of terpene resin to block copolymer is greater than 1 : 1. In some embodiments, the weight ratio of terpene resin to block copolymer is at least 1.5: 1, 1.6: 1, 1.7: 1, 1.9: 1, and can be at most 2: 1, 2.5: 1, or greater.

[0041] As taught in U.S. Patent Application Publication No. 2021 / 0130662 (Chastek et al.), if the amount of tackifier, such as terpene, is greater than 50 wt% relative to the total weight of the adhesive composition, the level of tackifier can be too high and the resulting composition can not be a pressure sensitive adhesive. Thus, U.S. Patent Application Publication No. 2021 / 0130662 (Chastek et al.) will be understood to discourage a weight ratio of terpene rosin to block copolymer greater than 1 : 1, in some embodiments, at least 1.5: 1, 1.6: 1, 1.7: 1, 1.9: 1, and can be at most 2: 1, 2.5: 1, or greater.

[0042] PSAs are generally known to have the following desirable properties: (1) strong and permanent tack, (2) adhesion with no more than finger pressure, (3) ability to hold onto adherends, and (4) sufficient cohesive strength to be removed cleanly from adherends. Materials that have been found to work well as PSAs are polymers designed and formulated to exhibit the desired viscoelasticity to achieve the desired balance of tack, peel adhesion, and shear holding power. The Dahlquist criteria are commonly used to describe such performance of PSAs. The Dahlquist criteria for PSAs indicate that the shear storage modulus G’ should not exceed 0.3 megapascals (MPa) at 25 °C when an oscillatory strain of 1 hertz (Hz) is applied in the linear viscoelastic region of the PSA. When the Dahlquist criteria are exceeded, PSAs often lose their tack and adhesion buildup no longer occurs properly. Thus, the Dahlquist criteria represent an upper limit for the storage modulus used to achieve PSA properties. In some embodiments, the present disclosure provides adhesive films that exceed the Dahlquist criteria (e.g., greater than 0.3 MPa at 25 °C), but in combination with a liquid carrier provide excellent adhesive properties, in some embodiments, pressure sensitive adhesive properties.

[0043] The tackified elastomeric composition in the adhesive of the present disclosure includes a polyphenylene ether resin, which can also be referred to as a polyphenylene oxide resin. A combination of two or more polyphenylene ether resins can be used in the tackified elastomeric composition. In some embodiments, the polyphenylene ether resin contains repeating units shown in the following Formula I:

[0044]

[0045] I

[0046] and isomers thereof, wherein each R 1independently hydrogen, halogen, alkyl, haloalkyl having at least two carbon atoms between the halogen atom and the phenyl nucleus, alkoxy, and haloalkoxy having at least two carbon atoms between the halogen atom and the phenyl nucleus. In some embodiments, each R 1 is a methyl group, and the polyphenylene ether is poly(2,6-dimethyl-l,4-phenylene ether). In some embodiments, each R 1 is hydrogen (i.e., poly(p-phenylene ether). In some embodiments, the bond is not in the para position, as shown in Formula I.

[0047] In some embodiments, the polyphenylene ether resin has a number average molecular weight (Mw) of 300 g / mol to 25,000 g / mol, 300 g / mol to 10,000 g / mol, 1,000 g / mol to 8,000 g / mol, or in some embodiments, less than, equal to, or greater than 1,000 g / mol, 1,200 g / mol, 1,500 g / mol, 1,700 g / mol, 2,000 g / mol, 2,500 g / mol, 3,000 g / mol, 3,500 g / mol, 4,000 g / mol, 4,500 g / mol, 5,000 g / mol, 5,500 g / mol, 6,000 g / mol, 6,500 g / mol, 7,000 g / mol, 7,500 g / mol, or 8,000 g / mol, 10,000 g / mol, 25,000 g / mol, or 50,000 g / mol. The number average molecular weight is determined using gel permeation chromatography according to methods known to those skilled in the art.

[0048] The polyphenylene ether resin can be prepared by any known method. Suitable methods of preparation are described in U.S. Patent Nos. 3,306,874 (Hay); 3,306,875 (Hay); 3,257,357 (Stamatoff); and 3,257,358 (Stamatoff). Examples of suitable polyphenylene ether resins are commercially available under the trade designations “NORYL SA90” and “NORYL SA120” from Sabic, Houston, TX, and under the trade designation “STARAIR” from China Bluestar International Chemical Co., Ltd., Beijing, China.

[0049] In some embodiments, the polyphenylene ether resin is present in the tackified elastomeric composition in an amount of 1 to 20, 2 to 18, or 3 to 16 weight percent, based on the total weight of the tackified elastomeric composition. In some embodiments, the weight ratio of block copolymer to polyphenylene ether is in the range of 3: 1 to 25: 1, 3: 1 to 15: 1, or 3: 1 to 10: 1.

[0050] While other aromatic tackifying resins can be used in the tackified elastomeric composition, in some embodiments, the tackified elastomeric composition does not include a significant amount of other aromatic resins reported to enhance the styrene end block of the block copolymer. Such aromatic resins include benzofuran-indene resins, poly alpha methyl styrene, polystyrene resins, vinyl toluene-a-methyl styrene copolymers, polyindene resins. In some embodiments, the tackified elastomeric composition includes no more than 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0.5, or 0.1 weight percent of any of these aromatic resins, unless where any of these aromatic resins is part of the aromatic modified terpene resin. In some embodiments, the adhesive is free of any one or more of these aromatic resins. As shown in the examples below, the compatibility of the mixture of the polyphenylene ether resin with the block copolymer and the terpene resin is unexpectedly higher than another aromatic resin. For example, when a thermoplastic resin made from purified aromatic hydrocarbon monomers (available under the trade designation "ENDEX 155" from Synthomer, Kingsport, TN) was used in place of the polyphenylene ether in Control Example C, an additional tan delta peak was observed at 65 °C and tan delta rose significantly above 100 °C, which was not observed when the polyphenylene ether was used in the tackified elastomeric compositions in Examples 6, 7, and 9-11.

[0051] A variety of auxiliaries can also be used in the tackified elastomer composition of the adhesive of the present disclosure. Examples of such auxiliaries include antioxidants such as hindered phenols, amines, sulfur and phosphorus hydroperoxide decomposers, and butylated hydroxytoluene (BHT); inorganic fillers such as talc, zinc oxide, titanium dioxide, aluminum oxide, and silica; and plasticizing auxiliaries such as those described as plasticizers in Dictionary of Rubber, K. F. Heinisch, p. 359, John Wiley & Sons, New York (1974), oils, elastomeric oligomers, and waxes. Useful commercially available antioxidants include those available under the trade designations "IRGANOX" and "IRGAFOS" such as "IRGANOX 1010" and "IRGANOX 1520" from BASF, Florham Park, NJ, and those available under the trade designation "SONGNOX" from Songwon Ind. Co, Ulsan, Korea. Useful plasticizing oils include paraffinic, aromatic, and naphthenic oils such as those available, for example, from Process Oils Inc., Houston, TX. The plasticizing oil can be selected, for example, based on viscosity. If desired, the compositions according to the present disclosure can also include at least one of pigments, dyes, ultraviolet light absorbers, hindered amine light stabilizers, and heat stabilizers (e.g., sodium benzoate). When present, typically, antioxidants are present in the tackified elastomer composition in an amount of 0.1 to 5 parts by weight per 100 parts by weight of block copolymer; typically, ultraviolet light absorbers are present in the tackified elastomer composition in an amount of 0.1 to 3 parts by weight per 100 parts by weight of block copolymer; inorganic fillers can be present in the tackified elastomer composition in an amount of up to 50 parts by weight per 100 parts by weight of block copolymer; and plasticizing auxiliaries are present in the composition in an amount of 1 to 30, 20, 15, or 10 percent by weight of the total adhesive weight.

[0052] The tackified elastomer composition of the adhesive of the present disclosure can also include other thermoplastic materials, for example, ethylene-vinyl acetate, which can be used to enhance the spray pattern of the adhesive. When present, ethylene-vinyl acetate can be present in the tackified elastomer composition in an amount of 1 to 20 or 5 to 15 parts by weight per 100 parts by weight of block copolymer.

[0053] The adhesives of the present disclosure include a liquid carrier, and the tackified elastomeric composition is present in at least one of a form dissolved in the liquid carrier or a form dispersed in the liquid carrier. The liquid carrier can include an organic solvent, water, or a combination thereof. The amount of liquid carrier is generally inversely proportional to the amount of other components in the adhesives of the present disclosure. Any liquid carrier described herein or any combination of liquid carriers described herein can be present in the adhesive in at least 50 wt%, 55 wt%, 60 wt%, 70 wt%, 75 wt%, 80 wt%, 90 wt%, or 95 wt%, based on the total weight of the adhesive.

[0054] In some embodiments, the liquid carrier includes a hydrocarbon solvent. Useful hydrocarbon solvents include aromatic hydrocarbon solvents (e.g., toluene and xylene), saturated hydrocarbon solvents having 5 to 9 or 5 to 8 carbon atoms, and mixtures thereof. Examples of suitable saturated hydrocarbon solvents include n-pentane, isopentane, n-hexane, isohexane, n-heptane, isohexane, n-octane, isooctane, nonane, cyclopentane, methylcyclohexane, and cyclohexane. Additional examples of useful hydrocarbon solvents include isoparaffin solvents available under the trade designations “ISANE IP 130” and “ISANE IP 175” from Total Fina, Paris, France, and under the trade designation “ISOPAR” from Exxon Mobil Chemicals, Houston, TX. Mixtures of any of these solvents can be used as the liquid carrier in the adhesives of the present disclosure.

[0055] In some embodiments of the adhesive of the present disclosure, the liquid carrier includes at least one of a methylated siloxane, a ketone or ester each having up to six carbon atoms, a halogenated alkane having up to two carbon atoms, tetrachloroethylene, 1-chloro-4-trifluoromethylbenzene, or ethane. Certain of these solvents are listed as exempt VOCs in the California Consumer Products Regulations, Section 8.5, Subsection 2, 94508 (Register 2014, No. 38) and the California Air Resources Board, revised September 17, 2014. A complete list of VOC exempt solvents maintained by the US Environmental Protection Agency can be found at epa.gov / ground-level-ozone-pollution / complete-list-voc-exemption-rules. Examples of suitable ketones having up to six carbon atoms include acetone, methyl ethyl ketone, and methyl butyl ketone. Examples of suitable esters having up to six carbon atoms include methyl acetate, ethyl acetate, propyl acetate, and butyl acetate (e.g., n-butyl acetate and t-butyl acetate). In some embodiments, the liquid carrier is non-fluorinated, and in some embodiments, is non-halogenated. In some embodiments of the adhesive of the present disclosure, the liquid carrier includes at least one of acetone, methyl acetate, methyl formate, or t-butyl acetate. In some embodiments of the adhesive of the present disclosure, the liquid carrier includes at least one of acetone, methyl acetate, or t-butyl acetate. In some embodiments, the liquid carrier includes at least one of acetone or methyl acetate.

[0056] The adhesive can be provided in water or a solvent, for example, by dissolving the block copolymer, terpene resin, and polyphenylene ether resin as described above in any of its embodiments, in a liquid carrier, for example, any of those described above, using standard mixing equipment. The adhesive can be used as a spray adhesive and / or coated onto a backing or other substrate, and the coated product dried or allowed to dry to remove the liquid carrier.

[0057] In some embodiments, the adhesives of the present disclosure are useful as spray adhesives. In spray adhesives, the liquid carrier can evaporate at or after spraying, and the adhesive can develop adhesive properties as the liquid carrier evaporates. For example, spray adhesives can be useful as PSAs or contact adhesives, and the time required before bonding can be adjusted by changing the adhesive formulation, including the liquid carrier. Solvent-based spray adhesives can require only seconds or minutes before bonding, and can require a working time of several minutes to make adhesive bonds. In some embodiments of the adhesives and methods of the present disclosure, including those in which the ratio of terpene resin to block copolymer is greater than 1 : 1 or at least 1.5: 1, 1.6: 1, 1.7: 1, or 1.9: 1, the adhesive has only pressure-sensitive adhesive properties (e.g., tack) when at least a portion of the liquid carrier is present.

[0058] In some embodiments, the spray adhesives include a propellant. Examples of suitable propellants include nitrogen, carbon dioxide, ethane, propane, isobutane, n-butane, dimethyl ether, 1,1-difluoroethane, trans-1,3,3,3-tetrafluoropropene, and mixtures thereof. In some embodiments, the adhesives of the present disclosure are in the form of an aerosol. In aerosols, the propellant typically includes at least one of propane, isobutane, butane, dimethyl ether, or 1,1-difluoroethane. Typically, liquid aerosol propellants such as propane, butane, and isobutane are added to the adhesive in amounts ranging from about 5 wt% to about 40 wt%, 10 wt% to 30 wt%, 10 wt% to 25 wt%, or 15 wt% to 25 wt%, based on the total weight of the adhesive. Propane suitable for use as an aerosol propellant is commercially available under the trade designation “A-110” from Technical Propellants, Inc. When gases such as nitrogen and carbon dioxide are used as propellants, the gas propellant is typically present in amounts ranging up to about 10 wt%, 8 wt%, 6 wt%, 5 wt%, or 2 wt%, based on the total weight of the composition. In some embodiments, the propellant is non-fluorinated, in some embodiments, non-halogenated. In some embodiments, the propellant is propane, isobutane, butane, isopentane, dimethyl ether, or a combination of any two or more of these. For combinations of any two of propane, isobutane, butane, isopentane, dimethyl ether, the ratio of the two can be 5:95, 10:90, 15:85, 20:80, 25:75, 30:70, 35:65, 40:60, 45:55, or 50:50.

[0059] In some embodiments, the adhesive of the present disclosure comprises no more than 40, 30, 29, or 20 weight percent of non-VOC exempt non-aromatic non-halogenated hydrocarbon solvents, propellants, and combinations thereof, based on the total weight of the adhesive. The term "hydrocarbon" refers to compounds having only carbon and hydrogen atoms, and includes any of the compounds listed above that are not typically VOC exempt. In some embodiments, the adhesive of the present disclosure comprises at least 0.5, 1, 5, 10, 15, or 20 weight percent of non-VOC exempt non-aromatic non-halogenated hydrocarbon solvents, propellants, and combinations thereof, based on the total weight of the adhesive. In some embodiments, the adhesive of the present disclosure comprises 30 to 75, or 50 to 70 weight percent of a VOC exempt liquid carrier, including any of those described above, based on the total weight of the adhesive. In some embodiments, the VOC exempt liquid carrier is not fluorinated. In some embodiments, the VOC exempt liquid carrier is not halogenated. In some embodiments, the VOC exempt liquid does not contain siloxane bonds. In some embodiments, the VOC exempt liquid carrier includes at least one of acetone, methyl acetate, methyl formate, or t-butyl acetate.

[0060] In some embodiments, the adhesives of the present disclosure and / or useful in practicing the present disclosure are packaged in a spray container. Any of a variety of different spray containers can be used to deliver the adhesives of the present disclosure and in methods of using the adhesives or in methods of making bonded articles according to the present disclosure.

[0061] In some embodiments, the spray container is an aerosol can. Aerosol cans can be obtained from a variety of sources, for example, from Ball Metalpack, Broomfield, Colorado, under the trade designation "Classic Tinplate Can." Any aerosol actuator (for example, obtained from Aptar, Mukwonago, Wisconsin, under the trade designation "Seaquist 802-24-20 / 0890-20FS" with a color change valve obtained from Aptar under the trade designation "AR-83") can be useful.

[0062] In some embodiments, the spray container is an air-assisted spray system. Examples of useful air-assisted spray systems include those available under the trade designations “3M Accuspray ONE Spray Gun System with Standard PPS” and “3M Accuspray Paint Spray System with PPS 2.0” from 3M Company, St. Paul, Minnesota. Thus, the spray container can be a disposable cup or cup and disposable liner attached to a spray gun having an atomizing head or nozzle. Compressed air can be used, for example at a pressure in the range of 0.13 megapascals (MPa) to 0.21 MPa.

[0063] In other embodiments, an airless spray system can be useful with the adhesives and methods of the present disclosure. A pressure tank, such as a one liter volume tank with a pressure of up to 225 psi (1.24 MPa), available from, for example, Apache Stainless Steel Equipment Corporation, Beaver Dam, Wisconsin, can be connected to a nylon hose, for example, available under the trade designation “3M Cylinder Adhesive Hose” from 3M Company, St. Paul, Minnesota. The hose can be, for example, up to 8 meters, 7 meters, 6 meters, 5 meters, 4 meters, 3 meters, 2 meters, or 1 meter in length. A high throughput metal spray gun, for example, available under the trade designations “GunJet” and “H GunJet” from Spray Systems Co., Minnetonka, Minnesota, having, for example, brass tips available under the trade designations “4001 UniJet,” “6501 UniJet,” “9501 UniJet,” “1100050 UniJet,” and “800050 UniJet” from Spray Systems Co., can be conveniently attached to the hose. The tank can be pressurized with dry nitrogen or any desired gas.

[0064] A method for manufacturing a bonded article comprising a first substrate or a second substrate according to the present disclosure includes spraying the adhesive of the present disclosure on at least one of the first substrate or the second substrate. The method further includes adhering the first substrate and the second substrate together using the adhesive. In some embodiments, the method further includes evaporating a portion of the liquid carrier prior to adhering the first substrate and the second substrate. The present disclosure provides an article comprising a first substrate and a second substrate bonded together with the adhesive of the present disclosure. The surface of the first substrate and the second substrate can be any desired material. In some embodiments, at least one of the surface of the first substrate or the surface of the second substrate comprises at least one of a metal, a glass, a polymer, a paper, a painted surface, a nonwoven or woven fabric, a composite material, or a wood. The material of the surface of the first substrate and the second substrate can be found throughout the substrate, or the surface can comprise a different material than the bulk of the substrate. In some embodiments, the surface of the first substrate and / or the second substrate comprises at least one of a metal (e.g., steel, stainless steel, or aluminum), a glass (e.g., which can be coated with indium tin oxide), a polymer (e.g., a plastic, a rubber, a thermoplastic elastomer, or a thermoset), a paper, a painted surface, or a composite material. A composite material can be made from any two or more constituent materials having different physical or chemical properties. When the components are combined to make a composite material, a material having properties different from the individual components is typically obtained. Some examples of useful composite materials include fiber-reinforced polymers (e.g., carbon fiber-reinforced epoxy resins and glass-reinforced plastics), metal matrix composites, and ceramic matrix composites. The surface of at least one of the first substrate or the second substrate can comprise a polymer such as a polyolefin (e.g., polypropylene, polyethylene, high-density polyethylene, polypropylene blends), polyamide 6 (PA6), acrylonitrile butadiene styrene (ABS), polycarbonate (PC), PC / ABS blends, polyvinyl chloride (PVC), polyamide (PA), polyurethane (PUR), thermoplastic elastomer (TPE), polyoxymethylene (POM), polystyrene, polyester (e.g., polyethylene terephthalate), poly(meth) methacrylate (PMMA), and combinations thereof. The surface of at least one of the first substrate or the second substrate can also comprise a metal coating on such a polymer. In some embodiments, at least one of the first substrate or the second substrate comprises a transparent material such as a glass or a polymer (e.g., acrylic or polycarbonate).

[0065] In some embodiments, at least one of the first substrate or the second substrate has a textured surface. Textured surfaces are common in construction. In some embodiments, at least one of the first substrate or the second substrate is a fibrous substrate or a foam substrate (e.g., a polymeric foam such as a polyurethane, EPDM, and a polyethylene foam).

[0066] Cellulosic substrates include woven or nonwoven fabrics. The term "nonwoven" refers to materials having a structure of individual fibers or filaments that are interlaced, but not in an identifiable manner as in a knitted fabric. Examples of nonwoven webs include spunbond webs, hydroentangled webs, needlepunched webs, airlaid webs, meltblown webs, and bonded carded webs. Useful nonwovens can be made from natural fibers (e.g., wood fibers or cotton fibers), synthetic fibers (e.g., thermoplastic fibers), or a combination of natural and synthetic fibers. Examples of suitable materials for forming thermoplastic fibers include polyolefins (e.g., polyethylene, polypropylene, polybutylene, ethylene copolymers, propylene copolymers, butylene copolymers, and copolymers and blends of these polymers), polyesters, and polyamides. The fibers can also be multicomponent fibers, for example, having a core of one thermoplastic material and a sheath of another thermoplastic material. Examples of woven fabrics include twills and canvases.

[0067] In some embodiments, at least one of the first substrate or the second substrate is a low surface energy substrate. The term "low surface energy substrate" refers to those substrates having a surface energy of less than 34 dynes / cm. Included among such materials are 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). In some embodiments, at least one of the first substrate or the second substrate is a medium surface energy substrate. The term "medium surface energy substrate" refers to those substrates having a surface energy in the range of 34 dynes / cm to 70 dynes / cm, typically 34 dynes / cm to 60 dynes / cm, and more typically 34 dynes / cm to 50 dynes / cm. Such materials include polyamide 6 (PA6), acrylonitrile butadiene styrene (ABS), polycarbonate (PC) / ABS blends, PC, PVC, polyamide (PA), polyurethane (PUR), thermoplastic elastomer (TPE), polyoxymethylene (POM), polystyrene, and poly(methyl methacrylate) (PMMA). Surface energy is typically determined by contact angle measurements as described in, for example, ASTM D7490-08.

[0068] The adhesives of the present disclosure can be used in a variety of applications. The compositions of the present disclosure can also be used to bond different materials together. In some of these embodiments, the first substrate comprises a metal and the second substrate comprises a rubber or a plastic. In some embodiments, the first substrate and the second substrate are dissimilar plastics. The compositions of the present disclosure can also be used in foam lamination, where the first substrate or the second substrate is a foam (e.g., a polymeric foam such as polyurethane, EPDM, and polyethylene foam). The compositions of the present disclosure can also be used in packaging, where the first substrate or the second substrate is paper (e.g., paper coated with a polymer), paperboard, or wood.

[0069] In some embodiments, the adhesive of the present disclosure can be used in a tape and disposed on a tape backing. Accordingly, in some embodiments, the present disclosure provides a tape comprising the adhesive of the present disclosure as described above in any of its embodiments. As described above, the adhesive of the present disclosure can be coated on a tape backing and dried or allowed to dry to provide a tape. The tape backing can be any polymeric film material, paper, or polymeric cloth laminate. Suitable polymeric materials for the backing include polyesters (e.g., poly(ethylene terephthalate)); polyolefins (e.g., polyethylene, polypropylene); ethyl cellulose films; cellulose esters (e.g., cellulose acetate, cellulose acetate butyrate, and cellulose propionate); polyvinylidene chloride-vinyl chloride and / or acrylonitrile polymers such as Saran; vinyl chloride polymers (e.g., poly(vinyl chloride) and copolymers of vinyl chloride with vinyl acetate); polyvinylfluorides (e.g., polytetrafluoroethylene and polytrifluorochloroethylene); polyvinyl alcohol; polyamides such as nylon; polystyrenes such as copolymers of styrene and isobutylene; regenerated cellulose; benzyl cellulose; nitrocellulose; gelatin; glycol cellulose; flexible acrylate and methacrylate; urea-formaldehyde films; polyvinyl acetal; and polyvinyl butyral. The adhesive can be present on the tape backing in any useful amount, for example, in the range of 20 grams per square meter (gsm) to 150 gsm. For paper and polymeric film backings, the adhesive can be present in a useful amount of, for example, 20 gsm to 60 gsm, 20 gsm to 40 gsm, or 40 gsm to 60 gsm. For polymeric / cloth laminates, the adhesive can be present in a useful amount of, for example, 80 gsm to 150 gsm.

[0070] In some embodiments, the polymeric film tape backing of the tape is surface treated prior to application of the adhesive. Useful surface treatments include electrical discharge (e.g., plasma, glow discharge, corona discharge, dielectric barrier discharge, or atmospheric pressure discharge) in the presence of a suitable reactive or non-reactive atmosphere, ultraviolet light exposure, electron beam exposure, flame discharge, and abrasion. The surface treatment can be applied at the time of manufacture of the polymeric film backing or in a separate process. In some embodiments, the tape includes an optional low-adhesion backsize. Low-adhesion backsize known to those of ordinary skill in the art can be made from a variety of materials (e.g., silicone, fluorine-containing compound, or urethane).

[0071] In some embodiments, the adhesive is at least partially crosslinked by exposure to radiation, such as electron beam or ultraviolet radiation. Crosslinking can be performed in-line, continuously, or can be performed as a separate process. In some embodiments, crosslinking is performed after the adhesive is disposed on the backing. The degree of crosslinking achieved is a matter of choice and depends on various factors, such as the desired end product, the block copolymer used, and the thickness of the adhesive layer. Techniques to achieve crosslinking via exposure to radiation are known to those skilled in the art. Radiation crosslinking can enhance, for example, the cohesive strength of the adhesive.

[0072] Some embodiments of the present disclosure

[0073] In a first embodiment, the present disclosure provides an adhesive comprising a tackifying elastomer composition present in at least one of a form dissolved in a liquid carrier or a form dispersed in the liquid carrier, the tackifying elastomer composition comprising a block copolymer comprising at least one polystyrene end block, a terpene resin, and a polyphenylene ether resin. In a second embodiment, the present disclosure provides the adhesive of the first embodiment, wherein the block copolymer comprises at least one of a polystyrene-containing diblock copolymer, a polystyrene-containing triblock copolymer, or a polystyrene-containing star block copolymer, wherein the polystyrene-containing diblock copolymer, the polystyrene-containing triblock copolymer, and the polystyrene-containing star block copolymer each independently comprise blocks of at least one of polyisoprene, polybutadiene, poly(ethylene / propylene), poly(ethylene / butylene), or polyisobutylene. In a third embodiment, the present disclosure provides the adhesive of the first or second embodiment, wherein the terpene resin comprises an aromatic modified terpene resin. In a fourth embodiment, the present disclosure provides the adhesive of any one of the first through third embodiments, wherein the terpene resin comprises at least one copolymer of a terpene and a vinyl aromatic monomer. In a fifth embodiment, the present disclosure provides the adhesive of any one of the first through fourth embodiments, wherein the polyphenylene ether resin has a number average molecular weight of 300 grams / mole to 25,000 grams / mole. In a sixth embodiment, the present disclosure provides the adhesive of any one of the first through fifth embodiments, wherein the polyphenylene ether resin comprises at least one of poly(2,6-dimethyl-l,4-phenylene ether) or poly(p-phenylene ether). In a seventh embodiment, the present disclosure provides the adhesive of any one of the first through sixth embodiments, wherein the block copolymer comprises a diblock copolymer comprising a polystyrene block and a block of at least one of polyisoprene, polybutadiene, poly(ethylene / propylene), or poly(ethylene / butylene). In an eighth embodiment, the present disclosure provides the adhesive of any one of the first through seventh embodiments, wherein the block copolymer comprises a middle block and at least two polystyrene end blocks. In a ninth embodiment, the present disclosure provides the adhesive of any one of the first through eighth embodiments, wherein the block copolymer comprises at least one of a styrene-isoprene-styrene triblock copolymer or a styrene-butadiene-styrene triblock copolymer. In a tenth embodiment, the present disclosure provides the adhesive of any one of the first through ninth embodiments, wherein the tackifying elastomer composition further comprises ethylene-vinyl acetate.

[0074] In an eleventh implementation, the present disclosure provides the adhesive of any of the first through tenth implementations, wherein the liquid carrier comprises an organic solvent. In a twelfth implementation, the present disclosure provides the adhesive of any of the first through eleventh implementations, wherein the liquid carrier comprises a hydrocarbon solvent. In a thirteenth implementation, the present disclosure provides the adhesive of any of the first through tenth implementations, wherein the liquid carrier comprises at least one of a methylated siloxane, a ketone or ester each having up to six carbon atoms, a halogenated alkane having up to two carbon atoms, tetrachloroethylene, 1-chloro-4-trifluoromethylbenzene, or ethane. In a fourteenth implementation, the present disclosure provides the adhesive of any of the first through thirteenth implementations, wherein the liquid carrier comprises at least one of acetone, methyl acetate, methyl formate, or t-butyl acetate. In a fifteenth implementation, the present disclosure provides the adhesive of any of the first through fourteenth implementations, wherein the liquid carrier comprises at least one of acetone and methyl acetate. In a sixteenth implementation, the present disclosure provides the adhesive of any of the first through fifteenth implementations, wherein the adhesive comprises 30 to 75 weight percent of a non-halogenated VOC exempt solvent. In a seventeenth implementation, the present disclosure provides the adhesive of any of the first through sixteenth implementations, wherein the adhesive comprises 30 to 75 weight percent of acetone, methyl acetate, methyl formate, t-butyl acetate, or a combination thereof, based on the total weight of the adhesive. In an eighteenth implementation, the present disclosure provides the adhesive of any of the first through seventeenth implementations, not more than 40 weight percent of one or more of a non-aromatic non-halogenated hydrocarbon solvent, a propellant, and a combination thereof, based on the total weight of the adhesive, wherein the non-aromatic non-halogenated hydrocarbon solvent is not VOC exempt.

[0075] In a nineteenth implementation, the present disclosure provides the adhesive of any of the first through eighteenth implementations, wherein a weight ratio of the terpene resin to the block copolymer is greater than 1 : 1. In a twentieth implementation, the present disclosure provides the adhesive of any of the first through nineteenth implementations, wherein a weight ratio of the terpene resin to the block copolymer is at least 1.5: 1, 1.6: 1, 1.7: 1, or 1.9: 1. In a twenty-first implementation, the present disclosure provides the adhesive of any of the first through twentieth implementations, wherein a weight ratio of the block copolymer to the polyphenylene ether resin is in a range of 3: 1 to 25: 1. In a twenty-second implementation, the present disclosure provides the adhesive of any of the first through twenty-first implementations, wherein the block copolymer is present in an amount of 20 weight percent to 59 weight percent, the terpene resin is present in an amount of 40 weight percent to 75 weight percent, and the polyphenylene ether resin is present in an amount of 1 weight percent to 20 weight percent, based on a total weight of the tackified elastomer composition. In a twenty-third implementation, the present disclosure provides the adhesive of any of the first through twenty-second implementations, wherein the block copolymer comprises a styrene-diene-styrene triblock copolymer and a styrene-isoprene-styrene triblock copolymer in a weight ratio of at least 1 : 1, 2: 1, 3: 1, 4: 1, 5: 1, or 10: 1, and at most 25: 1, 20: 1, 10: 1, or 5: 1.

[0076] In a twenty-fourth implementation, the present disclosure provides the adhesive of any of the first through twenty-third implementations, further comprising a propellant. In a twenty-fifth implementation, the present disclosure provides the adhesive of the twenty-fourth implementation, wherein the propellant comprises at least one of nitrogen, carbon dioxide, ethane, propane, isobutane, n-butane, dimethyl ether, 1,1-difluoroethane, or trans- 1,3,3,3-tetrafluoropropene. In a twenty-sixth implementation, the present disclosure provides the adhesive of the twenty-fifth implementation, wherein the propellant comprises at least one of propane, isobutane, dimethyl ether, or 1,1-difluoroethane. In a twenty-seventh implementation, the present disclosure provides the adhesive of the twenty-sixth implementation, wherein the propellant comprises at least one of propane, isobutane, or dimethyl ether. In a twenty-eighth implementation, the present disclosure provides the adhesive of any of the first through twenty-fourth implementations or the twenty-seventh implementation, wherein the adhesive is free of fluorinated solvents and fluorinated propellants. In a twenty-ninth implementation, the present disclosure provides the adhesive of any of the first through twenty-eighth implementations, wherein the adhesive is stable at 48°C for at least two weeks, as determined according to a temperature ramp on a rheometer.

[0077] In a thirtieth embodiment, the present disclosure provides a method for manufacturing a bonded article comprising a first substrate and a second substrate, the method comprising spraying the adhesive of any one of the first through twenty-ninth embodiments on at least one of the first substrate or the second substrate, and adhering the first substrate and the second substrate using the adhesive. In a thirty-first embodiment, the present disclosure provides the method of the thirtieth embodiment, further comprising evaporating a portion of the liquid carrier prior to adhering the first substrate and the second substrate. In a thirty-second embodiment, the present disclosure provides use of the adhesive of any one of the first through twenty-ninth embodiments as a spray adhesive. In a thirty-third embodiment, the present disclosure provides the use of the thirty-second embodiment, wherein the tackified elastomer composition further comprises a thermoplastic plastic for enhancing a spray pattern. In a thirty-fourth embodiment, the present disclosure provides the use of the thirty-third embodiment, wherein the thermoplastic plastic is ethylene-vinyl acetate. In a thirty-fifth embodiment, the present disclosure provides the use of the thirty-fourth embodiment, wherein the ethylene-vinyl acetate is present in the tackified elastomer composition in an amount of 1 to 20 parts by weight or 5 to 15 parts by weight per 100 parts by weight of the block copolymer. In a thirty-sixth embodiment, the present disclosure provides use of the adhesive of any one of the first through twenty-ninth embodiments for manufacturing a tape. In a thirty-seventh embodiment, the present disclosure provides the adhesive of any one of the first through twenty-ninth embodiments disposed on a tape backing.

[0078] The following examples further illustrate embodiments of the compositions and methods disclosed herein, but the specific materials and amounts thereof mentioned therein and otherwise herein, as well as other conditions and details, should not be construed to unduly limit this application.

[0079] Examples

[0080] All parts, percentages, ratios, etc. in the examples and the rest of the specification are by weight, unless otherwise indicated. The following abbreviations are used in this section: g = grams, mg = milligrams, centimeters = cm, mm = millimeters, in. = inches, ft = feet, °C = degrees Celsius, °F = degrees Fahrenheit, phr = parts per hundred, wt% = weight percent, lb = pounds, g = grams, sec = seconds, oz = ounces, hr = hours, and min. = minutes.

[0081]

[0082]

[0083] Test methods

[0084] Rheological testing

[0085] Each of Examples 1-18 and Control Examples CEA-C EF (about 30 g) was poured or pipetted onto a 6-inch (15.2-cm) wide double-sided release liner (“Core Series” liner, available from 3M Company, St. Paul, MN), which was secured with tape and marked on a metal plate. The samples were allowed to sit at room temperature (72 °F, 22 °C) for about 2 hours to allow sufficient evaporation to permit easy transfer to an oven (“MODEL RFD2-13-2E” from Despatch ITW-EAE, Lakeville, MN). The entire metal plate with the adhesive and release liner attached was placed in a 120 °F (49 °C) oven for about 24 hours or until all of the solutions had evaporated and left a dry film of adhesive.

[0086] To help prepare a uniform film and reduce air bubbles in the film, the film was then folded and pressed to a thickness of 0.12 inch (3 mm). The dry film was folded over itself 4 times and then pressed into a thin film at 250 °F (121 °C) in a Carver press (Model C from Carver, Inc., Wabash, IN) at 10,000 pounds (4536 kg) using a metal support mold measuring 2 inch x 2 inch x 0.6 inch (5.08 cm x 5.08 cm x 1.5 mm) in the center for 30 seconds. This process was repeated so that the film sample was pressurized a total of 3 times in the Carver press, and each sample was folded over itself 4 times before each pressing. The mold and sample were removed from the Carver press and allowed to cool to room temperature (72 °F, 22 °C). The adhesive center was cut from the mold with the release liner still attached for ease of handling.

[0087] The samples were allowed to sit at room temperature (72 °F, 22 °C) for a minimum of 24 hours prior to measuring rheology. The samples were tested using an ARES-G2 rheometer with TRIOS software (available from TA Instruments, New Castle, DE) with 8-mm diameter samples, which had 8-mm disposable aluminum parallel plates attached to both the upper and lower stainless steel clamps. The “low and high temperature ramp” test method setting was used to measure tan delta (loss modulus / storage modulus or G” / G’, respectively) over a range of temperatures at a frequency of 1 Hz. The first ramp of the test was started at 50 °C, and the temperature was decreased at 3 °C / min until the defined tan delta peak (glass transition temperature (Tg)) was reached. The temperature was then increased at 3 °C / min until the tan delta peak was no longer observed. The temperature at which the tan delta peak was no longer observed was reported as the Tg.g The second ramp of the test included ramping the temperature from 50°C to 150°C at a rate of 3°C / min, or until the tan delta reached 2 units or more. A soak time of 180 seconds at 50°C was used prior to starting the first and second ramps. Automatic strain adjustment was enabled in the TRIOS software program file to ensure the material was in the linear viscoelastic region (LVR) during all temperature ramps. The results of the two ramps were combined to evaluate tan delta versus temperature at 1 Hz frequency. The results are presented in Table 5.

[0088] Preparation of samples for overlap shear (OLS), peel, and shear adhesion failure test

[0089] The following examples adhesives were applied with a 1-inch (2.54-cm) utility paint brush (1-inch (2.54-cm) synthetic bristles, available from Grainger, Lake Forest, IL) with a target wet coat weight of approximately 5 g / ft 2 to 7 g / ft 2 (5.4 mg / cm 2 to 7.5 mg / cm 2 ). Once the adhesive was applied to the substrate, the adhesive was bonded within 5 to 10 minutes. The samples were rolled together with a 1.75-inch (4.45-cm) wide rubber hand roller and clamped with adhesive clips for 16 to 24 hours before testing on a tensile tester (available under the trade designation "QTEST 5" from MTS Systems Corporation, Eden Prairie, MN). Lap shear samples were made on birch-birch samples that were 1.0 inch x 4.0 inch x 0.25 inch (2.54-cm x 10.2-cm x 0.64-cm) panels available from Forest Product Supply, St. Paul, MN. Peel and dead load samples were prepared on cotton canvas to cotton canvas that was 1.5 inch x 10.0 inch (3.81-cm x 25.4-cm) Greige Cotton #10 available from Canwil Textiles, Auburn, GA.

[0090] Overlap shear (OLS) and peel tests

[0091] Overlap shear strength was measured on a tensile tester (“QTEST 5” from MTS Systems Corp.) where the sample was stretched at a rate of 2.0 inches (5.08-cm) per minute. As described above, the break overlap shear strength of birch / birch OLS samples was recorded. The same tensile tester was used to determine the peel strength, stretching the cotton duck to cotton duck peel sample (as described above) at a rate of 2.0 inches (5.08-cm) per minute, for a total length of 4 inches (10.16 cm). Three samples were measured per test, and the average was taken. Overlap shear strength and peel strength were reported in pounds per inch width (PIW). Results are presented in Table 5.

[0092] Shear adhesion failure test (SAFT)

[0093] SAFT was performed by placing 1.0-in 2 (6.45-cm 2 ) area of bonded birch-birch OLS samples as described above into an oven (“MODEL RFD2-13-2E” from Despatch ITW-EAE of Lakeville, MN) and hanging a 100-g weight from the bottom of the birch-birch sample. The temperature of the oven started at 90 °F (32 °C) and was increased by 10 °F every ten minutes until the bond failed. The temperature at which the bond failed was recorded. Data was collected and recorded as an average of three samples, and results are presented in Table 5.

[0094] Static load testing

[0095] Static load measurements were obtained by placing the samples into the same oven described above. Static load testing was performed on the second half of the peel sample. One side of the cotton duck fabric was secured in the oven, and the other side was secured with a 500-g weight. The oven was set to a specific temperature depending on the adhesive, and the 500-g weight was hung for 60 minutes. For Examples 1-12 and CEA-D, the temperature was 160 °F (71 °C). For Examples 13-17, CEE, and CEF, the temperature was 120 °F (49 °C). The sample was removed from the oven and the total peel distance was measured. The average of three measurements was recorded and presented in Table 5.

[0096] Examples 1 to 5 (EX 1 to 5) and comparative examples (CE) A and B

[0097] The amounts of block copolymer, terpene resin, and polyphenylene ether resin used for EX 1 to EX 5 and CE A and CE B are shown in Table 2. EVA (12 phr, 0.92 wt%), UVA (1 phr, 0.08 wt%), stabilizer (0.5 phr, 0.04 wt%), AO2 (2 phr, 0.15 wt%), AO3 (2 phr, 0.15 wt%), cyclohexane (257 phr), n-pentane (60 phr), and methyl acetate (673 phr) were also used for each of EX 1 to EX 4 and CE A. EVA (12 phr, 0.92 wt%), UVA (1 phr, 0.08 wt%), stabilizer (0.5 phr, 0.04 wt%), AO1 (2 phr, 0.15 wt%), cyclohexane (257 phr), n-pentane (60 phr), and methyl acetate (673 phr) were also used for CE B and EX 5. A total of 300 g of all components were added to a metal pint can, and the mixture was placed on a can roll (commercial bottle roll from TDC / Technical Development Corporation of Huntersville, NC) for 24 to 48 hours.

[0098]

[0099] a Sum of all components.

[0100] Examples 6 to 12 (EX 6 to 12) and comparative examples CE C and CE D

[0101] The amounts of block copolymer, terpene resin, polyphenylene ether resin, and hydrocarbon resin for EX 6 to EX 12, CEC, and CED are shown in Table 3. In addition, each of EX 6 to EX 11 and CEC includes EVA (10 phr, 0.78 wt%), UVA (1 phr, 0.08 wt%), stabilizer (0.5 phr, 0.04 wt%), AO2 (2 phr, 0.16 wt%), AO3 (2 phr, 0.16 wt%), cyclohexane (245 phr), solvent A (31 phr), solvent B (31 phr), and methyl acetate (653 phr). EX 12 and CED, in turn, also include EVA (10 phr, 0.78 wt%), UVA (1 phr, 0.08 wt%), stabilizer (0.5 phr, 0.04 wt%), AO1 (2 phr, 0.16 wt%), cyclohexane (245 phr), solvent A (31 phr), solvent B (31 phr), and methyl acetate (653 phr). A total of 300 g of all components were added to a metal pint can, and the mixture was placed on a can roll as described in Examples 1 to 5, CEA, and CEB for 24 to 48 hours.

[0102]

[0103] Examples 13 to 17 (EX 13 to 17) and comparative examples CE E and CE F

[0104] The amounts of block copolymer, terpene resin, and polyphenylene ether resin for EX 13 to EX 17, CEE, and CEF are shown in Table 4. In addition, each of EX 13 to EX 16 and CEE includes EVA (10 phr, 1.14 wt%), UVA (1 phr, 0.11 wt%), AO2 (2 phr, 0.16 wt%), AO3 (2 phr, 0.16 wt%), reagent grade acetone (261 phr), cyclohexane (44 phr), solvent A (36 phr), n-pentane (134 phr), and methyl acetate (87 phr). EX 17 and CEF, in turn, also include EVA (10 phr, 1.14 wt%), UVA (1 phr, 0.11 wt%), AO2 (2 phr, 0.16 wt%), AO3 (2 phr, 0.16 wt%), reagent grade acetone (261 phr), cyclohexane (44 phr), solvent A (36 phr), n-pentane (134 phr), and methyl acetate (87 phr). A total of 300 g of all components were added to a metal pint can, and the mixture was placed on a can roll as described in Examples 1 to 5, CEA, and CEB for 24 to 48 hours.

[0105]

[0106] Example 18

[0107] A total of about 300 g of SIS (40 phr, 3.95 wt%), diblock (60 phr, 5.93 wt%), terpene (235 phr, 23.21 wt%), PPE1 (15 phr, 1.48 wt%), UVA (0.8 phr, 0.08 wt%), AO2 (1.5 phr, 0.15 wt%), AO3 (1.5 phr, 0.15 wt%), reagent grade acetone (30 phr, 2.96 wt%), cyclohexane (280 phr, 27.66 wt%), solvent A (50 phr, 4.94 wt%), reagent grade isohexane (150 phr, 14.82 wt%), and reagent grade heptane (150 phr, 14.82 wt%) were added to a metal quart can, and the mixture was placed on a tank roller as described in Examples 1-5, CEA, and CEB for 24-48 hours.

[0108] The above rheology, OLS, peel, SAFT, and dead load tests were performed on Examples EX 1-18 and CEA-F, and the results are shown in Table 5 below. Peak height is the height of the tan delta peak at T g “Extra peak” refers to the presence of an additional peak in addition to the tan delta peak at T g “Extra peak” refers to the presence of an additional peak in addition to the tan delta peak at T

[0109] Adhesive film samples prepared for rheology testing from Examples 2, 6, and 14 were placed in an oven (“MODEL RFD2-13-2E” from Despatch ITW-EAE) at 120 °F (49 °C) for two weeks, the rheology test was repeated, and only minor differences were observed in the rheology data, which were within experimental error.

[0110]

[0111] a Average of two measurements. b NM = not measured.

[0112] Examples 19 to 23 (EX 19 to 23) and comparative examples (CE) G and H

[0113] The components and amounts thereof for EX 19 to EX 23 and CE G and CE H are shown in Table 6. A total of 300 g of all components were added to a metal pint jar and the mixture was placed on the jar roller described in Examples 1 to 5, CE A and CE B for 24 to 48 hours. The above rheology tests were performed on Examples EX 19 to 23 and CEs G and H and the results are shown in Table 6 below. Peak height is the height of the tan delta peak at T g “Extra peak” refers to the presence of an additional peak in addition to the tan delta peak at T g “Extra peak” refers to the presence of an additional peak in addition to the tan delta peak at T

[0114]

[0115] a The solvent is a mixture of one or more non-aromatic non-halogenated hydrocarbon solvents of VOC exempt solvents and no more than 40 weight percent of non-aromatic non-halogenated hydrocarbon solvents based on the total weight of the adhesive.

[0116] Various modifications and changes in light thereof can be made by those skilled in the art without departing from the scope and spirit of the disclosure, and it is understood that the present disclosure is not to be unduly limited to the illustrative embodiments set forth herein.

Claims

1. An adhesive comprising a tackifying elastomeric composition present in at least one of a form dissolved in a liquid carrier or a form dispersed in a liquid carrier, the tackifying elastomeric composition comprising: a block copolymer comprising at least one polystyrene end block; a terpene resin; and a polyphenylene ether resin.

2. The adhesive of claim 1, wherein the block copolymer comprises at least one of a polystyrene-containing diblock copolymer, a polystyrene-containing triblock copolymer, or a polystyrene-containing star block copolymer, wherein the polystyrene-containing diblock copolymer, the polystyrene-containing triblock copolymer, and the polystyrene-containing star block copolymer each independently comprises blocks of at least one of polyisoprene, polybutadiene, poly(ethylene / propylene), poly(ethylene / butylene), or polyisobutylene.

3. The adhesive of claim 1 or 2, wherein the block copolymer comprises at least one of a styrene-isoprene-styrene triblock copolymer or a styrene-butadiene-styrene triblock copolymer.

4. The adhesive of any one of claims 1 to 3, wherein the terpene resin comprises an aromatic modified terpene resin.

5. The adhesive of any one of claims 1 to 4, wherein the terpene resin comprises at least one copolymer of a terpene and a vinyl aromatic monomer.

6. The adhesive of any one of claims 1 to 5, wherein the liquid carrier comprises an organic solvent.

7. The adhesive of any one of claims 1 to 6, wherein the liquid carrier comprises at least one of a hydrocarbon solvent, acetone, methyl acetate, methyl formate, or t-butyl acetate.

8. The adhesive of any one of claims 1 to 7, wherein the adhesive comprises 30 to 75 weight percent of acetone, methyl acetate, methyl formate, t-butyl acetate, or a combination thereof, and no more than 40 weight percent, based on weight, of one or more of a non-aromatic non-halogenated hydrocarbon solvent, a propellant, and a combination thereof, based on the total weight of the adhesive.

9. The adhesive of any one of claims 1 to 8, wherein a weight ratio of the terpene resin to the block copolymer is greater than 1 :

1.

10. The adhesive of any one of claims 1 to 9, wherein the weight ratio of the terpene resin to the block copolymer is at least 1.5:

1.

11. The adhesive of any one of claims 1 to 10, wherein a weight ratio of the block copolymer to the polyphenylene ether resin is in a range of 3: 1 to 25:

1.

12. The adhesive of any one of claims 1 to 11, further comprising a propellant.

13. The adhesive of any one of claims 1 to 12, wherein the adhesive is stable at 48°C for at least two weeks, as determined according to a temperature ramp on a rheometer.

14. A method of manufacturing a bonded article comprising a first substrate and a second substrate, the method comprising: applying the adhesive according to any one of claims 1 to 13 to at least one of the first substrate or the second substrate; and adhering the first substrate and the second substrate using the adhesive.

15. Use of the adhesive according to any one of claims 1 to 13 as a spray adhesive.

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