Methods and compositions for adhesion to low surface energy materials

Abstract

A two-component adhesive composition for bonding a low surface energy polymer to a substrate material, the adhesive comprising: component A, which includes one or more of an epoxy having at least two epoxy groups per molecule or a reaction product of an epoxy with a thiol, phenol or carboxylic acid-functional species; and component B, which includes a reaction product of an epoxy with a thiol, phenol or carboxylic acid-functional species, wherein the thiol, phenol or carboxylic acid-functional species contains at least two functional SH, OH or COOH groups capable of reacting with the epoxy species.

Description

Technical Field

[0001] The present teachings generally relate to bonding low surface energy polymeric materials (e.g., copolymers, terpolymers, etc.) to substrates. The low surface energy polymeric material may be ethylene vinyl acetate or any other copolymer or terpolymer material, particularly those based on olefin chemistry. The substrate may also be a polymeric material, which may be a polyurethane material, natural or synthetic leather, or a natural or synthetic fiber. Background Art

[0002] Some challenges exist in adhering materials to low surface energy materials (e.g., surface free energy of 35 dynes / cm 2 The following materials). These materials can have low surface energy inherently, or can be processed so that they have low surface energy. Specifically, some low surface energy copolymers or terpolymer materials (which can be foam and / or ethylene-based low surface energy materials) commonly used in a variety of goods including shoes, ski boots, bicycle saddles, hockey pads, boxing gloves and helmets, water ski boots, fishing rods and fishing reel handles, orthotics, surfboards and shallow water water ski traction pads and similar products have brought great challenges to sufficient adhesion. A part of these uses requires that the low surface energy copolymer material is adhered to one or more additional materials with significant polarity, surface energy or morphology differences. In many cases, an organic primer layer is deposited on the substrate so as to be bonded together before the adhesive material is deposited. The primer can be an organic solvent-based or water-based solution, dispersion or suspension. The organic primer layer helps to improve the durability and reliability of the bonded material joint by providing an adhesive that can be more easily adhered to the surface thereon, and provides a reliable adhesive material joint. The primer layer can also help to widen the purposes of the adhesive, allowing it to be used for bonding a variety of substrates together.

[0003] After the primer deposition step, there are additional process steps that can be required to activate or dry the primer layer. These process steps can include exposure to elevated temperatures or electromagnetic radiation (i.e., UV- or IR-induced curing steps). The additional process steps associated with handling, applying, and drying or activating the primer layer introduce complexity and cost into the manufacturing assembly process. If the primer contains volatile organic compounds (VOCs), there may also be worker safety issues and environmental issues associated with the use of the primer material.

[0004] U.S. Pat. No. 5,143,999 describes adhesive compositions and injection compositions including epoxy compounds in combination with dithiols and amines for sealing. However, the use of pre-reacted components used in combination with additional epoxy compounds or dithiols for adhesion to low surface energy materials has not been addressed.

[0005] In one specific example, low surface energy copolymers are widely used in shoemaking, and it is necessary to bond the low surface energy copolymer to a second material such as synthetic leather, polyurethane or synthetic fabric as part of the shoemaking process. In order to prepare a strong shoe assembly, the current state of the art of existing adhesives requires that the adhesive be applied to both surfaces to be bonded after the primer is deposited on both substrates as described above. The deposition of the adhesive on both surfaces to be joined creates additional process complexity. It is therefore desirable to provide such an adhesive that can be applied to only one surface to be joined, preferably a low surface energy copolymer, and bond the low surface energy copolymer to a variety of materials while potentially eliminating the primer layer and its associated manufacturing steps. Summary of the invention

[0006] The present teachings relate to a method for adhering a low surface energy copolymer (any use of the term copolymer herein also includes terpolymers) and a substrate to bond the low surface energy copolymer and the substrate together. The method can include treating the surface of the low surface energy copolymer using an automated process prior to deposition of the adhesive, which may be, but is not limited to, plasma, thermal, corona or flame treatment; mixing a first component with a second component to form a fully formulated adhesive material, applying the mixed adhesive to the surface of the low surface energy copolymer; and thermally activating the adhesive immediately prior to contact with the substrate to adhere the low surface energy copolymer to the substrate. It is possible that the adhesive can be placed on the substrate immediately after mixing, or alternatively placed on the substrate while the molecular weight of the mixed composition increases before being applied to the substrate.

[0007] The first component and the second component of the adhesive composition can each contain numerous components, and the components can be partially selected from one or more of epoxy, one or more of dithiols, one or more of the reaction products between epoxy and dithiols, one or more reaction catalysts, and optionally one or more amines. The bonding method preferably does not contain any step involving the application of primer to the low surface energy copolymer. After the application of the adhesive component, the low surface energy copolymer can be adhered to the substrate. It is typically desirable to minimize the assembly time. It may be necessary to produce enough adhesive strength by mixing the adhesive composition formed by the two components to prevent or immediately after the assembly process or in a long period of time from the assembly layer being bonded. Delamination can be prevented substantially at a temperature of up to about 176 ° F from room temperature. The bonding process can occur after the adhesive composition is dripped onto the low surface energy copolymer (in some cases, more than one hour after being deposited onto the low surface energy copolymer). Advantageously, before assembly, the adhesive material can also quickly produce a dry-to-touch characteristic at room temperature, which can be accelerated by the thermal regulation of the adhesive dripped.

[0008] The first component can be an epoxy composition. The epoxy composition can partially pre-react with two-thiol, amine or another functional material or another molecule that each molecule mainly contains two reactive hydrogens. The second component can be a thiol-based composition containing or not containing reactive amines. The thiol composition can partially pre-react with one or more di-functional epoxy resins. The first component and the second component can be in a paste or liquid or semi-liquid form at room temperature.

[0009] The low surface energy copolymer surface may be treated prior to application of the first component, the second component, or some combination thereof, which may be, but is not limited to, heat treatment, plasma treatment, or flame treatment.

[0010] Under suitable dripping conditions, the viscosity of the first component, the second component or the resulting adhesive can be at least about 10,000 to 400,000 Pa·s. Before the low surface energy copolymer is contacted with the substrate, the adhesive can be dripped onto the low surface energy copolymer. The low surface energy copolymer can be adhered to the substrate without directly dripping any adhesive onto the substrate. The first component, the second component and the adhesive can be substantially free of any volatile organic compounds (VOCs). The first component and the second component can react when in contact with each other, whether heated or not. The bonding method can include applying pressure to adhere the substrate to the low surface energy copolymer. The adhesive can have a sufficiently high viscosity so that when applied to the low surface energy copolymer, it is not substantially spread on the substrate from its original dripping position under normal substrate handling conditions. The method can be free of applying any primer to the low surface energy copolymer or substrate. The low surface energy copolymer can be the midsole of a shoe. The substrate can be the upper part of a shoe (e.g., strobel). The adhesive can be free of free isocyanate. DETAILED DESCRIPTION

[0011] This teaching satisfies one or more of the above needs by the improved device and method described herein. The explanation and diagram presented herein are intended to make those skilled in the art understand teaching, its principle and its practical application. Those skilled in the art can adjust and apply the teaching in its many forms, and these forms can be most appropriately suitable for the requirements of practical application. Accordingly, the teaching specific embodiments illustrated are not intended to be exhaustive or teaching limitations. Therefore, the scope of teaching should not be determined with reference to the above description, but should be determined with reference to the complete scope of the equivalents assigned to the attached claims and this claim instead. All articles and the disclosure of the references including patent applications and patent publications are incorporated by reference for all purposes. Other combinations collected by the following claims are also possible, and they are also hereby incorporated by reference in this written specification.

[0012] The teachings herein are directed to the use of adhesives that may be two-component adhesives capable of adhering to certain materials that typically pose adhesion challenges. More specifically, the adhesives herein may be capable of in-situ polymerization on the surface of a low surface energy copolymer / terpolymer when combining the first component and the second component of the adhesive prior to or concurrently with application to the low surface energy copolymer and / or substrate for adhering to the low surface energy copolymer.

[0013] After applying the adhesive components to the low surface energy copolymer surface, it is possible that, prior to assembly, the adhesive polymerization can be driven by a stimulus, which can be a physical stimulus such as heat. It is also possible that the adhesive can be polymerized at room temperature without heating before being attached to a second surface (e.g., a substrate), which can be a second polymeric surface, specific examples of which include polyester-, polyamide-, polyurethane-based or other materials.

[0014] It may be desirable that the viscosity of the adhesive (or each component of the adhesive) be low enough so that it can be sprayed, dripped, spread, brushed or otherwise applied to a surface in a uniform layer, but high enough so that it does not flow over the edges of the surface under room temperature factory conditions. In some cases, it may be useful for the polymerization to further develop a structure that enables the adhesive to have sufficient structure to resist undesired movement of the adhesive after assembly.

[0015] The first and second components used to form the adhesive can be selected so that the molecular weight of the resulting adhesive is increased, but crosslinking of the adhesive is kept to a minimum. Even a small increase in reactive functionality will generally result in this undesirable degree of crosslinking, particularly if the monomers of the first component and the monomers of the second component are at or near a stoichiometric ratio.

[0016] The adhesive may be described as a reactive two-component adhesive paste that forms a thermoplastic polymer by an in-situ reaction when the two components of the co-reactive composition are mixed and deposited onto a substrate. The in-situ reaction may occur at room temperature (-20-25°C) and may progress over a period of hours or even days to form a thermoplastic polymer. The polymer formed by the in-situ reaction may be thermoplastic (i.e., primarily linear, capable of softening by exposure to elevated temperatures). The reactive monomers that form the thermoplastic polymer may be di-functional, or at least primarily di-functional.

[0017] Adhesive can be a two-component adhesive, which includes component A and component B. Component A can include thermoplastic prepolymers, which are end-capped with unreacted epoxy functional groups. Component A can also include unreacted epoxy resins, which are not chemically bonded to thermoplastic prepolymers. The component B of adhesive composition can include low molecular weight thermoplastic prepolymers, which are end-capped with unreacted nucleophilic groups that can react with epoxy functional groups. Component B can also include unreacted nucleophilic species, which are not chemically bonded to prepolymers. Component A and component B can utilize conventional methods (for example, by independent box or via dual metering system) to mix and drip. The presence of low molecular weight thermoplastic polymers can improve the immature state (for example, before solidification) intensity of adhesive bonding.

[0018] After the two components are dripped onto one or more of the surfaces to be joined, the adhesive can develop a dry-to-the-touch property at room temperature (approximately 20° C.). It is possible that the development of the dry-to-the-touch property can be accelerated by simple exposure to elevated temperatures. Once the components are dripped onto the first surface, the adhesive can remain in a dry state on the substrate until a later time when it is brought into contact with the second surface to form an adhesive joint (e.g., the applied adhesive can have an extended shelf life). Prior to contact with the second surface to be joined, the adhesive can be activated (e.g., possibly by an external stimulus) to raise the adhesive to a temperature at which it adheres and / or cures. Once the bonded joint is formed, the adhesive continues to react at a temperature at (or above) room temperature to form a high molecular weight thermoplastic polymer. The adhesive can remain thermoplastic, or alternatively can start as a thermoplastic, but eventually become a thermosetting material.

[0019] One or more components of the adhesive may include reactive epoxies such as chemically modified liquids, bisphenol A diglycidyl ether. One or more components may include particulate materials that can modify the physical properties of the adhesive material. Such particles may be, for example, fumed silica or modified layered silicates. One or more components of the adhesive may include monofunctional primary amines, such as monoethanolamine, furfurylamine, octylamine, or octadecylamine. One or more of the adhesive components may include an odor masking agent, which may be, but is not limited to, zinc ricinoleate. One or more of the adhesive components may include thiols or dithiols, which may be, but are not limited to, ethylene glycol-bis(3-mercaptopropionate), 1,8-dimercapto-3,6-dioxaoctane, or other thioethers. One or more of the components may also include a thiol-epoxy reaction catalyst, such as benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, or triphenylphosphine. One or more of the components may include secondary di-amines.

[0020] One or more of the ingredients may include a functionalized compound, which can be, but is not limited to, a functionalized liquid elastomer or a functionalized polyether. The functional group may be a carboxyl group (COOH), a thiol (SH) or an amine (NH or NH2). The number of functional groups per molecule is preferably two, and the number of active hydrogens per molecule that can react with epoxy functional groups is preferably two or more. The component can be a butadiene homopolymer or a butadiene-acrylonitrile copolymer with a functional group at the end of the chain. The component can also be ethoxylated-trimethylolpropane tris (3-mercaptopropionate).

[0021] One or more of the adhesive ingredients may be comprised of a pre-reaction product between two or more of the components described herein.

[0022] Described composition and / or resulting tackiness agent can be applied to low surface energy copolymer substrate in such form, described form is liquid-like yet viscosity is high enough to remain on the surface and does not have obvious flow.Alternatively, composition and / or resulting tackiness agent can be placed on the surface in pasty form.The resulting tackiness agent can be a thermoplastic material (referring to Table 1, embodiment 1), but can also be a thermosetting material (referring to Table 1, embodiment 2 and 3).It can be after deposition, for example after deposition more than one day, forms thermosetting thermoplastic material.When low surface energy copolymer is adhered to required substrate, tackiness agent can be enough flexible and firm, makes when low surface energy copolymer material and substrate move and flex, tackiness agent does not break.At room temperature, tackiness agent component can be storage-stable in at least one month, at least three months or even at least six months.

[0023] It is possible that one or more ingredients used to form the adhesive may include a di-primary amine, such as an amine-terminated butadiene-acrylonitrile copolymer (ATBN) in combination with one or more thiols. One or more ingredients may include a tertiary amine. It is possible that when mixing component A and component B, an initial rapid reaction occurs and creates a thermoplastic material, and a secondary slower reaction creates a thermosetting material. Typically, thiols and epoxies react very quickly, so a large amount of material may not be required to cause sufficient exotherm to produce a rapid reaction. Thus, in combination with the amine-terminated butadiene-acrylonitrile copolymer, the ATBN behaves primarily as a latent curing agent to form a thermosetting material over a long period of time. In this case, the ATBN will have more than two reactive hydrogens. It is possible that the tertiary amine crosslinks the adhesive through homopolymerization of residual epoxy. This reaction can occur at room temperature and is slower than the epoxy / thiol reaction, thereby promoting an optimal thermoplastic phase for assembly.

[0024] The thermoplastic prepolymer included in the component A of the two-component adhesive can be prepared as follows: react a dinucleophile with a stoichiometric excess of epoxy resin to produce a polymer terminated with unreacted epoxy functional groups. A portion of the epoxy can be optionally blended or compounded with a catalyst and heated to high temperatures. The dinucleophile can be optionally blended or compounded with a catalyst and mixed with the epoxy, either in a continuous manner or in incremental form. Once the component A prepolymer is obtained, additional epoxy and silicon dioxide and additional components can be added to form a fully formulated component A.

[0025] The thermoplastic prepolymer that is included in the B component of the adhesive of two components can be prepared as follows: diepoxy and stoichiometric excess dinucleophilic reagent are reacted to produce the polymer with unreacted nucleophilic reagent functional group end-capping.A part of dinucleophilic reagent and optional catalyst can be heated to high temperature.Epoxy can be mixed into then, either in a continuous manner or in increments.In case make the B component prepolymer, extra dinucleophilic reagent and extra components can be added to form the B component of complete preparation.

[0026] The di-functional epoxide can be, for example, an epoxy based on bisphenol A or bisphenol F. For example, the dinucleophile can be a dithiol, a bisphenol, a dicarboxylic acid, a difunctional sulfonamide, or a diamine.

[0027] The optional catalyst discussed herein can be used to promote the epoxy-nucleophilic agent reaction. Once the reaction forming the low molecular weight thermoplastic polymer is basically completed, additional catalysts can be added. When component A and component B are mixed and deposited on the substrate, the reaction between epoxy and the nucleophilic group can begin. The use of a basic catalyst may be desirable, or may be required to control the reaction rate of epoxy and nucleophilic agent in the preparation of thermoplastic prepolymers and the in-situ polymerization step. Once the bonded joint is formed at room temperature or high temperature, the reaction can continue, thereby allowing the full development of adhesive properties. Once the "in-situ" polymerization at the bonded joint is completed, the final polymer can be substantially linear and thermoplastic in nature. The composition can produce a "touch dry" characteristic at room temperature before bonding, even if all epoxy and nucleophilic agent groups have not been completely consumed by the reaction.

[0028] The partially reacted adhesive can be activated by heat exposure, radiation or other external stimulus prior to bringing the two surfaces to be bonded into contact with each other.

[0029] One or more components of the adhesive may include one or more epoxy materials, which may be bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, or aliphatic or alicyclic-based epoxies. Predominantly di-functional epoxies may be selected because monofunctional materials may limit the ability to obtain sufficiently high molecular weights. On the other hand, sufficient tri- or tetrafunctionality may lead to early unfavorable gelation. In addition to either diepoxy or dinucleophilic reagents, one or both of the adhesive components may also include preformed low molecular weight, reactive, substantially linear, reactive prepolymers. The reactive prepolymer may be the reaction product of diepoxy and dinucleophilic reagents, which is prepared using either diepoxy or dinucleophilic reagents in stoichiometric excess. The stoichiometric ratio determines whether the prepolymer is terminated with unreacted epoxy or nucleophilic functional groups. The reactive end group functional groups determine which side of the adhesive the reactive prepolymer is placed.

[0030] The adhesive may also include one or more reinforcing components. Preferably, the reinforcing components include materials that are generally non-reactive with the other components present in the adhesive. It is contemplated that the reinforcing components may act as rheology modifiers.

[0031] The example of reinforcement composition comprises wollastonite, silicon dioxide, diatomite, glass, clay (for example, comprising nanoclay), glass beads or bubbles, glass, carbon fiber or ceramic fiber, nylon, aramid fiber or polyamide fiber etc. The one or more reinforcement compositions can be selected from pyrophyllite, sauconite, saponite, nontronite or montmorillonite. The reinforcement composition can include calcium mineral reinforcement. The reinforcement composition can include glass, glass beads or bubbles, carbon fiber or ceramic fiber, nylon, aramid fiber or polyamide fiber (for example, Kevlar). The adhesive can further include one or more fillers, which include pigment or colorant, calcium carbonate, talc, silicate mineral, vermiculite, mica etc.

[0032] When a reinforcing component is used, the reinforcing component in the adhesive can be less than 0.05% by weight to more than 90% by weight of the adhesive, but more typically about 0.5% by weight to 10% by weight of the adhesive. According to some embodiments, the adhesive can include about 0% by weight to about 30% by weight, more preferably slightly less than 10% by weight reinforcing components.

[0033] The adhesive can be formulated to include an elastomeric component. The elastomeric component can be included in an amount up to about 75% by weight of the adhesive. The elastomeric component can be about at least about 1% by weight of the adhesive, more typically at least about 5% by weight, more typically at least about 10% by weight, and even more typically at least about 15% by weight. The elastomeric component can be solid, liquid, or semisolid at a temperature of 23°C, or some combination thereof.

[0034] The elastomeric component can be a thermosetting liquid or solid elastomer, although it is not required. Exemplary elastomers include, without limitation, natural rubber, styrene-butadiene rubber, polyisoprene, polyisobutylene, diene, isoprene-butadiene copolymer, chloroprene rubber, nitrile rubber (e.g., nitrile such as carboxyl-terminated nitrile), butyl rubber, polysulfide elastomer, acrylic elastomer, acrylonitrile elastomer, silicone rubber, polysiloxane, polyester rubber, diisocyanate-linked condensation elastomer, EPDM (ethylene-propylene diene rubber), chlorosulfonated polyethylene, fluorinated hydrocarbons, etc. Carboxyl-terminated butadiene-acrylonitrile (CTBN) can be particularly useful for forming adhesion.

[0035] The binder may include at least one type of polymeric particles. As used herein, the term "polymeric particles" as with any other component of the present teachings can include one or more types of polymeric particles. For the polymeric particles, it is generally preferred that at least 0.5% by weight of the binder, more typically at least 2% by weight, more typically at least 5% by weight, still more typically at least 7% by weight, and still more typically at least 10% by weight; and for the polymeric particles, it is also preferred that less than 90% by weight of the binder, more typically less than 40% by weight, and still more typically less than 30% by weight, although higher or lower amounts may be used in specific embodiments. One or more types of polymeric particles may include one or any combination of toughening particles, flexible particles, viscosity-modifying particles, or some combination thereof. The polymeric particles may include core-shell materials.

[0036] One or more curing agents may be added to the adhesive. The amount of curing agent in the adhesive can vary widely, depending on the desired structural properties of the adhesive. An exemplary range of curing agent in the adhesive is from about 0.001% by weight to about 7% by weight.

[0037] It is possible that the curing agent assists in curing the adhesive by crosslinking the polymer, epoxy resin, or both. It is also possible for the curing agent to assist in developing or chain extending the adhesive. Useful classes of curing agents are selected from the group consisting of aliphatic or aromatic amines or their respective adducts, amidoamines, polyamides, alicyclic amines, anhydrides, polycarboxylic acid polyesters, isocyanates, phenol-based resins (e.g., phenol or cresol novolac resins, copolymers such as phenol terpene copolymers, polyvinylphenol or bisphenol-A formaldehyde copolymers, bishydroxyphenylalkanes, etc.), or mixtures thereof. Particularly preferred curing agents include modified and unmodified polyamines or polyamides such as triethylenetetramine and / or diethylenetriaminetetraethylenepentamine.

[0038] Adhering low surface energy copolymer to substrate can occur in the absence of any step of priming low surface energy copolymer or substrate. It can occur in the absence of any UV light treatment. It can occur without any initial step of cleaning low surface energy copolymer or cleaning substrate. Adhesive can adhere to low surface energy copolymer and substrate as soon as it contacts. Adhesive can allow low surface energy copolymer to initially contact substrate, and then adjust to ideal coordination without destroying the adhesive properties of adhesive. Described composition and / or adhesive can be applied to low surface energy copolymer, then heat activated subsequently, or even heat activated again before assembly. Adhesion between low surface energy copolymer and substrate can be enough to tear off low surface energy copolymer before adhesive failure on substrate surface.

[0039] The surface having the adhesive component arranged above can be a low surface energy copolymer material.Before any adhesive component is applied, the surface itself can be pre-treated.The surface can be heat-treated to modify the surface of the low surface energy copolymer.The surface can be plasma treated, corona treated, flame treated or processed in a certain way to increase the surface energy of the low surface energy copolymer.The processing can not contain any primer coating.

[0040] Low surface energy copolymers can be injection molded, which typically require the use of a release agent formulation. The release agent formulation can be washed off or not washed off from both the mold and the resulting low surface energy copolymer. Adhesion to the low surface energy copolymer can include penetration of a porous substrate to encapsulate a portion of the porous surface and produce a mechanical bond / interlock. One or more of the ingredients used for adhesion can include an epoxy system with more than two epoxy groups per molecule. One or more of the ingredients can include a reaction initiator with two reactive hydrogens. When these molecules interact, chain extension occurs and causes the generation of polymers. The polymer structure gradually forms adhesive properties with the treated low surface energy copolymer surface and various substrates. The bonding strength of the polymer structure can be partially or entirely the result caused by the polymerization process. Depending on the substrate to which the low surface energy copolymer is adhered, it may be necessary to reach a certain level of reaction process before assembly. A certain amount of reactants and epoxy can be pre-reacted in the adhesive manufacturing process to form a polymer or prepolymer. The polymer can be used as a component in one or more of the adhesive ingredients, as shown in Table 1.

[0041] Table 1

[0042]

[0043]

[0044] Table II below describes non-limiting reaction products of Component A and Component B.

[0045] Table II

[0046]

[0047] As used herein, unless otherwise indicated, the teachings contemplate that any basis of a genus (column) may be excluded from that genus; and / or any basis of a Markush grouping may be excluded from the grouping.

[0048] Unless otherwise stated, any numerical value described herein includes all values ​​from lower values ​​to higher values ​​in increments of one unit, provided that there is an interval of at least 2 units between any lower value and any higher value. As an example, if, for example, the amount of a component, a characteristic or a process variable such as temperature, pressure, time, etc., is specified, for example, to be 1 to 90, preferably 20 to 80, more preferably 30 to 70, then it is intended that intermediate range values ​​(such as, for example, 15 to 85, 22 to 68, 43 to 51, 30 to 32, etc.) are within the teaching of this specification. Similarly, individual intermediate values ​​are also within this teaching. For a value less than 1, a unit is considered to be 0.0001, 0.001, 0.01 or 0.1, as the case may be. These are merely examples of specific intent, and all possible numerical combinations between the lowest and highest values ​​listed will be considered to be clearly stated in a similar manner in this application. It can be seen that the teaching of the amount represented as "parts by weight" in this article also covers the same range represented by weight percentage. Thus, expression of a range expressed as "at least 'x' parts by weight of the resulting composition" also encompasses teaching of a range of the same stated amount of "x" by weight percent of the resulting composition.

[0049] Unless otherwise indicated, all ranges include both endpoints and all numbers between the endpoints. The use of "about" or "approximately" in connection with a range applies to both ends of the range. Thus, "about 20 to 30" is intended to cover "about 20 to about 30", including at least the specified endpoints.

[0050] The disclosures of all articles and references, including patent applications and published references, are incorporated by reference for all purposes. The term "consisting essentially of" to describe a combination shall include the identified elements, ingredients, components, or steps, as well as such other elements, ingredients, components, or steps that do not materially affect the basic and novel characteristics of the combination. The use of the terms "comprising" or "including" to describe a combination of elements, ingredients, components, or steps herein also encompasses embodiments consisting of or consisting essentially of the elements, ingredients, components, or steps.

[0051] Multiple elements, ingredients, components or steps can be provided by a single integrated element, ingredient, component or step. Alternatively, a single integrated element, ingredient, component or step can be divided into separate multiple elements, ingredients, components or steps. The disclosure of "a" or "an" describing an element, ingredient, component or step is not intended to exclude additional elements, ingredients, components or steps.

[0052] It should be understood that the above description is intended to be illustrative rather than restrictive. After reading the above description, many embodiments and many applications other than the provided examples will be apparent to those skilled in the art. Therefore, the scope of the present invention should not be determined with reference to the above description, but rather should be determined with reference to the full scope of the equivalents to which the claims are assigned. The disclosures of all articles and references including patent applications and publications are incorporated by reference for all purposes. The omission of any aspect of the subject matter disclosed herein in the following claims is not a waiver of claims to such subject matter, nor should it be considered that the inventor does not consider such subject matter as part of the disclosed inventive subject matter.

Claims

1. A two-component adhesive composition comprising: Component A, which includes one or more of the following: An epoxy having at least two epoxy groups per molecule; and / or The reaction product of a difunctional epoxy and a thiol functional species; wherein the thiol functional species of component A comprises at least two active hydrogen groups capable of reacting with the epoxy species; Component B, which comprises a difunctional epoxy and thiol functional species reaction product, wherein the thiol functional species contains at least two functional SH groups capable of reacting with the epoxy species; The adhesive composition includes an excess of a tertiary amine for crosslinking the adhesive; The ingredients of Part A and Part B are selected to form an adhesive that is initially a thermoplastic material and becomes a thermoset material over time.

2. The adhesive composition of claim 1, comprising a flexibilizing agent.

3. The adhesive composition of claim 2, wherein the flexibilizing agent is an amine terminated liquid polybutadiene acrylonitrile rubber.

4. The adhesive composition of any one of the preceding claims, comprising a catalyst for producing component A and / or component B.

5. The adhesive composition of claim 1 comprising a particulate modifying material selected from the group consisting of silica, clay, calcium carbonate, mica, other silicates, or combinations thereof.

6. The adhesive composition of claim 1 comprising an odor masking agent.

7. The adhesive composition of claim 6, wherein the odor masking agent also acts as an adhesion promoter.

8. The adhesive composition of claim 1 comprising a crosslinking agent which is a functionalized multifunctional elastomer.

9. A method for adhering a substrate to a low surface energy polymer, comprising: or optionally treating the low surface energy polymer surface physically or chemically to modify the surface energy thereof; Apply the adhesive composition of claim 1.

10. The method of claim 9, wherein the low surface energy polymer surface or substrate is not primed.

11. The method of claim 9 or claim 10, wherein the adhesive is applied to only one of the low surface energy polymer or the substrate.

12. The method of claim 9, wherein the low surface energy polymer is a midsole of a shoe and the substrate is a shoe upper.

13. The method of claim 9, wherein the adhesive is polymerized in situ to form a thermoplastic adhesive.

14. The method of claim 9, comprising heating the adhesive to effect polymerization.

15. The method of claim 9, wherein the low surface energy polymer is an ethylene vinyl acetate-based material.

16. The method of claim 9, wherein the low surface energy polymer is a polyurethane-based material.

17. The method of claim 9, wherein the substrate is a fiber.

18. Use of the adhesive composition of claim 1 for adhering a low surface energy material to a substrate.

19. Use of the adhesive composition of claim 1 for manufacturing shoes.

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