Patent Description:
Coating compositions, including sealants and adhesives, are utilized in a wide variety of applications to treat a variety of substrates or to bond together two or more substrate materials. Epoxy-based adhesive compositions are described, for instance, in <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, and <CIT>. Further epoxy-containing compositions are described, for instance, in <CIT> and <CIT>.

The present invention is directed toward one-component compositions, including adhesive compositions that provide sufficient bond strength and are easy to apply for use in bonding together substrate materials.

Disclosed herein is a composition, comprising: an epoxy-containing component; elastomeric particles in an amount of greater than <NUM>% by weight to <NUM>% by weight based on total weight of the composition, wherein at least <NUM>% by weight of the elastomeric particles comprise a styrene butadiene core based on total weight of the elastomeric particles; and a curing component activatable by an external energy source, the curing component comprising at least one guanidine having a D90 particle size of <NUM> measured by dynamic light scattering.

Also disclosed are coatings, sealants, and adhesives formed from the composition in an at least partially cured state.

Also disclosed is a coated substrate, wherein at least a portion of a surface of the substrate is at least partially coated with a composition comprising an epoxy-containing component, elastomeric particles in an amount of greater than <NUM>% by weight to <NUM>% by weight based on total weight of the composition, wherein at least <NUM>% by weight of the elastomeric particles comprise a styrene butadiene core based on total weight of the elastomeric particles, and a curing component activatable by an external energy source, the curing component comprising at least one guanidine having a D90 particle size of <NUM> measured by dynamic light scattering.

Also disclosed is an article comprising first and second substrates and a composition positioned therebetween and in an at least partially cured state, wherein the composition comprises an epoxy-containing component, elastomeric particles in an amount of greater than <NUM>% by weight to <NUM>% by weight based on total weight of the composition, wherein at least <NUM>% by weight of the elastomeric particles comprise a styrene butadiene core based on total weight of the elastomeric particles, and a curing component activatable by an external energy source, the curing component comprising at least one guanidine having a D90 particle size of <NUM> measured by dynamic light scattering.

Also disclosed is a method for forming a coating on a substrate surface comprising applying a composition to at least a portion of the substrate surface, the composition comprising an epoxy-containing component, elastomeric particles in an amount of greater than <NUM>% by weight to <NUM>% by weight based on total weight of the composition, wherein at least <NUM>% by weight of the elastomeric particles comprise a styrene butadiene core based on total weight of the elastomeric particles, and a curing component activatable by an external energy source, the curing component comprising at least one guanidine having a D90 particle size of <NUM> measured by dynamic light scattering.

Also disclosed is a method for forming a bond between two substrates comprising: applying a composition comprising an epoxy-containing component, elastomeric particles in an amount of greater than <NUM>% by weight to <NUM>% by weight based on total weight of the composition, wherein at least <NUM>% by weight of the elastomeric particles comprise a styrene butadiene core based on total weight of the elastomeric particles, and a curing component activatable by an external energy source, the curing component comprising at least one guanidine having a D90 particle size of <NUM> measured by dynamic light scattering, such that the composition is located between the first and the second substrate; and applying an external energy source to cure the composition.

Also disclosed are substrates formed by the methods of the present invention.

<FIG> is a graph illustrating shear stress versus shear strain curves for (comparative) compositions I through VIII (Example <NUM>) collected according to ISO <NUM>-<NUM>.

For purposes of the following detailed description, it is to be understood that the invention may assume various alternative variations and step sequences, except where expressly specified to the contrary. Moreover, other than in any operating examples, or where otherwise indicated, all numbers such as those expressing values, amounts, percentages, ranges, subranges and fractions may be read as if prefaced by the word "about," even if the term does not expressly appear. Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Where a closed or open-ended numerical range is described herein, all numbers, values, amounts, percentages, subranges and fractions within or encompassed by the numerical range are to be considered as being specifically included in and belonging to the original disclosure of this application as if these numbers, values, amounts, percentages, subranges and fractions had been explicitly written out in their entirety.

As used herein, unless indicated otherwise, a plural term can encompass its singular counterpart and vice versa, unless indicated otherwise. For example, although reference is made herein to "an" epoxy and "a" curing agent, a combination (i.e., a plurality) of these components can be used.

In addition, in this application, the use of "or" means "and/or" unless specifically stated otherwise, even though "and/or" may be explicitly used in certain instances.

As used herein, "including," "containing" and like terms are understood in the context of this application to be synonymous with "comprising" and are therefore open-ended and do not exclude the presence of additional undescribed or unrecited elements, materials, ingredients or method steps. As used herein, "consisting of" is understood in the context of this application to exclude the presence of any unspecified element, ingredient or method step. As used herein, "consisting essentially of" is understood in the context of this application to include the specified elements, materials, ingredients or method steps "and those that do not materially affect the basic and novel characteristic(s)" of what is being described.

As used herein, the terms "on," "onto," "applied on," "applied onto," "formed on," "deposited on," "deposited onto," mean formed, overlaid, deposited, or provided on but not necessarily in contact with the surface. For example, a coating composition "applied onto" a substrate does not preclude the presence of one or more other intervening coating layers of the same or different composition located between the coating composition and the substrate.

As used herein, a "coating composition" refers to a composition, e.g., a solution, mixture, or a dispersion, that, in an at least partially dried or cured state, is capable of producing a film, layer, or the like on at least a portion of a substrate surface.

As used herein, a "sealant composition" refers to a coating composition, e.g., a solution, mixture, or a dispersion, that, in an at least partially dried or cured state, has the ability to resist atmospheric conditions and particulate matter, such as moisture and temperature and at least partially block the transmission of materials, such as particulates, water, fuel, or other liquids and gasses.

As used herein, the term "structural adhesive" means an adhesive producing a load-bearing joint having both a lap shear strength of greater than <NUM> MPa, measured according to ASTM D1002-<NUM> using <NUM>-T3 aluminum substrate of <NUM> thickness, as measured by an INSTRON <NUM> machine in tensile mode with a pull rate of <NUM> per minute, and a lap shear displacement at failure of at least <NUM>% of the overlap length. As defined herein, a "<NUM>" or "one-component" coating composition, is a composition in which all of the ingredients may be premixed and stored and wherein the reactive components do not readily react at ambient or slightly thermal conditions, but instead only react upon activation by an external energy source. In the absence of activation from the external energy source, the composition will remain largely unreacted (maintaining sufficient workability in the uncured state and greater than <NUM>% of the initial lap shear strength of the composition in the cured state after storage at <NUM> for <NUM> months). External energy sources that may be used to promote the curing reaction (i.e., the crosslinking of the epoxy component and the curing agent) include, for example, radiation (i.e., actinic radiation) and/or heat.

As further defined herein, ambient conditions generally refer to room temperature and humidity conditions or temperature and humidity conditions that are typically found in the area in which the adhesive is being applied to a substrate, e.g., at <NUM> to <NUM> and <NUM>% to <NUM>% relative humidity, while slightly thermal conditions are temperatures that are slightly above ambient temperature but are generally below the curing temperature for the coating composition (i.e. in other words, at temperatures and humidity conditions below which the reactive components will readily react and cure, e.g., > <NUM> and less than <NUM> at <NUM>% to <NUM>% relative humidity).

As used herein, "Mw" refers to the weight average molecular weight and means the theoretical value as determined by Gel Permeation Chromatography using Waters <NUM> separation module with a Waters <NUM> differential refractometer (RI detector) and polystyrene standards. Tetrahydrofuran (THF) used as the eluent at a flow rate of <NUM> min-<NUM>, and two PL Gel Mixed C columns used for separation.

As used herein, the term "catalyst" means a substance that increases the rate or decreases the activation energy of a chemical reaction without itself undergoing any permanent chemical change.

As used herein, the term "latent curing agent" or "blocked curing agent" or "encapsulated curing agent" means a molecule or a compound that is activated by an external energy source prior to reacting or having a catalytic effect. For example, the latent curing agent may be in the form of a solid at room temperature and have no catalytic effect until it is heated and melts, or the latent curing agent may be reversibly reacted with a second compound that prevents any catalytic effect until the reversible reaction is reversed by the application of heat and the second compound is removed, freeing the curing agent to react or catalyze reactions.

As used herein, the term "second curing agent" means a curing agent or catalyst in the coating composition in addition to the curing component that comprises the at least one guanidine described herein.

As used herein, the term "cure", "cured" or similar terms, as used in connection with the composition described herein, means that at least a portion of the components that form the composition are crosslinked to form a coating, film, layer, or bond. Additionally, curing of the composition refers to subjecting said composition to curing conditions (e.g., elevated temperature) leading to the reaction of the reactive functional groups of the components of the composition, and resulting in the crosslinking of the components of the composition and formation of an at least partially cured coating. As used herein, the term "at least partially cured" with respect to a coating refers to a coating formed by subjecting the composition to curing conditions such that a chemical reaction of at least a portion of the reactive groups of the components of the composition occurs to form a coating, film, layer, or bond. A coating composition may be considered to be "at least partially cured" if it has a lap shear strength of at least <NUM> MPa (measured according to ASTM D1002-<NUM>). The coating composition may also be subjected to curing conditions such that a substantially complete cure is attained and wherein further curing results in no significant further improvement in the coating properties such as, for example, increased lap shear performance.

As used herein, unless indicated otherwise, the term "substantially free" means that a particular material is not purposefully added to a mixture or composition, respectively, and is only present as an impurity in a trace amount of less than <NUM>% by weight based on a total weight of the mixture or composition, respectively. As used herein, unless indicated otherwise, the term "essentially free" means that a particular material is only present in an amount of less than <NUM>% by weight based on a total weight of the mixture or composition, respectively. As used herein, unless indicated otherwise, the term "completely free" means that a mixture or composition, respectively, does not comprise a particular material, i.e., the mixture or composition comprises <NUM>% by weight of such material.

The present invention is directed to a composition comprising, or consisting essentially of, or consisting of, an epoxy-containing component, elastomeric particles in an amount of greater than <NUM>% by weight to <NUM>% by weight based on total weight of the composition, wherein at least <NUM>% by weight of the elastomeric particles comprise a styrene butadiene core based on total weight of the elastomeric particles; and a curing component activatable by an external energy source, the curing component comprising at least one guanidine having a D90 particle size of <NUM> measured by dynamic light scattering. As used herein, the term "D90" means the point in the size distribution in which <NUM> percent or more of the total volume of material in the sample is contained. For example, a D90 of <NUM> means that <NUM>% of the particles of the sample have a size of <NUM> or smaller. The composition may be a coating composition, such as a sealant composition or an adhesive composition which, in an at least partially cured state, may form a coating, such as an adhesive or a sealant.

Also disclosed is a method for forming a coating on a substrate surface comprising, or consisting essentially of, or consisting of, applying a composition to at least a portion of the substrate surface. The composition may comprise, or consist essentially of, or consist of, an epoxy-containing component, elastomeric particles in an amount of greater than <NUM>% by weight to <NUM>% by weight based on total weight of the composition, wherein at least <NUM>% by weight of the elastomeric particles comprise a styrene butadiene core based on total weight of the elastomeric particles, and a curing component activatable by an external energy source, the curing component comprising at least one guanidine having a D90 particle size of <NUM> measured by dynamic light scattering.

Also disclosed is a method for forming a bond between two substrates comprising, or consisting essentially of, or consisting of, applying a composition to at least a portion of a surface of the first substrate, such that the composition is located between the first and the second substrate; and applying an external energy source to cure the composition. The composition may comprise, or consist essentially of, or consist of, an epoxy-containing component, elastomeric particles in an amount of greater than <NUM>% by weight to <NUM>% by weight based on total weight of the composition, wherein at least <NUM>% by weight of the elastomeric particles comprise a styrene butadiene core based on total weight of the elastomeric particles, and a curing component activatable by an external energy source, the curing component comprising at least one guanidine having a D90 particle size of <NUM> measured by dynamic light scattering.

Also disclosed are substrates and articles comprising, or consisting essentially of, or consisting of, coatings formed from the compositions of the present invention. For example, also disclosed is a coated substrate, wherein at least a portion of a surface of the substrate is at least partially coated with a composition comprising, or consisting essentially of, or consisting of, an epoxy-containing component, elastomeric particles in an amount of greater than <NUM>% by weight to <NUM>% by weight based on total weight of the composition, wherein at least <NUM>% by weight of the elastomeric particles comprise a styrene butadiene core based on total weight of the elastomeric particles, and a curing component activatable by an external energy source, the curing component comprising at least one guanidine having a D90 particle size of <NUM> measured by dynamic light scattering. Also disclosed is an article comprising, or consisting essentially of, or consisting of, first and second substrates and a composition positioned therebetween and in an at least partially cured state, wherein the composition comprises, or consists essentially of, or consists of, an epoxy-containing component, elastomeric particles in an amount of greater than <NUM>% by weight to <NUM>% by weight based on total weight of the composition, wherein at least <NUM>% by weight of the elastomeric particles comprise a styrene butadiene core based on total weight of the elastomeric particles, and a curing component activatable by an external energy source, the curing component comprising at least one guanidine having a D90 particle size of <NUM> measured by dynamic light scattering.

The coating composition may comprise an epoxy compound. Suitable epoxy compounds that may be used include monoepoxides, polyepoxides, or combinations thereof.

Suitable monoepoxides that may be used include monoglycidyl ethers of alcohols and phenols, such as phenyl glycidyl ether, n-butyl glycidyl ether, cresyl glycidyl ether, isopropyl glycidyl ether, glycidyl versatate, for example, CARDURA E available from Shell Chemical Co. , and glycidyl esters of monocarboxylic acids such as glycidyl neodecanoate, and mixtures of any of the foregoing.

Useful epoxy-containing components that can be used include polyepoxides (having an epoxy functionality greater than <NUM>), epoxy adducts, or combinations thereof. Suitable polyepoxides include polyglycidyl ethers of Bisphenol A, such as Epon® <NUM> and <NUM> epoxy resins, and Bisphenol F polyepoxides, such as Epon® <NUM>, which are commercially available from Hexion Specialty Chemicals, Inc. Other useful polyepoxides include polyglycidyl ethers of polyhydric alcohols, polyglycidyl esters of polycarboxylic acids, polyepoxides that are derived from the epoxidation of an olefinically unsaturated alicyclic compound, polyepoxides containing oxyalkylene groups in the epoxy molecule, and epoxy novolac resins. Still other non-limiting epoxy compounds include epoxidized Bisphenol A novolacs, epoxidized phenolic novolacs, epoxidized cresylic novolac, isosorbide diglycidyl ether, triglycidyl p-aminophenol, and triglycidyl p-aminophenol bismaleimide, triglycidyl isocyanurate, tetraglycidyl <NUM>,<NUM>'-diaminodiphenylmethane, and tetraglycidyl <NUM>,<NUM>'-diaminodiphenylsulphone. The epoxy-containing compound may also comprise an epoxy-dimer acid adduct. The epoxy-dimer acid adduct may be formed as the reaction product of reactants comprising a diepoxide compound (such as a polyglycidyl ether of Bisphenol A) and a dimer acid (such as a C36 dimer acid). The epoxy-containing compound may also comprise a carboxyl-terminated butadiene-acrylonitrile copolymer modified epoxy-containing compound. The epoxy-containing compound may also comprise epoxidized castor oil. The epoxy-containing compound may also comprise an epoxy-containing acrylic, such as glycidyl methacrylate.

The epoxy-containing compound may comprise an epoxy-adduct. The composition may comprise one or more epoxy-adducts. As used herein, the term "epoxy-adduct" refers to a reaction product comprising the residue of an epoxy compound and at least one other compound that does not include an epoxide functional group. For example, the epoxy-adduct may comprise the reaction product of reactants comprising: (<NUM>) an epoxy compound, a polyol, and an anhydride; (<NUM>) an epoxy compound, a polyol, and a diacid; or (<NUM>) an epoxy compound, a polyol, an anhydride, and a diacid.

The epoxy compound used to form the epoxy-adduct may comprise any of the epoxy-containing compounds listed above that may be included in the composition.

The polyol used to form the epoxy-adduct may include diols, triols, tetraols and higher functional polyols. Combinations of such polyols may also be used. The polyols may be based on a polyether chain derived from ethylene glycol, propylene glycol, butylene glycol, hexylene glycol and the like as well as mixtures thereof. The polyol may also be based on a polyester chain derived from ring opening polymerization of caprolactone (referred to as polycaprolactone-based polyols hereinafter). Suitable polyols may also include polyether polyols, polyurethane polyols, polyurea polyols, acrylic polyols, polyester polyols, polybutadiene polyols, hydrogenated polybutadiene polyols, polycarbonate polyols, polysiloxane polyols, and combinations thereof. Polyamines corresponding to polyols may also be used, and in this case, amides instead of carboxylic esters will be formed with the diacids and anhydrides.

The polyol may comprise a polycaprolactone-based polyol. The polycaprolactone-based polyols may comprise diols, triols or tetraols terminated with primary hydroxyl groups. Commercially available polycaprolactone-based polyols include those sold under the trade name Capa™ from Perstorp Group, such as, for example, Capa <NUM>, Capa 2077A, Capa <NUM>, Capa <NUM>, Capa <NUM>, Capa <NUM>, Capa <NUM> and Capa <NUM>.

The polyol may comprise a polytetrahydrofuran-based polyol. The polytetrahydrofuran-based polyols may comprise diols, triols or tetraols terminated with primary hydroxyl groups. Commercially available polytetrahydrofuran-based polyols include those sold under the trade name Terathane®, such as Terathane® PTMEG <NUM> and Terathane® PTMEG <NUM> which are blends of linear diols in which the hydroxyl groups are separated by repeating tetramethylene ether groups, available from Invista. In addition, polyols based on dimer diols sold under the trade names Pripol®, Solvermol™ and Empol®, available from Cognis Corporation, or bio-based polyols, such as the tetrafunctional polyol Agrol <NUM>, available from BioBased Technologies, may also be utilized.

The anhydride that may be used to form the epoxy-adduct may comprise any suitable acid anhydride known in the art. For example, the anhydride may comprise hexahydrophthalic anhydride and its derivatives (e.g., methyl hexahydrophthalic anhydride); phthalic anhydride and its derivatives (e.g., methyl phthalic anhydride); maleic anhydride; succinic anhydride; trimelletic anhydride; pyromelletic dianhydride (PMDA); <NUM>,<NUM>',<NUM>,<NUM>'-oxydiphthalic dianhydride (ODPA); <NUM>,<NUM>',<NUM>,<NUM>'-benzopherone tetracarboxylic dianhydride (BTDA); and <NUM>,<NUM>'-diphthalic (hexafluoroisopropylidene) anhydride (6FDA).

The diacid used to form the epoxy-adduct may comprise any suitable diacid known in the art. For example, the diacids may comprise phthalic acid and its derivates (e.g., methyl phthalic acid), hexahydrophthalic acid and its derivatives (e.g., methyl hexahydrophthalic acid), maleic acid, succinic acid, adipic acid, and the like.

The epoxy-adduct may comprise a diol, a monoanhydride or a diacid, and a diepoxy compound, wherein the mole ratio of diol, monoanhydride (or diacid), and diepoxy compounds in the epoxy-adduct may vary from <NUM>:<NUM>:<NUM> to <NUM>:<NUM>:<NUM>.

The epoxy-adduct may comprise a triol, a monoanhydride or a diacid, and a diepoxy compound, wherein the mole ratio of triol, monoanhydride (or diacid), and diepoxy compounds in the epoxy-adduct may vary from <NUM>:<NUM>:<NUM> to <NUM>:<NUM>:<NUM>.

The epoxy-adduct may comprise a tetraol, a monoanhydride or a diacid, and a diepoxy compound, wherein the mole ratio of tetraol, monoanhydride (or diacid), and diepoxy compounds in the epoxy-adduct may vary from <NUM>:<NUM>:<NUM> to <NUM>:<NUM>:<NUM>.

Other suitable epoxy-containing components include epoxy-adducts such as epoxy polyesters formed as the reaction product of reactants comprising an epoxy-containing compound, a polyol and an anhydride, as described in <CIT>, col. <NUM>, line <NUM> through col. <NUM>, line <NUM>.

The epoxy-containing component may have an average epoxide functionality of greater than <NUM>, such as at least <NUM>, and may have an average epoxide functionality of less than <NUM>, such as no more than <NUM>. The epoxy-containing component may have an average epoxide functionality of greater than <NUM> to less than <NUM>, such as <NUM> to <NUM>. As used herein, the term "average epoxide functionality" means the molar ratio of epoxide functional groups to epoxide-containing molecules in the composition.

According to the present invention, the epoxy-containing component may be present in the composition in an amount of at least <NUM>% by weight based on the total composition weight, such as at least <NUM>%, and in some cases may be present in the coating composition in an amount of no more than <NUM>% by weight based on the total composition weight, such as no more than <NUM>%. According to the present invention, the epoxy-containing component may be present in the coating composition in an amount of from <NUM>% to <NUM>% by weight based on the total composition weight, such as from <NUM>% to <NUM>%.

According to the present invention, the epoxy equivalent weight of the epoxy-containing component of the coating composition may be at least <NUM>/eq, such as at least <NUM>/eq, such as at least <NUM>/eq, such as at least <NUM>/eq, such as at least <NUM>/eq, such as at least <NUM>,<NUM>/eq, and in some cases may be no more than <NUM>,<NUM>/eq, such as no more than <NUM>,<NUM>/eq, such as no more than <NUM>/eq, such as no more than <NUM>/eq. According to the present invention, the epoxy equivalent weight of the epoxy-containing component of the coating composition can range from <NUM>/eq to <NUM>,<NUM>/eq, such as from <NUM>/eq to <NUM>,<NUM>/eq, such as from <NUM>/eq to <NUM>/eq. As used herein, the "epoxy equivalent weight" is determined by dividing the molecular weight of the epoxy-containing component by the number of epoxy groups present in the epoxy-containing component.

According to the present invention, the molecular weight (Mw) of the epoxy-containing component of the coating composition may be at least <NUM>/mol, such as at least <NUM>/mol, such as at least <NUM>/mol, such as at least <NUM>/mol, such as at least <NUM>/mol, such as at least <NUM>,<NUM>/mol, and in some cases no more than <NUM>,<NUM>/mol, such as no more than <NUM>,<NUM>/mol, such as no more than <NUM>,<NUM>/mol, such as no more than <NUM>/mol, such as no more than <NUM>/mol. According to the present invention, the molecular weight of the epoxy-containing component of the coating composition can range from <NUM>/mol to <NUM>,<NUM>/mol, such as from <NUM>/mol to <NUM>,<NUM>/mol, such as from <NUM>/mol to <NUM>,<NUM>/mol, such as from <NUM>/mol to <NUM>,<NUM>/mol.

The coating composition according to the present invention further comprises elastomeric particles. As used herein, "elastomeric particles" refers to particles comprised of one or more materials having at least one glass transition temperature (Tg) of greater than - <NUM> and less than <NUM>, calculated, for example, using the Fox Equation. The elastomeric particles may be phase-separated from the epoxy-containing component. As used herein, the term "phase-separated" means forming a discrete domain within a matrix of the epoxy-containing component.

The elastomeric particles may have a core/shell structure, wherein at least <NUM>% by weight of the elastomeric particles comprise a styrene butadiene core based on total weight of the elastomeric particles. Suitable core-shell elastomeric particles may be comprised of an acrylic shell and an elastomeric core. The core may comprise natural or synthetic rubbers, polybutadiene, styrene-butadiene, polyisoprene, chloroprene, acrylonitrile butadiene, butyl rubber, polysiloxane, polysulfide, ethylene-vinyl acetate, fluoroelastomer, polyolefin, or combinations thereof. At least <NUM>% by weight of the elastomeric particles comprise a styrene butadiene core based on total weight of the elastomeric particles.

According to the present invention, the average particle size of the elastomeric particles may be at least <NUM>, as measured by transmission electron microscopy (TEM), such as at least <NUM>, such as at least <NUM>, such as at least <NUM>, and may be no more than <NUM>, such as no more than <NUM>, such as no more than <NUM>, such as no more than <NUM>. According to the present invention, the average particle size of the elastomeric particles may be <NUM> to <NUM> as measured by TEM, such as <NUM>, to <NUM>, such as <NUM> to <NUM>, such as <NUM> to <NUM>. Suitable methods of measuring particle sizes by TEM include suspending elastomeric particles in a solvent selected such that the particles do not swell, and then drop casting the suspension onto a TEM grid which is allowed to dry under ambient conditions. For example, epoxy resin containing core-shell rubber elastomeric particles from Kaneka Texas Corporation can be diluted in butyl acetate for drop casting. Particle size measurements may be obtained from images acquired using a Tecnai T20 TEM operating at 200kV and analyzed using ImageJ software, or an equivalent instrument and software.

According to the present invention, the elastomeric particles may optionally be included in an epoxy carrier resin for introduction into the coating composition. Suitable finely dispersed core-shell elastomeric particles in an average particle size ranging from <NUM> to <NUM> may be master-batched in epoxy resin such as aromatic epoxides, phenolic novolac epoxy resin, bisphenol A and/or bisphenol F diepoxide, and/or aliphatic epoxides, which include cyclo-aliphatic epoxides, at concentrations ranging from <NUM>% to <NUM>% core-shell elastomeric particles by weight based on the total weight of the elastomeric dispersion, such as from <NUM>% to <NUM>%, such as from <NUM>% to <NUM>%. Suitable epoxy resins may also include a mixture of epoxy resins. When utilized, the epoxy carrier resin may be an epoxy-containing component of the present invention such that the weight of the epoxy-containing component present in the coating composition includes the weight of the epoxy carrier resin.

Exemplary non-limiting commercial core-shell elastomeric particle products using poly(butadiene) rubber particles that may be utilized in the coating composition of the present invention include core-shell poly(butadiene) rubber powder (commercially available as PARALOID™ EXL 2650A from Dow Chemical), a core-shell poly(butadiene) rubber dispersion (<NUM>% core-shell rubber by weight) in bisphenol F diglycidyl ether (commercially available as Kane Ace MX <NUM>), a core-shell poly(butadiene) rubber dispersion (<NUM>% core-shell rubber by weight) in Epon® <NUM> (commercially available as Kane Ace MX <NUM>), a core-shell poly(butadiene) rubber dispersion (<NUM>% core-shell rubber by weight) in Epiclon® EXA-835LV (commercially available as Kane Ace MX <NUM>), a core-shell poly(butadiene) rubber dispersion (<NUM>% core-shell rubber by weight) in bisphenol A diglycidyl ether (commercially available as Kane Ace MX <NUM>), and a core-shell poly(butadiene) rubber dispersion (<NUM>% core-shell rubber by weight) in Epon® <NUM> (commercially available as Kane Ace MX <NUM>), each available from Kaneka Texas Corporation.

Exemplary non-limiting commercial core-shell elastomeric particle products using styrene-butadiene rubber particles that may be utilized in the coating composition include a core-shell styrene-butadiene rubber powder (commercially available as CLEARSTRENGTH® XT100 from Arkema), core-shell styrene-butadiene rubber powder (commercially available as PARALOID™ EXL 2650J), a core-shell styrene-butadiene rubber dispersion (<NUM>% core-shell rubber by weight) in bisphenol A diglycidyl ether (commercially available as Fortegra™ <NUM> from Olin™), core-shell styrene-butadiene rubber dispersion (<NUM>% rubber by weight) in low viscosity bisphenol A diglycidyl ether (commercially available as Kane Ace MX <NUM>), a core-shell styrene-butadiene rubber dispersion (<NUM>% core-shell rubber by weight) in bisphenol A diglycidyl ether (commercially available as Kane Ace MX <NUM>), a core-shell styrene-butadiene rubber dispersion (<NUM>% core-shell rubber by weight) in bisphenol F diglycidyl ether (commercially available as Kane Ace MX <NUM>), a core-shell styrene-butadiene rubber dispersion (<NUM>% core-shell rubber by weight) in D. ™-<NUM> phenolic novolac epoxy (commercially available as Kane Ace MX <NUM>), a core-shell styrene-butadiene rubber dispersion (<NUM>% core-shell rubber by weight) in Araldite® MY-<NUM> multi-functional epoxy (commercially available as Kane Ace MX <NUM>), a core-shell styrene-butadiene rubber dispersion (<NUM>% core-shell rubber by weight) in MY-<NUM> multi-functional epoxy (commercially available as Kane Ace MX <NUM>), a core-shell styrene-butadiene rubber dispersion (<NUM>% core-shell rubber by weight) in Syna Epoxy <NUM> Cyclo-aliphatic Epoxy from Synasia (commercially available as Kane Ace MX <NUM>), and a core-shell styrene-butadiene rubber dispersion (<NUM>% core-shell rubber by weight) in polypropylene glycol (MW <NUM>) (commercially available as Kane Ace MX <NUM>), each available from Kaneka Texas Corporation.

Exemplary non-limiting commercial core-shell elastomeric particle products using polysiloxane rubber particles that may be utilized in the coating composition of the present invention include a core-shell polysiloxane rubber powder (commercially available as GENIOPERL® P52 from Wacker), a core-shell polysiloxane rubber dispersion (<NUM>% core-shell rubber by weight) in bisphenol A diglycidyl ether (commercially available as ALBIDUR™ EP2240A from Evonick), a core-shell polysiloxane rubber dispersion (<NUM>% core-shell rubber by weight) in jER™<NUM> (commercially available as Kane Ace MX <NUM>), a core-shell polysiloxane rubber dispersion (<NUM>% core-shell rubber by weight) in Epon® <NUM> (commercially available as Kane Ace MX <NUM>) each available from Kaneka Texas Corporation.

The elastomeric particles may be present in the composition in an amount of greater than <NUM>% by weight based on the total composition weight, such as at least <NUM>%, and in some cases may be present in the composition in an amount of no more than <NUM>% by weight based on the total composition weight, such as no more than <NUM>%, such as no more than <NUM>%. According to the present invention, the elastomeric particles may be present in the composition in an amount of from greater than <NUM>% to <NUM>% by weight based on the total composition weight, such as greater than <NUM>% to <NUM>%, such as from <NUM>% to <NUM>%.

According to the present invention, at least <NUM>% by weight of the elastomeric particles comprise a styrene butadiene core based on total weight of the elastomeric particles in the coating composition. For example, elastomeric particles comprising a styrene butadiene core may be present in the coating composition in an amount of at least <NUM>% by weight based on total weight of the elastomeric particles, such as at least <NUM>% by weight, such as at least <NUM>% by weight, and may be present in an amount of <NUM>% by weight based on total weight of elastomeric particles in the coating composition, such as no more <NUM>% by weight, such as no more than <NUM>% by weight. Elastomeric particles comprising a styrene butadiene core may be present in the coating composition in an amount of <NUM>% by weight to <NUM>% by weight based on total weight of the elastomeric particles in the coating composition, such as <NUM>% by weight to <NUM>% by weight, such as <NUM>% by weight to <NUM>% by weight.

According to the present invention, at least <NUM>% by weight of the elastomeric particles have an average particle size (based on TEM as described herein) of no more than <NUM> based on total weight of the elastomeric particles in the coating composition, such as <NUM> to <NUM>. For example, elastomeric particles having an average particle size (based on TEM as described herein) of no more than <NUM>, such as <NUM> to <NUM>, may be present in the coating composition in an amount of at least <NUM>% by weight based on total weight of the elastomeric particles, such as at least <NUM>% by weight, such as at least <NUM>% by weight, and may be present in an amount of <NUM>% by weight based on total weight of elastomeric particles in the coating composition, such as no more <NUM>% by weight, such as no more than <NUM>% by weight. Elastomeric particles having an average particle size of <NUM> (based on TEM as described herein), such as <NUM> to <NUM>, may be present in the coating composition in an amount of <NUM>% by weight to <NUM>% by weight based on total weight of the elastomeric particles in the coating composition, such as <NUM>% by weight to <NUM>% by weight, such as <NUM>% by weight to <NUM>% by weight.

According to the present invention, no more than <NUM>% by weight of the elastomeric particles comprise a polybutadiene core based on total weight of the elastomeric particles in the coating composition. For example, if elastomeric particles containing a polybutadiene core are present at all, they may be present in an amount of at least <NUM>% by weight based on total weight of the elastomeric particles, such as at least <NUM>%, and may be present in an amount of no more than <NUM>% by weight based on total weight of the elastomeric particles, such as no more than <NUM>% by weight, such as no more than <NUM>% by weight. Elastomeric particles containing a polybutadiene core may be present in the coating composition of the present invention in an amount of <NUM>% by weight to <NUM>% by weight based on total weight of the elastomeric particles, such as <NUM>% by weight to <NUM>%, such as <NUM>% by weight to <NUM>% by weight.

According to the present invention, no more than <NUM>% by weight of the elastomeric particles comprise a polysiloxane core based on total weight of the elastomeric particles in the coating composition. For example, if elastomeric particles containing a polysiloxane core are present at all, they may be present in an amount of at least <NUM>% by weight based on total weight of the elastomeric particles, such as at least <NUM>%, and may be present in an amount of no more than <NUM>% by weight based on total weight of the elastomeric particles, such as no more than <NUM>% by weight, such as no more than <NUM>% by weight. Elastomeric particles comprising a polysiloxane core may be present in the coating composition of the present invention in an amount of <NUM>% by weight to <NUM>% by weight based on total weight of the elastomeric particles, such as <NUM>% by weight to <NUM>%, such as <NUM>% by weight to <NUM>% by weight.

The composition of the present invention further comprises a curing component activatable by an external energy source, the curing component comprising, or consisting essentially of, or consisting of, a guanidine. It will be understood that "guanidine," as used herein, refers to guanidine and derivatives thereof. For example, the curing component that may be used includes guanidines, substituted guanidines, substituted ureas, melamine resins, guanamine derivatives, heat-activated cyclic tertiary amines, aromatic amines and/or mixtures thereof. Examples of substituted guanidines are methylguanidine, dimethylguanidine, trimethylguanidine, tetramethylguanidine, methylisobiguanidine, dimethylisobiguanidine, tetramethylisobiguanidine, hexamethylisobiguanidine, heptamethylisobiguanidine and, more especially, cyanoguanidine (dicyandiamide, e.g. Dyhard® available from AlzChem). Representatives of suitable guanamine derivatives which may be mentioned are alkylated benzoguanamine resins, benzoguanamine resins or methoxymethylethoxymethylbenzoguanamine.

For example, the guanidine may comprise a compound, moiety, and/or residue having the following general structure:
<CHM>
wherein each of R1, R2, R3, R4, and R5 (i.e., substituents of structure (I)) comprise hydrogen, (cyclo)alkyl, aryl, aromatic, organometallic, a polymeric structure, or together can form a cycloalkyl, aryl, or an aromatic structure, and wherein R1, R2, R3, R4, and R5 may be the same or different. As used herein, "(cyclo)alkyl" refers to both alkyl and cycloalkyl. When any of the R groups "together can form a (cyclo)alkyl, aryl, and/or aromatic group", it is meant that any two adjacent R groups are connected to form a cyclic moiety, such as the rings in structures (II) - (V) below.

It will be appreciated that the double bond between the carbon atom and the nitrogen atom that is depicted in structure (I) may be located between the carbon atom and another nitrogen atom of structure (I). Accordingly, the various substituents of structure (I) may be attached to different nitrogen atoms depending on where the double bond is located within the structure.

The guanidine may comprise a cyclic guanidine such as a guanidine of structure (I) wherein two or more R groups of structure (I) together form one or more rings. In other words, the cyclic guanidine may comprise ≥<NUM> ring(s). For example, the cyclic guanidine may either be a monocyclic guanidine (<NUM> ring) such as depicted in structures (II) and (III) below, or the cyclic guanidine may be bicyclic or polycyclic guanidine (≥<NUM> rings) such as depicted in structures (IV) and (V) below. <CHM>
<CHM>
<CHM>
<CHM>.

Each substituent of structures (II) and/or (III), R1-R7, may comprise hydrogen, (cyclo)alkyl, aryl, aromatic, organometallic, a polymeric structure, or together can form a cycloalkyl, aryl, or an aromatic structure, and wherein R1-R7 may be the same or different. Similarly, each substituent of structures (IV) and (V), R1-R9, may be hydrogen, alkyl, aryl, aromatic, organometallic, a polymeric structure, or together can form a cycloalkyl, aryl, or an aromatic structure, and wherein R1-R9 may be the same or different. Moreover, in some examples of structures (II) and/or (III), certain combinations of R1-R7 may be part of the same ring structure. For example, R1 and R7 of structure (II) may form part of a single ring structure. Moreover, it will be understood that any combination of substituents (R1-R7 of structures (II) and/or (III) as well as R1-R9 of structures (IV) and/or (V)) may be chosen so long as the substituents do not substantially interfere with the catalytic activity of the cyclic guanidine.

Each ring in the cyclic guanidine may be comprised of ≥<NUM> members. For example, the cyclic guanidine may comprise a <NUM>-member ring, a <NUM>-member ring, and/or a <NUM>-member ring. As used herein, the term "member" refers to an atom located in a ring structure. Accordingly, a <NUM>-member ring will have <NUM> atoms in the ring structure ("n" and/or "m"=<NUM> in structures (II)-(V)), a <NUM>-member ring will have <NUM> atoms in the ring structure ("n" and/or "m"=<NUM> in structures (II)-(V)), and a <NUM>-member ring will have <NUM> atoms in the ring structure ("n" and/or "m"=<NUM> in structures (II)-(V)). It will be appreciated that if the cyclic guanidine is comprised of ≥<NUM> rings (e.g., structures (IV) and (V)), the number of members in each ring of the cyclic guanidine can either be the same or different. For example, one ring may be a <NUM>-member ring while the other ring may be a <NUM>-member ring. If the cyclic guanidine is comprised of ≥<NUM> rings, then in addition to the combinations cited in the preceding sentence, the number of members in a first ring of the cyclic guanidine may be different from the number of members in any other ring of the cyclic guanidine.

It will also be understood that the nitrogen atoms of structures (II)-(V) may further have additional atoms attached thereto. Moreover, the cyclic guanidine may either be substituted or unsubstituted. For example, as used herein in conjunction with the cyclic guanidine, the term "substituted" refers to a cyclic guanidine wherein R5, R6, and/or R7 of structures (II) and/or (III) and/or R9 of structures (IV) and/or (V) is not hydrogen. As used herein in conjunction with the cyclic guanidine, the term "unsubstituted" refers to a cyclic guanidine wherein R1-R7 of structures (II) and/or (III) and/or R1-R9 of structures (IV) and/or (V) are hydrogen.

The cyclic guanidine may comprise a bicyclic guanidine, and the bicyclic guanidine may comprise <NUM>,<NUM>,<NUM>-triazabicyclo[<NUM>. <NUM>]dec-<NUM>-ene ("TBD" or "BCG").

The guanidine may be present in the composition in an amount of at least <NUM>% by weight based on total weight of the composition, such as at least <NUM>% by weight, and may be present in an amount of no more than <NUM>% by weight based on total weight of the composition, such as no more than <NUM>%, such as no more than <NUM>%. The guanidine may be present in the composition in an amount of <NUM>% by weight to <NUM>% by weight based on total weight of the composition, such as <NUM>% by weight to <NUM>% by weight, such as <NUM>% by weight to <NUM>% by weight.

The guanidine particles may have a D90 particle size of <NUM> as measured by dynamic light scattering, such as a D90 particle size of <NUM>, such as a D90 particle size of <NUM>. Useful instruments useful for measuring the D90 include a LS <NUM><NUM> Laser Diffraction Particle Size Analyzer (available from Beckman Coulter) or similar instruments.

According to the present invention, the coating composition optionally may further comprise a second curing agent. The curing agent may be a latent curing agent, a blocked curing agent, an encapsulated curing agent, or combinations thereof.

Useful second curing agents may comprise amidoamine or polyamide catalysts, such as, for example, one of the Ancamide® products available from Air Products, amine, dihydrazide, or dicyandiamide adducts and complexes, such as, for example, one of the Ajicure® products available from Ajinomoto Fine Techno Company, <NUM>,<NUM>-dichlorophenyl-N,N-dimethylurea (A. Diuron) available from Alz Chem, or combinations thereof.

According to the present invention, when utilized, the second curing agent may be present in the coating composition in an amount of at least <NUM>% by weight based on the total composition weight, such as at least <NUM>%, such as at least <NUM>%, and in some cases may be present in the coating composition in an amount of no more than <NUM>% by weight based on the total composition weight, such as no more than <NUM>%, such as no more than <NUM>%. According to the present invention, when utilized, the second curing agent may be present in the coating composition in an amount from <NUM>% to <NUM>% by weight based on the total composition weight, such as from <NUM>% to <NUM>%.

According to the present invention, reinforcement fillers may optionally be added to the coating composition. Useful reinforcement fillers that may be introduced to the coating composition of the present invention to provide improved mechanical materials such as fiberglass, fibrous titanium dioxide, whisker type calcium carbonate (aragonite), and carbon fiber (which includes graphite and carbon nanotubes). In addition, fiber glass ground to <NUM> microns or wider and to <NUM> microns or longer may also provide additional tensile strength.

According to the present invention, organic and/or inorganic fillers, such as those that are substantially spherical, may optionally be added to the coating composition. Useful organic fillers that may be introduced include cellulose, starch, and acrylic. Useful inorganic fillers that may be introduced include borosilicate, aluminosilicate, and calcium carbonate. The organic and inorganic fillers may be solid, hollow, or layered in composition and may range in size from <NUM> to <NUM> in at least one dimension.

Optionally, according to the present invention, additional fillers, thixotropes, colorants, tints and/or other materials also may be added to the coating composition.

Useful thixotropes that may be used include untreated fumed silica and treated fumed silica, castor wax, clay, organo clay and combinations thereof. In addition, fibers such as synthetic fibers like Aramid® fiber and Kevlar® fiber, acrylic fibers, and/or engineered cellulose fiber may also be utilized.

Useful colorants, dyes, or tints may include red iron pigment, titanium dioxide, calcium carbonate, and phthalocyanine blue and combinations thereof.

Useful fillers that may be used in conjunction with thixotropes may include inorganic fillers such as inorganic clay or silica and combinations thereof.

Exemplary other materials that may be utilized include, for example, calcium oxide and carbon black and combinations thereof.

Such fillers, if present at all, may be present in an amount of no more than <NUM>% by weight based on total weight of the composition, such as no more than <NUM>% by weight, such as no more than <NUM>% by weight. Such fillers, if present at all, may be present in an amount of <NUM>% to <NUM>% by weight based on total weight of the composition, such as <NUM>% to <NUM>% by weight, such as <NUM>% to <NUM>% by weight.

Optionally, the composition may be substantially free, or essentially free, or completely free, of platy fillers such as mica, talc, pyrophyllite, chlorite, vermiculite, or combinations thereof.

Optionally, the composition may be substantially free, or essentially free, or completely free, of free radical initiators.

It has been surprisingly discovered that the addition of additives to the composition in an aggregate amount greater than <NUM>% by weight based on total composition weight significantly reduce the lap shear strength and displacement, such as greater than <NUM>% by weight, such as greater than <NUM>% by weight. That is, the composition may contain up to <NUM>% by weight additives based on total composition weight, such as up to <NUM>% by weight, such as up to <NUM>% by weight. In examples, the composition may be substantially free, or essentially free, or completely free, of additives. As used herein, the term "additives" refers to ingredients or components included in the coating composition in addition to the epoxy-containing component, the elastomeric particles, the guanidine curing component, the second curing agent, and the fillers described herein. Exemplary non-limiting examples of such additives include flexibilizers such as Flexibilzer® DY <NUM> from Huntsman Corporation, reactive liquid rubber, non-reactive liquid rubber, epoxy-amine adducts (such as those described above but, when present, different from the epoxy-containing component present in the coating composition), epoxy-thiol adducts, blocked isocyanates, capped isocyanates, epoxy-urethanes, epoxy-ureas, modified epoxies from Hexion, HELOXY™ modifiers from Hexion, adhesion promoters, silane coupling agents such as Silquest A-<NUM> from Momentive, flame retardants, colloidal silica such as NANOPOX® dispersions from Evonik, thermoplastic resins, acrylic polymer beads such as ZEFIAC® beads from AICA Kogyo Co, or combinations thereof.

The present invention also is directed to a method for treating a substrate comprising, or consisting essentially of, or consisting of, contacting at least a portion of a surface of the substrate with one of the compositions of the present invention described hereinabove. The composition may be cured to form a coating, layer or film on the substrate surface by exposure to an external energy source, as described herein. The coating, layer or film, may be, for example, a sealant or an adhesive.

The present invention is also directed to a method for forming a bond between two substrates for a wide variety of potential applications in which the bond between the substrates provides particular mechanical properties related to both lap shear strength and displacement. The method may comprise, or consist essentially of, or consist of, applying the composition described above to a first substrate; contacting a second substrate to the composition such that the composition is located between the first substrate and the second substrate; and curing the composition by exposure to an external energy source, as described herein. For example, the composition may be applied to either one or both of the substrate materials being bonded to form an adhesive bond therebetween and the substrates may be aligned and pressure and/or spacers may be added to control bond thickness. The composition may be applied to cleaned or uncleaned (i.e., including oily or oiled) substrate surfaces.

As stated above, the composition of the present disclosure also may form a coating, such as a sealant, on a substrate or a substrate surface. The coating composition may be applied to substrate surfaces, including, by way of non-limiting example, a vehicle body or components of an automobile frame or an airplane, or to armor assemblies such as those on a tank, or to protective clothing such as body armor, personal armor, suits of armor, and the like. The sealant formed by the composition of the present invention provides sufficient lap shear strength and displacement. The composition may be applied to cleaned or uncleaned (i.e., including oily or oiled) substrate surfaces. It may also be applied to a substrate that has been pretreated, coated with an electrodepositable coating, coated with additional layers such as a primer, basecoat, or topcoat. An external energy source may subsequently be applied to cure the coating composition, such as baking in an oven.

The composition described above may be applied alone or as part of a coating system that can be deposited in a number of different ways onto a number of different substrates. The system may comprise a number of the same or different layers and may further comprise other coating compositions such as pretreatment compositions, primers, and the like. A coating, film, layer or the like is typically formed when a composition that is deposited onto the substrate is at least partially cured by methods known to those of ordinary skill in the art (e.g., by exposure to thermal heating or actinic radiation).

The composition can be applied to the surface of a substrate in any number of different ways, non-limiting examples of which include brushes, rollers, films, pellets, pressure injectors, spray guns and applicator guns. Optionally, the substrate may be <NUM>% water break free. Optionally, the substrate may be non-water break free. As used herein, "water break free" means that water spreads evenly over the surface and does not bead up. As used herein, "non-water break free" means that water beads up over the surface.

After application to the substrate, the composition can be cured to form a coating, layer or film, such as using an external energy source such as an oven or other thermal means or through the use of actinic radiation. For example, the composition can be cured by baking and/or curing at elevated temperature, such as at a temperature of at least <NUM>, such as at least <NUM>, such as at least <NUM>, such as at least <NUM>, such as at least <NUM>, and in some cases at a temperature of no more than <NUM>, such as no more than <NUM>, such as no more than <NUM>, such as no more than <NUM>, such as no more than <NUM>, and in some cases at a temperature of from <NUM> to <NUM>, from <NUM> to <NUM>, from <NUM> to <NUM>, from <NUM> to <NUM>, and for any desired time period (e.g., from <NUM> minutes to <NUM> hours) sufficient to at least partially cure the coating composition on the substrate(s). The skilled person understands, however, that the time of curing varies with temperature. The coating, layer or film, may be, for example, a sealant or an adhesive, as described above.

As stated above, the present disclosure is directed to adhesive compositions that are used to bond together two substrate materials for a wide variety of potential applications in which the bond between the substrate materials provides particular mechanical properties related to combined lap shear strength and displacement. The adhesive composition may be applied to either one or both of the substrate materials being bonded such as, by way of non-limiting example, components of a vehicle. The pieces are aligned and pressure and/or spacers may be added to control bond thickness.

As stated above, the present disclosure also is directed to coating compositions that are used to coat a surface of a substrate to provide particular mechanical properties including strength and elongation. The coating composition may be applied to at least a portion of substrate surface, such as any of the substrates described herein.

It has been surprisingly discovered that the coating composition of the present invention provides, in an at least partially cured state, a coating that provides particular mechanical properties, including both increased strength and increased strain, displacement or elongation.

It has been surprisingly discovered that the coating compositions of the present invention, in the at least partially cured state (i.e., coatings of the present invention), have a hardness of greater than <NUM> N/mm<NUM> and an elongation of at least <NUM>%.

It has been surprisingly discovered that the coating compositions of the present invention, in the at least partially cured state (i.e., adhesives of the present invention), have both a shear stress of at least <NUM> MPa and a shear strain of at least <NUM>% measured in accordance with ISO <NUM>-<NUM>.

It also has been surprisingly discovered that the coating compositions of the present invention, in the at least partially cured state (i.e., adhesives of the present invention), have both a lap shear strength of greater than <NUM> MPa, measured according to ASTM D1002-<NUM> using <NUM>-T3 aluminum substrate of <NUM> thickness, as measured by an INSTRON <NUM> machine in tensile mode with a pull rate of <NUM> per minute, and a lap shear displacement at failure of at least <NUM>% of the overlap length.

The substrates that may be coated by the compositions of the present invention are not limited. Suitable substrates useful in the present invention include, but are not limited to, materials such as metals or metal alloys, ceramic materials such as boron carbide or silicon carbide, polymeric materials such as hard plastics including filled and unfilled thermoplastic materials or thermoset materials, or composite materials. Other suitable substrates useful in the present invention include, but are not limited to, glass or natural materials such as wood. For example, suitable substrates include rigid metal substrates such as ferrous metals, aluminum, aluminum alloys, magnesium titanium, copper, and other metal and alloy substrates. The ferrous metal substrates used in the practice of the present invention may include iron, steel, and alloys thereof. Non-limiting examples of useful steel materials include cold rolled steel, galvanized (zinc coated) steel, electrogalvanized steel, stainless steel, pickled steel, zinc-iron alloy such as GALVANNEAL, and combinations thereof. Combinations or composites of ferrous and non-ferrous metals can also be used. Aluminum alloys of the 1XXX, 2XXX, 3XXX, 4XXX, 5XXX, 6XXX, 7XXX, or 8XXX series as well as clad aluminum alloys and cast aluminum alloys of the A356, 1XX. X, or 8XXX series also may be used as the substrate. Magnesium alloys of the AZ31B, AZ91C, AM60B, or EV31A series also may be used as the substrate. The substrate used in the present invention may also comprise titanium and/or titanium alloys of grades <NUM>-<NUM> including H grade variants. Other suitable non-ferrous metals include copper and magnesium, as well as alloys of these materials. Suitable metal substrates for use in the present invention include those that are used in the assembly of vehicular bodies (e.g., without limitation, door, body panel, trunk deck lid, roof panel, hood, roof and/or stringers, rivets, landing gear components, and/or skins used on an aircraft), a vehicular frame, vehicular parts, motorcycles, wheels, and industrial structures and components. As used herein, "vehicle" or variations thereof includes, but is not limited to, civilian, commercial and military aircraft, and/or land vehicles such as cars, motorcycles, and/or trucks. The metal substrate also may be in the form of, for example, a sheet of metal or a fabricated part. It will also be understood that the substrate may be pretreated with a pretreatment solution including a zinc phosphate pretreatment solution such as, for example, those described in <CIT> and <CIT>, or a zirconium containing pretreatment solution such as, for example, those described in <CIT> and <CIT>. The substrate may comprise a composite material such as a plastic or a fiberglass composite. The substrate may be a fiberglass and/or carbon fiber composite. The compositions of the present invention are particularly suitable for use in various industrial or transportation applications including automotive, light and heavy commercial vehicles, marine, or aerospace.

Eight compositions were prepared from the mixture of ingredients shown in Table <NUM>. All compositions were prepared at an amine-hydrogen to epoxy equivalence ratio of <NUM>:<NUM>. Compositions I to IV, VII and VIII are comparative compositions.

Compositions I through VIII above were used to prepare thick adherend shear specimens. The thick adherends were <NUM>-T3 aluminum alloy machined to the dimensions specified for stepped adherends in Figure 1b of ISO <NUM>-<NUM>. The stepped end of each panel was grit blasted with <NUM>-grit aluminum oxide media (available from Grainger®). The grit blasted area was subsequently cleaned and deoxidized with ChemKleen 490MX (an alkaline cleaning solution available from PPG Industries, Inc. , Cleveland, OH). Composition was applied to both adherends covering the <NUM>×<NUM> bond area. The adherends were then joined securely in a machined fixture to ensure alignment and uniform bond length of <NUM> and bond thickness of <NUM>. Excess composition was cleaned from gaps and sides of stepped adherends and <NUM> thick polytetrafluoroethylene strips were inserted into the gaps to maintain a well-defined bond length. The fixture containing the thick adherend lap joints was then baked at <NUM> for <NUM> hours.

Baked thick adherend lap shear specimens were loaded onto an INSTRON <NUM> machine and a D5656 averaging extensometer from Epsilon Technology Corporation with a pin separation distance of <NUM> was placed around the bondline as specified in ISO <NUM>-<NUM>. Specimens were pulled at a rate of <NUM> per minute. Table <NUM> reports the measured values and those calculated based on the equations given in ISO <NUM>-<NUM>, using <NUM> GPa as the shear modulus of the adherents (MatWeb, LLC), with the strain energy density being the area under the stress-strain curve (<FIG>).

Lap shear specimens were prepared with compositions I through VIII above according to ASTM D1002-<NUM>. The substrate used was <NUM>-T3 aluminum alloy panels measuring <NUM>×<NUM>×<NUM>. One end of each panel, including the entire width (<NUM>) and at least <NUM> from one end, was grit blasted with <NUM>-grit aluminum oxide media (available from Grainger®). The grit blasted area was subsequently cleaned and deoxidized with ChemKleen 490MX (an alkaline cleaning solution available from PPG Industries, Inc. , Cleveland, OH). Composition was applied to one end of a panel covering the full <NUM> width and ≥<NUM> from one end. Glass beads averaging <NUM> in diameter were mixed into the composition in an amount of <NUM>% by weight based on total weight of the composition. A second grit blasted and cleaned aluminum panel was then placed over the composition layer in an end-to-end fashion, resulting in a bond area of <NUM>×<NUM>. Lap joints were secured with metal clips and excess composition cleaned, leaving a <NUM>° fillet. Lap joints were baked at <NUM> for <NUM> minutes, then the temperature was ramped to <NUM> at <NUM> per minute, and finally held at <NUM> for <NUM> minutes. The baked lap joint specimens were tested using an INSTRON <NUM> machine in tensile mode with <NUM> of aluminum substrate in each grip and at a pull rate of <NUM> per minute (in accordance with ASTM D1002-<NUM>).

The data from Example <NUM> demonstrate that inclusion of styrene butadiene particles having an average particle size of less than <NUM> resulted in an adhesive having improved shear properties (a maximum shear stress of at least <NUM> MPa and a shear strain of at least <NUM>%) and/or improved lap shear strength (at least <NUM> MPa) and improved lap shear displacement at failure (at least <NUM>% of the overlap, in this Example, <NUM>).

Example <NUM> (compositions IX to XIII) illustrates the effects of guanidine particle size and the effects of elastomeric particle concentration. The particle size of the guanidine were measured in their dry state, prior to mixing into the composition, using a LS <NUM><NUM> Laser Diffraction Particle Size Analyzer available from Beckman Coulter. Measurements were performed in triplicate using at least <NUM> grams of material and under ambient conditions. Dyhard <NUM> and Dyhard <NUM> were measured to have D90 particle sizes of <NUM> and <NUM>, respectively. Lap joints were prepared and tested in accordance with ASTM D1002-<NUM>, as described above. Composition XIII is a comparative composition.

The data from Example <NUM> illustrate that inclusion of a guanidine having a D90 particle size of less than <NUM> improves both the strength and displacement of the adhesive. The data also demonstrate that inclusion of greater than <NUM>% by weight of elastomeric particles based on total weight of the composition improves strength and displacement of the adhesive.

Example <NUM> illustrates the effect of the addition of mica to the composition. Lap joints were prepared, cured, and tested in accordance with ASTM D1002-<NUM>, as described above.

The data from Example <NUM> illustrate that the inclusion of mica in the composition reduces both lap shear strength and displacement of the adhesive.

Compositions XVI to XXI were prepared as described in Example <NUM> and as shown in Table <NUM>, but were prepared at an amine-hydrogen to epoxy equivalence ratio of <NUM>:<NUM>. Lap joints were prepared, cured, and tested as described in Example <NUM>.

The data from Example <NUM> illustrate that lap shear strength and displacement of the adhesive are reduced when the average epoxide functionality of the epoxy-containing component is greater than <NUM>.

Two compositions were prepared from the mixture of ingredients shown in Table <NUM>. All compositions were prepared at equal weight % dicyandiamide based on total composition weight. Lap joints were prepared, cured, and tested as described in Example <NUM>.

The data from Example <NUM> illustrate that inclusion of a flexibilizer in the composition does not improve lap shear strength and displacement of the adhesive (c. , strength and displacement of Composition XII, above).

Lap joint specimens were prepared with Scotch-Weld™ Epoxy Adhesive EC-<NUM> and with composition XIV (Example <NUM>, above) under the optimum conditions specified in the technical data sheet for EC-<NUM>, as follows. All <NUM>-T3 aluminum substrate (<NUM> thick) was prepared using an alkaline degrease and an acid etch. Lap joint specimens were prepared according to ASTM D1002-<NUM>. In order to maintain a bondline thickness within the specified optimal performance range for EC-<NUM> (<NUM> to <NUM> mil), <NUM> mil glass beads were added to each composition at <NUM>% by weight based on total weight of the composition. Lap joint specimens were baked at <NUM> for <NUM> minutes, the recommended cure cycle to obtain optimum bond properties of EC-<NUM>. Testing was conducted according to ASTM D1002-<NUM>.

The data from Example <NUM> illustrate the importance of including in the adhesive composition at least <NUM>% of elastomeric particles having an average particle size of less than <NUM> as measured by TEM.

Compositions I to VII were used to prepare thermosetting coatings on steel and aluminum. Coatings were prepared using a <NUM> draw down bar on acetone-cleaned metal substrate and were baked at <NUM> for <NUM> minutes, followed by a ramp to <NUM> at <NUM> per minute, and finally held at <NUM> for <NUM> minutes. Coatings prepared on cold rolled steel (<NUM> thick) were tested for hardness using a Fischerscope HM2000S at a rate of 100mN/<NUM>. Coatings prepared on T0-<NUM> aluminum (<NUM> thick) were used for reverse impact elongation testing according to ASTM D6905 with a Gardco GE Universal Impact Tester IM-<NUM>-GE/<NUM>. Results are compiled in Table <NUM> and are an average of at least three measurements.

Claim 1:
A composition, comprising:
an epoxy-containing component;
elastomeric particles in an amount of greater than <NUM>% by weight to <NUM>% by weight based on total weight of the composition, wherein at least <NUM>% by weight of the elastomeric particles comprise a styrene butadiene core based on total weight of the elastomeric particles; and
a curing component activatable by an external energy source, the curing component comprising at least one guanidine having a D90 particle size of <NUM> measured by dynamic light scattering.