Two-part structural adhesive

Abstract

Provided herein are two-part adhesive compositions that exhibit excellent adhesive strength after exposure to heat and moisture.

Description

[Technical field]

[0001] The present invention relates to the field of two-part epoxy adhesives, and in particular to toughened epoxy adhesives that are curable at ambient conditions and exhibit excellent mechanical properties. [Background technology]

[0002] Toughened two-part epoxy structural adhesives are widely used in the automotive and other industries for metal-to-metal and metal-to-other material bonding. Often, these structural adhesives must be highly resistant to failure during vehicle crash situations. This type of structural adhesive is sometimes called a "crash-resistant adhesive" or "CDA." This property is achieved by the presence of certain types of materials in the adhesive formulation. These materials are often called "tougheners." Tougheners have blocked functional groups that can be unblocked and reacted with the epoxy resin under the conditions of the curing reaction. This type of toughener is described, for example, in U.S. Pat. Nos. 5,202,390 and 5,278,257, WO 2005 / 118734, WO 2007 / 003650, WO 2012 / 091842, U.S. Patent Application Publication Nos. 2005 / 0070634 and 2005 / 0209401. Further details are described in EP 2006 / 0276601, EP-A-0308664, EP-1498441A, EP-A1728825, EP-A1896517, EP-A1916269, EP-A1916270, EP-A1916272 and EP-A-1916285.

[0003] U.S. Patent No. 9,181,463 describes epoxy adhesives containing toughening agents made by reacting poly(tetramethylene ether) glycol ("PolyTHF" or "PTMEG") with a diisocyanate, then chain extending the resulting prepolymer with O,O'-diallyl bisphenol A, followed by capping the isocyanate groups with a mono- or diphenol. Such adhesives are said to exhibit excellent storage stability and cure to form cured adhesives having excellent lap shear and impact peel strengths.

[0004] When tougheners with phenol-capped isocyanate end groups are formulated into epoxy resins, they react with hydroxyl or amine groups in the epoxy matrix during cure. The more end groups of the toughener that react, the better the mechanical properties of the cured adhesive.

[0005] Tougheners in such thermosetting structural adhesives typically contain a thermally labile capping group that cleaves at the elevated temperatures of cure, exposing reactive functional groups that allow the toughener to react and covalently bond with the epoxy matrix. Commonly used tougheners contain one or more reactive aliphatic isocyanate end groups capped with a phenol. At temperatures of 180°C, the reaction of the aliphatic isocyanate with the phenol is typically reversible, meaning that the phenol site is cleaved to regenerate the reactive isocyanate. This is often referred to as "deblocking" the toughener. [ka]

[0006] After deblocking, the free isocyanate reacts with the hydroxy groups of the epoxy resin or the amine groups of the curing agent to form an excellent interface between the toughener particles and the matrix, so that the toughener phase is dispersed and covalently bonded within the epoxy matrix at the same time.

[0007] Heating the assembly to about 180°C to cause deblocking is energy and time consuming and can lead to distortion if the bonded parts expand differently under heat. A toughening agent that can react with the epoxy matrix at lower temperatures is needed. Summary of the Invention

[0008] In a first aspect, provided herein is a two-part epoxy adhesive composition comprising: Component A: ai) at least one epoxy resin; aii) reacting at least one polyol and optionally a poly(butadiene) diol with a polyisocyanate in the presence of a polyurethane catalyst, optionally followed by chain extension with a diphenol, to produce a molecule of formula I: [ka] (In the formula, R 1 and R 2 are independently hydrogen and C 1 ~C 6 alkyl, n is an integer from 1 to 2, R 3 is C 1 ~C 6 (It is alkyl) a reactive toughener prepared by endcapping with; Component B: bi) one or more polyamines; bii) optionally one or more latent epoxy hardeners; biii) one or more epoxy curing catalysts; A two-part epoxy adhesive composition is provided which comprises:

[0009] In a second aspect, the present invention provides a cured adhesive obtained by mixing components A and B above and curing the resulting mixture.

[0010] In a third aspect, the present invention provides a method for producing a pharmaceutical composition comprising the steps of: 1. A two-part epoxy adhesive composition comprising: Component A: ai) at least one epoxy resin; aii) reacting at least one polyol and optionally a poly(butadiene) diol with a polyisocyanate in the presence of a polyurethane catalyst, optionally followed by chain extension with a diphenol, to produce a molecule of formula I: [ka] (In the formula, R 1 and R 2 are independently hydrogen and C 1 ~C 6 alkyl, n is an integer from 1 to 2, R 3 is C 1 ~C 6 (It is alkyl) a reactive toughener prepared by endcapping with; Component B: bi) one or more polyamines; bii) optionally one or more latent epoxy hardeners; biii) one or more epoxy curing catalysts; providing a two-part epoxy adhesive composition comprising: 2. Mixing components A and B to produce a mixture; 3. applying the mixture to a first substrate and / or a second substrate; 4. placing the substrates such that the substrate surfaces are in adhesive contact to sandwich a layer of the mixture therebetween; and 5. Allow the mixture to harden; A method for bonding two substrates is provided, comprising:

[0011] In a fourth aspect, the present invention provides a method for producing a pharmaceutical composition comprising the steps of: 1. A first substrate; 2. a second substrate; 3. A cured adhesive that bonds the first and second substrates; and 1. A bonded assembly comprising: the cured adhesive comprising the following components A and B: Component A: ai) at least one epoxy resin; aii) reacting at least one polyol and optionally a poly(butadiene) diol with a polyisocyanate in the presence of a polyurethane catalyst, optionally followed by chain extension with a diphenol, to produce a molecule of formula I: [ka] (In the formula, R 1 and R 2 are independently hydrogen and C 1 ~C 6 alkyl, n is an integer from 1 to 2, R 3 is C 1 ~C 6 (It is alkyl) a reactive toughener prepared by endcapping with; Component B: bi) one or more polyamines; bii) optionally one or more latent epoxy hardeners; biii) one or more epoxy curing catalysts; to produce a mixture, and curing the mixture to provide a bonded assembly. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The present inventors have surprisingly found that by reducing the toughener content in an epoxy adhesive, adhesive performance after exposure to heat and moisture is significantly improved.

[0013] Definitions and Abbreviations PTMEG Poly(tetramethylene oxide) glycol DGEBA Bisphenol A diglycidyl ether polyTHF Poly(tetramethylene oxide) glycol PBD Poly(butadiene)diol DBTL Dibutyltin dilaurate HDI Hexamethylene Diisocyanate CPEE Ethyl 2-oxocyclopentanecarboxylate PTHF Poly(tetrahydrofuran)

[0014] Polymer molecular weights reported herein are reported in Daltons (Da) as number or weight average molecular weights as determined by size exclusion chromatography (SEC).

[0015] The two-part adhesive of the present invention comprises component A (resin component) and component B (hardener component). During use, components A and B are mixed in the desired ratio and then applied to one or more substrates.

[0016] Ingredient A Component A comprises ai) at least one epoxy resin and aii) at least one reactive toughener.

[0017] Epoxy Resin Component A of the two-part adhesive of the present invention comprises at least one epoxy resin. Epoxy resins useful in the adhesive composition of the present invention include various curable epoxy compounds and combinations thereof. Useful epoxy resins include liquids, solids and mixtures thereof. Typically, the epoxy compounds are epoxy resins, also referred to as polyepoxides. Polyepoxides useful herein can be monomers (e.g., diglycidyl ether of bisphenol A, diglycidyl ether of bisphenol F, diglycidyl ether of tetrabromobisphenol A, novolac-based epoxy resins and trifunctional epoxy resins), higher molecular weight resins (e.g., diglycidyl ether of bisphenol A chain-extended with bisphenol A) or unsaturated monoepoxides polymerized into homopolymers or copolymers (e.g., glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, etc.). Most desirably, the epoxy compounds contain an average of at least one pendant or terminal 1,2-epoxy group (i.e., vicinal epoxy group) per molecule. The solid epoxy resins that can be used in the present invention can preferably include, or preferably be based primarily on, bisphenol A. Some preferred epoxy resins include, for example, DER330, DER331, and DER671, all of which are commercially available from The Dow Chemical Company.

[0018] One preferred epoxy resin has the general formula: [ka] (wherein n ranges from 0 to about 25). has.

[0019] Preferred epoxy resins have an epoxy equivalent weight in the range of about 170 to 195 g / mole.

[0020] Combinations of epoxy resins can be used to tailor the properties of the epoxy adhesive. In the compositions and methods of the present invention, the epoxy adhesive can include any amount of epoxy resin. Preferably, the liquid and / or solid epoxy resin constitutes 20% or more by weight of the epoxy adhesive, more preferably about 25% or more, 30% or more, or 35% or more by weight. Preferably, the liquid and / or solid epoxy resin constitutes 65% or less by weight of the epoxy adhesive, more preferably 55% or less, or 45% or less by weight. Other preferred amounts are shown in the examples. Ranges formed from pairs of these values ​​are also preferred, such as 25-35% by weight, 25-65% by weight, 30-38% by weight (adhesive AA).

[0021] When a combination of liquid and solid epoxy resins is used, any ratio can be used and can be determined by one skilled in the art. To obtain a suitable viscosity, it is usually preferred that the weight ratio of liquid epoxy resin to solid epoxy resin is greater than 50:50. The epoxy adhesive composition of the present invention preferably contains liquid and solid epoxy resins in a ratio of 55:45 or more, 65:35 or more, or 70:30 or more. The epoxy adhesive composition of the present invention preferably contains liquid and solid epoxy resins in a ratio of 100:0 or less, 99:1 or less, 90:10 or less, or 85:10 or less. Other preferred ratios are shown in the examples. Ranges formed from these pairs of values ​​(e.g., 50:50 to 100:0, 65:35 to 82:18 (adhesive AU)) are also preferred.

[0022] Preferred epoxy resins include the following: Epoxy Liquid reaction products of epichlorohydrin and bisphenol A, e.g. DER331, having an epoxide equivalent weight (measured according to ASTM D-1652) of 1.182-192 g / eq, an epoxide percentage (measured according to ASTM D-1652) of 22.4-23.6%, an epoxide group content (measured according to ASTM D-1652) of 5200-5500 mmol / kg, and a viscosity at 25°C (measured according to ASTM D-445) of 4000-14000 mPas; Epoxy A solid epoxy resin which is a low molecular weight solid reaction product of epichlorohydrin and bisphenol A, e.g. DER671, having an epoxide equivalent weight (measured according to ASTM D-1652) of 2.475-550 g / eq, an epoxide percentage (measured according to ASTM D-1652) of 7.8-9.1%, an epoxide group content (measured according to ASTM D-1652) of 1820-2110 mmol / kg, and a melt viscosity at 150°C (measured according to ASTM D-4287) of 400-950 mPas; 3. Mixture of Epoxy 1 and Epoxy 2.

[0023] Particularly preferred is Epoxy 1.

[0024] The epoxy resin is preferably present in the adhesive of the present invention at 50 to 80 wt %, more preferably 55 to 75 wt %, and especially preferably 60 to 72 wt %, based on the total weight of component A of the adhesive.

[0025] In a particularly preferred embodiment, the epoxy resin is Epoxy 1, used at 62-72% by weight, based on the total weight of component A of the adhesive.

[0026] Reactive Tougheners Component A of the two-part adhesive of the present invention contains a specific toughening agent.

[0027] The toughening agents used in the compositions of the present invention are prepared by reacting at least one polyol and optionally a poly(butadiene) diol with a polyisocyanate in the presence of a polyurethane catalyst, optionally followed by chain extension with a diphenol and the formation of a molecule of formula I: [ka] (In the formula, R 1 and R 2 are independently hydrogen and C 1 ~C 6 alkyl, n is an integer from 1 to 2, R 3 is C 1 ~C 6It is a reactive toughening agent prepared by endcapping with an alkyl group.

[0028] In a preferred embodiment, R 1 and R 2 are independently H and C 1 ~C 4 Alkyl, more preferably H and C 1 ~C 2 alkyl, particularly preferably R 1 and R 2 is H.

[0029] In a preferred embodiment, R 3 is C 1 ~C 4 alkyl, more preferably C 1 ~C 2 It is an alkyl.

[0030] In a preferred embodiment, n is 1.

[0031] In another preferred embodiment, R 1 and R 2 is H and R 3 is ethyl or methyl, in particular ethyl, and n is 1. In a particularly preferred embodiment, the capping molecule is CPEE.

[0032] In a preferred embodiment, the PBD is included in the toughening agent backbone.

[0033] In another preferred embodiment, chain extension is carried out with diphenols.

[0034] In another preferred embodiment, a PBD is included and chain extended with a diphenol.

[0035] In another preferred embodiment, no PBD is included.

[0036] In another preferred embodiment, no chain extension is performed.

[0037] In another preferred embodiment, no PBD is included and no chain extension is performed.

[0038] The at least one polyol is preferably a diol or triol, or a mixture of both. Diols are particularly preferred. In a preferred embodiment, the at least one polyol is a poly(alkylene oxide) diol. A preferred poly(alkylene oxide) diol is poly(C 2 ~C 6 The poly(alkylene oxide) diol is preferably selected from poly(tetramethylene oxide) diol ("PTMEG"), poly(trimethylene oxide) diol ("PO3G") and mixtures thereof. The poly(alkylene oxide) diol preferably has a molecular weight in the range of 1,000 to 2,500 Da, more preferably 1,000 to 2,000 Da. PTMEG is particularly preferred. Preferably, PTMEG has a molecular weight in the range of 1,000 to 2,500 Da, more preferably 1,000 to 2,000 Da.

[0039] The PBD preferably has a molecular weight in the range of 2,000 to 3,500 Da, more preferably 2,800 Da.

[0040] The polyisocyanate is not particularly limited. Aliphatic diisocyanates and alicyclic diisocyanates are preferred, with 1,6-hexamethylene diisocyanate ("HMDI" or "HDI") and isophorone diisocyanate (IPDI) being specific examples. HMDI is particularly preferred.

[0041] The polyurethane catalyst is not particularly limited. Dibutyltin dilaurate ("DBTL") and metal carboxylates, such as bismuth carboxylate and / or zinc carboxylate, are particularly preferred. The catalyst is preferably used at 0.01 to 0.5 wt %, more preferably 0.1 wt %, based on the total weight of the toughening agent. In a preferred embodiment, the catalyst is a mixture of bismuth and zinc salts of carboxylates, and is used at 0.1 wt %, based on the total weight of the toughening agent composition.

[0042] Optional chain extension is carried out using a diphenol. O,O'-diallyl bisphenol A ("ODBA") is particularly preferred. The diphenol is preferably used in an amount of 2 to 10% by weight, more preferably 5 to 8% by weight, and especially preferred 7% by weight, based on the total weight of the toughening agent. Alternatively, the chain extender can be used in a molar ratio to the polyol of 0:1 to 1:1, more preferably 0:1 to 0.8:1, and especially preferred 0.6:1 to 0.8:1.

[0043] The reaction of the diol, polyisocyanate, and diphenol chain extender (if used) terminates the pre-capping molecule with NCO groups, which are then end-capped with the molecule of formula I using a suitable catalyst, such as at least one metal carboxylate, particularly a zinc and / or bismuth salt of a carboxylate.

[0044] The toughening agent preferably comprises 40-90% by weight, more preferably 45-85% by weight, more preferably 50-85% by weight of a polyol, in particular a poly(alkylene oxide) diol, based on the total weight of the toughening agent. Particularly preferably, the toughening agent comprises 40-90% by weight, more preferably 45-85% by weight, more particularly preferably 50-85% by weight of PTMEG, based on the total weight of the toughening agent. PTMEG having molecular weights of 1,000 Da, 1,400 Da, and 2,000 Da are particularly preferred.

[0045] When present, the PBD is preferably present in the toughening agent at 10 to 25 wt %, more preferably 12 to 18 wt % PBD, based on the total weight of the toughening agent, with PBD having a molecular weight of 2,800 Da being especially preferred.

[0046] A preferred toughening agent comprises 50-85% by weight PTMEG, 7-20% by weight HDI, and 5-15% by weight of a capping group, especially CPEE.

[0047] A preferred toughening agent comprises 50-85% by weight PTMEG, 10-20%, more preferably 12-18% by weight PBD, 7-20% by weight HDI and 5-15% by weight of a capping group, especially CPEE.

[0048] Some examples of preferred toughening agents are made by reacting the following ingredients (weight percentages are based on the total weight of the toughening agent):

[0049] [Table A]

[0050] A preferred method for producing the toughening agent is the following process: 1. First reaction step: Heat a polyol, preferably a poly(alkylene oxide) diol (more preferably PTMEG) and PBD (if used) to 120-130°C. Heat the mixture under vacuum for 25-35 minutes. Cool the mixture to 50-70°C. When the temperature reaches 50-70°C, add a diisocyanate (preferably HDI) and mix the mixture for 2-5 minutes. Then add a polyurethane catalyst (e.g. a metal salt of a carboxylate such as bismuth carboxylate and / or zinc carboxylate) and react the mixture at 75-90°C (bath temperature) for 40-50 minutes under a neutral atmosphere (e.g. nitrogen or argon). 2. Second reaction step: Chain extender (if used) is added and the mixture is stirred under a neutral atmosphere (e.g. nitrogen or argon) at 85-95°C (bath temperature) for 50-70 minutes. 3. Third reaction step: An end-capping molecule of formula I (e.g., CPEE) is added and the mixture is stirred for 80-95 min at 85-95 °C (bath temperature) in a neutral atmosphere (e.g., nitrogen or argon). The mixture is stirred for 10 min at 95 °C under vacuum for degassing.

[0051] Particularly preferred toughening agents are made using the process described above, using the ingredients listed in Table A (weight percentages are based on the total weight of the toughening agent).

[0052] Other ingredients of ingredient A Component A may contain additional optional components such as: · One or more silane-based adhesion promoters, such as tris(diethylene glycol methyl ether) silyl propylene glycidyl ether. Mono-, di-, and trifunctional epoxy reactive diluents, such as diphenols, monophenols, e.g., cardanol, C 12~14 -monoglycidyl ethers of alcohols, (trimethylolpropane triglycidyl ether) resins, and diglycidyl ether of cyclohexanedimethanol. Plasticizers such as phthalates and dialkylnaphthalenes, in particular dialkyl phthalates, for example diisononyl phthalate, and dialkylnaphthalenes such as diisopropylnaphthalene. Fillers, e.g. calcium carbonate, TiO 2 , fumed silica, wollastonite, glass (in fibrous, microspherical and flake form), carbon fiber, graphite. · Thermally conductive fillers such as aluminum hydroxide (ATH), alumina, spherical alumina, aluminum, zinc oxide, boron nitride, diamond, or combinations thereof; may include.

[0053] Component B Component B includes bi) one or more polyamines, bii) optionally one or more latent epoxy curing agents, and bii) one or more epoxy curing catalysts.

[0054] Polyamines Component B comprises at least one polyamine capable of crosslinking with the epoxy groups on the epoxy resin. Polyamines include molecules with two or more amine groups. In a preferred embodiment, the polyamine has an amine functionality of 3 or more, more preferably greater than 10.

[0055] In another preferred embodiment, the polyamine comprises at least one molecule having an amine functionality of 10 or greater in combination with one or more diamines.

[0056] In another preferred embodiment, the polyamine comprises at least one molecule having an amine functionality of 10 or greater in combination with one or more triamines and one or more diamines.

[0057] Preferred polyamines include polymeric amines, low molecular weight amines, and combinations thereof.

[0058] In a preferred embodiment, the polyamine includes polyetheramine, i.e., a molecule having a polyether backbone with terminal amine groups. Also preferred is the reaction product of a stoichiometric excess of an amine prepolymer with an epoxy resin. The amine prepolymer may be any amine prepolymer having at least two amine groups to allow crosslinking to occur. The amine prepolymer contains primary and / or secondary amine groups, preferably primary amine groups. Suitable amine prepolymers include polyether diamines and polyether triamines and mixtures thereof.

[0059] The polyetheramines may be linear, branched, or mixed. Branched polyetheramines are preferred. Polyetheramines of any molecular weight may be used, with molecular weights in the range of 200 to 6000 or greater being suitable. The molecular weight may be greater than 1000, or more preferably greater than 3000. Molecular weights of 3000 or 5000 are preferred.

[0060] Examples of suitable commercially available polyetheramines include the following:

[0061] [Table B]

[0062] In a preferred embodiment, the polyamine of Component B comprises a mixture of Lupasol P, Jeffamine T-403, Jeffamine D-400, Jeffamine D-2000, and 4,7,10-trioxatridecane-1,13-diamine.

[0063] In another preferred embodiment, the polyamine of Component B comprises a mixture of Lupasol P, Jeffamine T-403, TETA, and 4,7,10-trioxatridecane-1,13-diamine.

[0064] The concentration of polyamine in Component B depends on the degree of cure desired in the cured adhesive, and also on the desired mix ratio of Components A and B. In one preferred embodiment where the ratio of Component A to Component B is 2:1, the total polyamine content of Component B is 30-70% by weight, more preferably 40-65% by weight, based on the total weight of Component B.

[0065] Latent epoxy hardener The adhesive may optionally include a latent hardener.

[0066] Suitable latent hardeners include materials such as boron trichloride / amine and boron trifluoride / amine complexes, melamine, diallylmelamine, guanamines such as dicyandiamide, methylguanidine, dimethylguanidine, trimethylguanidine, tetramethylguanidine, methylisobiguanidine, dimethylisobiguanidine, tetramethylisobiguanidine, heptamethylisobiguanidine, hexamethylisobiguanidine, acetoguanamine and benzoguanamine, aminotriazoles such as 3-amino-1,2,4-triazole, hydrazides such as adipic acid dihydrazide, stearic acid dihydrazide, isophthalic acid dihydrazide, semicarbazide, cyanoacetamide, and aromatic polyamines such as aminodiphenylsulfone. Dicyandiamide is a particularly preferred hardener.

[0067] The latent curing agent, if present, is used in an amount sufficient to cure the adhesive. Typically, a curing agent is provided that is sufficient to consume at least 80% of the epoxide groups present in the composition. A large excess beyond the amount necessary to consume all of the epoxide groups is usually not required. Preferably, the curing agent constitutes at least about 1.5 weight percent, more preferably at least about 2.5 weight percent, and even more preferably at least 3.0 weight percent of Component B. The curing agent preferably constitutes at most about 10 weight percent, more preferably at most about 8 weight percent, and most preferably at most about 5 weight percent of Component B.

[0068] In a preferred embodiment, the latent epoxy curing agent is dicyandiamide. The constant of the epoxy / dicyandiamide ratio (EP / Dicy ratio) is calculated by the ratio of the number of epoxide groups per kg to the number of dicy molecules per kg in the formulation. Preferably, dicyandiamide is present in an amount that gives an epoxy / dicyandiamide ratio of about 5.

[0069] Epoxy curing catalyst The adhesive composition of the present invention includes an epoxy curing catalyst.

[0070] The epoxy curing catalyst is one or more substances that catalyze the reaction of the curing agent with the epoxy resin. Among the preferred epoxy catalysts are p-chlorophenyl-N,N-dimethylurea (monuron), 3-phenyl-1,1-dimethylurea (fenuron), 3,4-dichlorophenyl-N,N-dimethylurea (diuron), N-(3-chloro-4-methylphenyl)-N',N'-dimethylurea 25 (chlorotoluron), tert-acrylic- or alkylenediamine (such as benzyldimethylamine), 2,4,6-tris(dimethylaminomethyl)phenol, piperidine or its derivatives, various aliphatic urea compounds (such as those described in European Patent No. 1916272); C 1 ~C 12Suitable are alkylene imidazoles or N-arylimidazoles (such as 2-ethyl-2-methylimidazole) or N-butylimidazole and 6-caprolactam, 2,4,6-tris(dimethylaminomethyl)phenol incorporated in a poly(p-vinylphenol) matrix (such as those described in EP 0197892) or 2,4,6-tris(dimethylaminomethyl)phenol incorporated in a novolac resin (such as those described in U.S. Pat. No. 4,701,378). Particularly preferred is tris-2,4,6-tris(dimethylaminomethyl)phenol incorporated in a poly(p-vinylphenol) polymer matrix.

[0071] The epoxy curing catalyst may constitute, for example, 1 to 20% by weight, more preferably 8 to 16% by weight, and particularly preferably 10 to 14% by weight, based on the total weight of component B.

[0072] In a preferred embodiment, the epoxy curing catalyst is 2,4,6-tris(dimethylaminomethyl)phenol incorporated into a poly(p-vinylphenol) polymer matrix and is used in an amount of 10 to 14 wt%, more preferably 12 wt%, based on the total weight of component B.

[0073] Other ingredients of component B Component B may contain additional optional components such as: TiO 2 , fillers such as calcium carbonate, fumed silica, wollastonite, glass (in fibrous, microspherical, or flake form); Rheology modifiers such as surfactants, e.g. non-ionic fluorosurfactants; Monofunctional, difunctional, and trifunctional epoxy reactive diluents, such as diphenols, monophenols, such as cardanol, C 12~14 - monoglycidyl ethers of alcohols, (trimethylolpropane triglycidyl ether) resins, and diglycidyl ethers of cyclohexanedimethanol; Plasticizers such as phthalates and dialkylnaphthalenes, especially dialkyl phthalates, for example diisononyl phthalate, and dialkylnaphthalenes such as diisopropylnaphthalene; a thermally conductive filler such as aluminum hydroxide (ATH), alumina, spherical alumina, aluminum, zinc oxide, boron nitride, diamond, or combinations thereof; may include.

[0074] Hardened adhesive In one aspect, the present invention provides a cured adhesive obtained by mixing components A and B described herein and curing the resulting mixture.

[0075] Components A and B can be mixed by any method that provides a homogenous mixture relatively quickly. In a preferred embodiment, mixing is accomplished using a static mixer as components A and B are dispensed through a nozzle.

[0076] The mixing ratio of component A to component B is determined by the concentration of reactive functional groups in components A and B, and the degree of crosslinking desired. In a preferred embodiment, the ratio of A:B is 1:1 or 2:1.

[0077] An advantage of the adhesive of the present invention is that curing can occur at relatively low temperatures, in a preferred embodiment below 40°C, more preferably below 30°C.

[0078] Method of bonding substrates In another aspect, the present invention provides a method for producing a composition comprising: 1. A two-part epoxy adhesive composition comprising: Component A: ai) at least one epoxy resin; aii) reacting at least one poly(alkylene oxide) diol and optionally a poly(butadiene) diol with a polyisocyanate in the presence of a polyurethane catalyst, optionally followed by chain extension with a diphenol, to produce a molecule of formula I: [ka] (In the formula, R 1 and R 2 are independently hydrogen and C 1 ~C 6 alkyl, n is an integer from 1 to 2, R 3 is C 1 ~C 6 (It is alkyl) a reactive toughener prepared by endcapping with; Component B: bi) one or more polyamines; bii) optionally one or more latent epoxy hardeners; biii) one or more epoxy curing catalysts; providing a two-part epoxy adhesive composition comprising: 2. Mixing components A and B to produce a mixture; 3. applying the mixture to a first substrate and / or a second substrate; 4. placing the substrates such that the substrate surfaces are in adhesive contact to sandwich a layer of the mixture therebetween; and 5. Allow the mixture to harden; The present invention provides a method for bonding two substrates, comprising:

[0079] The adhesives of the present invention are particularly suitable for bonding metal to metal, especially steel, aluminum, magnesium, titanium, nickel plated steel, stainless steel, plated steels typically used in the automotive industry, such as zinc plated steel, and zinc magnesium plated steel.

[0080] In a preferred embodiment, the first and second substrates are both metal, in particular steel or aluminium.

[0081] Components A and B can be mixed by any method that provides a homogenous mixture relatively quickly. In a preferred embodiment, mixing is accomplished using a static mixer as components A and B are dispensed through a nozzle.

[0082] The mixing ratio of component A to component B is determined by the concentration of reactive functional groups in components A and B, and the degree of crosslinking desired. In a preferred embodiment, the ratio of A:B is 1:1 or 2:1.

[0083] An advantage of the adhesives of the present invention is that curing can occur at relatively low temperatures, in preferred embodiments below 40° C., more preferably below 30° C. It is of course possible to reduce cure times by heating above these temperatures, and use of the adhesives of the present invention in such a manner is also envisaged.

[0084] Examples of Preferred Adhesive Compositions of the Invention 1. A two-part epoxy adhesive composition comprising: Component A: ai) at least one epoxy resin; aii) reacting at least one polyol, preferably a poly(alkylene oxide) diol and optionally a poly(butadiene) diol, with a polyisocyanate in the presence of a polyurethane catalyst, optionally followed by chain extension with a diphenol, to produce a molecule of formula I: [ka] (In the formula, R 1 and R 2 are independently hydrogen and C 1 ~C 6 alkyl, n is an integer from 1 to 2, R 3 is C 1 ~C 6 (It is alkyl) a reactive toughener prepared by endcapping with; Component B: bi) one or more polyamines; bii) optionally one or more latent epoxy hardeners; biii) one or more epoxy curing catalysts; 1. A two-part epoxy adhesive composition comprising: 2. The composition of embodiment 1, wherein the at least one epoxy resin comprises an epoxy resin selected from those having an epoxy equivalent weight in the range of about 170 to 195 g / mole. 3. The composition of any one of the preceding claims, wherein the at least one epoxy resin comprises a liquid reaction product of epichlorohydrin and bisphenol A having an epoxide equivalent weight (measured according to ASTM D-1652) of 182 to 192 g / eq. 4. The composition of embodiment 1, 2, or 3, wherein the at least one epoxy resin comprises an epoxy having an epoxide percent fraction (measured according to ASTM D-1652) of 22.4 to 23.6%, an epoxide group content (measured according to ASTM D-1652) of 5200 to 5500 mmol / kg. 5. The composition of any one of the preceding embodiments, wherein the at least one epoxy resin comprises an epoxy having a viscosity of 4000 to 14000 mPas at 25° C. (measured according to ASTM D-445). 6. The composition according to any one of the preceding embodiments, wherein the at least one epoxy resin is used in an amount of 50 to 80% by weight, more preferably 55 to 75% by weight, and particularly preferably 60 to 72% by weight, based on the total weight of component A of the adhesive. 7.R 1 and R 2 But H and C 1 ~C 4 The composition of any one of embodiments 1-6, wherein the alkyl is independently selected from the group consisting of aryl, aryl, aryl and alkyl. 8.R 1 and R 2 But H and C 1 ~C 2 The composition of any one of embodiments 1-7, wherein the is independently selected from alkyl. 9.R 2 and R 2 The composition of any one of embodiments 1-8, wherein 10.R 3 C 1 ~C 4 The composition of any one of embodiments 1-9, wherein the alkyl is alkyl. 11.R 3 C 1 ~C 2 The composition of any one of embodiments 1-10, wherein the alkyl is alkyl. 12.R 3 The composition of any one of embodiments 1-11, wherein is ethyl. 13. The composition according to any one of the preceding embodiments, wherein n is 1. 14. The composition of any one of the preceding embodiments, wherein the end-capping molecule is ethyl-2-oxocyclopentanecarboxylate. 15. The poly(alkylene oxide) diol used in the toughening agent is poly(C 2 ~C 6 The composition of any one of embodiments 1 to 14, wherein the diol is selected from the group consisting of alkylene oxide (alkylene oxide) diols. 16. The composition of any one of the preceding embodiments, wherein the poly(alkylene oxide) diol used in the toughening agent is selected from poly(tetramethylene oxide) diol ("PTMEG"), poly(trimethylene oxide) diol ("PO3G"), and mixtures thereof. 17. The composition of any one of the preceding embodiments, wherein the poly(alkylene oxide) diol has a molecular weight in the range of 1,000 to 2,500 Da. 18. The composition of any one of the preceding embodiments, wherein the poly(alkylene oxide) diol has a molecular weight of 1,000 Da, 1,400 Da, or 2,000 Da, or mixtures thereof are used. 19. The composition of any one of the preceding embodiments, wherein the poly(alkylene oxide) diol is PTMEG having a molecular weight in the range of 1,000 to 2,500 Da. 20. The composition of any one of the preceding embodiments, wherein poly(butadiene) diol ("PBD") is used as the toughening agent. 21. The composition of embodiment 20, wherein the PBD has a molecular weight in the range of 2,000 to 3,500 Da. 22. The composition of embodiment 20, wherein the PBD has a molecular weight of 2,800 Da. 23. The composition of any one of the preceding embodiments, wherein the at least one poly(alkylene oxide) diol is PTMEG and PBD is included in the toughener backbone. 24. The composition of any one of the preceding embodiments, wherein the at least one polyisocyanate used in the toughening agent is an aliphatic diisocyanate. 25. The composition of any one of the preceding embodiments, wherein the at least one polyisocyanate is selected from 1,6-hexamethylene diisocyanate ("HMDI"), isophorone diisocyanate (IPDI), and mixtures thereof. 26. The composition of any one of the preceding embodiments, wherein the at least one polyisocyanate is hexamethylene diisocyanate ("HMDI"). 27. The composition according to any one of the preceding embodiments, wherein the chain extension is carried out using a diphenol. 28. The composition of embodiment 27, wherein the diphenol is O,O'-diallyl bisphenol A. 29. The composition of any one of the preceding embodiments, wherein the polyurethane catalyst is selected from dibutyltin dilaurate ("DBTL") and metal carboxylates, such as bismuth carboxylates and / or zinc carboxylates. 30. The composition of any one of the preceding embodiments, wherein the polyurethane catalyst is used at 0.01 to 0.5 wt. %, more preferably 0.1 wt. %, based on the total weight of the toughening agent. 31. The composition of any one of the preceding embodiments, wherein the polyurethane catalyst is a mixture of a bismuth carboxylate and a zinc carboxylate. 32. The composition of any one of the preceding embodiments, wherein the toughening agent comprises 40 to 90 weight percent of poly(alkylene oxide) diol, based on the total weight of the toughening agent. 33. The composition of any one of the preceding embodiments, wherein the toughening agent comprises 45 to 85 weight percent of poly(alkylene oxide) diol, based on the total weight of the toughening agent. 34. The composition of any one of the preceding embodiments, wherein the toughening agent comprises 50 to 85 weight percent of poly(alkylene oxide) diol, based on the total weight of the toughening agent. 35. The composition of any one of the preceding embodiments, wherein the toughening agent comprises 50-85 wt. % PTMEG, 7-20 wt. % HDI, and 5-15 wt. % end-capping group, particularly CPEE, based on the total weight of the toughening agent. 36. The composition of any one of the preceding embodiments, wherein the toughening agent comprises 50-85 wt. % PTMEG, 8-20 wt. % PBD, 7-20 wt. % HDI, and 5-15 wt. % end-capping group, particularly CPEE, based on the total weight of the toughening agent. 37. The composition of any one of the preceding embodiments, wherein the at least one polyamine in component B has an amine functionality of 2 or greater. 38. The composition of any one of the preceding embodiments, wherein the at least one polyamine in component B comprises at least one molecule having an amine functionality of 10 or greater in combination with one or more diamines. 39. The composition of any one of the preceding embodiments, wherein the at least one polyamine in component B comprises at least one polyetheramine. 40. The composition of any one of embodiments 1-39, wherein the at least one polyamine in component B contains primary amine groups and secondary amine groups. 41. The composition of any one of embodiments 1-40, wherein the at least one polyamine in component B comprises a primary amine group. 42. The at least one polyamine in component B is [Table X] and any mixture of the above. 43. The composition of any one of the preceding embodiments, wherein the at least one polyamine in component B comprises a mixture of Lupasol P, Jeffamine T-403, Jeffamine D-400, Jeffamine D-2000, and 4,7,10-trioxatridecane-1,13-diamine. 44. The composition of any one of the preceding embodiments, wherein the at least one polyamine in component B comprises a mixture of Lupasol P, Jeffamine T-403, TETA, and 4,7,10-trioxatridecane-1,13-diamine. 45. The composition of any one of the preceding embodiments, wherein the latent epoxy curing agent is selected from boron trichloride / amine and boron trifluoride / amine complexes, melamine, diallylmelamine, guanamines such as dicyandiamide, methylguanidine, dimethylguanidine, trimethylguanidine, tetramethylguanidine, methylisobiguanidine, dimethylisobiguanidine, tetramethylisobiguanidine, heptamethylisobiguanidine, hexamethylisobiguanidine, acetoguanamine and benzoguanamine, aminotriazoles such as 3-amino-1,2,4-triazole, hydrazides such as adipic dihydrazide, stearic dihydrazide, isophthalic dihydrazide, semicarbazide, cyanoacetamide, and aromatic polyamines such as aminodiphenylsulfone. 46. ​​The composition of any one of embodiments 1-45, wherein the latent epoxy curing agent is dicyandiamide. 47. The epoxy curing catalyst is p-chlorophenyl-N,N-dimethylurea (monuron), 3-phenyl-1,1-dimethylurea (fenuron), 3,4-dichlorophenyl-N,N-dimethylurea (diuron), N-(3-chloro-4-methylphenyl)-N',N'-dimethylurea 25 (chlortoluron), tert-acryl- or alkylenediamine (benzyldimethylamine, etc.), 2,4,6-tris(dimethylaminomethyl)phenol, piperidine or its derivatives, C 1 ~C 1247. The composition of any one of the preceding embodiments, wherein the alkylene imidazole or N-arylimidazole (such as 2-ethyl-2-methylimidazole), or N-butylimidazole and 6-caprolactam, 2,4,6-tris(dimethylaminomethyl)phenol incorporated in a poly(p-vinylphenol) matrix (such as those described in EP 0197892), or 2,4,6-tris(dimethylaminomethyl)phenol incorporated in a novolac resin (such as those described in U.S. Pat. No. 4,701,378). 48. The composition of any one of embodiments 1-47, wherein the epoxy curing catalyst is tris-2,4,6-tris(dimethylaminomethyl)phenol. 49. The composition according to any one of the preceding embodiments, wherein the epoxy curing catalyst is present in an amount of 1 to 20% by weight, more preferably 8 to 16% by weight, and particularly preferably 10 to 14% by weight, based on the total weight of component B. 50. The composition of any one of the preceding embodiments, wherein the epoxy curing catalyst is 2,4,6-tris(dimethylaminomethyl)phenol incorporated into a poly(p-vinylphenol) polymer matrix and is used in an amount of 10 to 14% by weight, more preferably 12% by weight, based on the total weight of component B. 51. A method for bonding two substrates, comprising: 1. Preparing a two-part epoxy adhesive composition according to any one of embodiments 1 to 50; 2. Mixing components A and B to produce a mixture; 3. applying the mixture to a first substrate and / or a second substrate; 4. placing the substrates such that the substrate surfaces are in adhesive contact to sandwich a layer of the mixture therebetween; and 5. Curing the mixture; The method includes: 52. The method of embodiment 51, wherein the first and second substrates are metals independently selected from steel and aluminum. 53. The method according to embodiment 51 or 52, wherein the mixing ratio of component A to component B is 1:1 or 2:1. 54. The method of embodiment 51, 52, or 53, wherein curing is carried out at a temperature below 40° C.

[0085] Effect of the Invention After curing at room temperature for 7 days, the adhesive composition of the present invention exhibits excellent impact peel strength, preferably 15 N / mm or greater, at 23° C. on steel.

[0086] After curing at room temperature for 7 days, the adhesive composition of the present invention exhibits excellent T-peel strength, preferably 3.5 N / mm or greater, at 23° C. on steel.

[0087] After curing at room temperature for 7 days, the adhesive composition of the present invention exhibits an excellent E modulus, preferably 1,000 MPa or more, more preferably 1,200 MPa or more.

[0088] After curing at room temperature for 7 days, the adhesive composition of the present invention exhibits excellent tensile strength, preferably 23 MPa or more, more preferably 25 MPa or more. EXAMPLES

[0089] [Table 1A]

[0090] [Table 1B]

[0091] [Table 1C]

[0092] DER™ 331™ liquid epoxy resin is the liquid reaction product of epichlorohydrin and bisphenol A having an epoxide equivalent weight (measured in accordance with ASTM D-1652) of 182-192 g / eq, an epoxide percentage (measured in accordance with ASTM D-1652) of 22.4-23.6%, an epoxide group content (measured in accordance with ASTM D-1652) of 5200-5500 mmol / kg, and a viscosity at 25° C. (measured in accordance with ASTM D-445) of 11000-14000 mPas.

[0093] Manufacture of toughening agents The toughening agent was produced from the ingredients in Table 2.

[0094] [Table 2]

[0095] Description of the manufacturing process of the reference toughener Comp. A (X) (poly THF) was placed in a laboratory reactor and heated to 130° C. under stirring and vacuum. The mixture was then cooled to 70° C. with stirring. The vacuum was released and Comp. B (HDI) was added. The mixture was stirred under nitrogen for 2 minutes, after which Comp. E (DBTL) was added. The mixture was allowed to react for 45 minutes with stirring and nitrogen at a bath temperature of 85° C. The isocyanate content was measured and if it was close to 0%, the mixture was allowed to cool to 70° C. with stirring under nitrogen. When the temperature reached 70° C., the premixed Comp. C (HDI) and Comp H (DER330) were added together to the laboratory reactor. The mixture was allowed to react for 45 minutes with stirring and nitrogen at a bath temperature of 85° C. The isocyanate content was checked (Table 2 “NCO 2 nd RS"). If the NCO content was close to the expected value, Comp. F (Cardolite) was added. The mixture was allowed to react for 45 minutes under stirring and nitrogen at a bath temperature of 85°C. The NCO content was measured. If the NCO was close to 0%, the mixture was left stirring for an additional 20 minutes under vacuum at a bath temperature of 85°C.

[0096] Description of the manufacturing process of the toughening agent of the present invention Comp. A(X) (poly THF) was placed in a laboratory reactor and heated to 130° C. under stirring and vacuum. When this temperature was reached, the mixture was cooled to 70° C. with stirring. The vacuum was released and Comp. B (HDI) was added. The mixture was mixed under nitrogen for 2 minutes, after which Comp. D (TIB KAT 718) was added. The mixture was allowed to react for 45 minutes under stirring and nitrogen with a bath temperature of 85° C. The NCO content was measured (Table 2 "NCO 1 st RS). If the NCO content was close to the expected value, the mixture was cooled to 60° C. under nitrogen with stirring. When the material temperature reached 60° C., Comp.G (CPEE) was added. The mixture was allowed to react for 45 minutes under stirring and nitrogen at a bath temperature of 85° C. The NCO content was checked. If the NCO content was close to 0%, the mixture was stirred for an additional 20 minutes under vacuum at a bath temperature of 85° C.

[0097] glue Component A (resin component) Component A (resin component) of the adhesive was formulated by mixing the ingredients listed in Table 3. The formulation was the same with respect to the epoxy resin, adhesion promoter, and filler. The only difference was the toughener used. The toughener in comparative resin 1 is diluted during synthesis with liquid epoxy resin to improve processability. Resins 2 and 3 of the invention contain a toughener with the capping group CPEE of the invention. In resin 2 the toughener is made only from PTHF as the polyol, while in resin 3 the toughener is obtained from a mixture of PTHF and polybutadiene diol.

[0098] [Table 3]

[0099] Component B (hardener component) Table 4 shows the hardener component ingredients used to cure three different components A with a 2:1 A:B B ratio applied from 2:1 side-by-side cartridges. The epoxy resin component was loaded in the high volume side and the amine hardener was loaded in the low volume cartridge. The static mixer used was a Sulzer Quadro mixer equipped with 24 mixing elements.

[0100] [Table 4]

[0101] Test Method Rheology Rotational viscosity / yield stress: Bohlin CS-50 rheometer, C / P20, rise / fall 0.1~20s -1 ;45°C;Evaluated using Casson model.

[0102] thermal analysis Dynamic Mechanical Analysis (DMA): Glass Transition Temperature T g was determined by DMA measurement and defined as the maximum value of tan δ. Test method: Temperature range: 40°C to +250°C; Frequency: 1Hz; Heating rate: 3°C / min.

[0103] Mechanical testing The lap shear strength was determined according to DIN EN1465-2009-07: DC04ZE (steel), thickness 0.7 mm, degreased with heptane, bond area 10 x 25 mm, adhesive layer thickness 0.2 mm. Curing took place at room temperature for 7 days.

[0104] Impact peel strength was measured according to BS EN ISO 11343:2003: bond area 20x30mm, adhesive layer thickness 0.2mm, steel used: DX56Z / DC04ZE (steel), thickness 0.7mm, degreased with heptane, measured at 23°C, bond area 20x30mm, adhesive layer thickness 0.2mm. Curing was at room temperature for 7 days.

[0105] Sample preparation Metal strips of the given steel grade were cleaned with heptane in an ultrasonic bath and regreased by dip coating in a solution of heptane / Anticorit PL 3802-39S (9 / 1).

[0106] Tensile test (DIN ISO EN-527-1:2012-06) Plates of the cured adhesive were prepared with a thickness of 2 mm and cured at room temperature for 7 days. Dog-bone shaped test specimens were cut out of the plates. The dimensions were in accordance with DIN ISO EN-527-1 and therefore the tests were carried out using a Zwick tensile testing machine.

[0107] T-peel strength (ISO 11339:2010) The T-peel strength was measured on 0.7 mm thick DC04ZE steel from Thyssen Krupp. To adjust the adhesive layer to 0.2 mm, 0.2 mm thick glass beads were used as spacers between both strips. The test was carried out according to DIN 53282. The specimens for the T-peel test have the test geometry of DIN 53282 (overlap 30 mm, width 20 mm). Metal clips were used to hold the two strips together during the baking cycle. The adhesive is cured at room temperature for 7 days.

[0108] Impact peel test specimen (ISO 11343:2003) The adhesive composition was applied to a 0.7 mm steel strip of DC04ZE. To adjust the adhesive layer to 0.2 mm, a 0.2 mm thick PTFE foil and a metal wire (0.2 mm thick) were used as spacers between both strips. The specimens for the impact peel test have the geometry of the ISO 11343 test (30 mm overlap, 20 mm width). Metal clips were used to hold the two strips together during curing. Curing was for 7 days at room temperature. All coupon / adhesive assemblies were cured for 30 minutes in an oven at 180 °C. For the impact peel test, the specimens were subjected to an impact load of 90 J with a falling weight speed of 2 m / s. The impact peel strength was measured at the average impact load at the plateau using a Zwick-Roell impact tester.

[0109] Table 5 summarizes the test results of the examples of the present invention and the comparative examples. In Comparative Example 1, Comp. Resin 1 was used as component A (resin component), and in Examples 2 and 3 of the present invention, Comp. Resin 1 was used as component A (resin component). Resin 2 and Resin 3 of the invention were used, respectively.

[0110] [Table 5]

[0111] The data in Table 5 show that the adhesives of the invention, in which the toughener includes a CPEE capping group, outperform the comparative adhesives in which the toughener is capped with a phenol in all measured mechanical properties.

[0112] Comparative Example 1 differs only in the end-capping group of the toughening agent and is compared directly with Inventive Example 2. The Inventive formulation exhibits significantly higher impact peel resistance and significantly higher T-peel resistance than the reference. The ultimate tensile strength is also 24% higher for Inventive Example 2.

[0113] In Example 3 of the present invention, the incorporation of polybutadiene diol into the toughener backbone in addition to poly THF results in even better performance in terms of impact resistance (+50% vs. Comparative Example 1), T-peel resistance (+80% vs. Comparative Example 1), as well as tensile strength (+43%) and e-modulus (+88%).

[0114] From this, it can be concluded that the use of blocking groups that do not undergo deblocking, but rather react directly with amines during adhesive curing, and react with amines to bond to the matrix, simultaneously improves toughness and hardness. The present invention includes the following aspects. Section 1. 1. A two-part epoxy adhesive composition comprising: Component A: ai) at least one epoxy resin; aii) reacting at least one polyol, such as a poly(alkylene oxide) diol and optionally a poly(butadiene) diol, with a polyisocyanate in the presence of a polyurethane catalyst, optionally followed by chain extension with a diphenol, to produce a molecule of formula I: [ka] (In the formula, R 1 and R 2 are independently hydrogen and C 1 ~C 6 alkyl, n is an integer from 1 to 2, R 3 is C 1 ~C 6 (It is alkyl) a reactive toughener prepared by endcapping with; Component B: bi) one or more polyamines; bii) optionally one or more latent epoxy hardeners; biii) one or more epoxy curing catalysts; 1. A two-part epoxy adhesive composition comprising: Section 2. Item 2. The composition according to item 1, wherein the at least one epoxy resin comprises an epoxy resin selected from those having an epoxy equivalent in the range of about 170 to 195 g / mol. Section 3. Item 3. The composition according to item 1 or 2, wherein the at least one epoxy resin comprises a liquid reaction product of epichlorohydrin and bisphenol A having an epoxide equivalent weight (measured according to ASTM D-1652) of 182 to 192 g / eq. Section 4. Item 4. The composition according to item 1, 2, or 3, wherein the at least one epoxy resin comprises an epoxy having an epoxide percentage (measured according to ASTM D-1652) of 22.4 to 23.6% and an epoxide group content (measured according to ASTM D-1652) of 5200 to 5500 mmol / kg. Section 5. The composition according to any one of items 1 to 4, wherein the at least one epoxy resin comprises an epoxy having a viscosity of 4000 to 14000 mPas at 25 ° C. (measured according to ASTM D-445). Section 6. The at least one epoxy resin is used in an amount of 50 to 80% by weight, more preferably 55 to 75% by weight, and particularly preferably 60 to 72% by weight, based on the total weight of component A of the adhesive. The composition according to any one of items 1 to 5. Section 7. R 1 and R 2 But H and C 1 ~C 4 The composition according to any one of items 1 to 6, wherein each of the alkyl groups is independently selected from alkyl. Section 8. R 1 and R 2 But H and C 1 ~C 2 The composition according to any one of items 1 to 7, wherein each of the alkyl groups is independently selected from alkyl. Section 9. R 1 and R 2 The composition according to any one of items 1 to 8, wherein is H. Section 10. R 3 but 1 ~C 4 Item 10. The composition according to any one of items 1 to 9, wherein the alkyl is alkyl. Section 11. R 3 C 1 ~C 2 Item 11. The composition according to any one of items 1 to 10, wherein the alkyl is alkyl. Section 12. R 3 Item 12. The composition according to any one of items 1 to 11, wherein is ethyl. Section 13. Item 13. The composition according to any one of items 1 to 12, wherein n is 1. Section 14. Item 14. The composition according to any one of items 1 to 13, wherein the end-capping molecule is ethyl-2-oxocyclopentanecarboxylate. Section 15. The poly(alkylene oxide) diol used in the toughening agent is poly(C 2 ~C 6 Item 15. The composition according to any one of items 1 to 14, wherein the diol is selected from alkylene oxide diols. Section 16. Item 16. The composition according to any one of items 1 to 15, wherein the poly(alkylene oxide) diol used in the toughening agent is selected from poly(tetramethylene oxide) diol ("PTMEG"), poly(trimethylene oxide) diol ("PO3G"), and mixtures thereof. Section 17. Item 17. The composition according to any one of items 1 to 16, wherein the poly(alkylene oxide) diol has a molecular weight in the range of 1,000 to 2,500 Da. Section 18. Item 18. The composition according to any one of items 1 to 17, wherein the poly(alkylene oxide) diol has a molecular weight of 1,000 to 2,000 Da, or a mixture thereof is used. Section 19. Item 19. The composition according to any one of items 1 to 18, wherein the poly(alkylene oxide) diol is PTMEG having a molecular weight in the range of 1,000 to 2,500 Da. Section 20. 20. The composition according to any one of claims 1 to 19, wherein poly(butadiene) diol ("PBD") is used as the toughening agent. Section 21. Item 21. The composition according to item 20, wherein the PBD has a molecular weight in the range of 2,000 to 3,500 Da. Section 22. Item 21. The composition according to item 20, wherein the PBD has a molecular weight of 2,800 Da. Section 23. Item 23. The composition according to any one of items 1 to 22, wherein the at least one poly(alkylene oxide) diol is PTMEG and PBD is included in the toughening agent backbone. Section 24. 24. The composition according to any one of items 1 to 23, wherein the at least one polyisocyanate used in the toughening agent is an aliphatic diisocyanate. Section 25. 25. The composition according to any one of claims 1 to 24, wherein the at least one polyisocyanate is selected from 1,6-hexamethylene diisocyanate ("HMDI"), isophorone diisocyanate (IPDI), and mixtures thereof. Section 26. 26. The composition according to any one of claims 1 to 25, wherein the at least one polyisocyanate is hexamethylene diisocyanate ("HMDI"). Section 27. 27. The composition according to any one of items 1 to 26, wherein the chain extension is carried out using a diphenol. Section 28. Item 28. The composition according to item 27, wherein the diphenol is O,O'-diallyl bisphenol A. Section 29. 29. The composition according to any one of claims 1 to 28, wherein the polyurethane catalyst is selected from dibutyltin dilaurate ("DBTL") and a metal carboxylate, such as a bismuth carboxylate and / or a zinc carboxylate. Section 30. 30. The composition according to any one of items 1 to 29, wherein the polyurethane catalyst is used in an amount of 0.01 to 0.5 wt %, more preferably 0.1 wt %, based on the total weight of the toughening agent. Section 31. Item 31. The composition according to any one of items 1 to 30, wherein the polyurethane catalyst is a mixture of bismuth carboxylate and zinc carboxylate. Section 32. Item 32. The composition according to any one of items 1 to 31, wherein the toughening agent comprises 40 to 90% by weight of poly(alkylene oxide) diol based on the total weight of the toughening agent. Section 33. Item 33. The composition according to any one of items 1 to 32, wherein the toughening agent comprises 45 to 85 wt. % of a poly(alkylene oxide) diol based on the total weight of the toughening agent. Section 34. Item 34. The composition according to any one of items 1 to 33, wherein the toughening agent comprises 50 to 85 wt. % of a poly(alkylene oxide) diol based on the total weight of the toughening agent. Section 35. Item 35. The composition according to any one of items 1 to 34, wherein the toughening agent comprises 50 to 85 wt. % PTMEG, 7 to 20 wt. % HDI, and 5 to 15 wt. % end-capping group, particularly CPEE, based on the total weight of the toughening agent. Section 36. Item 36. The composition according to any one of items 1 to 35, wherein the toughening agent comprises 50 to 85 wt. % PTMEG, 8 to 20 wt. % PBD, 7 to 20 wt. % HDI, and 5 to 15 wt. % end-capping group, particularly CPEE, based on the total weight of the toughening agent. Section 37. 37. The composition according to any one of items 1 to 36, wherein the at least one polyamine in component B has an amine functionality of 2 or more. Section 38. Item 38. The composition according to any one of items 1 to 37, wherein the at least one polyamine in component B comprises at least one molecule having an amine functionality of 10 or more in combination with one or more diamines. Section 39. Item 39. The composition according to any one of items 1 to 38, wherein the at least one polyamine in component B comprises at least one polyetheramine. Section 40. Item 40. The composition according to any one of items 1 to 39, wherein the at least one polyamine in component B comprises a primary amine group and a secondary amine group. Section 41. Item 41. The composition according to any one of items 1 to 40, wherein the at least one polyamine in component B comprises a primary amine group. Section 42. The at least one polyamine in component B is [Table X] Item 42. The composition according to any one of items 1 to 41, selected from the group consisting of: Section 43. 43. The composition according to any one of the preceding claims, wherein the at least one polyamine in component B comprises a mixture of Lupasol P, Jeffamine T-403, Jeffamine D-400, Jeffamine D-2000, and 4,7,10-trioxatridecane-1,13-diamine. Section 44. Item 44. The composition according to any one of items 1 to 43, wherein the at least one polyamine in component B comprises a mixture of Lupasol P, Jeffamine T-403, TETA, and 4,7,10-trioxatridecane-1,13-diamine. Section 45. Item 45. The composition according to any one of items 1 to 44, wherein the latent epoxy curing agent is selected from boron trichloride / amine and boron trifluoride / amine complexes, melamine, diallylmelamine, guanamines such as dicyandiamide, methylguanidine, dimethylguanidine, trimethylguanidine, tetramethylguanidine, methylisobiguanidine, dimethylisobiguanidine, tetramethylisobiguanidine, heptamethylisobiguanidine, hexamethylisobiguanidine, acetoguanamine and benzoguanamine, aminotriazoles such as 3-amino-1,2,4-triazole, hydrazides such as adipic acid dihydrazide, stearic acid dihydrazide, isophthalic acid dihydrazide, semicarbazide, cyanoacetamide, and aromatic polyamines such as aminodiphenylsulfone. Section 46. Item 46. The composition according to any one of items 1 to 45, wherein the latent epoxy curing agent is dicyandiamide. Section 47. The epoxy curing catalyst is p-chlorophenyl-N,N-dimethylurea (monuron), 3-phenyl-1,1-dimethylurea (fenuron), 3,4-dichlorophenyl-N,N-dimethylurea (diuron), N-(3-chloro-4-methylphenyl)-N',N'-dimethylurea 25 (chlortoluron), tert-acryl- or alkylenediamine (benzyldimethylamine, etc.), 2,4,6-tris(dimethylaminomethyl)phenol, piperidine or a derivative thereof, C1 ~C 12 Item 47. The composition according to any one of items 1 to 46, selected from alkylene imidazoles or N-arylimidazoles (such as 2-ethyl-2-methylimidazole), or N-butylimidazole and 6-caprolactam, 2,4,6-tris(dimethylaminomethyl)phenol incorporated in a poly(p-vinylphenol) matrix (such as those described in European Patent No. 0197892), or 2,4,6-tris(dimethylaminomethyl)phenol incorporated in a novolac resin (such as those described in U.S. Patent No. 4,701,378). Section 48. Item 48. The composition according to any one of items 1 to 47, wherein the epoxy curing catalyst is tris-2,4,6-tris(dimethylaminomethyl)phenol. Section 49. Item 49. The composition according to any one of items 1 to 48, wherein the epoxy curing catalyst is present in an amount of 1 to 20% by weight, more preferably 8 to 16% by weight, and particularly preferably 10 to 14% by weight, based on the total weight of component B. Section 50. Item 50. The composition according to any one of items 1 to 49, wherein the epoxy curing catalyst is 2,4,6-tris(dimethylaminomethyl)phenol incorporated in a poly(p-vinylphenol) polymer matrix and is used in an amount of 10 to 14% by weight, more preferably 12% by weight, based on the total weight of component B. Section 51. 1. A method for bonding two substrates, comprising: 1. Preparing a two-part epoxy adhesive composition according to any one of items 1 to 50; 2. Mixing components A and B to produce a mixture; 3. applying the mixture to a first substrate and / or a second substrate; 4. placing the substrates such that the substrate surfaces are in adhesive contact to sandwich a layer of the mixture therebetween; and 5. Curing the mixture; The method includes: Section 52. 52. The method of claim 51, wherein the first and second substrates are metals independently selected from steel and aluminum. Section 53. 53. The method according to claim 51 or 52, wherein the mixing ratio of component A to component B is 1:1 or 2:1. Section 54. 54. The method of claim 51, 52, or 53, wherein curing is carried out at a temperature below 40° C.

Claims

1. 1. A two-part epoxy adhesive composition comprising: Component A comprising: ai) at least one epoxy resin; and aii) reacting at least one polyol selected from poly(alkylene oxide) diols and poly(butadiene) diols with a polyisocyanate in the presence of a polyurethane catalyst, optionally followed by chain extension with a diphenol, to produce a molecule of formula I: 【Chemistry 1】 (In the formula, R １ and R ２ are independently hydrogen and C １ ~C ６ alkyl, n is an integer from 1 to 2, R ３ is C １ ~C ６ is alkyl) a reactive toughener prepared by endcapping with Component B comprising: bi) one or more polyamines; bii) optionally one or more latent epoxy hardeners; and biii) one or more epoxy curing catalysts; 1. A two-part epoxy adhesive composition comprising:

2. 2. The composition of claim 1, wherein the at least one epoxy resin comprises an epoxy having an epoxide percent fraction (measured according to ASTM D-1652) of 22.4 to 23.6%, an epoxide group content (measured according to ASTM D-1652) of 5200 to 5500 mmol / kg.

3. The composition of claim 1, wherein the at least one epoxy resin is used in an amount of 50 to 80% by weight, based on the total weight of component A of the adhesive composition.

4. R １ and R ２ But H and C １ ~C ４ The composition of claim 1 , wherein the alkyl is independently selected from alkyl.

5. R １ and R ２ But H and C １ ~C ２ The composition of claim 4, wherein the alkyl is independently selected from alkyl.

6. R １ and R ２ The composition of claim 5 , wherein is H.

7. R ３ but １ ~C ４ The composition of claim 1 wherein the alkyl group is an alkyl group.

8. R ３ C １ ~C ２ The composition of claim 7, wherein the alkyl group is an alkyl group.

9. R ３ The composition according to claim 8, wherein R is ethyl.

10. The composition of claim 1 , wherein n is 1.

11. The composition of claim 1, wherein the end-capping molecule is ethyl-2-oxocyclopentanecarboxylate.

12. The poly(alkylene oxide) diol used in the toughening agent is poly(C ２ ~C ６ 2. The composition of claim 1, wherein the diol is selected from the group consisting of alkylene oxide diols.

13. 13. The composition of claim 12, wherein the poly(alkylene oxide) diol used in the toughening agent is selected from poly(tetramethylene oxide) diol ("PTMEG"), poly(trimethylene oxide) diol ("PO3G"), and mixtures thereof.

14. The composition of claim 1 , wherein poly(butadiene) diol ("PBD") is used as the toughening agent.

15. The composition of claim 1, wherein the polyisocyanate is selected from 1,6-hexamethylene diisocyanate ("HMDI"), isophorone diisocyanate (IPDI), and mixtures thereof.

16. 2. The composition of claim 1, wherein the polyurethane catalyst is selected from dibutyltin dilaurate ("DBTL") and metal carboxylates.

17. 10. The composition of claim 1, wherein the polyurethane catalyst is a mixture of bismuth and zinc carboxylates.

18. The composition of claim 1 , wherein the at least one polyamine in component B has an amine functionality of 2 or greater.

19. 10. The composition of claim 1, wherein the at least one polyamine in component B comprises at least one molecule having an amine functionality of 10 or greater in combination with one or more diamines.

20. 2. The composition of claim 1, wherein the latent epoxy hardener is selected from boron trichloride / amine and boron trifluoride / amine complexes, melamine, diallylmelamine, guanamine, methylguanidine, dimethylguanidine, trimethylguanidine, tetramethylguanidine, methylisobiguanidine, dimethylisobiguanidine, tetramethylisobiguanidine, heptamethylisobiguanidine, hexamethylisobiguanidine, acetoguanamine, benzoguanamine, aminotriazole, hydrazide, stearic dihydrazide, isophthalic dihydrazide, semicarbazide, cyanoacetamide, and aromatic polyamines.

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