Epoxy adhesive composition and method of use

Abstract

To provide an epoxy adhesive composition that exhibits an excellent balance of fast fixation, curing speed, desirable mechanical performance, durability, and excellent oil adsorption once cured.SOLUTION: An epoxy adhesive composition comprises in admixture: A) one or more epoxy resins which are liquid at 23°C; B) one or more reactive urethane group- and / or urea group-containing polymers having capped isocyanate; C) an epoxy curing catalyst; D) dicyandiamide; and E) a hardener. The epoxy adhesive composition has a lap shear strength according to DIN EN 1465:2009-07 equal to or greater than 0.2 MPa after induction curing for 1 minute at 120°C, and a lap shear strength greater than 15 MPa after curing for 25 minutes at 165°C, both measured on the combination of 0.8 mm-thick hot dip galvanized steel DX56D and 0.8 mm-thick electrogalvanized steel DC 04 (DIN EN 10346:2015-10).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to epoxy adhesive compositions, methods of making and using said compositions. The epoxy adhesive composition comprises an epoxy resin and a capped isocyanate. Reactive urethane group and / or urea group-containing polymer, epoxy curing catalyst, dicyandiamide and a curing agent. The epoxy adhesive composition is capable of both 1K and 2K technology in one system. and combines the benefits of fast setting, cure speed, desirable mechanical performance, durability and hardening properties. It exhibits an excellent balance of excellent oil absorption after application. [Background technology]

[0002] In the automotive industry, 1K structural epoxy adhesives are used to join metals in auto body shops. These are cured in an e-coat oven at high temperature, e.g. 180°C for 30 minutes. Before oven curing, the adhesive has little or no sufficient mechanical strength to secure the parts together. If part fastening is desired, the adhesive is used in conjunction with an additional fastening method, typically a spongy adhesive. This must be combined with mechanical fastening such as hot welding or rivets.

[0003] In areas such as door and hood attachments where the part has a flange, If the adhesive does not have sufficient mechanical strength before e-coating, the parts may move in the oven and cause dimensional distortion. To prevent this, some OEMs offer products that develop strength at room temperature. Use 2K structural adhesive or up to a strength level of more than 0.2 MPa, already at 80°C It can be pre-cured to handling strength at low temperatures such as ∼120°C.

[0004] Although this rapid cure of 2K structural epoxy adhesives is advantageous for dimensional stability, This is a drawback in terms of oil absorption. 2K adhesives tend to be absorbed immediately after application (e.g., 5 minutes to 1 hour). Only if the temperature treatment is applied to the net The workpiece formation is much more advanced and the oil can diffuse and dissolve in the epoxy adhesive at high temperatures. , after artificial aging or even already in the early stages, an inefficient failure mode results.

[0005] The advantages of 1K structural epoxy adhesives are excellent oil absorption, excellent mechanical performance and durability. and is superior to 2K structural epoxy adhesives. Summary of the Invention [Problem to be solved by the invention]

[0006] Rapid setting, speed of cure, desirable mechanical properties, durability and excellent oil absorption after cure. An epoxy that combines the benefits of both 1K and 2K technology in one system, demonstrating an excellent balance It would be desirable to have an adhesive composition. [Means for solving the problem]

[0007] In one embodiment, the present invention provides a method for preparing a mixture of: A) one or more compounds that are liquid at 23°C; B) a capped epoxy resin, preferably a diglycidyl ether of a bisphenol; Preferably, the isocyanate has a monophenol or polyphenol cap. C) one or more reactive urethane group and / or urea group-containing polymers, and an epoxy curing catalyst containing a catalyst, preferably a urea compound; D) dicyandiamide; and E) a curing agent. a methylating agent, preferably a primary amine group, a secondary amine group, a mercapto group and / or a phenol and a curing agent containing one or more of the following groups: After induction hardening, the seal is rated to 0.2 MPa or more according to DIN EN 1465:2009-07 and lap shear strength of over 15 MPa after curing at 165°C for 25 minutes. The lap shear strength was measured using hot-dip galvanized steel DX56D and 0.8 mm thick steel. Measured on 0.8mm thick electrogalvanized steel DC04 (DIN E N 10346:2015-10), an epoxy adhesive composition.

[0008] In another embodiment, the present invention provides a composition comprising 0 to 0.7% by weight of the epoxy adhesive composition. The adhesive disclosed herein above, optionally comprising 5% by weight of glass microspheres. It is a composition.

[0009] Another embodiment of the present invention is a composition comprising: i) a first component comprising: A) one or more components that are liquid at 23°C; the epoxy resin and B) one or more reactive epoxy resins having capped isocyanate groups. C) a ethane group and / or urea group-containing polymer; C) an epoxy curing catalyst; and D) dicyandiaceous ii) a first component comprising a hydroxybenzoate and a hydroxybenzoate; and ii) a second component comprising E) a curing agent. By mixing, an epoxy adhesive composition as disclosed hereinabove is formed. wherein the epoxy adhesive composition has a viscosity of 0.2 MP after induction curing at 120°C for 1 minute. Lap shear strength according to DIN EN 1465:2009-07 of at least a and at 165°C and after 25 minutes of curing, a lap shear strength of greater than 15 MPa, said lap shear strength being , both 0.8mm thick hot dip galvanized steel DX56D and 0.8mm thick electrolytic zinc Measured in combination with galvanized steel DC04 (DIN EN 10346:2015 -10), the method.

[0010] Another embodiment of the present invention is a method for manufacturing a first epoxy adhesive composition and a second epoxy adhesive composition. A method for applying a substance to a substrate, comprising: 1) adding, to a mixture, A) a solution of a substance that is liquid at 23°C; B) one or more epoxy resins and one or more reactive copolymers having capped isocyanates C) a polymer containing a urethane group and / or a urea group, C) an epoxy curing catalyst, and D) dicyandiamide. 1) applying to a substrate a first epoxy adhesive composition comprising an amide; and A) one or more epoxy resins that are liquid at 23°C; and B) a capped isocyanate. C) one or more reactive urethane and / or urea group-containing polymers having an ester; A second epoxy adhesive composition comprising: D) an alkoxy curing catalyst; E) dicyandiamide; and F) a curing agent. and applying the composition to a substrate. Preferably, steps 1 and 2 are repeated two or more times. More preferably, components A), B), C) and D) of the first epoxy adhesive composition are The components A), B), C) and D) of the epoxy adhesive composition of No. 2 are the same as those of the epoxy adhesive composition of No. 2, and the method comprises the steps of Between steps 1 and 2, a curing agent E) is mixed into the first epoxy adhesive composition to form the second The method further comprises the step of producing the epoxy adhesive composition according to Step 1 and Step 2. The epoxy adhesive composition has a DIN tensile strength of over 15 MPa after curing at 165°C for 25 minutes. Both have lap shear strength according to EN 1465:2009-07 and The thickness is 0.8mm hot dip galvanized steel DX56D and 0.8mm thick electroplated steel. Measured on galvanized steel DC04 (DIN EN 10346:20 15-10). DETAILED DESCRIPTION OF THE INVENTION

[0011] The epoxy adhesive composition of the present invention contains at least one epoxy resin (component A). In one embodiment, the epoxy resin is not rubber modified and / or phosphorus modified. "Not modified with rubber" means that the epoxy resin is not modified with any of the following before curing: This means that the rubber is not chemically bonded to the polymer.

[0012] "Not modified with phosphorus" means that the epoxy resin is not modified with phosphorus, Polyphosphoric acid, phosphate salts, polyphosphate salts, phosphate esters, or polyphosphate esters This means that the teru is not reacting.

[0013] If only a single epoxy resin is present, it is liquid at 23°C. If epoxy resins are present, the individual epoxy resins in the mixture will themselves solidify at 23°C. Although the mixture may be liquid at 23°C, the mixture is liquid at 23°C.

[0014] Column 2, 66 of U.S. Pat. No. 4,734,332, which is incorporated herein by reference. A wide range of epoxy resins can be used, including those listed in columns 4-24. The epoxy resin has an average of at least 1.8 units per molecule, preferably at least It should have 2.0 epoxide groups. The epoxy equivalent weight is, for example, 75 to 350. It may be 140 to 250 and / or 150 to 225. When a mixture of epoxy resins is present, In this case, the mixture has an average epoxy functionality of at least 1.8, preferably at least 2.0, and and the epoxy equivalent weight as in the preceding sentence, more preferably Each epoxy resin has such an epoxy functionality and epoxy equivalent weight.

[0015] Suitable epoxy resins include resorcinol, catechol, hydroquinone, biphenyl, phenol, bisphenol A, bisphenol AP (1,1-bis(4-hydroxyphenyl) (phenyl)-1-phenylethane), bisphenol F, bisphenol K and tetramethyl Diglycidyl ethers of polyphenolic compounds such as biphenols; C 2~24 Alkire diglycidyl ethers of aliphatic glycols, such as diglycidyl ether of ethylene glycol; Phenol-formaldehyde novolac resin (epoxy novolac resin), alkyl group Phenol-formaldehyde resin, phenol-hydroxybenzaldehyde resin, Cresol-hydroxybenzaldehyde resin, dicyclopentadiene-phenol resin and polyglycidyl ethers of dicyclopentadiene-substituted phenolic resins; and Any combination of any two or more of these may be mentioned.

[0016] Suitable epoxy resins include DER330, DER331, DE R.332, DER383, DER661 and DER662 resin names Bisphenol A, such as that sold by Olin Corporation under the name Examples of suitable diglycidyl ethers include diglycidyl ethers of glycerol A resin.

[0017] Epoxy novolac resins may be used. Such resins include DEN354, Olin Co as DEN431, DEN438 and DEN439 It is commercially available from Ref.

[0018] Other suitable epoxy resins are cycloaliphatic epoxides. Cycloaliphatic epoxides include those listed below. Structure I: [ka] (wherein R is an aliphatic, alicyclic and / or aromatic group, n is 1 to 10, preferably is a number between 2 and 4) When n is 1, the alicyclic epoxide is a monoepoxide. When n is 2 or more, a diepoxide or polyepoxide is formed. Mixtures of monoepoxides, diepoxides and / or polyepoxides can be used. No. 3,686,359, which is incorporated herein by reference. Cycloaliphatic epoxy resins such as those listed above can be used in the present invention. Cycloaliphatic resins of particular interest are The epoxy resin is (3,4-epoxycyclohexyl-methyl)-3,4-epoxy-cyclohexyl Cyclohexanecarboxylate, bis-(3,4-epoxycyclohexyl) adipate , vinylcyclohexene monoxide and mixtures thereof.

[0019] Other suitable epoxy resins include those described in U.S. Pat. No. 5,112,932. In addition, DER592 and and those commercially available as DER6508 (Dow Chemical). High performance epoxy-isocyanate copolymers can be used.

[0020] In some embodiments, the epoxy resin is a first epoxy resin having an epoxy equivalent weight of up to 225. Diglycidyl ether of bisphenol and epoxy equivalent weight of more than 225 to 750 The mixture contains a diglycidyl ether of a second bisphenol. The mixture is liquid at that temperature. The first diglycidyl bisphenol ether is a liquid at 23°C. and the second diglycidyl bisphenol ether may itself be a solid at 23°C. Each of these is a diglycidyl ether of bisphenol A or bisphenol F. These may be partially chain extended to obtain epoxy equivalent weight as shown. obtain.

[0021] Component B) is a copolymer of one or more reactive urethane groups having a number average molecular weight of up to 35,000. and / or urea group-containing polymers, at least those having a weight of at least 1000 atomic mass units Each of the polyether or diene rubber segments and the capped isocyanate group Useful such materials are described, for example, in U.S. Pat. Nos. 5,202,390 and 5,202,390. No. 5,278,257, WO 2005 / 118734 pamphlet, Brochure No. 2007 / 003650, Brochure No. 2012 / 091842, U.S. Patent Application Publication Nos. 2005 / 0070634 and 2005 / 0209401 No. 2006 / 0276601, European Patent Application Publication No. A-03086 Specification No. 64, Specification No. 1498441A, Specification No. A-1728825, Specification No. Specification No. A-1896517, Specification No. A-1916269, Specification No. A-191627 0, A-1916272 and A-1916285 It is listed.

[0022] Other toughening agents, component (b), useful in the present invention include, for example, bisphenol A. Chain extended and capped with diisopropylamine - hexamethylene diisocyanate Derived from polytetramethylene ether glycol (PTMEG) PU-toughening agents may be included. For example, toughening agents useful in the present invention include The Dow Chemical Company, product names "RAM DIPA" and "Flexib Available as "ILIZER DY 965" and "INT LMB6633", see references. The present invention is described in International Publication No. WO 2016108958A1, which is incorporated herein by reference. Examples of the strengthening agents include those listed in the patent application.

[0023] The component B) material is conveniently an isocyanate-terminated polyether and / or diene and capping the isocyanate groups with phenol or polyphenol. The isocyanate-terminated polyether and / or diene rubber is preferably Conveniently, a hydroxyl-terminated polyether or an amine-terminated polyether, a hydroxyl-terminated polyether, a an excess of polyisocyanate, an amine-terminated diene rubber, or a mixture of both; reacting with esters to produce adducts with urethane or urea groups and terminal isocyanate groups. Optionally, isocyanate-terminated polyether and / or The diene rubber is capped by a capping reaction, or before or simultaneously with the capping reaction. can be chain extended and / or branched.

[0024] The isocyanate-terminated polyether or isocyanate-terminated diene polymer is an aromatic The polyisocyanates used in preparing this material may have aliphatic or aliphatic isocyanate groups. The isocyanate preferably has at least two isocyanate groups per molecule and This is because aromatic polyisocyanates, such as toluenediamines, have molecular weights of up to 1 / mol. amine or 2,4'- and / or 4,4'-diphenylmethanediamine or e.g. isophorone 1,6-Hexamethylene Diisocyanate, Hydrogenated Toluene Diisocyanate Cyanate, hydrogenated methylene diphenyl isocyanate (H 12 Aliphatic polyols such as MDI It may be a reisocyanate.

[0025] Hydroxyl- or amine-terminated polyethers are prepared by dissolving tetrahydrofuran (tetramethyl 1,2-butylene oxide, 2,3-butylene oxide, 1,2-propanol It may be a polymer or copolymer of one or more of pyrene oxide and ethylene oxide, tetrahydrofuran, 1,2-butylene oxide, 2,3-butylene oxide and 1,2- of propylene oxide, at least 70% by weight based on the total weight of the polymer or copolymer % polymer or copolymer based on the total weight of the polymer or copolymer is preferred. Polymers with at least 80% by weight of tetrahydrofuran are particularly preferred. preferably has 2 to 3, more preferably 2 hydroxyls per molecule and / or The starting polyether preferably has a viscosity of 900 to 800 MPa. 0, more preferably 1500 to 6000 or 1500 to 4000 .

[0026] The hydroxyl-terminated or amine-terminated diene polymer is preferably It is preferable that the glass transition temperature is -20°C or less, and more preferably -40°C or less. The ene polymers are liquid homopolymers or copolymers of conjugated dienes, especially diene / nitrile polymers. The conjugated diene is preferably butadiene or isoprene, especially Butadiene is preferred. The preferred nitrile monomer is acrylonitrile. The preferred copolymer is butadiene-acrylonitrile copolymer. , in the aggregate, up to 30% by weight of polymerized unsaturated nitrile monomer, preferably about 26 Contains up to 50% by weight of polymerized nitrile monomers. Hydroxyl-terminated or amine-terminated diene The polymer preferably has 1.8 to 4, more preferably 2 to 3, hydrophilic groups per molecule. The starting diene polymer preferably has hydroxyl and / or primary or secondary amino groups. is 900 to 8000, more preferably 1500 to 6000, and even more preferably 200 It has a number average molecular weight of 0 to 3,000.

[0027] The isocyanate-terminated polymer is conveniently prepared from a starting polyether or diene rubber. of polyisocyanate per equivalent of hydroxyl and / or primary or secondary amino groups At least 1.5 equivalents, preferably 1.8 to 2.5 equivalents or 1.9 to 2.2 equivalents of acetone the polyisocyanate and a hydroxyl- or amine-terminated polyether in the ratio and / or prepared by reaction with hydroxyl-terminated or amine-terminated diene rubbers.

[0028] The reaction to produce the isocyanate-terminated polymer optionally comprises the addition of an isocyanate a catalyst for reacting the hydroxyl groups with the isocyanate-reactive groups of the polyether or diene polymer The starting polyether and / or diene rubber is combined with a polyisocyanate in the presence of a catalyst. The reaction can be carried out by combining the isocyanate-containing Continue stirring until the amount of the starting polyether or diene polymer decreases to a constant or target value, or until the amount of the starting polyether or diene polymer decreases to a constant or target value. The reaction is continued until the alkyl and / or hydroxyl groups are consumed.

[0029] Optionally, a diisocyanate between the starting polyether or diene polymer and the polyisocyanate Branching can be achieved by adding a branching agent to the reaction or in a subsequent step. In this respect, the branching agent has a molecular weight of up to 599, preferably 50 to 500, and and a poly(ethylene glycol) having at least three hydroxyl, primary amino and / or secondary amino groups. If used at all, the branching agent is generally a branching amine or polyamine compound. 10% or less of the combined weight of the agent and the starting polyether or diene polymer, preferably Preferably, the branching agent comprises no more than 5%, and even more preferably no more than 2%. trimethylolpropane, glycerin, trimethylolethane, ethylene glycol Coal, diethylene glycol, propylene glycol, dipropylene glycol, Sucrose, sorbitol, pentaerythritol, triethanolamine, diethanolamine and those alkoxy groups having a number average molecular weight of up to 599, especially up to 500. Examples include silates.

[0030] Optionally, i) isocyanate-terminated polyether and / or diene polymers or ii) incorporating a chain extender into the reaction to form the capping step. In between, isocyanate-terminated polyether and / or diene polymers are reacted with chain extenders. The chain extender can be used in an amount of up to 749, preferably 5 Polyol or polyamine compounds having a molecular weight of 0 to 500 and two per molecule Examples of suitable chain extenders include those containing hydroxyl, primary amino and / or secondary amino groups. For example, aliphatic diols such as ethylene glycol, diethylene glycol, triethylene glycol, Glycol, propylene glycol, dipropylene glycol, tripropylene glycol 1,4-butanediol, 1,6-hexanediol, cyclohexanedimethanol aliphatic or aromatic diamines, such as ethylenediamine, piperazine, aminoethyl diethyl toluene diamine, as well as two phenyl Compounds with a nol hydroxyl group, such as resorcinol, catechol, hydroquinone Bisphenol, bisphenol A, bisphenol AP (1,1-bis(4-hydroxybenzoates) (hydroxyphenyl)-1-phenylethane), bisphenol F, bisphenol K, Bisphenol M, tetramethylbiphenol and o,o'-diallyl-bisphenol A In particular, compounds having two phenolic hydroxyl groups are preferred. stomach.

[0031] The isocyanate groups of the isocyanate-terminated polyether or diene polymer are then , and are capped by reacting with a capping agent. Suitable capping agents include See, for example, International Publication No. WO 2017 / 044359, incorporated herein by reference. These include various monophenols described further below. and polyphenolic compounds and various amine compounds, benzyl alcohol, hydroxy A small amount of functional acrylate or methacrylate compounds, thiol compounds, acetamide, etc. Examples include alkylamide compounds having at least one amine hydrogen and ketoxime compounds. can be done.

[0032] In some embodiments, at least 90% of the isocyanate groups are At least 95% of the isocyanate groups are capped with monophenols or polyphenols Examples of monophenols include phenol, each of which may contain 1 to 30 carbon atoms. Alkylphenols containing one or more alkyl groups, halogenated phenols, cardanol Suitable polyphenols include those having two or more units per molecule, such as phenols or naphthols. Preferably, it contains two phenolic hydroxyl groups and is suitable for resorcinol, catechol, Hydroquinone, biphenol, bisphenol A, bisphenol AP (1,1-bis(4 -hydroxyphenyl)-1-phenylethane), bisphenol F, bisphenol K, bisphenol M, tetramethylbiphenol and o,o'-diallyl-bisphenol In such embodiments, isosilane A and its halogenated derivatives are included. Up to 10%, preferably a maximum of 5%, of the anate groups may be capped with other capping agents as described above. It can be capped.

[0033] The capping reaction optionally involves capping the isocyanate groups with the isocyanates of a capping agent. under the general conditions already described in the presence of a catalyst to react with the nate-reactive group. The materials are mixed in the ratios listed below and reacted at room temperature or at a high temperature such as 60-120°C. This can be achieved by allowing the isocyanate content to remain constant (which is preferred). The reaction is continued until the isocyanate group content is reduced to 0.1% by weight or less. Less than 3%, preferably less than 1%, may remain uncapped.

[0034] The capping reaction is carried out by reacting the isocyanate-terminated polyether and / or diene polymer with This can be done at the same time as they are formed or as a separate capping step.

[0035] The resulting component B) material was analyzed by GP, considering only peaks representing molecular weights above 1000. C, suitably at least 3000, preferably at least 4,000 to Up to about 35,000, preferably up to about 20,000, more preferably up to about 15,000 It has a number average molecular weight.

[0036] The polydispersity (ratio of weight average molecular weight to number average molecular weight) of component B is suitably about 1 to about 4, preferably about 1.5 to 2.5.

[0037] Epoxy curing catalysts (component C) are one or more compounds that catalyze the reaction of epoxy resins with curing agents. It is preferably encapsulated or otherwise exposed to high temperatures. Among the preferred epoxy catalysts are ureas, e.g. p-Chlorophenyl-N,N-dimethylurea (monuron), 3-phenyl-1,1-di Methylurea (Fenuron), 3,4-dichlorophenyl-N,N-dimethylurea (Diuro) N-(3-chloro-4-methylphenyl)-N',N'-dimethylurea (chlorothion) urea), 2,4'-methylenebis(phenyldimethylurea), 4,4'-methylenebis (phenyldimethylurea) and 2,4-toluenebis(dimethylurea), 2,6-toluene Dimethylamine bis(dimethylurea), reaction products of dimethylamine and isophorone diisocyanate , tert-acryl- or alkyleneamines such as benzyldimethylamine, 2,4 , 6-tris(dimethylaminomethyl)phenol, piperidine or their derivatives, etc. , various aliphatic urea compounds, such as those described in EP 1916272 A1. It's like C1~C 12 Alkyleneimidazole or N-arylimidazoline 2-ethyl-2-methylimidazole or N-butylimidazole and 6- Prolactam. 2,4, integrated into a poly(p-vinylphenol) matrix. 6-tris(dimethylaminomethyl)phenol (see European Patent No. 0197892) as described) or 2,4,6-tris(dimethyl) aminomethyl)phenol (as described in U.S. Pat. No. 4,701,378) (including the following) is appropriate.

[0038] The hardener (component D) is used in combination with component C to provide an adhesive with a cure temperature of at least 60°C. The curing temperature is preferably at least 80°C, and more preferably at least 100°C. , at least 120°C, at least 130°C, or at least 140°C. For example, the curing temperature can be as high as 180°C. The "curing temperature" is the temperature at which the structural adhesive reaches its maximum curing temperature within 2 hours. The lap shear strength (DIN ISO 1465:2009-07) of the fully cured The lowest temperature at which at least 30% of the strength is achieved. Measurements were taken on samples cured at 0°C for 30 minutes, which represents the "fully cured" condition. Clean (degreased) 1.2mm HC420LAD+Z100 galvanized steel substrate, 1 A bond area of ​​0.05 × 25 mm and a bond thickness of 0.3 mm are appropriate parameters for performing this evaluation. It is a meter.

[0039] The hardener (ingredient D) reacts with at least two epoxy groups to form a bond between them. Suitable curing agents include boron trichloride / amine and boron trifluoride / Materials such as amine complexes, dicyandiamide, melamine, diallylmelamine, dicyandiamide Guanamines such as mido, methylguanidine, dimethylguanidine, trimethylguanidine , tetramethylguanidine, methylisobiguanidine, dimethylisobiguanidine, tetramethylguanidine Heptamethylisobiguanidine, Heptamethylisobiguanidine, Hexamethylisobiguanidine Nidin, acetoguanamine and benzoguanamine, 3-amino-1,2,4-triazolium aminotriazoles such as benzotriazole, hydrazides such as adipic acid dihydrazide, stearic acid Dihydrazide, isophthalic dihydrazide, semicarbazide, cyanoacetamide and di Aromatic polyamines such as aminodiphenyl sulfone, dicyandiamide, isopropyl alcohol, Phthalic dihydrazide, adipic dihydrazide and / or 4,4'-diaminodiphenyl The use of sulfones is particularly preferred.

[0040] Dicyandiamide (DICY, dicyanodiamide and 1- or 2-cyanoguanidine) DICY (CAS 461-58-5) is the compound of the empirical formula C2N4H4, molecular weight 84 and has the following structural formula (II): [ka]

[0041] Component E) is one or more curing agents. Any curing agent suitable for 2K epoxy adhesive compositions may be used. In other words, the curing agent of the present invention can be used for epoxy bonding at non-high temperatures. In one embodiment, the curing agent of the present invention allows the curing of the epoxy resin. The preferred curing agent is a polymeric amine (polyamide ) and polymeric amides (polyamides) (including, for example, polyamidoamines), low molecular weight amines and combinations thereof. Preferably, the curing agent contains a primary amine group, a secondary amine group, and a The amine groups include one or more of a primary amine group, a mercapto group, and / or a phenol group.

[0042] One preferred polyamine is a polyetheramine-epoxy adduct, i.e., Examples include the reaction product of a stoichiometric excess of an amine prepolymer with an epoxy resin. The amine is preferably contained in the hardener composition, more preferably only in the hardener composition. Polyamine curing agents tend to react slower than low molecular weight amines, but they This can add flexibility to the adhesive.

[0043] Amine prepolymers contain at least two amine groups to allow crosslinking to occur. The amine prepolymer may be any amine prepolymer having a primary and and / or secondary amine groups, preferably primary amine groups. The monomers include polyether diamines, polyether triamines, and mixtures thereof. Polyethertriamine is preferred. The polyetheramine may be linear, branched, or the like. or mixtures thereof. Branched polyetheramines are preferred. Polyetheramines of any molecular weight may be used. Amines having molecular weights in the range of 200 to 6000 or more are suitable. The molecular weight may be greater than 1000, or more preferably greater than 3000. A molecular weight of 3000 or 5000 is preferred.

[0044] Suitable commercially available polyetheramines include those available from Huntsman and Jeffamin Suitable polyether diamines include those sold under the trade name e. These include the Jeffamine D, ED and DR series. mine D-230, D-400, D-2000, D-4000, HK-511, ED -600, ED-900, ED-2003, EDR-148 and EDR-176 Suitable polyether triamines include the Jeffamine T series. These include Jeffamine T-403, T-3000, and T-5000. Polyether triamines are preferred, with polyether triamines of about 5000 molecular weight being preferred. An amine (e.g., Jeffamine T-5000) is most preferred. Equivalents may also be used in partial or total replacement.

[0045] When polyamide is included, any polyamide curing agent can be used. Some preferred polyamides include the reaction products of dimerized fatty acids and polyamines. Examples of such polyamides are Versamid 115, Versamid 125 and those available from Cognis under the tradenames Versamid.

[0046] Alternatively, the curing agent can be a low molecular weight (non-polymeric) amine-based curing agent. preferably functions as a cross-linking agent and / or chain extender. Preferred cross-linking agents include: Primary and / or secondary amines may be mentioned.

[0047] Preferred crosslinkers typically have a crosslinking capacity of up to 300 g / mol, 250 g / mol or 200 g / mol Preferred crosslinkers typically have a molecular weight of at least 48 g / mol or 60 g / mol Some preferred molecular weights include 60 g / mol, 103 g / mol, 1 Some preferred crosslinkers and / or chain extenders include 29 g / mole and 170 g / mole. The lengthening agents include triethylenetetramine (TETA) and diethylenetriamine (DETA ), isophorone diamine (IPDA) and ethylene diamine.

[0048] The curing agent is used to prevent the combined components of the epoxy adhesive composition of the present invention from becoming too viscous, e.g., To allow curing / partial curing at an appropriate temperature before a full curing heat treatment, such as during cooling The pre-curing temperature is preferably 80°C to It is 120°C.

[0049] Unless otherwise specified, all weight percentages are based on the total weight of the epoxy adhesive composition. .

[0050] Component A) comprises at least 20% by weight of the total weight of the epoxy adhesive composition, at least 3 It may constitute 0% or at least 40% by weight, up to 80%, 70% or may constitute up to 60% by weight.

[0051] Component B) comprises at least 0.5 wt. % of the total weight of the epoxy adhesive composition, at least 2% by weight, at least 5% by weight, at least 10% by weight or at least 15% by weight It may comprise up to 40%, up to 30% or up to 25% by weight of the total weight of the hydroxybenzoates.

[0052] Component C) is at least 0.1% by weight, at least 0.25% by weight, based on the total weight of components A to E. % or at least 0.5% by weight, for example up to 5% by weight of the total weight of components A to E , may constitute up to 3% by weight or up to 2% by weight.

[0053] Component D) is sufficient to consume at least 80% of the epoxide groups present in the composition. A large excess over that required to consume all of the epoxide groups is usually present. Preferably, the curing agent is at least 1% by weight of the adhesive, more preferably at least The curing agent preferably comprises at least 2% by weight, and even more preferably at least 3% by weight. or up to about 15% by weight of the adhesive, up to about 10% by weight of that, up to about 8% by weight of that, It may constitute up to about 7% by weight or up to about 5% by weight thereof.

[0054] Component E) is present in the epoxy adhesive composition in an amount of 1.5% by weight or more of the epoxy adhesive. , more preferably present in an amount of 3% by weight or more, more preferably 9% by weight or more. In the epoxy adhesive composition, the amount of the epoxy adhesive is 50% by weight or less of the epoxy adhesive composition, more preferably Preferably it is present in an amount of 34% by weight or less, more preferably 21% by weight or less.

[0055] The weight of components A to E may be, for example, 30 to 100%, 50 to 100%, or Components A to E may comprise 50 to 90% or 50 to 85% of the total weight of the adhesive. If it does, the adhesive will also contain one or more optional ingredients.

[0056] Optional ingredients include one or more rubbers (different from ingredient B). These include, for example: For example, rubber-modified epoxy resins, i.e., at least 300 g / mol, preferably at least 5 A compound having at least two epoxide groups separated by an aliphatic chain of 0.00 g / mol. The aliphatic chain may be, for example, an alkylene group; an alkenyl group; a diene polymer or copolymers; or polyethers, such as poly(propylene oxide), poly(ethylene oxide), Oxide) or copolymers of propylene oxide and ethylene oxide. The rubber-modified epoxy resins include epoxidized fatty acids (which are dimerized or oligomerized and elastomeric polyesters modified to contain epoxy groups. The rubber-modified epoxy resin is heated to -20°C or below, preferably -30°C or below before curing. The glass transition temperature may be lower than 100°C.

[0057] The optional rubber, if present, comprises core-shell rubber particles that account for a maximum of 100% of the total weight of the adhesive. Core-shell rubber particles may be included, provided that they constitute 7 percent by weight. For example, core-shell rubber may comprise 5% or less, 2.5% or less, or 1% or less of the total weight of the adhesive. And, adhesive may not be required.

[0058] The adhesive may contain one or more particulate fillers. The fillers are cured at a temperature reached in the curing reaction. These fillers (1) modify the rheology of the adhesive in a desirable way; (2) reducing the overall cost per unit weight; (3) preventing contact with water or oil. (4) Absorption from the adhesive or from the substrate to which it is applied; and / or (5) Adhesion failure. Examples of suitable mineral fillers are: Calcium carbonate, calcium oxide, talc, carbon black, textile fibers, glass Particles or fibers, aramid pulp, boron fiber, carbon fiber, mineral silicates, mica, powder Quartz, hydrated aluminum oxide, bentonite, wollastonite, kaolin, fumed Silica, silica aerogel, polyurea compounds, polyamide compounds, aluminum powder or Metal powders such as iron powder and expandable microballoons are included. Contains silica and calcium oxide, calcium carbonate, kaolin and / or wollastonite Mixtures of fillers can be used which may further include particulate fillers. may constitute at least 5, at least 10, or at least 12% of the total weight of the adhesive; It may comprise up to 5%, up to 30%, up to 25%, or up to 20%. If it contains fumed silica, the adhesive may contain up to 10% by weight, preferably 1 to 6% by weight, of fumed silica. It may contain silica.

[0059] All or part of the mineral filler has a diameter of 1 to 50 μm (D50, measured by microscope). The fiber diameter may be in the form of a fiber having an aspect ratio of 2 to 3. The thickness may be 0 μm or 2 to 16 μm, and the aspect ratio may be 8 to 40 or 8 to 20. The diameter of a fiber is taken as the diameter of a circle having the same cross-sectional area as the fiber. The aspect ratio of a fiber is , 6 to 40, 6 to 25, 8 to 20, or 8 to 15, or more.

[0060] Alternatively, all or part of the mineral filler may have an aspect ratio of 5 or less, in particular 2 or less, and 1 Low aspect ratio particle morphology with a longest dimension of up to 0.00 μm, preferably up to 25 μm It could be.

[0061] The adhesive of the present invention has an average particle size of up to 200 microns and a density of 0.4 g / cc Up to 100 glass microballoons may be present. If present, they may be present in a volume greater than the total weight of the adhesive. It may be used in an amount of up to 5%, more preferably up to 2% or up to 1% thereof. Suitable microballoons include 3M® Glass from 3M Corporation. s Bubbles K25. Thus, in some embodiments, glass micro The closar balloon is present in an amount of 0.5% or less or 0.25% or less of the total weight of the adhesive. may or may not be present.

[0062] Monomeric or oligomeric addition polymerizable ethylenically unsaturated materials are optionally included in the adhesive composition. This material must have a molecular weight of less than about 1500. The material may be, for example, an acrylate or methacrylate compound, an unsaturated polyester, a vinyl ester, or the like. This material may be an epoxy adduct of a ster resin or an unsaturated polyester resin. A free radical initiator is also included in the adhesive composition to provide a source of free radicals for the polymerization. By including this type of ethylenically unsaturated material, This offers the possibility of in-situ curing of the adhesive by selective polymerization of the olefinic unsaturation.

[0063] The adhesive contains dimerized fatty acids, reactive diluents, pigments and dyes, flame retardants, thixotropic agents. The composition may further contain other additives such as foaming agents, flow control agents, adhesion promoters and antioxidants. Suitable foaming agents include both physical and chemical type agents. As described in WO 2005 / 118734, It may also contain thermoplastic powders such as polybutyral or polyester polyols.

[0064] The adhesive preferably contains no more than 2 parts by weight of plasticizer per part by weight of component B). It may contain not more than 1 part, not more than 0.5 parts, or not more than 0.1 parts of a plasticizer on the same basis; For the purposes of the present invention, a plasticizer is defined as a component A) that is a) be a liquid at room temperature (23°C) and soluble at room temperature; b) have a molecular weight of at least 100 g / mol; c) has a boiling point temperature of at least 150°C, and d) has epoxide groups and epoxide If a plasticizer is present, it is preferably a material that does not have reactive groups. Also, the boiling point temperature is 210°C. Examples of plasticizers include alkylnaphthalenes, dialkylnaphthalenes, alkyl-substituted aromatic hydrocarbons such as benzene, alkylbenzene, and dialkylbenzene; talic acid esters, trimellitic acid esters, adipic acid esters, maleic acid esters, Benzoic acid esters, terephthalic acid esters, various fatty acid esters, epoxidized vegetable oils, Sulfonamides, alkyl citrates, acetylated monoglycerides, tricresyl phosphate, Diphenylcresyl phosphate, isopropyl triphenyl phosphate, 2-ethylhexyl phosphate Isodecyldiphenyl phosphate, Isodecyldiphenyl phosphate, Triphenyl phosphate, Tributoxy phosphate In certain embodiments, the adhesive comprises a carboxylic acid ester plasticizer, Free of sulfonamide and phosphate ester plasticizers.

[0065] In one embodiment, the present invention provides a composition comprising: i) a first component, A) one component that is liquid at 23°C; The above epoxy resin and B) one or more reactive compounds having a capped isocyanate group C) a polymer containing a urethane group and / or a urea group, C) an epoxy curing catalyst, and D) dicyandiamide. ii) a second component comprising E) a curing agent; and mixing the same to form an epoxy adhesive composition.

[0066] This innovative adhesive can be applied to any part in an auto body shop. The adhesive can be mixed in any suitable manner using equipment equipped with a static or dynamic mixing head. It can be applied using a simple two-component application technique. The use of dynamic mixheads is more effective. Preferably, the first component of the adhesive composition is a completely applicable adhesive without the second component (i.e., a curing agent). It can be a fully functional 1K automotive body shop structural adhesive. is in areas of the part where thermal pre-cure is applied by any method such as IR pre-cure The adhesive composition of the present invention containing both components is applied. This technology can also be applied to oven pre-curing processes.

[0067] In one embodiment, the adhesive composition of the present invention (i.e., comprising the first and second components described above) (including the first component) are applied alternately with applications of the first component alone. In this embodiment, the second component is The desired feed ratios are applied in the desired joint areas to allow for thermal pre-curing in these areas. The first component is mixed with the second component at 200°C.

[0068] In other areas, the hardener (alternatively called accelerator paste or second component) is again applied. It can be turned off and a single first component can be used. Preferably, the application technique / equipment The accelerator paste in the second component can be quickly mixed into the adhesive mixture in the first component. Dynamic mixing was used to enable the

[0069] the aforementioned adhesive composition is layered at a bond line between two substrates to form an assembly; The adhesive layer is cured at the bond line to form a cured adhesive bonded to each of the two substrates. do.

[0070] The adhesive can be applied to the substrate by any convenient technique. Depending on the application, it can be applied cold or warm. Manually and / or robotically using a king gun, other extrusion device or jet spray method Once the adhesive composition has been applied to at least one surface of the substrate, The substrates are brought into contact so that the adhesive is located at the bond line between the substrates.

[0071] After application, the adhesive can be further cured by heating it above its cure temperature. In some cases, especially if longer cure times are acceptable, lower temperatures may be used. However, the curing process is generally carried out by heating the adhesive to at least 130°C. The heating temperature may be 220°C or higher, but the advantage of the present invention is that , because the curing initiation temperature is lower, the curing temperature is preferably 180 ° C to 200 ° C up to 170°C or up to 165°C.

[0072] In one embodiment of the present invention, in the first step, the mixture is and B) one or more epoxy resins having a capped isocyanate. C) an epoxy curing catalyst; and D) a reactive urethane group and / or urea group-containing polymer. A first epoxy adhesive composition containing cyandiamide is applied to the substrate, followed by A) one or more epoxy resins that are liquid at 23°C; and B) a capped isopropyl alcohol. C) one or more reactive urethane and / or urea group-containing polymers with cyanate; A second epoxy adhesive comprising an epoxy curing catalyst, D) dicyandiamide, and E) a curing agent. The second step involves applying the agent composition to a substrate. If necessary, repeat the test more than twice, for example, 2, 3, 4, 5, 6, 7, 8, 9 times, or up to 20 times or more. In a preferred embodiment, components A) and B) of the first epoxy adhesive composition ), C) and D) are the same as components A), B), C) and D) of the second epoxy adhesive composition. and a curing agent E) is mixed into the first epoxy adhesive composition to form the second epoxy adhesive. An adhesive composition is prepared.

[0073] The adhesive of the present invention is suitable for use on wood, metal, coated metal, steel, zinc, copper, bronze, magnesium, Metals such as titanium and / or aluminum, various plastics and filled plastics It can be used to bond a variety of substrates together, including wood substrates, fiberglass, etc. In a preferred embodiment, the adhesive bonds parts of an automobile together or It is used to connect parts to the automobile.

[0074] The substrates can be different materials. An example of a substrate combination is steel and aluminum. Combinations of different metals such as aluminum, steel and magnesium, and aluminum and magnesium A combination of metals such as steel, magnesium, aluminum or titanium with thermoplastic organic polymers. In combination with polymeric materials such as polymers or thermosetting organic polymers, as well as steel, aluminum Metals such as aluminum, magnesium, or titanium with carbon fiber composites or glass fiber composites Examples of such a material include a combination with a fiber composite material such as a polyester fiber.

[0075] Applications of particular interest include the attachment of automobile or other vehicle frame components to each other or to other structures. The joining to the finished parts.

[0076] Assembled automobile and other vehicle frame components are coated with coatings that require bake hardening. They are often coated with a coating material, such as an e-coat. Typically, it is fired at temperatures that can range as high as 160°C to 210°C. Apply the epoxy adhesive composition of the present invention to the frame / component in a sufficient amount and / or position. to hold them in place, then a coating is applied, followed by the bonding of the present invention. The adhesive and any other adhesives can be cured while simultaneously baking and curing the coating. The epoxy adhesive composition of the present invention and optionally one or more additional applying an additional epoxy adhesive composition (different from the composition of the present invention); Between the steps of applying the adhesive, the assembly substrate is held in the adhesive layer of the present invention until the curing step is performed. The adhesive composition holds the pieces in a fixed position relative to one another. Steps can be used as fixing devices. These include, for example, can be removed by temporary mechanical means such as various types of clamps, bands, etc. For example, various types of welding, riveting, screwing and / or crimping methods The mechanical fixing means may be permanent. Alternatively or additionally, a coating may be applied. The adhesive assembly is then cured while the rest of the adhesive remains uncured until the final curing step is performed afterwards. Spot-cure one or more specific portions of the composition to create one or more localized bonds between substrates. Fixation can be achieved by forming a bond.

[0077] The uncured adhesive has a viscosity of at least 25 Pa, at least 50 Pa or At least 70 Pa, up to 1000 Pa, up to 700 Pa, up to 400 Pa or 200 Pa The plastic viscosity of the tungsten carbide may be up to 1000 MPa.

[0078] The cured adhesive forms strong bonds with a variety of substrates.

[0079] The cured adhesive in some embodiments was prepared according to the following examples. At least 12MPa, at least 14MPa, at least 16MPa, measured with a sample Pa, indicating a lap shear strength in the unaged state of up to 18 MPa. [Example]

[0080] The following examples are offered to illustrate the present invention but are not intended to limit its scope. Not intended. All parts and percentages are by weight unless otherwise specified. Adhesives and Hardeners The raw materials used are shown in Table 1.

[0081] [Table 1]

[0082] [Table 2]

[0083] [Table 3]

[0084] Toughener A is an elastomeric toughener containing blocked isocyanate groups. This is polytetrahydrofuran (PolyTHF 2000) with a molecular weight of 2000. 0.41 parts of a 2800 molecular weight hydroxyl-terminated polybutadiene polymer (POLYVE 16.81 parts of hexafluoropropanediol (ST HT) was mixed at 120°C, and the mixture was cooled to 60°C. 12.58 parts of ethylene diisocyanate and a tin urethane catalyst were added, and the resulting reaction mixture was The mixture is prepared by heating the mixture to 85°C under nitrogen for 45 minutes. Then, 7.09 parts of o ,o'-Diallylbisphenol A (ODBA) was added and the mixture was heated under vacuum at 100°C. Stir in the bath for 120 minutes. Add 13.05 parts of cardanol and reduce the mixture to 1 Stir in a 0.5°C bath for 240 minutes.

[0085] Examples 1 to 6 are epoxy resin formulations. Examples 1 and 4 are dicyandiamide formulations. Examples 2 and 5 are conventional structural adhesives that do not contain latent curing agents or catalysts, such as The catalyst was added to the formulations of Examples 1 and 4, respectively. Examples 3 and 6 were the same formulations as those of Examples 1 and 4, respectively. The same formulations as in Examples 1 and 4, respectively, were used, with dicyandiamine in combination with a latent catalyst. Contains do.

[0086] [Table 4]

[0087] A hardener used to pre-cure epoxy resins (Examples 1 to 6) for rapid fixation. The curing agent composition is shown in Table 3. Example 7 is a 2:1 mixture that fully cures the epoxy component. It is a conventional 2K hardener composition designed to pre-heat the epoxy component in a 4:1 mixture. Example 8, designed to cure, is an amine-terminated polyether polyol and 4, 7, A low molecular weight diamine, 10-trioxatridecane-1,13-diamine, and ca. 60% % of the amine end-strengthening agent ATBN and 6% of K54 as a catalyst. 1. Using different amounts of TETA to achieve rapid strength development after induction hardening Examples 9 and 10 are designed to pre-cure the epoxy component in a 4:1 mixture. Example 11 is designed to pre-cure the epoxy component in a 10:1 mixture. It has been done.

[0088] [Table 5]

[0089] The following tests are performed on the epoxy adhesive compositions: "Rheology" is rotational viscosity / yield stress, measured with a Bohlin CS-50 rheometer -, C / P20, Rise / Fall 0.1~20s -1 is determined according to the Casson model. and is evaluated accordingly. "Lap shear strength" is DIN EN1465:200 on DX56Z / DC04ZE 9-07 (thickness 0.7 mm; ANTICORIT PL 3802-3 Re-greased with 9S; joint area 10 x 25 mm, adhesive layer thickness 0.3 mm).

[0090] Adhesion test samples are prepared as follows: Metal strips of a given steel grade were cleaned in an ultrasonic bath with heptane and then washed with heptane / AN Dip-coated in a solution of TICORIT PL 3802-39S (9 / 1) Apply grease again by

[0091] "Lap shear specimens" are prepared by applying the adhesive composition to a strip Glass beads (0.2 mm) are sprinkled on top of the adhesive layer before the test strip is The two strips are overlapped with a 10mm overlap to hold them together during the firing cycle. Metal clips are used for induction curing. The induction curing was carried out at 120°C for 1 minute. Heat was achieved within 15 seconds. All specimen / adhesive assemblies were heated to 180°C for 30 minutes. The mixture was fully cured at 165°C for 25 minutes or 165°C for 25 minutes.

[0092] Table 4 shows the composition (epoxy resin and curing agent) and the comparative examples of Examples 12 to 17. The lap shear strength was measured by induction hardening at 120°C for 1 minute. After curing and after hardening in an oven at 165°C for 25 minutes, mild steel DX56Z / DC Tested on 04ZE.

[0093] [Table 6]

[0094] Examples 12 to 17 shown in Table 4 show that when applied together with a curing accelerator (Example 12b, 13b, 14b, 15b, 16b, and 17b) were expressed in induced hardening for rapid fixation. Lap shear strength and full cure after application without accelerator in a 165°C oven for 25 minutes (Examples 12a, 13a, 14a, 15a, 16a and 17a) Formulations without latent hardeners exhibit no significant improvement when applied with an accelerator / hardener component. In this case, the strength is only developed quickly under induction curing at 120°C for 1 minute. After oven curing without annealing, the final lap shear strength is insufficient.

[0095] Table 5 shows the composition (epoxy resin and curing agent) and Examples 18 to 20 of the present invention. This document summarizes the test results for the mechanical performance of 3.

[0096] [Table 7]

[0097] Examples 18a and 19a are epoxy resins applied without an accelerator paste. and exhibits no handling strength when induction cured and after oven curing conditions of 165°C for 25 minutes. Example 18b is applied with the accelerator of Example 9 and fully cures with high lap shear strength. The epoxy resin used was Example 3, and the resulting pressure was 4.3 MPa during the induction process at 120°C for 1 minute. Example 19b shows the improvement in strength to reach the handling strength. Epoxy applied using a 10:1 mix ratio of TETA (containing more than 10% TETA) Resin Example 3, exhibiting a handling strength of 0.2 MPa after the induction process. After curing, Examples 18b and 19b both exhibited fully cured polymers with excellent lap shear strength. Examples 20a, 21a, 22a and 23a are obtained without the accelerator paste. Epoxy resin Example 6 applied at 165°C, which did not have handling strength when induction cured. Fully cured with high lap shear strength after oven cure conditions of 25 minutes at 40°C. Example 20b , 21b, 22b and 23b are applied with accelerator paste (Examples 8 to 11, respectively). This is epoxy resin Example 6, which has a handling strength of 0.7 to 7.1 MPa after induction curing. and exhibits full cure with high lap shear strength after oven cure conditions of 165°C for 25 minutes.

Claims

1. In the mixture, A) one or more epoxy resins that are liquid at 23°C; B) one or more reactive urethane groups with capped isocyanates and / or urethanes a hydroxyl group-containing polymer; C) an epoxy curing catalyst; and D) dicyandiamide, E) a curing agent; Epoxy adhesive composition comprising: The above lap shear strength according to DIN EN 1465:2009-07 and and after 25 minutes of curing, a lap shear strength of greater than 15 MPa, said lap shear strength being , both 0.8mm thick hot dip galvanized steel DX56D and 0.8mm thick electrolytic zinc Measured in combination with galvanized steel DC04 (DIN EN 10346:2015 -10) Epoxy adhesive composition.

2. 10. The epoxy resin of claim 1, wherein component A comprises a diglycidyl ether of a bisphenol. Adhesive composition.

3. The capped isocyanate groups of component B may be monophenols or polyphenols.

10. The epoxy adhesive composition of claim 1 which is capped.

4. 10. The epoxy adhesive composition of claim 1, wherein component C comprises a urea compound.

5. Component E is a hydroxyl group selected from the group consisting of a primary amine group, a secondary amine group, a mercapto group, and / or a phenol group.

10. The epoxy adhesive composition of claim 1, comprising one or more of:

6. 0 to 0.75 wt % of glass microspheres based on the weight of the epoxy adhesive composition.

2. The epoxy adhesive composition of claim 1, comprising:

7. i) a first component, A) one or more epoxy resins that are liquid at 23°C; B) one or more reactive urethane groups with capped isocyanate groups and / or a urea group-containing polymer; C) an epoxy curing catalyst; and D) dicyandiamide and a first component comprising i) a second component, E) Hardener and a second component comprising: The epoxy adhesive composition has a compressive strength of 0.2 MPa or more after induction curing at 120°C for 1 minute. , lap shear strength according to DIN EN 1465:2009-07 and 25 min at 165°C and after curing between the two, the lap shear strength is greater than 15 MPa, and Both are 0.8mm thick hot dip galvanized steel DX56D and 0.8mm thick electrogalvanized steel Measured in combination with steel DC04 (DIN EN 10346:2015-10 ),method.

8. Method for applying a first epoxy adhesive composition and a second epoxy adhesive composition to a substrate And, 1) In the mixture: A) one or more epoxy resins that are liquid at 23°C; B) one or more reactive urethane groups with capped isocyanates and / or urethanes a hydroxyl group-containing polymer; C) an epoxy curing catalyst; and D) dicyandiamide and applying the first epoxy adhesive composition to a substrate; 2) In the mixture: A) one or more epoxy resins that are liquid at 23°C; B) one or more reactive urethane groups with capped isocyanates and / or urethanes a hydroxyl group-containing polymer; C) an epoxy curing catalyst; and D) dicyandiamide, E) a curing agent; applying to the substrate the second epoxy adhesive composition comprising: Both epoxy adhesive compositions had a modulus of more than 15 MPa after curing at 165°C for 25 minutes. The above lap shear strength according to DIN EN 1465:2009-07 is The shear strength of both 0.8 mm thick hot dip galvanized steel DX56D and 0.8 mm thick Measured on a combination of electrogalvanized steel DC04 (DIN EN 1034 6:2015-10), Methods.

9. 9. The method of claim 8, wherein steps 1 and 2 are repeated two or more times.

10. Components A), B), C) and D) of the first epoxy adhesive composition are The components A), B), C) and D) of the epoxy adhesive composition are the same as those of the epoxy adhesive composition, and the method comprises step 1. and between steps 1 and 2, mixing the curing agent E) into the first epoxy adhesive composition. The method of claim 8 further comprising the step of preparing the second epoxy adhesive composition.

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