adhesive composition

Abstract

Provided herein are expanding epoxy adhesives.

Description

[Technical Field]

[0001] The present invention relates to the field of thermally expandable adhesive compositions. [Background technology]

[0002] The current state-of-the-art in thermally expandable adhesives for joining automotive metals relies on expandable thermoplastics, epoxy and acrylic tapes, and hot melt adhesives to aid in cavity sealing and reinforcement. Thermally expandable structural epoxy adhesives offer excellent strength, water absorption properties, and metal adhesion, as well as favorable processability for automotive assembly applications. However, the effectiveness of expandable structural epoxy adhesives applied to large gaps is limited by the large amount of heat released during the ring-opening polymerization of the epoxide, which can cause peak core temperatures within the adhesive layer to significantly exceed the cure temperature, ultimately leading to thermal degradation of the adhesive.

[0003] There is a need for an epoxy-based structural adhesive paste that provides reduced peak core temperatures and can be used for large gap applications. Summary of the Invention [Means for solving the problem]

[0004] In a first aspect, the present invention provides a method for producing a medicament for the treatment of a pulmonary arthritis, comprising: (A) at least one liquid epoxy resin; (B) at least one blowing agent; (C) at least one hardener; (D) at least one semi-crystalline thermoplastic in particulate form; The present invention provides an expandable adhesive composition comprising:

[0005] In a second aspect, the present invention provides a method of bonding substrates, comprising: (1) providing an expandable adhesive composition, comprising: (A) at least one liquid epoxy resin; (B) at least one blowing agent; (C) at least one hardener; (D) at least one semi-crystalline thermoplastic in particulate form; (2) applying the expandable adhesive composition to a substrate; (3) expanding the expandable adhesive composition; and (4) A step of curing the expandable adhesive composition The present invention provides a method comprising:

[0006] In a third aspect, the present invention provides a bonded assembly comprising substrates bonded by an adhesive resulting from the expansion and curing of an expandable adhesive composition, (A) at least one liquid epoxy resin; (B) at least one blowing agent; (C) at least one hardener; (D) at least one semi-crystalline thermoplastic in particulate form;

[0010] A bonded assembly is provided, comprising: DETAILED DESCRIPTION OF THE INVENTION

[0007] The inventors have discovered that by incorporating at least one semi-crystalline thermoplastic in particulate form, it is possible to achieve an expandable epoxy adhesive with a reduced core temperature during cure. Such expandable epoxy adhesive pastes can be robotically applied to oily vehicle panels during automated assembly processes to fill and reinforce cavities, thereby saving time and money. Specifically, they have found that particulate semi-crystalline thermoplastic resins, such as polyamides, copolyetheresters, and polyesters, significantly reduce the peak core temperature reached in the expandable epoxy paste during cure.

[0008] Definitions and Abbreviations ATH Aluminum trihydroxide, alumina trihydrate MDI 4,4'-methylenebis(phenylisocyanate) HDI Hexamethylene Diisocyanate HEMA Hydroxyethyl Methacrylate IPDI Isophorone Diisocyanate PTMEG Poly(tetramethylene oxide) glycol PU Polyurethane SEC size exclusion chromatography RH Relative Humidity CF cohesive failure AF adhesive failure M p Peak molecular weight, molecular weight of the highest peak FTIR Fourier Transform Infrared PBT Poly(butylene terephthalate)

[0009] Equivalent weight and molecular weight are determined by gel permeation chromatography (GPC).

[0010] At least one liquid epoxy resin (A) The adhesive of the present invention comprises at least one liquid epoxy resin, the expression liquid epoxy resin including all epoxy resins that are flowable at 25°C and preferably have a viscosity at 25°C of less than 1,500,000 mPa.s, measured according to ASTM D-445.

[0011] In a preferred embodiment, the at least one epoxy resin comprises or consists of an epoxy resin having a viscosity of less than 50,000 mPa.s, more preferably less than 20,000 mPa.s at 25°C, as measured according to ASTM D-445.

[0012] Examples of suitable epoxy resins are those formed by the reaction of epichlorohydrin with bisphenols, particularly bisphenol A, bisphenol AP, bisphenol AF, bisphenol BP, bisphenol B, bisphenol C, bisphenol E, bisphenol F, bisphenol G, bisphenol M, bisphenol S, bisphenol P, bisphenol Z, and novolac epoxy resins, which are the reaction products of epichlorohydrin with novolac resins. Novolac resins are made from the reaction of phenol with formaldehyde and are epoxy resins obtained from the reaction of epichlorohydrin with various diols (other than bisphenols), such as dihexanediol diglycyl ether.

[0013] Epoxy resins obtained from the reaction of epichlorohydrin with bisphenol A are particularly preferred.

[0014] In a particularly preferred embodiment, the at least one epoxy resin comprises or consists of an epoxy resin obtained from the reaction of epichlorohydrin with bisphenol A and has a viscosity of less than 50,000 mPa s, more preferably less than 20,000 mPa s, at 25°C, measured according to ASTM D-445.

[0015] In a preferred embodiment, the at least one liquid epoxy resin comprises the liquid reaction product of epichlorohydrin and bisphenol A and has an epoxide equivalent weight of 182 to 192 g / eq (as measured according to ASTM D-1652), an epoxide percentage of 22.4 to 23.6% (as measured according to ASTM D-1652), an epoxide group content of 5,200 to 5,500 mmol / kg (as measured according to ASTM D-1652), a viscosity of 11,000 to 14,000 mPas at 25°C (as measured according to ASTM D-445), and a functionality of 2.

[0016] The at least one liquid epoxy resin is preferably used in an amount of 10 to 65% by weight, more preferably 35 to 60% by weight, and most preferably 40 to 55% by weight, based on the total weight of the adhesive composition.

[0017] In a preferred embodiment, the at least one epoxy resin comprises or consists of an epoxy resin having a viscosity of less than 1,500,000 mPa.s at 25°C, measured according to ASTM D-445, and is used in an amount of 10 to 65 wt. %, more preferably 35 to 60 wt. %, and most particularly preferably 40 to 55 wt. %, based on the total weight of the adhesive composition.

[0018] In a preferred embodiment, the at least one epoxy resin comprises or consists of an epoxy resin having a viscosity of less than 50,000 mPa.s, more preferably less than 20,000 mPa.s, at 25°C, measured according to ASTM D-445, and is used in an amount of 10 to 65 wt. %, more preferably 35 to 60 wt. %, and more particularly preferably 40 to 55 wt. %, based on the total weight of the adhesive composition.

[0019] In another preferred embodiment, the at least one epoxy resin comprises or consists of an epoxy resin formed by the reaction of epichlorohydrin with a bisphenol, in particular bisphenol A, bisphenol AP, bisphenol AF, bisphenol BP, bisphenol B, bisphenol C, bisphenol E, bisphenol F, bisphenol G, bisphenol M, bisphenol S, bisphenol P, bisphenol Z, and is used in an amount of 10 to 65% by weight, more preferably 35 to 60% by weight, and more particularly preferably 40 to 55% by weight, based on the total weight of the adhesive composition.

[0020] In another preferred embodiment, the at least one epoxy resin comprises or consists of an epoxy resin obtained from the reaction of epichlorohydrin with bisphenol A and is used in an amount of 10 to 65 wt. %, more preferably 35 to 60 wt. %, and more particularly preferably 40 to 55 wt. %, based on the total weight of the adhesive composition.

[0021] In another preferred embodiment, the at least one epoxy resin comprises or consists of an epoxy resin obtained from the reaction of epichlorohydrin with bisphenol A and has a viscosity of less than 50,000 mPa.s, more preferably less than 20,000 mPa.s, at 25°C, measured according to ASTM D-445, and is used in an amount of 10 to 65 wt. %, more preferably 35 to 60 wt. %, and more particularly preferably 40 to 55 wt. %, based on the total weight of the adhesive composition.

[0022] In another embodiment, the at least one liquid epoxy resin comprises a liquid reaction product of epichlorohydrin and bisphenol A and has an epoxide equivalent weight (as measured according to ASTM D-1652) of 182 to 192 g / eq, an epoxide proportion (as measured according to ASTM D-1652) of 22.4 to 23.6%, an epoxide group content (as measured according to ASTM D-1652) of 5,200 to 5,500 mmol / kg, a viscosity at 25°C (as measured according to ASTM D-445) of 11,000 to 14,000 mPas, and a functionality of 2, and is used in an amount of 10 to 65 wt. %, more preferably 35 to 60 wt. %, and most particularly preferably 40 to 55 wt. %, based on the total weight of the adhesive composition.

[0023] at least one blowing agent (B) The adhesive composition of the present invention includes at least one blowing agent.

[0024] The blowing agent is preferably selected from physical blowing agents, which are low boiling molecules or trapped or entrapped gases, and chemical blowing agents, which are molecules that decompose during curing to release a gas.

[0025] Suitable physical blowing agents consist of expandable graphite and gases (e.g., hydrocarbons such as butane, pentane, etc.) and low boiling point molecules such as water, nitrogen, carbon dioxide, propane, butane, and pentane encapsulated in a polymeric shell such as poly(acrylonitrile) or acrylate copolymers.

[0026] Suitable chemical blowing agents include: 1. Isocyanate 2. Azo compounds (e.g., azobisisobutyronitrile, diisopropyl azodicarboxylate, azodicarbonamide) 3. Hydrazine derivatives [e.g., 4,4'-oxybis(benzenesulfonylhydrazide), p-toluenesulfonylhydrazide] 4. Semicarbazides and sulfonylsemicarbazides [e.g., p-toluenesulfonylsemicarbazide, 4,4'-oxybis(benzenesulfonylsemicarbazide), p,p-oxybisbenzenesulfonylhydrazide] 5. N-nitroso compounds (e.g., dinitrosopentamethylenetetramine) 6. Tetrazoles (e.g., 5-phenyltetrazole, 5-aminotetrazole) 7. Poly(hydrosiloxane) 8. Salts of carbonic and polycarboxylic acids (e.g., sodium bicarbonate) 9. Peroxides (e.g., peroxyhexanoate, peroxydicarbonate).

[0027] In a preferred embodiment, the blowing agent comprises or consists of a physical blowing agent, more preferably a hydrocarbon gas encapsulated in a polymer, especially isooctane, isobutane or isopentane encapsulated in acrylonitrile.

[0028] In another preferred embodiment, the blowing agent comprises or consists of a chemical blowing agent, in particular an azo compound, more particularly azodicarbonamide.

[0029] In another preferred embodiment, the blowing agent is a mixture of a physical blowing agent and a chemical blowing agent, for example, a mixture of isooctane, isobutane, or isopentane encapsulated in acrylonitrile and azodicarbonamide.

[0030] The foaming agent is preferably used in an amount of 0.25 to 10% by weight, more preferably 0.5 to 5% by weight, and even more preferably 0.75 to 1.5% by weight, based on the total weight of the adhesive composition.

[0031] In a preferred embodiment, the blowing agent is selected from physical blowing agents, which are low-boiling molecules or trapped or encapsulated gases, and chemical blowing agents, which are molecules that decompose during curing to release a gas, and is used in an amount of 0.25 to 2.35 wt. %, more preferably 0.5 to 2.15 wt. %, and most preferably 0.75 to 1.5 wt. %, based on the total weight of the adhesive composition.

[0032] In another preferred embodiment, the blowing agent is a physical blowing agent selected from gases (e.g., hydrocarbons such as butane and pentane) encapsulated in a polymeric shell such as expandable graphite, acrylate copolymers or poly(acrylonitrile), and low-boiling molecules such as water, nitrogen, carbon dioxide, propane, butane and pentane, and is used in an amount of 0.25 to 2.35 wt %, more preferably 0.5 to 2.15 wt %, and even more preferably 0.75 to 1.5 wt %, based on the total weight of the adhesive composition.

[0033] In another preferred embodiment, the blowing agent is a chemical blowing agent such as: 1. Isocyanate 2. Azo compounds (e.g., azobisisobutyronitrile, diisopropyl azodicarboxylate, azodicarbonamide) 3. Hydrazine derivatives [e.g., 4,4'-oxybis(benzenesulfonylhydrazide), p-toluenesulfonylhydrazide] 4. Semicarbazides and sulfonylsemicarbazides [e.g., p-toluenesulfonylsemicarbazide, 4,4'-oxybis(benzenesulfonylsemicarbazide), p,p-oxybisbenzenesulfonylhydrazide] 5. N-nitroso compounds (e.g., dinitrosopentamethylenetetramine) 6. Tetrazoles (e.g., 5-phenyltetrazole, 5-aminotetrazole) 7. Poly(hydrosiloxane) 8. Salts of carbonic and polycarboxylic acids (e.g., sodium bicarbonate) 9. Peroxides (e.g., peroxyhexanoates, peroxydicarbonates); It is used in an amount of 0.25 to 2.35% by weight, more preferably 0.5 to 2.15% by weight, and most preferably 0.75 to 1.5% by weight, based on the total weight of the adhesive composition.

[0034] In another preferred embodiment, the blowing agent is a physical blowing agent, more preferably a hydrocarbon gas encapsulated in a polymer, in particular isopropane, isobutane or isopentane encapsulated in an acrylic acid copolymer or polyacrylonitrile, and is used in an amount of 0.25 to 2.35 wt %, more preferably 0.5 to 2.15 wt %, and even more preferably 0.75 to 1.5 wt %, based on the total weight of the adhesive composition.

[0035] In another preferred embodiment, the foaming agent is a mixture of a physical foaming agent and a chemical foaming agent, for example, a mixture of isooctane, isobutane, or isopentane encapsulated in acrylonitrile and azodicarbonamide, and the physical foaming agent is used in an amount of 0.2 to 1 wt % and the chemical foaming agent is used in an amount of 0.2 to 1 wt % based on the total weight of the mixed adhesive.

[0036] In a particularly preferred embodiment, the blowing agent is 0.4 to 0.8 wt. % isooctane, isobutane, or isopentane encapsulated in acrylonitrile, and 0.3 to 0.7 wt. % azodicarbonamide.

[0037] at least one hardener (C) The adhesive composition of the present invention includes at least one curing agent.

[0038] For one-component adhesives, the curing agent is preferably a latent curing agent, i.e., a curing agent that is activated upon exposure to heat. Examples of latent curing agents include dicyandiamide, hydrazide, and anhydride curing agents. Dicyandiamide is particularly preferred.

[0039] Examples of suitable anhydrides include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyl-5-norbornene-2,3-dicarboxylic anhydride, alkenylsuccinic anhydrides (e.g., dodecenylsuccinic anhydride), and trimellitic anhydride.

[0040] Examples of suitable hydrazides include adipic acid dihydrazide, sebacic acid dihydrazide, dodecane dihydrazide, isophthalic acid dihydrazide, and salicylic acid dihydrazide.

[0041] In the case of two-part adhesives in which the epoxy and hardener components are mixed immediately before use, the hardener may be a latent hardener as described above, or a non-latent hardener. Examples of non-latent hardeners include polyamines, substituted triazines, imidazoles, polycarboxylic acids, polyols, and polyamides.

[0042] Examples of suitable polyamines include aliphatic polyamines, alicyclic polyamines, aromatic polyamines, polyether-based polyamines, polyethyleneimines, and polyamine derivatives.

[0043] Examples of aliphatic polyamines include diethylenetriamine, triethylenetetramine (TETA), triethylenediamine, tetraethylenepentamine, dipropenediamine, diethylaminopropylamine, N-aminoethylpiperazine, menthanediamine, isophoronediamine, and derivatives of these polyamines.

[0044] Examples of polyether-based polyamines include those based on poly(propylene oxide), such as those having the following structure:

[0045] [ka]

[0046] Examples include:

[0047] In a preferred embodiment, the curing agent is a latent curing agent.

[0048] In another preferred embodiment, the curing agent is dicyandiamide.

[0049] In another preferred embodiment, the curing agent is a latent curing agent and is used in an amount of 0.5 to 8 wt %, more preferably 1 to 6 wt %, and particularly preferably 3 to 5 wt %, based on the total weight of the adhesive composition.

[0050] In another preferred embodiment, the curing agent is selected from dicyandiamide, hydrazine and anhydride curing agents and is used in an amount of 0.5 to 8 wt %, more preferably 1 to 6 wt %, particularly preferably 3 to 5 wt %, based on the total weight of the adhesive composition.

[0051] In another preferred embodiment, the curing agent is dicyandiamide, and is used in an amount of 0.5 to 8 wt %, more preferably 1 to 6 wt %, and particularly preferably 3 to 5 wt %, based on the total weight of the adhesive composition.

[0052] In another preferred embodiment, the curing agent is a non-latent curing agent selected from polyamines, polyamides, substituted triazines, imidazoles, polycarboxylic acids, and polyols, and is used in an amount of 0.5 to 50% by weight, more preferably 20 to 50% by weight, and particularly preferably 30 to 50% by weight. In the case of two-component (2K) adhesives, these concentrations refer to the adhesive mixture obtained by mixing the epoxy component and the hardener component.

[0053] Suitable examples of polyamines include aliphatic polyamines, alicyclic polyamines, aromatic polyamines, polyether polyamines, and polyethyleneimines, and are used in amounts of 0.5 to 50% by weight, more preferably 20 to 50% by weight, and particularly preferably 30 to 50% by weight. In the case of two-component (2K) adhesives, these concentrations refer to the adhesive mixture obtained by mixing the epoxy component and the hardener component.

[0054] Examples of aliphatic polyamines include diethylenetriamine, triethylenetetramine (TETA), triethylenediamine, tetraethylenepentamine, dipropenediamine, diethylaminopropylamine, N-aminoethylpiperazine, menthanediamine, and isophoronediamine, and are used at 0.5 to 50% by weight, more preferably 20 to 50% by weight, and particularly preferably 30 to 50% by weight. In the case of two-component (2K) adhesives, these concentrations refer to the adhesive mixture obtained by mixing the epoxy component and the hardener component.

[0055] Examples of polyether-based polyamines include those based on poly(propylene oxide), such as those having the following structure:

[0056] [ka]

[0057] The following are listed: It is used in an amount of 0.5 to 50% by weight, more preferably 20 to 50% by weight, and particularly preferably 30 to 50% by weight. In the case of two-component (2K) adhesives, these concentrations refer to the adhesive mixture obtained by mixing the epoxy component and the hardener component.

[0058] at least one semi-crystalline thermoplastic (D) The adhesive of the present invention comprises one or more semi-crystalline thermoplastic polymers in particulate form.

[0059] In a preferred embodiment, the at least one semi-crystalline thermoplastic polymer has a melting temperature of 140 to 200°C, more preferably 150 to 190°C.

[0060] In a preferred embodiment, the one or more thermoplastic polymers have an average particle size of less than 100 μm.

[0061] In a preferred embodiment, the one or more thermoplastic polymers have an average particle size greater than 5 μm.

[0062] In a preferred embodiment, the one or more thermoplastic polymers have an average particle size of 5 to 100 μm.

[0063] In another preferred embodiment, the one or more thermoplastic polymers are in the form of a powder, in particular a powder having an average particle size of less than 100 μm and a melting temperature of 140-200°C, more preferably 150-190°C.

[0064] Examples of suitable thermoplastics include polyamides, polyesters and copolyetheresters, preferably in powder form.

[0065] In a preferred embodiment, the adhesive composition comprises a polyamide, particularly a long-chain polyamide. Suitable long-chain polyamides include those made from diacids, diamines, or lactams, or aminocarboxylic acids having 6 to 12 carbon atoms, preferably in powder form. Examples include PA66, PA6, PA11, PA12, PA410, PA610, PA1010, PA612, and PA1212, preferably in powder form.

[0066] In a particularly preferred embodiment, the adhesive composition comprises a polyamide selected from PA12, PA11, PA610, PA1010, PA612, PA1212, and mixtures thereof, preferably in powder form, with PA12, preferably in powder form, being particularly preferred.

[0067] In a preferred embodiment, the adhesive composition comprises a copolyetherester, preferably in powder form, in particular a copolyetherester comprising PBT hard segments and PTMEG soft segments, preferably in powder form.

[0068] In a preferred embodiment, the adhesive composition comprises a polyester, preferably in powder form, in particular PBT, preferably in powder form.

[0069] In the case of two-part adhesive compositions (2K) comprising an epoxy component and a hardener component, the thermoplastic may be blended with either or both components.

[0070] When used, the thermoplastic is preferably used in an amount of 5 to 30% by weight, more preferably 7 to 22% by weight, and particularly preferably 8 to 15% by weight, based on the total weight of the adhesive composition.

[0071] In a preferred embodiment, the one or more thermoplastic polymers are in the form of a powder, in particular a powder with an average particle size of less than 100 μm, and are used in an amount of 5 to 30% by weight, more preferably 7 to 22% by weight, particularly preferably 8 to 15% by weight, based on the total weight of the adhesive composition.

[0072] In another preferred embodiment, the one or more thermoplastic polymers have a melting temperature of 140 to 200°C, more preferably 150 to 190°C, and are used in an amount of 5 to 30 wt. %, more preferably 7 to 22 wt. %, particularly preferably 8 to 15 wt. %, based on the total weight of the adhesive composition.

[0073] In another preferred embodiment, the one or more thermoplastic polymers are in the form of a powder, in particular a powder with an average particle size of less than 100 μm, and have a melting temperature of 140 to 200° C., more preferably 150 to 190° C., and are used in an amount of 5 to 30 wt. %, more preferably 7 to 22 wt. %, particularly preferably 8 to 15 wt. %, based on the total weight of the adhesive composition.

[0074] In another preferred embodiment, the thermoplastic is selected from polyamides, polyesters and copolyetheresters, preferably in powder form, and is used in an amount of 5 to 30% by weight, more preferably 7 to 22% by weight, particularly preferably 8 to 15% by weight, based on the total weight of the adhesive composition.

[0075] In another preferred embodiment, the adhesive composition comprises a polyamide, in particular a polyamide made from a diacid, diamine or lactam or an aminocarboxylic acid having 6 to 12 carbon atoms, preferably in powder form, used in an amount of 5 to 30% by weight, more preferably 7 to 22% by weight, particularly preferably 8 to 15% by weight, based on the total weight of the adhesive composition.

[0076] In another preferred embodiment, the thermoplastic is selected from PA66, PA6, PA11, PA12, PA410, PA610, PA1010, PA612, PA1212, preferably in powder form, and is used in an amount of 5 to 30% by weight, more preferably 7 to 22% by weight, particularly preferably 8 to 15% by weight, based on the total weight of the adhesive composition.

[0077] In another preferred embodiment, the thermoplastic is selected from PA12, PA11, PA610, PA1010, PA612, PA1212, and mixtures thereof, preferably in powder form, and is used in an amount of 5 to 30% by weight, more preferably 7 to 22% by weight, particularly preferably 8 to 15% by weight, based on the total weight of the adhesive composition.

[0078] In another preferred embodiment, the thermoplastic is selected from PA12, preferably in powder form, and is used in an amount of 5 to 30% by weight, more preferably 7 to 22% by weight, particularly preferably 8 to 15% by weight, based on the total weight of the adhesive composition.

[0079] In another preferred embodiment, the adhesive composition comprises a copolyetherester, preferably in powder form, used in an amount of 5 to 30% by weight, more preferably 7 to 22% by weight, particularly preferably 8 to 15% by weight, based on the total weight of the adhesive composition.

[0080] In another preferred embodiment, the adhesive composition comprises a copolyetherester selected from those comprising a PBT hard segment and a PTMEG soft segment, preferably in powder form, used in an amount of 5 to 30 wt %, more preferably 7 to 22 wt %, particularly preferably 8 to 15 wt %, based on the total weight of the adhesive composition.

[0081] In another preferred embodiment, the adhesive composition comprises a polyester, preferably in powder form, used in an amount of 5 to 30% by weight, more preferably 7 to 22% by weight, particularly preferably 8 to 15% by weight, based on the total weight of the adhesive composition.

[0082] In another preferred embodiment, the adhesive composition comprises PBT, preferably in powder form, used in an amount of 5 to 30% by weight, more preferably 7 to 22% by weight, particularly preferably 8 to 15% by weight, based on the total weight of the adhesive composition.

[0083] Optional Materials The adhesives of the present invention may contain additional optional materials, such as, for example:

[0084] 1. One or more toughening agents: Toughening agents are elastomeric molecules compatible with the epoxy matrix, imparting impact resistance and resilience to the cured adhesive. Examples include polyurethane-based toughening agents, rubber-based toughening agents, and core-shell rubber toughening agents. In a preferred embodiment, at least one toughening agent is selected from those molecules having terminal functional groups capable of reacting with the epoxy matrix during polymerization. Suitable toughening agents include polyurethane-based toughening agents whose terminal NCO groups are uncapped or capped (e.g., with phenols or polyphenols), and polybutadiene-based toughening agents terminated with amine or diol functionality. In a preferred embodiment, at least one toughening agent is selected from polyurethane toughening agents, particularly those whose terminal NCO groups are capped with phenolic groups, especially cardanol.

[0085] In a particularly preferred embodiment, at least one toughening agent is prepared by reacting a polybutadiene diol, a polyether diol, and a diisocyanate such that the resulting molecule has terminal NCO groups. This type of toughening agent may be used as is or may be capped with a phenol or polyphenol. In a preferred embodiment, the toughening agent is end-capped with cardanol.

[0086] If used, the at least one toughening agent is preferably used at 3 to 25 wt %, more preferably 12 to 18 wt %, based on the total weight of the adhesive.

[0087] In a preferred embodiment, the toughening agent is selected from polyurethane-based toughening agents, rubber-based toughening agents, and core-shell rubber toughening agents and is used in an amount of 3 to 25 wt %, more preferably 12 to 18 wt %, based on the total weight of the adhesive.

[0088] In another preferred embodiment, the at least one toughening agent is selected from those molecules having terminal functional groups capable of reacting with the epoxy matrix during polymerization and is used in an amount of 3 to 25 wt. %, more preferably 12 to 18 wt. %, based on the total weight of the adhesive.

[0089] In another preferred embodiment, at least one toughening agent is a polyurethane-based toughening agent whose terminal NCO groups are uncapped or capped (e.g., with a phenol or polyphenol), or a polybutadiene-based toughening agent terminated with amine or diol functionality, and is used in an amount of 3 to 25 wt. %, more preferably 12 to 18 wt. %, based on the total weight of the adhesive.

[0090] In another preferred embodiment, the at least one toughening agent is selected from polyurethane toughening agents whose terminal NCO groups are capped with phenolic groups, in particular cardanol, and is used in an amount of 3 to 25 wt. %, more preferably 12 to 18 wt. %, based on the total weight of the adhesive.

[0091] In a particularly preferred embodiment, at least one toughening agent is prepared by reacting a polybutadiene diol, a polyether diol and a diisocyanate such that the resulting molecule has terminal NCO groups, and is used in an amount of 3 to 25 wt. %, more preferably 12 to 18 wt. %, based on the total weight of the adhesive.

[0092] In another particularly preferred embodiment, at least one toughening agent is prepared by reacting a polybutadiene diol, a polyether diol, and a diisocyanate such that the resulting molecule has terminal NCO groups, followed by end-capping with cardanol, and is used at 3 to 25 wt. %, more preferably 12 to 18 wt. %, based on the total weight of the adhesive.

[0093] 2. One or More Silane Adhesion Promoters: The adhesive compositions of the present invention may include one or more silane adhesion promoters.

[0094] Preferred silane adhesion promoters have the general formula I:

[0095] [ka]

[0096] where R 1 , R 2 and R 3 are independently selected from C1-C4 alkyl, and R 2 is a divalent C2-C6 alkylene group, and W is glycidyl, amino, or mercapto.

[0097] In a preferred embodiment, in formula I, W is glycidyl.

[0098] In another preferred embodiment, in formula I, R 1 , R 2 and R 3 is methyl and R 2 is propylene.

[0099] In another preferred embodiment, in formula I, R 1 , R 2 and R 3 is methyl and R 2 is propylene and W is glycidyl.

[0100] In a preferred embodiment, the adhesive composition of the present invention comprises gamma-glycidylpropyltrimethoxysilane.

[0101] When used, the silane adhesion promoter is preferably present at 0.05 to 1 wt %, more preferably 0.1 to 0.75 wt %, and most preferably 0.2 to 0.4 wt %, based on the total weight of the adhesive composition.

[0102] Preferably, the at least one silane adhesion promoter has the general formula I:

[0103] [ka]

[0104] where R 1 , R 2 and R 3 are independently selected from C1-C4 alkyl, and R 2 is a divalent C2-C6 alkylene group, and W is glycidyl, amino, or mercapto, and is used in an amount of 0.05 to 1 wt %, more preferably 0.1 to 0.75 wt %, and most preferably 0.2 to 0.4 wt %, based on the total weight of the adhesive composition.

[0105] In a preferred embodiment, in formula I, W is glycidyl and the adhesion promoter is used in an amount of 0.05 to 1 wt. %, more preferably 0.1 to 0.75 wt. %, and most preferably 0.2 to 0.4 wt. %, based on the total weight of the adhesive composition.

[0106] In another preferred embodiment, in formula I, R 1 , R 2 and R 3 is methyl and R2 is propylene, and the adhesion promoter is used in an amount of 0.05 to 1 wt %, more preferably 0.1 to 0.75 wt %, and most preferably 0.2 to 0.4 wt %, based on the total weight of the adhesive composition.

[0107] In another preferred embodiment, in formula I, R 1 , R 2 and R 3 is methyl and R 2 is propylene, W is glycidyl, and the adhesion promoter is used in an amount of 0.05 to 1 wt %, more preferably 0.1 to 0.75 wt %, and more particularly preferably 0.2 to 0.4 wt %, based on the total weight of the adhesive composition.

[0108] In a preferred embodiment, the adhesive composition of the present invention comprises gamma-glycidylpropyltrimethoxysilane, which is used in an amount of 0.05 to 1 wt %, more preferably 0.1 to 0.75 wt %, and even more preferably 0.2 to 0.4 wt %, based on the total weight of the adhesive composition.

[0109] 3. One or More Epoxy Polymerization Catalysts: The adhesive compositions of the present invention optionally include one or more epoxy polymerization catalysts.

[0110] The epoxy polymerization catalyst may be a Lewis base or a Lewis acid. Examples of Lewis bases include tertiary amines and imidazoles.

[0111] Examples of Lewis acids include BF3, ZnCl2, SnCl4, FeCl3, AlCl3, and boron trifluoride complexes.

[0112] In a preferred embodiment, the catalyst is a Lewis base, more preferably a tertiary amine.

[0113] Examples of suitable tertiary amines include 2,4,6-tris(dimethylaminomethyl)phenol, tetramethylguanidine, heptamethylisobiguanide, and N,N-dimethylbenzylamine.

[0114] In another preferred embodiment, the catalyst is 2,4,6-tris(dimethylaminomethyl)phenol, particularly 2,4,6-tris(dimethylaminomethyl)phenol on a novolak support.

[0115] In the case of two-part adhesives that include an epoxy component and a hardener component, the catalyst is combined with the hardener component.

[0116] The catalyst is preferably used in an amount of 0.25 to 1.2% by weight, more preferably 0.5 to 1% by weight, based on the total weight of the adhesive composition.

[0117] In a preferred embodiment, the catalyst is a Lewis base and is used at 0.25 to 1.2 wt %, more preferably 0.5 to 1 wt %, based on the total weight of the adhesive composition.

[0118] In a preferred embodiment, the catalyst is a Lewis acid and is used at 0.25 to 1.2 wt %, more preferably 0.5 to 1 wt %, based on the total weight of the adhesive composition.

[0119] In another preferred embodiment, the catalyst is selected from tertiary amines and imidazoles and is used in an amount of 0.25 to 1.2 wt %, more preferably 0.5 to 1 wt %, based on the total weight of the adhesive composition.

[0120] In another preferred embodiment, the catalyst is selected from BF3, ZnCl2, SnCl4, FeCl3, AlCl3, and boron trifluoride complexes and is used in an amount of 0.25 to 1.2 wt. %, more preferably 0.5 to 1 wt. %, based on the total weight of the adhesive composition.

[0121] In another preferred embodiment, the catalyst is a tertiary amine and is used in an amount of 0.25 to 1.2 wt %, more preferably 0.5 to 1 wt %, based on the total weight of the adhesive composition.

[0122] In another preferred embodiment, the catalyst is selected from 2,4,6-tris(dimethylaminomethyl)phenol, tetramethylguanidine, heptamethylisobiguanide, and N,N-dimethylbenzylamine and is used in an amount of 0.25 to 1.2 wt %, more preferably 0.5 to 1 wt %, based on the total weight of the adhesive composition.

[0123] In another preferred embodiment, the catalyst is 2,4,6-tris(dimethylaminomethyl)phenol, particularly 2,4,6-tris(dimethylaminomethyl)phenol on a novolac support, used at 0.25 to 1.2 wt %, more preferably 0.5 to 1 wt %, based on the total weight of the adhesive composition.

[0124] 4. One or More Thermally Conductive Fillers: The adhesive composition of the present invention optionally contains at least one thermally conductive filler. Suitable thermally conductive fillers have a thermal conductivity of greater than 5 W / m°K, greater than 10 W / m°K, or greater than 15 W / m°K. Examples of thermally conductive fillers include alumina, alumina trihydrate or aluminum trihydroxide (ATH), silicon carbide, boron nitride, diamond, and graphite, or mixtures thereof. Aluminum trihydroxide (ATH) and aluminum oxide are particularly preferred, with ATH being most preferred. Also preferred is a mixture of ATH and alumina, particularly in an ATH:alumina weight ratio of 8 to 15. The thermally conductive filler may or may not be surface-treated.

[0125] In a preferred embodiment, the thermally conductive filler has a broad particle size distribution characterized by a D90 / D50 ratio of greater than or equal to about 3. Particularly preferably, the thermally conductive filler is ATH or aluminum oxide, most preferably ATH, having a broad particle size distribution characterized by a D90 / D50 ratio of greater than or equal to about 3.

[0126] Also preferred are thermally conductive fillers with a bimodal particle size distribution. A bimodal distribution is, for example, when the D90 / D50 ratio is about 3 or greater, more preferably about 5 or greater, and even more preferably about 9 or greater. For example, particles with a D50 of 5-20 microns and a D90 of 70-90 microns, particularly a D50 of 7-9 microns and a D90 of 78-82 microns. Particle size can be determined using laser diffraction. A suitable solvent for ATH is deionized water, preferably containing 1 g / L of a dispersing aid such as NaPO. Aluminum oxide and ATH, especially ATH, with a bimodal distribution are preferred. In a preferred embodiment, the thermally conductive filler is ATH with a D90 / D50 ratio of about 3 or greater, more preferably about 5 or greater, and even more preferably about 9 or greater.

[0127] In a preferred embodiment, the thermally conductive filler is aluminum trihydroxide (ATH) of bimodal distribution, having the following particle size distribution (by laser diffraction, preferably in deionized water containing a dispersing aid such as 1 g / l NaPO x 10 HO): D 10 (microns) 0.5 D 50 (microns) 8 D 90 (microns) 80 It has.

[0128] The thermally conductive filler is preferably present in the final adhesive at a concentration of 10 to 55 wt. %, more preferably 15 to 45 wt. %, and most preferably 20 to 42 wt. %, based on the total weight of the adhesive. For two-component (2K) adhesives, these concentrations refer to the adhesive mixture obtained by mixing the epoxy and hardener components.

[0129] In a preferred embodiment, the thermally conductive filler is aluminum trihydroxide (ATH), which is used in a concentration of 10 to 55 wt. %, more preferably 15 to 45 wt. %, and most preferably 20 to 42 wt. %, based on the total weight of the adhesive. In the case of two-component (2K) adhesives, these concentrations refer to the adhesive mixture obtained by mixing the epoxy and hardener components.

[0130] In another preferred embodiment, the thermally conductive filler is aluminum trihydroxide (ATH) and has the following particle size distribution (by laser diffraction, preferably in deionized water containing a dispersing aid such as 1 g / l NaPO×10 HO): D 10 (microns) 0.5 D 50 (microns) 8 D 90 (microns) 80 and They are used in concentrations of 10 to 55% by weight, more preferably 15 to 45% by weight, and most preferably 20 to 42% by weight, based on the total weight of the adhesive. In the case of two-component (2K) adhesives, these concentrations refer to the adhesive mixture obtained by mixing the epoxy component and the hardener component.

[0131] 5. Non-thermally conductive fillers: The adhesive compositions of the present invention may optionally contain non-thermally conductive fillers such as, for example, calcium carbonate, fumed silica, clay, and the like.

[0132] Manufacturing method For one-part adhesives (1K), simply mix the ingredients together until uniform.

[0133] In a preferred method of manufacture, the epoxy material, silane adhesion promoter (if used), and toughening agent (if used) are mixed together until substantially uniform. The thermally conductive filler and other fillers (if used) are added and mixed. The blowing agent and epoxy polymerization catalyst (if used) are added, followed by the curing agent and mixing until the mixture is homogeneous.

[0134] For two-part adhesives, the epoxy material, silane adhesion promoter (if used), and toughening agent (if used) are mixed together until substantially uniform. The thermally conductive filler and other fillers (if used) are added and mixed. This mixture forms the first component (epoxy component). To form the second component (hardener component), the hardener, epoxy polymerization catalyst (if used), blowing agent, and the thermally conductive filler and other fillers (if used) are mixed together until uniform.

[0135] How to use The present invention also provides a method of bonding substrates, comprising the steps of: (1) providing an expandable adhesive composition, comprising: (A) at least one liquid epoxy resin; (B) at least one blowing agent; (C) at least one hardener; (D) at least one semi-crystalline thermoplastic in particulate form; (2) applying the expandable adhesive composition to a substrate; (3) expanding the expandable adhesive composition; and (4) A step of curing the expandable adhesive composition The present invention provides a method comprising:

[0136] The adhesive may be applied to the substrate by any method including spraying and application through a nozzle, with nozzle application being particularly preferred.

[0137] Expansion is typically achieved by heating, which also initiates curing of the adhesive. Heating may be achieved using any heating method, for example, an oven, IR radiation, or RF radiation.

[0138] Heating is preferably carried out to at least 120° C. Heating may also be carried out to 150, 160, 170, or 180° C. Since curing of epoxy resins is exothermic, once curing has begun, heating may no longer be necessary.

[0139] [Effects of the invention] The adhesives of the present invention exhibit a reduction in peak core temperature at 12 mm compared to adhesives that do not contain a thermally conductive filler and / or compared to adhesives that do not contain a thermoplastic polymer, as measured using the methods set forth in the examples.

[0140] Preferably, the adhesive compositions of the present invention exhibit a peak core temperature at 12 mm of 275°C or less, more preferably 260°C or less, as measured using the method set forth in the Examples.

[0141] The adhesive composition of the present invention preferably exhibits an expansion rate of 130% or more.

[0142] In a preferred embodiment, the adhesive composition of the present invention exhibits a peak core temperature at 12 mm of 275°C or less, more preferably 260°C or less, and an expansion coefficient of 130% or more, as measured using the methods specified in the examples.

[0143] Purpose The adhesives of the present invention are particularly suitable for joining metal substrates and filling cavities in automobile body shops to produce robust composite assemblies.

[0144] Particularly preferred embodiments Particularly preferred embodiments of the present invention are as follows.

[0145] 1. An expandable adhesive composition comprising: (A) at least one liquid epoxy resin; (B) at least one blowing agent; (C) at least one hardener; (D) at least one semi-crystalline thermoplastic in particulate form; 1. An expandable adhesive composition comprising:

[0146] 2. A method for bonding substrates, comprising: (1) providing an expandable adhesive composition, comprising: (A) at least one liquid epoxy resin; (B) at least one blowing agent; (C) at least one hardener; (D) at least one semi-crystalline thermoplastic in particulate form; (2) applying the expandable adhesive composition to a substrate; (3) expanding the expandable adhesive composition; and (4) A step of curing the expandable adhesive composition A method comprising:

[0147] 3. A bonded assembly comprising substrates bonded by an adhesive resulting from the expansion and curing of an expandable adhesive composition, (A) at least one liquid epoxy resin; (B) at least one blowing agent; (C) at least one hardener; (D) at least one semi-crystalline thermoplastic in particulate form; 1. A bonded assembly comprising:

[0148] 4. An expandable adhesive composition comprising: (A) at least one liquid epoxy resin; (B) at least one blowing agent; (C) at least one hardener; (D) at least one semi-crystalline thermoplastic in particulate form; (E) at least one thermally conductive filler 1. An expandable adhesive composition comprising:

[0149] 5. A method for bonding substrates, comprising: (1) providing an expandable adhesive composition, comprising: (A) at least one liquid epoxy resin; (B) at least one blowing agent; (C) at least one hardener; (D) at least one semi-crystalline thermoplastic in particulate form; (E) at least one thermally conductive filler; (2) applying the expandable adhesive composition to a substrate; (3) expanding the expandable adhesive composition; and (4) A step of curing the expandable adhesive composition A method comprising:

[0150] 6. A bonded assembly comprising substrates bonded by an adhesive resulting from the expansion and curing of an expandable adhesive composition, (A) at least one liquid epoxy resin; (B) at least one blowing agent; (C) at least one hardener; (D) at least one semi-crystalline thermoplastic in particulate form; (E) at least one thermally conductive filler 1. A bonded assembly comprising:

[0151] 7. Any one of embodiments 1-6, wherein the liquid epoxy resin is flowable at 25°C and preferably includes any epoxy resin having a viscosity of less than 1,500,000 mPas at 25°C, as measured according to ASTM D-445.

[0152] 8. Any one of embodiments 1-7, wherein the at least one epoxy resin comprises or consists of an epoxy resin having a viscosity of less than 50,000 mPa.s, more preferably less than 20,000 mPa.s, at 25°C, as measured according to ASTM D-445.

[0153] 9. Any one of embodiments 1-8, wherein the epoxy resin comprises or consists of an epoxy resin selected from those formed by the reaction of epichlorohydrin with a bisphenol, particularly bisphenol A, bisphenol AP, bisphenol AF, bisphenol BP, bisphenol B, bisphenol C, bisphenol E, bisphenol F, bisphenol G, bisphenol M, bisphenol S, bisphenol P, bisphenol Z.

[0154] 10. Any one of embodiments 1-9, wherein the epoxy resin comprises or consists of an epoxy resin selected from epoxy resins obtained from the reaction of epichlorohydrin with bisphenol A.

[0155] 11. Any one of embodiments 1-10, wherein the at least one epoxy resin comprises or consists of an epoxy resin obtained from the reaction of epichlorohydrin with bisphenol A and has a viscosity of less than 50,000 mPa.s, more preferably less than 20,000 mPa.s, at 25°C, as measured according to ASTM D-445.

[0156] 12. Any one of embodiments 1-11, wherein the at least one liquid epoxy resin comprises a liquid reaction product of epichlorohydrin and bisphenol A and has an epoxide equivalent weight of 182 to 192 g / eq (as measured according to ASTM D-1652), an epoxide percentage of 22.4 to 23.6% (as measured according to ASTM D-1652), an epoxide group content of 5,200 to 5,500 mmol / kg (as measured according to ASTM D-1652), a viscosity of 11,000 to 14,000 mPas at 25°C (as measured according to ASTM D-445), and a functionality of 2.

[0157] 13. Any one of embodiments 1 to 12, wherein the at least one liquid epoxy resin is used in an amount of 10 to 65 wt. %, more preferably 35 to 60 wt. %, and more particularly preferably 40 to 55 wt. %, based on the total weight of the adhesive composition.

[0158] 14. Any one of embodiments 1 to 13, wherein the at least one epoxy resin comprises or consists of an epoxy resin having a viscosity of less than 1,500,000 mPas at 25°C, as measured according to ASTM D-445, and is used in an amount of 10 to 65 wt. %, more preferably 35 to 60 wt. %, and more particularly preferably 40 to 55 wt. %, based on the total weight of the adhesive composition.

[0159] 15. Any one of embodiments 1-14, wherein the at least one epoxy resin comprises or consists of an epoxy resin having a viscosity of less than 50,000 mPa.s, more preferably less than 20,000 mPa.s, at 25°C, as measured according to ASTM D-445, and is used in an amount of 10 to 65 wt. %, more preferably 35 to 60 wt. %, and more particularly preferably 40 to 55 wt. %, based on the total weight of the adhesive composition.

[0160] 16. Any one of embodiments 1 to 15, wherein the at least one epoxy resin comprises or consists of an epoxy resin formed by reaction of epichlorohydrin with a bisphenol, in particular bisphenol A, bisphenol AP, bisphenol AF, bisphenol BP, bisphenol B, bisphenol C, bisphenol E, bisphenol F, bisphenol G, bisphenol M, bisphenol S, bisphenol P, bisphenol Z, and is used in an amount of 10 to 65 wt. %, more preferably 35 to 60 wt. %, and more particularly preferably 40 to 55 wt. %, based on the total weight of the adhesive composition.

[0161] 17. Any one of embodiments 1 to 16, wherein the at least one epoxy resin comprises or consists of an epoxy resin obtained from the reaction of epichlorohydrin with bisphenol A, and is used in an amount of 10 to 65 wt. %, more preferably 35 to 60 wt. %, and more particularly preferably 40 to 55 wt. %, based on the total weight of the adhesive composition.

[0162] 18. Any one of embodiments 1-17, wherein the at least one epoxy resin comprises or consists of an epoxy resin obtained from the reaction of epichlorohydrin with bisphenol A and has a viscosity of less than 50,000 mPa.s, more preferably less than 20,000 mPa.s, at 25°C, as measured according to ASTM D-445, and is used in an amount of 30-65 wt. %, more preferably 35-60 wt. %, and more particularly preferably 40-55 wt. %, based on the total weight of the adhesive composition.

[0163] 19. Any one of embodiments 1 to 18, wherein the at least one liquid epoxy resin comprises a liquid reaction product of epichlorohydrin and bisphenol A, has an epoxide equivalent weight of 182 to 192 g / eq (as measured according to ASTM D-1652), an epoxide proportion of 22.4 to 23.6% (as measured according to ASTM D-1652), an epoxide group content of 5,200 to 5,500 mmol / kg (as measured according to ASTM D-1652), a viscosity of 11,000 to 14,000 mPas at 25°C (as measured according to ASTM D-445), and a functionality of 2, and is used in an amount of 10 to 65 wt. %, more preferably 35 to 60 wt. %, and more particularly preferably 40 to 55 wt. %, based on the total weight of the adhesive composition.

[0164] 20. Any one of embodiments 1-19, wherein the blowing agent is selected from physical blowing agents, which are low-boiling point molecules or trapped or encapsulated gases, and chemical blowing agents, which are molecules that decompose during curing to release a gas.

[0165] 21. Any one of embodiments 1-20, wherein the blowing agent is selected from expandable graphite and gases (e.g., hydrocarbons such as butane, pentane, etc.) encapsulated in polymeric shells such as poly(acrylonitrile) and acrylate copolymers, and low boiling point molecules such as water, nitrogen, carbon dioxide, propane, butane, and pentane.

[0166] 22. The foaming agent is 1. Isocyanate 2. Azo compounds (e.g., azobisisobutyronitrile, diisopropyl azodicarboxylate, azodicarbonamide) 3. Hydrazine derivatives [e.g., 4,4'-oxybis(benzenesulfonylhydrazide), p-toluenesulfonylhydrazide] 4. Semicarbazides and sulfonylsemicarbazides [e.g., p-toluenesulfonylsemicarbazide, 4,4'-oxybis(benzenesulfonylsemicarbazide), p,p-oxybisbenzenesulfonylhydrazide] 5. N-nitroso compounds (e.g., dinitrosopentamethylenetetramine) 6. Tetrazoles (e.g., 5-phenyltetrazole, 5-aminotetrazole) 7. Poly(hydrosiloxane) 8. Salts of carbonic and polycarboxylic acids (e.g., sodium bicarbonate) 9. Any one of embodiments 1-21, wherein the peroxide (e.g., peroxyhexanoate, peroxydicarbonate) is selected from:

[0167] 23. Any one of embodiments 1-22, wherein the blowing agent is a physical blowing agent, more preferably a hydrocarbon gas encapsulated in a polymer, particularly propane, butane, or pentane encapsulated in a poly(acrylonitrile) and / or acrylate copolymer.

[0168] 24. Any one of embodiments 1-23, wherein the blowing agent is selected from propane, butane, or pentane encapsulated in poly(acrylonitrile) and / or acrylate copolymer.

[0169] 25. Any one of embodiments 1 to 24, wherein the foaming agent is used in an amount of 0.25 to 2.35 wt. %, more preferably 0.5 to 2.15 wt. %, and even more preferably 0.75 to 1.5 wt. %, based on the total weight of the adhesive composition.

[0170] 26. Any one of embodiments 1 to 25, wherein the blowing agent is selected from physical blowing agents, which are low-boiling molecules or trapped or encapsulated gases, and chemical blowing agents, which are molecules that decompose during curing to release a gas, and is used in an amount of 0.25 to 2.35 wt. %, more preferably 0.5 to 2.15 wt. %, and even more preferably 0.75 to 1.5 wt. %, based on the total weight of the adhesive composition.

[0171] 27. Any one of embodiments 1 to 26, wherein the blowing agent is a physical blowing agent selected from expandable graphite, gases (e.g., hydrocarbons such as butane, pentane, etc.) encapsulated in a polymeric shell such as poly(acrylonitrile) and acrylate copolymers, and low-boiling molecules such as water, nitrogen, carbon dioxide, propane, butane, and pentane, and is used in an amount of 0.25 to 2.35 wt. %, more preferably 0.5 to 2.15 wt. %, and more particularly preferably 0.75 to 1.5 wt. %, based on the total weight of the adhesive composition.

[0172] 28. The blowing agent is a chemical blowing agent that: 1. Isocyanate 2. Azo compounds (e.g., azobisisobutyronitrile, diisopropyl azodicarboxylate, azodicarbonamide) 3. Hydrazine derivatives [e.g., 4,4'-oxybis(benzenesulfonylhydrazide), p-toluenesulfonylhydrazide] 4. Semicarbazides and sulfonylsemicarbazides [e.g., p-toluenesulfonylsemicarbazide, 4,4'-oxybis(benzenesulfonylsemicarbazide), p,p-oxybisbenzenesulfonylhydrazide] 5. N-nitroso compounds (e.g., dinitrosopentamethylenetetramine) 6. Tetrazoles (e.g., 5-phenyltetrazole, 5-aminotetrazole) 7. Poly(hydrosiloxane) 8. Salts of carbonic and polycarboxylic acids (e.g., sodium bicarbonate) 9. Peroxides (e.g., peroxyhexanoates, peroxydicarbonates); Any one of embodiments 1 to 27, wherein the adhesive composition is used in an amount of 0.25 to 2.35 wt. %, more preferably 0.5 to 2.15 wt. %, and even more preferably 0.75 to 1.5 wt. %, based on the total weight of the adhesive composition.

[0173] 29. Any one of embodiments 1 to 28, wherein the blowing agent is a hydrocarbon gas encapsulated in a polymer, in particular propane, butane, or pentane encapsulated in poly(acrylonitrile) and / or an acrylate copolymer, used in an amount of 0.25 to 2.35 wt. %, more preferably 0.5 to 2.15 wt. %, and even more preferably 0.75 to 1.5 wt. %, based on the total weight of the adhesive composition.

[0174] 30. Any one of embodiments 1-29, wherein the curing agent is a latent curing agent, i.e., a curing agent that is activated upon exposure to heat.

[0175] 31. Any one of embodiments 1-30, wherein the curing agent is selected from dicyandiamide, hydrazide, and anhydride curing agents.

[0176] 32. Any one of embodiments 1-31, wherein the curing agent is dicyandiamide.

[0177] 33. Any one of embodiments 1-32, wherein the curing agent is selected from phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyl-5-norbornene-2,3-dicarboxylic anhydride, alkenylsuccinic anhydrides (e.g., dodecenylsuccinic anhydride), and trimellitic anhydride.

[0178] 34. Any one of embodiments 1-33, wherein the curing agent is selected from adipic acid dihydrazide, sebacic acid dihydrazide, dodecane dihydrazide, isophthalic acid dihydrazide, and salicylic acid dihydrazide.

[0179] 35. Any one of embodiments 1-34, wherein the adhesive is a two-part adhesive in which an epoxy component and a hardener component are mixed immediately before use, and the hardener is selected from polyamines, substituted triazines, imidazoles, and polycarboxylic acids.

[0180] 36. Embodiment 35, wherein the curing agent is selected from aliphatic polyamines, cycloaliphatic polyamines, aromatic polyamines, polyether-based polyamines, and polyethyleneimines.

[0181] 37. Embodiment 35, wherein the curing agent is selected from diethylenetriamine, triethylenetetramine (TETA), triethylenediamine, tetraethylenepentamine, dipropenediamine, diethylaminopropylamine, N-aminoethylpiperazine, menthanediamine, isophoronediamine.

[0182] 38. The curing agent is based on poly(propylene oxide), for example, the following structure:

[0183] [ka]

[0184] Embodiment 35.

[0185] 39. Any one of embodiments 1-38, wherein the curing agent is a latent curing agent.

[0186] 40. Any one of embodiments 1-39, wherein the curing agent is dicyandiamide.

[0187] 41. Any one of embodiments 1 to 40, wherein the curing agent is a latent curing agent and is used at 0.5 to 8 wt. %, more preferably 1 to 6 wt. %, and particularly preferably 3 to 5 wt. %, based on the total weight of the adhesive composition.

[0188] 42. Any one of embodiments 1 to 41, wherein the curing agent is selected from dicyandiamide, hydrazine, and anhydride curing agents and is used at 0.5 to 8 wt. %, more preferably 1 to 6 wt. %, and particularly preferably 3 to 5 wt. %, based on the total weight of the adhesive composition.

[0189] 43. Any one of embodiments 1 to 42, wherein the curing agent is dicyandiamide and is used at 0.5 to 8 wt. %, more preferably 1 to 6 wt. %, and particularly preferably 3 to 5 wt. %, based on the total weight of the adhesive composition.

[0190] 44. Any one of embodiments 1 to 43, wherein the curing agent is a non-latent curing agent selected from polyamines, polyamides, substituted triazines, imidazoles, polyols, and polycarboxylic acids, and is used in an amount of 0.5 to 50 wt %, more preferably 20 to 50 wt %, and particularly preferably 30 to 50 wt %, based on the total weight of the mixed adhesive composition.

[0191] 45. Any one of embodiments 1 to 44, wherein the curing agent is selected from alicyclic amines, aromatic amines, polyether polyamines, and polyethyleneimines, and is used in an amount of 0.5 to 50 wt %, more preferably 20 to 50 wt %, and particularly preferably 30 to 50 wt %, based on the total weight of the mixed adhesive composition.

[0192] 46. Any one of embodiments 1 to 45, wherein the curing agent is selected from diethylenetriamine, triethylenetetramine (TETA), triethylenediamine, tetraethylenepentamine, dipropenediamine, diethylaminopropylamine, N-aminoethylpiperazine, menthanediamine, and isophoronediamine, and is used in an amount of 0.5 to 50 wt %, more preferably 20 to 50 wt %, and particularly preferably 30 to 50 wt %, based on the total weight of the mixed adhesive composition.

[0193] 47. The curing agent is based on poly(propylene oxide), for example, the following structure:

[0194] [ka]

[0195] are selected from Any one of embodiments 1 to 46, wherein the additive is used in an amount of 0.5 to 50 wt %, more preferably 20 to 50 wt %, and particularly preferably 30 to 50 wt %, based on the total weight of the mixed adhesive composition.

[0196] Any one of the preceding embodiments, additionally comprising a thermally conductive filler selected from those having a thermal conductivity of greater than 48.5 W / m°K, greater than 10 W / m°K, or greater than 15 W / m°K.

[0197] 49. Any one of embodiments 1-48, additionally comprising a thermally conductive filler selected from alumina, alumina trihydrate or aluminum trihydroxide (ATH), silicon carbide, boron nitride, diamond, and graphite, and mixtures thereof. Aluminum trihydroxide (ATH) and aluminum oxide are particularly preferred, with ATH being most preferred.

[0198] 50. Any one of embodiments 1-49, additionally comprising a thermally conductive filler selected from a mixture of ATH and alumina, particularly where the weight ratio of ATH:alumina is 8-15.

[0199] 51. Any one of embodiments 1-50, additionally comprising a thermally conductive filler having a broad particle size distribution characterized by a D90 / D50 ratio of about 3 or greater.

[0200] 52. Any one of embodiments 1-51, additionally comprising a thermally conductive filler that is ATH or aluminum oxide, most preferably ATH, having a broad particle size distribution characterized by a D90 / D50 ratio of about 3 or greater.

[0201] 53. Any one of embodiments 1-52, additionally comprising a thermally conductive filler selected from thermally conductive fillers having a bimodal particle size distribution.

[0202] 54. Any one of embodiments 1-53, additionally comprising a thermally conductive filler, wherein the thermally conductive filler has a D90 / D50 ratio of about 3 or greater, more preferably about 5 or greater, and even more particularly preferably about 9 or greater.

[0203] 55. Any one of embodiments 1-54, additionally comprising a thermally conductive filler selected from aluminum oxide and ATH having a bimodal distribution, and mixtures thereof, especially ATH.

[0204] 56. Any one of embodiments 1-55, additionally comprising a thermally conductive filler that is an ATH having a D90 / D50 ratio of about 3 or greater, more preferably about 5 or greater, and even more particularly preferably about 9 or greater.

[0205] 57. (Preferably by laser diffraction in deionized water containing a dispersing aid such as 1 g / l Na4P2O7×10 H2O) the following particle size distribution: D 10 (microns) 0.5 D 50 (microns) 8 D 90 (microns) 80 57. Any one of the preceding embodiments, additionally comprising a thermally conductive filler which is a bimodal distribution of aluminum trihydroxide (ATH), having:

[0206] 58. Any one of embodiments 1-57, additionally comprising a thermally conductive filler present in the final adhesive at a concentration of 10-55 wt.%, more preferably 15-45 wt.%, and even more particularly preferably 20-42 wt.%, based on the total weight of the adhesive.

[0207] 59. Any one of embodiments 1-58, additionally comprising a thermally conductive filler that is aluminum trihydroxide (ATH), used at a concentration of 10-55 wt.%, more preferably 15-45 wt.%, and even more particularly preferably 20-42 wt.%, based on the total weight of the adhesive.

[0208] 60. (Preferably by laser diffraction in deionized water containing a dispersing aid such as 1 g / l Na4P2O7×10 H2O) the following particle size distribution: D 10 (microns) 0.5 D 50 (microns) 8 D 90 (microns) 80 and additionally comprising a thermally conductive filler which is aluminum trihydroxide (ATH), used at a concentration of 10 to 55 wt. %, more preferably 15 to 45 wt. %, and more particularly preferably 20 to 42 wt. %, based on the total weight of the adhesive.

[0209] 61. Any one of embodiments 1-60, wherein the adhesive composition additionally comprises one or more toughening agents.

[0210] 62. Any one of embodiments 1-61, wherein the adhesive composition additionally comprises one or more toughening agents selected from polyurethane-based toughening agents, rubber-based toughening agents, and core-shell rubber toughening agents.

[0211] 63. Any one of embodiments 1-62, wherein at least one toughening agent is selected from those molecules having a terminal functional group capable of reacting with the epoxy matrix during polymerization.

[0212] 64. Any one of embodiments 1-63, wherein at least one toughening agent is selected from polyurethane-based toughening agents whose terminal NCO groups are uncapped or capped (e.g., with a phenol or polyphenol), and polybutadiene-based toughening agents terminated with amine or diol functionality.

[0213] 65. Any one of embodiments 1-64, wherein the at least one toughening agent is selected from polyurethane toughening agents, particularly those in which the terminal NCO groups are capped with phenolic groups, particularly cardanol.

[0214] 66. Any one of embodiments 1-65, wherein at least one toughening agent is prepared by reacting a polybutadiene diol, a polyether diol, and a diisocyanate such that the resulting molecule has terminal NCO groups.

[0215] 67. Any one of embodiments 1-66, wherein at least one toughening agent is prepared by reacting a polybutadiene diol, a polyether diol, and a diisocyanate, followed by end-capping with a phenol or polyphenol, such that the resulting molecule has terminal NCO groups.

[0216] 68. Any one of embodiments 1-67, wherein at least one toughening agent is prepared by reacting a polybutadiene diol, a polyether diol, and a diisocyanate, followed by end-capping with cardanol, such that the resulting molecule has terminal NCO groups.

[0217] 69. Any one of embodiments 1-68, wherein the at least one toughening agent is used in an amount of 10-25 wt%, more preferably 12-18 wt%, based on the total weight of the adhesive.

[0218] 70. Any one of embodiments 1-69, wherein the toughening agent is selected from polyurethane-based toughening agents, rubber-based toughening agents, and core-shell rubber toughening agents, and is used at 3-25 wt%, more preferably 12-18 wt%, based on the total weight of the adhesive.

[0219] 71. Any one of embodiments 1-70, wherein at least one toughening agent is selected from those molecules having a terminal functional group capable of reacting with the epoxy matrix during polymerization, and is used in an amount of 3-25 wt%, more preferably 12-18 wt%, based on the total weight of the adhesive.

[0220] 72. Any one of embodiments 1-71, wherein at least one toughening agent is a polyurethane-based toughening agent whose terminal NCO groups are uncapped or capped (e.g., with a phenol or polyphenol), or a polybutadiene-based toughening agent terminated with amine or diol functionality, and is used at 3-25 wt%, more preferably 12-18 wt%, based on the total weight of the adhesive.

[0221] 73. Any one of embodiments 1-72, wherein at least one toughening agent is selected from polyurethane toughening agents whose terminal NCO groups are capped with phenolic groups, particularly cardanol, and is used in an amount of 3-25 wt. %, more preferably 12-18 wt. %, based on the total weight of the adhesive.

[0222] 74. Any one of embodiments 1 to 73, wherein the at least one toughening agent is prepared by reacting a polybutadiene diol, a polyether diol, and a diisocyanate such that the resulting molecule has terminal NCO groups, and is used at 3 to 25 wt %, more preferably 12 to 18 wt %, based on the total weight of the adhesive.

[0223] 75. Any one of embodiments 1-74, wherein the at least one toughening agent is prepared by reacting a polybutadiene diol, a polyether diol, and a diisocyanate such that the resulting molecule has terminal NCO groups, followed by end-capping with cardanol, and is used at 3-25 wt%, more preferably 12-18 wt%, based on the total weight of the adhesive.

[0224] 76. Any one of embodiments 1-75, wherein the adhesive composition additionally comprises one or more silane adhesion promoters.

[0225] 77. The adhesive composition comprises a compound of general formula I:

[0226] [ka]

[0227] (In the formula, R 1 , R 2 and R 3 are independently selected from C1-C4 alkyl, and R 2 Any one of the preceding embodiments, additionally comprising one or more silane adhesion promoters of the formula:

[0228] 78. In Formula I, W is glycidyl, embodiment 77.

[0229] 79. In formula I, R 1 , R 2 and R 3 is methyl and R 2 is propylene, embodiment 77 or 78.

[0230] 80. In Formula I, R 1 , R 2 and R 3 is methyl and R 2 Embodiment 77, 78 or 79, wherein is propylene and W is glycidyl.

[0231] 81. Any one of embodiments 1-80, wherein the adhesive composition comprises gamma-glycidylpropyltrimethoxysilane.

[0232] 82. Any one of embodiments 1-81, wherein the adhesive composition additionally comprises a silane adhesion promoter present at 0.05 to 1 wt. %, more preferably 0.1 to 0.75 wt. %, and more particularly preferably 0.2 to 0.4 wt. %, based on the total weight of the adhesive composition.

[0233] 83. The silane adhesion promoter is represented by the general formula I:

[0234] [ka]

[0235] where R 1 , R 2 and R 3 are independently selected from C1-C4 alkyl, and R 2 is a divalent C2-C6 alkylene group, and W is glycidyl, amino, or mercapto, and is used at 0.05 to 1 wt. %, more preferably 0.1 to 0.75 wt. %, and more particularly preferably 0.2 to 0.4 wt. %, based on the total weight of the adhesive composition.

[0236] 84. Embodiment 82 or 83, wherein in Formula I, W is glycidyl and the adhesion promoter is used in an amount of 0.05 to 1 wt. %, more preferably 0.1 to 0.75 wt. %, and more particularly preferably 0.2 to 0.4 wt. %, based on the total weight of the adhesive composition.

[0237] 85. In formula I, R 1 , R 2 and R 3 is methyl and R 2 is propylene, and the adhesion promoter is used in an amount of 0.05 to 1 wt. %, more preferably 0.1 to 0.75 wt. %, and more particularly preferably 0.2 to 0.4 wt. %, based on the total weight of the adhesive composition.

[0238] 86. In formula I, R 1 , R 2 and R 3 is methyl and R 2 Any one of embodiments 82 to 85, wherein R is propylene, W is glycidyl, and the adhesion promoter is used in an amount of 0.05 to 1 wt. %, more preferably 0.1 to 0.75 wt. %, and more particularly preferably 0.2 to 0.4 wt. %, based on the total weight of the adhesive composition.

[0239] 87. Any one of embodiments 82 to 95, wherein the adhesive composition of the present invention comprises gamma-glycidylpropyltrimethoxysilane, used at 0.05 to 1 wt. %, more preferably 0.1 to 0.75 wt. %, and more particularly preferably 0.2 to 0.4 wt. %, based on the total weight of the adhesive composition.

[0240] 88. Any one of embodiments 1-87, wherein the adhesive composition additionally comprises one or more epoxy polymerization catalysts.

[0241] 89. Any one of embodiments 1-88, wherein the adhesive composition additionally comprises one or more epoxy polymerization catalysts selected from Lewis bases and Lewis acids.

[0242] 90. Any one of embodiments 1-89, wherein the adhesive composition additionally comprises one or more epoxy polymerization catalysts selected from tertiary amines and imidazoles.

[0243] 91. Any one of embodiments 1-90, wherein the adhesive composition additionally comprises one or more epoxy polymerization catalysts selected from 2,4,6-tris(dimethylaminomethyl)phenol, tetramethylguanidine, heptamethylisobiguanide, N,N-dimethylbenzylamine.

[0244] 92. Any one of embodiments 1-91, wherein the adhesive composition additionally comprises one or more epoxy polymerization catalysts that are 2,4,6-tris(dimethylaminomethyl)phenol, particularly 2,4,6-tris(dimethylaminomethyl)phenol on a novolac support.

[0245] 93. Any one of embodiments 1-92, wherein the adhesive composition additionally comprises one or more epoxy polymerization catalysts used at 0.25 to 1.2 wt %, more preferably 0.5 to 1 wt %, based on the total weight of the adhesive composition.

[0246] 94. Any one of embodiments 1-93, wherein the adhesive composition additionally comprises one or more epoxy polymerization catalysts that are Lewis bases, used at 0.25 to 1.2 wt %, more preferably 0.5 to 1 wt %, based on the total weight of the adhesive composition.

[0247] 95. Any one of embodiments 1-94, wherein the adhesive composition additionally comprises one or more epoxy polymerization catalysts selected from tertiary amines and imidazoles, used at 0.25 to 1.2 wt %, more preferably 0.5 to 1 wt %, based on the total weight of the adhesive composition.

[0248] 96. Any one of embodiments 1-95, wherein the adhesive composition additionally comprises one or more epoxy polymerization catalysts that are tertiary amines used at 0.25 to 1.2 wt %, more preferably 0.5 to 1 wt %, based on the total weight of the adhesive composition.

[0249] 97. Any one of embodiments 1-96, wherein the adhesive composition additionally comprises one or more epoxy polymerization catalysts selected from 2,4,6-tris(dimethylaminomethyl)phenol, tetramethylguanidine, heptamethylisobiguanide, N,N-dimethylbenzylamine, used at 0.25 to 1.2 wt %, more preferably 0.5 to 1 wt %, based on the total weight of the adhesive composition.

[0250] 98. Any one of embodiments 1-97, wherein the adhesive composition is 2,4,6-tris(dimethylaminomethyl)phenol, particularly 2,4,6-tris(dimethylaminomethyl)phenol on a novolac support, and additionally comprises one or more epoxy polymerization catalysts used at 0.25 to 1.2 wt %, more preferably 0.5 to 1 wt %, based on the total weight of the adhesive composition.

[0251] 99. Any one of embodiments 1-98, wherein the one or more thermoplastic polymers have an average particle size of less than 100 μm.

[0252] 100. Any one of embodiments 1-99, wherein one or more thermoplastic polymers have an average particle size greater than 5 μm.

[0253] 101. Any one of embodiments 1-100, wherein the one or more thermoplastic polymers have an average particle size of 5-100 μm.

[0254] 102. Any one of embodiments 1-101, wherein the at least one thermoplastic polymer is selected from those having a melting temperature of 140-200°C, more preferably 150-190°C.

[0255] 103. Any one of embodiments 1-102, wherein the one or more thermoplastic polymers are selected from polyamides, polyesters, and copolyetheresters, preferably in powder form.

[0256] 104. Any one of embodiments 1-103, wherein the adhesive composition additionally comprises one or more thermoplastic polymers that are polyamides, particularly long-chain polyamides.

[0257] 105. Any one of embodiments 1-104, wherein the one or more thermoplastic polymers are selected from diacids, diamines, or lactams, or long-chain polyamides made from aminocarboxylic acids having 6 to 12 carbon atoms, preferably in powder form.

[0258] 106. Any one of embodiments 1-105, wherein the one or more thermoplastic polymers are selected from PA66, PA6, PA11, PA12, PA410, PA610, PA1010, PA612, PA1212, preferably in powder form.

[0259] 107. Any one of embodiments 1 to 106, wherein the one or more thermoplastic polymers are polyamides selected from PA12, PA11, PA610, PA1010, PA612, PA1212, and mixtures thereof, preferably in powder form, with PA12, preferably in powder form, being particularly preferred.

[0260] 108. Any one of embodiments 1-107, wherein the one or more thermoplastic polymers is a copolyetherester, preferably in powder form, in particular a copolyetherester comprising PBT hard segments and PTMEG soft segments, preferably in powder form.

[0261] 109. Any one of embodiments 1-108, wherein the one or more thermoplastic polymers is a polyester, preferably in powder form, in particular PBT, preferably in powder form.

[0262] 110. Any one of embodiments 1 to 109, wherein the one or more thermoplastic polymers are used in an amount of 5 to 30 wt. %, more preferably 7 to 22 wt. %, and especially preferably 8 to 15 wt. %, based on the total weight of the adhesive composition.

[0263] 111. Any one of embodiments 1 to 110, wherein the one or more thermoplastic polymers are in the form of a powder, in particular a powder having an average particle size of less than 60 μm, and are used in an amount of 5 to 30 wt. %, more preferably 7 to 22 wt. %, and particularly preferably 8 to 15 wt. %, based on the total weight of the adhesive composition.

[0264] 112. Any one of embodiments 1 to 111, wherein the one or more thermoplastic polymers are selected from polyamides, polyesters, and copolyetheresters, preferably in powder form, and are used in an amount of 5 to 30 wt. %, more preferably 7 to 22 wt. %, and particularly preferably 8 to 15 wt. %, based on the total weight of the adhesive composition.

[0265] 113. Any one of embodiments 1 to 112, wherein the one or more thermoplastic polymers are polyamides, in particular polyamides made from diacids, diamines or lactams or aminocarboxylic acids having 6 to 12 carbon atoms, preferably in powder form, used in an amount of 5 to 30 wt. %, more preferably 7 to 22 wt. %, particularly preferably 8 to 15 wt. %, based on the total weight of the adhesive composition.

[0266] 114. Any one of embodiments 1 to 113, wherein the one or more thermoplastic polymers are selected from PA66, PA6, PA11, PA12, PA410, PA610, PA1010, PA612, PA1212, preferably in powder form, and are used in an amount of 5 to 30 wt. %, more preferably 7 to 22 wt. %, and particularly preferably 8 to 15 wt. %, based on the total weight of the adhesive composition.

[0267] 115. Any one of embodiments 1 to 114, wherein the one or more thermoplastic polymers are selected from PA12, PA11, PA610, PA1010, PA612, PA1212, and mixtures thereof, preferably in powder form, and are used in an amount of 5 to 30 wt. %, more preferably 7 to 22 wt. %, and particularly preferably 8 to 15 wt. %, based on the total weight of the adhesive composition.

[0268] 116. Any one of embodiments 1 to 115, wherein the one or more thermoplastic polymers are selected from those of PA12, preferably in powder form, and are used in an amount of 5 to 30 wt. %, more preferably 7 to 22 wt. %, and particularly preferably 8 to 15 wt. %, based on the total weight of the adhesive composition.

[0269] 117. Any one of embodiments 1 to 116, wherein the one or more thermoplastic polymers are copolyetheresters, preferably in powder form, used in an amount of 5 to 30 wt. %, more preferably 7 to 22 wt. %, and particularly preferably 8 to 15 wt. %, based on the total weight of the adhesive composition.

[0270] 118. Any one of embodiments 1 to 117, wherein the one or more thermoplastic polymers are copolyetheresters selected from those comprising PBT hard segments and PTMEG soft segments, preferably in powder form, used in an amount of 5 to 30 wt. %, more preferably 7 to 22 wt. %, and particularly preferably 8 to 15 wt. %, based on the total weight of the adhesive composition.

[0271] 119. Any one of embodiments 1 to 118, wherein the one or more thermoplastic polymers are polyesters, preferably in powder form, used in an amount of 5 to 30 wt. %, more preferably 7 to 22 wt. %, and especially preferably 8 to 15 wt. %, based on the total weight of the adhesive composition.

[0272] 120. Any one of embodiments 1 to 119, wherein the one or more thermoplastic polymers is PBT, preferably in powder form, used in an amount of 5 to 30 wt. %, more preferably 7 to 22 wt. %, and especially preferably 8 to 15 wt. %, based on the total weight of the adhesive composition.

[0273] 121. Any one of embodiments 1-120, wherein the adhesive composition exhibits a reduced peak core temperature at 12 mm compared to an adhesive that does not contain a thermally conductive filler and / or compared to an adhesive that does not contain a thermoplastic polymer, when measured using the method specified in the examples.

[0274] 122. Any one of embodiments 1-121, wherein the adhesive composition exhibits a peak core temperature at 12 mm of 275°C or less, more preferably 260°C or less, when measured using the method specified in the examples.

[0275] 123. Any one of embodiments 1-122, wherein the adhesive composition exhibits an expansion rate of 130% or greater.

[0276] 124. Any one of embodiments 1-123, wherein the adhesive composition exhibits a peak core temperature at 12 mm of 275°C or less, more preferably 260°C or less, and an expansion coefficient of 130% or more, when measured using the method specified in the examples. [Example]

[0277] The materials are listed in Table 1.

[0278] [Table 1]

[0279] [Table 2]

[0280] [Table 3]

[0281] Preparation of adhesive Using the amounts listed in Table 2, comparative and inventive samples were prepared as follows.

[0282] The epoxy resins (Silquest A-187 and DER331) were weighed directly into a 300-long SpeedMixer™ cup, followed by Worflex 7525. The cup was capped and mixed in a Flacktek DAC600 SpeedMixer™ at 2,300 rpm for 1 minute. The mixture was removed from the SpeedMixer™, allowed to cool, and then mixed again using the same program. Next, the thermoplastic polymer powder, red pigment, fumed silica, and alumina trihydrate (if used) were weighed into the cup. The cup was capped and secured with masking tape. The contents were mixed in the Flacktek DAC600 SpeedMixer™ twice for 1 minute at 2,300 rpm, allowing time for the composition to cool between mixes, maintaining a temperature of <65°C. CAB-O-SIL TS720 was added, and the composition was mixed again using the protocol described above. Finally, the epoxy polymerization catalyst (EPCAT 50), Dualite blowing agent, and dicyandiamide were added. The cup was capped and taped. The composition was mixed three times using the protocol described above. Between mixes, a tongue depressor was used to scrape the sample from the cup walls and mixed by hand. The final blend was capped with a lid containing a small hole and then degassed using a FlackTek SpeedMixer, Model DAC 600 VAC. The speed was increased from 900 rpm to 1800 rpm to avoid bumping.

[0283] The volume expansion and peak core temperature achieved at an oven temperature of 180°C with an adhesive layer thickness of 15 mm were measured for each adhesive and the results are summarized in Table 2.

[0284] expansion Volumetric expansion was measured by hydrostatic weighing. For example, a small metal specimen was hung on a balance and weighed in air and in a beaker of water. Adhesive was applied to the specimen, which was then reweighed in air and water. The adhesive was cured at 180°C for 30 minutes, and the resulting specimen, with the expanded adhesive, was hung on the bottom of the balance and reweighed in air and water.

[0285] The results for each individual specimen were calculated using the following equation: Expansion%=((CC-UC)÷(UC-PC))×100% (In the formula, CC = difference in weight of the test piece in air and in water after the product has hardened. UC = difference between uncured specimens in air and water. PC = difference between test piece in air and in water).

[0286] Peak Core Temperature The core peak temperature reached by each adhesive composition during cure was monitored by placing a thermocouple in the center of the adhesive layer sandwiched between two metal plates. The sandwich samples were prepared by dispensing adhesive onto a metal panel covered with Teflon paper (to prevent adhesion). The dispensed adhesive was cut to dimensions of 100 mm x 25.4 mm x 15 mm or 100 mm x 25.4 mm x 12 mm. Metal spacers (15 mm or 12 mm high) were placed on both ends of the resulting adhesive rectangular pillar, and a second Teflon-covered metal panel was placed on top of the assembly. The assembly was secured in place with four metal clips. A thermocouple was then inserted into the center of the adhesive layer through a small hole (approximately 1 mm in diameter) in the center of the bottom plate. A second thermocouple was taped to the metal panel to monitor the metal temperature, and a third thermocouple was attached to the oven rack where the sample was placed to monitor the oven temperature. The final sandwich samples were placed in a preheated oven at 180°C for 30 minutes and the peak core temperature was recorded for each sample.

[0287] Flexural properties of sandwich specimens To evaluate bending stiffness and strength, sandwich composites were fabricated using 6061-T6 aluminum specimens (200 mm long x 25.4 mm wide x 1.6 mm thick) with a 12 mm adhesive layer. The sandwich specimens were cured at 180 °C for 30 min and then subjected to three-point bending tests according to ASTM D7624, Procedure A, using a support spanning 120 mm and a test speed of 5 mm / min.

[0288] [Table 4]

[0289] As shown in Table 2, Comparative Example 1, an expandable structural adhesive composition without thermoplastic powder, achieved a peak core temperature of 302°C. In contrast, when thermoplastic powder was added, peak core temperatures were reduced by 51-75°C. When both a thermoplastic and a thermally conductive filler (ATH) were used, such as IE8, a peak core temperature reduction of 71°C was achieved.

Claims

1. An expandable adhesive composition, (A) at least one liquid epoxy resin; (B) at least one foaming agent; (C) at least one hardening agent; (D) At least one semicrystalline thermoplastic in particulate form An expandable adhesive composition containing [a specific compound / component].

2. An expandable adhesive composition, (A) at least one liquid epoxy resin; (B) at least one foaming agent; (C) at least one hardening agent; (D) At least one semicrystalline thermoplastic in particulate form; (E) at least one thermally conductive filler An expandable adhesive composition containing [a specific compound / component].

3. The adhesive composition according to claim 1, wherein the at least one liquid epoxy resin is an epoxy resin that is flowable at 25°C and has a viscosity of less than 1,500,000 mPas at 25°C as measured according to ASTM D-445.

4. The adhesive composition according to claim 3, wherein the at least one epoxy resin comprises an epoxy resin having a viscosity of less than 50,000 mPa·s at 25°C, as measured according to ASTM D-445.

5. The adhesive composition according to claim 1, wherein the epoxy resin comprises an epoxy resin selected from those formed by the reaction of epichlorohydrin with a bisphenol selected from bisphenol A, bisphenol AP, bisphenol AF, bisphenol BP, bisphenol B, bisphenol C, bisphenol E, bisphenol F, bisphenol G, bisphenol M, bisphenol S, bisphenol P, and bisphenol Z.

6. The adhesive composition according to claim 5, wherein the epoxy resin comprises an epoxy resin selected from epoxy resins obtained from the reaction of epichlorohydrin and bisphenol A.

7. The adhesive composition according to claim 1, wherein the foaming agent is selected from expandable graphite and hydrocarbon gas encapsulated in a polymer shell.

8. The foaming agent is 1. Isocyanates 2. Azo compound 3. Hydrazine derivatives 4. Semicarbazides and sulfonyl semicarbazides 5. N-nitroso compounds 6. Tetrazole 7. Poly(hydrosiloxane) 8. Salts of carbonic acid and polycarboxylic acid 9. The adhesive composition according to claim 1, selected from peroxides.

9. The adhesive composition according to claim 1, wherein the foaming agent is a hydrocarbon gas encapsulated in poly(acrylonitrile) and / or acrylate copolymer.

10. The adhesive composition according to claim 9, wherein the foaming agent is selected from propane, butane, or pentane encapsulated in poly(acrylonitrile) and / or acrylate copolymer.

11. The adhesive composition according to claim 1, wherein the foaming agent is used in an amount of 0.25 to 2.35% by weight, based on the total weight of the adhesive composition.

12. The adhesive composition according to claim 1, wherein the curing agent is a latent curing agent that can be activated when exposed to heat.

13. The adhesive composition according to claim 12, wherein the curing agent is selected from dicyandiamide, hydrazide, and anhydrous curing agents.

14. The adhesive composition according to claim 13, wherein the curing agent is dicyandiamide.

15. The adhesive composition according to claim 1, wherein the curing agent is selected from phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyl-5-norbornene-2,3-dicarboxylic acid anhydride, alkenyl succinic anhydride, and trimellitic anhydride.

16. The adhesive composition according to claim 1, wherein the curing agent is selected from dihydrazide adipic acid, dihydrazide sebacate, dodecane dihydrazide, dihydrazide isophthalic acid, and dihydrazide salicylic acid.

17. The adhesive composition according to claim 1, wherein the adhesive composition comprises an epoxy component and a curing agent component, the two components are mixed immediately before use, and the curing agent is selected from polyamines, substituted triazines, imidazoles, and polycarboxylic acids.

18. The adhesive composition according to claim 17, wherein the curing agent is selected from aliphatic polyamines, alicyclic polyamines, aromatic polyamines, polyether polyamines, and polyethyleneimines.

19. The adhesive composition according to claim 17, wherein the curing agent is selected from diethylenetriamine, triethylenetetramine (TETA), triethylenediamine, tetraethylenepentamine, dipropenediamine, diethylaminopropylamine, N-aminoethylpiperazine, menthanediamine, and isophoronediamine.

20. The curing agent has the following structure: 【Chemistry 1】 The adhesive composition according to claim 17, selected from those based on poly(propylene oxide) having the following properties.

Images