KR102122762B1 - One-component type epoxy-based adhesives composition and articles using thereof - Google Patents

Abstract

The present invention relates to a one-component epoxy-based adhesive composition capable of supplementing brittleness of an epoxy-based adhesive by mixing at least three toughening agents including a phenoxy resin, an epoxy amphiphilic block copolymer, and a urethane resin. will be.
In the present invention, by applying the above-described epoxy-based adhesive as a structural adhesive, specifically an automobile structural adhesive, it is possible to exhibit excellent impact characteristics at low temperature as well as low temperature.

Description

ONE-COMPONENT TYPE EPOXY-BASED ADHESIVES COMPOSITION AND ARTICLES USING THEREOF

The present invention complements the brittleness of the epoxy adhesive by mixing at least three toughening agents comprising a phenoxy resin, an epoxy amphiphilic block copolymer, and a urethane resin, thereby providing excellent impact properties at low and high temperatures. It relates to a one-component epoxy-based structural adhesive composition that can implement and articles using the same.

Epoxy-based adhesives, specifically epoxy-based structural adhesives for bonding of automobile structures, are used for a number of bonding, including metal-metal bonding in frames and other structures in automobiles. Since these adhesives must strongly resist breakage in the event of a vehicle crash, this type of adhesive is called a "collision durable adhesive" or "CDA".

To achieve a balance between the properties required to meet automotive performance requirements, epoxy adhesives are generally formulated with various rubbers and/or “toughening agents”. These toughening agents have blocking functionality that can be released under blocking curing conditions and react with the epoxy resin. The toughening agent is US Patent No. 5,202,390, US Patent No. 5,278,257, WO 2005/118734, US Patent Publication No. 2005/0070634, US Patent Publication No. 2005/0209401, US Patent Publication No. 2006/0276601, EP-A-0 308664, EP-A 1728825, EP-A 1896517, EP-A 1916269, EP-A 1916270, EP-A 1916272 and EP-A-1916285.

Among the prior arts described above, a group showing excellent physical properties is a case where a blocked urethane resin containing phenol, polyphenol, and aminophenol is used as a toughening agent. While the adhesive containing the urethane-based toughening agent exhibits very good impact peel strength at low temperatures, a problem in that impact peel strength is significantly lowered at high temperatures due to the inherent properties of urethane.

Accordingly, there is an urgent need for the development of an epoxy-based structural adhesive that can maintain excellent impact characteristics at high temperatures as well as low temperatures.

The present invention has been devised in order to solve the above-mentioned problems, by mixing at least three toughening agents including a phenoxy resin, an epoxy amphiphilic block copolymer, and a urethane resin, as well as low temperature. Not only that, it is an object of the present invention to provide a one-component epoxy structural structural adhesive composition that exhibits excellent impact peeling strength at high temperature, and at the same time, can provide physical properties (shear strength, T peel strength and impact peeling strength) required as structural adhesives.

In order to achieve the above technical problem, the present invention includes an epoxy resin, at least three toughening agents, and a curing agent, wherein the at least three toughening agents include: phenoxy resin; An epoxy amphiphilic block copolymer containing an epoxy affinity block and an epoxy non-affinity block; And it provides a structural adhesive composition comprising a urethane resin having an isocyanate group capped at least at one end.

According to one embodiment of the present invention, the content ratio of the phenoxy resin and the epoxy amphiphilic block copolymer and the urethane resin may be 1: 0.7 to 2: 1 to 5 weight ratio.

According to an embodiment of the present invention, the phenoxy resin may be a resin formed by reacting bisphenol A with epichlorohydrin.

According to an embodiment of the present invention, the phenoxy resin has a weight average molecular weight (Mw) of 30,000 to 70,000 g/mol, a glass transition temperature (Tg) of 80 to 100°C, and a hydroxyl group (OH) equivalent. 200 to 400 g/eq.

According to one embodiment of the present invention, the epoxy amphiphilic block copolymer, an acrylonitrile-based polymer, ethylene oxide polymer and propylene oxide polymer containing at least one selected from the group consisting of an epoxy affinity block (A); And an epoxy non-affinity block (B) containing an alkylene polymer, and may form micelles in the epoxy resin.

According to one embodiment of the present invention, the epoxy amphiphilic block copolymer has a weight average molecular weight (Mw) of 3,000 to 10,000 g/mol, and may be a double or more multi-block copolymer.

According to an embodiment of the present invention, the urethane resin is a prepolymer having at least one segment selected from the group consisting of polyether, polybutadiene and polyester, and an isocyanate group capped with one of phenol and polyphenol. (prepolymer).

According to one embodiment of the present invention, the urethane resin may have a weight average molecular weight (Mw) of 8,000 to 40,000 g/mol, and a viscosity of 440 to 1280 Pa·s (based on 40° C.).

According to an embodiment of the present invention, the curing agent may have a curing initiation temperature of 80°C or higher.

According to one embodiment of the present invention, the one-component epoxy-based adhesive composition may further include at least one of a curing accelerator, a moisture remover, and a filler.

According to an embodiment of the present invention, the adhesive composition is based on 100 parts by weight of the adhesive composition, epoxy resin 40 to 70 parts by weight; Phenoxy resin 3 to 15 parts by weight; 3 to 13 parts by weight of an epoxy amphiphilic block copolymer; Urethane resin 5 to 30 parts by weight; Curing agent 1.5 to 15 parts by weight; Curing accelerator 0.1 to 4 parts by weight; Moisture removing agent 0.5 to 10 parts by weight; And 2 to 25 parts by weight of a filler.

In addition, the present invention is a first member; A second member adhesively coupled to the first member; And it is disposed between the first member and the second member, and provides an article comprising an adhesive layer cured with the above-described one-component epoxy-based adhesive composition.

According to an embodiment of the present invention, the first member and the second member are the same as or different from each other, and each independently metal, steel plate, wood, film, tile, plastic, glass, resin, ceramic, concrete, carbon material , Fibers and their composite materials.

According to an embodiment of the present invention, one of the first member and the second member is an aluminum (Al) or aluminum alloy (alloy)-based member, the other may be the same or different metal member of the first substrate have.

According to an embodiment of the present invention, the article may satisfy the following physical properties of (i) to (iii) when measured according to ISO 11343 standards: (i) -40°C impact peel strength of 20 N/mm or more And (ii) the impact peeling strength of 20°C is 30 N/mm or more, and (iii) the impact peeling strength of 80°C is 30 N/mm or more.

The one-component epoxy structural structural adhesive composition according to the present invention can maintain excellent physical properties such as impact peeling strength, workability, adhesion, shear strength, and T peeling strength in a wide temperature range of -40°C to 80°C. .

Accordingly, the epoxy adhesive of the present invention can be usefully applied to fasten homogeneous or heterogeneous component materials in a wide range of industries, including automobiles, aircraft, ships, space, civil engineering, and construction.

Hereinafter, the present invention will be described in detail. However, the present invention is not limited only to the following contents, and each component may be variously modified or selectively mixed as necessary. Therefore, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

Structural adhesives are materials used to adhesively bond at least two structural components constituting a structure to each other. These structural adhesives have superior force distribution, faster work speed, and higher economic efficiency than conventional mechanical fastening techniques such as riveting or welding. In particular, in the case of the transportation industry such as automobile, aircraft, or ship, there is an advantage in that weight reduction can be expected by using a structural adhesive rather than using a mechanical fastening technique.

For example, structural adhesives applied to the automotive field are required to withstand impact and not crack in an accident such as a vehicle crash. In addition, excellent properties such as workability, adhesion, and impact peeling strength should be maintained even in a wider temperature range (-40°C to 80°C) than temperatures normally experienced. Conventional epoxy-based automotive structural adhesives have relatively high static strength (i.e., high tensile strength and high adhesive shear strength), while exhibiting poor dynamic strength (i.e., low impact peeling strength), so that the toughening agent to compensate for this is structural It is added as an essential component of the adhesive. However, even if a toughening agent is included, it can only exhibit local impact characteristics at a specific temperature, and it has been difficult to continuously implement excellent impact characteristics in a wide range of temperatures (-40 to 80°C).

Accordingly, the present invention is to provide an epoxy-based structural adhesive that can continuously implement excellent impact properties at low temperatures as well as at low temperatures.

Specifically, in the present invention, in addition to the urethane resin that realizes excellent impact characteristics at low temperatures, at least three toughening agents including a phenoxy resin and an epoxy amphiphilic block copolymer are mixed while controlling them to an optimal ratio. When the above-mentioned three types of toughening agents are used in combination, it has been found that superior impact characteristics can be realized in a wider temperature range than when each of them is used alone. In addition, by adjusting the content of the above-mentioned three toughening agents and the content of other components, the brittleness of the epoxy-based structural adhesive can be supplemented in the present invention, thereby requiring an overall epoxy-based structural adhesive. Physical properties (shear strength, T peel strength and impact peel strength) can be continuously expressed. Accordingly, the epoxy-based adhesive composition of the present invention can be usefully applied as a structural adhesive in a process of fastening parts of the same or different materials in a wide range of industries, including the automotive field, as well as in the aircraft, ship, space, civil, and construction fields. have.

<One-component epoxy-based adhesive composition>

The one-component epoxy-based adhesive composition of the present invention is a structural adhesive capable of forming a structure, and specifically includes an epoxy resin, at least three toughening agents, and a curing agent in an optimal ratio, but the phenoxy resin as the toughening agent, Epoxy amphiphilic block copolymer and urethane resin are mixed. If necessary, it may further include an inorganic filler, a moisture removing agent, a curing accelerator, and at least one additive commonly used in the art.

Hereinafter, the composition of the one-component epoxy-based adhesive composition will be described in detail.

Epoxy resin

In the one-component epoxy-based adhesive composition according to the present invention, an epoxy resin commonly used in the structural adhesive field is used as the main resin.

As the epoxy resin, conventional epoxy resins known in the art can be used. In the present invention, the epoxy resin is produced by the ring-opening reaction of an epoxy compound (monomer), an oligomer or polymer (polymer), and an epoxy group comprising at least one epoxy group in the molecule, preferably at least two epoxy groups. Polymers or oligomers.

Non-limiting examples of usable epoxy resins include bisphenol-type epoxy resins, glycidyl ester-based epoxy resins, glycidylamine-based epoxy resins, phenol novolac-type epoxy resins, cresol-type epoxy resins, aliphatic epoxy resins, and alicyclics Group epoxy resins, polyaromatic epoxy resins, and epoxidized oil-based epoxy resins. Specific examples of the epoxy resin, bisphenol A type epoxy resin, alicyclic epoxy resin, cresol novolac type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, naphthalene type epoxy resin, anthracene epoxy resin, biphenyl Type epoxy resin, tetramethyl biphenyl type epoxy resin, phenol novolak type epoxy resin, bisphenol A novolak type epoxy resin, bisphenol S novolak type epoxy resin, biphenyl noblock type epoxy resin, naphthol novolak type epoxy resin, naphthol Phenolic coaxial novolac type epoxy resin, naphthol corresol coaxial novolac type epoxy resin, (c) aromatic hydrocarbon formaldehyde resin modified phenol resin type epoxy resin, triphenyl methane type epoxy resin, tetraphenylethane type epoxy resin, dicyclopenta And diene type epoxy resins, dicyclopentadiene phenol addition reaction type epoxy resins, phenol aralkyl type epoxy resins, polyfunctional phenol resins, naphthol aralkyl type epoxy resins, or mixtures thereof. Preferably, one or more selected from the group consisting of bisphenol A type epoxy resin, alicyclic epoxy resin, cresol novolac type epoxy resin, dicyclopentadiene type epoxy and biphenyl type epoxy resin can be used.

In the present invention, the content of the epoxy resin is not particularly limited, for example, may be 40 to 70 parts by weight based on the total weight of the epoxy-based adhesive composition (eg, 100 parts by weight), preferably 45 to 65 parts by weight, More preferably, it may be 45 to 60 parts by weight. When the content of the epoxy resin falls within the above-described content range, it may exhibit excellent shear adhesive strength and static strength such as tensile strength.

Phenoxy resin

The one-component epoxy-based adhesive composition according to the present invention is a mixture of at least three toughening agents, one of which is a phenoxy resin.

Phenoxy resin is a thermoplastic polymer, and refers to one having a phenolic functional group at the terminal. In the present invention, the problem of tackiness or brittleness at room temperature can be solved by including the phenoxy resin.

As the phenoxy resin, one known in the art can be used without limitation. Examples of the skeleton of the phenoxy resin include bisphenol A type, bisphenol A/F type, bisphenol F type, bisphenol S type, bisphenol A/S type, cardo-skeleton type, and the like. .

For one embodiment of the present invention, the phenoxy resin may be a bisphenol A-type phenoxy resin obtained by reacting bisphenol A with epichlorohydrin. The bisphenol A-type phenoxy resin has a similar structure to an epoxy resin, and thus has high compatibility, low melt viscosity, and excellent adhesion. In addition, the phenoxy resin is a polyether-based polymer that does not contain an epoxide, and may be modified through a crosslinking reaction with a compound such as isocyanate and amine, including a hydroxyl group as a functional group.

For another embodiment of the present invention, the phenoxy resin has a weight average molecular weight (Mw) of 30,000 to 70,000 g/mol, and preferably 40,000 to 70,000 g/mol. When the weight average molecular weight (Mw) of the phenoxy resin is less than the above-mentioned lower limit, the supportability tends to be weak and the vulnerability tends to be strong. In addition, the phenoxy resin has a glass transition temperature (Tg) of 80 to 100°C, and a hydroxyl group (OH) equivalent of 200 to 400 g/eq. Can be When the glass transition temperature (Tg) of the phenoxy resin is 80 to 100°C, the adhesive strength, softening agent and chemical resistance may be enhanced.

In the present invention, the content of the phenoxy resin is not particularly limited, and for example, may be 3 to 15 parts by weight based on the total weight of the epoxy adhesive composition (eg, 100 parts by weight), preferably 5 to 10 parts by weight Can be. If the content of the phenoxy resin is less than 3 parts by weight, the toughening effect may be remarkably lowered, and when it exceeds 15 parts by weight, a problem that a viscosity becomes very high may occur.

Epoxy amphiphilic block copolymer

In the one-pack epoxy-based adhesive composition according to the present invention, an epoxy amphiphilic block copolymer is applied as a toughening agent.

Epoxy amphiphilic block copolymers are surfactant materials comprising an epoxy affinity block and an epoxy non-affinity (epoxyphobic) block. The epoxy amphiphilic block copolymer spontaneously forms micelles in an epoxy resin by an epoxy affinity block and an epoxy non-affinity block, wherein the core of the micelle is core by an epoxy non-affinity block composed of flexible chains. ) Is formed, it is possible to absorb the shock without lowering the glass transition temperature (Tg).

Specifically, the epoxy amphiphilic block copolymer, an epoxy affinity block containing at least one selected from the group consisting of acrylonitrile-based polymer, ethylene oxide polymer and propylene oxide polymer (A); And an epoxy non-affinity block (B) containing an alkylene polymer. Examples of the epoxy non-affinity block may include polyethylene propylene (PEP), polybutadiene, polyisoprene, polydimethyl siloxane, polyalkyl methyl methacrylate, polyethyl hexyl methacrylate, or combinations thereof. The form of the epoxy amphiphilic block copolymer is not particularly limited, and may be, for example, two or more multi-block copolymers. Specifically, it may be a double block copolymer (eg, A-B) or a triple block copolymer (eg, A-B-A, B-A-B, etc.). In addition, the size and shape of the micelle formed by the epoxy amphiphilic block copolymer is not particularly limited, and may be, for example, nano-scale spherical or worm-like.

For one embodiment of the present invention, the epoxy amphiphilic block copolymer may have a weight average molecular weight (Mw) of 3,000 to 10,000 g/mol, and preferably 5,000 to 9,000 g/mol.

In the present invention, the content of the epoxy amphiphilic block copolymer is not particularly limited, and for example, may be 3 to 13 parts by weight based on the total weight (eg, 100 parts by weight) of the epoxy adhesive composition, preferably 5 to It may be 10 parts by weight. When the content of the epoxy amphiphilic block copolymer is less than 3 parts by weight, micelle formation is insignificant, so that the toughening effect is hardly achieved, and when it exceeds 13 parts by weight, the toughening effect may be rather reduced.

Urethane resin

In the one-component epoxy adhesive composition according to the present invention, the urethane resin is a toughening agent used to realize excellent impact properties at low temperatures.

The urethane resin is a urethane resin known in the art, and at least one having an isocyanate group capped (blocking) at one end may be used without limitation. Here, "capped or blocked" means that the blocking agent is attached to the end of the polymer chain in such a way that the terminal to which it is attached no longer has a reactive group, that is, the capping compound is monofunctional.

Specifically, the urethane resin may be a liquid type having a capped isocyanate group or a polymer having a low melting point. The capped isocyanate group is reacted with a compound (eg, blocking agent) having one or more functional groups capable of reversibly reacting with the isocyanate group to form a blocking moiety. The compound capable of forming the blocking group is not particularly limited, and may be any one of phenol and polyphenol, for example.

The urethane resin according to the present invention may be a prepolymer including an isocyanate-reactive segment and an epoxy group non-reactive blocking segment. Here, the isocyanate-reactive segment may include at least one selected from the group consisting of polyether, polybutadiene and polyester having a weight average molecular weight (Mw) of 300 to 3,000. In addition, the non-reactive segment of the epoxy group is a blocking agent that is not reactive with the epoxy group, and may include an isocyanate group capped with at least one of phenol and polyphenol. The non-reactive segment of the epoxy group is located on at least one end of the urethane resin.

For one embodiment of the present invention, the urethane resin has a weight average molecular weight (Mw) of 8,000 to 40,000 g/mol, and a viscosity of 40 to 1280 Pa·s at 40°C.

In the present invention, the content of the urethane resin is not particularly limited, for example, may be 5 to 30 parts by weight based on the total weight of the epoxy-based adhesive composition (for example, 100 parts by weight), preferably 10 to 25 parts by weight have. If the content of the urethane resin is less than 5 parts by weight, the effect of low-temperature impact strength is insignificant, and thus there is almost no toughening effect. If it exceeds 30 parts by weight, a problem that the toughening effect is rather reduced may occur.

On the other hand, in the present invention, the content ratio of the phenoxy resin and the epoxy amphiphilic block copolymer and the urethane resin mixed as a toughening agent may be 1: 0.7 to 2: 1 to 5 by weight, preferably 1: 0.8 to 1.5: 2 It may be ~4 weight ratio. In addition, the total content of the toughening agent comprising a phenoxy resin, an epoxy amphiphilic block copolymer and a urethane resin may be 20 to 50 parts by weight with respect to the total weight (for example, 100 parts by weight) of the epoxy adhesive composition, preferably It may be 20 to 45 parts by weight, more preferably 25 to 40 parts by weight.

Hardener

In the one-component epoxy adhesive composition according to the present invention, the curing agent is a component that reacts with the main resin, an epoxy resin, and advances the curing of the composition.

The curing agent may be used without limitation, a conventional curing agent known in the art. Specifically, the curing agent is reactive with an epoxy resin, and a curing initiation temperature of 80°C or higher can be used. Preferably, a curing initiation temperature of 120°C or higher, more preferably 140°C or higher can be used. The curing agent rapidly cures upon heating above the curing initiation temperature, but it is appropriate to use any catalyst(s) alone or in combination to allow curing very slowly at room temperature (about 22° C.) and at temperatures up to at least 50° C. In one example, the curing agent is a nitrogen-containing compound (eg, amine and derivatives thereof); Oxygen-containing compounds (eg, carboxylic acid-terminated polyesters), anhydrides, phenol-formaldehyde resins, amino-formaldehyde resins, phenols, bisphenol A and cresol novolacs, phenol-terminated epoxy resins; Sulfur-containing compounds (eg, polysulfide, polymercaptan); Catalytic curing agents (eg, tertiary amines, Lewis acids, Lewis bases) or combinations thereof can be used.

Non-limiting examples of curing agents that can be used include boron trichloride/amine and boron trifluoride/amine complexes, dicyandiamide, melamine, diallyl melamine; Guanamines such as acetoguanamine and benzoguanamine; Aminotriazoles such as 3-amino-1,2,4-triazole; Hydrazides such as adipic dihydrazide, stearic acid dihydrazide, isophthalic acid dihydrazide, semicarbazide, and cyanoacetamide; Aromatic polyamines such as diaminodiphenylsulfone. The above-mentioned components may be used alone, or two or more of them may be used in combination. In particular, it is preferable to use at least one selected from the group consisting of dicyandiamide, isophthalic dihydrazide, adipic dihydrazide, and 4,4'-diaminodiphenylsulfone.

The curing agent may be used in an amount sufficient to cure the epoxy adhesive composition. In general, it is used by adjusting the content capable of consuming at least 80% or more of the epoxy groups present in the adhesive composition, and an excessive amount is unnecessary than is necessary to consume all epoxy groups. In the present invention, the content of the curing agent may be, for example, 1.5 to 15 parts by weight based on the total weight (eg, 100 parts by weight) of the epoxy adhesive composition, preferably 2.5 to 10 parts by weight, more preferably 3 It may be from 8 parts by weight.

Curing accelerator

The one-component epoxy-based adhesive composition according to the present invention may further include a curing accelerator known in the art as necessary.

The curing accelerator is a thermally activatable catalyst, and solid or liquid tertiary amine compounds having a boiling point of 130° C. or higher can be used without limitation. In one example, urea-based compounds; Aminophenol; And various aliphatic urea compounds such as C ₁ -C ₁₂ alkylene imidazole or N-arylimidazole.

Non-limiting examples of curing accelerators that can be used include p-chlorophenyl-N,N-dimethylurea, 3-phenyl-1,1-dimethylurea, 3,4-dichlorophenyl-N,N-di Methylurea, N-(3-chloro-4-methylphenyl)-N',N'-dimethylurea, benzyldimethylamine; 2,4,6-tris(dimethylaminomethyl)phenol, piperidine, 2-ethyl-2-methylimidazole, N-butylimidazole, 6-caprolactam, and the like. Preferably, it may be an aminophenol compound such as 2,4,6-tris(dimethylaminomethyl)phenol. The above-mentioned components may be used alone or in combination of two or more.

The curing accelerator may be mixed with at least one other catalyst, preferably a heat-activatable catalyst. The catalyst that can be used in this way may include various amine compounds (which are blocked with a novolac resin and other blocking groups), and specific examples include blocked 1-(2-(2-hydroxylbenzamino)ethyl)- 2-(2-hydroxyphenyl-2-imidazoline).

In the present invention, the content of the curing accelerator (eg, a heat-activatable catalyst) is not particularly limited, and may be, for example, 0.1 to 4 parts by weight based on the total weight (eg, 100 parts by weight) of the epoxy adhesive composition, preferably It may be 0.5 to 1.5 parts by weight, more preferably 0.5 to 1.0 parts by weight.

Filler

The one-component epoxy-based adhesive composition according to the present invention may further include a filler known in the art as necessary.

The filler may be used without particular limitation as long as it is a material that does not react with other components included in the above-described epoxy-based adhesive composition, and examples thereof include inorganic fillers, organic fillers, or composite forms thereof.

The filler preferably improves the rheology of the adhesive, reduces the total cost per unit weight, absorbs moisture or oil from the adhesive or from the substrate to which it is applied, and/or cohesive failure. At least one or more functions, such as to promote the can be performed in combination.

Non-limiting examples of fillers that can be used include calcium carbonate, talc, carbon black, textile fibers, glass particles or fibers, aramid pulp, boron fibers, carbon fibers, inorganic silicates, mica, powder crystals, hydrated aluminum oxide, bentotite , Wollastonite, kaolin, silica, fumed silica, silica airgel, silica nitride, alumina, aluminum nitride, boron nitride, talc, carbon, polyurea compounds, polyamide compounds or metal powders. The above-mentioned components may be used alone or in combination of two or more. For example, the metal powder may include at least one of materials such as aluminum powder or iron powder.

The average particle diameter of the filler is not particularly limited, and can be appropriately adjusted within a range known in the art. In one example, the average particle diameter of the inorganic filler may be 1 to 100 μm. In addition, the shape of the inorganic filler is not particularly limited, and may be, for example, spherical, square, plate-shaped, needle-shaped, or amorphous.

In the present invention, the content of the filler is not particularly limited, and for example, may be 2 to 25 parts by weight based on the total weight of the epoxy adhesive composition (eg, 100 parts by weight), specifically 5 to 20 parts by weight.

Moisture remover

The one-component epoxy-based adhesive composition according to the present invention may further include a water remover known in the art as necessary.

The moisture remover is a material that physically or chemically bonds with free water present in the thermosetting structural adhesive composition, specifically, does not release bound water until heated to a temperature of 160°C or higher, preferably 200°C or higher. By reducing the water content. The moisture removing agent can be confirmed by significantly extending the opening time of the above-described epoxy-based structural adhesive at a temperature of less than 80°C.

Non-limiting examples of moisture removers that can be used include calcium oxide, magnesium oxide, phosphorus pentoxide, various molecular sieves, or mixtures thereof. It is preferably calcium oxide, and such calcium oxide may be provided in the form of fine particles, specifically, less than 100 μm in diameter.

In the present invention, the content of the water removing agent is not particularly limited, and for example, may be 0.5 to 10 parts by weight based on the total weight (eg, 100 parts by weight) of the epoxy adhesive composition, preferably 2 to 5 parts by weight have.

additive

The one-component epoxy-based adhesive composition of the present invention may further include additives commonly used in the art within a range that does not impair the inherent properties of the composition.

Non-limiting examples of additives that can be used include rheology improvers, rheology modifiers, pigments, dyes, diluents, plasticizers, extenders, flame retardants, thixotropes, expanders, flow control agents, adhesion promoters, thermoplastic powders, core-shells Rubbers, dimerized fatty acids, antioxidants, or combinations thereof. The content of each additive may be appropriately added within a content range known in the art, and for example, may be 0.1 to 5 parts by weight, respectively, based on the total weight (eg, 100 parts by weight) of the epoxy adhesive composition. . In addition, the total content of the additive may be 0.1 to 25 parts by weight based on the total weight of the epoxy adhesive composition, but is not particularly limited thereto.

In the present invention, in order to further improve flame retardancy, a conventional flame retardant may be included. Non-limiting examples of flame retardants that can be used include metal hydroxides [eg, alumina trihydrate], phosphorus and nitrogen-containing organic compounds [eg, resorcinol diphosphate, phosphate, phenoxyphosphazene), Melamine or melamine derivatives (eg, melamine cyanurate, phenolic melamine resin), zinc borate or mixtures thereof. Examples of the metal hydroxide include a hydroxide of a metal selected from magnesium, calcium, strontium, barium, boron, aluminum, and gallium.

In addition, in the present invention, the rate and selectivity of curing can be controlled by incorporating a monomeric or oligomeric addition polymerizable ethylenically unsaturated material into the structural adhesive. Preferably, the ethylenically unsaturated material has a molecular weight of less than about 1500. Examples of such ethylenically unsaturated materials may be acrylate or methacrylate compounds, unsaturated polyesters, vinyl ester resins, or epoxy adducts of unsaturated polyester resins. The structural adhesive composition of the present invention may contain a free radical initiator, which is a source of free radicals, to polymerize the ethylenically unsaturated material. Incorporation of such an ethylenically unsaturated material can be achieved through the selective polymerization of an ethylenically unsaturated group. This provides the possibility to perform partial curing.

Intumescent agents include both physical and chemical type materials known in the art. The adhesive may also contain thermoplastic powders, for example polyvinyl butyral or polyester polyols.

The diluent may use a miscible solvent used in the adhesive composition in the art, for example, ketone, ether, acetate, aromatic hydrocarbon, cyclohexanone, dimethylformamide, glycol ether, or a combination thereof.

The one-component epoxy adhesive composition of the present invention configured as described above is applicable to all uses in which an epoxy adhesive is used, and for example, it is used as a structural adhesive for forming a structure by adhesively bonding at least two parts to be fastened. Can be. Specifically, it is preferably used to manufacture structures for the electronic, architectural, aircraft and automotive industries, and parts made of various materials, such as wood, metal, coated metal, aluminum, various plastics and filled plastic substrates, fiberglass, etc. Can be used to bond them.

In particular, the one-component epoxy adhesive composition of the present invention can continuously maintain the overall properties of the automotive structural adhesive in the temperature range of -40°C to 80°C, so that the automotive parts are adhered to each other or the automotive parts are adhered to the vehicle. It can be usefully applied as a structural adhesive in the automotive field.

<Goods>

The present invention also provides articles having an adhesive layer cured using the one-component epoxy-based adhesive composition described above, preferably articles in the automotive field.

Specifically, the article includes a first member; A second member adhesively coupled to the first member; And it is disposed between the first member and the second member, and includes an adhesive layer formed from the above-described one-component epoxy-based adhesive composition.

The first member and the second member are not particularly limited as long as they are combined and fastened by an adhesive layer, and may be the same or different from each other. For example, the first member and the second member may be selected from the group consisting of metal, steel plate, wood, film, tile, plastic, glass, resin, ceramic, concrete, carbon material, fiber, and composite materials thereof, respectively. . Preferably, it may be a component material in the automotive field, specifically, steel, coated steel, galvanized steel, aluminum, coated aluminum, plastic, filled plastic material, composite material.

In particular, the one-part epoxy adhesive according to the present invention is preferably used as a structural adhesive for bonding the same or different automotive frame components. Accordingly, each of the first member and the second member may be a frame component of a general metal material, plastic material, and/or composite material used in the automobile field. Among them, the metal material may be a common metal used for automobile materials, home appliances, building materials, and industrial applications, for example, cold rolled steel (CR), zinc hot dipping steel (GI), electro-zinc steel (EGI) ), alloy-plate steel (GA), copper sheet or tin-plate steel, hot-dip galvanized steel sheet, hot-dip galvanized steel sheet, electro-galvanized steel sheet, hot-dip aluminum-zinc alloy galvanized steel sheet, metal material of zinc and aluminum, zinc Plated metal or aluminum plate. More specifically, it may be cold rolled steel, galvanized metal or aluminum.

In one embodiment of the present invention, one of the first member and the second member is an aluminum (Al) or aluminum alloy (alloy)-based member, the other may be the same or different metal member of the first member have. Preferably, both the first member and the second member may be aluminum (Al) or aluminum alloy-based materials. Here, aluminum means a pure aluminum metal or any alloy containing 80% by weight or more of aluminum.

The article according to the present invention can be produced by conventional methods known in the art, except for using the one-component epoxy-based adhesive composition described above. For example, after applying the epoxy-based adhesive composition to at least one of the first member and the second member, it may be prepared by curing to form and bond the adhesive layer.

The method of applying the epoxy-based adhesive composition is not particularly limited as long as it is a method known in the art, and for example, powder-coating, spray-coating, and the like may be applied. Specifically, the epoxy-based adhesive composition of the present invention may be applied according to any technique known in the art, and may be applied cold or warm as needed. For example, it can be applied by extruding from a robot onto a substrate in the form of a bead, and a mechanical application means such as a caulking gun or any other application means can be applied. It may also be applied by using a jet injection method, for example, a streaming method or a swirl technique. The epoxy-based adhesive composition may be applied to one of the first member and the second member, or may be applied to both of them, and is disposed such that an adhesive is positioned between the first member and the second member.

Subsequently, the epoxy adhesive composition may be cured by heating the curing agent to a curing initiation temperature or higher. At this time, the heating conditions are not particularly limited, and may be appropriately changed according to conditions such as width and thickness of the first and second members to be used, process line speed, and the like. The curing initiation temperature may be approximately 80°C to 220°C, preferably about 140°C to 180°C, more preferably 150 to 170°C. Particularly, in the present invention, when curing at a temperature of about 170° C. or less, specifically 140 to 170° C., preferably 150 to 170° C., there is an advantage of exerting excellent impact peel strength and stress durability. The aforementioned curing process may use a heat source, a radiation source, or a combination of energy sources known in the art.

By the above-described method, the adhesive layer (eg, structural adhesive portion) is formed in contact with them between the first member and the second member. At this time, the first member and the second member may constitute the entire vehicle frame assembly or may form at least a part. The first member and the second member may be coated by a coating requiring calcination curing, and the structural adhesive may be cured simultaneously with the calcination curing of the aforementioned coating. Also, the first member (aluminum member) and the second member (metal member) may be welded before the epoxy structural adhesive is cured.

According to one embodiment of the present invention, the article may satisfy the properties of (i) to (iii) below when measured according to the ISO 11343 standard. (i) -40℃ impact peel strength is 20 N/mm or more, (ii) 20℃ impact peel strength is 30 N/mm or more, and (iii) 80℃ impact peel strength is 30 N/mm or more. It can also exhibit excellent shear strength and T-peel strength.

Hereinafter, the present invention will be described in more detail through examples. However, the following examples are only to aid the understanding of the present invention, and the scope of the present invention is not limited to the examples in any sense.

<Examples 1-2. Preparation of one-component epoxy adhesive composition>

[Example 1]

The epoxy adhesive composition was prepared by blending the components and composition ratios shown in Tables 1 and 2 below.

Specifically, after dissolving 6.1% by weight of phenoxy resin in 55% by weight of bisphenol A-type epoxy resin, 20% by weight of urethane toughening agent was quantified in a reactor and stirred for 10 minutes. Thereafter, 7.4% by weight of a block copolymer, 3% by weight of calcium oxide, and 3% by weight of hydrophobic fumed silica were added to the reactor, followed by stirring under vacuum for 30 minutes. Thereafter, 4.8% by weight of the curing agent, and 0.7% by weight of the heat-activatable catalyst were added, followed by vacuum stirring for 30 minutes to prepare a one-part epoxy adhesive composition of Example 1. In Table 2, the unit of use of each composition is% by weight.

[Example 2]

A one-component epoxy adhesive composition of Example 2 was prepared by performing the same method as in Example 1, except that each component was blended according to the composition shown in Table 2 below.

Component division Detailed specification Epoxy resin A Bisphenol A type epoxy resin (Kukdo Chemical / YD-128)
-Epoxy equivalent (EEW): 184-190 Toughening agent B-1 Phenoxy resin (Gavriel/PKHH)
-Mw: 52000, hydroxyl equivalent: 280 g/eq, Tg: 92°C B-2 Epoxy amphiphilic block copolymer (DOW / FORTEGRA ^TM 100)
-Viscosity: 3600 cP B-3 Urethane resin (HUNTSMAN / Flexibilizer DY 965)
-Hydroxyl equivalent: 558-667 g/eq, viscosity: 440-1280 Pa s (40℃) Hardener C Evonik / Dicyanex ^®® 1400F Curing accelerator D Evonik / Amicure ^®® UR-D Moisture remover E Calcium oxide (Yooyoung Materials / UNI-OX) Filler F Fumed silica (Evonik / aerosil ^®® R202)

division Example Comparative example One 2 One 2 3 Epoxy resin A 55.0 52.5 62.7 61.1 59.0 Toughening agent B-1 6.1 7.3 - 6.7 - B-2 7.4 8.9 - - 9.0 B-3 20.0 20.0 25.0 20.0 20.0 Hardener C 4.8 4.6 5.5 5.4 5.2 catalyst D 0.7 0.7 0.8 0.8 0.8 Moisture remover E 3.0 3.0 3.0 3.0 3.0 Filler F 3.0 3.0 3.0 3.0 3.0 Total (% by weight) 100 100 100 100 100

[ Comparative example 1~3]

The one-component epoxy adhesive compositions of Comparative Examples 1 to 3 were prepared by performing the same method as in Example 1, except that each component was blended according to the composition shown in Table 2.

[ Experimental Example . Property evaluation]

Using the epoxy adhesive compositions prepared in Examples 1 to 2 and Comparative Examples 1 to 3, physical properties were measured in the following manner, and the results are shown in Table 3 below.

(1) Evaluation of single lap shear strength (Mpa)

In the shear strength test, a cold rolled steel sheet (CR) having a size of 100 mm×25 mm×1.6T was used after removing contamination using ethanol. After applying a 12.5 mm adhesive to one surface of the steel sheet, a small amount of microbeads was used to maintain a constant adhesive thickness thereon. And after the other specimens were covered and fixed, they were cured under conditions of 180°C and 20 minutes. After curing, the shear strength of the test piece cooled to 23° C. was measured using a universal material tester. At this time, the test conditions were applied in a direction of 180 로 at a tensile speed of 5 mm/min.

(2) T-peel strength (N/25 mm) evaluation

In the T-peel strength test, a steel plate having a size of 150 mm × 25 mm × 0.8T was bent at a right angle, and after bending, the length of each surface was set to be 70 mm and 80 mm. An adhesive was applied to the 80 mm portion and a constant adhesive thickness was maintained using microbeads. And after the other specimens were covered and fixed, they were cured under conditions of 180°C and 20 minutes. After curing, the shear strength of the test piece cooled to 23° C. was measured using a universal material tester. At this time, the test conditions were applied in a direction of 180ㅀ at a tensile speed of 50 mm/min.

(3) Impact peel strength (N/25 mm) evaluation

The impact peel strength test was conducted according to the ISO 11343 standard. The size of the test piece was 90 mm × 20 mm × 1.6T, and the size of one surface to which the adhesive was applied was 30 × 20 mm. After removing the contaminants on one side of the test piece using ethanol, an adhesive was applied. The thickness of the adhesive was kept constant using microbeads, and another specimen was fixed over it, and then cured under conditions of 180°C and 20 minutes. After curing, after stabilization for 1 hour or more at each test temperature condition, shear strength was measured using an impact strength tester suitable for the ISO 11343 standard. At this time, the test conditions were applied at a speed of 2 m/sec.

Shear strength
(MPa) T Peel strength
(N/25mm) Impact peel strength (N/mm) Low temperature (-40℃) Room temperature (20℃) High temperature (80℃) Example 1 36.5 390 25.1 39.3 36.7 Example 2 37.6 374 21.7 35.3 38.3 Comparative Example 1 31.3 387 31.1 37.5 - Comparative Example 2 35.9 371 22.4 32.5 26.9 Comparative Example 3 32.8 401 - 29.0 14.5

As shown in Table 3, in Comparative Examples 1 to 3 without three toughening agents, it was found that excellent impact peel strength was realized only in a specific temperature range. On the other hand, in Examples 1 and 2 containing at least three toughening agents, it can be seen that not only shows excellent shear strength and T peel strength, but also exhibits excellent impact peel strength in the entire temperature range of -40°C to 80°C. there was.

Through the above-described results, it was confirmed that the one-component epoxy-based adhesive composition according to the present invention can be usefully applied as a structural adhesive for bonding an automobile structure.

Claims (16)

An epoxy resin, at least three toughening agents, and a curing agent,
The at least three toughening agents,
Phenoxy resin having a weight average molecular weight (Mw) of 30,000 to 70,000 g/mol, a glass transition temperature (Tg) of 80 to 100°C, and a hydroxyl group (OH) equivalent of 200 to 400 g/eq.;
An epoxy amphiphilic block copolymer containing an epoxy affinity block and an epoxy non-affinity block; And
A urethane resin having an isocyanate group capped at least at one end thereof;
It includes,
The content ratio of the phenoxy resin and the epoxy amphiphilic block copolymer and the urethane resin is 1: 0.7 to 2: 1 to 5 weight ratio, a one-pack epoxy adhesive composition.
delete According to claim 1,
The phenoxy resin is a one-component epoxy adhesive composition formed by reacting bisphenol A and epichlorohydrin. delete According to claim 1,
The epoxy amphiphilic block copolymer,
An epoxy affinity block (A) containing at least one selected from the group consisting of acrylonitrile-based polymers, ethylene oxide polymers and propylene oxide polymers; And
Contains an epoxy non-affinity block (B) containing an alkylene polymer,
A one-component epoxy adhesive composition that forms micelles in an epoxy resin. According to claim 1,
The epoxy amphiphilic block copolymer has a weight-average molecular weight (Mw) of 3,000 to 10,000 g/mol, and is a two or more multi-block copolymer, one-pack epoxy-based adhesive composition. According to claim 1,
The urethane resin,
At least one segment selected from the group consisting of polyethers, polybutadienes and polyesters,
A one-component epoxy adhesive composition that is a prepolymer having an isocyanate group capped with either phenol or polyphenol. According to claim 1,
The urethane resin has a weight average molecular weight (Mw) of 8,000 to 40,000 g/mol, and a viscosity of 440 to 1280 Pa·s (based on 40° C.), a one-pack epoxy adhesive composition. According to claim 1,
The curing agent is a one-component epoxy adhesive composition having a curing initiation temperature of 80°C or higher. According to claim 1,
A one-component epoxy adhesive composition further comprising at least one of a curing accelerator, a moisture remover, and a filler. The method of claim 10,
The adhesive composition, based on 100 parts by weight of the adhesive composition,
40 to 70 parts by weight of an epoxy resin;
Phenoxy resin 3 to 15 parts by weight;
3 to 13 parts by weight of an epoxy amphiphilic block copolymer;
Urethane resin 5 to 30 parts by weight;
Curing agent 1.5 to 15 parts by weight;
Curing accelerator 0.1 to 4 parts by weight;
Moisture removing agent 0.5 to 10 parts by weight; And
Filler 2 to 25 parts by weight
One-component epoxy-based adhesive composition comprising a. According to claim 1,
As rheology improvers, rheology modifiers, pigments, dyes, diluents, plasticizers, extenders, flame retardants, thixotropes, expanders, flow control agents, adhesion promoters, thermoplastic powders, core-shell rubbers, dimerized fatty acids, and antioxidants A one-component epoxy-based adhesive composition further comprising at least one additive selected from the group consisting of. A first member;
A second member adhesively coupled to the first member; And
An adhesive layer disposed between the first member and the second member, and curing the one-component epoxy-based adhesive composition according to any one of claims 1, 3, 5 to 12
The article containing. The method of claim 13,
The first member and the second member are the same or different from each other, and each independently made of metal, steel plate, wood, film, tile, plastic, glass, resin, ceramic, concrete, carbon material, fiber, and composite materials thereof Goods selected from the military. The method of claim 13,
One of the first member and the second member is an aluminum (Al) or aluminum alloy (alloy)-based member, the other is the same or different metal member of the first member. The method of claim 13,
When measured according to the ISO 11343 standard, articles satisfying the following physical properties of (i) to (iii):
(i) -40℃ impact peel strength is 20 N/mm or more,
(ii) the impact peel strength at 20°C is 30 N/mm or more,
(iii) 80℃ impact peel strength is over 30 N/mm.