Epoxy resin adhesive composition and its cured product

Abstract

To provide an epoxy resin adhesive composition that demonstrates superior adhesion after a test in a high-temperature, high-humidity environment at 85°C×85%RH.SOLUTION: An epoxy resin adhesive composition comprises the following components (A)-(D). Components (A): an epoxy resin, (B): a curing agent reactable with the epoxy resin, (C): an alkali metal hydroxide and (D): water.SELECTED DRAWING: None

Description

Technical Field

[0006] , , , ,

[0001] The present invention relates to an epoxy resin adhesive composition and a cured product thereof.

Background Art

[0002] Conventionally, epoxy resin adhesive compositions have been widely used in the assembly of electrical components and the like because they are excellent in adhesive strength, high strength, heat resistance, electrical properties, and chemical resistance. However, generally, epoxy resin adhesive compositions are known to be inferior in moisture resistance because they have ether bonds and the like in the molecule. As a method for improving moisture resistance, Reference Document 1 discloses an epoxy resin adhesive composition containing an epoxy resin, a powder of a tetrafluoroethylene polymer, and a coupling agent.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the epoxy resin adhesive composition of Patent Document 1 had inferior adhesive strength after a high-temperature and high-humidity environment test at 85°C × 85% RH, and its reliability was insufficient.

[0005] The present invention has been made in view of the above situation, and an object thereof is to provide an epoxy resin adhesive composition having excellent adhesive strength after a high-temperature and high-humidity environment test at 85°C × 85% RH. <O000029>

Means for Solving the Problems

[0006] The gist of the present invention will be described below. [1] An epoxy resin adhesive composition containing the following components (A) to (D). (A) component: Epoxy resin (B) Component: A hardening agent that reacts with epoxy resin. (C) Components: Alkali metal hydroxide (D) Component: Water [2] The epoxy resin adhesive composition according to [1], wherein component (C) is sodium hydroxide or potassium hydroxide. [3] The epoxy resin adhesive composition according to [1] or [2], further comprising a silane coupling agent as component (E). [4] The epoxy resin adhesive composition according to [1] or [2], wherein the amount of component (C) is 0.2 to 20 parts by mass per 100 parts by mass of component (B). [5] The epoxy resin adhesive composition according to [1] or [2], comprising the (A) component. [6] The epoxy resin adhesive composition according to [1] or [2], wherein the component (B) comprises a polyamine compound having an amine value of 200 to 700 KOH mg / g. [7] An epoxy resin adhesive composition according to [1] or [2], used on an adherend made of an amphoteric metal. [8] A two-component epoxy resin adhesive composition comprising the following components A and B. Agent A: (A) Composition containing epoxy resin Agent B: A composition containing the following components (B) to (D). (B) Component: A hardening agent that reacts with epoxy resin. (C) Components: Alkali metal hydroxide (D) Component: Water A cured product obtained by curing either the epoxy resin adhesive composition described in [9] or [1] or the two-component epoxy resin adhesive composition described in [8]. [8] The epoxy resin adhesive composition according to [7], wherein the amphoteric metal is aluminum or zinc. [9] A two-component epoxy resin adhesive composition comprising the following components A and B. Agent A: (A) Composition containing epoxy resin Agent B: A composition containing the following components (B) to (D). (B) Component: A hardening agent that reacts with epoxy resin. (C) Components: Alkali metal hydroxide (D) Component: Water

[10] The two-component epoxy resin adhesive composition according to [9], further comprising a silane coupling agent as component (E) in component A or component B.

[11] A cured product obtained by curing either the epoxy resin adhesive composition described in [1] or the two-component epoxy resin adhesive composition described in [9]. [Effects of the Invention]

[0007] This invention provides an epoxy resin adhesive composition that exhibits excellent adhesive strength after testing in a high-temperature, high-humidity environment of 85°C × 85%RH. Furthermore, this invention provides an epoxy resin adhesive composition that exhibits excellent adhesive strength to amphoteric metals and excellent storage stability. [Modes for carrying out the invention]

[0008] The details of the invention are described below. In this specification, "X~Y" is used to mean "X or more and Y or less," including the numerical values ​​(X and Y) before and after it as the lower and upper limits, respectively. In this specification, amphoteric metals mean aluminum, zinc, tin, and lead, and oxides of amphoteric metals are not intended. <(A) component> The component (A) used in the present invention is not particularly limited as long as it is an epoxy resin. Examples of component (A) include polyfunctional epoxy resins having two or more epoxy groups, monofunctional epoxy compounds having only one epoxy group, etc., with polyfunctional epoxy resins being preferred. Furthermore, component (A) may be in liquid or solid form, but liquid form is preferred from the viewpoint of workability, and liquid form is preferred from the viewpoint of adhesive strength.

[0009] The polyfunctional epoxy resin is not particularly limited, but includes bisphenol type epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type, and bisphenol AD ​​type epoxy resin, hydrogenated bisphenol type epoxy resin, 1,2-butanediol diglycidyl ether, 1,3-butanediol diglycidyl ether, 1,4-butanediol diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 2,3-butanediol diglycidyl ether, 1,5-pentanediol diglycidyl ether, and 1,6-hexa Examples include alkylene glycol-type epoxy resins such as didiol diglycidyl ether, neopentyl glycol diglycidyl ether, and 1,4-cyclohexanedimethanol diglycidyl ether; novolac-type epoxy resins such as phenol novolac-type epoxy resins and cresol novolac-type epoxy resins; glycidylamine compounds such as N,N-diglycidyl-4-glycidyloxyaniline, 4,4'-methylenebis(N,N-diglycidylaniline), tetraglycidyldiaminodiphenylmethane, and tetraglycidyl-m-xylylenediamine; and naphthalene-type epoxy resins having four glycidyl groups. Among these, bisphenol A-type epoxy resins are preferred from the viewpoint of excellent adhesion to amphoteric metals. These may also be used individually or in mixtures.

[0010] The commercially available polyfunctional epoxy resins mentioned above are not particularly limited, but examples include jER828, 1001, 801, 806, 807, 152, 604, 630, 871, YX8000, YX8034, YX4000 (manufactured by Mitsubishi Chemical Corporation); Epiclon 830, 850, 830LVP, 850CRP, 835LV, HP4032D, 703, 720, 726, 820 (manufactured by DIC Corporation); EP4100, EP4000, EP4080, EP4085, EP4088, EPU6, EPU7N, EPR4023, EPR1 Examples include, but are not limited to, 309, EP4920 (manufactured by ADEKA Corporation), TEPIC (manufactured by Nissan Chemical Industries, Ltd.); KF-101, KF-1001, KF-105, X-22-163B, X-22-9002 (manufactured by Shin-Etsu Chemical Co., Ltd.); Denacol EX411, 314, 201, 212, 252 (manufactured by Nagase ChemteX Corporation); DER-331, 332, 334, 431, 542 (manufactured by Dow Chemical Company); YH-434, YH-434L (manufactured by Nippon Steel Chemical & Material Co., Ltd.).

[0011] The monofunctional epoxy compound is not particularly limited, but examples include n-butyl glycidyl ether, allyl glycidyl ether, 2-ethylhexyl glycidyl ether, styrene oxide, phenyl glycidyl ether, cresyl glycidyl ether, p-sec-butylphenyl glycidyl ether, glycidyl methacrylate, t-butylphenyl glycidyl ether, (poly)ethylene glycol glycidyl ether, butanediol glycidyl ether, and the like. These may be used alone or in combination of two or more.

[0012] The commercially available monofunctional epoxy compounds mentioned above are not particularly limited, but examples include ED-502, ED-502S, ED-509E, ED-509S, and ED-529 (manufactured by ADEKA Corporation). These may be used individually or in combination of two or more.

[0013] <(B) component> As the curing agent that reacts with the epoxy resin (B) used in this invention, known curing agents can be used, such as polyamine compounds, polymercaptan compounds, polyamide compounds, etc. Among them, polyamine compounds are preferred because the adhesive strength after the high-temperature and high-humidity environment test is even more excellent. In this specification, the polyamine compound may also be referred to as an amine-based curing agent. Examples of commercially available amine-based curing agents include ST12 manufactured by Mitsubishi Chemical Corporation.

[0014] The component (B) may be a solid such as a latent curing agent, but is preferably liquid at 25°C. The viscosity (25°C) of the component (B) is not particularly limited, but is 300 to 10,000 mPa·s, preferably 500 to 7,000 mPa·s, and particularly preferably 1,000 to 4,000 mPa·s. When the component (B) is a polyamine compound, the amine value is not particularly limited, but is 200 to 700 KOHmg / g, more preferably 250 to 550 KOHmg / g, and particularly preferably 300 to 450 KOHmg / g. When the viscosity or amine value is within the above range, the adhesive strength after the high-temperature and high-humidity environment test is even more excellent. The amine value represents the number of mg of potassium hydroxide equivalent to perchloric acid required to neutralize all the basic nitrogen contained in 1 g of the sample. In this invention, the amine value refers to the value measured in accordance with JIS K7237.

[0015] Examples of the polyamine compound include aliphatic polyamines, alicyclic polyamines, aromatic polyamines, polyamide amines, etc. Among them, aliphatic polyamines, alicyclic polyamines, and aromatic polyamines are preferred. Also, a mixture of two or more kinds may be used.

[0016] Examples of aliphatic polyamines include ethylenediamine, diethylenetriamine, triethylenetetramine, and hexamethylenediamine. Examples of alicyclic polyamines include mensendiamine, isophoronediamine, N-aminoethylpiperazine, diaminodicyclohexylmethane, and norbornanediamine. Examples of aromatic polyamines include xylylenediamine, metaxylylenediamine, metaphenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, and diaminodiethyldiphenylmethane. These may be used individually or in combination of two or more.

[0017] The aforementioned polymercaptan is not particularly limited, but includes 3,3'-dithiodipropionic acid, trimethylolpropane tris(thioglycolate), pentaerythritol tetrakis(thioglycolate), ethylene glycol dithioglycolate, 1,4-bis(3-mercaptobutyryloxy)butane, tris[(3-mercaptopropionyloxy)-ethyl]-isocyanurate (TEMPIC), and 1,3,5-tris(3-mercaptobutyloxyethyl)-1,3,5-triazine-2,4,6(1H,3H) Examples include ,5H)-trione, trimethylolpropanetris(3-mercaptopropionate) (TMMP), pentaerythritoltetrakis(3-mercaptopropionate) (PEMP), pentaerythritoltetrakis(3-mercaptobutyrate), dipentaerythritolhexakis(3-mercaptopropionate) (DPMP), alkyl polythiols such as 1,4-butanedithiol, 1,6-hexanedithiol, and 1,10-decanedithiol; and polythioethers containing terminal thiol groups.

[0018] Examples of the aforementioned polyamide compounds include compounds obtained by the reaction of a polyamine with a dicarboxylic acid.

[0019] The amount of component (B) added is not particularly limited, but is 1 to 200 parts by mass, preferably 2 to 100 parts by mass, and especially preferably 3 to 75 parts by mass, per 100 parts by mass of component (A). This range is preferred because it provides excellent adhesion to amphoteric metals.

[0020] <(C) component> The component (C) used in the present invention is not particularly limited as long as it is an alkali metal hydroxide. When the (C) component is combined with the other components of the present invention, it can produce remarkable effects such as excellent adhesion to amphoteric metals, adhesion after high temperature and high humidity environment testing, and storage stability. The (C) component is not particularly limited, but examples include sodium hydroxide, potassium hydroxide, lithium hydroxide, and rubidium hydroxide, among which sodium hydroxide and potassium hydroxide are preferred due to their excellent adhesion to amphoteric metals. These may be used alone or in combination of two or more.

[0021] The amount of component (C) is 0.001 to 20 parts by mass per 100 parts by mass of component (A), preferably 0.01 to 10 parts by mass, and particularly preferably 0.05 to 5 parts by mass. Alternatively, the amount of component (C) is 0.001 to 40 parts by mass per 100 parts by mass of component (B), preferably 0.005 to 20 parts by mass, and particularly preferably 0.01 to 10 parts by mass. Within these ranges, the adhesion to amphoteric metals, the adhesion after high temperature and high humidity environment testing, and storage stability are further improved.

[0022] <(D) component> Component (D) of the present invention is not particularly limited as long as it is water, but examples include distilled water and deionized water. By combining component (D) of the present invention with other components, remarkable effects such as superior adhesion to amphoteric metals, adhesion after high temperature and high humidity environment testing, and storage stability can be obtained. Component (D) can act as a solvent for dissolving component (C).

[0023] The amount of component (D) added is not particularly limited, but is 0.01 to 10 parts by mass, preferably 0.05 to 5 parts by mass, and especially preferably 0.1 to 3 parts by mass, per 100 parts by mass of component (A). Alternatively, the amount of component (D) added is 0.01 to 20 parts by mass, preferably 0.02 to 10 parts by mass, and especially preferably 0.03 to 6 parts by mass, per 100 parts by mass of component (B). Alternatively, the amount of component (D) added is 0.1 to 300 parts by mass, preferably 0.5 to 200 parts by mass, and especially preferably 1 to 150 parts by mass, per 1 part by mass of component (C). Within these ranges, the adhesion to amphoteric metals, adhesion after high temperature and high humidity environment testing, and storage stability are further improved.

[0024] <(E) component> Furthermore, the epoxy resin adhesive composition of the present invention may include a silane coupling agent as component (E). Component (E) of the present invention, when combined with the other components of the present invention, has the effect of providing even better adhesive strength after high-temperature and high-humidity environmental testing.

[0025] The silane coupling agents include glycidyl group-containing silane coupling agents such as 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 3-glycidoxypropylmethyldiethoxysilane, as well as vinyl group-containing silane coupling agents such as vinyltris(β-methoxyethoxy)silane, vinyltriethoxysilane, and vinyltrimethoxysilane. Examples include (meth)acrylic group-containing silane coupling agents such as γ-methacryloxypropyltrimethoxysilane, amino group-containing silane coupling agents such as N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and N-phenyl-γ-aminopropyltrimethoxysilane, as well as γ-mercaptopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, styrylsilane, ureidosilane, sulfidosilane, and isocyanatesilane. Among these, glycidyl group-containing silane coupling agents and amino group-containing silane coupling agents are preferred. These may be used alone or in combination of two or more.

[0026] The amount of component (E) added is not particularly limited, but is 0.1 to 20 parts by mass, preferably 0.2 to 15 parts by mass, and most preferably 0.3 to 10 parts by mass, per 100 parts by mass of component (A). Alternatively, the amount of component (E) added per 100 parts by mass of component (B) is 0.1 to 20 parts by mass, preferably 0.2 to 15 parts by mass, and most preferably 0.3 to 10 parts by mass. By being within the above range, the effect of even better adhesive strength after high temperature and high humidity environment testing can be obtained.

[0027] <Optional ingredients> In addition to the present invention, additives such as curing accelerators, fillers, various elastomers including styrene copolymers, preservative stabilizers, antioxidants, flame retardants, light stabilizers, heavy metal deactivators, plasticizers, defoamers, pigments, rust inhibitors, leveling agents, dispersants, rheology modifiers, flame retardants, and surfactants can be used, to the extent that the objectives of the present invention are not impaired. Examples of fillers include silica, glass, ceramics, calcium carbonate, carbon powder, and kaolin clay.

[0028] <Two-component epoxy resin adhesive composition> One embodiment of the present invention is a two-component epoxy resin adhesive composition containing agent A and agent B, wherein agent A is a composition containing component (A), and agent B is a composition containing components (B) to (D). By separating the components into separate liquids in this way, unnecessary reactions during storage can be suppressed, and storage stability can be improved. In such a two-component epoxy resin adhesive composition, each liquid can be manufactured by mixing by a well-known method. The two liquids are then mixed and used at the time of use. The amount of agent B is in the range of 5 to 300 parts by mass, more preferably 10 to 200 parts by mass, and particularly preferably 20 to 150 parts by mass, per 100 parts by mass of agent A. A cured product can be obtained by mixing and stirring agent A and agent B before use.

[0029] <Cured product> A cured product obtained by curing the epoxy resin adhesive composition of the present invention is also an embodiment of the invention. The curing conditions for the epoxy resin adhesive composition are not particularly limited, but a temperature of 0°C or higher and less than 150°C is preferred, and more preferably 10°C or higher and less than 130°C. The curing time is not particularly limited, but for example, it can be 10 minutes to 30 days.

[0030] Furthermore, a cured product obtained by curing the two-component epoxy resin adhesive composition of the present invention is also an embodiment of the invention. Curing by two-component mixing means that the two liquids can be cured by mixing them at the time of use. The curing conditions for the two-component epoxy resin adhesive composition are not particularly limited, but a temperature of 0°C or higher and less than 150°C after mixing the two liquids is preferred, and more preferably 10°C or higher and less than 130°C. The curing time is not particularly limited, but for example, it can be 10 minutes to 30 days.

[0031] <Application> Specific applications of the epoxy resin adhesive composition of the present invention include: Because the present invention is an epoxy resin adhesive composition with excellent adhesive strength after high-temperature and high-humidity environmental testing at 85°C × 85%RH, it can be used in the automotive and transportation equipment field as an adhesive for automotive switch parts, headlamps, engine internal components, electrical components, drive engines, brake oil tanks, etc. It can also be used in flat panel displays as an adhesive for liquid crystal displays, organic electroluminescent displays, light-emitting diode displays, and field emission displays. It can be used as an adhesive in the field of electronic mobile devices such as mobile phones and multifunction mobile phones. In the recording field, it can be used as an adhesive for video discs, CDs, DVDs, MDs, pickup lenses, hard disk peripherals (spindle motor components, magnetic head actuator components, etc.), and Blu-ray discs. In the electronic materials field, examples include sealing materials for electronic components, electrical circuits, electrical contacts, or semiconductor elements, die bonding agents, conductive adhesives, anisotropic conductive adhesives, interlayer adhesives for multilayer substrates including build-up substrates, and solder resists. In the battery field, it can be used as an adhesive for lithium-ion batteries, manganese batteries, alkaline batteries, nickel-based batteries, fuel cells, silicon-based solar cells, dye-sensitized solar cells, and organic solar cells. In the optical components field, it can be used as an adhesive for optical fiber materials around optical switches and connectors in optical communication systems, as well as for optical passive components, optical circuit components, and around optoelectronic integrated circuits. In the optical equipment field, it can be used as an adhesive for lens materials in still cameras, as well as for viewfinder prisms, target prisms, viewfinder covers, light-receiving sensors, photographic lenses, and projection lenses in projection televisions. In the infrastructure field, it can be used as an adhesive for components and modules that are left in outdoor environments for long periods, such as outdoor communication equipment and traffic lights. [Examples]

[0032] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0033] <Preparation of a two-component epoxy resin adhesive composition> Each component was taken in parts by mass as shown in Table 1 and mixed in a mixer at room temperature for 60 minutes to prepare components A and B, which correspond to the two-component epoxy resin adhesive composition. Detailed preparation amounts are shown in Table 1, and all values ​​are expressed in parts by mass. In Examples 1-5, component (C) was first dissolved in component (D) to create an aqueous solution before being added.

[0034] <(A) component> a1: Bisphenol A type epoxy resin (JER828, manufactured by Mitsubishi Chemical Corporation) <(B) component> b1: An amine-based curing agent (ST12, manufactured by Mitsubishi Chemical Corporation) with a viscosity of 1700 mPa·s at 25℃ and an amine value of 365 KOH mg / g. <(C) component> c1: Sodium hydroxide (reagent) c2: Potassium hydroxide (reagent) <(D) component> d1: Ion-exchanged water <(E) component> e1:3-Glycidoxypropyltrimethoxysilane (KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.)

[0035] The test methods used in the examples and comparative examples in Table 1 are as follows:

[0036] <(1) AL / AL Tensile Shear Bonding Strength Test (Initial)> A mixed resin composition was prepared by mixing 100 parts by mass of A and 50 parts by mass of B, as described in Table 1. Next, the mixed resin composition was applied to an aluminum test piece measuring 25 mm wide × 100 mm long × 1.0 mm thick. Then, another aluminum test piece measuring 25 mm wide × 100 mm long × 1.0 mm thick was attached to the mixed resin composition so that the overlapping surface was 25 mm × 10 mm and secured with clips. The test piece was then cured in a hot air drying oven set to 120°C for 30 minutes. Subsequently, the shear adhesive strength (in MPa) was measured using a universal tensile testing machine (tensile speed 10 mm / min.) at 25°C according to JIS K 6850, and the maximum value was measured. The results are shown in Table 1. In this invention, a value of 10 MPa or higher is preferred, and more preferably 12 MPa or higher. In the table, "Not Evaluable" means that component (C) did not dissolve in the entire composition and therefore could not be evaluated.

[0037] <(2) AL / AL tensile shear bond strength test after high temperature and high humidity environment test at 85℃ × 85%RH> A mixed resin composition was prepared by mixing 100 parts by mass of agent A with 50 parts by mass of agent B, as described in Table 1. Next, the mixed resin composition was applied to an aluminum test piece measuring 25 mm wide × 100 mm long × 1.0 mm thick. Then, another aluminum test piece measuring 25 mm wide × 100 mm long × 1.0 mm thick was attached to the first test piece so that the overlapping surface was 25 mm × 10 mm and secured with clips. The test pieces were then cured in a hot air drying oven set to 120°C for 30 minutes to obtain test specimens. After that, each test specimen was placed in a high-temperature, high-humidity chamber set to 85°C × 85%RH for 240 hours. After being removed from the chamber, it was left at room temperature for 1 hour. Then, the shear bond strength (in MPa) was measured using a universal tensile testing machine (tensile speed 10 mm / min.) at 25°C according to JIS K 6850. The results are shown in Table 1. In this invention, from the viewpoint of reliability, a pressure of 16 MPa or higher is preferred, more preferably 18 MPa or higher, and particularly preferably 19 MPa or higher. In the table, "Not Evaluable" means that component (C) did not dissolve in the entire composition and therefore could not be evaluated.

[0038] [Table 1]

[0039] Examples 1 to 5 in Table 1 demonstrate that the present invention can provide an epoxy resin adhesive composition that exhibits excellent adhesive strength after high-temperature and high-humidity environmental testing at 85°C × 85%RH.

[0040] Furthermore, Comparative Example 1 in Table 1 is a composition that does not contain components (C) and (D) of the present invention, but it showed inferior adhesive strength after high temperature and high humidity environment testing. Also, since Comparative Example 2 is a composition that does not contain component (C), it was not possible to evaluate it because component (C) did not dissolve throughout the composition.

[0041] Furthermore, (3) a Zn / Zn tensile shear bond strength test after the 85°C × 85%RH high-temperature and high-humidity environment test and (4) a storage stability confirmation test were performed.

[0042] <(3) Zn / Zn tensile shear bond strength test after high temperature and high humidity environment test at 85℃ × 85%RH> A mixed resin composition was prepared by mixing 100 parts by mass of A with 50 parts by mass of B, using the A and B components from Examples 1 and 4 and Comparative Example 1 in Table 1. Next, the mixed resin composition was applied to a zinc test piece measuring 25 mm wide × 100 mm long × 1.0 mm thick. Then, another zinc test piece measuring 25 mm wide × 100 mm long × 1.0 mm thick was attached to the test piece so that the overlapping surface was 25 mm × 10 mm and secured with clips. The test pieces were then cured in a hot air drying oven set to 120°C for 30 minutes to obtain test specimens. After that, each test piece was placed in a high-temperature, high-humidity chamber set to 85°C × 85%RH for 240 hours. After being removed from the chamber, it was left at room temperature for 1 hour. Then, the shear adhesive strength (in MPa) was measured using a universal tensile testing machine (tensile speed 10 mm / min.) at 25°C according to JIS K 6850, and the maximum value was measured. In this invention, from the viewpoint of reliability, a pressure of 3 MPa or higher is preferred, more preferably 4 MPa or higher, and particularly preferably 5 MPa or higher. The results were 4.8 MPa for Example 1, 5.5 MPa for Example 4, and 2.7 MPa for Comparative Example 1. From these results, it was confirmed that the epoxy resin adhesive composition according to the present invention has excellent adhesive strength not only to aluminum but also to zinc under high temperature and high humidity conditions, and thus it was found to be effective on amphoteric metals in general.

[0043] <(4) Storage stability confirmation test> After storing agents A and B of Example 1 in Table 1 at 25°C for 2 months, a test similar to the AL / AL tensile shear adhesive strength test after the 85°C × 85%RH high temperature and high humidity environment test described above was performed. In the present invention, from the viewpoint of reliability, 16 MPa or higher is preferred, more preferably 18 MPa or higher, and particularly preferably 19 MPa or higher. The result for Example 1 was 19.8 MPa, which did not change from the initial result. Therefore, it was confirmed that the present invention has excellent storage stability. [Industrial applicability]

[0044] This invention provides an epoxy resin adhesive composition that exhibits excellent adhesive strength after testing in a high-temperature, high-humidity environment of 85°C and 85%RH, making it suitable for various adhesive applications. In particular, it is industrially useful as an adhesive for infrastructure components that are left in outdoor environments for extended periods.

Claims

1. It contains the following components (A) to (D): The above-mentioned (C) component is present in an amount of 0.001 to 40 parts by mass per 100 parts by mass of component (B), The above-mentioned (D) component is present in an amount of 0.01 to 20 parts by mass per 100 parts by mass of component (B), The viscosity of component (B) at 25°C is 500 to 7,000 mPa·s, and the amine value is 300 to 450 KOH mg / g. Epoxy resin adhesive composition. (A) Component: Bisphenol-type epoxy resin (B) Component: A hardening agent that reacts with epoxy resin. (C) Ingredients: Sodium hydroxide or potassium hydroxide (D) Component: water

2. The epoxy resin adhesive composition according to claim 1, wherein component (A) is a bisphenol A type epoxy resin.

3. Furthermore, the epoxy resin adhesive composition according to claim 1 or 2, comprising a silane coupling agent as component (E).

4. The epoxy resin adhesive composition according to claim 1 or 2, wherein the amount of component (C) is 0.001 to 20 parts by mass per 100 parts by mass of component (A).

5. The epoxy resin adhesive composition according to claim 1 or 2, wherein the component (B) is a polyamine compound.

6. The epoxy resin adhesive composition according to claim 1 or 2, wherein the amount of component (D) is 0.01 to 10 parts by mass per 100 parts by mass of component (A).

7. An epoxy resin adhesive composition according to claim 1 or 2, for use on an adherend made of an amphoteric metal.

8. The epoxy resin adhesive composition according to claim 7, wherein the amphoteric metal is aluminum or zinc.

9. The following components A and B are included, and the (C) component is present in a quantity of 0.001 to 40 parts by mass per 100 parts by mass of component (B). (B) contains 0.01 to 20 parts by mass of component (D) per 100 parts by mass of component (B), The viscosity of component (B) at 25°C is 500 to 7,000 mPa·s, and the amine value is 300 to 450 KOH mg / g. A two-component epoxy resin adhesive composition. Agent A: (A) Bisphenol-type epoxy resin Agent B: A composition containing the following components (B) to (D). (B) Component: A hardening agent that reacts with epoxy resin. (C) Ingredients: Sodium hydroxide or potassium hydroxide (D) Component: water

10. Furthermore, the two-component epoxy resin adhesive composition according to claim 9, wherein component A or component B contains a silane coupling agent as component (E).

11. A cured product obtained by curing either the epoxy resin adhesive composition described in claim 1 or the two-component epoxy resin adhesive composition described in claim 9.

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