2-Cyanoacrylate adhesive composition

Abstract

To provide an adhesive composition that is primarily composed of alkoxyalkyl 2-cyanoacrylate and has improved moist-heat resistance.SOLUTION: The extensive and intensive study of the inventors has found out that the problem herein can be solved by an adhesive composition comprising (B) at least one selected from the group consisting of a polycarboxylic acid having a norbornene structure, a polycarboxylic acid having a norbornane structure, and acid anhydrides thereof, at a specific ratio to (A) alkoxyalkyl 2-cyanoacrylate.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to a 2-cyanoacrylate adhesive composition known as an instant adhesive. [Background technology]

[0002] 2-cyanoacrylate adhesive compositions, due to the unique anionic polymerization properties of their main component, 2-cyanoacrylate, initiate polymerization upon contact with even a small amount of moisture on the surface of the adherend, and harden to bond various materials strongly in a short time. Therefore, they are widely used as so-called instant adhesives in industrial, medical, and household applications.

[0003] However, while general 2-cyanoacrylate adhesive compositions have excellent bonding speed (curing speed), they sometimes exhibit a characteristic odor and irritancy, and can cause contamination of the surrounding surface (whitening phenomenon). Depending on the application, improvements to these issues may be required. These problems are partly due to the high reactivity and high vapor pressure of ethyl 2-cyanoacrylate, which is commonly used in 2-cyanoacrylate adhesive compositions. One method that can solve these problems is to use a 2-cyanoacrylate monomer with a large molecular weight and low vapor pressure, such as alkoxyalkyl 2-cyanoacrylate, as the main component (for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 10-176142 [Overview of the project] [Problems that the invention aims to solve]

[0005] The present inventors focused on an adhesive composition containing alkoxyalkyl 2-cyanoacrylate as the main component in order to improve the odor, irritation, and contamination of the surrounding area of ​​the adherend when using a 2-cyanoacrylate adhesive composition. In order to evaluate the humidity and heat resistance of the adhesive composition, they exposed adherends using the adhesive composition to high temperature and high humidity conditions after bonding. They found that the adhesive strength was significantly lower compared to an adhesive composition containing ethyl 2-cyanoacrylate as the main component, which is commonly used as a 2-cyanoacrylate adhesive composition, and in some cases, it peeled off completely.

[0006] The present invention aims to provide an adhesive composition mainly composed of alkoxyalkyl 2-cyanoacrylate with improved moisture and heat resistance. [Means for solving the problem]

[0007] As a result of diligent research by the present inventors to solve the above problems, they have found that the above problems can be solved by providing an adhesive composition containing at least one selected from the group consisting of polycarboxylic acids having a norbornene structure, polycarboxylic acids having a norbornane structure, and acid anhydrides thereof, in a specific ratio with respect to alkoxyalkyl 2-cyanoacrylate. Specifically, the present invention includes the following inventions.

[0008] [1] An adhesive composition containing (A) and (B) below, wherein the content of (B) is 0.05 to 5 parts by weight per 100 parts by weight of (A). (A) Alkoxyalkyl 2-cyanoacrylate (B) At least one selected from the group consisting of polycarboxylic acids having a norbornene structure, polycarboxylic acids having a norbornane structure, and acid anhydrides thereof.

[0009] [2] The above (B) is the following general formula (1):

[0010] [ka] (In the formula, R1 represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 9 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 14 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms.) Compounds represented by the following general formula (2): and their acid anhydrides, the following general formula (2):

[0011] [ka] (In the formula, R2 represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 9 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 14 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms.) Compounds represented by the following general formula (3): and their acid anhydrides, the following general formula (3):

[0012] [ka] (In the formula, X1 represents a single bond, a C1-C6 alkylidene group which may have branches, a C5-C14 cycloalkylidene group which may have branches, a C5-C14 oxocycloalkylene group which may have branches, a phenylene group, a 1-phenylethane-1,1-diyl group, a 1,1-diphenylmethane-1,1-diyl group, or a fluorenylidene group. 3a and R 3b Each of these independently represents a hydrogen atom, a C1-C20 alkyl group which may be branched, a C3-C9 cycloalkyl group which may be branched, an C2-C20 alkenyl group which may be branched, an aryl group which may be C6-C14, or an aralkyl group which may be C7-C18. Compounds represented by the following general formula (4):

[0013] [ka] (In the formula, R 4a and R 4bEach independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may have a branch, a cycloalkyl group having 3 to 9 carbon atoms, an alkenyl group having 2 to 20 carbon atoms which may have a branch, an aryl group having 6 to 14 carbon atoms or an aralkyl group having 7 to 18 carbon atoms. n1 represents an integer of 0 to 9.) The adhesive composition according to [1], which is at least one selected from the group consisting of compounds represented by .

[0014] [3] Furthermore, the adhesive composition according to [1] or [2], which contains 0.5 to 25 parts by weight of a thickener with respect to 100 parts by weight of (A) alkoxyalkyl 2-cyanoacrylate. [Advantages of the Invention]

[0015] According to the present invention, it is possible to provide an adhesive composition containing an alkoxyalkyl 2-cyanoacrylate having improved heat and humidity resistance as a main component. The adhesive composition of the present invention is excellent in heat and humidity resistance, and also has excellent low whitening property as compared with an adhesive composition containing ethyl 2-cyanoacrylate, which is widely used as a 2-cyanoacrylate-based adhesive composition, as a main component. Therefore, it can be suitably used for bonding electrical components for home appliances and automobiles, and products with high design. In addition, since the adhesive composition of the present invention gives a cured product having no cloudiness and excellent transparency, it can also be suitably used particularly in fields where transparency is required. [Embodiments for Carrying Out the Invention]

[0016] [(A) Alkoxyalkyl 2-cyanoacrylate]< Examples of alkoxyalkyl 2-cyanoacrylates included in the adhesive composition of the present invention include esters of 2-cyanoacrylic acid such as methoxyethyl, methoxypropyl, methoxyisopropyl, methoxybutyl, ethoxyethyl, ethoxypropyl, ethoxyisobutyl, propoxymethyl, propoxyethyl, propoxypropyl, butoxymethyl, butoxyethyl, butoxypropyl, butoxyisopropyl, and butoxybutyl. Among these alkoxyalkyl 2-cyanoacrylates, ethoxyethyl 2-cyanoacrylate and methoxyethyl 2-cyanoacrylate are preferred because they have a significant effect in reducing the odor and irritancy of 2-cyanoacrylate-based adhesive compositions and easily improve adhesive properties. These alkoxyalkyl 2-cyanoacrylates may be used alone or in combination of two or more.

[0017] These alkoxyalkyl 2-cyanoacrylates can be produced by conventional methods (for example, by Kneefengel condensation of alkoxyalkyl 2-cyanoacetate and formaldehyde, followed by thermal depolymerization), and are also available commercially.

[0018] The weight percentage of alkoxyalkyl 2-cyanoacrylate in the total amount of the adhesive composition of the present invention is, for example, 50% by weight or more, preferably 70% by weight or more, and more preferably 80% by weight or more.

[0019] <(B) Polycarboxylic acids having norbornene structures, polycarboxylic acids having norbornane structures, and acid anhydrides thereof> In the present invention, "polycarboxylic acid" refers to a compound having two or more carboxyl groups in its molecule. Furthermore, the acid anhydride may have all carboxyl groups having an acid anhydride structure [-CO-O-CO-], or some of the carboxyl groups may have an anhydride structure. In the adhesive composition of the present invention, it is preferable to include at least one compound selected from the group consisting of the compound represented by general formula (1) and its acid anhydride, the compound represented by general formula (2) and its acid anhydride, the compound represented by general formula (3), and the compound represented by general formula (4), among polycarboxylic acids having a norbornene structure, polycarboxylic acids having a norbornane structure, and their acid anhydrides.

[0020] In substituent R1 of the above general formula (1), the alkyl group having 1 to 20 carbon atoms may be branched. Among alkyl groups having 1 to 20 carbon atoms, alkyl groups having 1 to 9 carbon atoms are preferred. Examples of alkyl groups having 1 to 20 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, sec-pentyl group, tert-pentyl group, neopentyl group, 2,-methylbutyl group, 1-ethylpropyl group, n-hexyl group, isohexyl group, sec-hexyl group, tert-hexyl group, neohexyl group, 2,-methylpentyl group, 3-methylpentyl group, 1,2-dimethylbutyl group, 2,2-dimethyl and 1-ethylpropyl group. Examples of C3-C9 cycloalkyl groups include cyclopropyl group, cyclobutyl group, n-heptyl group, isoheptyl group, sec-heptyl group, tert-heptyl group, neoheptyl group, 2-methylhexyl group, 3-methylhexyl group, 2,2-dimethylpentyl group, 3-ethylpentyl group, 2,4-dimethylpentyl group, 1-ethyl-1-methylbutyl group, 1,2,3-trimethylbutyl group, n-octyl group, isooctyl group, sec-octyl group, tert-octyl group, neooctyl group, n-nonyl group, isononyl group, sec-nonyl group, tert-nonyl group, neononyl group, etc. Examples of C3-C9 cycloalkyl groups include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclononyl group, etc. C2-C20 alkenyl groups may be branched. Furthermore, among alkenyl groups having 2 to 20 carbon atoms, alkenyl groups having 2 to 12 carbon atoms are preferred.Examples of alkenyl groups having 2 to 20 carbon atoms include vinyl group, allyl group, 1-propenyl group, isopropenyl group, 1-butenyl group, 2-butenyl group, 3-butenyl group, 2-methyl-2-propenyl group, 1-pentenyl group, 2-pentenyl group, 3-pentenyl group, 4-pentenyl group, 2-methyl-2-butenyl group, 1,2-dimethyl-2-propenyl group, 1-hexenyl group, 2-hexenyl group, 3-hexenyl group, and 4-hexenyl group. Examples of C6-C14 aryl groups include 5-hexenyl group, 2-methyl-2-pentenyl group, 1-heptenyl group, 2-heptenyl group, 3-heptenyl group, 4-heptenyl group, 5-heptenyl group, 6-heptenyl group, 1-octenyl group, 2-octenyl group, 1-nonenyl group, decenyl group, undecenyl group, dodecenyl group, tridecenyl group, tetradecenyl group, pentadecenyl group, hexadecenyl group, heptadecenyl group, octadecenyl group, nonadecenyl group, etc. Examples of C6-C14 aryl groups include phenyl group, tolyl group, t-butylphenyl group, naphthyl group, anthracenyl group, etc. Examples of aralkyl groups having 7 to 18 carbon atoms include benzyl group, phenethyl group, cumyl group, hydrocinnamyl group, benthhydryl group, methylbenzyl group, and t-butylbenzyl group.

[0021] Among the compounds represented by the above general formula (1), compounds represented by the above general formula (1) and their acid anhydrides are preferred, with 5-norbornene-2,3-dicarboxylic acid, 5-norbornene-2,3-dicarboxylic acid anhydride, methyl-5-norbornene-2,3-dicarboxylic acid, and methyl-5-norbornene-2,3-dicarboxylic acid anhydride being more preferred.

[0022] In the R2 of the above general formula (2), examples of alkyl groups having 1 to 20 carbon atoms, cycloalkyl groups having 3 to 9 carbon atoms, alkenyl groups having 2 to 20 carbon atoms, aryl groups having 6 to 14 carbon atoms, and aralkyl groups having 7 to 18 carbon atoms include the same as those in the above general formula (1) described above.

[0023] Among the compounds represented by the above general formula (2), compounds represented by the above general formula (2) and their acid anhydrides are preferred, with 5-norbornane-2,3-dicarboxylic acid, 5-norbornane-2,3-dicarboxylic acid anhydride, methyl-5-norbornane-2,3-dicarboxylic acid, and methyl-5-norbornane-2,3-dicarboxylic acid anhydride being more preferred.

[0024] In the above general formula (3), X1 represents a single bond, a C1-C6 alkylidene group which may have branches, a C5-C4 cycloalkylidene group which may have branches, a C5-C4 oxocycloalkylene group which may have branches, a C5-C4 phenylene group which may have branches, a 1-phenylethane-1,1-diyl group which may have branches, a 1,1-diphenylmethane-1,1-diyl group which may have branches, or a fluorenylidene group which may have branches. Examples of a C1-C6 alkylidene group which may have branches include isopropylidene, methylene, ethylidene, and butane-2,2-diyl groups which may have branches. Examples of a C5-C4 cycloalkylidene group which may have branches include cyclohexylidene, 3,5,5-trimethylcyclohexylidene, and cyclododecylidene groups which may have branches. Examples of oxocycloalkylene groups having 5 to 14 carbon atoms that may have branching include oxocyclopentylene, oxocyclohexylene, and oxocyclododecylene groups.

[0025] R in the above general formula (3) 3a , R 3b In this, examples of the optionally branched alkyl groups having 1 to 20 carbon atoms, cycloalkyl groups having 3 to 9 carbon atoms, optionally branched alkenyl groups having 2 to 20 carbon atoms, aryl groups having 6 to 14 carbon atoms, and aralkyl groups having 7 to 18 carbon atoms include the same substituents R1 as those in the general formula (1) described above.

[0026] Among the compounds represented by the above general formula (3), including stereoisomers, 5,5-(1,4-phenylene)bis(hexahydro-4,7-methanoisobenzofuran-1,3-dione) and dodecahydro(5,5'-bi-4,7-methanoisobenzofuran)-1,1',3,3'-tetraone are preferred, and 5,5-(1,4-phenylene)bis(hexahydro-4,7-methanoisobenzofuran-1,3-dione) is more preferred.

[0027] R in the above general formula (4) 4a , R 4b In this, examples of the optionally branched alkyl groups having 1 to 20 carbon atoms, cycloalkyl groups having 3 to 9 carbon atoms, optionally branched alkenyl groups having 2 to 20 carbon atoms, aryl groups having 6 to 14 carbon atoms, and aralkyl groups having 7 to 18 carbon atoms include the same substituents R1 as those in the general formula (1) described above.

[0028] In the above general formula (4), n represents an integer from 0 to 9, preferably from 0 to 1.

[0029] Among the compounds represented by the above general formula (4), norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic dianhydride is preferred.

[0030] Among the above-mentioned (B) polycarboxylic acids having a norbornene structure, polycarboxylic acids having a norbornane structure, and their acid anhydrides, the compounds represented by the above general formula (1) in which R1 is a hydrogen atom or an alkyl group having 1 to 9 carbon atoms, and their acid anhydrides, the compounds represented by the above general formula (2) in which R2 is a hydrogen atom or an alkyl group having 1 to 9 carbon atoms, and their acid anhydrides, 5,5-(1,4-phenylene)bis(hexahydro-4,7-methanoisobenzofuran-1,3-dione), dodecahydro(5,5'-bi-4,7-methanoisobenzofuran)-1,1',3,3'-tetraone, norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic acid Aqueous compounds are preferred, and 5-norbornene-2,3-dicarboxylic acid, 5-norbornene-2,3-dicarboxylic acid anhydride, methyl-5-norbornene-2,3-dicarboxylic acid, methyl-5-norbornene-2,3-dicarboxylic acid anhydride, 5-norbornane-2,3-dicarboxylic acid, 5-norbornane-2,3-dicarboxylic acid anhydride, methyl-5-norbornane-2,3-dicarboxylic acid, methyl-5-norbornane-2,3-dicarboxylic acid anhydride, 5,5-(1,4-phenylene)bis(hexahydro-4,7-methanoisobenzofuran-1,3-dione), norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic dianhydride are more preferred. Furthermore, the compounds listed as (B) polycarboxylic acids having a norbornene structure, polycarboxylic acids having a norbornane structure, and their acid anhydrides may be used individually or in combination of two or more.

[0031] (B) Polycarboxylic acids having a norbornene structure, polycarboxylic acids having a norbornane structure, and their acid anhydrides may be commercially available products. Examples of commercially available products include 5-norbornene-2,3-dicarboxylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), Kayahard CD, Kayahard MCD (manufactured by Nippon Kayaku Co., Ltd.), MHAC-P (manufactured by Showa Denko Materials Co., Ltd.), Hymic anhydride / Nadic anhydride (manufactured by Puyang Huigheng Electronic Material Co., Ltd.), hexahydro-4,7-methanoisobenzofuran-1,3-dione (5-norbornane-2,3-dicarboxylic acid anhydride / Fujifilm Wako Pure Chemical Industries, Ltd.), ENEHYDE BzDA (manufactured by ENEOS Corporation), ENEHYDE BzDAxx (manufactured by ENEOS Corporation), ENEHYDE CpODA (manufactured by ENEOS Corporation), etc.

[0032] In the adhesive composition of the present invention, the content of at least one selected from the group consisting of polycarboxylic acids having a norbornene structure, polycarboxylic acids having a norbornane structure, and acid anhydrides thereof is usually 0.05 to 5 parts by weight, preferably 0.08 to 4 parts by weight, per 100 parts by weight of alkoxyalkyl 2-cyanoacrylate. By setting the content in the range of 0.05 to 5 parts by weight, the penetration of moisture into the adhesive layer can be suppressed, the resistance to humidity and heat can be improved, and an adhesive composition with excellent storage stability can be obtained.

[0033] The adhesive composition of the present invention may contain, as necessary, various additives commonly used in 2-cyanoacrylate adhesive compositions, in addition to at least one selected from the group consisting of alkoxyalkyl 2-cyanoacrylate, polycarboxylic acid having a norbornene structure, polycarboxylic acid having a norbornane structure, and acid anhydrides thereof. The additives that may be included will be described in detail below.

[0034] <Thickening agent> The thickening agent is not particularly limited as long as it dissolves in alkoxyalkyl 2-cyanoacrylate and exhibits a thickening effect. Examples include acrylic resins, acrylic rubber, polyvinyl chloride, polystyrene, cellulose esters, polyalkyl-2-cyanoacrylate, ethylene-vinyl acetate copolymers, and polymers of methacrylic acid esters and / or acrylic acid esters. Examples of the methacrylic acid ester include methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, butyl methacrylate, isobutyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, 2-ethylhexyl methacrylate, nonyl methacrylate, methoxyethyl methacrylate, methoxypropyl methacrylate, ethoxyethyl methacrylate, ethoxypropyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, allyl methacrylate, and tetrahydrofryl methacrylate. Examples of the acrylic acid esters include methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, isobutyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate, methoxyethyl acrylate, methoxypropyl acrylate, ethoxyethyl acrylate, ethoxypropyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, allyl acrylate, and tetrahydrofryl acrylate. Specific examples of acrylic resins include homopolymers of the monomers such as polymethyl methacrylate, polyethyl methacrylate, polypropyl methacrylate, and polybutyl methacrylate, as well as copolymers consisting of two or more types, terpolymers, tetramers, etc. Among these thickeners, acrylic resins are preferred, polymers of methacrylate esters are more preferred, and polymers of methyl methacrylate are even more preferred. These thickeners may be used alone or in combination of two or more types.

[0035] The viscosity of the adhesive composition of the present invention can be appropriately determined according to its application. When a thickening agent is included, its content is, for example, 0.5 to 25 parts by weight, preferably 1.0 to 15 parts by weight, per 100 parts by weight of alkoxyalkyl 2-cyanoacrylate. Within the range of 0.5 to 25 parts by weight, sufficient thickening effect is achieved, improving handling during application and suppressing deterioration of storage stability. As shown in the examples section below, normally, adding a thickening agent reduces heat and humidity resistance (for example, comparing Comparative Examples 10 and 12). However, with the adhesive composition of the present invention, even when a thickening agent is added within the above usage range, heat and humidity resistance does not decrease, and in some cases, it can even be improved.

[0036] <Adhesion enhancer> The adhesion-enhancing agent is not particularly limited as long as it dissolves in alkoxyalkyl 2-cyanoacrylate and exhibits an effect of increasing intermolecular hydrogen bonding. Examples include aromatic carboxylic acids and their esters, and aromatic polyvalent hydroxy compounds. Specifically, examples include benzoic acid, phthalic acid, salicylic acid, pyrogallol, 1,2,4-trihydroxybenzene, phloroglucinol, benzenetetraol, benzenehexaol, resorcinol, garlicic acid, ethyl garlicate, and methoxyethyl garlicate. These adhesion-enhancing agents may be used alone or in combination of two or more. When an adhesion-enhancing agent is included, its content is, for example, 0.001 to 2.0 parts by weight, preferably 0.01 to 1.0 parts by weight, per 100 parts by weight of alkoxyalkyl 2-cyanoacrylate.

[0037] <Curing accelerator> The curing accelerator is not particularly limited as long as it dissolves in alkoxyalkyl 2-cyanoacrylate and exhibits an effect of improving the curing speed. Examples include polyalkylene oxide derivatives and calixalene compounds.

[0038] Examples of polyalkylene oxide derivatives include the following general formula (5):

[0039] [ka] (In the above general formula (5), X2 and X3 each independently represent a hydrogen atom, a halogen atom, a hydroxyl group, or a substituted or unsubstituted alkyl, alkenyl, aryl, or aralkyl group. p is an integer of 1 or more, q is an integer of 2 or more, and the terminals may form rings.) Examples of compounds having repeating units represented by include

[0040] Among the polyalkylene oxide derivatives represented by the above general formula (5), chain-like polyalkylene oxide derivatives include, for example, formaldehyde condensates, acetaldehyde condensates, trioxane, polyalkylene glycols (e.g., diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol (400) (e.g., 1000), dipropylene glycol, polypropylene glycol, polytetramethylene oxide, poly-3,3-bis(chloromethyl)butylene oxide, poly-1,3-dioxolane, ethylene oxide-propylene oxide block polymer, etc.), polyalkylene glycol monoethers (e.g., methyl carbitol, carbitol, diethylene glycol butyl ether, diethylene glycol phenyl ether, diethylene glycol benzyl ether, dipropylene glycol ethyl ether, tripropylene glycol methyl ether, polyethylene glycol methyl ether, polyethylene glycol propyl ether, polyethylene glycol lauryl ether, polyethylene glycol stearyl ether, polyoxyethylene nonylphenyl ether, polyethylene glycol allyl ether, etc.), polyalkylene glycol diethers (e.g., diethylene glycol diethyl ether, diethylene glycol Polyalkylene glycol monoesters (e.g., diethylene glycol dibutyl ether, triethylene glycol dimethyl ether, tetraethylene glycol distearyl ether, polyethylene glycol dimethyl ether, etc.), polyalkylene glycol monoesters (e.g., diethylene glycol monopropionate, tetraethylene glycol monoacetate, tripropylene glycol monobutyrate, polyethylene glycol monoacetate, polyethylene glycol monopropionate, polyethylene glycol laurate, polyethylene glycol sebacate, polyethylene glycol stearate, polyethylene glycol oleate, polyoxyethylene sorbitan monolaurate, diethylene glycol acrylate, diethylene glycol methacrylate, diethylene glycol crotonate, etc.), polyalkylene glycol diesters (e.g., diethylene glycol diacetate, diethylene glycol dipropionate, diethylene glycol diacrylate,Diethylene glycol distearate, diethylene glycol dimethacrylate, tetraethylene glycol dicrotonate, polyethylene glycol diacetate, polyethylene glycol dibutyrate, polyethylene glycol diurarate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, polyethylene glycol dicrotonate, polyethylene glycol di-2-cyanoacrylate, polyethylene glycol stearyl methacrylate, polyethylene glycol lauryl acrylate, etc.), polyalkylene glycol monoether monoesters (e.g., methyl carbitol, carbitol, diethylene glycol monoethyl esters) Examples include glycol monoether compounds such as diethylene glycol monomethyl ether, polyethylene glycol monomethyl ether, polyethylene glycol monoethyl ether, tetraoxyethylene glycol monomethyl ether, polyoxyethylene glycol monolauryl ether, and polyoxyethylene glycol monononylphenyl ether (acrylates, methacrylates, crotonates, etc.), bisphenol A-polyalkylene oxide adducts, trimethylolpropane-polyalkylene oxide adducts, glycerin-polyalkylene oxide adducts, adipic acid-polyalkylene oxide adducts, and trimellitic acid-polyalkylene oxide adducts.

[0041] Among the polyalkylene oxide derivatives represented by the general formula (5) above, examples of cyclic polyalkylene oxide derivatives include 18-crown-6-ether, 15-crown-5-ether, 18-crown-5-ether, dithio-15-crown ether, dibenzo-18-crown-6-ether, dicyclohexyl-18-crown-6-ether, 1,2-naphtho-15-crown-5-ether, and 1,2-methylbenzo-18-crown-6-ether.

[0042] Examples of calixarene compounds include 37,38,39,40,41,42-hexa-(2-ethoxy-2-oxoethoxy)-calix[6]arene, 25,26,27,28-tetra-(2-ethoxy-2-oxoethoxy)-calix[4]arene, 4-tert-butylcalix[6]arene-0,0',0'',0''', 0'''', 0'''''-hexaethyl hexaacetate, 4-tert-butylcalix[5]arene-0,0',0'',0''', 0''''-pentaethyl pentaacetate, and 4-tert-butylcalix[4]arene-0,0',0'',0'''-tetraethyl tetraacetate.

[0043] The curing accelerators described above may be used alone or in combination of two or more. When a curing accelerator is included, its content is, for example, 0.005 to 5.0 parts by weight, preferably 0.01 to 1.0 parts by weight, per 100 parts by weight of alkoxyalkyl 2-cyanoacrylate.

[0044] <Other additives> In addition to the additives mentioned above, the adhesive composition of the present invention may also contain various additives commonly used in 2-cyanoacrylate adhesive compositions, such as stabilizers (e.g., radical polymerization inhibitors such as hydroquinone, hydroquinone monomethyl ether, t-butylcatechol, catechol, pyrogallol, alkyl sulfonic acids such as sulfur dioxide, methanesulfonic acid, trifluoromethanesulfonic acid, aromatic sulfonic acids such as p-toluenesulfonic acid, boron trifluoride complexes such as boron trifluoride diethyl ether complex, hydrobofluoric acid, trialkylborate, etc.), plasticizers (e.g., dimethyl phthalate, diethyl phthalate, diisodecyl phthalate, triethyl acetylcitrate, tributyl acetylcitrate, etc.), colorants (dyes, pigments, fluorescent agents), fragrances, solvents, etc.). [Examples]

[0045] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0046] <Test method> (1) Uniformity Samples were prepared by the method in accordance with JIS K6861-4, and the turbidity due to undissolved various additives in the adhesive composition before curing was visually confirmed. 〇: No undissolved matter, transparent ×: Undissolved matter exists, opaque, solid dispersion

[0047] (2) Transparency of cured product The adhesive composition was allowed to stand in an oven controlled at a temperature of 60°C and a relative humidity of 95% for 1 day to cure, and a cured product with a thickness of about 7 mm was produced. The transparency of the cured product was visually evaluated by visually recognizing the characters printed on the paper through the produced cured product. 〇: The cured product is transparent, and the characters printed on the paper can be visually recognized. ×: The cured product is cloudy or turbid, and the characters printed on the paper cannot be visually recognized or it is difficult to do so.

[0048] (3) Low contamination One drop of the adhesive composition was placed on a black EPDM test piece and allowed to stand in an oven controlled at a temperature of 40°C and a relative humidity of 80% for 1 hour to cure, and then the whitening condition of the black EPDM test piece around the cured product was visually evaluated. 〇: No whitening ×: Whitening exists

[0049] (4) Damp heat resistance A soft steel plate (JISG3141 SPCC-SB: 1.6×25×100 mm) with a polished surface was bonded using the adhesive composition in an environment of 22°C and 60%RH, and the test piece was produced by allowing it to stand for 24 hours for curing while being pressed in an environment of 22°C and 60%RH. After performing a damp heat acceleration test on the produced test piece under the conditions described in <1> to <3> below, the test piece was returned to room temperature, and the steel-steel tensile shear adhesive strength (N / mm 2 ) was measured at 25°C in accordance with JIS K6861-6. From the measurement results of the obtained steel-steel tensile shear adhesive strength, the damp heat resistance was evaluated according to the following evaluation criteria. Moist heat acceleration conditions <1>: 24-hour accelerated test at 80°C and 95% RH Moist heat acceleration conditions <2>: Accelerated test at 70°C and 95% RH for 120 hours Moist heat acceleration conditions <3>: Accelerated test at 60°C and 95% RH for 168 hours ○: The adhesive strength of all of the above (1) to (3) is 3.0 N / mm 2 That's all. ×: At least one of the above (1) to (3) has an adhesive strength of 3.0 N / mm². 2 less than

[0050] (Example 1) To 100 parts by weight of ethoxyethyl 2-cyanoacrylate, 0.5 parts by weight of 5-norbornene-2,3-dicarboxylic acid anhydride, 0.4 parts by weight of methoxypolyethylene glycol methacrylate as a curing accelerator, 9.5 parts by weight of PMMA (polymethyl methacrylate, molecular weight 450,000 g / mol) as a thickener, 0.01 parts by weight of garlic acid monohydrate as an adhesion enhancer, 410 ppm of HBF as an anionic polymerization inhibitor, and 1000 ppm of hydroquinone as a radical polymerization inhibitor were added, and the mixture was stirred under a nitrogen atmosphere at a temperature of 40-60°C for 24 hours to prepare the adhesive composition. After preparation, the above-described tests were performed on the obtained 2-cyanoacrylate adhesive composition. The results are shown in Table 1.

[0051] (Examples 2-14, Comparative Examples 1-12, Reference Example 1) An adhesive composition was prepared in the same manner as in Example 1, except that the ethoxyethyl 2-cyanoacrylate, 5-norbornene-2,3-dicarboxylic acid anhydride, curing accelerator, thickener, adhesion improver, and their amounts were changed as shown in Tables 1 and 2, and the tests described above were carried out. The results are shown in Tables 1 and 2.

[0052] The abbreviations for each additive in Tables 1 and 2 refer to the following compounds, etc.

[0053] A-1: Ethoxyethyl 2-cyanoacrylate A-2: Ethyl 2-cyanoacrylate B-1: 5-norbornene-2,3-dicarboxylic acid anhydride B-2: Methyl-5-norbornene-2,3-dicarboxylic acid anhydride B-3: 5-Norbornane-2,3-dicarboxylic acid anhydride (Hexahydro-4,7-methanoisobenzofuran-1,3-dione) B-4: 5-norbornene-2,3-dicarboxylic acid B-5: 3,3,4,4-biphenyltetracarboxylic acid dianhydride B-6: Citraconic Acid (Anhydrous) B-7: Itaconic acid anhydrous B-8: Bicyclo[2.2.2]octo-7-ene-2,3,5,6-tetracarboxylic dianhydride B-9:3-(carboxymethyl)-1,2,4-cyclopentanetricarboxylic acid 1,4:2,3-dianhydride B-10: 4,4'-(ethyn-1,2-diyl)diphthalic anhydride B-11:7-Oxabicyclo[2.2.1]hepta-5-ene-2,3-dicarboxylic acid anhydride B-12: N-phthaloyl-L-glutamic acid anhydride B-13: o-sulfobenzoic acid cyclic anhydride B-14: ENEHYDE BzDA (manufactured by ENEOS) B-15: ENEHYDE BzDAxx (manufactured by ENEOS) B-16: ENEHYDE CpODA (manufactured by ENEOS Corporation) C-1: Methoxypolyethylene glycol methacrylate D-1: PMMA (Polymethyl methacrylate, molecular weight 450,000 g / mol) E-1: Garlic acid monohydrate E-2: Pyrogallol

[0054] [Table 1]

[0055] [Table 2]

Claims

1. An adhesive composition containing (A) and (B) below, wherein the content of (B) is 0.05 to 5 parts by weight per 100 parts by weight of (A). (A) Ethoxyethyl 2-cyanoacrylate (B) 5-norbornene-2,3-dicarboxylic acid anhydride, methyl-5-norbornene-2,3-dicarboxylic acid anhydride, 5-norbornane-2,3-dicarboxylic acid anhydride, 5-norbornene-2,3-dicarboxylic acid, formula (3-1): 【Chemistry 1】 Acid anhydrides represented by the following formula (4-1): 【Chemistry 2】 at least one selected from the group consisting of acid anhydrides represented by

2. The adhesive composition according to claim 1, further comprising 0.5 to 25 parts by weight of a thickening agent per 100 parts by weight of (A) alkoxyalkyl 2-cyanoacrylate.

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