Curable composition

Abstract

To provide a curable composition giving a cured product having high strength and resistant to the lowering of elongation even by the heat aging of the cured product.SOLUTION: The present invention is a multi-component curable composition comprising a component A containing a specific reactive silyl group-containing polyoxyalkylene polymer (A), a specific reactive silyl group-containing (meth) acrylate polymer (B), and a specific epoxy resin curing agent (D), and a component B containing an epoxy resin (C).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a multi-component curable composition. [Background technology]

[0002] In order to reduce weight, structural materials in vehicles, aircraft, and railways are increasingly being replaced with lightweight materials other than steel, such as aluminum, magnesium, and carbon fiber composites, and multi-material construction, in which multiple materials are used in a single vehicle body, is becoming more common.Since joining dissimilar materials can be difficult using spot welding or laser welding, adhesive joining using adhesives is attracting attention.

[0003] Known examples of adhesives include multi-component curable compositions containing a component A that includes a polyoxyalkylene polymer having a reactive silicon group represented by general formula (i), a (meth)acrylic acid ester polymer having a reactive silicon group represented by general formula (i), and an epoxy resin curing agent having a tertiary amine, and a component B that includes an epoxy resin and a silanol condensation catalyst (see, for example, Patent Document 1). -SiX3(i) (In formula (i), X represents a hydroxyl group or a hydrolyzable group.) After curing, this curable composition gives a cured product having high strength, high rigidity and flexibility. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2019 / 163804 Summary of the Invention [Problem to be solved by the invention]

[0005] However, with conventional curable compositions, when the cured product is further subjected to heat curing after curing, the elongation may be significantly reduced or the strength of the cured product may be insufficient.

[0006] Therefore, an object of the present invention is to provide a curable composition comprising a polyoxyalkylene polymer having a reactive silicon group, a (meth)acrylic acid ester polymer having a reactive silicon group, and a component A containing an epoxy resin curing agent, and a component B containing an epoxy resin, wherein the cured product has high strength and is resistant to a decrease in elongation even when the cured product is heat-cured. [Means for solving the problem]

[0007] As a result of intensive research, the present inventors have found that in a curable composition comprising a component A containing a polyoxyalkylene polymer having a specific reactive silicon group and a (meth)acrylic acid ester polymer having a specific reactive silicon group, and a component B containing an epoxy resin, by using an epoxy resin curing agent having a specific structure as the epoxy resin curing agent, the strength of the cured product after curing is high and the elongation of the cured product is less likely to decrease even when heat-cured, which has led to the completion of the present invention.

[0008] That is, the present invention provides a composition comprising an A component including a polyoxyalkylene polymer (A) having a reactive silicon group represented by general formula (1), a (meth)acrylic acid ester polymer (B) having a reactive silicon group represented by general formula (1), and an epoxy resin curing agent (D) represented by general formula (2); Agent B containing epoxy resin (C), The present invention relates to a multi-component curable composition comprising: -SiR 1 a X 3-a (1) (In formula (1), R 1 is a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms. X represents a hydroxyl group or a hydrolyzable group. a represents 0 or 1.

[0009] [ka]

[0010] (In formula (2), Z is hydrogen, an N-containing alkyl group represented by the following general formula (3), or a linear or branched alkyl group having two or more carbon atoms; R 2 ~R 5 are each independently a linear or branched alkyl group, and Y and Y' are each independently a linear or branched alkylene group.

[0011] [ka]

[0012] (In formula (3), W is a linear or branched alkylene group, and R 6 and R 7 are each independently a straight-chain or branched alkyl group.

[0013] The present invention also relates to a cured product obtained by curing the multi-component curable composition. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a curable composition that gives a cured product with high strength after curing, and that is resistant to a decrease in elongation even when the cured product is heat-cured. DETAILED DESCRIPTION OF THE INVENTION

[0015] An embodiment of the present invention will be described below.

[0016] The curable composition according to the present embodiment comprises a component A containing a polyoxyalkylene polymer (A) having a specific reactive silicon group, a (meth)acrylic acid ester polymer (B) having a specific reactive silicon group, and a specific epoxy resin curing agent (D), and a component B containing an epoxy resin (C). According to this embodiment, it is possible to provide a curable composition that gives a cured product with high strength after curing, and that is resistant to a decrease in elongation even when the cured product is heat-cured.

[0017] <<Polyoxyalkylene polymer (A) having reactive silicon groups>> <Reactive silicon group> The curable composition according to this embodiment contains, in the component A, a polyoxyalkylene polymer (A) having a reactive silicon group represented by general formula (1). -SiR 1 a X 3-a (1) (In formula (1), R 1 is a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms. X represents a hydroxyl group or a hydrolyzable group. a represents 0 or 1.

[0018] R 1 The hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and even more preferably 1 to 3 carbon atoms. 1 Specific examples of the alkyl group include a methyl group, an ethyl group, a chloromethyl group, a methoxymethyl group, and an N,N-diethylaminomethyl group, and are preferably a methyl group, an ethyl group, a chloromethyl group, or a methoxymethyl group, and more preferably a methyl group or a methoxymethyl group. This configuration has the advantage of easily achieving both storage stability and reactivity.

[0019] Examples of X include a hydroxyl group, a halogen, an alkoxy group, an acyloxy group, a ketoximate group, an amino group, an amide group, an acid amide group, an aminooxy group, a mercapto group, an alkenyloxy group, etc. Among these, alkoxy groups such as a methoxy group and an ethoxy group are more preferred because they are mildly hydrolyzable and easy to handle, and a methoxy group and an ethoxy group are particularly preferred.

[0020] Specific examples of the reactive silicon group contained in the polyoxyalkylene polymer (A) include, but are not limited to, a trimethoxysilyl group, a triethoxysilyl group, a tris(2-propenyloxy)silyl group, a triacetoxysilyl group, a dimethoxymethylsilyl group, a diethoxymethylsilyl group, a dimethoxyethylsilyl group, a (chloromethyl)dimethoxysilyl group, a (chloromethyl)diethoxysilyl group, a (methoxymethyl)dimethoxysilyl group, a (methoxymethyl)diethoxysilyl group, an (N,N-diethylaminomethyl)dimethoxysilyl group, and an (N,N-diethylaminomethyl)diethoxysilyl group. Among these, methyldimethoxysilyl group, trimethoxysilyl group, triethoxysilyl group, (chloromethyl)dimethoxysilyl group, (methoxymethyl)dimethoxysilyl group, (methoxymethyl)diethoxysilyl group, and (N,N-diethylaminomethyl)dimethoxysilyl group are preferred because they exhibit high activity and give cured products with good mechanical properties, and trimethoxysilyl group and triethoxysilyl group are more preferred, with trimethoxysilyl group being even more preferred, because they give cured products with high rigidity.

[0021] From the viewpoint of further increasing the strength of the cured product after curing and further preventing a decrease in elongation even when the cured product is heat-cured, it is preferable that the polyoxyalkylene polymer (A) have, on average, more than one reactive silicon group per terminal. "Having, on average, more than one reactive silicon group per terminal" means that the polyoxyalkylene polymer (A) contains a polyoxyalkylene having two or more reactive silicon groups per terminal, as represented by the following general formula (4). That is, the polyoxyalkylene polymer (A) may contain only a polyoxyalkylene having two or more reactive silicon groups per terminal, or may contain both a polyoxyalkylene having two or more reactive silicon groups per terminal and a polyoxyalkylene having one reactive silicon group per terminal. Furthermore, the multiple terminals possessed by one polyoxyalkylene molecule may include both a terminal having two or more reactive silicon groups and a terminal having one reactive silicon group. Furthermore, the polyoxyalkylene polymer (A) as a whole has, on average, more than one reactive silicon group at one terminal site, but may also contain a polyoxyalkylene having a terminal site that does not have a reactive silicon group.

[0022] The terminal portion of the polyoxyalkylene polymer (A) is represented by the general formula (4):

[0023] [ka]

[0024] (In formula (4), R 1 , X is the same as in general formula (1). 8 ,R 10 are each independently a divalent linking group having 1 to 6 carbon atoms, and R 8 ,R 10 The atom bonded to each carbon atom adjacent to R is either carbon, oxygen, or nitrogen. 9 ,R 11are each independently hydrogen or a hydrocarbon group having 1 to 10 carbon atoms, and n is an integer of 1 or more.

[0025] R 8 , R 10 R may be a divalent organic group having 1 to 6 carbon atoms, may contain an oxygen atom, or may be a hydrocarbon group. The hydrocarbon group preferably has 1 to 4 carbon atoms, more preferably 1 to 3 carbon atoms, and even more preferably 1 or 2 carbon atoms. 8 Specific examples of R include CH2OCH2, CH2O, and CH2, with CH2OCH2 being preferred. 10 Specific examples of the alkyl group include CH2 and CH2CH2, with CH2 being preferred.

[0026] R 9 , R 11 The number of carbon atoms in the hydrocarbon group is preferably 1 to 5, more preferably 1 to 3, and even more preferably 1 or 2. 9 , R 11 Specific examples of include a hydrogen atom, a methyl group, and an ethyl group, with a hydrogen atom and a methyl group being preferred, and a hydrogen atom being more preferred.

[0027] In a particularly preferred embodiment, the terminal moiety represented by general formula (4) is R 8 is CH2OCH2 and R 10 is CH2 and R 9 and R 11 are each a hydrogen atom. n is preferably an integer of 1 to 10, more preferably an integer of 1 to 5, still more preferably an integer of 1 to 3, and particularly preferably 1 or 2. However, n is not limited to a single value, and may be a mixture of multiple values.

[0028] The polyoxyalkylene polymer (A) preferably has an average of more than 1.0 reactive silicon group per terminal, more preferably 1.1 or more, even more preferably 1.5 or more, and even more preferably 2.0 or more, and preferably 5 or less, more preferably 3 or less.

[0029] The number of terminal moieties having more than one reactive silicon group contained in one molecule of the polyoxyalkylene polymer (A) is preferably 0.5 or more, more preferably 1.0 or more, even more preferably 1.1 or more, and even more preferably 1.5 or more on average, and is preferably 4 or less, more preferably 3 or less.

[0030] The polyoxyalkylene polymer (A) may have reactive silicon groups in positions other than the terminal positions, but it is preferable that the reactive silicon groups are present only in the terminal positions, since this makes it easier to obtain a rubber-like cured product that has high elongation and a low elastic modulus.

[0031] The average number of reactive silicon groups per molecule of the polyoxyalkylene polymer (A) is preferably more than 1.0, more preferably 1.2 or more, even more preferably 1.3 or more, even more preferably 1.5 or more, and particularly preferably 1.7 or more. Also, it is preferably 6.0 or less, more preferably 5.5 or less, and most preferably 5.0 or less. If the average number of reactive silicon groups per molecule is 1.0 or less, a high-strength cured product may not be obtained. If the average number of reactive silicon groups per molecule exceeds 6.0, a high-elongation cured product may not be obtained.

[0032] <Main chain structure> The main chain skeleton of the polyoxyalkylene polymer (A) is not particularly limited, and examples thereof include polyoxyethylene, polyoxypropylene, polyoxybutylene, polyoxytetramethylene, polyoxyethylene-polyoxypropylene copolymer, polyoxypropylene-polyoxybutylene copolymer, etc. Among these, polyoxypropylene is preferred.

[0033] The number average molecular weight of the polyoxyalkylene polymer (A), as calculated as polystyrene by GPC, is 3,000 to 100,000, more preferably 3,000 to 50,000, and particularly preferably 3,000 to 30,000. If the number average molecular weight is less than 3,000, the amount of reactive silicon groups introduced increases, which may be inconvenient in terms of production costs, while if it exceeds 100,000, the viscosity becomes high, which tends to be inconvenient in terms of workability.

[0034] The molecular weight of the polyoxyalkylene polymer (A) can also be expressed as an end-group-converted molecular weight, which is calculated by directly measuring the end-group concentration of an organic polymer precursor before the introduction of reactive silicon groups by titration analysis based on the principles of the hydroxyl value measurement method specified in JIS K 1557 and the iodine value measurement method specified in JIS K 0070, and taking into account the structure of the organic polymer (the degree of branching determined by the polymerization initiator used).The end-group-converted molecular weight of the polyoxyalkylene polymer (A) can also be calculated by creating a calibration curve of the number average molecular weight determined by general GPC measurement of the organic polymer precursor and the end-group-converted molecular weight, and converting the number average molecular weight determined by GPC of the polyoxyalkylene polymer (A) into an end-group-converted molecular weight.

[0035] The molecular weight distribution (Mw / Mn) of the polyoxyalkylene polymer (A) is not particularly limited, but is preferably narrow, preferably less than 2.0, more preferably 1.6 or less, even more preferably 1.5 or less, particularly preferably 1.4 or less, and most preferably 1.2 or less. The molecular weight distribution of the polyoxyalkylene polymer (A) can be determined from the number average molecular weight and weight average molecular weight obtained by GPC measurement.

[0036] The main chain structure of the polyoxyalkylene polymer (A) of the present invention may be a straight chain or a branched chain, but a branched chain is preferred from the viewpoint of making it even more difficult for the elongation to decrease even when the cured product is heat-cured.

[0037] <Method for synthesizing polyoxyalkylene polymer (A)> Next, a method for synthesizing the polyoxyalkylene polymer (A) will be described. The polyoxyalkylene polymer (A) having an average of more than 1.0 reactive silicon group at one terminal site is preferably obtained by introducing two or more carbon-carbon unsaturated bonds into one terminal of a hydroxyl-terminated polymer obtained by polymerization, and then reacting the polymer with a reactive silicon group-containing compound that reacts with the carbon-carbon unsaturated bond. The above-mentioned preferred synthesis method is described below.

[0038] (polymerization) The polyoxyalkylene polymer (A) is preferably produced by a method of polymerizing an epoxy compound with an initiator having a hydroxyl group using a composite metal cyanide complex catalyst such as zinc hexacyanocobaltate glyme complex.

[0039] Examples of initiators having a hydroxyl group include those having one or more hydroxyl groups, such as ethylene glycol, propylene glycol, glycerin, pentaerythritol, low-molecular-weight polypropylene glycol, polyoxypropylene triol, allyl alcohol, polypropylene monoallyl ether, and polypropylene monoalkyl ether.

[0040] Examples of epoxy compounds include alkylene oxides such as ethylene oxide and propylene oxide, and glycidyl ethers such as methyl glycidyl ether and allyl glycidyl ether, etc. Among these, propylene oxide is preferred.

[0041] (Introduction of carbon-carbon unsaturated bonds) A preferred method for introducing two or more carbon-carbon unsaturated bonds into one terminal is to react a hydroxyl-terminated polymer with an alkali metal salt, followed by reaction with an epoxy compound having a carbon-carbon unsaturated bond and then reaction with a halogenated hydrocarbon compound having a carbon-carbon unsaturated bond. This method allows for efficient and stable introduction of reactive groups while controlling the molecular weight and molecular weight distribution of the polymer main chain through polymerization conditions.

[0042] The alkali metal salt used in this embodiment is preferably sodium hydroxide, sodium methoxide, sodium ethoxide, potassium hydroxide, potassium methoxide, or potassium ethoxide, more preferably sodium methoxide or potassium methoxide, and particularly preferably sodium methoxide in terms of availability.

[0043] The temperature when reacting with the alkali metal salt is preferably 50° C. or higher and 150° C. or lower, more preferably 110° C. or higher and 140° C. or lower. The time when reacting with the alkali metal salt is preferably 10 minutes or higher and 5 hours or lower, more preferably 30 minutes or higher and 3 hours or lower.

[0044] The epoxy compound having a carbon-carbon unsaturated bond used in this embodiment is particularly a compound represented by the general formula (5):

[0045] [ka]

[0046] (R in Equation (5) 12 , R 13 are the above R 8 , R 9 (which is the same as the above.) can be suitably used. Specifically, allyl glycidyl ether, methallyl glycidyl ether, glycidyl acrylate, glycidyl methacrylate, butadiene monoxide, and 1,4-cyclopentadiene monoepoxide are preferred in terms of reactivity, and allyl glycidyl ether is particularly preferred.

[0047] The amount of the epoxy compound having a carbon-carbon unsaturated bond used in this embodiment can be any amount, taking into consideration the amount of carbon-carbon unsaturated bonds introduced into the polymer and the reactivity. In particular, the molar ratio of the epoxy compound to the hydroxyl groups in the hydroxyl-terminated polymer is preferably 0.2 or more, more preferably 0.5 or more. Also, the molar ratio is preferably 5.0 or less, more preferably 2.0 or less.

[0048] In the present embodiment, the reaction temperature when the epoxy compound having a carbon-carbon unsaturated bond is subjected to a ring-opening addition reaction with the polymer containing a hydroxyl group is preferably 60°C or higher and 150°C or lower, and more preferably 110°C or higher and 140°C or lower.

[0049] Examples of the halogenated hydrocarbon compound having a carbon-carbon unsaturated bond used in this embodiment include vinyl chloride, allyl chloride, methallyl chloride, vinyl bromide, allyl bromide, methallyl bromide, vinyl iodide, allyl iodide, and methallyl iodide, and it is more preferable to use allyl chloride or methallyl chloride because of ease of handling.

[0050] The amount of the halogenated hydrocarbon compound having a carbon-carbon unsaturated bond to be added is not particularly limited, but the molar ratio to the hydroxyl groups in the hydroxyl-terminated polymer is preferably 0.7 or more, more preferably 1.0 or more, and is preferably 5.0 or less, more preferably 2.0 or less.

[0051] The temperature when reacting the halogenated hydrocarbon compound having a carbon-carbon unsaturated bond is preferably from 50° C. to 150° C., more preferably from 110° C. to 140° C. The reaction time is preferably from 10 minutes to 5 hours, more preferably from 30 minutes to 3 hours.

[0052] (Introduction of reactive silicon groups) The method for introducing the reactive silicon group is not particularly limited, and known methods can be used. Examples of the introduction methods are shown below. (i) A method in which a hydrosilane compound is added to a polymer having a carbon-carbon unsaturated bond by a hydrosilylation reaction. (ii) A method of reacting a polymer having a carbon-carbon unsaturated bond with a compound (also called a silane coupling agent) having both a group capable of reacting with the carbon-carbon unsaturated bond to form a bond and a reactive silicon group. Examples of the group capable of reacting with the carbon-carbon unsaturated bond to form a bond include, but are not limited to, a mercapto group.

[0053] Method (i) is preferred because the reaction is simple, the amount of reactive silicon groups introduced can be adjusted, and the physical properties of the resulting reactive silicon group-containing polyoxyalkylene polymer (A) are stable. Method (ii) is preferred because it offers a wide range of reaction options and makes it easy to increase the rate of reactive silicon groups introduced.

[0054] The hydrosilane compound that can be used in method (i) is not particularly limited, but examples thereof include trimethoxysilane, triethoxysilane, triisopropoxysilane, dimethoxymethylsilane, diethoxymethylsilane, diisopropoxymethylsilane, (methoxymethyl)dimethoxysilane, phenyldimethoxysilane, 1-[2-(trimethoxysilyl)ethyl]-1,1,3,3-tetramethyldisiloxane, tris(2-propenyloxy)silane, and triacetoxysilane.

[0055] The content of the hydrosilane compound, as a molar ratio to the carbon-carbon unsaturated bonds in the precursor polymer (number of moles of hydrosilane / number of moles of carbon-carbon unsaturated bonds), is preferably from 0.05 to 10 from the viewpoint of reactivity, and more preferably from 0.3 to 2 from the viewpoint of economy.

[0056] The hydrosilylation reaction can be accelerated by various catalysts. Examples of known catalysts that can be used include complexes of cobalt, nickel, iridium, platinum, palladium, rhodium, ruthenium, and the like. Examples include platinum supported on alumina, silica, carbon black, and other carriers; chloroplatinic acid; chloroplatinic acid complexes composed of chloroplatinic acid and alcohols, aldehydes, ketones, and the like; platinum-olefin complexes [e.g., Pt(CH=CH)(PPh), Pt(CH=CH)Cl]; platinum-vinylsiloxane complexes [Pt{(vinyl)MeSiOSiMe(vinyl)}, Pt{Me(vinyl)SiO}]; platinum-phosphine complexes [Ph(PPh), Pt(PBu)]; and platinum-phosphite complexes [Pt{P(OPh)}]. From the standpoint of reaction efficiency, it is preferable to use a platinum catalyst such as chloroplatinic acid or a platinum vinylsiloxane complex.

[0057] <<(Meth)acrylic acid ester polymer (B) having reactive silicon groups>> The curable composition according to this embodiment contains, in component A, a (meth)acrylic acid ester polymer (B) having a reactive silicon group represented by general formula (1).

[0058] The (meth)acrylic acid ester monomer constituting the main chain of the (meth)acrylic acid ester polymer (B) is not particularly limited, and various types can be used. Specifically, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and nonyl (meth)acrylate can be used. Nyl, (meth)acrylate decyl, (meth)acrylate dodecyl, (meth)acrylate phenyl, (meth)acrylate toluyl, (meth)acrylate benzyl, (meth)acrylate 2-methoxyethyl, (meth)acrylate 3-methoxybutyl, (meth)acrylate 2-hydroxyethyl, (meth)acrylate 2-hydroxypropyl, (meth)acrylate stearyl, (meth)acrylate glycidyl, (meth)acrylate (3-trimethoxysilyl)propyl, (meth)acrylate (3-dimethylsilyl).

[0033] Examples of (meth)acrylic acid monomers include (meth)acrylic acid (2-trimethoxysilyl)propyl, (2-trimethoxysilyl)ethyl (meth)acrylate, (2-dimethoxymethylsilyl)ethyl (meth)acrylate, trimethoxysilylmethyl (meth)acrylate, (dimethoxymethylsilyl)methyl (meth)acrylate, ethylene oxide adducts of (meth)acrylic acid, trifluoromethylmethyl (meth)acrylate, 2-trifluoromethylethyl (meth)acrylate, 2-perfluoroethylethyl (meth)acrylate, 2-perfluoroethyl-2-perfluorobutylethyl (meth)acrylate, perfluoroethyl (meth)acrylate, trifluoromethyl (meth)acrylate, bis(trifluoromethyl)methyl (meth)acrylate, 2-trifluoromethyl-2-perfluoroethylethyl (meth)acrylate, 2-perfluorohexylethyl (meth)acrylate, 2-perfluorodecylethyl (meth)acrylate, and 2-perfluorohexadecylethyl (meth)acrylate.

[0059] Examples of monomer units other than those mentioned above include acrylic acids such as acrylic acid and methacrylic acid; monomers containing an amide group such as N-methylolacrylamide and N-methylolmethacrylamide; monomers containing an epoxy group such as glycidyl acrylate and glycidyl methacrylate; and monomers containing a nitrogen-containing group such as diethylaminoethyl acrylate and diethylaminoethyl methacrylate.

[0060] The (meth)acrylic acid ester polymer (B) may be a polymer obtained by copolymerizing a (meth)acrylic acid ester monomer with a vinyl monomer copolymerizable therewith. The vinyl monomer is not particularly limited, and examples thereof include styrene monomers such as styrene, vinyltoluene, α-methylstyrene, chlorostyrene, styrenesulfonic acid and its salts; fluorine-containing vinyl monomers such as perfluoroethylene, perfluoropropylene, and vinylidene fluoride; silicon-containing vinyl monomers such as vinyltrimethoxysilane and vinyltriethoxysilane; maleic anhydride, maleic acid, monoalkyl esters and dialkyl esters of maleic acid; fumaric acid, monoalkyl esters and dialkyl esters of fumaric acid; maleimide, methylmaleimide, ethylmaleimide, propylmaleimide, butylmaleimide, hexylmaleimide, and octylmaleimide. Examples of suitable monomers include maleimide-based monomers such as dimaleimide, dodecylmaleimide, stearylmaleimide, phenylmaleimide, and cyclohexylmaleimide; nitrile group-containing vinyl monomers such as acrylonitrile and methacrylonitrile; amide group-containing vinyl monomers such as acrylamide and methacrylamide; vinyl ester-based monomers such as vinyl acetate, vinyl propionate, vinyl pivalate, vinyl benzoate, and vinyl cinnamate; alkenyl-based monomers such as ethylene and propylene; conjugated diene-based monomers such as butadiene and isoprene; vinyl chloride, vinylidene chloride, allyl chloride, and allyl alcohol, and a plurality of these can also be used as copolymerization components.

[0061] Among the (meth)acrylic acid ester-based polymers obtained from the above-mentioned monomers, copolymers composed of styrene-based monomers and (meth)acrylic acid-based monomers are preferred because of their excellent physical properties, (meth)acrylic acid ester-based polymers composed of acrylic acid ester monomers and methacrylic acid ester monomers are more preferred, and acrylic acid ester-based polymers composed of acrylic acid ester monomers are particularly preferred.

[0062] The (meth)acrylic acid ester polymer (B) has a reactive silicon group represented by the above-mentioned general formula (1). As the reactive silicon group contained in the (meth)acrylic acid ester polymer (B), the reactive silicon groups described above for the polyoxyalkylene polymer (A) can be used, but among them, trimethoxysilyl groups and triethoxysilyl groups are more preferred because they give a cured product with high rigidity. The (meth)acrylic acid ester polymer (B) and the polyoxyalkylene polymer (A) may have the same or different general formula (1).

[0063] The reactive silicon group equivalent of the (meth)acrylic acid ester polymer (B) is not particularly limited, but is preferably 0.2 mmol / g or more, more preferably 0.5 mmol / g or more, and even more preferably 0.6 mmol / g or more. The reactive silicon group equivalent is preferably 2.0 mmol / g or less, and from the viewpoint of suppressing a decrease in elongation of the cured product, more preferably 1.0 mmol / g or less. Furthermore, in order to obtain a highly rigid cured product, the reactive silicon group equivalent is particularly preferably 0.6 mmol / g or more and 1.0 mmol / g or less.

[0064] The method for introducing reactive silicon groups into a (meth)acrylic acid ester polymer is not particularly limited, and the following methods can be used, for example: (iv) A method in which a compound having a polymerizable unsaturated group and a reactive silicon-containing group is copolymerized with the above-mentioned monomer. This method tends to introduce reactive silicon groups randomly into the main chain of the polymer. (v) A method in which a (meth)acrylic acid ester polymer is polymerized using a mercaptosilane compound having a reactive silicon-containing group as a chain transfer agent. This method allows for the introduction of reactive silicon groups into the polymer terminals. (vi) A method in which a compound having a polymerizable unsaturated group and a reactive functional group (V group) is copolymerized, followed by reaction with a compound having a reactive silicon group and a functional group reactive with the V group. Specific examples include a method in which 2-hydroxyethyl acrylate is copolymerized followed by reaction with an isocyanate silane having a reactive silicon-containing group, and a method in which glycidyl acrylate is copolymerized followed by reaction with an aminosilane compound having a reactive silicon-containing group. (vii) A method of modifying the terminal functional groups of a (meth)acrylic acid ester polymer synthesized by living radical polymerization to introduce reactive silicon groups. A (meth)acrylic acid ester polymer obtained by living radical polymerization can be easily modified to introduce functional groups at the polymer terminals, and by modifying this, reactive silicon groups can be introduced at the polymer terminals.

[0065] Examples of silicon compounds that can be used to introduce reactive silicon groups into the (meth)acrylic acid ester polymer (B) using the above method include the following compounds. Compounds having a polymerizable unsaturated group and a reactive silicon group that can be used in method (iv) include 3-(trimethoxysilyl)propyl (meth)acrylate, 3-(triethoxysilyl)propyl (meth)acrylate, (trimethoxysilyl)methyl (meth)acrylate, and (triethoxysilyl)methyl (meth)acrylate. 3-(trimethoxysilyl)propyl (meth)acrylate is particularly preferred.

[0066] Examples of the mercaptosilane compound having a reactive silicon-containing group used in the method (v) include 3-mercaptopropyltrimethoxysilane, (mercaptomethyl)trimethoxysilane, and the like.

[0067] Examples of compounds having a reactive silicon group and a functional group reactive with the V group that can be used in method (vi) include isocyanate silane compounds such as 3-isocyanate propyl trimethoxysilane, 3-isocyanate propyl triethoxysilane, isocyanate methyl trimethoxysilane, and isocyanate methyl triethoxysilane; epoxy silane compounds such as 3-glycidoxypropyl trimethoxysilane, 3-glycidoxypropyl triethoxysilane, glycidoxymethyl trimethoxysilane, and glycidoxymethyl triethoxysilane; and aminosilane compounds such as 3-aminopropyl trimethoxysilane, 3-aminopropyl triethoxysilane, aminomethyl trimethoxysilane, aminomethyl triethoxysilane, N-cyclohexyl aminomethyl trimethoxysilane, and N-cyclohexyl aminomethyl triethoxysilane.

[0068] In the above method (vii), any modification reaction can be used. For example, a method using a compound having a silicon group and a functional group capable of reacting with the terminal reactive group obtained by polymerization, or a method using a compound having a double bond and a functional group capable of reacting with the terminal reactive group to introduce a double bond into the polymer terminal, and then introducing a reactive silicon group into the double bond by hydrosilylation or the like, can be used.

[0069] These methods may be used in any combination. For example, by combining method (vi) and method (v), a (meth)acrylic acid ester polymer (B) having reactive silicon groups at both the molecular chain terminals and / or side chains can be obtained.

[0070] From the viewpoint that the elongation percentage is more resistant to decrease even when the cured product is heat-cured, the (meth)acrylic acid ester polymer (B) preferably contains 30% by weight or more, more preferably 32 to 65% by weight, and even more preferably 34 to 55% by weight of alkyl (meth)acrylates having an alkyl carbon number of 4 or more, based on all monomers.

[0071] On the other hand, from the viewpoint of further increasing the strength of the cured product, the (meth)acrylic acid ester polymer (B) preferably contains less than 30% by weight, more preferably 5 to 27% by weight, and even more preferably 15 to 25% by weight of alkyl (meth)acrylates having an alkyl carbon number of 4 or more, based on the total monomers.

[0072] The monomer composition of the (meth)acrylic acid ester polymer (B) can be selected depending on the application and purpose.

[0073] The number average molecular weight of the (meth)acrylic acid ester polymer (B) is not particularly limited, but is preferably 500 to 50,000, more preferably 500 to 30,000, and particularly preferably 1,000 to 10,000, in terms of polystyrene, as measured by GPC.

[0074] Methods of blending a (meth)acrylic acid ester polymer (B) with a polyoxyalkylene polymer (A) have been proposed in JP-A Nos. 59-122541, 63-112642, 6-172631, and 11-116763, etc. Alternatively, a method of polymerizing a (meth)acrylic acid ester monomer in the presence of a polyoxypropylene polymer having a reactive silicon group can be used.

[0075] The weight ratio (A):(B) of the polyoxyalkylene polymer (A) to the (meth)acrylic acid ester polymer (B) is preferably 70:30 to 50:50. This range further increases the strength of the cured product after curing, and makes it even more difficult for the elongation of the cured product to decrease even when heat-cured. Furthermore, the (A):(B) ratio is preferably 70:30 to 57:43, and more preferably 65:35 to 55:45.

[0076] <<Epoxy resin (C)>> The curable composition according to this embodiment contains an epoxy resin (C) in the B component.

[0077] The epoxy resin (C) is preferably an epoxy resin having at least two epoxy groups in one molecule, which has the advantage of improving the tear strength of the cured product.

[0078] Examples of the epoxy resin (C) include flame-retardant epoxy resins such as epichlorohydrin-bisphenol A epoxy resins, epichlorohydrin-bisphenol F epoxy resins, and glycidyl ethers of tetrabromobisphenol A, novolac epoxy resins, hydrogenated bisphenol A epoxy resins, glycidyl ether epoxy resins of bisphenol A propylene oxide adducts, p-oxybenzoic acid glycidyl ether ester epoxy resins, m-aminophenol epoxy resins, diaminodiphenylmethane epoxy resins, urethane-modified epoxy resins, various alicyclic epoxy resins, N,N-diglycidylaniline, N,N-diglycidyl-o-toluidine, triglycidyl isocyanurate, polyalkylene glycol diglycidyl ether, glycidyl ethers of polyhydric alcohols such as glycerin, hydantoin epoxy resins, and epoxidized products of unsaturated polymers such as petroleum resins, but are not limited to these. Epoxy resins having at least two epoxy groups per molecule are preferred because they have high reactivity during curing and the cured product easily forms a three-dimensional network. More preferred examples include bisphenol A type epoxy resins and novolac type epoxy resins.

[0079] The epoxy resin (C) is preferably used so that the weight ratio of the total of the polyoxyalkylene polymer (A) and the (meth)acrylic acid ester polymer (B) to the epoxy resin (C) [(A+B):(C)] is 80:20 to 60:40. If the ratio of (A+B) is greater than 80%, the strength decreases, and if it is less than 60%, the flexibility decreases and the composition becomes too hard. Furthermore, a ratio of 75:25 to 65:45 is more preferable in terms of the balance between flexibility and strength.

[0080] <<Epoxy resin hardener (D)>> The curable composition according to this embodiment contains an epoxy resin curing agent (D) represented by the following general formula (2) in component A. According to this configuration, the curable composition has high strength after curing, and the elongation of the cured product is unlikely to decrease even when the cured product is heat-cured.

[0081] [ka]

[0082] In formula (2), Z is hydrogen, an N-containing alkyl group represented by the following general formula (3), or a linear or branched alkyl group having two or more carbon atoms; R 2 ~R 5 are each independently a straight-chain or branched alkyl group, and Y and Y' are each independently a straight-chain or branched alkylene group.

[0083] [ka]

[0084] In formula (3), W is a linear or branched alkylene group, and R 6 and R 7 are each independently a straight-chain or branched alkyl group.

[0085] In formula (2), R 2 ~R 5 Each R is independently a linear or branched alkyl group. 2 ~R 5 The alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and even more preferably 1 to 3 carbon atoms. 2 ~R 5 The alkyl group may be either straight-chain or branched, but is preferably straight-chain.

[0086] In formula (2), Y and Y' are each independently a linear or branched alkylene group. The number of carbon atoms in the alkylene groups Y and Y' is preferably 1 to 15, more preferably 1 to 10, and even more preferably 1 to 5. The alkylene groups Y and Y' may be linear or branched, but are preferably linear.

[0087] In formula (2), Z is hydrogen, an N-containing alkyl group represented by general formula (3), or a linear or branched alkyl group having two or more carbon atoms.

[0088] When Z is an N-containing alkyl group represented by general formula (3), R 6 and R 7 Each R is independently a linear or branched alkyl group. 6 and R 7 The alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and even more preferably 1 to 3 carbon atoms. 6 and R 7 The alkyl group may be either linear or branched, but is preferably linear. When Z is a linear or branched alkyl group having 2 or more carbon atoms, the number of carbon atoms in the alkyl group is, for example, 2 to 10, preferably 1 to 5, and more preferably 1 to 3. The alkyl group may be either linear or branched, but is preferably linear.

[0089] In formula (3), each W is independently a linear or branched alkylene group. The number of carbon atoms in the alkylene group of W is preferably 1 to 15, more preferably 1 to 10, and even more preferably 1 to 5. The alkylene group of W may be linear or branched, but is preferably linear.

[0090] Each alkyl group and each alkylene group in the epoxy resin curing agent represented by general formula (2) may be independently substituted with any substituent, such as ethyl, propyl, ethylene, or propylene.

[0091] In this embodiment, the epoxy resin curing agent represented by the general formula (2) is an epoxy resin curing agent represented by the general formula (3), wherein Z is hydrogen or an N-containing alkyl group represented by the general formula (3), W, Y, and Y′ are linear alkylene groups having 3 carbon atoms, and R 2 ~R 7 is preferably a methyl group.

[0092] From the viewpoint that the elongation percentage is more resistant to decrease even when the cured product is heat-cured, Z in formula (2) is preferably an N-containing alkyl group represented by formula (3).

[0093] Examples of epoxy resin curing agents represented by general formula (2) include tris(3-dimethylaminopropyl)amine ("JEFFADD (registered trademark) MW-760" manufactured by Huntsman Japan Co., Ltd.), tetramethyliminobispropylamine ("JEFFCAT Z-130" manufactured by Huntsman Japan Co., Ltd.), and the like.

[0094] The content of the epoxy resin curing agent (D) is preferably 1 to 50 parts by weight, more preferably 5 to 40 parts by weight, and even more preferably 10 to 25 parts by weight, relative to 100 parts by weight of the epoxy resin (C).

[0095] The curable composition according to the present embodiment preferably contains the polyoxyalkylene polymer (A), the (meth)acrylic acid ester polymer (B), the epoxy resin (C), and the epoxy resin curing agent (D) in a total amount of 40 to 90% by weight, more preferably 50 to 80% by weight, and even more preferably 55 to 75% by weight.

[0096] <<Silanol condensation catalyst>> The curable composition according to the present embodiment preferably contains a silanol condensation catalyst for the purpose of promoting the condensation reaction of the reactive silicon groups of the polyoxyalkylene polymer (A) and the (meth)acrylic acid ester polymer (B) and chain-extending or crosslinking the polymers.

[0097] Examples of silanol condensation catalysts include organotin compounds, metal carboxylates, amine compounds, carboxylic acids, and alkoxy metals.

[0098] Specific examples of organotin compounds include dibutyltin dilaurate, dibutyltin dioctanoate, dibutyltin bis(butyl maleate), dibutyltin diacetate, dibutyltin oxide, dibutyltin bis(acetylacetonate), dioctyltin bis(acetylacetonate), dioctyltin dilaurate, dioctyltin distearate, dioctyltin diacetate, dioctyltin oxide, a reaction product of dibutyltin oxide with a silicate compound, a reaction product of dioctyltin oxide with a silicate compound, and a reaction product of dibutyltin oxide with a phthalate ester.

[0099] Specific examples of the metal carboxylate include tin carboxylate, bismuth carboxylate, titanium carboxylate, zirconium carboxylate, iron carboxylate, etc. The metal carboxylate can be a combination of the following carboxylic acids and various metals.

[0100] Specific examples of the amine compound include amines such as octylamine, 2-ethylhexylamine, laurylamine, and stearylamine; nitrogen-containing heterocyclic compounds such as pyridine, 1,8-diazabicyclo[5,4,0]undecene-7 (DBU), and 1,5-diazabicyclo[4,3,0]nonene-5 (DBN); guanidines such as guanidine, phenylguanidine, and diphenylguanidine; biguanides such as butylbiguanide, 1-o-tolylbiguanide, and 1-phenylbiguanide; amino group-containing silane coupling agents; and ketimine compounds.

[0101] Specific examples of carboxylic acids include acetic acid, propionic acid, butyric acid, 2-ethylhexanoic acid, lauric acid, stearic acid, oleic acid, linoleic acid, neodecanoic acid, and versatic acid.

[0102] Specific examples of alkoxy metals include titanium compounds such as tetrabutyl titanate titanium tetrakis(acetylacetonate) and diisopropoxytitanium bis(ethylacetoacetate), aluminum compounds such as aluminum tris(acetylacetonate) and diisopropoxyaluminum ethylacetoacetate, and zirconium compounds such as zirconium tetrakis(acetylacetonate).

[0103] The content of the silanol condensation catalyst (E) is preferably 0.001 to 20 parts by weight, more preferably 0.01 to 15 parts by weight, and particularly preferably 0.01 to 10 parts by weight, per 100 parts by weight of the total of the polyoxyalkylene polymer (A) and the (meth)acrylic acid ester polymer (B).

[0104] <<Water(F)>> Water may be added to the component B of the composition of this embodiment. By adding water, curing of the polyoxyalkylene polymer (A) and the (meth)acrylic acid ester polymer (B) is promoted when the components A and B are mixed.

[0105] The amount of water (F) added is preferably 0.1 to 10 parts by weight, more preferably 0.2 to 7 parts by weight, and even more preferably 0.5 to 4 parts by weight, per 100 parts by weight of the total of the polyoxyalkylene polymer (A) and the (meth)acrylic acid ester polymer (B). The composition of this embodiment may also contain a component C containing water (F) in addition to components A and B. In this case, the composition of this embodiment will be a three-component type.

[0106] <<Other additives>> The composition of this embodiment may contain other additives in addition to the polyoxyalkylene polymer (A), (meth)acrylic acid ester polymer (B), epoxy resin (C), epoxy resin curing agent (D), silanol condensation catalyst, and water. Examples of other additives include plasticizers, stabilizers, fillers, rheology control agents, silane coupling agents, light stabilizers, UV absorbers, tackifying resins, other resins, solvents, diluents, photocurable substances, oxygen-curable substances, surface modifiers, silicates, curability regulators, radical inhibitors, metal deactivators, antiozonants, phosphorus-based peroxide decomposers, lubricants, pigments, mildew inhibitors, flame retardants, and foaming agents.

[0107] <Plasticizer> The curable composition according to this embodiment may contain a plasticizer. Examples of the plasticizer include polypropylene glycol, diisonoyl phthalate, 2-ethoxyethanol, bis(2-ethylhexyl) phthalate, and diisodecyl phthalate. These plasticizers may be used alone or in combination of two or more.

[0108] The content of the plasticizer is preferably 5 to 40 parts by weight, more preferably 10 to 30 parts by weight, based on 100 parts by weight of the total of the polyoxyalkylene polymer (A) and the (meth)acrylic acid ester polymer (B).

[0109] <Stabilizer> The curable composition according to this embodiment may contain a stabilizer. Examples of stabilizers include antioxidants (antiaging agents). The use of an antioxidant can improve the weather resistance of the cured product. Examples of antioxidants include aromatic secondary amines, hindered phenols, monophenols, bisphenols, and polyphenols. Specific examples of antioxidants are described in JP-A-4-283259 and JP-A-9-194731. These stabilizers may be used alone or in combination of two or more.

[0110] The content of the stabilizer is preferably 0.1 to 10 parts by weight, more preferably 0.2 to 5 parts by weight, based on 100 parts by weight of the total of the polyoxyalkylene polymer (A) and the (meth)acrylic acid ester polymer (B).

[0111] <Filler> The curable composition according to this embodiment may contain a filler. Examples of fillers include calcium carbonate (e.g., heavy calcium carbonate, colloidal calcium carbonate, etc.), magnesium carbonate, diatomaceous earth, clay, talc, titanium oxide, silica (e.g., fumed silica, wet silica (precipitated silica), crystalline silica, fused silica, etc.), silicic anhydride, hydrous silicic acid, alumina, carbon black, ferric oxide, fine aluminum powder, zinc oxide, activated zinc oxide, PVC powder, PMMA powder, glass fiber and filament, etc. Silica (particularly precipitated silica and fumed silica) is more preferably used because it can efficiently impart thixotropy. These fillers may be used alone or in combination of two or more.

[0112] The content of the filler is preferably 1 to 300 parts by weight, more preferably 10 to 250 parts by weight, per 100 parts by weight of the total of the polyoxyalkylene polymer (A) and the (meth)acrylic acid ester polymer (B).

[0113] <Rheology control agent> To improve workability, the curable composition according to this embodiment may contain a rheology control agent. Examples of the rheology control agent include polyamide waxes, hydrogenated castor oil derivatives, and metal soaps such as calcium stearate, aluminum stearate, and barium stearate. These rheology control agents may be used alone or in combination of two or more.

[0114] The content of the rheology control agent is preferably 0.1 to 20 parts by weight, more preferably 1 to 10 parts by weight, based on 100 parts by weight of the total of the polyoxyalkylene polymer (A) and the (meth)acrylic acid ester polymer (B).

[0115] <Silane coupling agent> The curable composition according to the present embodiment may contain a silane coupling agent. Examples of the silane coupling agent include vinyl group-containing silanes such as vinyltrimethoxysilane; amino group-containing silanes such as N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldimethoxysilane, N-β-aminoethyl-γ-aminopropyltrimethoxysilane, N-β-aminoethyl-γ-aminopropylmethyldimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, and (2-aminoethyl)aminomethyltrimethoxysilane; γ-isocyanatepropyltrimethoxysilane; Examples of suitable silane coupling agents include isocyanate group-containing silanes such as γ-isocyanatepropyltriethoxysilane, γ-isocyanatepropylmethyldimethoxysilane, α-isocyanatemethyltrimethoxysilane, and α-isocyanatemethyldimethoxymethylsilane; mercapto group-containing silanes such as γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, and γ-mercaptopropylmethyldimethoxysilane; and epoxy group-containing silanes such as γ-glycidoxypropyltrimethoxysilane and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. These silane coupling agents may be used alone or in combination of two or more.

[0116] The content of the silane coupling agent is preferably 0.1 to 20 parts by weight, more preferably 0.5 to 10 parts by weight, based on 100 parts by weight of the total of the polyoxyalkylene polymer (A) and the (meth)acrylic acid ester polymer (B).

[0117] <Light stabilizer> The curable composition according to this embodiment may contain a light stabilizer. The use of a light stabilizer can prevent photo-oxidative degradation of the cured product. Examples of light stabilizers include benzotriazole-based, hindered amine-based, and benzoate-based compounds, with hindered amine-based compounds being particularly preferred.

[0118] The content of the light stabilizer is preferably 0.1 to 10 parts by weight, particularly preferably 0.2 to 5 parts by weight, per 100 parts by weight of the total of the polyoxyalkylene polymer (A) and the (meth)acrylic acid ester polymer (B).

[0119] <UV absorber> The curable composition according to this embodiment may contain an ultraviolet absorber. The use of an ultraviolet absorber can improve the surface weather resistance of the cured product. Examples of ultraviolet absorbers include benzophenone-based, benzotriazole-based, salicylate-based, substituted tolyl-based, and metal chelate-based compounds. Benzotriazole-based compounds are particularly preferred, and examples thereof include those commercially available under the names Tinuvin P, Tinuvin 213, Tinuvin 234, Tinuvin 326, Tinuvin 327, Tinuvin 328, Tinuvin 329, and Tinuvin 571 (all manufactured by BASF).

[0120] The content of the ultraviolet absorber is preferably 0.1 to 10 parts by weight, particularly preferably 0.2 to 5 parts by weight, per 100 parts by weight of the total of the polyoxyalkylene polymer (A) and the (meth)acrylic acid ester polymer (B).

[0121] <Tackifying resin> The curable composition according to the present embodiment may contain a tackifier resin for the purpose of improving adhesion and adhesion to a substrate. The tackifier resin is not particularly limited, and any commonly used tackifier resin can be used. Specific examples include terpene resins, aromatic modified terpene resins, hydrogenated terpene resins, terpene-phenol resins, phenol resins, modified phenol resins, xylene-phenol resins, cyclopentadiene-phenol resins, coumarone-indene resins, rosin resins, rosin ester resins, hydrogenated rosin ester resins, xylene resins, low-molecular-weight polystyrene resins, styrene copolymer resins, styrene block copolymers and hydrogenated products thereof, petroleum resins (e.g., C5 hydrocarbon resins, C9 hydrocarbon resins, C5C9 hydrocarbon copolymer resins, etc.), hydrogenated petroleum resins, DCPD resins, etc. These may be used alone or in combination of two or more.

[0122] The content of the tackifier resin is preferably 2 to 100 parts by weight, more preferably 5 to 50 parts by weight, and even more preferably 5 to 30 parts by weight, per 100 parts by weight of the total of the polyoxyalkylene polymer (A) and the (meth)acrylic acid ester polymer (B). If the content is less than 2 parts by weight, it is difficult to obtain adhesion and bonding effects to the substrate, and if the content exceeds 100 parts by weight, the viscosity of the composition becomes too high, which may make it difficult to handle.

[0123] The curable composition of the present embodiment may be a two-component curable composition consisting of a component A and a component B.

[0124] <<Preparation of Curable Composition>> The curable composition of this embodiment is preferably prepared as a two-component composition by blending a polyoxyalkylene polymer (A), an acrylic ester polymer (B), and an epoxy curing agent (D) as component A, and an epoxy resin (C) as component B, and mixing components A and B before use. Furthermore, water may be added to component B to promote the curing of the polyoxyalkylene polymer (A) and the acrylic ester polymer (B).

[0125] <<Surface treatment of adherends>> The curable composition of this embodiment exhibits good adhesion to various adherends, including plastics, metals, and composites. Furthermore, when used as an adhesive for nonpolar materials such as polypropylene or engineering plastics with rigid molecular chains such as polyphenylene sulfide, the adherends can be surface-treated in advance by a known method to enhance adhesion to these adherends and obtain stable adhesive strength. For example, surface treatment techniques such as sanding, flame treatment, corona discharge, arc discharge, and plasma treatment can be used. Plasma treatment is preferred because it causes minimal damage to the adherend and provides stable adhesion. These surface treatments are also effective for removing release agents used during molding and remaining on the adherend surface.

[0126] <<Application>> The curable composition of this embodiment is suitable for use as an adhesive composition, and can be used as a sealing material, adhesive, pressure-sensitive adhesive, waterproofing material, etc. for buildings, ships, automobiles, roads, etc. Among the above-mentioned uses, the cured product obtained by curing the curable composition of this embodiment is more preferably used as an adhesive, particularly a structural adhesive. When joining dissimilar materials, it is preferable to cover the joint with a sealer to prevent corrosion. As the sealer, a polymer having a reactive silicon group as described in the present application can be used. The curable composition of this embodiment is preferably used as an adhesive for automobile parts such as vehicle panels, large vehicle parts such as trucks and buses, train parts, aircraft parts, ship parts, electrical parts, various machine parts, etc.

[0127] The curable composition of the present embodiment provides a cured product with high strength after curing, and the elongation of the cured product is unlikely to decrease even when heat-cured, thereby providing a cured product with high long-term adhesive reliability.

[0128] The cured product of the present embodiment is a cured product obtained by curing the curable composition.

[0129] It should be noted that the present invention is not limited to the above-described embodiment. Furthermore, the present invention is not limited to the above-described effects. Furthermore, the present invention can be modified in various ways without departing from the spirit of the present invention.

[0130] [Disclosure items] Each of the following sections is a disclosure of a preferred embodiment.

[0131] [Item 1] an agent A containing a polyoxyalkylene polymer (A) having a reactive silicon group represented by general formula (1), a (meth)acrylic acid ester polymer (B) having a reactive silicon group represented by general formula (1), and an epoxy resin curing agent (D) represented by general formula (2); Agent B containing epoxy resin (C), A multi-component curable composition comprising: -SiR1 a X 3-a (1) (In formula (1), R 1 is a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms. X represents a hydroxyl group or a hydrolyzable group. a represents 0 or 1. [ka] (In formula (2), Z is hydrogen, an N-containing alkyl group represented by the following general formula (3), or a linear or branched alkyl group having two or more carbon atoms; R 2 ~R 5 are each independently a linear or branched alkyl group, and Y and Y' are each independently a linear or branched alkylene group. [ka] (In formula (3), W is a linear or branched alkylene group, and R 6 and R 7 are each independently a straight-chain or branched alkyl group. [Item 2] 2. The multi-component curable composition according to item 1, wherein the polyoxyalkylene polymer (A) has a branched main chain structure. [Item 3] 3. The multi-component curable composition according to item 1 or 2, wherein the (meth)acrylic acid ester polymer (B) contains 30% by weight or more of alkyl (meth)acrylates having an alkyl carbon number of 4 or more based on all monomers. [Item 4] The terminal portion of the polyoxyalkylene polymer (A) is represented by the general formula (4): [ka] (In formula (4), R 1 , X is the same as in general formula (1). 8 ,R 10 are each independently a divalent linking group having 1 to 6 carbon atoms, and R 8 ,R 10The atom bonded to each carbon atom adjacent to R is either carbon, oxygen, or nitrogen. 9 ,R 11 are each independently hydrogen or a hydrocarbon group having 1 to 10 carbon atoms, and n is an integer of 1 or more. 4. The multi-component curable composition according to any one of items 1 to 3, wherein the polyoxyalkylene polymer (A) has, on average, more than one reactive silicon group at one terminal site. [Item 5] 5. The multi-component curable composition according to any one of items 1 to 4, wherein the weight ratio of the polyoxyalkylene polymer (A):(meth)acrylic acid ester polymer (B) is 70:30 to 50:50. [Item 6] 6. The multi-component curable composition according to any one of items 1 to 5, wherein a weight ratio of the total of the polyoxyalkylene polymer (A) and the (meth)acrylic acid ester polymer (B) to the epoxy resin (C) is 80:20 to 60:40. [Item 7] 7. The multi-component curable composition according to any one of items 1 to 6, which is a two-component curable composition consisting of component A and component B. [Item 8] A cured product obtained by curing the multi-component curable composition according to any one of items 1 to 7. [Example]

[0132] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[0133] The number average molecular weight (Mn) and weight average molecular weight (Mw) in the examples are GPC molecular weights measured under the following conditions. Liquid delivery system: Tosoh HLC-8120GPC Column: Tosoh TSK-GEL H type Solvent: THF Molecular weight: Polystyrene equivalent Measurement temperature: 40℃

[0134] The end group-based molecular weight in the examples is a molecular weight calculated by determining the hydroxyl value according to the measurement method of JIS K 1557 and the iodine value according to the measurement method of JIS K 0070, taking into consideration the structure of the organic polymer (the degree of branching determined by the polymerization initiator used).

[0135] The average number of carbon-carbon unsaturated bonds introduced per terminal of the polymer (Q) shown in the examples was calculated by the following formula. (Average number of introductions) = [unsaturated group concentration (mol / g) of polymer (Q) calculated from iodine value - unsaturated group concentration (mol / g) of precursor polymer (P) calculated from iodine value] / [hydroxyl group concentration (mol / g) of precursor polymer (P) calculated from hydroxyl value].

[0136] The average number of silyl groups introduced per terminal of the polymer (A) shown in the examples was calculated by NMR measurement.

[0137] (Synthesis Example 1) Using polyoxypropylene glycol with a number-average molecular weight of approximately 2,000 as an initiator, propylene oxide was polymerized in the presence of a zinc hexacyanocobaltate glyme complex catalyst to obtain polyoxypropylene (P-1) with a number-average molecular weight of 28,500 (17,700 molecular weight calculated as the terminal group) and a molecular weight distribution (Mw / Mn) of 1.21, bearing hydroxyl groups at both ends. To the hydroxyl-terminated polyoxypropylene, 1.0 molar equivalent of sodium methoxide was added as a 28% methanol solution. After removing the methanol by vacuum devolatilization, 1.0 molar equivalent of allyl glycidyl ether was added to the hydroxyl groups of the hydroxyl-terminated polyoxypropylene, and the reaction was carried out at 130°C for 2 hours. Subsequently, 0.28 molar equivalent of sodium methoxide in methanol was added to remove the methanol, and 1.79 molar equivalents of allyl chloride was added to convert the terminal hydroxyl groups to allyl groups. 100 parts by weight of the resulting crude allyl-terminated polyoxypropylene was mixed and stirred with 300 parts by weight of n-hexane and 300 parts by weight of water, and the mixture was centrifuged to remove the water. The resulting hexane solution was then mixed and stirred with another 300 parts by weight of water, and the water was again centrifuged to remove the water. The hexane was then removed by devolatilization under reduced pressure. This yielded polyoxypropylene (Q-1) with a terminal structure containing two or more carbon-carbon unsaturated bonds. It was found that polymer (Q-1) had an average of 2.0 carbon-carbon unsaturated bonds introduced into each terminal site.

[0138] To 100 parts by weight of the resulting polyoxypropylene having an average of 2.0 carbon-carbon unsaturated bonds at one terminal, 72 ppm of platinum divinyldisiloxane complex (a 3 wt% isopropanol solution calculated as platinum) was added, and while stirring, 2.2 parts by weight of trimethoxysilane was slowly added dropwise. The mixture was allowed to react at 90°C for 2 hours, and then the unreacted trimethoxysilane was distilled off under reduced pressure to obtain a linear reactive silicon group-containing polyoxypropylene polymer (A-1) having an average of 1.6 trimethoxysilyl groups at one terminal, an average of 3.2 silicon groups per molecule, and a number average molecular weight of 28,500.

[0139] (Synthesis Example 2) Using polyoxypropylene triol with a number-average molecular weight of approximately 3,000 as an initiator, propylene oxide was polymerized with a zinc hexacyanocobaltate glyme complex catalyst to obtain terminal hydroxyl-containing polyoxypropylene (P-2) with a number-average molecular weight of 25,630 (terminal-based molecular weight of 17,440) and a molecular weight distribution Mw / Mn = 1.21. To the hydroxyl-terminated polyoxypropylene, 1.0 molar equivalent of sodium methoxide was added as a 28% methanol solution. After removing the methanol by vacuum devolatilization, 1.0 molar equivalent of allyl glycidyl ether was added to the hydroxyl groups of the hydroxyl-terminated polyoxypropylene, and the reaction was carried out at 130 °C for 2 hours. Subsequently, 0.28 molar equivalent of sodium methoxide in methanol was added to remove the methanol, and 1.79 molar equivalents of allyl chloride was added to convert the terminal hydroxyl groups to allyl groups. 100 parts by weight of the resulting crude allyl-terminated polyoxypropylene was mixed and stirred with 300 parts by weight of n-hexane and 300 parts by weight of water, and the mixture was centrifuged to remove the water. The resulting hexane solution was then mixed and stirred with another 300 parts by weight of water, and the water was again centrifuged to remove the water. The hexane was then removed by devolatilization under reduced pressure. This resulted in a polyoxypropylene having a terminal structure with two or more carbon-carbon unsaturated bonds. It was found that this polymer had an average of 2.0 carbon-carbon unsaturated bonds introduced into each terminal site.

[0140] To 100 parts by weight of the resulting polyoxypropylene having an average of 2.0 carbon-carbon unsaturated bonds at one terminal, 72 ppm of platinum divinyldisiloxane complex (3 wt% isopropanol solution in terms of platinum) was added, and 2.9 parts by weight of trimethoxysilane was slowly added dropwise while stirring. The resulting mixture was reacted at 90°C for 2 hours, and then the unreacted trimethoxysilane was distilled off under reduced pressure to obtain a branched, reactive silicon-containing polyoxypropylene polymer (A-2) containing an average of 1.6 trimethoxysilyl groups at one terminal, an average of 4.8 trimethoxysilyl groups per molecule, and a number-average molecular weight of 25,630.

[0141] (Synthesis Example 3) A four-necked flask equipped with a stirrer was charged with 42.9 parts by weight of isobutanol and heated to 105°C under a nitrogen atmosphere. A mixed solution of 65.0 parts by weight of methyl methacrylate, 25.0 parts by weight of 2-ethylhexyl acrylate, 10.0 parts by weight of 3-methacryloxypropyltrimethoxysilane, 7.2 parts by weight of 3-mercaptopropyltrimethoxysilane, and 1.8 parts by weight of 2,2'-azobis(2-methylbutyronitrile) dissolved in 16.4 parts by weight of isobutanol was added dropwise over 5 hours. A mixed solution of 0.7 parts by weight of 2,2'-azobis(2-methylbutyronitrile) dissolved in 6.3 parts by weight of isobutanol was then added and polymerized at 105°C for 2 hours to obtain an isobutanol solution (solids content 60%) of a reactive silicon group-containing (meth)acrylic acid ester polymer (B-1) having an average of 1.6 silicon groups per molecule and a number-average molecular weight of 2,300. The reactive silicon group equivalent weight of the solid content is 0.72 mmol / g. The polymer (B-1) contains 23.3% by weight of alkyl (meth)acrylates in which the alkyl has 4 or more carbon atoms, based on the total monomers.

[0142] (Synthesis Example 4) A four-neck flask equipped with a stirrer was charged with 42.9 parts by weight of isobutanol, and the temperature was raised to 105° C. under a nitrogen atmosphere. A mixed solution prepared by dissolving 37.6 parts by weight of methyl methacrylate, 36.0 parts by weight of butyl acrylate, 14.1 parts by weight of stearyl methacrylate, 6.5 parts by weight of 3-methacryloxypropyltrimethoxysilane, 5.8 parts by weight of 3-mercaptopropyltrimethoxysilane, and 1.8 parts by weight of 2,2′-azobis(2-methylbutyronitrile) in 16.4 parts by weight of isobutanol was added dropwise thereto over 5 hours. A mixed solution of 0.7 parts by weight of 2,2'-azobis(2-methylbutyronitrile) in 8.8 parts by weight of isobutanol was then added, and polymerization was carried out at 105°C for 2 hours to obtain an isobutanol solution (solids content 60%) of a reactive silicon group-containing (meth)acrylic acid ester polymer (B-2) having an average of 1.4 silicon groups per molecule and a number average molecular weight of 2,520. The reactive silicon group equivalent of the solids was 0.56 mmol / g. The polymer (B-2) contains 50.1% by weight of alkyl (meth)acrylates in which the alkyl has 4 or more carbon atoms, based on the total monomers.

[0143] Example 1 42 parts by weight of the reactive silicon group-containing polyoxypropylene polymer (A-1) obtained in Synthesis Example 1 and the reactive silicon group-containing (meth)acrylic acid ester polymer (B-1) obtained in Synthesis Example 3 were mixed to a solid content of 28 parts by weight, and the isobutanol was then heated to remove the volatiles. The resulting mixture was mixed with 4 parts by weight of Actocol P-23 (polypropylene glycol, molecular weight: 4,800, manufactured by Mitsui Chemicals, Inc.) as a plasticizer, 1 part by weight of Nocrac CD (antioxidant, manufactured by Ouchi Shinko Chemical Industry Co., Ltd.) as a stabilizer, 1 part by weight of Adekastab AO-60 (antioxidant, manufactured by ADEKA Corporation), 12 parts by weight of CCR-S10 (colloidal calcium carbonate, manufactured by Shiraishi Kogyo Co., Ltd.) as a filler, 0.05 parts by weight of Asahi Thermal (carbon black, manufactured by Asahi Carbon Co., Ltd.), and 3 parts by weight of Crayvallac SL (fatty acid amide wax, manufactured by ARKEMA) as a rheology control agent using a planetary mixer, and then dehydrated by heating under reduced pressure at 120°C for 1 hour. The resulting composition was cooled and mixed with 6 parts by weight of MW760 (tris(3-dimethylaminopropyl)amine, manufactured by HUNTSMAN) as an epoxy resin curing agent (D), 3 parts by weight of A-171 (vinyltrimethoxysilane, manufactured by Momentive) as a dehydrating agent, 2 parts by weight of KBM-603 (N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.) as an adhesion promoter, and 0.5 parts by weight of TIBKAT223 (dioctyltin bisacetylacetonate, manufactured by TIB Chemicals) as a silanol condensation catalyst (E) to obtain Agent A. 32 parts by weight of jER828 (bisphenol A type epoxy resin, manufactured by Mitsubishi Chemical Corporation) as epoxy resin (C), 8.8 parts by weight of Actocol P-23 (polypropylene glycol, molecular weight: 4,800, manufactured by Mitsui Chemicals, Inc.) as plasticizer, 20 parts by weight of CCR-S10 (colloidal calcium carbonate, manufactured by Shiraishi Kogyo Co., Ltd.) as filler, 1.2 parts by weight of NIPGEL CX-200 (wet silica, manufactured by Tosoh Silica Corporation) as rheology control agents, 2 parts by weight of R-820 (titanium oxide, manufactured by Ishihara Sangyo Kaisha, Ltd.), and 2 parts by weight of water (F) were mixed using a planetary mixer to obtain Agent B.

[0144] (Mixing method) The components A and B prepared in Example 1 were filled into a two-liquid mixing cartridge (manufactured by NORDSON Corporation) so that the weight ratio of component A:component B was 1.6:1 or 2:1 (volume ratio).Components A and B were mixed using a static mixer with an element diameter of 10 mm and 24 stages of elements to obtain a mixture.

[0145] (Evaluation of tensile properties) A sheet approximately 2 mm thick was made from the mixture of Agents A and B and cured for 7 days at 23°C and 50% RH. The resulting sheet was punched into No. 3 dumbbell shapes (JIS K 6251), and a tensile strength test was carried out at 23°C and 50% RH to measure the breaking strength (TB) and elongation (EB). Furthermore, the specimens were aged at 50°C for 7 days, and the elongation at break (EB) was measured. The retention rate of elongation at break (EB) was then calculated (calculation formula: (EB aged for 7 days at 23°C, 50% RH, and then aged for 7 days at 50°C) / (EB aged for 7 days at 23°C, 50% RH)). The tensile properties were measured at a tension speed of 50 mm / min using an autograph (AGS-X) manufactured by Shimadzu Corp. The results are shown in Table 1.

[0146] (Examples 2 to 5, Comparative Examples 1 to 4) Compositions were prepared in the same manner as in Example 1 except that the formulation was changed as shown in Table 1, and strength and elongation retention were determined. The results are shown in Table 1.

[0147] [Table 1]

[0148] (1): Polypropylene glycol (Mitsui Chemicals, Inc.) (2): Diisononyl phthalate (J-Plus Corporation) (3): Tris(3-dimethylaminopropyl)amine (HUNTSMAN) (4): (N'-(3-(dimethylamino)propyl)-N,N-dimethyl)1,3-propanediamine (HUNTSMAN) (5): 2,4,6-tris(dimethylaminomethyl)phenol (EVONIK) (6): Antioxidant (Ouchi Shinko Chemical Industry Co., Ltd.) (7): Antioxidant (ADEKA Corporation) (8): Colloidal calcium carbonate (Shiraishi Kogyo Co., Ltd.) (9): Carbon black (Asahi Carbon Co., Ltd.) (16): Fatty acid amide wax (ARKEMA) (10): Vinyltrimethoxysilane (Momentive Corporation) (11): N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd.) (12): Dioctyltin bis(acetylacetonate) (13): Bisphenol A epoxy resin (Mitsubishi Chemical Corporation) (14): Wet silica (Tosoh Silica Corporation) (15): Titanium oxide (Ishihara Sangyo Kaisha, Ltd.)

[0149] The epoxy resin curing agent (D) represented by the general formula (2), tris(3-dimethylaminopropyl)amine (MW760) and (N'-(3-(dimethylamino)propyl)-N,N-dimethyl)1,3-propanediamine (Z-130), are compounds represented by the following formulas (6) and (7), respectively. Furthermore, 2,4,6-tris(dimethylaminomethyl)phenol (Ancamine K54), hexamethyltriethylenetetramine, and N,N,N',N'-tetramethylethylenediamine, which are epoxy resin curing agents other than the epoxy resin curing agent (D), are compounds represented by the following formulas (8) to (10), respectively.

[0150] [ka]

[0151] [ka]

[0152] [ka]

[0153] [ka]

[0154] [ka]

[0155] As shown in Table 1, Examples 1 to 5 had high strength and elongation retention rates. On the other hand, in Comparative Examples 1 to 3 in which another epoxy resin curing agent, Ancamine K54 or hexamethyltriethylenetetramine, was used instead of the epoxy resin curing agent (D), the strength and elongation retention rate were low. Furthermore, in Comparative Example 4, in which another epoxy resin curing agent, N,N,N',N'-tetramethylethylenediamine, was used instead of the epoxy resin curing agent (D), the strength was low. Therefore, it can be seen that the present invention can provide a curable composition that gives a cured product with high strength after curing and that is resistant to a decrease in elongation even when the cured product is heat-cured.

[0156] Example 2, in which the main chain structure of the polyoxyalkylene polymer (A) was a branched chain, had a higher elongation retention rate than Example 1, which was the same as Example 2 except that the main chain structure was a straight chain.

[0157] Example 5, in which the (meth)acrylic acid ester polymer (B) contained 50.1 wt % of alkyl (meth)acrylates whose alkyl group had 4 or more carbon atoms based on all monomers, had a higher elongation retention rate than Example 3, which was the same as Example 5 except that the (meth)acrylic acid ester polymer (B) contained 23.3 wt % of alkyl (meth)acrylates whose alkyl group had 4 or more carbon atoms based on all monomers. On the other hand, Example 3 had a higher strength than Example 5.

[0158] Example 2, in which Z in general formula (2) is an N-containing alkyl group represented by general formula (3), had a higher elongation retention rate than Example 4, which was the same as Example 2 except that Z in general formula (2) was hydrogen.

Claims

1. an agent A containing a polyoxyalkylene polymer (A) having a reactive silicon group represented by general formula (1), a (meth)acrylic acid ester polymer (B) having a reactive silicon group represented by general formula (1), and an epoxy resin curing agent (D) represented by general formula (2); Agent B containing an epoxy resin (C), A multi-component curable composition comprising: -SiR １ ａ X ３－ａ (1) (In formula (1), R １ represents a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms; X represents a hydroxyl group or a hydrolyzable group; and a represents 0 or 1. 【Chemistry 1】 (In formula (2), Z is hydrogen, an N-containing alkyl group represented by the following general formula (3), or a linear or branched alkyl group having two or more carbon atoms; R ２ ~R ５ are each independently a linear or branched alkyl group, and Y and Y' are each independently a linear or branched alkylene group. 【Chemistry 2】 (In formula (3), W is a linear or branched alkylene group, and R ６ and R ７ are each independently a straight-chain or branched alkyl group.

2. The multi-component curable composition according to claim 1 , wherein the main chain structure of the polyoxyalkylene polymer (A) is a branched chain.

3. 3. The multi-component curable composition according to claim 1, wherein the (meth)acrylic acid ester polymer (B) contains 30% by weight or more of alkyl (meth)acrylates having an alkyl group with 4 or more carbon atoms, based on the total weight of all monomers.

4. The terminal portion of the polyoxyalkylene polymer (A) is represented by the general formula (4): 【Transformation 3】 (In formula (4), R １ , X is the same as in general formula (1). ８ , R １０ are each independently a divalent linking group having 1 to 6 carbon atoms, and R ８ , R １０ The atom bonded to each carbon atom adjacent to R is carbon, oxygen, or nitrogen. ９ , R １１ are each independently hydrogen or a hydrocarbon group having 1 to 10 carbon atoms; and n is an integer of 1 or more.

3. The multi-component curable composition according to claim 1, wherein the polyoxyalkylene polymer (A) has, on average, more than one reactive silicon group at one terminal site.

5. 3. The multi-component curable composition according to claim 1, wherein the weight ratio of the polyoxyalkylene polymer (A):(meth)acrylic acid ester polymer (B) is 70:30 to 50:

50.

6. 3. The multi-component curable composition according to claim 1, wherein a weight ratio of the total of the polyoxyalkylene polymer (A) and the (meth)acrylic acid ester polymer (B) to the epoxy resin (C) is 80:20 to 60:

40.

7. 3. The multi-component curable composition according to claim 1, which is a two-component curable composition consisting of component A and component B.

8. A cured product obtained by curing the multi-component curable composition according to claim 1 or 2.

Images